Trephination-based autonomous robotic surgery for dental implant placement: A proof of concept.

OBJECTIVES: To present a novel drilling protocol of trephine osteotomy technique for autologous bone grafting with simultaneous implant placement using an autonomous robotic system. METHODS: The novel protocol consists of 1) preoperative procedures: marker fabrication and fixation, data acquisition, and preoperative planning; 2) intraoperative procedures: registration and calibration, and osteotomy and implant placement performed by an autonomous dental implant robot; 3) postoperative procedures: CBCT acquisition and accuracy assessment. RESULT: The protocol was an effective method for implant osteotomy, with no reported intraoperative complications. The implant surgery was successfully completed, and autogenous bone was obtained. Meanwhile, the accuracy of implant placement was clinically acceptable, with minor deviations. CONCLUSIONS: Trephination-based robotic surgery can be successfully implemented in implant osteotomy, which might replace freehand implant surgery and conventional drilling protocol. However, further clinical studies are necessary. CLINICAL SIGNIFICANCE: The main finding of this case is a potential alternative for preserving autogenous bone during implant surgery.

Measurement of Implant Insertion Torque in Intentionally Undersized Osteotomy Site Preparation in the Posterior Maxilla: A Prospective Clinical Study.

Achieving adequate primary stability for dental implants in the posterior maxilla is challenging due to the area's low bone density and fine trabecular bone. Low primary implant stability can compromise the long-term success of the implant. This study aims to evaluate the effect of intentionally undersized osteotomy sites on the insertion torque of implants placed in type 4 bone density in the posterior maxilla, regardless of the surgeon's tactile sense of the bone density. The conventional implant placement technique was performed in the posterior maxilla by intentionally omitting the last drill of the recommended drilling sequence protocol. The insertion torque was measured using an integrated surgical motor software. The study included 72 implants in patients of both genders and different age groups. The retrieved samples were divided into four groups, with insertion torque ranging from 11 Ncm to 48 Ncm. The mean insertion torque was 26.51 ± 0.18 Ncm for all cases (P = .001). No significant difference was found in the mean insertion torque between different age groups (26.51 ± 2.845, P = .84). However, a significant difference was observed between male and female cases (P = .84). Most implant insertion torque measurements vary significantly between cases in the intentionally underprepared posterior maxillary osteotomy site. The last drill should be omitted for all preparations of the posterior maxillary implant sites. Intentionally minimizing the osteotomy site is recommended for all posterior maxillary implant cases.

Influence of Bone Quality, Drilling Protocol, Implant Diameter/Length on Primary Stability: An In Vitro Comparative Study on Insertion Torque and Resonance Frequency Analysis.

The aim of this study was to evaluate the influence of bone quality, drilling technique, implant diameter, and implant length on insertion torque (IT) and resonance frequency analysis (RFA) of a prototype-tapered implant with knife-edge threads. The investigators hypothesized that IT would be affected by variations in bone quality and drilling protocol, whereas RFA would be less influenced by such variables. The investigators implemented an in vitro experiment in which a prototype implant was inserted with different testing conditions into rigid polyurethane foam blocks. The independent variables were: bone quality, drilling protocol, implant diameter, and implant length. Group A implants were inserted with a conventional drilling protocol, whereas Group B implants were inserted with an undersized drilling protocol. Values of IT and RFA were measured at implant installation. IT and RFA values were significantly correlated (Pearson correlation coefficient: 0.54). A multivariable analysis showed a strong model. Higher IT values were associated with drilling protocol B vs A (mean difference: 71.7 Ncm), implant length (3.6 Ncm increase per mm in length), and substrate density (0.199 Ncm increase per mg/cm3 in density). Higher RFA values were associated with drilling protocol B vs A (mean difference: 3.9), implant length (1.0 increase per mm in length), and substrate density (0.032 increase per mg/cm3 in density). Implant diameter was not associated with RFA or IT. Within the limitations of an in vitro study, the results of this study suggest that the studied implant can achieve good level of primary stability in terms of IT and RFA. A strong correlation was found between values of IT and RFA. Both parameters are influenced by the drilling protocol, implant length, and substrate density. Further studies are required to investigate the clinical response in primary stability and marginal bone response.

Definition of a drilling protocol for mini dental implants in different bone qualities.

