Managing Caries Risk: A Paradigm for the 21st Century?

Dr. Richard Valachovic
In this month’s letter, ADEA President and CEO Dr. Rick Valachovic considers a movement among oral health professionals that favors prevention and the medical management of dental disease.

Last month, two events—the launch of government-run health insurance exchanges and efforts in Congress to delay and defund other aspects of the Affordable Care Act—focused my attention once again on ways that our professions’ roles in the health care system are changing. Not all—or even most—of that change comes in response to the evolution taking place in the U.S. health care system. Nevertheless, recent events reinforce what we have known for some time: that the oral health professions will look markedly different in the 21st century than they did in the 20th.

While some aspects of what lies ahead remain hard to predict, it’s apparent that greater integration of the health professions—of education, research and practice—and of the body, the mind and the oral cavity are well underway. As a result, I’ve decided to focus the next two issues of Charting Progress on practices that are bridging the historic divide between dentistry and other health professions. This month, let’s start by looking at a medical approach to managing oral health using caries risk assessment. By now, this term should be familiar to most in our community. A 2009 survey of dental schools indicated that 90% of responding institutions had a caries risk assessment program in place for their predoctoral students, and 59% listed caries risk assessment as a graduation requirement. Nearly all dental hygiene programs also teach their students to assess caries risk. These numbers are even higher today according to Dr. Margherita Fontana, Associate Professor in the Department of Cariology, Restorative Sciences and Endodontics at the University of Michigan School of Dentistry. Margherita helped conduct a more recent survey of caries risk assessment in the predoctoral dental curriculum. She told me that all schools now say they teach the practice, but there is significant variation in how they do it.

“One of the challenges has been to make sure that caries risk assessment is consistently implemented with every patient who comes to the dental school setting,” said Margherita. “Even in the schools that are most committed to caries risk assessment, there are still a number of patient charts that might not have the required assessment forms completed.”

As you may know, Margherita has been a leader in the ADEA Section on Cariology, and she is a leading proponent of caries risk assessment, although she readily admits there is still some confusion among oral health professionals about caries risk assessment generally and about CAMBRA specifically. The CAMBRA acronym stands for Caries Management by Risk Assessment, which is both a philosophy and a method for managing the disease of dental caries. The term also applies to a survey tool for discovering what puts patients at risk of developing dental caries and to treatment approaches that aim to reduce that risk.

“The strategies we choose and the frequency with which we monitor patients is based on each patient’s risk,” Margherita explained. “And if we have to intervene restoratively, we’re going to try and preserve as much tooth structure as possible.”

This view stands in stark contrast to the concept of “extension for prevention” pioneered by Dr. G.V. Black, the founder of modern operative dentistry. Anyone who has studied restorative dentistry is familiar with Dr. Black’s seven steps for restoring carious lesions. Step seven, “performing the toilet of the cavity,” is especially memorable since his cleaning procedure long outlived the colorful phrase he used to describe it.

Dr. Black’s “extension for prevention” idea, conceived in the late 19th century and promulgated in textbooks throughout the 20th, was that carving away healthy portions of the tooth adjacent to the decay would prevent future carious involvement. This seemed to make sense at a time when acid was deemed to be the primary cause of dental caries, but remarkably, Dr. Black’s approach to restoration continued to persist in the second half of the 20th century despite our growing understanding of the bacterial genesis of caries and the ability of fluoride and other agents to fortify tooth enamel. In other words, our surgical orientation to treating the problem remains firmly entrenched in many, if not most, dental offices.

That said, in the 1990s, things started to change. A group of researchers led by Dr. John Featherstone, Dean of the University of California, San Francisco, School of Dentistry (UCSF SOD), conducted research that put to rest any lingering notion that placing restorations cured the disease of caries. Their multi-year randomized clinical trial of caries management by risk assessment found that the use of a chlorhexidine rinse following the restoration of teeth with carious lesions reduced the bacterial load in the mouths of adults, whereas placing restorations alone did not.

It wasn’t long before these same researchers and other California dental educators came together to act on these findings. With the support of the California Dental Association, they formed a coalition to promote the routine use of the caries risk assessment and treatment protocols they had named “CAMBRA.” Starting from the premise that caries should be managed medically, they focused on controlling the microflora of the mouth and remineralizing those teeth with weakened enamel. To determine the best way to achieve this for each patient, they developed a CAMBRA assessment form that documents the factors contributing to a patient’s risk of developing caries. (You can see the most recent version of the form incorporated in an iPhone app called MyCAMBRA, which UCSF SOD launched earlier this fall.)

Over the years, a number of other caries risk assessment forms have been developed or adapted in North America and Europe, where caries risk assessment is also gaining ground. I asked Margherita what distinguishes them from one another.

