Tooth Structure is Weak

2 Rating(s).

Posted on By Gerald Benjamin In Composite Resin

Ask any dentist and many will tell you that when part of a wall is missing, that the remaining tooth structure is weak even when there is a significant amount of supported (underlying) dentin.

A long time patient fractured the small remaining disto palatal cusp. That cusp, whether present or absent had no measurable effect on the remaining tooth strength and yet a large number of dentists would immediately remove ALL of the remaining enamel for a crown under the guise of strengthening the tooth.

I placed an MODL composite in the maxillary right first molar 20 years ago (prior to the time that I beveled all cavosurface margins.) Upon removal of the existing restoration, I learned that there had been no leakage down the walls or on the floor. The bond remained perfectly intact for 20 years.

I removed no additional tooth structure except to place a bevel and restored the tooth with another MODL bonded composite. Someone might place a crown on this tooth but it won't be me. I would expect this restoration to last 25 years.

(Aside: I recently saw 9 of my long term patients on the same day who have been my patient for 30-38 years. Every patient has every tooth that they had when they became my patient. As a group, they had very few crowns in their mouths which is WHY they still had all of their own natural tooth. To paraphrase my friend Maurice...One tooth for one lifetime.)

Natural tooth structure is much stronger than they taught us in dental school or that most practicing dentists believe.

Maxillary first molar with disto palatal cusp fractured off
Tooth had a 20 year old MODL bonded resin restoration that I had placed

Completed MODL completed bonded resin restoration
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It is amazing to see your long term results. Minimal invasive concept, patient and tooth friendly!
Have you used a cofferdam 20 years ago?
Best regards


Hi Snjezana; I have used a rubber dam since the first day that I was in clinic in dental school. I have never placed a posterior restoration without rubber dam. For the first 15 years of my career, I placed all of my amalgams with rubber dam. In 1992, with the introduction of dentinal bonding, I stopped placing amalgams and have only placed resins in posterior teeth. The overwhelming number of my original resins survive until today and the number of restorations that have failed and gone on to become crowns can literally be counted on one hand. It is my hope (unlikely) that ALL of my oldest resins will become crowns during my remaining years in practice. lol. Filtek Supreme which I have used for about 15 years is an amazing material. Prior to that I used Kerr Herculite and Ivoclar's Heliomolar. Regards, gerald


Great conservative work Dr.Gerald. You always inspire with your long term results of resin restorations. Regards.


Dear Dr. Gerald
Excellent mastery with composites. More important restoration lasting twenty to twenty five years. Commendable!
Just one query why not Tints/ Colors to highlight grooves and fissures as natural tooth (to mimmick nature)

Dr. Neeraj Mahajan


Hi Neeraj; Dentists enjoy playing with tints but no one but you and I would see it which makes US happy but adds nothing to the value. More importantly, my restorations are bulk filled, carved to ideal anatomy, contour and occlusion and cured using bilateral trans enamel illumination with two powerful lights and tinting while fun would make a complex technique more complex. Thanks for your kind words. Regards, Gerald


Gerald as always I enjoy seeing your conservative restorations.
Thanks for posting them.
Take care Brian Mills


Thank you so much, Brian!
I believe that the majority of crowns that dentists place are totally unnecessary AND are based on the rules of GV Black that were formulated (100 years ago) prior to dentinal bonding.
I quickly realized in 1992 that adhesive dentistry completely invalidate the rules for when to place a crown but sadly the majority of dentists continue to quote GV Black guidelines.
The average posterior direct bonded resin restoration survives for 7 years according to Gordon and thousands of my restorations placed with a rubber dam and with a meticulous attention to adhesive protocols have lasted 20+ years.

How can our profession have such a disconnect?


Gerald I completely agree that rubber dam and isolation are one of the keys to successful long lasting restorations.
Please keep posting cases. I really enjoy seeing them and hearing your thoughts about restoring complex cases with minimally invasive procedures.
Take care Brian


I couldn't agree more with the clinical approach, especially the way of thinking of Dr. Benjamin. The Key Factor of this case is the Longevity of the redtorations and the PRESERVATION of Natural Dental Tissus.
And the most important outcome is preventing further treatment like RCT, crowns or implants.
My only issue is the use of the Bulk filled technic especially if used with the self etch bonding, because according to Bart Van Merbeck it is a recipe of disaster.
The Tinting thing is a waist of time and add nothing.
Asking in the forum if Dr Benjamin uses the rubber dam is shocking!!
No one is intitle to call himslelf Dentist if he or she, don't use rubber dam in restorative dentistry or RCT.
Nassib Fares


Hi Nassib;
Thank you for your very strong endorsement.
I studied with Paul Belvedere, one of the fathers of resin dentistry in the mid 1990s and he was a very strong proponent of bulk fill. In my opinion, I will tell you that bilateral, trans enamel illumination using 2 powerful lights (Valo from Ultradent) simultaneously, will reduce the stress of curing away from the center and towards the bonded walls. The last cure is then from the occlusal.
What you must remember, I have been using this protocol for 20 years and we cannot question the clinical outcomes. In fact, I saw a patient yesterday that I placed an MODL for tooth #12 that has not only survived since 1991 but looks exactly as it did when I placed it. We cannot challenge each other about 'givens' because they have been proven, not by 'research' but by practical, everyday dentists who have followed their patients for DECADES.

As you mentioned,Nassib, conservative restorative dentistry greatly diminishes the likelihood that endodontics will be needed. In fact, only one or two teeth A YEAR require endodontic treatment in the year that I restore them...AMAZING!!!!!!

20 years ago I challenged the great John Kanca when he said that curing with an argon laser was the worst possible way to cure resin. I asked him at the annual AACD meeting in Puerto Rico what was going to happen to all the thousands of restorations that I had already cured with my argon laser? Would they debond? ...Silence.

After that I challenged John...and don't get me wrong...I have great respect for him as a dental leader (not so much his politics lol) and I said to him, "When your science does not match my clinical realities, you must change your science."