Evaluation of pre-tightening in abutments and prosthetic screws on different implant connections
Revista Odonto Ciência
Purpose: This study evaluated pre-tightening maintenance in abutment and prosthetic screws of external and internal hexagon implant with straight and angled abutments. Methods: Four groups of implants and abutments were assessed combining internal and external hexagon and straight and angled abutments, which were retained by titanium screws tightened to 20 N.cm. Crowns were retained with gold screws tightened at 10 N.cm. A vertical line was ascribed across the implant-abutment-crown interface
... t-crown interface to verify horizontal displacement by a light microscope. The fatigue tests were performed in a servo-hydraulic machine, which delivered forces between 100 and 120 N for 250,000 cycles. The screw was removed, and the detorque value was recorded. Data were analyzed with 2-way ANOVA and Tukey's test. Results: No horizontal displacement was observed on the interface of implant-abutment or abutment and crown. It was found significant difference for prosthetic screw between implant connection types, but without interaction with abutment. However, for abutment screw, there was a difference between implant connection types and abutment with interaction between implant and abutments. The straight abutment showed significant better performance than the 17° angled abutment. Conclusion: The connection implant types or abutment affected pre-tightening maintenance. Internal and external hexed connections were effective to avoid horizontal displacement of crowns.