Relative contribution of restorative treatment to tooth extraction in a teaching institution.

Teeth can be extracted due to multiple factors. The aim of this retrospective cross-sectional study was to identify the relative contribution of restorative treatments to tooth loss. The study reviewed records of 826 patients (1102 teeth). Patient's gender, age and education were obtained. In addition to the main reason for extraction (caries, periodontal disease, pre-prosthetic extraction, restorative failure and remaining root), the following information was collected about each extracted tooth: type, the status of caries if any (primary or secondary) and pulpal status (normal or reversible pulpitis, irreversible pulpitis, necrotic or root canal treated) and type and size of restoration, if present. Following data collection, descriptive analysis was performed. A log-linear model was used to examine the association between restorative treatment and tooth loss and between reasons for tooth loss and type of tooth. Lower molars followed by upper molars were the most commonly extracted teeth. Teeth with no restorations or with crowns were less likely to be extracted (P < 0·001). Lower and upper molars and lower premolars were more likely to be extracted due to restorative failure, while lower anterior teeth were more likely to be extracted due to periodontal disease (P < 0·05). Twenty two per cent of the extractions was due to restorative failure, and at least 65·9% of these teeth had secondary caries. Gender, age and educational level were factors that affect tooth loss. In conclusion, teeth receiving multiple restorative therapies were more likely to be extracted.