Peri‐implant bone alterations under the influence of abutment screw preload stress. A preclinical vivo study
| Autor: | Masako Nagasawa, Mubarak Suliman, Ameen Khraisat, Farah Alomari, Katsumi Uoshima |
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| Rok vydání: | 2020 |
| Předmět: |
Dental Stress Analysis
Bone Screws 0206 medical engineering Dental Abutments 02 engineering and technology Bone and Bones Osseointegration Bone remodeling 03 medical and health sciences 0302 clinical medicine medicine Animals Dental Implants Orthodontics business.industry Dental Implant-Abutment Design 030206 dentistry 020601 biomedical engineering Preload medicine.anatomical_structure Torque Cortical bone Rabbits Stress Mechanical Implant Bone marrow Oral Surgery business Abutment (dentistry) Abutment Screw |
| Zdroj: | Clinical Oral Implants Research. 31:1232-1242 |
| ISSN: | 1600-0501 0905-7161 |
| Popis: | Objectives The study purpose was to examine peri-implant bone alternations around osseointegrated implants caused solely by abutment screw preload stress using different tightening torque values. Materials and methods Twenty 20- to 22-week-old Japanese white rabbits received two implants each in right and left femurs. Implants were randomly assigned to one of three tightening torque groups or the control (Cont) group. After 8 weeks, 35 Ncm torque was delivered to abutment screws in the recommended torque (RT) group (n = 16). Other screws received 70 Ncm torque as the high torque (HT) group (n = 16). Temporary tightening (TT) groups (n = 8) received only 70 Ncm torque without preload stress as screws were untightened immediately. Cont group (n = 40) remained in situ. Animals were euthanized at 4, 6, 8, and 10 weeks after torque application. Micro-CT images were then taken, and undecalcified ground sections were stained with toluidine blue. Results Cross-sections of cortical bone showed remodeling activities adjacent to the implant in all groups. While bone marrow spaces appearance was relatively small in Cont and TT groups, RT and HT groups showed large bone marrow spaces and extensive remodeling activity. Bone-to-implant contact was significantly less in RT and HT groups compared with Cont and TT groups at different time points (p ˂ .05). Furthermore, RT and HT groups showed significantly less bone volume and area (p ˂ .05). Conclusion Results suggested that preload stress without any occlusal loading might negatively affect peri-implant bone stability and initiate bone remodeling. This could alter bone mechanical properties, subsequently influencing long-term implant success. |
| Databáze: | OpenAIRE |
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