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Effect of cyclic loading and retightening on reverse torque value in external and internal implants
Woong-Rae Cho1, Yoon-Hyuk Huh1, Chan-Jin Park1
1Department of Prosthodontics and Research Institute of Oral Science, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea.
The Journal of Advanced Prosthodontics
|September 3, 2015
Summary
Screw retightening is crucial for maintaining implant stability, especially in internal type implants, to prevent loss of reverse torque value (RTV) under cyclic loading. Early retightening is recommended for optimal implant function.
Area of Science:
- Dental Implantology
- Biomaterials Engineering
- Mechanical Engineering
Background:
- Implant screw loosening is a common complication in dental restorations.
- Reverse Torque Value (RTV) is a critical parameter for assessing implant screw stability.
- Understanding factors affecting RTV is essential for long-term implant success.
Purpose of the Study:
- To investigate the impact of cyclic loading and screw retightening on RTV.
- To compare the RTV behavior of external versus internal type dental implants.
- To determine the optimal retightening protocol for maintaining implant stability.
Main Methods:
- Cement-retained abutments were torqued to 30 Ncm on external and internal implants.
- Experimental groups were subjected to 100,000 cycles of loading.
- RTV was measured at various intervals, with and without screw retightening protocols.
Main Results:
- All groups exhibited a decrease in RTV after cyclic loading.
- External type implants consistently showed higher RTVs than internal type implants.
- Screw retightening effectively maintained RTV in internal implants but not in external implants.
Conclusions:
- Screw retightening is more beneficial for internal type implants compared to external type implants.
- Implementing screw retightening early in the functional loading phase is recommended.
- This finding has significant implications for optimizing dental implant maintenance protocols.
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