IADR Abstract Archives
Mechanical Evaluation of Two Titanium Alloy Grades Used in Implant Dentistry
Objectives: To investigate the effect of two grades of titanium used in implant-abutment connections on the reliability and failure mode of implants.
Methods: Thirty six titanium implants were divided in two groups (n=18 each): two different grades of titanium were used in the implant-abutment connection to restore single-unit crowns. They were Emfils standard implant (3.5 mm diameter) with a titanium grade II (G.2); Emfils standard implant (3.4mm diameter) with a titanium grade V (G.5). The corresponding abutments were screwed to the implants and standardized maxillary central incisor metal crowns were cemented and subjected to step-stress accelerated life testing in water. Use-level probability Weibull curves and reliablity for a mission of 100,000 cycles at 150N and 200N (90% 2-sided confidence intervals) were calculated. Polarized-light and scanning electron microscopes were used to access the failure modes.
Results: The calculated reliability with 90% confidence intervals for a mission intervals for a mission of 100,000 cycles at 150N showed that cumulative damage from loads reaching 150N would lead to implant-supported restoration survival of ~45% for group G.2, and ~21% for the group G.5.At 200 N and same cycle mission, a survival rate ~0.03% was estimated for the group G.2 and ~21% for the group G.5. Screw fracture was the failure mode for all groups.
Conclusions: The reliability was significantly different between systems at a 150N load. An increase to 200N decreased all of them significantly.
Methods: Thirty six titanium implants were divided in two groups (n=18 each): two different grades of titanium were used in the implant-abutment connection to restore single-unit crowns. They were Emfils standard implant (3.5 mm diameter) with a titanium grade II (G.2); Emfils standard implant (3.4mm diameter) with a titanium grade V (G.5). The corresponding abutments were screwed to the implants and standardized maxillary central incisor metal crowns were cemented and subjected to step-stress accelerated life testing in water. Use-level probability Weibull curves and reliablity for a mission of 100,000 cycles at 150N and 200N (90% 2-sided confidence intervals) were calculated. Polarized-light and scanning electron microscopes were used to access the failure modes.
Results: The calculated reliability with 90% confidence intervals for a mission intervals for a mission of 100,000 cycles at 150N showed that cumulative damage from loads reaching 150N would lead to implant-supported restoration survival of ~45% for group G.2, and ~21% for the group G.5.At 200 N and same cycle mission, a survival rate ~0.03% was estimated for the group G.2 and ~21% for the group G.5. Screw fracture was the failure mode for all groups.
Conclusions: The reliability was significantly different between systems at a 150N load. An increase to 200N decreased all of them significantly.