Tissue healing of immediate implant placement in extraction sockets with titanium versus zirconium oxide implants : an experimental study in the beagle dog

Tese de doutoramento, Medicina Dentária (Periodontologia), Universidade de Lisboa, Faculdade de Medicina Dentária, 2016Objectives: To compare and evaluate the biomechanical, radiographic and histological behavior of zirconia and titanium implants placed into extraction sockets. Materials and methods: Five Beagle dogs received 15 titanium implants (Ti) and 15 zirconia implants (Zr) immediately placed into the distal socket of the second, third and fourth premolars. Implant stability and radiographic evaluation was performed at the time of implant placement and sacrifice. Animals were sacrificed at 1, 2, 4, 8 and 12 weeks. Peri-implant mucosa dimensions, marginal bone loss and bone-to-implant contact were evaluated. Kruskall-Wallis test, Mann-Whitney test and Spearman correlation analysis were used when appropriate. Values of p .05). The buccal peri-implant mucosa ranged between 3.54 ± 0.23 mm (Zr) and 3.93 ± 0.49 mm (Ti) (p > .05). The buccal bone crest was located 1.53 ± 0.15 mm (Ti) and 1.55 ± 0.12 mm (Zr) (p > .05) below the implant shoulder (p = .05). The BIC, NBF and TBA were 59.4 ± 0.75 % (Ti) and 57.8 ± 2.26 % (Zr), 65.37 ± 3.05 % (Ti) and 63.63 ± 3.79 % (Zr), 77.97 ± 2.08 % (Ti) and 75.1 ± 2.31 % (Zr) respectively (p > 0.05). Conclusions: Even though zirconia implants exhibited less primary stability when compared to titanium implants they reach a similar degree of stability over time. Zirconia implants did not prevent the remodeling of the extraction socket. Zirconia implants rendered similar peri-implant soft tissue dimensions, ridge alterations and osseointegration when compared to titanium implants