Aaron Yu-Jen Wu1, Jui-Ting Hsu2, Winston Chee3, Yun-Te Lin4, Lih-Jyh Fuh4, Heng-Li Huang5. 1. Department of Dentistry, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Niao-Sung, Kaohsiung, Taiwan. 2. School of Dentistry, China Medical University, Taichung, Taiwan; Department of Bioinformatics and Medical Engineering, Asia University, Wufeng, Taichung, Taiwan. 3. Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA. 4. School of Dentistry, China Medical University, Taichung, Taiwan. 5. School of Dentistry, China Medical University, Taichung, Taiwan; Department of Bioinformatics and Medical Engineering, Asia University, Wufeng, Taichung, Taiwan. Electronic address: henleyh@gmail.com.
Abstract
BACKGROUND/ PURPOSE: Small-diameter dental implants are associated with a higher risk of implant failure. This study used both three-dimensional finite-element (FE) simulations and in-vitro experimental tests to analyze the stresses and strains in both the implant and the surrounding bone when using one-piece (NobelDirect) and two-piece (NobelReplace) small-diameter implants, with the aim of understanding the underlying biomechanical mechanisms. METHODS: Six experimental artificial jawbone models and two FE models were prepared for one-piece and two-piece 3.5-mm diameter implants. Rosette strain gauges were used for in-vitro tests, with peak values of the principal bone strain recorded with a data acquisition system. Implant stability as quantified by Periotest values (PTV) were also recorded for both types of implants. Experimental data were analyzed statistically using Wilcoxon's rank-sum test. In FE simulations, the peak value and distribution of von-Mises stresses in the implant and bone were selected for evaluation. RESULTS: In in-vitro tests, the peak bone strain was 42% lower for two-piece implants than for one-piece implants. The PTV was slightly lower for one-piece implants (PTV = -6) than for two-piece implants (PTV = -5). In FE simulations, the stresses in the bone and implant were about 23% higher and 12% lower, respectively, for one-piece implants than those for two-piece implants. CONCLUSION: Due to the higher peri-implant bone stresses and strains, one-piece implants (NobelDirect) might be not suitable for use as small-diameter implants.
BACKGROUND/ PURPOSE: Small-diameter dental implants are associated with a higher risk of implant failure. This study used both three-dimensional finite-element (FE) simulations and in-vitro experimental tests to analyze the stresses and strains in both the implant and the surrounding bone when using one-piece (NobelDirect) and two-piece (NobelReplace) small-diameter implants, with the aim of understanding the underlying biomechanical mechanisms. METHODS: Six experimental artificial jawbone models and two FE models were prepared for one-piece and two-piece 3.5-mm diameter implants. Rosette strain gauges were used for in-vitro tests, with peak values of the principal bone strain recorded with a data acquisition system. Implant stability as quantified by Periotest values (PTV) were also recorded for both types of implants. Experimental data were analyzed statistically using Wilcoxon's rank-sum test. In FE simulations, the peak value and distribution of von-Mises stresses in the implant and bone were selected for evaluation. RESULTS: In in-vitro tests, the peak bone strain was 42% lower for two-piece implants than for one-piece implants. The PTV was slightly lower for one-piece implants (PTV = -6) than for two-piece implants (PTV = -5). In FE simulations, the stresses in the bone and implant were about 23% higher and 12% lower, respectively, for one-piece implants than those for two-piece implants. CONCLUSION: Due to the higher peri-implant bone stresses and strains, one-piece implants (NobelDirect) might be not suitable for use as small-diameter implants.
Authors: María Prados-Privado; Juan Carlos Prados-Frutos; Sérgio Alexandre Gehrke; Mariano Sánchez Siles; José Luis Calvo Guirado; José Antonio Bea Journal: Biomed Res Int Date: 2016-07-19 Impact factor: 3.411