Avoiding Restorative Failure

Lee Ann Brady, DMD


In our practice, one thing that we are extremely proud of is our commitment to the quality of care that is provided for our patients. I often meet dentists from all over the world who share the same goals of providing the best quality technical dentistry, and creating happy and appreciative patients. The challenge is the shadow side of this, how it affects us when we provide a technical solution that doesn’t work, or interact with patients who aren’t happy and appreciative. Most of us set the bar fairly high and are pretty tough on ourselves (and others) when the results fall short of that mark. It’s telling that the term we use to define this circumstance is failure.

It has been more than 25 years since graduation from dental school, and if I listed the challenges I have encountered practicing dentistry, dealing with failure would be at the top of the list. I’ve experienced many nights when I lie awake at 2 am and cannot go back to sleep because of an upset patient that day, or because I saw a crown that I did with a visibly open margin in a radiograph taken in a recall exam. In the early years, it didn’t take much to create pretty significant angst and have me weighing the number of “great” days in practice against the number of “bad” days. There are many ways to manage this stress, but manage it we must to continue practicing over an extended period of years.
The first way I chose to manage it was to escape from the practice of dentistry, not necessarily an approach I strongly recommend to others, but one many dentists consider or fantasize about. Its amazing when I share my story of how I left the practice of dentistry for 3 years, how many dentists approach me afterward and share that they are seriously considering it, or have thought about during their careers. Once I came back into dentistry, I decided to proactively practice differently. And part of that was finding a way to deal with failure; it’s that approach that I will share with you in the rest of this article.

Figure 1. Lips at rest pre-op. Figure 2. Full-smile pre-op.
Figure 3. Retracted teeth together pre-op. Figure 4. Retracted teeth apart pre-op.

The place I started was by defining or getting clear on what failure meant. We could go to the dictionary and look it up, but what is most important is to come up with a personal/professional definition. I looked at both what the word means to me (personally), and what it means as it relates to who I am (professionally). Simply stated, the definition of failure is when the actual outcome does not match the expectation.
In the practice of dentistry, there are several sets of expectations we manage: our own, the team’s, and the patients’. My expectations have changed dramatically over the years. In the beginning, I held a belief deep inside that if I was really good at what I did, technically and as a communicator, I could treat a patient’s decay and he or she would never get another cavity. If you’re chuckling as you read this, it may be because it sounds familiar, and you can probably guess how well that worked out for me! If we step outside of the realm of dentistry and think about technology, do computers fail? I think we would all say yes, if they stop working in the first 6 months to 2 years that we own them. If you have a computer that is more than 2 years old, and you find out it can’t run new software you’d like to have, is that a failure? I’d guess most of us would say “no” and agree that the computer is simply “old technology.” How about a car, or an appliance? If we think about it, there is a difference between when they fail and when they are simply beyond their lifespan. The differences between failure and obsolescence are time and disappointment. Each of us has an understanding of how long a computer, car, or appliance will last, and if they stop working before that timespan has elapsed, we are upset. After that we simply accept it is time to repair or replace it. Throughout the years I have developed a bias that all dentistry also has a lifespan, and creating clear expectations about that timeframe is the key to minimizing the stress for ourselves, our team, and our patients.

The question we need to answer is, how long does the dentistry we provide last? If you asked your patients how long a crown lasts, what do you think they would answer? If you are thinking they would say some version of forever, you would be correct, based on my experience. When I first started becoming aware that the challenge was expectations, I started to ask patients what their understanding was around the lifespan of their restorations. I was amazed how many patients thought that once a tooth has a crown on it, it could no longer get a cavity and it never needed to be worked on again. What I came to understand is this comes about not because we tell them it will last forever, it’s because we don’t tell them the work delivered has a predictable lifespan. Patients look in their mouth and no longer see any of their tooth since it may be completely covered by the crown, so they assume nothing else can happen.
Before you can help patients understand how long they can expect their dentistry to last, you have to answer that question for yourself. The challenge is to get comfortable with the fact that the answer is highly variable, and we can never really know for any particular tooth or patient the “right” answer. Understanding the longevity of dental treatment for me is about weighing the technical risks of the procedure, the individual risks presented by this patient, and this tooth against the bell curve that represents the lifespan of that procedure, and taking my best guess.
When I am talking to a patient who needs a crown, I help him or her set realistic expectations. I say something like this: “So, many of my patients are curious about how long a crown will last. The truth is, there isn’t really an answer to that, but I’d like to help you get some idea of what you can expect. I have patients who have crowns replaced a year or 2 after we do them, and I have others who have crowns that are still working great after 2 decades. There are lots of reasons we might need to replace a crown, like the tooth gets a new cavity; some of those risks we can work together to minimize, and others neither of us have any control over.”
If patients I am speaking to have particular risk factors that affect the longevity of their restorative, I want to make those individual risks part of this conversation. When my team and I are clear and realistic about the longevity of the care that we provide, and are partnering with our patients to minimize their risks, the emotional energy around failure begins to evaporate. The next piece of the puzzle is creating clear expectations for patients and having ownership of treatment choice be theirs.

