FOCUS ON: Caries Arrest

Rella Christensen, RDH, PhD


Rella Christensen, RDH, PhD, discusses what it takes to stop a developing carious lesion.

Q: Can progression of a carious lesion be stopped clinically without cutting the tooth?
A: Yes, if the following critical factors are in place: (1) patient dedication to sustained maintenance of a low-sugar diet, excellent oral hygiene, and management of saliva flow rate (ie, nondisease-related factors in low saliva flow rate can be medication side effects and/or inadequate fluid intake); and (2) patient access to all developing lesions to allow daily clearance by the patient of biofilm accumulation in these critical areas.

Q: Does placement of dental restorative material arrest caries?
A: Yes and no. Virtually millions of individual teeth have had the caries process arrested by excision of the carious material and placement of a dental restorative material. However, if factors that resulted in the original lesion are allowed to continue, other lesions can subsequently develop in the same oral cavity—and many times, on a tooth just recently treated. Repeated episodes of carious lesions have caused great frustration to patients, dentists, dental educators, and third-party payment organizations. Unfortunately, dental caries is one of the diseases clinically treated vigorously while patients continue known causes.

Dental caries is a microbe driven disease. During the past 11 years, a series of in vivo caries microbiology studies performed by TRAC Research show clearly that the microbes must be controlled before attempting to strengthen and/or repair the tooth, if recurring disease is to be prevented.

Q: Do various commercial products now being dispensed by clinicians to patients help arrest carious lesions already in progress?
A: There is no commercial product that can, by itself, arrest an ongoing carious lesion. In other words, there is no “magic formulation.” In 2016, there is no way around the fact that the patient will need to control dietary choices, oral hygiene, and saliva flow in order to control the microbes driving the caries process. Unfortunately, when clinicians dispense products it can imply to patients that the products can solve their caries problem without their making changes in their habits and choices. The products can raise false expectations and divert attention from the changes necessary. For clinicians, the onrush of typical patient days and the apathy of patients toward changes have bred a reliance on dispensing products they hope will help, perhaps without putting enough emphasis on the critical necessity for changes in diet and oral hygiene. Unfortunately, very few of the currently available products have been subjected to clinical validation using real-world test protocols before market release. By manipulating claims, it is relatively easy to market products with very little evidence of efficacy.

Q: Can a carious lesion arrested by changes in diet, oral hygiene, and saliva flow rate be remineralized?
A: The answer depends on how the patient and dentist define the term “remineralized.” Patients and dental clinicians tend to think when a tooth is “remineralized” it means the defect, such as an opaque white area or a cavitation, will disappear, and the surface will be returned to its previous perfect condition. We have seen this only in cases of very initial white spot demineralization. It does not occur with a visually apparent cavitated lesion or a severe white spot lesion. However, it is possible to cause certain ions to be deposited within a carious defect and technically call this remineralization, without making any visual change to the site. Although some have reported that lesions treated with fluoride ions develop surface layers that are more resistant to re-infection, we have not found this to be the case clinically. Our work shows that when a high-sugar diet and poor oral hygiene return, enamel demineralization returns to the same locations that once may have appeared to remineralize visually.

Q: Does fluoride help prevent caries from occurring in the first place?
A: Yes. Habitual thorough oral hygiene using a fluoride-containing dentifrice along with control of sugar intake and saliva flow, plus use of sealants, can virtually prevent dental caries. Fluoride has a well-established and validated record of aiding in prevention of dental caries. But clinicians and patients need to understand that while fluoride can lower the caries rate, habitual good oral practices also need to be in place. TRAC Research clinical studies have demonstrated the usefulness of PreviDent 5000 plus or booster (Colgate) for prevention of caries and hypersensitivity in particularly susceptible patients. When used as a dentifrice just before bed to brush thoroughly and expectorate, but abstain from water rinsing, it can be very helpful.

Q: Do the new “risk assessment” techniques help?
A: Yes, if the patient is (1) truthful, (2) willing to change patterns that increase risk for dental caries, and (3) willing to undergo regular monitoring. If these 3 points are not present, caries arrest and prevention cannot be accomplished using the risk assessment approach. Unfortunately, often patients find it embarrassing to reveal their actual habits and choices, and are not truthful in providing the essential caries risk information. In addition, clinicians must be alert to the fact that risk factors can change abruptly as significant personal changes occur such as divorce, moving to a new locality, incarceration, deployment, etc. Therefore, risk categorization must be reviewed and revised frequently. It is not prudent to place an individual into a low-risk category and assume that person will maintain that level forever. Furthermore, we must be careful not to let risk categorization deny helpful preventive treatments to patients in the low-risk group. If we categorize patients, we then have the responsibility to review their health status regularly to assure we don’t miss changes. Realistically, getting patients to comply with regular exams can be challenging. Therefore, office recall programs need to be vigorous.

Q: Does the future hold promise for caries arrest and remineralization?
A: Yes. A lot of very intelligent scientists are working in these areas. Dental clinicians, the dental industry, third-party payment organizations, and patients all have high interest in these areas. The problem is patients want to enjoy sugars, poor oral hygiene habits, and multiple medications without worrying about teeth! But definitely the best is yet to come in both caries arrest and tooth remineralization.

Dr. Christensen currently leads TRAC Research Laboratory, which is devoted to clinical research in oral microbiology and dental restorative concepts. TRAC Research is part of the non-profit educational Clinicians Report Foundation (formerly CRA) which she directed for 27 years. Throughout her career she has taught at the under- and post-graduate levels, authored many research abstracts and reports, and received numerous honors. She has performed research within the practices of hundreds of dentists and their teams seeking best patient treatments. She can be reached via email at