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Current Issue: Keep clear of Malpractice when providing veneers!
Previous Issue: Is total caries removal contraindicated?
Previous Issue: Prelude, the latest self-etching primer
Previous Issue: Ozone Therapy
Previous Issue: Zero Invasion Dentistry
Previous Issue: New Years 2002
Previous Issue: Stop Sensitivity!
Dear Fellow Bondodontists,
Wow, another year flew by. We must be having fun!! I think Mary and I continue to live in the fast lane.
2007 will be another great year for our programs. The Tahoe seminar on June 9 will feature Prof. Edward Lynch from Queen’s University in Belfast. He in the inventor of the ozone therapy marketed by KaVo as Healozone. Many of you have heard me speak briefly on the topic in the last 3 years; here is the source of the best and most complete information. Eddie is also an expert on caries and its prevention so I asked him to present a summary of current concepts, what works and what does not. It is beginning to look like caries risk assessment and management may become the “standard of care” to preclude malpractice litigation. There are some commercially driven products but let’s get the straight scoop from an expert. If you have a cervical sensitivity, perhaps Eddie or I can treat it on the spot. It only takes about 10 seconds and I have never missed! I will be presenting some selected restorative topics that supplement Eddie’s presentation.
The Yosemite program on November 1-4 will feature Prof. Harald Heymann, one of our most popular speakers. He will be speaking on multiple restorative dentistry topics, among them: Insights into Abfractions and Desensitization, Direct Restoratives: Proven Solutions to Clinical Problems, Tooth Whitening: The Great White Hype! Harald strikes a prefect balance between science and practicality. The seminar is held at the Ahwahnee Hotel where Mary negotiated some very good room rates, not generally available to the public. The early November dates have proven to be excellent times for visiting Yosemite. This year the Glacier Point road was open and the views simply spectacular. A Glacier Point photo courtesy of our guest speaker, Dr. Ron Jackson:
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The penguin picture was taken on recent scouting trip, previewing a planned Antarctic cruise. If you are interested, let us know so that we can give you advance notice. We have a great Alaska cruise (sorry, no penguins there) scheduled for July 27. The cruise features a special guest speaker, Dr. David Winkler from London, one of Europe’s finest clinicians. New Zealand is scheduled this year too. (New Zealand does have a few penguins.) It’s Christchurch for June 29, Wellington July 4 and Auckland for July 7. There are usually some great airfare deals (especially the fly/drive deals) at that time of year. Winters in New Zealand are generally mild and a nice time to be there.
Have a great 2007.
Sincerely,
Dr. Raymond Bertolotti
In 2005-2006, I was an expert witness in several malpractice lawsuits involving veneers. Clinical success should be sufficient to keep you out of trouble but unfortunately nothing is 100% successful, so be cautious. I offer the following opinions on how to avoid such litigation. Basically, it is by proper informed consent. Here is a slide I have been using recently as part of my Bondodontics 2006 presentation. I will discuss each issue below.
• Veneers are not permanent
• Veneering is irreversible
• Many times bleaching is preferred
• Many times orthodontics (include “invisible braces”) is preferred
• Occasional speech problems and food trapping
• Occasionally crowns are required to replace
• Post-op sensitivity can occur
Some of the attorneys I have worked with recommend even more extensive informed consent such as for complications of anesthesia and even tooth loss. I personally think these are so unlikely that I don’t generally include them, any more than I would with routine operative dentistry. Of course I’m not an attorney, so you might wish to consult your own attorney about this matter.
Permanent: Amazingly, a frequent problem that leads to litigation is that patients somehow think veneers are “permanent”. Now just what in restorative dentistry is permanent? I can only think of extraction. So let’s be sure to inform about expected longevity and especially what happens when they do need replacement. Now think about how advantageous it would be to replace veneers that are entirely in enamel, compared to those placed on heavily prepped teeth, well into dentin. If you don’t know the procedure for conservative veneers, may I humbly suggest that you attend my seminar? I also recommend Ross Nash Seminars for such. (If you can’t make it to a seminar, one top reference is: Fracture load and mode of failure of ceramic veneers with different preparations. Castelnuevo et al, J Pros Dent 2000;83:171-180).
Irreversible: DenMat has been advocating “no prep” (reversible) veneers since the 1980’s. Lately they seem to have revived the concept with some heavy promotion which has led to increased public and dentist awareness. They seem to have mastered the process of producing very thin veneers. Of course Den Mat can work well with prepped teeth too. On most well aligned teeth, I prefer conservative in-enamel preparations for enhanced esthetics and potentially better periodontal response. I tell most of my patients about the advantages I perceive of conservative (in enamel) tooth reduction but of course also the trade-offs compared to “no prep” veneers. My occasional “no-prep” veneers are mostly done on lingually tipped incisors or on peg-shaped lateral incisors. If you do prep, especially heavily and that often means into dentin, be sure that your patients understand. They should be told that occasionally a crown (and perhaps endo too, to be safe) would be required if the veneer fails. Here is the typical malpractice scenario: Doc GP provides veneers on heavily prepped teeth after learning the technique at a commercially-driven course. Failure happens. (Debonding and/or sensitivity are the most common.) Patient seeks help from a specialist, often (unfortunately) a prosthodontist (small p or capital “P”) who knows little about bonding or veneers. Prosthodontist informs patient that teeth are over-prepped and now require crowns (of course with more tooth reduction, duh!). Something goes wrong, such as now needing endo. Litigation follows now if it did not follow the prosthodontist’s initial treatment. On one recent case, it was quite clear to me that the prosthodontist (small p in this case, but you would not know it from his web site) deserved most of the blame. However it was Doc GP who was sued.
Bleaching: In just about every court case, “bleaching” or “whitening” comes up. If it seems like a reasonable alternative, was the patient informed? Be sure that conversation and especially a rejection is witnessed; have your witness (a DA, perhaps) make a separate chart entry or initial the existing one. If my assistant was not present for the consultation, I make sure she is there for a summary conversation. In my seminars, I am showing some amazing bleach results for tetracycline stained teeth so it could be a reasonable alternative.
Orthodontics: Orthodontics should include “invisible braces” as part of the informed consent. I was recently asked in court if the “standard of care” should include “Invisalign” in the informed consent. Again, be sure to document well if this treatment option is rejected. This is one which I am personally very, very careful to document.
Speech problems: I do not generally inform about this one since it is very rare that patients do not adapt. I often tell patients that they can expect some strange feeling teeth for a “few days” but beyond that I am not very concerned. However if you make some radical changes, shall we say “Extreme”, it would be a point worth considering in the informed consent.
Crowns to replace: I simply do not inform as such because it has not, to this day, occurred for me. I have done thousands of veneers, the count is well into five figures. However my veneers are quite conservative; beware if you are a heavy “tooth cutter” using only pressed ceramics, like I see so often in court.
Post-op sensitivity: Again, a non-problem for me. I think it’s because I am so tooth conservative and I believe that I do have a good handle on bonding. I can recall a few teeth that have had some sensitivity, but not more that one in any veneer case. Only once did it not go away within a few days and actually that tooth received endo. The endodontist told me and the patient that it was highly likely the veneer did not cause the problem. BTW, the endodontist stated that a crown after endo would be contraindicated; the veneered tooth would be stronger! Right-on!! (There is a nice reference on this subject; Cumulative effects of successive restorative procedures on anterior crown flexure: intact vs. veneered incisors. Magne P and Douglas W, Quint Inter 2000;31:5-18.)
p.s. I was a witness in a weird case where the patient was completely happy with her veneer shade until about 2 years later, when she changed her mind about the ludicrous white shade she selected. Fortunately it was well documented that she picked the shade and confirmed her good choice later. Then the typical scenario: prosthodontist (small p) makes crowns since allegedly too much tooth was removed (absolutely stupid in this case since enamel remained nearly everywhere). The lesson to be learned here is document and witness so it’s not a matter of one dentist against one patient. Juries are sometimes sympathetic and unpredictable but with documentation, less likely to make a bad judgment. BTW, plaintiff’s expert stated that veneers are contraindicated on lower incisors, duh. Beware of what you may be up against.
Smile design:
The first question is smile design. I try to avoid computer simulations since they can over-promise. What I often do is mock up in the mouth, using either Show Off (Cosmedent) or Estelite Sigma (Tokuyama, my absolute favorite composite). Second, we decide prep, no-prep and if prep, how much. If the tooth length needs to be reduced, just “cut off” the tooth with a black alcohol soluble marker pen as part of the mockup. An example is below:
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| Pre-op | "Shortened" | Composite Mockup Added |
Tooth Preparation:
I tend to follow the “Castelnuevo prep” design, that is plan for 2 mm of incisal free-standing porcelain, a lingual butt joint and a facial reduction of about ½ the enamel. (See reference above.) I do not routinely break the contacts.
Impression:
I prefer putty/wash for accuracy and ease of impression. Putty/wash seems to be overlooked by a lot of Americans but it is the most popular in Europe. I specifically do not use “H and H” for veneers since they are not subgingival, where H and H is preferred. I like Danville’s Star VPS putty since it does not stick to my gloved fingers. For the wash, I prefer the First Quarter Light or for a big case, the slower Star VPS Light. To prevent tears of the impression where it goes through below the contact, it is helpful to place some of Ultradent’s Blue Blockout (ships with Opalescence), to the lingual area and light cure it. The resulting impressions are very clear and free of tears:
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Temporaries:
I etch a small spot in the center of the facial surface, and then apply a light curing enamel bond such as Danville’s E-Bond. For one or two veneers, I then hand sculpt some Estelite Sigma composite to the facial surface and light cure it. Thus the composite is spot bonded. For a larger case, I use TurboTemp 2 or Luxatemp (Turbo-Temp 2 is a far better value) in a preliminary impression. The preliminary impression is made after mocking up the teeth so that the proposed changes are in the temps. After the TurboTemp 2 is self cured in the mouth for about two minutes, I remove the impression and light cure the E-Bond through the TurboTemp 2. It attaches to the previously light cured E-Bond.