One of the things that is unique in dentistry is the variability of possible treatment plans. I believe that, with all of the information and records from a comprehensive examination, each of us should come to the same diagnosis. However, for that diagnosis, modern dentistry can offer a multitude of solutions. The treatment plan is a product of the dentist’s perspectives and the patient’s circumstances, objectives, and temperament. Throughout the years, I have become aware of the fact that we all treatment plan from our own paradigms and perspectives. We plan procedures in which we are confident more often than ones that we do not understand well. Furthermore, we plan the treatments we would chose for ourselves, more often than those that we would not do in our own mouths. As a result, in these and many more ways, our personal biases and perspectives creep into the treatment planning process. I strive to minimize my point of view in the treatment plans that I present to my patients as much as possible. This happens by following a structured planning process that makes me think through all of the possibilities (as best I know them) and having all treatment plans cocreated with a highly involved patient. I see my role as helping patients become fully versed in their present condition, the possibilities dentistry can offer them, and the risks and benefits of the options.

Figure 5. Upper occlusal pre-op. Figure 6. Lower occlusal pre-op.
Figure 7. Wax-up matrix to unprepped teeth. Figure 8. Initial prep to full-contour matrix.
Figure 9. Lips at rest provisionals. Figure 10. Full-smile provisionals.
Figure 11. Upper provisionals. Figure 12. Retracted teeth together provisionals.

The patient’s responsibility is to choose what is in his or her own best interest based on that information. The choices patients make are influenced by many factors that include finances, time, discomfort, predictability, convenience, and we could go on and on. I share the ways different treatment options vary in regards to these parameters as part of a risk/benefit analysis during planning. Once patients have all of the information they need, they will make a choice (Figures 1 to 6).

Take a moment and review the preoperative photos, then answer the question, “Is this an easy case, or a hard case?” When I present this at lectures, the usual response is some chuckling and squirming in seats. Finally, the answer that “this is a hard case” comes forward. If you were thinking the same thing, I’d ask you why is it a hard case? What makes it so difficult? There may be some technical challenges to the case; of course, these may vary for each of us based on our learning and experience levels. The challenging part of this case that is common to each of us is the concern of failure. If the patient was able to do this much damage to his or her teeth, what will happen to the restorations? This challenge in this case is what has so many of us sitting in continuing education courses studying about tooth wear and full mouth rehabilitation; we are looking to learn how to have this case not “fail.” From a technical perspective, one of the most challenging pieces of this case is the treatment plan. Having this case not fail is all about clarity around expectations, the patient’s and ours. This patient’s crowns will have a lifespan, as do everyone’s, but it will be shorter due to excessive risk from the forces he or she applies and teeth with fair to poor restorative situations. If both the patient and I are first clear about the risks and the impact that they have on the lifespan of the restorations; and if the patient has an understanding regarding the maintenance of the restorations and that they may look different than another person’s restorations; and if he or she chooses to proceed in having the dentistry done; then, we have minimized the greatest risk of failure.

Examination and Presenting Condition

A 60-year-old male presented to our office. He had suffered a lower spine injury in his 20s, leaving him with limited mobility in his lower limbs, and chronic pain and medical issues. He was on numerous medications, including narcotics to manage chronic pain. He was very interested in saving his natural teeth and in restoring both the aesthetics and function of his mouth, and was being seen regularly for hygiene.

