RESUMO
The aim of this study is to assess the stress distribution on the bone tissue and bone-implant interface of a customized anatomic root-analog dental implant (RAI) by means of finite element analysis (FEA) for different types of bone density. A mandibular right second premolar was selected from the CBCT database. A DICOM file was converted to an STL file to create a CAD model in FEA software. The bone boundary model was created, while bone density types I-IV were determined. Von Mises stress was measured at bone tissues and bone-implant interfaces. To validate the models, the RAI was 3D printed through a laser powder-bed fusion (L-PBF) approach. The results revealed that all RAI designs could not cause plastic deformation or fracture resulting in lower stress than the ultimate tensile stress of natural bone and implant. Compared to a conventional screw-type implant, RAIs possess a more favorable stress distribution pattern around the bone tissue and the bone-implant interface. The presence of a porous structure was found to reduce the stress at cancellous bone in type IV bone density.
RESUMO
Background/purpose: Bioceramic tetracalcium phosphate (TTCP) is used as a surface modifier on the implant surface and the clinical studies on this surface modification are still limited. The objective of this clinical study was to investigate short-term implant stability of titanium implant surfaces being modified through sandblasting and acid etching (SLA), followed by TTCP sintered bioceramic anchoring. Materials and methods: A total of 20 patients who had single tooth space were included in this study. Surface modification by SLA plus with TTCP on Ti implants with a diameter of 4.0 mm and lengths of 10 and 11.5 mm were placed. Implant stability quotient (ISQ) value was measured immediately (ISQ0) and one month (ISQ1), two months (ISQ2), three months (ISQ3), and four months (ISQ4) after implantation. Subgroup analysis was defined to location (maxilla, mandible) and bone density (soft or hard bone). Statistical analysis was performed using Friedman test and Mann-Whitney U test. Results: The mean ISQ values with standard deviation at the different time points of ISQ0 to ISQ4 were 60.03 ± 14.12, 53.48 ± 15.24, 58.91 ± 14.43, 63.14 ± 12.22, and 63.50 ± 13.61, respectively. The results showed significant differences between the ISQ1 and ISQ3 groups and between the ISQ1 and ISQ4 groups. On the other hand, there was no statistical differences between the maxilla and mandible as well as between soft and hard bone types in all implant groups. Conclusion: TTCP/titanium implant showed favorable stability in short-term ISQ values over 4 months. The locations and bone types demonstrated no effect on implant stability.