Something I Learned in Dental School That CEREC Has Totally Destroyed

Dental school can bring back scary memories and even some good memories (for me it was mainly positive). I remember taking everything I heard or learned as gospel. But then came private practice, dealing with patient expectations, and the pressures of being your own business.

Specifically, I recall being taught in dental school that you should always wait after a root canal before you make a crown. You wanted to make sure that the tooth ‘didn’t blow up’ before making a crown. It made sense, especially given the type of endodontics i was performing at that stage of my life!

It made total sense. And why shouldn’t it have? The technology and techniques didn’t exist to have it not make sense. When you were hand filing with a .02 taper stainless steel file and doing lateral condensation your endo could likely blow up. Then on top of that you place Cavit that leaks like crazy. Then we had to have the crown made and the lab bill associated with that crown. You should wait!

But there is something really terrible about that concept that I didn’t really understand. First, root canals ‘fail’ due to leakage and reinfection. That can occur from poor endo technique not cleaning out the canal system. Also from apical leakage, but more importantly from coronal leakage.

It’s the coronal leakage that is the real concern. Let’s just assume we do a good job on the endo and the apical seal. Then what do most of us do – we place a leaking temporary filling material on the tooth and pray the patient comes back to finish the crown.

And most dentists making crowns today do so with a laboratory (nothing wrong with that by the way). That means there is a time with a leaking provisional. This is simply crazy.

My suggestion is that we should be performing the entire procedure in a single visit. And the entire procedure is properly fixing the tooth. That involves both the endodontics and the final restoration.

Let’s take a look at a case example.

Patient presented with extensive decay

Patient presented with extensive decay

Radiograph showing extent of decay and proximity to pulp

Radiograph showing extent of decay and proximity to pulp

Initial preparation started with occlusal depth reduction

Initial preparation started with occlusal depth reduction

Rough prep completed and decay extended into pulp

Rough prep completed and decay extended into pulp

Rubber dam isolation and sealed using light cure opaldam

Rubber dam isolation and sealed using light cure opaldam

endo completed and fiber post placed to help retain the buildup

endo completed and fiber post placed to help retain the buildup

preparation completed

preparation completed

Final design in polychromatic block

Final design in polychromatic block

Restoration milled and directly tried in mouth to evaluate fit

Restoration milled and directly tried in mouth to evaluate fit

Restoration single step stain and glaze

Restoration single step stain and glaze

final restoration being bonded into place

final restoration being bonded into place

immediate delivery post op photograph showing well blended restoration

immediate delivery post op photograph showing well blended restoration

Looking back… Very very very very (that’s a lot of very’s for emphasis) few of my root canals ‘blew up’ that made me thankful for waiting before doing the crown. In fact, I would venture to gather that my root canal success has gone up thanks to sealing with a crown at time of endodontic therapy.

And the great news as a CEREC owner – if the tooth does blow up and I need to remake the crown, I can do it quickly and economically because I can just hit remill!

This type of case is a perfect example of being patient centric. What was once three visits (at a minimum) – 1. root canal, 2. preparation and temp, 3. restoration delivery – is now converted into a single 1.5 to 2 hour treatment.

2016-01-17T09:45:36+00:00

About the Author:

Dr. Tarun Agarwal represents the next generation of leadership for the dental profession. As a respected speaker, author and opinion leader, he is changing the way general dentists practice. His common sense approach to business, dedication to clinical excellence, integration of technology and down to earth demeanor has made him a recognized educator.

12 Comments

  1. Andres Powditch del Rio September 16, 2014 at 8:50 am - Reply

    SIRONA Ortophos XG 3Dscan……SIRONA heliodent xray…….SIRONA ENDO for mechanical endo sealing……SIRONA T2line super torque rotational instruments…..SIRONA CEREC Omnicam+MCXL…….same consistent results always in max 2 hours of coordinated work flow….love it….great pictures, great results…..love your “about the author” feel very identified with it….saludos from Chile.

  2. gerald September 16, 2014 at 9:09 pm - Reply

    That’s great except that the tooth did not NEED a crown…Something else that they taught you in dental school that was wrong.