Try-in:
For try-in, silane (such as S-Bond) is placed on the HF lab etched veneers while they are clean. Now there are two recommended procedures. For years I have used Danville’s E-Bond on the veneer to protect the silane from contamination. First, I try-in for fit with the silane and E-Bond on the veneers. Then I add composite (currently, Accolade PV Try-in composite, see below) to the E-Bond and try in for color. The E-Bond is light sensitive so it has some effect on limiting the try-in time. The second procedure, a great innovation from Danville, uses Accolade PV Try-in Composite placed directly on the silane, no E-Bond. The veneer is tried in for fit and color simultaneously. Accolade PV Try-in is real composite but has no light sensitive initiators, thus allowing accurate color evaluation with nearly unlimited try-in time. Using a composite rather than a glycerine based try-in materials not only speeds the procedure but also eliminates the possibility of contamination by the try-in material. After try-in, the trick is to remove at least 50% of the Accolade PV Try-in composite and then replace it with the normal catalyzed Accolade PV composite. The remnant Try-in material is polymerized by what’s known as “diffusion polymerization”. This technique is unique in the industry and I very highly recommend it. Danville supplies complete technique instructions with the Accolade PV kit. For further efficiency of try-in, I try-in with two shades of composite simultaneously as illustrated below. By observing the two shades, I can “dial in” a composite blend if required or just choose the best shade. If there is more than one veneer, I usually try-in with different shades on each veneer. Sometimes just a “right half” and a “left half” on a big case. The unlimited try-in time allows the patient to take as much time as required for try-in and I proceed only when they are happy with the shade. No more remakes on me! As my good friend, Dr. Tom Hughes of Colorado says, the patient “buys the shade” before the veneers are bonded. They can take as much time as they want.
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| Prepared Tooth | Veneer Try-in with two shades of Accolade PV Try-in Composite | Completion |
Bonding the veneers:
After try-in is satisfactory and patient “buys the shade”, the veneers with Try-in Accolade PV composite are removed from the teeth. The teeth are pumiced with a prophy cup to remove all try-in materials from the teeth. The veneers are brushed with Prelude adhesive #2 (included in Accolade PV kits), to dissolve most of the Try-in composite. Then regular Accolade PV is placed on the veneers, not completely rid of Try-in material. These materials are light sensitive so protect from light. Etch the teeth with phosphoric acid (the self etching primer, Prelude #1, is not used) and place the Prelude #2 adhesive on the teeth and then place the veneers. Light cure as usual. As many of you know, I like Clearfil Photo Bond on teeth in situations where complete light cure is doubtful. Photo Bond is dual cured and will perform well even if not light cured. So Photo Bond would be a wise choice for opaque or thick veneers while Prelude is fine for light curable veneers.
Clearfil Ceramic Primer (Kuraray)
One of the most confusing current issues is how to bond to various ceramic materials. We all know how to bond to “silica” based, HF etched porcelain, by using silane. Many of you know my favorite silane product, Clearfil Porcelain Bond Activator, which eliminates the need for the HF etching step on silica based porcelain. This is a unique property of Activator, no HF required. (Ref: Fatigue span of porcelain repair systems. Llobell A et al, Int J Pros 1992;5:205-213.) Activator is not used by itself, it is mixed with an appropriate Clearfil primer. However if the ceramic is not made of silica and therefore not HF-etchable [examples Lava (3M/Espe) and Procera (Nobel)] silane does not work and Activator does not work either. Matter of fact, any and all silanes act like a separator! So I have recommended sandblast with aluminum oxide followed by either Panavia or Bistite. This method for bonding is confirmed by the research of Prof. Mathias Kern in Germany. An alternative, although more trouble and more expensive but certainly working well, is to use Rocatec or CoJet (3M/Espe). All of this has proven to be very confusing. Kuraray has solved the confusion (or perhaps introduced more) by combining two technologies, the silane properties of Clearfil Porcelain Bond Activator and the adhesion monomer of Panavia. The product is called Clearfil Ceramic Primer which bonds to just about any ceramic (silica or non-silica based), no HF etching required. “If it’s white, just sandblast and use Clearfil Ceramic Primer; it will bond”. The Ceramic Primer will link to just about any composite luting cement such as Variolink 2 (Vivadent) or Kuraray’s new Esthetic Cement. Of course Ceramic Primer also works with Panavia but it is redundant for non-etchable ceramics. Now at the risk of confusion, Ceramic Primer works on non-precious metals too. If this is all overwhelming, consider attending my seminar. We will clear up any confusion. I will give you a cookbook procedure. Since Clearfil Ceramic Primer is a brand new product, it might not yet be on the dealer shelves. I bet that Tin Man will be among the first to stock it: (800) 554-6394.
Accolade SRO (Danville)
Two of the best selling flowable composites in the USA are StarFlow and “high viscosity StarFlow” known as Accolade. StarFlow had the highest compressive strength of all flowable composites in CRA testing. It was found to be stronger than some “packable” composites. StarFlow and Accolade compare to Herculite in strength yet both are flowable composites! Now there is a new version, Accolade SRO, meaning “Super RadiOpaque”. SRO has the highest radiopacity of any known composite, making it ideal as a first increment for posterior composites. Now highest strength and highest radiopacity have been combined. The SRO is not quite as esthetic as the regular Vita shades of StarFlow so it is recommended for first increments only.
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What determines the wear rate of composites?
I keep seeing higher and higher filler contents of composite advertised. I presume that a lot of docs would equate this higher filler content with lower wear rate. This conclusion is most likely incorrect. Filler size has a greater influence on wear rate than does percent filler. A great example is Vivadent’s HelioMolar. That material clearly outperforms all other composites for wear resistance (and stays polished too) yet it has a very low percentage fill. The reason is simple: the small particle size of the “microfill” filler. Please note that while HelioMolar is a superb choice as a final increment, it may be less that ideal for the bulk of the filling since it is relatively weak. So for years I have recommended that a hybrid composite be used underneath the final layer of HelioMolar. Personally, I use the flowable hybrid StarFlow as a “base”. These days I bond it with Danville’s Prelude SE.
Ray's Current Recommendations:
Class I, II, and V composites
Prelude SE Bond OR Clearfil SE Bond
Class III and IV Composites
Total etch and Clearfil Photo Bond OR Total etch and Prelude #2
Bonded Amalgam
Total etch, Microprime G, Clearfil Photo Bond
Indirect restorations that require dual-curing (eg. crowns)
Panavia F 2.0 (Normal set: ED Primer; Slow set: total etch, Photo Bond) OR Prelude SE with Link, then dual cure composite such as Starfill 2B or Variolink 2
Indirect restorations that are light curable (eg. veneers)
Total etch, Prelude #2 OR Clearfil Photo Bond and Accolade PV
Bases
Fiji VII, only if residual caries, otherwise no base
Bonding to existing porcelain or composite
Sandblasting followed by Clearfil Photo Bond mixed with Porcelain Bond Activators
Bonding to existing metal
Sandblasting followed by Panavia F 2.0 (tin-plate after sandblasting if precious metal, OR use Tokuyama Metaltite if not tin-plated)
Issue 27, January 2006, Is total caries removal contraindicated?
Dear Fellow Bondodontists,
Thanks for your tremendous support last year. Our seminars continue to grow, thanks to your attendance and referrals. Also, thanks for all your kind mail and e-mail. It is really heartwarming to hear about all the clinical successes; that is what keeps me in the seminar business these days.
You might be interested to know that a typical seminar has repeat attendance of over 70%. I know that would not happen if you were not having clinical success!! Mary and I are trying to figure out what it takes to motivate those who have not attended. Where do they get their CE? What kind of dentistry are they practicing? If you have any ideas, please let me know. (rbertolott@aol.com or www.adhesion.com)
We don’t pretend to have the only good seminar; there are lots of them. However I am proud to be stressing minimal invasion consistent with meeting the patients esthetic expectations. I see far too much teaching of highly invasive techniques, certainly not in the patient’s best interest. Much of this appears to be commercially driven.
In 2005, we had two awesome guest speakers. First, Dr. Geoff Knight at Hawaii and Tahoe. Geoff’s highlight for me was his silver iodide arresting of caries. This presents a serious challenge to the Healozone (KaVo) concept. (Neither technology is available in the USA at present.) Then at Yosemite, Prof. Van Thompson, now of NYU. Van further expanded on caries removal, further explaining why total removal of caries may be contra-indicated. Is this heresy or what? Just remember total etch and how that was perceived by the “experts” when it was introduced!! You can learn more about Geoff’s concepts at www.dentalk.au and about Van’s lecture on www.TinMandental.com (click on downloads, presentations).
This year we are proud to present Dr. Ron Jackson at Yosemite. Ron really needs no introduction, being one of the masters of direct resin dentistry. The dates are November 2-4. Be warned, this one is likely to sell out due to the speaker and the location. Early November is great at Yosemite, no crowds, trees in autumn colors, and hopefully the first storm to feed the falls. There is no snow this early. Mary has negotiated some great room rates at Yosemite.
Tahoe, southshore, at Stateline is on for October 14 at Harvey’s. The guest speaker will be Dr. Jerry Denehy, the mentor for many of the top resins dentists worldwide. We have not yet scheduled Hawaii. Watch the web site for an announcement. (www.adhesion.com).
Have a great year.
Sincerely,
Ray
Porcelain veneers 20 years later
Now that we are approaching 25 years experience with bonded porcelain veneers, we really know a lot about them. We know what prep results in the strongest veneers, we know how strong they really are and we know that they can last for a very long time.
The biggest clinical problem I have encountered with veneers is the try-in materials. I have avoided the use of try-in pastes for two reasons. First, glycerin based try-in pastes are generally very poor representations of the final composite shades. Some brands are better than others, but most are terrible. Second, glycerin based try-in pastes are sources of veneer contamination. Unless thoroughly removed, they will weaken the bond strength of composite to the HF etched porcelain veneers and can often result in a complete de-bond. Now there is a revolutionary try-in system that allows us to dial-in the shade, eliminating the try-in problems.
Longevity of veneers
I have personally placed thousands of porcelain veneers since I was introduced to the concept1 by Dr. John Calamia in 1983. So how long do veneers last? In my practice, a very long time, at least as long as crowns. The most common reason for replacement is gingival recession, mostly after 10 years of service. The second most common reason is the patient wanting to upgrade to even whiter veneers. (Ten years ago, shade A2 was normal. Now it’s whiter than B1.) Fracture has been rare and de-bonding non-existent. I estimate that the rate of fracture is around 2% at 10 years. Fracture most often occurs at the incisal edge, from trauma, or at the cervical area when the veneer is bonded to dentin, presumably from tooth flexure. This result compares favorably to all-porcelain crowns and PFM crowns.
Here are two representative long-term veneer recalls. One is 21 years recall and the other one 14 years. The 14 year case (shade A2) is holding just fine but the older one showed excessive gingival recession and the veneers were consequently replaced. Since the veneer preps were only in enamel, removal and remake was done without anesthesia. The third picture is a porcelain veneer that was chipped by bumping with a Coke bottle after 9 years of service. Fortunately, sectional porcelain was able to repair this one and it’s still looking good after 6 more years. (The procedure for bonding sectional porcelain has been in my seminars for years now; if you are not familiar with the technique let me know and I can e-mail it to you.)