“The forms are all basically measuring the same variables,” she told me. “It’s how they word the questions and how they weight the answers that is different. The reason you have those differences is because there’s not a lot of evidence around how to use the majority of existing forms. It’s primarily based on expert opinion and data on the predictive ability of individual risk factors.”

In other words, the jury is still out on which forms and protocols are most effective in assessing risk and guiding effective preventive treatment. Margherita told me that very few questions on the forms have been shown to be predictive, and those that have been confirm what we already know from the literature: that a patient’s past experience of caries is the best predictor of future caries risk. So why not just assess caries risk based on a patient’s caries experience?

According to Margherita—who received a highly prestigious Presidential Early Career Award for Scientists and Engineers last year, which she is using to develop a caries risk assessment form that can be used by patients rather than clinicians—the forms are as much about managing caries risk as they are about predicting it. The information they gather—about dietary habits, knowledge of oral hygiene, access to fluoridated water and the like—sheds light on a range of factors that are germane to a patient’s dental treatment plan. This information allows for the customization of care, which has the potential to more effectively engage the patient in a preventive oral health regimen than the one-size-fits-all advice to brush and floss.

In the United States, the CAMBRA movement has grown beyond its West Coast roots. Eastern and Central U.S. CAMBRA coalitions came into existence a few years ago, and the formation of a nationwide CAMBRA Coalition is underway. In 2010, CAMBRA Coalition members were also among those who formed the ADEA Section on Cariology to discuss and enhance teaching in this area. The section’s former Councilor is Dr. Mark Wolff, Professor and Chair of the Department of Cariology and Comprehensive Care and Associate Dean for Pre-doctoral Clinical Education at New York University College of Dentistry (NYUCD). He has been influential in seeing that caries risk assessment is performed by both dental and dental hygiene students for all patients who pass through the NYUCD clinic. From what I hear, performing caries risk assessment is not yet routine in some dental school clinics, but the bigger challenge, in Mark’s view, is customizing preventive strategies for adults. He notes that prevention efforts have largely been limited to children, and he’s not satisfied with this.

“Every one of my students, 360 of them a year, graduate saying, ‘What do you mean fluoride for adults isn’t the norm?’” Mark told me, adding proudly, “We’re changing it.”

This advance is laudable, but fluoride at all ages is not the same as providing the type of customized treatment that Mark and others advocate. One obstacle to achieving their vision is a lack of strong evidence on adult preventive care, and as Mark points out, such evidence is urgently needed.

“We have yet to see the real high-risk group in dental caries arrive on the scene: elderly people of limited means,” Mark observed. “Their dexterity is decreasing, their prescription drug use (which in many cases causes dry mouth) is increasing and they still have their teeth with lots of repair done on them. That’s a formula for disaster, so managing their caries risk starts to become very important.”

Perhaps, but effectively managing caries risk for the majority of our patients will require a cultural change on our part, and that never comes easily.

“People who have learned an intensive, detailed skill set like dentistry don’t really want to change and do something different,” John Featherstone remarked when we spoke earlier this fall. As a result, he focuses most of his energies on his current students with the hope that the next generation of oral health professionals will view caries risk assessment as the norm. Meanwhile, he hasn’t given up on current practitioners entirely. John offers a lot of continuing education courses on CAMBRA. (You will be able to read about his recent MOOC, or massive open online course, on the topic in a future issue of the ADEA CCI Liaison Ledger.) And he is seeing some positive results.

“I get feedback every time,” he told me, “from someone who says, ‘This has changed the way I do my practice. It’s changed the way that my patients behave, and it’s changed their oral health.’”

If the experience of these practitioners can be widely replicated, we may start to see the power of prevention begin to transform our approach to combating dental disease. Overcoming another obstacle—the lack of reimbursement for most preventive services—is already being explored by several forward-looking insurers. In one pay-for-performance pilot, reimbursement for caries risk assessment drove the use of risk assessment to 98%! The American Dental Association is also paving the way for insurance reimbursement by introducing three new dental procedure codes in 2014: one each for low, moderate and high caries risk.

Should managing caries risk dominate the practice of dentistry and dental hygiene in the century ahead? Regardless of your answer to that question, we must rethink the way we approach patients, both as individuals and from a community perspective. We cannot simply follow the status quo if we want to be effective in promoting oral health. When it comes to patients, we need to look at their diets and oral health beliefs as well as their oral hygiene. As for communities, we must consider demographics, cultural traditions and infrastructure (from water fluoridation to the availability of healthful food) if we want to reduce the future incidents of caries. Gathering this data through caries risk assessment, regardless of the specific protocol, appears to be a promising way of committing ourselves to intervening with individually tailored preventive strategies before caries recur. Such action is all to the good.

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