Fractures of posterior teeth: a review and analysis of associated factors

Abstract

Purpose of study: To examine factors which may predispose to tooth fracture, and to assess the compressive strengths of foods and sweets which are associated with tooth fracture in vivo.

Population studied: Consecutive dental patients presenting with one or more fractured posterior teeth at the surgeries of three general dental practitioners, over a four-month period.

Method: A pro forma was designed to elicit information on the factors associated with tooth fracture and the nature and extent of such fractures. Three general dental practitioners were requested to complete a pro forma for each patient presenting with a fractured posterior tooth over a four-month period. Foods and sweets considered to be associated with tooth fracture were identified and their compressive strengths tested.

Findings: A total of 129 cases of fractured posterior teeth were recorded, of which 48% occurred in the mandibular arch and 52% in the maxillary arch. In the mandible, 75% of tooth fractures occurred in molars while in the maxillary arch 50% occurred in molars. In 57% of cases assessed, no identifiable causative item was noted. Forty-five per cent of fractures were in teeth which had been restored on three or more surfaces. Compressive forces of 0.16KN to 2.2KN were obtained for food items implicated in tooth fractures.

Conclusion: As mesio-occlusodistal restorations were identified as a major predisposing factor to tooth fracture in this study, with mandibular first molar teeth particularly affected, placement of cuspal coverage restorations may be considered to be a justifiable preventative measure in teeth identified as being at risk.