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| Veneers at 14 year recall. | Veneers at 21 year recall. |
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| Veneer chipped by trauma. | Successful repair, 6 years later |
Pressed ceramic vs. “feldspathic” veneers
More than 95% of my veneers are fabricated with “feldspathic” porcelain, that is from a porcelain slurry brushed onto foil or a refractory model and then fired. These feldspathic veneers are in contrast to what we call pressed ceramics. The most commonly used porcelains for my veneers are Ceramco 2, Noritake, d-Sign, and Finesse. (Some of these porcelains are not technically “feldspathic”, since they are not made from the mineral feldspar. However they are fabricated like feldspathic ones.) The reason that I choose feldspathic veneers in that they can be made thinner than pressed ceramic with more than one color of porcelain throughout the veneer. Pressed ceramics rely on surface color to produce multi-hued veneers. Unfortunately if I grind the surface to re-shape the veneer, as I often do, this surface color is lost. I reserve the use of pressed ceramic for veneers that are around 1 mm thick or more (say, a peg-shaped lateral incisor). The pressed ceramics seem to have a better chameleon quality for these thick veneers, very useful when a shape change but not a color change is desired. My veneers average 0.5 mm in the thickest places. That is roughly half of the enamel thickness, allowing the tooth preparation to be entirely in enamel. There are obvious advantages, including no need for anesthesia for the preparations nor for the bonding procedure. Pressed ceramics generally need a lot more tooth reduction.
So why are pressed ceramics seemingly more popular than feldspathics? I think it is due largely to commercially driven teaching institutes who are in cahoots with the pressed ceramic manufacturers. Another factor, as I am told, is that it is easier to train a technician to make pressed ceramic veneers than to make feldspathic veneers. Yet another factor may be that some dentists expect a veneer to be a lot like a crown, that is final in color when delivered, no matter how it is bonded. Only thick veneers can accomplish this objective. However they rarely do; when was the last time you received a perfect single central incisor crown or thick veneer? Thin veneers are translucent and are meant to be “dialed-in” for color at chairside, something you can’t do with thick veneers. I find the dial-in capability to be a great advantage, allowing me to match almost anything. With a single veneer, the final dial-in of a thin veneer is usually easy! All you need is the right veener bonding system and ideally a perfectly shaded try-in system.
Preferred tooth preparation
Fortunately we have some good research on tooth preparation. Castelnuevo et al.2 found that 2 mm of free standing porcelain produced the strongest veneer and furthermore that a lingual chamfer actually reduced strength compared to a lingual butt joint. This is great news since it is easy to prepare for 2 mm of porcelain and a lingual butt joint. Just hack off some incisal tooth and leave the lingual margin as-cut. Just be sure to round the facial-incisal angle after you prepare the facial reduction. (Of course if the tooth is worn, you will need to reduce the incisal less that 2 mm since you are planning for 2 mm of porcelain.) The facial-incisal preparation allows for various paths of insertion and for extending into the gingival interproximal areas.
A very nice paper by Magne and Douglas3 stated “each subsequent reduction in tooth structure resulted in a substantial increase in crown flexibility, even after restoration” and “veneered incisors should be considered to be similar to natural teeth and restored accordingly.” Let’s consider what they are saying. The more tooth reduction, the more the restored tooth will flex. We definitely don’t want the tooth to flex since that potentially results in cracked porcelain. In their paper, they show that even a small fraction of remaining enamel will substantially stiffen the restoration compared to total enamel removal. With roughly 1 mm of facial enamel available on a typical incisor, that means a typical prep for pressed ceramic would remove all the enamel. By contrast, about half the enamel need be removed for a feldspathic veneer. So it makes a lot of sense to conserve some enamel for reasons of strength, never mind the other obvious advantages of being in enamel.
Note also their last statement, concerning strength. Hence, I do not provide night guards for reason of preventing fracture of the veneers since the veneered teeth should be “similar to natural teeth”. .
Revolutionary try-in system
For the reasons mentioned above and as many of you know, I have historically avoided the use of try-in pastes. Instead I have used the real composite for try-in. This procedure limits the try-in time and sometimes does not allow enough time for the patient to “buy the shade”. It seems like every time I hear about a total veneer debond (I have had none, that’s zero!!), there is some try-in paste issue to blame.
Well, Danville’s innovation to the rescue! Danville just introduced a revolutionary try-in composite, called Accolade PV Try-in. Since it is a composite, it matches the Accolade PV veneer bonding composite. The difference is that the Try-in version has drastically reduced amounts of light sensitive catalysts whereas the bonding composite has the customary amount of catalyst. After try-in, the Accolade PV Try-in composite need not be completely removed. It will polymerize when it comes in contact with the fully catalyzed Accolade PV composite. Awesome!! No more glycerin contamination issues. No more off color try-ins. Plenty of try-in time.
The Accolade PV shades were developed in consultation with Dr. Tom Hughes. Dr. Hughes is one of America’s greatest cosmetic dentists. Many of you know Tom from the Smile after Smile albums. (They are now sold by Smart Practice.) Tom found, as I confirmed, that only 3 shades of composite will suffice for dialing-in most feldspathic veneers. (These shades are Translucent, Light, and Extra Light.) Yours truly designed the two “darkening” shades, Yellow and Brown, which are not used as often as the other 3 shades but sure are handy when you need them. It is most interesting to note that DaVinci lab (famous for great feldspathic veneers) has a veneer bonding kit with nearly the same shades. They call theirs Bright, Brighter, Brightest and finally Ludicrous Bright. The equivalent ludicrous shade is also in the Accolade PV kit, called White Opaquer, a shade that I think would not be used by itself. It was designed as a blending shade and for pre-impression “block-out” of heavy tetracycline cases.
You can purchase the Accolade PV kit from any Danville dealer. One dealer which has it in stock is Tin Man Dental, (800) 554-6394. (www.TinManDental.com)
The new veneer plan and cooperating labs
So here is the new veneer plan: Specify to the lab the final shade desired, the prep shade (often Ivoclar/Vivadent’s “Die Stumpf” guide is handy for this one) and provide quality impressions. That is all they will need. I know four labs that have agreed, upon request, to simulate try-in at the lab with Accolade PV Try-in on a tooth colored prep replica, and inform you of the shade of Accolade PV to use. That is the biggest simplification ever in doing veneers!! The four labs are Denton in Southern California (877) 356-2317, Cardinal in Northern California (800) 443-6444, Andreou-ADL in upstate New York (888) 285-4110 and Lord’s in Wisconsin (800) 821-0859. I bet that many other labs will follow this procedure now that we have a great try-in composite.
The shade taking and lab try-in procedures are illustrated below.
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| Die Stumpf shade next to PV prep. | Veneers on model, 2 shades of Accolade PV Try-in |
References
1.Calamia JR, Etched Porcelain Facial Veneers, NYJ Dentistry 1983; 53:255-259.
2. Fracture load and mode of failure of ceramic veneers with different preparations. Castelnuevo et al, J Pros Dent 2000;83:171-180. (reprinted in Feb 2004 California Dental Assn Journal, pages 167-177.)
3. Magne P and Douglas W, Cumulative effects of successive restorative procedures on anterior crown flexure: intact vs. veneered incisors, Quint Inter. 2000,31:5-
Contact Wedge.
Here is another innovation, this one patented by Dr. Tom Hughes. It is the “elastowedge”, actually trade named Contact Wedge by Danville. The wedge is a very stretchable wedge that is placed with a rubber dam type forcep. When released, it enlarges in the mesial-distal direction. It thereby adapts the matrix against the tooth, even into a concavity if one is present, something a conventional wedge can’t do.
The elastowedge will not separate teeth. Tooth separation relies on using the Contact Ring or a similar device such as Palodent or Garrison rings. Danville is producing a dedicated forcep that will allow easy placement of the elastowedge. Forcep production is expected to be completed in late February. Danville dealers can supply the elastowedge right now. While awaiting the dedicated forcep, it is usable on a rubber dam forcep with some difficulty.
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| .Stretch with a rubber dam forcep. | Adapting matrix against the tooth. | Place ring above or behind wedge. |
Prelude Link
As many of you know, SE Bond (Kuraray) is the gold standard in bonds. The big challenge is from Prelude SE. What makes Prelude more interesting than SE Bond is that Prelude is compatible with all composites, whether light-cure, self-cure or dual-cure. SE Bond is strictly for light cures. Prelude is used just like SE Bond for light cure applications. However Prelude includes a product called “Link”, which may be used as a third layer to convert the Prelude to dual cure. Link also works very well with SE Bond.
I am making the following recommendation in the seminars. If you have been using Clearfil SE Bond, it is very likely that you are highly successful. It makes no sense to change. Just add Link to your armamentarium and use it with SE Bond when you want to place a dual-cured composite like Starfill 2B (Danville), Luxacore (Zenith/DMG) or Core Paste (DenMat) or Rock Core (Danville).
If you don’t now use SE Bond, you would be well advised to start using Prelude. The performance of SE Bond and Prelude is comparable. Prelude is less expensive. SE has a longer track record. Tin Man sells all these materials; that would be a good place to get good technical advice (800) 554-6394.
Bonding: Is simpler Better?
My good friend, Dr. Gordon Christensen recently said “Total etch is dead”. He is advocating use of self-etching primers rather than separate etching. I fully agree but we need to be especially careful of which self-etching material we select. All self-etching primers are not created equal!
There are two main strategies for self-etching primers. There are two-layer (what I call EP + B) and the all-in-one (EPB) materials. (The E refers to etch, P to prime, and B to bond.) Two subgroups of the EPB’s are mix (two component) and no-mix (just one bottle). I have not found a no-mix EPB that performs well enough to make it acceptable to me. The leading mix type EPB products are One-Up Bond F (Tokuyama) and Prompt L-Pop (ESPE, 3M). These are good performers. However, as with all EPB products, they have an inherent problem called “transudation”. This transudation is permeation of pulpal fluids through the hybridized bonding zone in the tooth. Transudation is through “water trees” in the hybrid zone. These water trees are created by the water that is contained in the self-etching primer. Without a second water-free Bond layer, transudation occurs. With the second “B” layer of the EP+B bonding agents, no transudation is seen. On the cover page are pictures of vital teeth covered with EPB and EP+B bonds. The EPB example exhibits transudation but the EP+B does not. Obviously the seal is in question when there is transudation.
Additionally, with the EPB’s, the strength of the bonding agent to composite interface is time dependent. If light curing is delayed after placement of the composite, strength will suffer. Pulpal fluid pushes the composite off the tooth. This is a current seminar topic and way beyond what I can write up in detail here. I will expand this section on the web site www.adhesion.com for those who can’t attend my seminars.
So the “short answer” recommendation is to stay with the EP+B products. If you want self-etching, my recommendations are SE Bond (Kuraray) or Prelude (Danville). Consider adding Prelude Link (Danville) to make stocking a separate bonding agent for dual-cure applications unnecessary.
