Search Results (27)

Objective: This in vitro study evaluated the insertion torque characteristics of the KS 3 implant compared with the TSIII implant in standardized artificial bone models representing weak bone, extraction-socket-like reduced support, and maxillary sinus simulation conditions. Materials and Methods: A comparative in vitro study was performed using three models: a weak bone model, a standardized extraction-socket-like reduced-support model, and a maxillary sinus simulation model. Maximum and final insertion torque values were obtained from torque–depth curves. Torque–depth integrals were additionally calculated as exploratory secondary parameters. Statistical analyses were performed using Welch’s t-test and two-way ANOVA where appropriate, and the results were interpreted as exploratory because of the limited sample size. Results: The KS 3 implant showed higher maximum and/or final insertion torque values than the TSIII implant in the weak bone, extraction-socket-like, and maxillary sinus simulation models. In the maxillary sinus model, the torque values showed directional differences according to implant type and residual bone height under the tested fixed undersized drilling protocols for both CAS drilling and bone compaction drilling. Torque–depth integral analysis provided additional information regarding cumulative insertion resistance. Conclusions: Within the limitations of this controlled in vitro study, the KS 3 implant showed higher insertion torque values than the TSIII implant under the tested artificial bone conditions. These findings should be interpreted as in vitro insertion torque data under the tested artificial bone and drilling conditions, not as evidence of clinical superiority. In the maxillary sinus simulation model, the observed torque differences should be interpreted as the combined effect of implant macrodesign and the fixed undersized drilling protocol, rather than as an isolated macrodesign effect. Full article

Temporary anchorage devices (TADs) have become integral in contemporary orthodontic biomechanics, providing reliable skeletal anchorage independent of dental support or patient compliance. This narrative review synthesizes the current evidence regarding TADs classification, design parameters, biomechanical principles, clinical insertion protocols, complication management, and technological innovations. We reviewed foundational literature and recent clinical studies with emphasis on factors affecting primary and secondary stability, including insertion torque, angulation, cortical bone characteristics, and soft-tissue considerations. Self-drilling techniques are generally preferred for maxillary sites, while pre-drilling remains indicated in dense mandibular bone to reduce thermal risk and torque overload. Clinical success is optimized when insertion torque is maintained between 5 and 10 N·cm and site-specific anatomy is respected. Reported survival rates exceed 85–95% when proper protocols are followed. While TADs are associated with relatively low complication rates, failures are usually early and linked to excessive torque, poor hygiene, or inflammation. New technologies such as cone-beam computed tomography-guided placement, 3D-printed surgical guides, and AI-based planning tools offer promising avenues for safer and more individualized treatment. In conclusion, TADs represent a predictable and versatile option for skeletal anchorage in orthodontics, provided that mechanical design, biological adaptation, and clinical handling are coherently integrated into patient-specific strategies. Full article

Background/Objectives: In reverse shoulder arthroplasty (RSA), precise K-wire positioning of the glenoid component is critical to prevent complications such as glenoid loosening or instability as well as premature implant failure. Optimal component placement must adhere to individualized preoperative plans to account for patient-specific anatomical conditions. Conventional methods often fail to achieve this level of accuracy, undermining the need for personalized medicine. Intraoperative navigation systems are growing in use to improve accuracy in orthopedic surgery. This study aimed to compare the accuracy of K-wire positioning in a 3D-printed model of the scapula using conventional versus navigated methods. Methods: We recruited 20 participants: 10 experienced surgeons and 10 inexperienced medical students. Each participant performed four K-wire drillings—two with conventional instruments and two with an intraoperative navigation system. A novel target system, BoneTrack3D, was used to measure accuracy. We assessed the absolute deviation of the entry and exit points as well as the three-dimensional drilling angle. Results: The navigated method was significantly more accurate for all measured parameters at a family-wise significance level of α = 0.05. The median absolute deviation for the entry point was 1.6 mm with navigation versus 3.0 mm with the conventional method (p < 0.001). Similarly, the exit point deviation was 1.8 mm with navigation versus 6.7 mm conventionally (p < 0.001). The drilling angle deviation also showed significant improvement with navigation, at 2.6° compared to 8.9° conventionally (p < 0.001). However, the navigated method took longer, with a median drilling time of 100.0 s compared to 55.0 s for the conventional method (p < 0.001). The navigated method provided consistent and superior results regardless of a participant’s surgical experience. Conclusions: Navigated techniques for K-wire positioning in RSA demonstrate enhanced accuracy in a 3D-printed model, effectively executing a precise, patient-specific preoperative plan. This could be a direct contribution to personalized medicine, ensuring the final implant alignment is tailored to the individual’s anatomy. Furthermore, intraoperative navigation may contribute to a flatter learning curve, thereby increasing accessibility for surgeons with varying levels of experience. Although navigation introduces additional costs and longer initial procedure times, these drawbacks could be offset by improved technical outcomes and a reduced risk of complications. Future studies, including randomized clinical trials and cost-effectiveness analyses, should seek to validate these results in clinical settings with longer follow-up periods and larger patient cohorts to define long-term value and utility of navigation systems in reverse shoulder arthroplasty. Full article