Aesthetic Exam

  • Inadequate tooth display at rest
  • Reverse smile-line
  • Short anterior teeth due to wear
  • Unlevel occlusal planes
  • Buccal corridor discrepancy.

Occlusal Exam

  • Moderate to severe tooth wear
  • End-to-end anterior occlusion
  • Muscle stiffness and palpation response
  • Medial pole anterior disc displacement without reduction on left
  • Lateral pole disc displacement without reduction on right
  • Group function right and left
  • Crossover interferences on posterior teeth.

Dentition Exam

  • Severe wear: teeth Nos. 20 to 29; evidence of erosion
  • Severe wear: teeth Nos. 6 to 11; evidence of erosion
  • Teeth Nos. 21, 28, 5, and 12 missing from childhood orthodontic care
  • Tooth No. 14 missing; bridge teeth Nos. 13 to 15 with recurrent decay
  • Tooth No. 19; missing an old crown with inadequate tooth structure and recurrent decay.
  • Tooth No. 30; recurrent decay.

Perio Exam

  • Sulcus depths within normal limits
  • Minimal plaque and calculus
  • Localized areas of bleeding.

As part of the examination and diagnosis process, a risk assessment was completed in each of the areas so that the patient and I could review it. I want to assess my patients’ current risks, and what we can do together to minimize or manage any risks.
Aesthetic Risk—Low; patient had very reasonable expectations about the aesthetic results. He wanted a natural tooth color and appearance for his age. He wanted to eliminate all of the metal in his smile.

Figure 13. Protrusive end to end provisionals. Figure 14. Right excursive provisionals.
Figure 15. Right crossover provisionals. Figure 16. Full-smile final.
Figure 17. Retracted teeth together final. Figure 18. Retracted teeth apart final.
Figure 19. Left crossover final. Figure 20. Upper anterior final.

Functional Risk—High; had evidence of severe wear in combination with evidence of erosion. He presented with a history of acid reflux and 40 years of significant medications. It was challenging to ascertain the true occlusal risk without more information from either the use of an occlusal appliance or during the provisional phase.
Mechanical Risk—Teeth Nos. 19 and 30 had a high risk of failure due to previous endodontic treatment, minimal remaining natural tooth structure, and potential high muscular/occlusal forces.
Teeth Nos. 7 to 10 and 23 to 26 had minimal tooth structure remaining to restore, and presented with a moderate-to-high risk of restorative failure.
Bridge from teeth Nos. 13 to 15 presented with a moderate risk of mechanical failure.
Caries Risk—Using a CAMBRA assessment, his caries risk was high due to the existing cavities and history of caries, dry mouth, and significant medication induced xerostomia, previous restorations, and difficult areas to clean.
Perio Risk—Low; the patient presented with very good home care and regular hygiene visits.

Treatment Planning
The treatment plan was developed with the patient. We discussed his present condition and the options for restoring his mouth, and how to achieve the aesthetic and functional goals that he had shared with me at out first meeting. No removable options were presented to him, as he was very clear that he did not want dentures of any variety (including over-implants). As a part of this discussion, we went over the risk assessment and some things he could start doing immediately to reduce his risk factors.
The most challenging part of the planning process was how he wanted to manage the teeth that would be challenging to save due to the loss of tooth structure and prior restorations. He decided to try to save teeth Nos. 19 and 30 with traditional restorative techniques, saving implants for the future when these restorations succumbed. On the anterior teeth, he decided to place bonded restorations and not opt for endodontic therapy and post cores, understanding that we might encounter bond failures routinely, but knowing that the restorations could be recemented or remade. This was weighed against gaining retention with root canals and post placement, but the risk would have been loss of the tooth from root fracture, or significant recurrent decay around the post.

Treatment Sequence

  • Prepare upper arch and place provisional at new vertical dimension of occlusion (VDO)
  • Prepare lower arch and place provisionals at new VDO
  • Complete endodontic treatment on teeth Nos. 15 and 19
  • Finalize upper anterior restorations
  • Finalize lower anterior restorations
  • Finalize upper posterior restorations
  • Finalize lower posterior restorations
  • Fabricate and deliver nightguard.