From the current seminar handout, my latest veneer bonding recommendations:
Porcelain Veneer speed-bonding
This is a specific procedure which utilizes Accolade PV’s unique Try-in composite (patent pending). To obtain the absolute maximum try-in time, use the directions that are in the Accolade PV kit. In those directions, no light curable bond is placed on the silane. Instead only Accolade PV Try-in is used and then later mostly removed by mixing with Prelude #2. That procedure is excellent but I choose to use my Clearfil Photo Bond routine here, due to its long track record and dual-cure, but I do sacrifice some try-in time.
1. Before trying in the veneer, apply a silane [Rely X (3M), S-Bond (Danville)] to the uncontaminated, fluoride etched veneer. Follow the silane manufacturer's instructions (sometimes an acid wash is necessary with the particular silane but not with 3M or Danville, a great convenience). Next, coat the silaned veneer with an unfilled, light curing, “enamel- bonding" resin [Enamel Bond (3M), Visar Seal (DenMat), or E-Bond (Danville)]. Don't cure. Avoid dual cured resins, especially Photo Bond, for this step in substitution for the light cured one since they may cause premature composite setting problems. The silane is now "locked in" by the unfilled resin and is permanently attached, unless dissolved in solvents such as alcohol.
2. Try the resin coated porcelain veneers for fit both individually and in adjacent groups on the unetched teeth. The unfilled resin protects the silane from contamination. After try-in, just brush off the resin with a dry brush, if contaminated, and brush on fresh resin. (In extreme cases, ultrasonically clean the veneer in ethyl alcohol and begin again with the silane step.)
3. Choose the desired shade of Accolade PV Try-in composite and place on inside of veneer to check shade on unetched tooth. [If you are not using Accolade PV, you will need to follow the manufacturers directions for try-in paste, especially noting how it is removed after try-in.]
I usually try-in Accolade PV Try-in “Translucent” shade first; it is acceptable about 90% of the time. If the color needs to be modified, remove the veneer. Just wipe off the first try-in composite with a clean brush and change to the new shade. Try-in again. I find that when the first try-in does not produce an acceptable shade, slight white opaquing is usually needed (the tooth shows too much). Accolade PV has two excellent pre-opaqued whitish "veneer shades", Light and Extra Light, which greatly simplify this procedure. They usually eliminate the need for a custom mix. One of these two shades nearly always produces an acceptable try-in when the Translucent does not. In the rare event that the veneer needs darkening, just use a dark shade of flowable composite or the Accolade Brown or Yellow shades, or perhaps a blend of these. In addition to the 5 PV shades, Accolade PV has a White Opaquer shade that is intended for custom blending. It is the “super white and opaque” blending shade used at Danville to produce Light and Extra Light PV shades. Especially to be avoided for veneers are relatively high viscosity composite resins. They require excessive pressure to seat the veneers (veneer cracking problems), easily tear and form bubbles (black staining problems later).
4. Isolate, when necessary, with retraction cord [Ultradent #0 cord preferred], immersed in Visine if necessary for hemostasis. (Visine will not form a black sulfide stain at the margin like Astringident and other ferrous sulfates do.)
5. Clean try-in resin off the enamel surfaces, using pumice in a rubber cup. Avoid gingival contact to prevent bleeding. A Kincheloe “Retract” instrument (Danville or Tin Man) is a handy way to protect and retract the gingival tissue. Rinse with water and dry with oil-free air.
6. Brush at least 50% or Accolade PV Try-in composite off veneers and replace with the fully catalyzed Accolade PV. Complete removal is not required.
7. Isolate teeth to be veneered with interproximal strips to protect adjacent teeth (not being veneered) from the etchant.
8. See next step if using a self-etching system such as SE Bond. Otherwise etch tooth, wash and dry (assuming Photo Bond is being used).
9. Place one coat of Photo Bond on the etched tooth and air thin. If the prep is all or mostly all dentin and the veneer is fully light curable, then you may use self-etching SE Prime, then SE Bond, rather than etch and Photo Bond. Also Prelude SE works well. Note that with SE Bond, everything must be cured at once; no pre-curing of the SE Bond is permitted since it thickness would preclude proper veneer adaptation to the tooth. Prelude SE, being much thinner, may be light cured in advance of placing the veneer if care is taken to prevent pooling (air thin before curing).
10. Remove matrix strips prior to placing veneers on teeth. This step assures complete and passive seating of the veneers, even in multiples.
11. Gently place the veneers on the tooth, preferably all at the same time, and tack in center with small curing light perpendicular to facial surface, avoiding the margins. (The 3 mm diameter Demetron tip is ideal and takes 2-3 sec to spot cure.) After tack has fully cured, cure the other margins for about 1-2 seconds. Remove the resulting "jello" using a curette. Slide a metal matrix band mesial and distal of one tooth at a time and cure. The metal bands should be placed at the mesial and distal contacts of each tooth individually, preventing difficulty due to additive thickness of more than two bands at a time. To be avoided is placing a matrix prior to placing the veneer on the tooth. Pressure from the matrix will push on the veneer, forcing compensating seating pressure which results in broken veneers. If absolutely necessary, plumber’s teflon tape makes a good matrix.
12. Cure the entire veneer fully (slowly at first) with the matrix bands removed. Avoid high intensity lights such as PAC lights unless you desire the look of "characterized", cracked veneers.
13. Finish gingival margin resin flash with a "new" twelve fluted carbide bur (usually a 7901), if necessary, and finish interproximal with G-C New Metal strips, 600 grit (GC Dental). For the gingival margin areas, Danville’s Stainbuster (Flashbuster) also works very well to remove any excess composite with no risk of damage to the veneer.
14. Polish exposed margins using thin, flexible polishing discs. Diamond medium grit "Flexis" disks (Vident) work well when it is necessary to trim or reshape the porcelain. Use rubber porcelain polishing cups/points such as Brasseler's "Dialite" cup and wheel to polish the porcelain.
Issue 26, Spring 2005 Prelude, the latest in self-etching primers
Dear Fellow Bondodontists,
Fifth Quarter Seminars experienced a great surge of attendance in 2004. Thanks for your strong support. I attribute this surge to the inclusion of ozone in the seminars. Ozone will be the next revolution in restorative dentistry. Quintessence Publishing just published the book: "Ozone: The Revolution in Dentistry" edited by Prof. Edward Lynch. The book covers all research and clinical applications of KaVo's Healozone. For ozone info, you might also wish to see www.the-o-zone.cc
We plan to reduce my USA speaking for the remainder of the year, instead sponsoring speakers who I personally wish to hear. In September we will proudly present Dr. Geoff Knight from Australia, one of my favorite discussion partners. The seminars are at Ko Olina, Oahu, Hawaii on September 15 and North Lake Tahoe, California on September 24. Geoff may well have invented a clinical technique that obsoletes ozone!! If you wish to look at the background, search Saforide on the Internet. Saforide turns teeth black in the process of arresting caries. Geoff has found a way to overcome the color problem but maintain the effectiveness. Geoff does not speak much in the USA so don't miss this opportunity. To further entice you, we have arranged some super low room rates at the JW Marroitt Ko Olina Hotel and Spa, a world-class property. This is on Oahu, easy to reach from Honolulu airport but seemingly worlds away from Honolulu. At Tahoe, we will be at Northshore, near the California-Nevada state line in Kings Beach. A favorite hotel nearby is the Cal-Neva Lodge. Tahoe is at its best in September.
In November, we will be in Yosemite. We feature guest speaker Dr. Van Thompson, one of the top materials experts in the world. Van is very adept at transferring research to clinical practice. Last November we had an absolutely spectacular Yosemite seminar. Yosemite was at its very best with the first fall rain the day before. Weather is a bit hit and miss at this time of year but we seem to hit a lot more than we miss. Again we have negotiated great room rates for both the Ahwahnee Hotel and the Lodge.
There is a terrific program being planned for South Africa on August 11-13. It is being organized by Dr. Julian Holmes in a location very near Capetown. This is a great time of year for game parks (no water, no malaria) and the whales are along shore at Hermanus (so close you can hear them breathing). I will be a speaker at this one. For further info, please e-mail Julian: julianholmes@mweb.co.za
On October 21-22, Dr. Dan Laizure and I are doing an over-the-shoulder/hands-on course in his superb CARE facility in Walla Walla, Washington. This program will feature application of the "Kois deprogrammer" for establishing new occlusion. For further info, please see www.center4excellence.org. At this time we are planning some very "civilized" social events in the local wine country as part of the event.
Have a great 2005.
Sincerely,
Raymond L. Bertolotti DDS, PhD
Danville has just introduced Prelude, a unique self-etching primer. It bonds well to both cut and non-cut enamel, a feature which elevates it above many competitors. Of course it bonds very well to dentin. Prelude was independently tested by Larry Watanabe at UCSF. Larry found it to have bond strength among the best and perhaps more important, the lowest standard deviation of any bond he has tested. This result suggests technique sensitivity is low.
When used in light cure applications, Prelude is used very much like Kuraray SE Bond. Unlike SE Bond's incompatibility with self-curing composites, the compatibility issue has been solved by addition of a self-cure bonding Link that is supplied with Prelude. Time will tell if Prelude takes a share of SE Bond's market.
"Free is good", right? Well Prelude is essentially free for the first kit but there is a catch. Danville gives a voucher in the amount of the Prelude cost that can be used toward purchase of any other Danville product. Danville direct (800-827-7940) or presumably any Danville dealer will make this offer, which is valid to the end of March. There is a double whammy here. Prelude costs a lot less than SE Bond.
Many of you have heard my lectures where I mention the outstanding research of Dr. Franklin Tay in Hong Kong. Franklin has discovered what he terms "transudation", that is the permeation of dental fluids through the "sealed" tooth on vital dentin. Franklin's research has tremendous clinical implications, many of which I am covering in current seminars. It explains why a time delay after bonding and before curing composite leads to bonding problems when using the "all in one" (what I call "EPB": etch-prime-bond) adhesives. It also suggests why self-cured composites would be expected to have a compatibility problem with EPB adhesives. The water free, hydrophobic second layer of two-step bonds provides an effective water barrier to prevent the transudation from reaching the dentin surface. Based on this research, my bottom line recommendation is to stay with the two layer adhesives such as SE Bond or perhaps Prelude.
The above discussion is in harmony with a very extensive European study just published: A Clinical Review of the Durability of Adhesion to Tooth Tissue: Methods and Results, J. DeMunck et al., J Dent Res 84(2) 118-132, 2005. I quote: "Any kind of simplification in the clinical application procedure results in loss of bonding effectiveness. Only the two-step self-etch adhesives approach the gold standard and do have some additional clinical benefits such as ease of manipulation and reduced technique-sensitivity." I further quote: " The strong one-step adhesive, Prompt-L-Pop, performed very poorly, with a retention rate of 65% after 1 year in contrast to the "mild" two-step self-etch adhesive, Clearfil SE Bond, that exhibited excellent results up to 2 years".
