Long-term inflammatory outcome after placement of a novel two-piece dental implant in a dog model experimental peri-implantitis

Purpose: Evaluate the inflammatory outcome of a two-piece novel titanium dental implant (test article) vs. a one- piece titanium dental implant (control article) inducing experimental peri-implantitis in a dog model. Materials & Methods: A novel, two-piece pre-assembled implant with a 0.2-thickness sleeve in its coronal 4.2 mm part was developed (Test article). Ligature-induced experimental periimplantitis model was applied, followed by decontamination and bone grafting in seven dogs. Four groups were assessed according to decontamination and resurfacing protocol: E1 (Experimental 1): test article- sleeve removed, mechanical and chemical decontamination, new rough surface non-threaded sleeve was inserted; E2 (Experimental 2): test article- sleeve removed, mechanical and chemical decontamination, test article remained denuded presenting a turned non-threaded surface; C1 (Control 1): sleeve remained, mechanical and chemical decontamination in test article, original rough surface, non-threaded sleeve; C2 (Control 2): control article cleaning, mechanical and chemical decontamination of original rough surface, threaded implant. Buccolingual and mesiodistal sections were prepared for each site. Resin qualitative and semi-quantitative histopathologic inflammatory parameters were analyzed. Results: Group C1 showed statistically significant highest signs of residual long-term inflammation, followed by groups E1, and C2. Group E2 displayed the lowest local inflammation. Mesio/Distal aspects displayed increased long-term inflammatory infiltrate albeit not statistically significant. Conclusions: Within the limits of the present study, it may be concluded that – (1) The decontamination procedure is more effective in a commercial one-piece vs. a two-piece dental implant. (2) Mechanical and chemical decontamination outcome is insufficient. Resurfacing improves the decontamination outcome. (3) Decontamination of the turned surface is superior to the rough surface. Clinical relevance: When choosing the most appropriate dental implant for individuals with a high risk for peri-implant disease, a one-piece dental implant with a turned crestal surface is preferable. Once occurring, the control of peri-implant disease inflammation may be more successful. Decontamination is usually not enough. Resurfacing is highly recommended if possible.