David J. Clark, DDS, defines patient-centered outcomes vs process outcomes and promotes a more minimally invasive mindset in the profession that favors preservation and restoration of the natural tooth.
Q: What are patient-centered outcomes?
A: Patient-centered outcomes are the treatment results that are important to patients. We may contrast this with process outcomes, which are the things clinicians do in an effort to affect the desired patient-centered outcome. An example of targeting process outcomes is when an endodontic retreatment is recommended because the obturation does not meet the standards of contemporary endodontic practice. For instance, there was a newsletter sent out by the American Association of Endodontists essentially advocating for the retreatment of root canal treatments simply because the canals looked underfilled in the radiographs. In the absence of pain, clear signs of infection, or functional impairment of the tooth, such treatment is unjustified and certainly not evidence-based. We extract a physiologic cost every time we “treat” a tooth. We may have improved the radiographic aesthetics of the treatment result; however, the questions that we should be asking are: Has the patient received improvement in his or her quality of life as a result of the treatment rendered? Will the tooth be further weakened with additional treatment? I think we would all agree that such a scenario is not patient-centered.
Q: You have said that in other countries, when discussing dentistry, some call the United States “the Amputation Nation.” Is that fair?
A: Dental care, in many nations, does not have the robust recall tradition that has been promoted in North America. Unless there is a system of socialized health care, patients have little or no insurance and must self-pay, thus decreasing the financial incentive for using indirect restorations. Without a regular recall system, clinicians are less aware of long-term functional or aesthetic failures. In contrast, in North America, insurance reimbursements for indirect restorations are exponentially higher than for direct restorations. We also have a tradition for regular and ongoing care that impacts our patient and professional expectations for long-lasting treatment. As a profession, we have been skeptical that traditional bonding can have similar longevity and aesthetics vs a crown. Thus, our bias is to treat more teeth with crowns, often without solid evidence supporting these treatment choices. We should accept a reasonable, but limited, life expectancy for any treatment and weigh such expectancy relative to the invasiveness of the treatment and remaining options for future revision. Thus, our treatment planning should have context. For instance, how confident are we that an implant restoration can last a lifetime in a 30-year-old vs a 60-year-old? Astute clinicians are becoming increasingly aware of implant longevity and complications. The pendulum is swinging back toward preservation and restoration of the natural tooth. We need a shift in our professional expectations and modus operandi. Our patients’ life expectancies are much longer, and our professional care for them will be a marathon. We believe that this entails a focus on preservation of tooth structure rather than accelerating toward terminal treatment options.
Q: How can clinicians serve their patients better in the long-term without resorting to so many crowns?
A: The first intervention is critical. Pediatric dentists and restorative dentists need to be given the tools to potentially provide 20-year, not 2-year, outcomes when they place the first direct restoration. That is the mission of the Bioclear Learning Centers, now located in 3 countries. We are also working with a dozen dental schools to discuss modernizing the restorative curriculum. We don’t need a better filling material. We need a better procedure!
Q: What if a restoration fails or a tooth is broken?
A: Patients are willing to go to extreme lengths once they realize that crowns require us to remove potentially 74% of the tooth’s coronal volume. When quizzed, many dentists think that number is closer to 30%. Think about it: How many dentists avoid crowns on their own teeth? Recently, I treated the wife of a dentist who had failed bonding, replacing almost half the incisal length of her maxillary central incisors. She was specifically referred to me for injection overmolding with the Bioclear Method. This was not an easy case at all, and, technically, crowns are much easier to do. After seeing the final result, the patient looked me in the eye and said, “Dr. Clark, I’m so glad you didn’t have to do crowns on my 2 front teeth! Thanks!” Wow! Not quite what we would expect to hear. Patients intuitively and understandably fear having their teeth ground down. Injection overmolding of teeth, which avoids sacrificing tooth structure, is a patient-centered procedure that is rapidly growing as a treatment alternative. After placing thousands of these restorations, my partner, Dr. Jihyon Kim, and I have the confidence to provide 10-year warranties on them.
Monolithic injection-overmolded restorations are built upon a foundation of complete biofilm removal; the injection of heated flowable and regular composite; the placement of ultra-thin anatomic tooth forms that allow monolithic composite to shrink-wrap the tooth; and achieving a rock-star polish. This method provides a third option of treatment. Unlike direct bonding, it can be as permanent as crowns when done properly. Unlike crowns, it does not require sacrificing a significant volume of healthy tooth structure to accommodate a path of insertion or other mechanical properties of modern ceramics. With indirect options, the tooth must be shaped to accommodate ceramic needs. With direct injection overmolding, the composite adapts around the existing tooth structure.
Q: Any additional thoughts on the topic?
A: Similar to how we amputate healthy tooth structure for indirect restorations, in endodontics, we remove a hefty volume of peri-cervical and radicular dentin to target the process outcome of the tapering shape of obturation materials and technique. Canals are typically not round in cross-section or tapering from the coronal to apical dimension. Thus far, these traditional shaping protocols have not been linked to any improvement in outcomes and may even have reduced positive long-term outcomes. In fact, crown and root fractures are now epidemic. We need to adapt the obturation material to fit the canal.
Dr. Clark maintains a private practice in Tacoma, Wash. He founded the Academy of Microscope Enhanced Dentistry and is a course director at the Newport Coast Oral Facial Institute in Newport Beach, Calif. Dr. Clark is a co-director, along with Dr. Jihyon Kim, of the Bioclear Learning Center in Tacoma. He can be reached at bioclearmatrix.com.