The dynamic and static load performance of implant systems with conical implant-abutment connections

In recent years, dental implants have been used extensively in treating tooth losts. The stability of the implant-abutment interface is an important factor that influences load distribution to the marginal bone and internal conical connections have been introduced to provide the stability between implant and abutment. The aim of this study is to compare the fracture strengths of implants with internal conical connection after different dynamic loading cycles. Implants (n:27) were centrally embedded in a polyacetal cylinder with an inner diameter of 20 mm and a height of 30 mm. The implants were centered in the cylinder according to ISO 14801 as simulated bone loss of 3mm from the implant platform. All abutments were placed on the corresponding embedded implants, and the screws were tightened according to the manufacturers recommendations. One implant for each brand were separated for SEM analysis. A hemispherical loading device made of cobalt-chromium alloy was manufactured and seated onto the unmodified abutments. The distance from the center of the hemisphere to the top face of polyacetal cylinder was standardized at 11 mm. Three implants were used to determine the endurance limit. Then all brands were subdivided into four subgroups (n=6), 3 subgroups for dynamic + static loading (test groups; DTI-250, MODE-250, Imp-250, DTI-1000, MODE-1000, Imp-1000, DTI-2500, MODE-2500, Imp-2500), and 1 subgroup for static loading (control group; DTI-0, MODE-0, Imp-0,). The tests were performed by applying a compression load. Dynamic loadings were performed at 3 different cycles; 250.000, 1.000.000, 2.500.00 with 2N preload, with the endurance limit result loads as the upper load limit at frequency of 10 Hz for test groups (n=6). After dynamic loading, static loading was performed with a 5mm/min crosshead speed. Specimens were loaded until failure and all data's were recorded. Results were analyzed statisticaly. As a result, statistical differences were found between the implant brands fracture strenght results after dynamic loading. There is no statistical differences between the fracture strenght values of implants in the same brand after different dynamic loading cycles.