Ricerc@Sapienza

Objectives To compare, using an ex vivo model, the biofilm removal of three surface decontamination methods following
surgical exposure of implants failed for severe peri-implantitis.
Materials and methods The study design was a single-blind, randomized, controlled, ex vivo investigation with intra-subject
control. Study participants were 20 consecutive patients with at least 4 hopeless implants, in function for >12 months and with
progressive bone loss exceeding 50%, which had to be explanted. Implants of each patient were randomly assigned to the
untreated control group or one of the three decontamination procedures: mechanical debridement with air-powder abrasion,
chemical decontamination with hydrogen peroxide and chlorhexidine gluconate, or combined mechanical-chemical decontamination. Following surgical exposure, implants selected as control were retrieved, and afterwards, test implants were
decontaminated according to allocation and carefully explanted with a removal kit. Microbiological analysis was expressed in
colony-forming-units (CFU/ml).
Results A statistically significant difference (p < 0.001) in the concentrations of CFU/ml was found between implants treated
with mechanical debridement (531.58 ± 372.07) or combined mechanical-chemical decontamination (954.05 ± 2219.31) and
implants untreated (37,800.00 ± 46,837.05) or treated with chemical decontamination alone (29,650.00 ± 42,596.20). No
statistically significant difference (p = 1.000) was found between mechanical debridement used alone or supplemented with
chemical decontamination. Microbiological analyses identified 21 microbial species, without significant differences between
control and treatment groups.
Conclusions Bacterial biofilm removal from infected implant surfaces was significantly superior for mechanical debridement
than chemical decontamination.
Clinical relevance The present is the only ex vivo study based on decontamination methods for removing actual and mature
biofilm from infected implant surfaces in patients with peri-implantitis.