Clinical experience continues to prove the ozone-initiated caries reversal concept.Quintessence Publishing just released the book: "Ozone: The Revolution in Dentistry" edited by Prof. Edward Lynch. The book covers all research and clinical applications of Healozone. For the latest ozone updates, see www.the-o-zone.cc
Introduction of Healozone in the USA is expected early next year. In anticipation of its release, I am continuing to cover the latest findings on ozone in the seminars. Here is the abstract of what may be the most significant clinical application paper to date, dealing with ozone effects on primary root carious lesions (PRCL's). The author, Julian Holmes, was our speaker for the sold-out Yosemite seminar last November. Note that 100% success with caries reversal was achieved at the end of the 18 month period.
Clinical reversal of root caries using ozone, double-blind, randomized, controlled 18-month trial. Holmes, J. Gerodontology 2003;20(2):106-14. A total of 89 subjects, each with two leathery PRCL's, were recruited. The two lesions in each subject were randomly assigned for treatment with ozone or air, in a double-blind design, in a general dental practice. Subjects were recalled at three, six, 12 and 18 months. Lesions were clinically recorded at each visit as soft, leathery or hard, scored with a validated root caries severity index. RESULTS: There were no observed adverse events. After three months, in the ozone-treated group, 61 PRCL's (69%) had become hard and none had deteriorated, whilst in the control group, four PRCL's (4%) had become worse (p<0.01). At the six-month recall, in the ozone group, seven PRCL's (8%) remained leathery, the remaining 82 (92%) PRCL's had become hard, whilst in the control group, 10 PRCL's had become worse (11%) and one had become hard (p<0.01). At 12 and 18 months, 87 Subjects attended. In the ozone group at 12 months, two PRCL's remained leathery, compared to 85 (98%) that had hardened, whilst in the control group 21 (24%) of the PRCL's had progressed from leathery to soft, i.e. became worse, 65 PRCL's (75%) were still leathery, and one remained hard (p<0.01). At 18 months, 87 (100%) of ozone-treated PRCL's had arrested, whilst in the control group, 32 lesions (37%) of the PRCL's had worsened from leathery to soft (p<0.01), 54 (62%) PRCL's remained leathery and only one of the control PRCL's had reversed.
Remember Danville's original Microprime, the formula based on HEMA and glutaraldehyde? It is now being reintroduced as Microprime G. The comparable product is Gluma Desensitizer (Heraeus Kulzer) which costs more than twice as much for a bottle half the size!
The newer Microprime formula that has been used very successfully for years is now called Microprime B. (It is designated B type because it is covered by my patent.) It contains HEMA and a proprietary disinfectant.
Both products seem to work well. Since there is good evidence that the active ingredient in preventing sensitivity is the HEMA, the B formula seemed more desirable since it does not contain tissue-burning glutaraldehyde. However some opinion leaders believe that inclusion of glutaraldehyde is preferable. So now there is a choice. Same low cost.
Many of you know my favorite anterior composite, Palfique Estelite. This is a spherically filled composite with the strength of a hybrid, the polish of a microfill and terrific handling. It is the most chameleon composite known so only few shades are necessary. While Palfique has for years received my very highest recommendation, many have asked why Reality has not rated it highly? (I am a Reality evaluator.) I think it's because many Reality evaluators tend to be influenced by availability of a wide range of shades, never mind if they are necessary or not.
Well, Palfique just got even better. If is now sufficiently radiopaque for posterior use. Low radiopacity was a limitation in the older material. There are a lot of new shades, Reality might even take notice! The new version is known as Palfique Sigma. This is truly a universal composite. I think Palfique Sigma is all you need besides a flowable composite. (I use Starflow and Palfique for posterior composites.) Once you try it, you are likely to clean out your refrigerator.
I should note that the translucency of Palfique tends to result in a "grayout" for large class III and Class IV fillings. That is why they also offer "opaque" shades such as OA2, that is opaque A2. It is not really very opaque, just enough to block out the gray translucency problem. I like the opaque shades OA1 and OA2, used by themselves, for direct resin veneers. Tin Man can tell you the shades their regular customers prefer (800-554-6394). That would be a good starting point for your initial order.
Yes, it's a deadly African snake and also my nickname for a new impression material that is deadly accurate and will wrap your margins. Think about margin reading. Is light or dark best for readability? I vote for dark. What is the darkest color? Black. So how about a black colored, thixotropic, fast setting "wash" viscosity? It's Danville First Half Light, designed to compete with the set time of Discus Half Time, a fine product but not black. First Half is about 30 seconds slower than the First Quarter series. Both work well in the Hoos/Morita H&H technique. They also work well in a more conventional dual-viscosity technique. The First Quarter series are the world's fastest VPS materials available in a complete range of viscosities. I think Danville's "regular set" Star VPS materials should be called Overtime. I am constantly amazed that these relatively slow setting, industry-standard materials sell at all. Once you get used to the fast set, there is no going back, not even to Star VPS.
I just heard a great lecture from Gordon Christensen at the Atlanta AGD meeting. It sure is good to see Gordon back lecturing after a two year absence (for church service). In his lecture he presented the results of a CRA study on strength of composite buildups retained by various posts. Gordon said he changed his mind about posts after seeing the results. What CRA found was that composite/fiber posts such as Luscent Anchor, Snowpost, and FiberKor post made core buildups about as strong as a traditional stainless steel post. (Gordon showed Snowpost to be the most radiopaque of the these three fiber posts.) Amazingly, these fiber posts produced cores even stronger than those made with titanium posts. However Gordon's deciding factor was not strength, rather it was the mode of failure: root fracture for the metal posts and crown dislodgement for the fiber posts. Gordon says that metal is obsolete, not just for fracture mode reasons but also for reasons of root darkening from the metal. I fully agree. The CRA Newsletter has a nice write up on posts in the May 2004 issue. Customer service at Danville has extra copies (800-827-7940). Snowlight, the light transmitting version of Snowpost, got the highest overall grade in the CRA study.
One of my favorite lab technicians, Laura Kelly Brown, is now running for Vice President of AACD. I have known Laura for a long time. She is a world-class technician, AACD Accredited. I can't imagine a more dedicated and hard working candidate for this job. She has served on 19 committees and 6 years of AACD Board work. Please join me in supporting Laura Kelly Brown for VP.
Most of you have heard me mention Reality, the best and most complete source of clinical info on techniques and materials for esthetic dentistry. From its start in the 1980's, Reality has progressed to an annual book resembling a Sears and Sawbucks catalog in size. Much of the research reported is from the Reality Research Lab. In addition to the annual book, there is a monthly newsletter. I am proud to be on the editorial team, in the company of some the world's most astute and influential dentists. If you don't know Reality, consider becoming a member. See www.realityesthitics.com for more about Reality and for membership information.
One of the most popular e-mail questions lately has been about color correction and bonding of veneers. I think flowable composite is ideal for bonding of veneers. Flowable rather that thick composite allows me to feel the veneers seat completely and prevents cracking the veneers from excess seating pressure. Most veneer "kits" make shade selection far to complex. For veneers, flowable composite needs to be available in about 3 specific shades. One veneer kit offers over 20 shades, that's crazy! Some manufacturers make their shades all too opaque, thereby reducing the vital look of teeth. Tom Hughes and I helped Danville dial-in the 3 necessary veneer shades for the clinic; these are sold as standard shades in the Starflow PV and Accodade PV kits. Fortunately Tom and I both have the benefit of experience in placing thousands of porcelain veneers, "keeping it simple".
If the veneer is too thick to allow light curing, then the bonding resin color will not be a factor because it can't show through. In that case, Panavia F in the TC ("tooth colored") shade works well. If there is only enamel on the tooth side, you may omit use of the ED Primer and just etch the enamel with phosphoric acid. Panavia F bonds well to etched enamel. Use silane on the HF etched veneer. Panavia F bonds well to silane. If there is dentin, use of the self-etching ED Primer without separate etching is wise. Panavia F is dual curing so you need not worry about incomplete cures. (The new Panavia F 2.0 will cure with any type of light, a problem with Panavia F, which would not cure with a typical LED light.)
Now, let's say it's a typical thin feldspathic porcelain veneer, about 0.5 mm thick, that you want to bond. Clearly the bonding composite will influence the final shade by showing through the thin veneer. Panavia F does not have a sufficient shade selection for color correction. Here is how I proceed to try-in for color, using StarFlow PV or Accolade PV (Starflow is thinner, Accolade is thicker), both "flowable" composites:
I usually try-in with Translucent shade first; it is acceptable about 90% of the time. If the color needs to be modified, remove the veneer, wipe off the first composite with a clean brush and change to the new shade. I find that when the first try-in with Translucent composite does not produce an acceptable shade, slight white opaquing is the most often needed change (the tooth shows too much). You may blend in color modifiers such as Danville VP White Opaque, Bisco Tints and Belle de St Chair HP Opaker. However Starflow PV and Accolade PV kits have excellent pre-opaqued whitish "veneer shades", Light and Extra Light, which greatly simplify this procedure. They eliminate the need for a custom mix. One of these two shades nearly always produces an acceptable try-in when the Translucent does not. In the rare event that the veneer needs darkening, just use a dark shade of any flowable composite. (I often select A5 Starflow.) In addition to the three PV shades that Tom Hughes and I like, Danville also has a White Opaquer in both Starflow PV and Accolade PV that is intended only for custom blending. It is the intense white blending shade that Danville uses to mix with the Translucent shade to produce pre-mixed Light and Extra Light PV shades. These shades are definitely worthy of a try, very highly recommended.
My seminar topic of porcelain crown try-in has emerged as one of the most popular seminar short topics. The concept is to put a protective layer of Clearfil Photo Bond mixed with Clearfil Porcelain Bond Activator (a specialized silane) on the crown prior to try-in. This 3 drop mixture of A and B Photo Bond plus Activator bonds well to porcelain and to metal while protecting the internal porcelain and metal from contamination. After try-in, the crown is just washed with tap water and dried. The Photo Bond mix is hydrophobic and not displaced. Then the bonding resin such as Panavia F is placed in the crown and bonded to the tooth as usual. Photo Bond and Panavia F are both dual curing so there is no concern about lack of sufficient light cure.
Regardless of its being available for nearly 20 years, the Clearfil Porcelain Bond Activator system is a well kept secret for porcelain bonding. It does not depend on the use of hydrofluoric acid to etch the porcelain. There is a nice paper by Llobel et al. that found the Clearfil system equaled the best silane bond on hydrofluoric etched porcelain (Fatigue span of porcelain repair systems, Int J Pros 1992;5:205-213.). Clearfil is the ideal material for intraoral porcelain repairs, no HF needed!