Background: The morphology of implant threads plays a crucial role in achieving primary stability, which is essential for successful osseointegration and immediate loading of dental implants. This study aimed to evaluate how different implant thread pitches and an under-preparation drilling technique impact primary stability using an in vitro model. Methods: The study was conducted on low-density polyurethane bone models with and without cortical layers. The following three different implant thread profiles were tested: CYROTH 0.40 (0.40 mm), CYROTH 0.45 (0.45 mm), and CYROTH T (0.35 mm). Two different drilling procedures were utilized, with diameters of 3.4 mm and 3.7 mm, at a low rotational speed of 30 rpm. Primary stability was assessed by measuring insertion torque (IT), removal torque (RT), and resonance frequency analysis (RFA). Results: The low rotational speed of 30 rpm was found to be effective for achieving favorable fixation parameters in all scenarios. The 0.45 mm thread consistently exhibited higher implant stability quotient (ISQ) values (from two to six points higher) compared to the 0.40 mm and standard 0.35 mm threads, while also requiring lower IT. The highest ISQ values were recorded in the 20 pounds per cubic foot (PCF) block with a cortical layer using the 0.45 mm thread and a 3.4 mm drill. The under-preparation using the 3.4 mm drill resulted in higher IT and RT values than the 3.7 mm drill. Conclusions: This study demonstrated that implant thread pitch and drilling technique are critical factors influencing primary stability. Utilizing a wider thread pitch (0.45 mm) along with an under-preparation drilling protocol can significantly improve implant stability, even in low-density bone, without the need for excessive IT. These findings suggest that selecting the appropriate implant macrogeometry and surgical technique can optimize the primary stability of dental implants. Full article

Osseodensification (OD) compacts trabecular bone during implant site preparation rather than removing it, potentially enhancing primary stability versus conventional drilling. This review critically appraised clinical and preclinical evidence for OD’s biological and biomechanical efficacy in implant dentistry. We conducted electronic searches in seven databases (PubMed, Scopus, Web of Science, ScienceDirect, SciELO, LILACS, DOAJ) for the period January 2014 to March 2024. Studies comparing osseodensification with conventional drilling in clinical and large-animal models were included. Primary outcomes were insertion torque, implant stability quotient (ISQ), bone-to-implant contact (BIC), bone area fraction occupancy (BAFO), and complications. Of 75 retrieved records, 38 studies (27 clinical, 11 preclinical) provided analysable data. Based on descriptive averages from the narrative synthesis, osseodensification increased mean insertion torque by around 45% (range 32–59%) and initial ISQ by 3–10 units compared with conventional drilling. These gains permitted immediate loading in 78% of cases and shortened operating time (mean reduction 15–20 min). Animal studies demonstrated 12–28% higher BIC and increased peri-implant bone density at 4–12 weeks. No serious adverse events were recorded. Postoperative morbidity was similar between techniques. The collated evidence indicates that osseodensification significantly improves primary stability and may accelerate healing protocols, particularly in low-density (Misch D3–D4) bone. However, the predominance of short-term data and heterogeneity in surgical parameters limit definitive conclusions. Long-term randomised controlled trials with standardised protocols are needed before universal clinical recommendations can be established. Full article