    • Tarun Agarwal, DDS September 17, 2014 at 6:25 am - Reply

      Gerald good to see you reading and commenting. While we disagree on many fronts regarding the uses and role of direct composite in dental practice, I respect your opinion and invite some more clarity and feedback from you on this. Always willing to listen and learn.

    • Tarun Agarwal September 18, 2014 at 5:22 am - Reply

      gerald… good to see you here! you and i have disagreed many times in the past when it comes to direct composites.

      i would love to hear your more ideal conservative method of treating endodontic teeth.

      • Terry G Box DDS MAGD September 18, 2014 at 5:18 pm - Reply

        I’m going to jump in here as well. I probably would have crowned this tooth with a bonded EMAX because it appears on the preop to have considerable weakness of the buccal and lingual walls. I do , however have many endodontically treated bicuspid and anterior teeth that have very small restorations, or only an access restorations, that are restored with direct bonded composite and have been doing well for years. Each case must be considered on its own merit regarding available sound tooth structure, function, position in the mouth, etc. I almost always recommend a crown as soon as possible (or now immediately) following endodontic treatment on molars and multi-rooted bicuspids. 1st Bis are notorious for splitting. A restoration has to be able to do more than fill a hole. It must help prevent further destruction of the tooth. Bonded composites restore strength, compared to amalgams. Covering the cusps of teeth help prevent fractures. Decisions, decisions….

    • Andres September 18, 2014 at 7:50 am - Reply

      You may be right in that it not NEED a crowne….the issue (when having a fluid comunication with your patient that today participate activelly as very informed persobs) is that they are treatments with better prognosis in time…..its MUCH more probable that the posted crowned bicuspid will survive longer that the direct dammed resin.
      Give patients good consisted information (that they too have) and then decide what to do as a “final” restoration.
      Both paths may have the job done…..the tricky question we are sommited to is when they ask you…..but Doc, money is not an issue…..whats going to last longer ?????

      • gerald September 18, 2014 at 5:42 pm - Reply

        Andres;
        The worst possible thing that you can do for a tooth is to place a crown on it. Teeth will never be stronger than when they have all their enamel. When we strip away all of the enamel in a young patient what we are really doing is pre-implant treatment planning. The majority of crowns (cemented,non-bonded) begin to fail in the 20-25 yr range of usage. In many patients, removing the crown reveals little to no natural tooth structure and requires the extraction of the tooth.
        Would it not be better, from a patient standpoint to incrementally replace a missing part of a tooth until the patient is in their late 50s when a crown will be placed that will retain the tooth the the remainder of the patient’s life?
        The best restoration is the restoration that keeps the most amount of natural tooth structure. PERIOD.

  3. gerald September 18, 2014 at 7:01 am - Reply

    Hi Tarun;
    The overwhelming majority of teeth do not need an indirect restoration for survivability. Every endodontically treated molar requires the protection of an indirect restoration.
    We may have disagreed about resins but I have almost 25 years in placing posterior resins as does Paul Belvedere. We know what works. Teeth are not fragile as demonstrated by the MODBL 40 year old amalgams.
    Most teeth don’t need crowns but most dentist’s production does.

  4. Terry G Box September 18, 2014 at 11:03 am - Reply

    Tarun, Very nice demonstration of the advantages of CEREC. You are so right about permanently sealing the canal at the time of completing endodontic treatment, even if it is not done with the final restoration. I have always completed at least the core build up on completion of endodontic treatment. When I infrequently refer to the endodontist for treatment, I request that they complete the core build up on completion as well. Studies( don’t ask me to quote,please) have shown that a two week exposure of the access of a completed root canal leads to a high rate of failure.I went back to my alma mater, Baylor, in 1978 after a short time in practice for an endo course and recall a discussion I had with the department head, Dr Pat Ferillo Sr., about canal sealers. Sargenti was being hotly debated back then and I asked him his opinion of it. He told me that as long as the canal was thoroughly cleaned and disinfected and the access was permanently sealed , on a non suppurative tooth, that he didn’t care if you put “sterile bird shit” , or nothing, in the canal as long as the access was permanently sealed.

    • Tarun Agarwal September 18, 2014 at 4:45 pm - Reply

      terry…. i totally agree… when my patients go to endodontist i insist on a bonded buildup… seal the tooth….

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