Question: In cases of notching and attrition/ wear in non-carious teeth, what are some recommendations for deciding when to intervene?
Before addressing the problem we must determine the causative factors. These include bruxism, dietary habits, facial and muscular structures, acid reflux (eg, GERD), parafunctional habits, developmental defects, iatrogenic (or faulty dentistry), and salivary hypofunction. Restoring the destruction caused by these conditions will only address the symptoms and not the cause.
Before restoring, we must consider the use of nightguards to help control bruxism, equilibration, dietary controls (especially of acidic and hard foods), control of both intrinsic and extrinsic acids using products that will help neutralize the oral cavity pH, etc. We must evaluate the patient's brushing habits and educate the patient not to be too aggressive and to use a soft brush. We may need to replace or polish worn crowns to make them less abrasive, especially if opposing natural dentition. If the patient is missing teeth, we should consider replacement to stabilize their bite. If we have a patient suffering from dry mouth they will need to be placed on a fluoride rinse or gel as well as an artificial saliva. We may also choose to use cavity varnish and xylitol gum.
Once the causative issue is identified and addressed as best it can, we may need to treat the damaged teeth. Treatment decisions should be based on the amount of destruction, if the dental or pulpal integrity is threatened, if there is compromised function, esthetics, or sensitivity. We may decide that no treatment is needed, especially if there is no progression, no threat to dental or pulpal integrity, or no alteration in function and esthetics. If we do treat the destruction, we have many options ranging from direct composites, individual crowns and implants, to full-mouth rehabilitations.
As the population ages and retains their teeth we will see a significant increase in non-carious tooth destruction. As healthcare providers, we must be able to treat both the symptoms as well as the cause of this disease state.
The issue of when to intervene in cases of non-carious tooth destruction will no doubt vary from clinician to clinician depending on individual treatment philosophy (conservative or more aggressive), as well as esthetic considerations as expressed by the patient.
In general, I believe it is most prudent to consider first and foremost the likely sequelae of doing nothing. If the esthetic situation is not of concern, and if the judgment of the clinician is that the situation will not appreciably worsen, or only very slowly deteriorate in terms of weakening the tooth or affecting the rest of the dentition, then the most rational treatment to consider is no treatment at all to the specific area of tooth loss. However, if the ongoing wear or attrition is judged to be getting progressively worse, or if esthetics demands it, then consideration has to be made for preventing further destruction and weakening of the tooth by restoration of the area in a manner that will strengthen the tooth and improve the esthetics.
In addition to intervening or not, the clinician also needs to try to diagnose the cause of the non-carious loss of tooth structure. Eliminating the cause of the non-carious tooth destruction would enhance the probability that the treatment rendered will be successful by removing the potential for breakdown of the restoration from additional adjacent tooth loss. If "no treatment" is the treatment of choice, then elimination of the cause is, of course, also desirable. However, even if the cause cannot be eliminated, treatment for the area of tooth loss could still be beneficial because it should slow down further loss of tooth structure and improve the esthetic appearance of the area.
There are no clear intervention guidelines for non-carious cervical lesions (NCCL) and occlusal and incisal-edge attrition. There are articles describing etiology and restoration of these non-carious destructive processes, but little has been written concerning when to intervene. Is it acceptable to restore NCCLs caused by abrasion, dietary erosion, or abfraction to control a patient's chief complaint of cervical hypersensitivity when less invasive treatment recommendations using sensitivity toothpastes or in-office desensitizing agents are well accepted? When the cervical notching is asymptomatic, when do you restore and what materials should you use?
Normal physiologic wear due to occlusal function has been reported to be as much as 29 µm a year; when parafunction and other conditions exist, the wear is more pronounced. For teeth with incisal-edge or occlusal-surface attrition due to bruxism and clenching, or when the enamel has been weakened from acid attack from GERD, the same questions arise. When and how and to what extent do you intervene?
Understanding why wear is occurring does not help to determine when to intervene restoratively during the early stages of the destruction. Hypersensitivity is one reason to restore; size and depth of the notching is another. I use the guideline of more than 2 mm incisal (occlusal)-gingival height and 1 mm in depth. Usually I make this decision based on the acute changes occurring. I will make an impression of the teeth with NCCLs, and at the 1-year recall I compare the study cast to the clinical lesion for any changes. If changes are occurring, I restore. Attrition is going to continue. The decision to restore wear should be made when the dentin is exposed and demonstrates the "cupping out" phenomenon. Even though these are general guidelines, each patient and each circumstance needs to be evaluated individually to determine clinical recommendations for treatment.
About the Authors
Gerard Kugel, DMD, MS, PhD
Dr. Kugel is the associate dean for research and professor of Prosthodontics and Operative Dentistry at Tufts University School of Dental Medicine in Boston, Massachusetts.
Richard Simonsen, DDS, MS
Dr. Simonsen is the dean and a professor at the Midwestern University College of Dental Medicine in Glendale, Arizona.
Howard E. Strassler, DMD
Dr. Strassler is a professor and the director of Operative Dentistry in the Department of Endodontics, Prosthodontics, and Operative Dentistry at the University of Maryland Dental School in Baltimore, Maryland.