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Preload evaluation of different screws in external hexagon joint
Wirley Gonçalves Assunção1, Juliana Aparecida Delben, Lucas Fernando Tabata
1Department of Dental Materials and Prosthodontics, Araçatuba Dental School, Universidade Estadual Paulista (UNESP), Araçatuba, São Paulo, Brazil. wirley@foa.unesp.br
Implant Dentistry
|January 10, 2012
Summary
Titanium alloy retention screws maintained the most torque for implant-supported crowns. Gold alloy and aluminum titanium nitride coated screws showed the lowest torque retention.
Area of Science:
- Dental Implantology
- Biomaterials Science
- Prosthodontics
Background:
- Retention screw stability is crucial for the longevity of implant-supported crowns.
- Understanding torque maintenance in different screw materials is essential for clinical success.
Purpose of the Study:
- To compare the torque maintenance of various retention screw types used in implant-supported crowns.
- To evaluate the influence of different coatings on screw retention.
Main Methods:
- Twelve UCLA abutment-supported metallic crowns (cobalt-chromium) were tested on osseointegrated implants.
- Four groups of retention screws were used: titanium alloy, gold alloy with gold coating, titanium alloy with diamond-like carbon film, and titanium alloy with aluminum titanium nitride coating.
- Detorque measurements were taken after initial torque insertion and analyzed using ANOVA and Tukey's tests.
Main Results:
- All tested retention screws exhibited a reduction in torque over time.
- The titanium alloy retention screw (Group A) demonstrated the highest percentage of torque maintenance.
- Gold alloy (Group B) and aluminum titanium nitride coated titanium alloy (Group D) screws showed the lowest torque retention, with no significant difference between them.
Conclusions:
- All retention screw types experience a decrease in torque.
- Titanium alloy screws offer superior torque maintenance compared to coated variants.
- Gold-coated and aluminum titanium nitride coated titanium screws exhibit the least torque stability.
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