Necessity of removing implant-supported prostheses when conducting supportive peri-implant therapy: A clinical study

Poor or lack of adherence to supportive peri-implant therapy (SPIT) or supportive care has been associated with a significantly higher rate of peri-implantitis or peri-implant mucositis. However, whether therapy with or without the removal of an implant-supported prosthesis yields different outcomes remains unclear.

The purpose of this clinical study was to evaluate the efficacy of ultrasonic devices in treating participants with or without the removal of implant-supported prostheses after more than 12 months of loading.

Twenty participants with 23 implant-supported fixed prostheses (39 implants) with indications for removal were included in this study. The following clinical parameters were recorded before the prostheses were removed: the maximum probing depth (PDmax), bleeding on probing (BOP), months of loading, and complications. Each prosthesis was removed and treated with a regular plaque indicator test and then reinserted. This was followed by the intraoral administration of regular supportive therapy via ultrasonically driven polyetheretherketone instrument tips. After instrumentation, the prostheses were removed to access the area positively stained for calculus or biofilm. PT0 and PT1 show the plaque coverage before and after intraoral ultrasonic cleaning, respectively. The reduction in the positive staining area and the efficacy of ultrasonic cleaning with or without prosthesis removal were measured. The Kolmogorov-Smirnov test was performed to verify that the sample data were normally distributed. Comparisons between PT0 and PT1 were conducted via paired t tests, followed by the Student t test for comparisons between groups (α=.05).

A 27.3 ±15.0% reduction in plaque coverage was observed after the implant restorations had been cleaned intraorally. The efficacy of intraoral ultrasonic cleaning was only 45.4 ±20.6%, with a residual plaque rate of 54.6%. Cleaning without the removal of implant-supported restorations was less effective in participants with a PD >5 mm than in the other participants (P=.001). Neither the emergence angle nor the emergence profile had a significant influence on the cleaning effectiveness (P>.05).

Biofilms at the abutment-prosthesis connection and mucosal and proximal surfaces of the prosthesis may not be effectively cleaned by conventional SPIT. Biofilm reduction is improved by prosthesis removal when the PD is >5 mm.