A technique for the removal of a wedged implant abutment fragment or debonded titanium base

A retrospective study of 12,538 internal conical connection implants: focused on the long-term integrity of implant-abutment complexes

OBJECTIVES

To evaluate the long-term integrity of implant-abutment complexes in implant systems with two internal conical angles.

MATERIAL AND METHODS

12,538 bone-level implants of two systems placed between January 2012 and December 2018 were retrospectively analyzed. Cumulative abutment/implant fracture rates in systems with larger (LA, 7.5°) and smaller (SA, 5.7°) internal conical angles were estimated using Kaplan-Meier analysis and compared between groups. The association between implant systems and jammed abutment retrievability was evaluated by multivariable generalized estimating equation logistic regression modelling.

RESULTS

For LA, the 8-year cumulative incident rate was 0.10% (95% confidence interval (CI): 0-0.24%) for implant fracture and 0.26% (95% CI: 0.11%-0.41%) for abutment fracture, demonstrating a significant difference in gender (p = 0.03), implant diameter (p = 0.01), jaw (p = 0.006) and antagonist tooth (p < 0.001). For SA, the 8-year cumulative incident rate was 0.38% (95% CI: 0-0.79%) for implant fracture and 2.62% (95% CI: 0.05%-5.13%) for abutment fracture, which was influenced by implant diameter (p < 0.001) and site (p = 0.03). The cumulative implant/abutment fracture rate was lower for LA implants, particularly for LA implant-supported single crowns (SCs) (p < 0.05). The abutment-retrieval success rate was 92.8% for LA, and 57.1% for SA (p = 0.055).

CONCLUSION

LA implants exhibited a lower incidence of fracture in abutment-implant complexes and a relatively higher retrievability success rate for jammed abutments.

Clinical assessment of fractured implant abutment screws: The Bernese silicone replica technique

Fractured implant abutment screws can be retrieved with repair or rescue devices. However, whether the screw was completely retrieved or the inner implant body was damaged may be uncertain. A silicone replica technique was recently implemented in Bern and may be the most predictable method available at the moment for clinically assessing the internal implant body. This technique is straightforward and precise and may help dentists determine the internal implant condition when managing a fractured screw.