A pilot study of the effect of three removable partial denture retainers on periodontal health of the abutment teeth

Objective: To compare the effects of three removable partial denture designs (one with RPI retainers, the other two with RPA and RPC retainers) on periodontal health of the abutment teeth. RPC means rest of posterior and circumferential clasp arm. Methods: The periodontal status of the patients wearing removable partial dentures was examined with periodontal indices commonly used in clinics and reproducible X ray examinations, and a group comparison was made using a one way analysis of variance (ANOVA). Results: The effects of the three kinds of retainers on the plaque indices on the buccal surfaces of the abutment teeth were similar, but the effects on those of the lingual surfaces were quite different—individuals with RPA removable partial dentures exhibited lower mean values for the plaque indices than those with RPC partial dentures, which was statistically significant ( P 0.05). Individuals with RPI removable partial dentures exhibited moderate level of plaque indices. The other periodontal indices, such as the gingival index, the probing depth, the alveolar bone loss and the mobility of the abutment teeth, were not significantly different among the three groups. Conclusion: The removable partial denture with RPA retainers is more favorable for patients to maintain the abutment teeth and their periodontal structures in good health. On the other hand, the removable partial denture with RPC retainers should not be used as possibly as one can.