Antimicrobial Effects of Three Different Treatment Modalities on Dental Implant Surfaces
Resolution of peri-implant inflammation and re-osseointegration of peri-implantitis affected dental implants seem to be dependent on bacterial decontamination. The aims of the study were to evaluate the antimicrobial effects of 3 different instrumentations on a micro-textured dental implant surface contaminated with an avirulent or a virulent Porphyromonas gingivalis strain and to determine alterations to the implant surface following instrumentation. Forty-five dental implants (Straumann SLA) were allocated to 3 treatment groups: Er:YAG laser, chitosan brush, and titanium curette (10 implants each) and a positive (10 implants) and a negative (5 implants) control. Each treatment group and the positive control were split into subgroups of 5 implants subsequently contaminated with either the avirulent or virulent P. gingivalis strain. The antimicrobial effect of instrumentation was evaluated using checkerboard DNA–DNA hybridization. Implant surface alterations were determined using a light interferometer. Instrumentation significantly reduced the number of attached P. gingivalis (P < .001) with no significant differences among groups (P = .310). A significant overall higher median score was found for virulent compared with avirulent P. gingivalis strains (P = .007); the Er:YAG laser uniquely effective removing both bacterial strains. The titanium curette significantly altered the implant surface micro-texture. Neither the Er:YAG laser nor the chitosan brush significantly altered the implant surface. The 3 instrumentations appear to have a similar potential to remove P. gingivalis. The titanium curette significantly altered the microstructure of the implant surface.

Flow chart of the study.

SEM images of the SLA implant surface inoculated with Porphyromonas gingivalis: (a) Magnification ×10 000 and (b) magification ×30 000. Asterisks indicate presence of P. gingivalis on the implant surface.

(a) Box plot showing mean roughness area (Sa) for 4 treatment categories of the implants from the tops, the valleys, and the flanks of the threads. (b) Box plot showing density (Sds), number of peaks per unit of area, for 4 treatment categories of the implants from the tops, the valleys, and the flanks of the threads. (c) Box plot showing the hybrid parameter (Sdr), representing the ratio between the developed surface area and a flat reference area, for 4 treatment categories of the implants from the tops, the valleys, and the flanks of the threads.

SEM images of the implant surface at the smooth surface of the neck (a, b) and the rough surface of the body (c, d) following instrumentation with a titanium curette (b, d) and positive control (a, c) (magnification ×3000). Asterisk in b indicates a vertical scratch on the turned neck and in d indicates an area of smoothed out and flattened rough surface of the body following instrumentation.
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