I just read yet another porcelain repair paper that neglected Clearfil while discussing how difficult it is to repair porcelain adjacent to enamel (Bonding to Enamel/Dentin Etched with Phosphoric and Hydrofluoric Acids, PPAD 2004;16(9):653-659). With Clearfil, it is simple to bond adjacent porcelain and enamel. Just sandblast, etch all with phosphoric acid (etches enamel, cleans porcelain), wash, dry, apply the Clearfil 3 drop mix. You just bonded both surfaces (and also any metal and dentin, should they be there too.) Now you may place any brand of composite. It is worth noting that Reality gave only the Clearfil porcelain repair kit a 5 star rating, definitely deserved.
Issue 25, New Year 2004, Ozone Therapy
Dear Fellow Bondodontists,
It has been a whole year since I printed the last newsletter edition. In 2003, Mary and I did a lot of international travel, cutting our domestic schedule for the last half of the year. The Bondodontics seminar even went to China with the first "fee for service" dental seminar.
2004 will be exciting. I will be introducing ozone treatment for reversal of caries (see inside). This may very well be the biggest change in bondodontic thinking since total etch. If you would like a preview, go to http://www.the-o-zone.cc/
For 2004, we have arranged some of the very finest guest speakers to share the programs with me. The first one, Gary Unterbrink, will be speaking in June at Tahoe and Hawaii. When it comes to bondodontics, I rate Gary "the best of the best". As many of you know, a lot of the recent concepts I have presented have come from Gary. He does not speak in the USA very much, so my very best advice is "don't miss" this opportunity. Besides, the venues are great.
The other exciting development is possibly returning to Yosemite. After 20 successful years, we pulled out last year due to a group-unfriendly management policy. We know that a lot of you have been disappointed. Now they have invited us back with what we hope will be more acceptable arrangements. It looks like either the first or second weekend in November will be scheduled. The dates are pending due to unresolved invitations to some world-class guest speakers.
There will be some seminars in the UK again in 2004. The 2004 dates are February 20 in Manchester and February 21 in London. Right now, there are $361 roundtrip airfares available from San Francisco to London; my E-fare was booked with United at www.ual.com. Also there is a May series in Australia, one of our favorite travel destinations.
In this issue, besides the usual news items, I am printing selected questions I received.
Have a great 2004.
Sincerely,
Raymond L. Bertolotti DDS, PhD
In 2004, I will be introducing the HealOzone (CurOzone USA). Although manufactured in the USA, it is not yet approved for sale in the USA (FDA approval is pending). It is approved in Canada (Scican, Toronto) as well as most of Europe (KaVo Germany) . Ozone treatment has been shown to clinically reverse caries in a very large percentage of cases (results vary from 86% to 100% success in various studies).
The ozone delivery system is a device that takes in air and produces ozone gas. The ozone is then delivered via a hose into a disposable sterile cup at a concentration of 2,100ppm ± 10%. The ozone gas is refreshed in this disposable cup at a rate of 615 cc/minute changing the volume of gas inside the cup over 300 times every second. The cup forms a seal around the lesion being treated so that ozone cannot leak into the oral cavity.
Around 20-40 seconds of ozone application have been shown to penetrate through carious dentin to eliminate any live bacteria, fungi, and viral contamination. This treatment eliminates the ecological niche of cariogenic organisms as well as priming the tissues for remineralization. The remineralized tooth structure is more resistant to future decay than was the original. In fact no healed areas have been observed to form recurrent caries!
Here is the CurOzone generator and the intraoral delivery system:
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I foresee applications to several major restorative problems:
Surely other applications will follow.
Some recent E-mail questions:
I routinely use Panavia to bond ceramic based crowns (e.g., Procera, Inceram), without silane. I am faced with a patient who reacts to Panavia. What is the nature of the bond to ceramic and what do I look for in choosing another material to bond to it?
Unfortunately all-ceramic crowns are strongest when bonded. Panavia is a wise choice and you are correct in avoiding silane on the aluminum oxide. Panavia's adhesion monomer bonds directly to the aluminum oxide. (Silane use is a common error. A good reference is: Bonding of glass infiltrated alumina ceramic: Adhesive methods and their durability. Kern M and Thompson VP, J Pros Dent 1995;73:240-249.) So to avoid resin (which presumably causes the patient reaction), I suggest switching to Captek or even better, Graham electroplate, with ceramic. These are super esthetic and can be conventionally cemented with resin-free cements.
I have gotten into the habit of using only Starflow for more and more of my posterior fillings. Where are its limitations?
While I personally see no problem here and occasionally do so myself, Danville does not officially recommend it since they have no wear data studies. I have heard many favorable user reports. Staflow strength compares to Herculite. The filler particles are very similar in size. Wear is known to be controlled by filler size (not percentage fill) so for both strength and wear, I predict success. (Starflow, in a CRA evaluation, was the strongest flowable composite tested and not significantly different in strength from Herculite, the strongest conventional composite tested. )
I have been using Clearfil SE Bond for some time with better success after your advice to not air dry the 2nd coat, but I am finding that I am getting incidents of sensitivity with it, more so than when using the etch/ Microprime/ Photobond technique. Any reason why?
Other than air-drying problems, the only thing that comes to mind is insufficient light curing.
Have you checked your light output? I would want at least 600 on the meter for a 10 second cure. The Photo Bond is dual curing so light curing it dosen't matter as much. I know a lot of docs who continue to use the Photo Bond technique you mention, especially now that Starfill 2B is available in an auto-mix cartridge. The 2B is the ideal first increment in that technique.
Should I purchase Panavia F or Panavia 21, advantages and disadvantages?
Make it Panavia F. The F version can be light cured without use of Oxyguard whereas 21 needs Oxyguard on all margins since it will not light cure. The F version need not be light cured so you have the option of using it just like 21 with the Oxyguard. As I understand it, soon there will be another version of Panavia F, which will light cure with LED lights, a problem right now (except for the LED 5, see below).
I need a new light. Should it be an LED? If so, which one?
There seems to be tremendous interest in LED curing lights these days. That is understandable: quiet, small, and a nifty look. The problem is that some adhesives and composites lacking the commonly used camphorquinone photo initiator will not cure with most LED lights (example: Panavia F). However Ultradent has taken the lead in introducing a LED light (the Lume 5) that cures all known composites and bonds. Ultradent added some separate diodes to take care of the spectrum problem. This is not a cordless light but I certainly prefer a corded light over a cordless one that does not cure everything. The Lume 5 has a sort of hand piece shape and fits nicely into many hand piece holders. Ultradent has some useful accessory tips that are worth looking over. They come with the light.
Can I try-in with Panavia F to verify color?
Yes, fortunately that is quite easy. Just use the B-paste alone. It will not cure without being mixed with the A paste. After try-in, I remove the Panavia F with ethyl alcohol in an ultrasonic cleaner. Note that the A paste has a neutral, almost translucent color so that its addition to the B paste has a negligible effect on the try-in color
After hearing about a debonded cantilever bridge in the lateral incisor position, the type I have taught for many years, I inquired about the lab work. Here is the response:
I checked with the lab they use Rexillium, acid etch and sandblast. I etched with 37 percent phosphoric gel then I used ED Primer (as I write this I seem to get a flashback to your course about a strong acid followed by a week one), the cement (Panavia 21) stayed on the tooth.
Rexillium is a good choice. The Panavia bond to the Rexillium should be about twice as strong as to the enamel. The Panavia stayed on the tooth so there is something terribly wrong with the Rexillium surface. You say "Rexillium, acid etch", if that is electrolytic acid etch in the lab, that is a major lab error. The electrolytic etching removes the "bonding" metals from the alloy. (Such etching was done in the old days, before Panavia, to mechanically retain composites such as Comspan.) The best treatment is just sandblast chairside, after try-in, then place Panavia directly on the sandblasted metal. It is wise to sandblast chairside rather than in a lab, since Danville research, done many years ago, showed a bond strength decrease with time after sandblasting. As you correctly recall, often a strong acid followed by a weak acid makes the weak acid ineffective as an etchant (example: hydrochloric as used in PREMA "microabrasion", then phosphoric). However concerning the specific combination, phosphoric etchant on tooth and then ED Primer, no harm. The enamel bond strength is actually improved compared to just using ED Primer and the Panavia setting is speeded up (see data in recent seminar notes, reprinted below). Presumably the enamel was well etched by the phosphoric acid before the ED Primer was applied.
| Panavia / ED Primer Bonds | |||
| Etchant | Enamel | Dentin | Set Time |
| ED only | 24 MPa | 12 MPa | 60 sec. |
| Etch Only | 30 MPa | n/a | 240 sec. |
| Etch + ED | 30 MPa | 11 MPa | 60 sec. |
Danville has introduced a new flowable composite, Accolade, to supplement Starflow. They have different flow characteristics. While Starflow is a very high flow composite, Accolade is a sort of "no slump" flowable with sufficient flow to wet bonded surfaces.
Along with Accolade's customary Vita shades, Danville has developed a new porcelain veneer bonding system, Accolade PV. The PV designation on Accolade PV refers to porcelain veneer shades dialed-in by yours truly, as opposed to the usual range of Vita shades of Accolade. I think most veneer bonding systems are far too complicated. I only need 3 or 4 shades of the veneer bonding composite, beginning with Translucent and then 2 or 3 more opaque whitish shades. That is exactly what is offered in Accolade PV. In the very unlikely event that I need to darken veneers, a dark Vita shade of any flowable composite would work.
Here is what a top cosmetic dentist, Dr. Tom Hughes, said about the new Accolade PV:
I have now seated 12 PV's with Accolade PV. It has the perfect viscosity to feel the veneers go to place, yet it does not slump, tacks in and cures easily. Clean up is easy and fast. Accolade PV is perhaps the easiest material I have ever used for seating PV's. BTW...I am almost out of the Extra Light shade. Can I get some more material? I'm sort of spoiled now. Accolade has wonderful Light and Extra Light shades and a very nice White Opaque. Most of my veneers are seated with Translucent or Light/Extra Light materials. I have never used a shade darker than A-1 or A-2 for delivering veneers, so I really can't comment on the darker shades from any manufacturers. Thanks again for letting me field test a great product.
Danville is in the process of developing non-setting try-in pastes due to market demand.
Personally I will not use them. I find that I can try in with Accolade PV and have plenty of time to evaluate color. The try-in pastes only introduce the possibility of contamination, something I want to avoid.
