Occlusal Trauma and Non-Carious lesions: The role of Eccentric Movements and Guidance

Background: It has been suggested that occlusal trauma during eccentric movements may be an etiological factor in developing non carious lesions(abfractions). Objective: The objective of the study was to investigate the association between premature contacts during eccentric movements, guidance type, and development of non-carious lesions (NCCLs), while also assessing the impact of demographic factors (age and gender) on lesion formation. Methodology: A total of 100 patients of both gender attending to the clinic for prosthetic treatment were included. Minimum 2 lesions per dentition were selected so 100 participants providing a total sample of 200 teeth. Abfractions per dentition with the depth of at least 1 mm were selected and their and sizes were noted. Size of abfraction was noted using Smith &Knight Tooth Wear Index. 0=tooth contour unchanged, 1=minimum loss of enamel contour, 2= defect less than 2mm in depth, 3= defect between 1-2mm deep, 4=>2mm deep or pulp exposure/secondary dentine. Premature contacts in eccentric guidance were recorded. Number of premature contacts from 0; no contact to 3 i.e., maximum contacts were checked. Number of abfractions from 1 to 6 per dentition were checked. Results: Out of 200 abfraction lesions maximum teeth were having no premature contacts 61.5% followed by 19.5% with 1 premature contact. Maximum number of 4 abfractions per dentition was frequently found 50.0% followed by 3 abfractions 19.0%, only 3.0% teeth had 6 abfraction lesions. The association of development of number of abfraction lesions with premature contacts and age was significant; P <0.05. The type of occlusal scheme (the canine guidance and group function) and gender had insignificant association with the number of developed abfraction lesions; p<0.05. Conclusion: Premature occlusal contacts and increase of age plays a significant role in the development of abfraction lesions, whereas the type of occlusal scheme and gender, do not appear to have substantial affect.