An evaluation of the long-term wear of a distal extension-removable partial denture on abutment teeth that have undergone periodontal therapy

Although the evidence is clear on the long-term effects of removable partial dentures (RPDs) on the periodontal health of abutment and non-abutment teeth, little work has been done on the periodontal outcomes of the remaining teeth previously treated with periodontal therapy. The aim of this study was to evaluate the effect of denture loading on teeth previously exposed to periodontal treatment with additional photo-disinfection. Twelve partially edentulous patients classified as having mandibular Kennedy Class I arches were included. In each quadrant of the mandibular arch, the terminal abutment was diagnosed to have untreated chronic periodontitis. Initially, all the affected abutments received a conservative periodontal treatment in form of scaling and conventional root debridement. Patients were randomly received additional treatment with photodynamic therapy in one of the mandibular quadrants (test group). After the periodontal treatment, a 4-week load-free period was planned. Mandibular distal extension RPDs was fabricated to restore the missing teeth. The clinical periodontal parameters including plaque index (PI), gingival index (GI), gingival recession (GR), probing pocket depth (PD), clinical attachment level (CAL) and tooth mobility (TM) were assessed at baseline, and then for two additional 6-month recall appointments over a period of twelve months after prosthetic treatment. In addition, the mean annual vertical bone loss was also assessed. Except for the PI, GR, and PD, values for the mean GI, CAL, and TM scores at the test group were significantly lower than those in the control group. Better annual vertical bone loss results were observed on the proximal sides of abutments treated with additional photodynamic therapy. The results of this study suggest that RPD abutments affected by chronic periodontitis may perform better as abutments for distal extension RPDs when treated with both conventional root debridement and additional antimicrobial photodynamic therapy.