Before the try-in, I prime the clean, HF etched veneer with silane and then an unfilled resin (supplied with Accolade PV kits), then place Accolade PV on the primed veneer and try-in. After a satisfactory try in, I remove the Accolade PV with a clean brush and replace it with fresh material. I pumice off the tooth with a fairly dry pumice/water mixture then etch. After 20 years experience with porcelain veneers, I can assure you that this procedure works. It save lots of time compared to removing try-in pastes and avoids the possibility of contamination by non-setting try-in materials.
My favorite bond for porcelain veneers continues to be Clearfil Photo Bond. I receive frequent E-mails from docs having problems with other bonds and when I switch them over to Photo Bond and Accolade PV or Starflow PV, the problems invariably disappear. Enough said!
I continue to recommend "feldspathic" veneers rather than the pressed ceramic veneers. Quite frankly, I think many labs and lecturers recommending pressed ceramic veneers are just commercially driven. The word feldspathic seems to cause confusion; I am referring to the "brush on" porcelains that are baked either on platinum foil or on refractory modeling material.
Example porcelains are Ceramco 2, Finesse, d-Sign and Noritake. Historically, many of these porcelains were based on a mineral called feldspar. In my opinion, pressed ceramics should be avoided for veneers. They require too much tooth reduction and never look quite as good as fine feldspathic veneers. Most of my veneers are about 0.5 mm thick. Since thin veneers are a subject of widespread interest, I am putting veneers back into the 2004 programs. I will not be covering veneer basics since it's so well understood. Instead I will show how to successfully complete a tetracycline case with feldspathic veneers, just over 0.5 mm thick (obviously no anesthesia was required since the veneers are in enamel).
Make a good impression!
My last newsletter (please see issue 24 at www.adhesion.com if you missed it) detailed the H and H impression technique. It certainly has revolutionized my impression taking. While it is preferable to hear me or Jeff Hoos (the inventor) lecture on the topic before attempting it, many of you have reported success from just reading. A friend in Oregon comments:
Ray, H and H works so well that I can't understand why everyone is not using it!
Now there is another technique that seems even more ideal than H and H if you do not need to force impression material subgingivaly. This technique eliminates the need for the tricky die spacing required for the H and H impressions. The technique is not new, it is the familiar dual viscosity technique but involves two new impression materials dialed-in by yours truly. I use the same closed bite tray as I use in H and H. (I get my trays from Tin Man (800) 554-6394).
The dialed-in impression materials are Danville's First Half, Light and Heavy. The Light has an innovative black color, to contrast with everything. The color makes margin reading the best ever. The Heavy is rather high in viscosity, forcing the hydrophilic Light into all areas (but not subgingival as well as does H and H). The set time of First Half is about 30 seconds longer than for Danville's First Quarter. The extra time makes the dual viscosity technique very easy.
There is another Danville impression material system worth mentioning for its uniqueness. The system was made to the clinical specifications of Dr. John Kois. He wanted a super "runny" light body and an ultra high viscosity heavy tray material. The materials that resulted are called Star VPS Ultralight and Ultraheavy. As in the two above techniques, the heavy body pushes the light body material. Dr. Kois usually uses retraction string and his proprietary hemostatic agent to expose the margins for the runny material. Since the working time and set time is a lot longer than for the other materials mentioned, the Ultraheavy can be higher in viscosity than permitted for faster setting materials. It takes extra time to dispense heavy bodied materials. The Ultralight is at the technical limit of low viscosity. I don't know of a more runny material. I compared it to a popular brand labeled "XLV", presumably meaning xtra low viscosity; well, it wasn't even close. If you want runny, Danville's Ultralight is it!
Regarding impression putty, it is not used very much in America but perhaps it should be. Putty is a lot cheaper than the syringe delivered materials. I like Danville's putty because it does not stick to my Travenol latex gloves when I mix it. Additionally the glove powder does not seem to affect its set. My technique is classic putty/wash where the putty is pre-polymerized.
Dear Fellow Bondodontists,
Wow, time flies when you are having fun! It has been a year since I printed the last newsletter edition. In 2002, Mary and I did a lot of international travel, both for our seminars and to obtain current information for those seminars. The international demand for "bondodontics" lectures has been quite astonishing. So here is the next newsletter issue, a bit later than I intended. Hopefully it will serve as an update as well as an indicator of your currency in the concepts I am teaching.
I do not seem to be slowing down any in my schedule, contrary to previous plans. We are very proud to continue bringing you guest lecturers who are among the best in the world, the ones I personally want to hear. The next one will be at Yosemite, featuring Dr. David Winkler from London, one of Europe's best. Sadly this will be our last Yosemite seminar; the new Yosemite Concession Company is not group friendly and has become unreasonable in their reservation policies.
We have also announced our third Alaska cruise, this one departing Vancouver (a great destination in itself) on June 1 and arriving at Seward, just south of Anchorage, a week later. (Marie Cameron, our travel agent for many years, has secured some very good cruise rates. She can be reached for cruise information at (510) 276-1190.) Besides many excellent stops, we cruise Hubbard Glacier, the ship captain's favorite. This cruise features guest speakers Tom Orent (the Gems Guy) and Tom Hughes (famous for those smile books). The seminar will be a blend of esthetic dentistry and marketing of that dentistry.
Our schedule this year will be a one day format. This one day format on Contemporary Bondodontics is my favorite and is getting excellent reviews. Note the very civilized venues, like Santa Fe and Darwin. Also to be noted is the guest program at Tahoe with John Kanca and yours truly, a sort of "battle of the bonds". That is on June 21 and should be a great one.
Have a great year.
Sincerely,
Ray
I am grateful to Jeff Hoos of Connecticut for telling me about this technique. Jeff is a "must hear" for his daylong program, which includes a remarkable story on how he discovered the H&H technique. H&H stands for hydraulic and hydrophobic. You use hydraulics to push a hydrophobic impression material. The hydrophobic material is a polyvinyl siloxaine (VPS) capable of displacing blood and saliva. When done properly, there is no need for retraction string (nor for some overpriced and under performing syringable clay). H&H seems to be very atraumatic to the gingival tissues. Jeff helped develop J Morita's PerfectimTM VPS materials for this technique; likewise I helped dial-in Danville's materials for the technique. What I wanted was a blazing fast set, a very hard "moose-like VPS", a thixotropic character to the wash (non-runny but very easily movable, sort of like whipped cream), and a very dark color for easy margin reading. So what we have are two very capable but different systems; it might be a good idea to try both. (Tin Man sells both, (800) 554-6394. They even have the appropriate Danville materials assembled into a custom H&H "trial kit" and they can also supply suitable and inexpensive trays.) The tray "moose" needs to be quite hard; Danville's StarTM VPS Stiff Bite is the hardest I have seen. Actually the hardness is more properly described by the Shore A Durometer measurement. The Shore A Durometer instrument consists of a blunt-pointed indenter attached by a lever to a scale that is graduated from 0 to 100 units. A reading of 0 indicates the indenter has completely penetrated the sample; a reading of 100 units indicates no penetration has occurred. Danville's Stiff Bite has a value about 91, quite impressive by industry comparison. Likewise the wash should have a low durometer reading in addition to the above-mentioned handling properties. If you want to use other than Danville or J Morita materials, check that the durometer reading is above about 88 for the moose, below 40 for the wash. The more the difference, at least in theory, the better. In my estimation, all VPS materials are sufficiently hydrophobic to repel the fluids, even those labeled "super hydrophilic".
Here is the technique but don't even think of using it without informing your lab. The lab must use die spacing as is described below, otherwise you will have crowns that are too tight to seat and you will be among the 20% of naysayers. They should also be informed about the best method to record the occlusion provided by the closed bite impression (see below).
The H&H (hydraulic and hydrophobic) technique:Stiff Bite VPS is injected onto a plastic rimless tray (Fig 1). ). Blood is displaced so there is no need to wash it off. The patient closes into the Stiff Bite VPS, which forms a "peripherally sealed custom tray" around the prep area. (I use the rimless plastic trays like Dentamerica's to deliver the impression material to the mouth.) After the Stiff Bite sets, the patient opens while your fingers retain the impression on the opposing arch (Fig 2). It is important that the tray remain in the mouth, not yet removed. Removal and re-seating is prone to re-seating errors. The impression surface is spray washed and dried while in the mouth. Using an auto mix tip, First Quarter Light VPS is syringed onto the Stiff Bite VPS in the prep areas and adjacent areas (Fig 3). There is no need to syringe Light VPS directly onto the teeth; that procedure tends to trap bubbles. The patient closes fully and forcefully, thereby exerting hydraulic force on the Light impression material. The Light flows and follows the path of least resistance, first flowing subgingivally since the periphery is sealed by the Stiff Bite. Typically the Light flows even past the margins (Fig 4). The excess then flows out the periphery. Again, blood is displaced form the teeth so there is no need to wash it off! It is ideal to hold your hand on the patient's chin and masseter muscle while the Light polymerizes to avoid patient movement. After the initial forceful closure, the closure need not be forceful but it must be steady. If you are using First Quarter Light, the patient can open in 1 min, 30 sec. You have the impression.
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| Fig 1 | Fig 2 | Fig 3 | Fig 4 |
Now a word of warning: There is a small percentage of dentists who simply can't get the H&H technique to work. There is a large percentage who say that it is the best and most accurate technique ever (I am in that group). Proper die spacing is the critical difference; you need about 40 microns in the area backed by the Stiff Bite, that is the supragingival areas. I presume that the Light wash elastically displaces the Stiff Bite and when the impression is removed from the mouth, an elastic rebound occurs to create an undersized die. In the subgingival margin areas, there seems to be no need for die spacing since presumably there is no significant elastic distortion in that area. Therefore the 40 microns of die spacer is used on the die in the areas corresponding to the Stiff Bite backing and away from the margins. J Morita's PerfectimTM removable die spacer seems ideal for this application. It can be removed from the die after the crown is completed and the margins of the restoration checked on the die.
Since I don't want die spacers applied to margin areas, I reserve H&H for subgingival margin impressions. (For supragingival margins, simultaneous use of First Quarter Monophase on the tray and First Quarter Light on the tooth, the Light dispensed thru Danville's exclusive needle on an automix tip, will give you the same blazing speed and accuracy.)
Some problems that lead to bad results are worth mentioning: not forming enough Stiff Bite around the prep (Stiff Bite must have rigidity to resist the elastic distortion of the Light wash); use of VPS putty (its durometer reading is too low) rather than Stiff Bite; and undetected patient movement during the closed bite. However, the most common problem is improper die spacing.
Now this may seem obvious but apparently not to at least one: never use Stiff Bite in a rigid metal tray; such a hard and stiff VPS can lock into undercuts! Also note that H&H is strictly a closed bite technique. Severe undercuts (such as a bridge) should be blocked out; I often use Surgident Periphery wax to accomplish the blockout.
