A reliability study of clinical occlusal tooth wear measurements

Abstract

Tooth wear represents a clinical problem that is becoming increasingly important in ageing populations. Attrition caused by bruxism is its most visible sign. To determine the optimal moment to start the restoration of the worn dentition, one should first be able to measure the amount of tooth wear reliably in the clinical setting. So far, most studies of tooth wear severity have been performed on dental study casts. However, such an indirect approach is less applicable to the everyday dental practice, the more so because by grading of casts, the identification of dentine exposure is hard or even impossible to achieve. In this study, occlusal tooth wear was assessed clinically in 45 volunteers (17 men; 28 women; mean age 33·7 ± 10·7 years), TMD patients and symptom-free persons alike, on four occasions: two calibrated examiners graded the occlusal wear at two different points in time, using a 5-point scale (0=no wear; 1=visible wear within the enamel; 2=visible wear with dentine exposure and loss of clinical crown height <1/3; 3=loss of crown height between 1/3 and 2/3; 4=loss of crown height >2/3). The overall values of the intra-rater and interrater reliability, expressed as Cohen's κ, were substantial (κ=0·632–0·678) and did not differ significantly from one another (repeated measures anova: F3,19=1·428, P=0·266). The clinical variable ‘quadrant’ (e.g. right maxillary dental arch) did not influence the values of κ whereas the interrater reliability during the first session was better for the element types ‘incisors’ and ‘cuspids’ than for the element type ‘premolars’ (one-way anova: F3,23=4·577, P=0·012; post hoc Bonferroni tests: P=0·030 and 0·036). Qualitative assessment of the clinical variable ‘severity of wear’ indicated that the more advanced the tooth wear is, the more reliably it can be graded. The presence of restorations did not influence the reliability. It was concluded that occlusal tooth wear can be assessed reliably in the clinical setting, especially in the anterior parts of a dentition that demonstrates considerable wear. (Supported by the lOT)