Prevalence of periapical lesions, root canal treatments and restorations in teeth adjacent to implant- or tooth-supported crowns: A multi-centre cross-sectional study

Aim: To describe the prevalence of periapical lesions, root canal treatments and coronal restorations on teeth adjacent to either implant- or natural tooth-supported crowns using cone-beam computed tomography (CBCT) assessment compared to nonadjacent teeth. Methodology: A total of 1249 CBCT volumes were screened by five pre-calibrated observers in 11 health centres. A step-by-step screening protocol was implemented and reviewed every 3 months, and mandatory setting characteristics were established for all CBCT scans using dedicated visualization software. Intra- and inter-rater reliability tests were conducted. The prevalence of periapical lesions, root canal treatments and coronal restorations was recorded on both teeth adjacent and nonadjacent to implant- (predictor 1) or natural tooth-supported crowns (predictor 2). A binary logistic model (Generalizing Estimating Equations test) was used to verify whether the prevalence of periapical lesion, root canal filling and the tooth restorative status are altered when the assessed tooth is adjacent or not to an implant-supported crown (predictor 1); or to a natural tooth-supported crown (predictor 2). Odds ratio and confidence intervals for the dependent variables at both predictors were obtained. The significance level was set at.05. Results: A global sample of 22 899 teeth was included. Compared to nonadjacent teeth, the prevalence of periapical lesion, root canals treatments and restorative procedures when adjacent to implant-supported crowns was 10.7%, 19.6% and 22.9% higher, respectively, and when adjacent to tooth-supported crowns was 19.3%, 35.6% and 37.4% higher respectively. These results were significant only for variables root canal filling and coronal restoration (p <.0001). Odds ratio to present root canal treatment is 2.57 times higher (CI 1.95–3.39, p =.0001) when the tooth is adjacent to implant-supported crown and 4.39 times (CI 3.49–5.53, p =.0001) when adjacent to tooth-supported crown, whilst for restorative procedure, the odds are, respectively, 1.63 (CI 1.29–2.06, p =.0001) and 2.30 (CI 1.92–2.76, p =.0001). Conclusions: Teeth adjacent to both implant- and natural tooth-supported crowns were associated with a higher frequency of root canal filling and coronal restorations.