Assessment of the relation between the existence of mandibular second molar distal cervical caries and presence of a partially erupted mandibular third molar in an Iranian population

Abstract

Partially erupted mandibular third molar is a risk factor in the presence of distal cervical caries on the adjacent second molar. The purpose of this study was to analyze the correlation parameters between the distal cervical caries of the mandibular second molars and the radiographic features of the mandibular third molars. Methods and materials: This study was carried out at the department of oral radiology. 302 periapical and bitewing radiographs showing a partially erupted mandibular third molar were studied. The variables analyzed were: tooth number, gender, age, radiographic presence of distal cervical caries on the second molar, Pell and Gregory classification, Winter classification and the presence of contralateral maxillary third molar. Results: 172 female and 130 male patients were included in the study. Mean age (SD) of male and female patients were 30.2 (6.9) and 29.9 (7.4) respectively. The prevalence of distal cervical caries was 20.9 % and was significantly greater in males and 26-59 years age group. The rate of distal cervical caries was significantly greater when second molar was adjacent to horizontal or mesioangular third molar and when the contact point was on or below the second molar CEJ. Distal cervical caries were significantly associated with presence of contralateral maxillary third molar. Conclusion: Horizontal or mesioangular third molars which are in contact with adjacent second molar on or below its CEJ pose the greatest risk for development of distal cervical caries and their prophylactic extraction are to be suggested.