Using Morphological Criteria in Diagnosing Extensive Chemical and Mechanical Tooth-wear

Objectives: The aim was to determine the possibility of allocating patients with extensive tooth wear into three groups; chemical, mechanical and combined based on specific morphological criteria for worn dentition.
Methods: A total of 120 healthy individuals were selected within the range of 17–65 years. The criteria for selection were at least 10 teeth in the upper and lower arches, good periodontal status and at least grade 3 tooth wear according to tooth wear index (Smith & Knight 1984). Photographs and study models were used by two examiners to determine specific morphological criteria for the worn dentition. These morphological criteria were used to allocate the patients into 3 groups: chemical, mechanical and combination. We examined the reproducibility by calibrating 3 general dentists who used the same method to allocate 36 randomly selected patients. We also studied the correlation between the 3 morphological groups and the respective background factors for chemical and mechanical tooth wear.
Results: The final study population comprised of 120 patients (28 females and 92 males), with a mean age of 43.0 years. A total of 42 patients with a mean age of 39.6 were allocated in the chemical group, 27 patients with a mean age of 46.6 were allocated in the mechanical group and 51 patients with a mean age of 44.0 were allocated in the combined group. The absolute agreement between all observers who used the specific morphological criteria was 56% (Fleiss` kappa= 0.65), which indicates good agreement. While the chemical and mechanical groups showed a strong correlation with the background factors for chemical and mechanical tooth wear respectively, the combined group had a significant correlation to both chemical and mechanical background factors.
Conclusions: The morphological criteria for worn dentition are useful for diagnosing the different chemical and mechanical impacts that act on tooth surfaces.