Biomechanical evaluation of a microstructured zirconia implant by a removal torque comparison with a standard Ti-SLA implant

• Published in: Clinical oral implants research Vol. 23; no. 10; pp. 1210 - 1216
• Main Authors: Bormann, Kai-Hendrik, Gellrich, Nils-Claudius, Kniha, Heinz, Dard, Michel, Wieland, Marco, Gahlert, Michael
• Format: Journal Article
• Language: English
• Published: Denmark Blackwell Publishing Ltd 01.10.2012
• Subjects: Acid Etching, Dental; Animals; Biomechanical Phenomena; biomechanical testing; Bone implants; Dental Implants; Dental Materials; Dental Prosthesis Design; Dental Stress Analysis; Dentistry; Female; Microscopy, Electron, Scanning; microstructured surfaces; minipigs; Regression Analysis; Surface Properties; Swine; Swine, Miniature; Titanium; Torque; zirconia; Zirconium
• ISSN: 0905-7161; 1600-0501
• DOI: 10.1111/j.1600-0501.2011.02291.x

Objectives The purpose of this study was to evaluate the biomechanical bone tissue response to novel microstructured zirconia implants in comparison to sandblasted and acid‐etched (SLA) titanium implants through the analysis of removal torque (RTQ) measurements. Materials and methods Ti‐SLA implants with a sandblasted, large‐grit and acid‐etched surface were compared with zirconia implants with an acid‐etched surface. All implants had the same shape, a diameter of 4.1 mm and a length of 10 mm. A total of 136 implants were placed in the maxillae of 17 miniature pigs. Six animals were sacrificed after both 4 and 8 weeks and five animals were sacrificed after 12 weeks, thus providing a total of 102 implants for RTQ testing (34 implants were reserved for future histological analysis). The RTQ analysis was successfully performed, using a mixed model regression with P‐values calculated using the nonparametric Brunner‐Langer method, on 100 of the 102 implants, two were excluded from the analysis. Results The adjusted mean RTQ values for Ti‐SLA implants were 131 Ncm (95%CI: 107–155) at 4 weeks, 128 Ncm (108–148) Ncm at 8 weeks, and 180 Ncm (153–207 Ncm) at 12 weeks of healing, whereas RTQ values for the zirconia implants were 110 Ncm (86–134), 97 Ncm (76–118) and 147 Ncm (121–174) at the corresponding time intervals. A comparison of the implant materials resulted in P‐values of P = 0.114 at 4 weeks, P = 0.034 at 8 weeks and P = 0.105 at 12 weeks (significance set at P < 0.05). Conclusions Within the limits of the present study, it could be confirmed that the biomechanical bone‐tissue response of the investigated zirconia implants is non‐inferior to that of the well‐documented, roughened titanium surface, at each time point, within the set tolerance. There were no statistically significant differences between the two materials after a healing period of 4 and 12 weeks. The RTQ values of both implant types increased significantly from the 8‐week to the 12‐week time point.