2009 Volume 1 Issue 2 Pages 130-138
Purpose: The purpose of this retrospective cohort study was to investigate how removable partial dentures (RPDs) affect the periodontal condition of abutment teeth adjacent to an edentulous area.
Methods: One hundred and sixty-one patients were treated with RPDs, which were delivered by dental students under supervision, at the Tohoku University Hospital between 1996 and 2001. Of the 161 patients, 67 patients who agreed to undergo a follow-up examination were re-examined 5 years after treatment. The study population was categorized into three groups based on the status of the RPDs: successful, replaced and failed. The successful group consisted of 37 patients with 48 RPDs. They had 137 abutment and 219 non-abutment teeth. Of the 81 direct abutment teeth, 41 were adjacent to free-end edentulous areas and 40 adjacent to bounded edentulous areas. The variables analyzed in this study were: 1) O'Leary's Plaque Control Record (PCR), 2) Pocket depth, 3) Miller's tooth mobility, and 4) Bone resorption level. The Wilcoxon signed rank test was used for statistical analysis.
Results: The abutment and non-abutment teeth showed statistically significant deterioration in PCR, pocket depth and bone resorption level between the time of placement and five years later. However, significant differences were not found in tooth mobility of the abutment teeth, whereas significant improvement was found in the non-abutment teeth. The pocket depth and bone resorption of the direct abutment teeth adjacent to a free-end edentulous area deteriorated significantly, while those adjacent to a bounded edentulous area were unchanged.
Conclusion: The periodontal condition of the abutment and non-abutment teeth changed in the five years following RPD placement. The effect of wearing RPDs on direct abutment teeth might differ with the location of the teeth and position of the clasp around the tooth.