Clinical Treatment
Treatment was started with 2 full-day appointments to allow the VDO to be opened and the teeth to be placed in provisional (Figures 7 to 15). This process allowed the patient to experience an initial positive change in his aesthetics and begin to test the new occlusal design. This also allowed us to gather more information about the functional risk. Upper and lower impressions were taken, along with a face-bow and centric relation bite record. The mounted models were sent to the dental laboratory team for completion of a diagnostic wax-up. Initial preps were completed using reduction matrices made from Flexitime Easy Putty (Heraeus Kulzer) to make sure we had adequate reduction, and to create a frame of reference for the final tooth shape and position. The maxillary arch was done on day one and teeth Nos. 2 and 3 were left in the original crowns to facilitate fabrication of the provisional and, in addition, as a reference to the upper occlusal plane.
The mandibular arch was provisionalized on day 2. With the provisional in place, we assessed phonetics and the patient’s ability to accommodate to the new VDO. The patient had endodontic therapy completed on teeth Nos. 15 and 9, which had been evaluated for retreatment during the provisional phase. The provisionals were left in place for 4 months to further evaluate function. Canine guidance with crossover support on the central incisors was created. The patient tolerated this very well, with little to no wear evident on the bis-acryl (Venus Temp 2 [Heraeus]) provisional in this time frame. We encountered little challenge with the provisional coming out, with the exception of the lower molar (tooth No. 19), which we knew was questionable in the area of tooth structure to hold a restoration. The decision was made to splint the crowns on teeth Nos. 18 to 20 to increase retention and in planning for a future implant on tooth No. 19 at the time that it fails.
Final restorations were phased in sections to make impressions and appointment lengths more manageable. The final restorations were made from lithium disilicate (IPS e.max [Ivoclar Vivadent]) (stain and glazed), with the exception of the upper 3-unit bridge, which was porcelain-pressed-to-metal and the lower 3 splinted units which were also porcelain-pressed-to-metal. Following delivery of the final restorations, an occlusal appliance was fabricated for the patient to wear during sleep every night. The patient maintains routine hygiene visits with the application of a chlorhexidine varnish (Cervitec Plus [Ivoclar Vivadent]) and brushes one time daily with Clinpro 5000 (3M ESPE) (Figures 16 to 20).

About one year after delivery of the final restorations, the patient came in with a loose tooth No. 30. The post had failed and the tooth had recurrent decay. The patient decided at this time to proceed with an extraction and the placement of an implant.
We rebonded tooth No. 24 at about 2 years after the crown was originally placed. No recurrent decay was present, and the restoration was simply cleaned out and bonded back in place.
Each time the patient came in for a recare visit, he did so with a full understanding of what had happened. When tooth No. 30 eventually failed, his reaction was, “Well, we knew this one was risky and I was the one who decided to try and hang on to it. Wish it had lasted longer, but I think I should go ahead with the implant.”

Was this case a success or a failure? In my opinion, and considering my personal/professional definition of failure, it has been a success.
Why? The technical challenges were understood from the outcome and the patient made his treatment choices based a thorough examination and diagnosis. In the end, this case represents a situation in which there was no mismatch between expectations and outcome due to solid doctor-patient communication.

Dr. Brady is a privately practicing dentist and nationally recognized educator and writer. She has worked in a variety of practice models from small fee-for-service offices to large insurance-dependent practices, as an associate and as a practice owner. From 2005 to 2008, Dr. Brady held the positions of resident faculty and clinical director for The Pankey Institute. In 2008, she moved to Scottsdale, Ariz, to join Dr. Frank Spear in the formation of Spear Education and the expansion of his curriculum. She served as executive vice president of clinical education until June 2011. As director of education and president of Lee Ann Brady, LLC, she launched her Web site, leeannbrady.com, offering clinical and practice content daily as well as innovative online and live education programs. She is the clinical editor for the Seattle Study Club Journal and a guest faculty member at The Pankey Institute. She can be reached at lee@leeannbrady.com.

Disclosure: Dr. Brady lectures for Ivoclar Vivadent, Heraeus Kulzer, and 3M ESPE.