Mini dental implants (MDI) have proven to be a good alternative of the conventional implants to support lower overdentures in elderly edentulous patients with narrow residual ridge. The aim of the present study was to define drilling protocols for each diameter of the MDI in each bone quality. The number and the diameter of the drilling bur and the drilling depth was investigated. A total of 48 MDIs with a ball head and transgingival collar were used to the drilling protocol in four different bone qualities (Q1-Q4). All available four diameters of the implants were included: 1.8mm, 2.1mm, 2.4mm, and 2.9mm. The length of all implants was 15mm. Three different protocols were prepared for each of the four bone qualities and for each implant diameter. The insertion torques and the primary stability of the implants were measured in their final position. Regardless of implant diameter and bone quality, the insertion torque was significantly higher using drilling protocol 1 than 3 and using drilling protocol 2 than 3 as well. The insertion torque was significantly higher in bone quality Q1 than in Q2-Q4. The unscrewing resulted in considerably increase in the torque, which exceeded the insertion torques by up to two times. This repeatedly led to the bending and fractures of implants.

Modified surgical drilling protocols influence osseointegration performance and predict value of implant stability parameters during implant healing process.

OBJECTIVE: The aim of this study was to evaluate the effects of three different surgical drilling protocols on changes of implant stability parameters and osseointegration performance during the healing period in rabbit femoral condyles. MATERIAL AND METHODS: Thirty New Zealand white rabbits were used in this study. Three experimental groups according to different surgical drilling protocols (undersized, standard and oversized preparation) were designed. Measurements of implant stability parameters were performed immediately after implant insertion and then at 1, 2, 4, and 8 weeks after the operation. After the animals were sacrificed, the bone blocks with implant were prepared for histological evaluation and histomorphometric analysis. RESULTS: The results demonstrated that the ISQ values of each group increased gradually through the whole healing period, while the damping factor showed the opposite tendency. The histomorphometric analysis revealed that BIC (bone-implant contact) values gradually increased with time until 8 weeks of healing at each group. In addition, the undersized group has the highest initial BIC (25.16% ± 7.25%) and the lowest values were found in oversized group (9.13% ± 5.89%). Moreover, a higher correlation (R2 = 0. 9817) between ISQ and BIC values in oversized group and moderate correlations between DF and BIC values in undersized group (R2 = 0.823) were demonstrated. CONCLUSIONS: The undersized drilling protocol group presented the highest implant stability and BIC values in the whole healing period, while the similar tendency of results was found between standard and oversized drilling protocol groups. CLINICAL RELEVANCE: These results suggested that undersized drilling protocol is mechanically and biologically beneficial in low-density bone. The modifications of surgical drilling protocols would influence the predictive value of implant stability parameters for osseointegration performance.

Evaluation of implant stability using different implant drilling sequences.

BACKGROUND/PURPOSE: Simplifying the drilling sequence would be meaningful for implant surgery, if it does not exert a negative influence. This prospective clinical study was conducted to evaluate the stability of implant placements after simplifying the drilling sequence. MATERIALS AND METHODS: Subjects were divided into a control group that underwent a normal drilling sequence or a test group that underwent only an initial and final drilling. To evaluate the stability of the placed implant, radiography and implant stability quotient (ISQ) measurements were recorded immediately and 5 months after placement. RESULTS: In all subjects, the prosthesis process was completed with no significant resorption of the marginal bones. In contrast, a statistically significant difference was observed between the control and test groups 5 months after the implants were placed in terms of the ISQ score (80.72 ±â€¯6.76 and 71.83 ±â€¯9.00, respectively); however, both scores were sufficient to proceed with the prosthesis process. CONCLUSION: These attempts to simplify drilling protocols are expected to contribute the improvement of implant-related treatments in future.

Effect of low speed drilling on osseointegration using simplified drilling procedures.

Our aim was to find out whether simplified drilling protocols would provide biological responses comparable to those of conventional drilling protocols at the low rotational speed of 400rpm. Seventy-eight root form endosseous implants with diameters of 3.75, 4.2, and 5mm were placed into canine tibias and allowed to heal for 3 and 5 weeks. After the dogs had been killed, the samples of implanted bone were retrieved and processed for non-decalcified histological sectioning. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) analyses were made on the histological sections. Implants treated by the simplified protocol resulted in BIC and BAFO values comparable to those obtained with the conventional drilling protocol, and there were no significant differences in the technique or diameter of the drilling. The results suggest that the simplified procedure gives biological outcomes comparable to those of the conventional procedure.