Unfortunately dental labs often have problems dealing with closed bite impressions, whether or not they are taken with the H&H technique. A recent Quintessence paper reads: "Technician not keen on combined arch system", "required time consuming adjustments" , and "time-consuming technique" (Quintessence Inter 2001; 32:805-810). These comments signal a resistance to using an unfamiliar laboratory procedure. For this reason, I have posted complete lab instructions in the previous newsletter edition. See Newsletter, Issue 23, New Year 2002, below.
Use of flowable composite as a first increment has become an almost standard procedure. Hannu Laamanen and yours truly published the technique in 1999 (Quintessence Int 1999; 30:419-422). We found that flowable composite adapts to the preparation far better than condensable composites, a "sure-fail" proposition. I prefer to use a low viscosity, "runny", flowable composite such as Starflow or Tetric Flow for the first increment of composite. (Starflow is stronger, Tetric Flow is more radiopaque.) Low viscosity helps assure a well-adapted first increment. It is known that all composites "shrink toward the best bonded surface". If the only bonded surface is the gingival margin, it's obvious what the composite shrinks toward (Fig 5). Many lecturers have expressed concern that flowable composites shrink too much compared to conventional composites. This is only half of the pertinent story. The other half is elastic modulus, usually ignored. Basically what should concern us is the stress placed on the composite to tooth interface as a result of polymerization shrinkage. Stress is determined by the shrinkage multiplied by the elastic modulus, known as Hooke's Law. Fortunately with flowable composite the elastic modulus goes down as the shrinkage percentage goes up, about equalizing the bond stresses for conventional and flowable composites. In other words, increased polymerization shrinkage is irrelevant to interface integrity! Now let's consider a real problem encountered in use of low viscosity flowables, bubbles.
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| Fig 5 |
Bubbles in a flowable composite primarily result from air originating in the needle tip. Air in the needle can "float" on the composite if the syringe is placed horizontally. Think of what happens when a bottle of wine turned on its side. The solution is to push out the air (Fig 6) before allowing it to float in the syringe. Storing the syringes vertically is a further safeguard to prevent the air from entering the syringe (Fig 7). (Thanks to Tom Hughes, our guest speaker on the Cruise, for that idea. )
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| Fig 6 | Fig 7 |
While there are many methods and materials that can be used for bonded post and core, here is my most frequently used procedure. This is a popular topic in the seminars these days.
It is my belief that the post should have a tapered cross section to gradually dissipate stress. Additionally a taper prevents the hydraulic forces that can result from blunt-end posts inserted into viscous resin, causing root blowouts. I want the radiopacity to be as high as possible (Fig 8). I want the elastic bending to mimic that of dentin but the lengthwise stiffness to be greater than dentin. In other words, I want it to bend but not stretch. There should be no stress raising notches or slots. These properties best describe Carbotech's Snowpost, a pre-silanated, zirconia-silica fiber post (Fig 9). It is marketed by Danville in the USA and Canada. In Fig 8, Snowpost is shown in the center along with two competition posts. Note the blunt end on the post to the left and low radiopacity in the tapered post to the right.
The dedicated Snowpost reamers are slightly oversized so the reamer, marked with a silicone endo ring for length, can be the "try-in post", preventing contamination of the actual Snowpost's silanated surface. Here is the procedure based on using Snowpost.
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| Fig 8 | Fig 9 |
Loose fitting post
Tight fitting post
Now proceed to build the core as in step 8 above.
Further helpful hintsTempting as it seems for its tremendous bond strength, use extreme caution in selecting SE Bond for use in canals since it is a light cure only and you can not light cure it well in the canal. Even if you can light cure it, it is NOT compatible with self-cure core pastes (contrary to what CRA says, in my opinion.) SE is compatible with light curing Photo Core, so you may use SE Bond if you are positive that light will fully penetrate the Photo Core to reach all of the SE Bond. It is NOT sufficient to cure the SE Bond before you place the Photo Core, light must penetrate all the way to the SE Bond through the Photo Core. (The explanation, too long to print here, is in the current seminars.) There is some interesting research in Italy that shows Photo Core in a canal can be cured by light curing down a light transmitting post. If you want to try that technique, Danville's SnowLIGHT post would be a logical choice. SnowLIGHT has an epoxy bonder rather than Snowposts' composite. Otherwise the posts are similar.
One problem with Clearfil bonds, my favorites, is that they all adhere to metal matrix bands, making their removal difficult. Don't even think about burnishing the band or worse, sandblasting the band surface. If you do you will have created a new class of stainless steel reinforced composite! Thankfully there is a new tool to greatly facilitate matrix removal: the MegaGrip forcep (Fig 10). It sure makes the competitive products look and feel wimpy! MegaGrip can be ordered from any Danville dealer such as Tin Man (800) 554-6394.
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| Fig 10 |
Think Adhesion!
The following case nicely illustrates what adhesion can do to conserve tooth structure. I calculate that retention from 1 mm2 of bonded surface is equivalent to about 3-4 mm of cemented crown ferrule. Recognizing the potential of adhesion, this case was restored with zero invasion, I utilized pure adhesion to restore vertical dimension. The lab marking of the margins on the casts are shown below (fig 11).
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| Fig 11 | Fig 12 | Fig 13 |
The vertical dimension was first tested with a hard splint (Fig 12). Gold was bonded to the 2nd molars, the rest were restored with feldspathic porcelain on the anteriors and IPS Empress on the posteriors (Figs 13, 14 and 15). Excellent esthetics in the anterior region was achieved with minimally invasive preps (Fig 16 and 17).
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| Fig 14 | Fig 15 | Fig 16 | Fig 17 |
We have learned that incompletely seated restorations are the sole cause of bite pressure sensitivity. I will quote Gary Unterbrink (our last guest speaker): "If the prep has retention form, it is probably wrong!" What Gary is talking about is the potential space created under a restoration when it does not fully seat. It is clear that creating a prep without retention form would help preclude incomplete seating. The composite bonding agent shrinks during polymerization, bringing the restoration closer to the tooth, rather than creating an internal gap.
DIAGNOdent false positivesSpecial thanks to Dennis Mihalka for this tip. Apparently certain green prophy pastes such as Nupro can cause a DIAGNOdent reading. I will quote Dennis: " One can smear the finest film (not seen with human eye) on a paper tray cover and it will still read very high. If by chance Nupro mint is used, I do not even bother to use the DIAGNOdent. It will cause you to believe cavities exist and will waste an appointment or worse, waste a virgin tooth."
Suspecting problems related to products with green color, I looked at Caries Finder G (green) and to learn exactly what a trace of the green does to the DIAGNOdent readings. Even when it was washed off both healthy enamel and dentin, I got false positive DIAGNOdent readings. This needs some further investigation so for now, be cautious in using DIAGNOdent and any green colored dental product.
Dear Fellow Bondodontists,
Last year, 2001, was a year most of us would prefer to erase, at least in part. On Sept 11 Mary and I were in Perth, Western Australia, about to begin a seminar. When I reached outside our hotel room door to get the morning paper, I was greeted with headlines "America at War". Somehow we managed to do the seminar but I can tell you positively that the Aussies were as shocked as we were and all of us were quite distracted that day. A week later it was quite heartwarming to see flowers lining the steps of the American Consulate offices in Sydney, Australia.
We had actually planned a sabbatical time last fall, perhaps a fortuitous move. Our seminars were well attended and well received last year. We noted remarkable numbers of new attendees joining our "regulars". It sure is nice to be able to tell the newbies that they can seek reassurance from one of the regulars that the concepts taught do in fact work as stated. Several of our regulars mentioned, after missing a couple of years, how far behind they felt. Those comments gave me the idea to print here some of the seminar handout pages so that you can determine if you are current. I selected the day 1 series on posterior composite and from day 2, a new series on lab use of closed bite impressions. The wet field, even blood wet, stringless, H & H impression technique was a big hit this year. This is a concept taught to me by Jeff Hoos of Connecticut. The lab procedure given optimizes this technique. You can get the details of H&H at www.dentalexplorations.com, Jeff's web site.
Mary and I are increasingly booking seminar venues that are in very "civilized" locations. For example, New Zealand in May. New Zealand is one of our favorite places and quite a bargain these days due to the favorable exchange rate. (Mary, can we afford to go home?) Even the airfares to New Zealand are quite reasonable. There are two Hawaii venues in July, one in Princeville on Kauai and one in an almost secret bit of paradise, Ko Olina, near Honolulu. Both are world-class properties. The room rate we negotiated at Ko Olina is the best deal I have seen in a long time.
Also at Yosemite, one of our most popular venues, on November 7-9 we are very proud to present Dr. Gary Unterbrink of Austria. Gary is back by popular demand. He will be covering indirect restorations following his superb presentation on direct resins two years ago. If there ever was a guy who can think outside the box and back it up with science, this in the guy. Absolutely tops. Don't miss it. These Yosemite seminars attract many of the best dentists we know. It's a great place to relax and meet some of your finest colleagues, mostly top Bondodontists. Yosemite is great in all seasons (except perhaps in summer when it is too busy). We have a very civilized schedule, Thursday and Friday afternoons and Saturday morning. I suppose that is why we sometimes sell out as far as 6 months in advance!
Let's all look forward to a super 2002.
Sincerely,
Raymond L. Bertolotti DDS, PhD
Here is the current procedure for posterior composites, using the "bite-formed" technique. This is in the Day 1 seminar. At the end, there is a quiz to test your knowledge.
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Test your understanding of the above:
While the above procedure works beautifully if you follow it cookbook style, here are a few questions (Q) to test your true knowledge. These answers (A) would be part of a typical program. (Answers follow questions, at end).
A1. Air thinning tends to over-thin the SE Bond on the occlusal while not removing puddles deep in the prep. The overthinning reduces bond strength and the pooling leads to radiolucency.
A2. Starfill 2B works fine so long as you thoroughly cure through it to get light to the SE Bond. If you anticipate not being able to get light through the 2B, my recommendation is to abandon SE Bond and switch to the dual-curing version, known as Liner Bond 2V. Another possibility is to switch to total etch followed by MicroPrime and then dual-curing Photo Bond prior to the 2B.
A3. Sometimes not at all. If the matrix is closed at the gingival and you plan to use a low viscosity flowable composite, there is no need to wedge since Danville (as well as Palodent, but not the 3M/Garrison and Hawe-Neos) rings provide more than sufficient tooth separating forces.
A4. The apex is down so as to avoid disturbing the contour of the Contact Matrix. Remember that the Contact Ring separates the tooth, the wedge only serves to close the gingival margin. A large gutta-percha point will often close an open matrix without disturbing a contact.
The dual-arch impression technique is documented to work well. A recent paper reviews previous literature as well as validates a new impression material.1
In my estimation, the real problem with utilization of the dual-arch technique is the laboratory treatment of the impression. Indeed the