Background: Primary implant stability is a critical factor for successful osseointegration and long-term implant success. This study investigates the impact of drilling protocol modifications on primary stability, considering different bone qualities and implant macro-designs, lengths, and diameters. Material and Methods: Three implant designs—two parallel-walled and one tapered—were tested with diameters ranging from 3.4 to 5.2 mm and lengths from 7.5 to 14.5 mm. Implants were placed in polyurethane foam blocks simulating different bone densities (10, 15, 25, and 35 PCF). A standard drilling protocol was used in all groups, with modifications based on bone quality: overpreparation in dense bone and underpreparation in softer bone. Primary stability was evaluated using insertion torque (IT). The optimal IT range was defined as 25–50 Ncm, based on clinical guidelines for immediate loading. The influence of drilling protocol adaptations on stability parameters was assessed. Results: Insertion torque was primarily influenced by bone density and implant diameter, with implant length playing a minor role. In dense bone (D1, D2), underpreparation improved torque values, especially in smaller implants, while overpreparation reduced them. The highest torques occurred with 5.2 mm implants, sometimes exceeding 80 Ncm. Standard protocols did not consistently achieve optimal torque across implant types. In soft bone (D3), underpreparation—particularly with tapered implants—was modestly beneficial. In very soft bone (D4), none of the protocols reliably reached the desired torque range. Conclusions: Adapting drilling protocols to bone density improves insertion torque, especially with wider implants and in denser bone. Underpreparation is generally more effective than overpreparation. However, in very soft bone, neither implant geometry nor drilling adaptations reliably achieve optimal primary stability, highlighting the need for additional strategies. Full article

Objective: To assess the bone histological changes and histomorphometric parameters when using different implant site preparation methods. Methods: A systematic search was conducted in March 2025 across the PubMed, Scopus, and Web of Science (WoS) databases following the PRISMA guidelines. An initial search of the databases yielded 338 potentially relevant articles. Ultimately, a total of 29 articles were included in the qualitative synthesis in this review. The considerable heterogeneity among the included studies precluded a meta-analysis. Results: This systematic review showed that, among all the assessed implant site preparation methods, which were drilling, laser, piezoelectric surgery, osteotomy and osteodensification, the classical drilling method was more likely to cause adverse changes at the drill site, such as microcracks, uneven bone margins, osteocyte damage and thermal injury. In contrast, alternative methods resulted in fewer microcracks, minimal inflammation, a reduced risk of thermal tissue damage and denser, more regular bone formation. When using these methods, the %BIC parameter was higher than when using the drilling method. Conclusions: Using alternative techniques to prepare the implant bed creates favourable conditions for proper healing and osseointegration by eliminating defects resulting from the drilling method. However, it should be noted that satisfactory results can be achieved using the classical method if the correct parameters of the drill rotation, cooling and load are employed. Further studies based on a uniform methodology are necessary to determine the most efficient and safest parameters for each method. Full article

Background/Objectives: Obliterates such as autologous bone dust (BD) or the synthetic bioactive glass S53P4 (BA) are frequently used for the obliteration of non-critical size defects (NCSDs), especially in otosurgery. Both obliterates have advantages and disadvantages, so that the combination of both for the obliteration of NCSDs is analysed. Methods: As part of a large animal project with sheep, four NCSDs were created in the calotte of thirteen animals using a drill. These were filled with BD, BD and BA, or BA, and the reference defect remained empty. After three weeks, the explanted calottes were examined with regard to their newly formed bone using digital volume tomography, bone density measurement, fluorochrome sequence labelling, and histological analysis. In addition, human cell culture analyses were carried out on the quality of the BD. Results: BD collected at 7.000 and 15.000 rpm shows a higher activity of new bone formation. In combination with BA, bone is formed centripetally and centrifugally. Defect filling with BA and BD shows a higher bone density and compactness than BD alone. Conclusions: BD should be harvested at a speed of less than 15.000 rpm. Using this BD in combination with BA to obliterate NCSDs enables the defect to be obliterated quickly and completely, with more newly formed bone, creating a bone network with incorporated BA. Further studies are needed to investigate the long-term stability of this obliteration and to determine which other parameters of the extraction can increase the amount of vital BD. Full article

