Survival of root filled teeth in general dentistry in a Swedish county: a 6-year follow-up study.

OBJECTIVE: The purpose of the present study was to investigate the survival rate of root filled teeth in general dentistry in a Swedish county and to identify risk predictors with a significant influence on the survival rate. MATERIALS AND METHODS: This is a retrospective 6-year follow-up study on 1642 recall patients with 1720 teeth root filled in general dentistry in the Public Dental Service in the county of Stockholm, Sweden. Background variables were collected from the database at baseline as potential predictors of tooth loss. The outcome variables were extraction during the 6-year follow-up period and the reason for the extraction. Stepwise Cox regression analysis was adopted in order to investigate the influence of the potential risk predictors on the risk for tooth extraction. RESULTS: Nine percent of the root filled teeth were lost after 6 years. The most frequent reason for tooth loss was fracture and/or cracks (58%). The survival rate of the root filled teeth increased significantly for younger patients, root filled teeth with metal crowns (96%) and high quality of the root filling (93%). The survival rate differed significantly between tooth groups with the lowest survival for molars (83%). Composite fillings were significantly associated with lower quality of the root fillings. CONCLUSIONS: Ninety-one percent of the root filled teeth survived after 6 years. The survival rate was significantly higher for teeth with root-fillings of high quality and metal crowns as well as for root filled teeth in younger patients. The lowest survival rate was found for molars.

The adoption of nickel-titanium rotary instrumentation increases root-filling quality amongst a group of Swedish general dental practitioners.

The aim of the present study was testing the hypothesis that the adoption of nickel-titanium rotary instrumentation (NTRI) will improve the technical quality of root-fillings. The investigation was carried out within a mandatory continuing education program (CEP) for general dental practitioners (GDPs). The study was conducted amongst GDPs employed by the Public Dental Health Service in the County of Stockholm. Identical questionnaires were distributed before the CEP (Pre-Q) and 9 to 12 months after the course (Post-Q). The CEP consisted of two parts: lectures and hands-on training. From each GDP, radiographs of two cases completed before the course and two cases treated 9-12 months after the course were randomly selected. Primarily molars were selected for evaluation. The radiographs were individually evaluated by two endodontists. Teeth treated before and after training were presented in random order. Adoption rate of NTRI increased from 35% to 75%. Cases from 124 GDPs were included in the final analysis. The rate of good quality root-fillings increased from 27% to 49% (p<.001). A significantly increased radiographic quality was found between GDPs adopting NTRI and those who did not. The GDPs produced root-fillings of very poor quality before as well as after the training period. However, the rate decreased from 29% to 12% amongst adopters and from 46% to 28% amongst non-adopters. Dentists considering canal preparation and root-filling as "easy" produced more frequently good quality root-fillings than the others (p<0.05). In conclusion, the results of the present study were in favour of the idea that a shift to NTRI increases the technical quality of root-fillings produced by GDPs. However, adopters still produce root-fillings of very poor quality. This important issue needs to be addressed in future studies.