Zirconia and Titanium Implants Placed at Two Supracrestal Levels in Fresh Extraction Socket: Canine Periodontitis Model

AIM: To compare clinical and radiographic outcomes of titanium and zirconia implants placed supracrestally into fresh extraction sockets in a canine model with naturally occurring periodontitis. MATERIALS AND METHODS: A total of 32 implants were placed in eight dogs. The titanium (Control, Group 1) and zirconia (Test, Group 2) implants with a 0.4 mm machined collar were placed into fresh extraction sockets at two vertical positions: 0 mm (subgroup a) and 1 mm (subgroup b) exposure of rough surface to make the artificial condition of alveolar bone loss around the implant. Peri-implant mucosal tissue inflammation (MTI), implant stability quotient (ISQ), and marginal bone loss (MBL) were evaluated at 6, 12, and 18 weeks postoperatively. RESULTS: Zirconia implants demonstrated comparable results to titanium in implant stability and peri-implant soft tissue response. Although MTI scores were slightly higher in zirconia implants than titanium for the entire period, there was no significant issue during osseointegration. The ISQ values increased significantly at 6 weeks in all groups. Mean MBL gradually increased over time; among implants with exposed rough surfaces, Group 1b exhibited the highest MBL (0.71 ± 0.38 mm), whereas Group 2b showed significantly less bone loss (0.32 ± 0.30 mm) (p = 0.05). CONCLUSIONS: In natural periodontitis canine model, titanium and zirconia implants placed into fresh extraction sockets demonstrated similar stability during healing period. Zirconia implants exhibited significantly less MBL than titanium under the condition of rough surface exposure, indicating a more favorable peri-implant bone response with zirconia.