This study aimed to utilize finite element analysis (FEA) to evaluate the primary stability of Cyroth dental implants (AoN Implants Srl, Grisignano di Zocco, Italy) under various biomechanical conditions, including different implant inclinations (0°, 15°, and 20°) and bone densities (D3 and D4). By comparing these results with those obtained from in vitro tests on polyurethane blocks, the study sought to determine whether FEA could provide stability information more quickly and efficiently than in vitro methods. The research involved correlating dental implant micro-mobility with the implant stability quotient (ISQ) using FEA to simulate the mechanical behavior of implants and the surrounding bone tissue. Additionally, the study assessed the error in ISQ value detection by comparing FEA results with in vitro tests on polyurethane blocks conducted under the same experimental conditions. Both the FEA simulations and in vitro experiments demonstrated similar trends in ISQ values. For the D3 bone block simulated by FEA, the difference from the in vitro test was only 1.27%, while for the D2 bone, the difference was 2.86%. The findings also indicated that ISQ increases with implant inclination and that bone quality significantly affects primary stability, with ISQ decreasing as bone density diminishes. Overall, this study showed that ISQ evaluation for dental implants can be effectively performed through FEA, particularly by examining micro-movements. The results indicated that FEA and in vitro polyurethane testing yielded comparable outcomes, with FEA providing a faster and more cost-effective means of assessing ISQ across various clinical scenarios compared to in vitro testing.

Optimizing stress distribution at the bone–implant interface is critical to enhancing the long-term biomechanical performance of dental implant systems. Vertical misalignment between splinted implants can result in elevated localized stresses, increasing the risk of material degradation and peri-implant bone resorption. This study employs three-dimensional finite element analysis (FEA) to evaluate the mechanical response of peri-implant bone under oblique loading, focusing on how variations in vertical implant platform alignment influence stress transmission. Four implant configurations with different vertical placements were modeled: (A) all crestal, (B) central subcrestal with lateral crestal, (C) lateral subcrestal with central crestal, and (D) all subcrestal. A 400 N oblique load was applied at 45° simulated masticatory forces. Von Mises stress distributions were analyzed in both cortical and trabecular bone, with a physiological threshold of 100 MPa considered for cortical bone. Among the models, configuration B exhibited the highest cortical stress, exceeding the physiological threshold. In contrast, configurations with uniform vertical positioning, particularly model D, demonstrated more favorable stress dispersion and lower peak values. Stress concentrations were consistently observed at the implant–abutment interface across all configurations, identifying this area as critical for design improvements. These findings underscore the importance of precise vertical alignment in implant-supported restorations to minimize stress concentrations and improve the mechanical reliability of dental implants. The results provide valuable insights for the development of next-generation implant systems with enhanced biomechanical integration and material performance under functional loading.

This study aimed to evaluate the biomechanical performance of two truncated cone implant designs in maxillary sinus lift (MSL) procedures using polyurethane laminas. A total of 128 implants were used. Polyurethane laminas were divided into two groups based on thickness (1 and 3 mm) and two subgroups based on density (20 and 30 pounds per cubic foot, PCF). Each subgroup tested two implants (Sinus-plant and Sinus Lift Concept: SLC), resulting in 8 experimental conditions and 16 implants per condition. The insertion torque (IT), removal torque (RT), and implant stability quotient (ISQ) were measured. SLC implants achieved significantly higher IT and RT across all tested conditions (p < 0.0001), reporting the highest values at the 30 PCF/3 mm lamina (IT: 34.09 ± 0.32 Ncm; RT: 32.15 ± 0.29 Ncm) and the lowest at the 20 PCF/1 mm lamina (IT: 11.86 ± 0.22 Ncm; RT: 10.28 ± 0.22 Ncm). Additionally, SLC implants achieved significantly higher ISQ values, ranging from around 61 to 48 ISQ. Notably, this difference was not significant at the 20 PCF/3 mm lamina, highlighting that bone density may play a more critical role than thickness for SLC implants. This study simulated the clinical condition of achieving primary stability even with extreme maxillary bone thickness. The findings indicate that while both implant designs can be utilized in MSL procedures, the SLC is particularly effective in scenarios with limited bone thickness and density, potentially allowing for simultaneous MSL, implant placement, and healing screw application.

Background/Objectives: This retrospective study assessed the accuracy of implant positioning with dynamic computer-aided implant surgery (dCAIS) for Toronto Bridge fabrication, using a conometric prosthetic concept and a new intraoral splinting technique (CLIKSS). It compared discrepancies across various anatomical regions, bone qualities, and implant sites. Methods: This study involved 52 patients undergoing full-arch rehabilitation (17 in the mandible, 30 in the maxilla, and 5 in both), with 366 implants placed (125 in the mandible, 241 in the maxilla; 128 in post-extraction sites, and the remainder in healed sites). All implants were immediately loaded. Precision was assessed by measuring linear and three-dimensional (3D) angular deviations between planned and actual implant positions. Results: Measurement errors for apical linear and 3D deviations at the apex and entry point ranged from 0.24 ± 0.10 to 0.55 ± 0.57 mm, and angular deviations varied from 0.32 ± 0.65° to 0.35 ± 0.71°. Maxillary measurements were significantly higher at the entry, apical, and vertical levels, even when comparing anterior and posterior regions with the corresponding mandibular areas, while no differences were found in the angular deviation. Significant discrepancies were observed among different mandibular bone types. Maxillary post-extraction sites exhibited significantly greater deviations than mandibular sites in all parameters except angular deviation. No significant differences were found between healed and post-extraction sites within the same jaw. Conclusions: dCAIS improved implant placement accuracy, leading to predictable prosthetic outcomes, especially during parallel multi-implant insertions. This report introduced dCAIS for conometric/biconometric implant placement combined with the innovative CLIKSS technique as an effective intraoral split method for this prosthesis connection.

Background/Objectives: The achievement of primary stability in low-density bone represents a critical endpoint in clinical practice. The aim of the present investigation was to evaluate the effectiveness of different drilling osteotomy techniques on polyurethane bone substitutes in vitro. Methods: A total of 320 osteotomies have been conducted on 10 pound per cubic feet (PCF) and 20PCF, respectively, with and without cortical layer. The simultaneous and progressive drilling protocol has been conducted at two different rotational speeds considering two different implant profiles (TAC conical vs. NT cylindrical implants). The study variables were insertion torque, removal torque, and resonance frequency analysis (RFA). Results: A significantly higher insertion torque, removal torque, and resonance frequency analysis RFA was detected at low speed with simultaneous drilling protocol (RPM) (p < 0.05). A TAC implant produced an increased implant stability compared to NT implants in all conditions tested (p < 0.05). Conclusions: The conical TAC implant showed higher implant stability in low-density polyurethane, and it is strongly recommended in critical bone quality. Simultaneous drilling osteotomy at low speed could further improve torquing positioning and significantly achieve primary stability in this condition.