Purpose: This study aimed to compare the histological characteristics of bone tissue following drilling with three implant systems under different rotational speeds and cooling conditions. Methods: A total of 54 implant bed preparations were performed in four swine ribs using three implant systems: Hiossen ET (Hiossen, Fairfield, NJ, USA), Paltop (Burlington, MA, USA), and Anyridge (Megagen, Daegu, Republic of Korea). Drilling was performed at three speeds (800, 1200, and 1500 rpm) under three cooling conditions: saline at room temperature, saline cooled to 4 °C, and no cooling. Histological evaluation was conducted using a Nikon Eclipse 80i fluorescence microscope (Nikon, Tokyo, Japan) with DAPI and rhodamine staining. Observations were performed at 40× magnification, focusing on the osteotomy wall and surrounding tissue. The samples were assessed based on surface smoothness, compressed tissue presence, carbonization, and adjacent tissue damage. Statistical analysis was performed using the Kruskal-Wallis test with Dunn’s post hoc comparisons to evaluate differences among experimental conditions. Results: The results demonstrated that the Hiossen ET system achieved optimal bone bed quality at 1200 rpm with saline cooling at 4 °C, producing the smoothest osteotomy walls and minimal thermal damage (p = 0.003). The Paltop system performed best at 800 rpm with 4 °C cooling, showing reduced tissue compression and fewer microcracks (p = 0.012). The Anyridge system exhibited the most favorable outcomes at 1200 rpm with saline cooling at room temperature, minimizing soft tissue remnants and preserving bone integrity (p = 0.021). Across all systems, the absence of cooling significantly increased thermal damage, carbonization, and tissue fragmentation, particularly at 1500 rpm (p < 0.001). Conclusions: The use of lower rotational speeds with effective cooling minimized tissue trauma and improved bone bed integrity. Further clinical validation is necessary to confirm the applicability of these results in human bone. Full article

Background/Objectives: This study investigates stress distribution in cancellous bone during pilot drilling for dental implants using the Cowper–Symonds model. Understanding the biomechanical effects of drilling parameters on bone health is essential for optimizing implant stability and longevity. Methods: A finite element analysis (FEA) approach was employed to simulate the pilot drilling process in cancellous bone. A three-dimensional jawbone model was developed from CT scan data, processed using 3D Slicer, and refined with CAD tools. The drilling simulation incorporated a rigid pilot drill and flexible cancellous bone, utilizing explicit dynamic methods. Stress distribution was evaluated for drilling depths ranging from 6 mm to 16 mm, with mesh density and strain rate effects considered to ensure accuracy. Results: The results showed an increase in stress levels with drilling depth, with maximum stress recorded at 16 mm. Initial contact stress was 17.3 MPa, rising to 228.9 MPa at deeper penetration due to increased interaction between the drill and bone. Stress distribution patterns emphasized the critical role of drilling depth and design parameters in mitigating bone damage. Conclusions: This study highlights the importance of optimized drilling protocols and pilot drill design to reduce stress and preserve bone integrity. The findings provide valuable insights into improving implant procedures and demonstrate the utility of FEA as a robust tool for evaluating biomechanical impacts during implant placement. Future research should incorporate cortical bone and thermal effects for a comprehensive analysis. Full article

Surgeons face a significant challenge due to the heat generated during drilling, as excessive temperatures at the bone–tool interface can lead to irreversible damage to the regenerative soft tissue and result in thermal osteonecrosis. While previous studies have explored the use of machine learning to predict the temperature rise during bone drilling, this in vitro study introduces a comprehensive approach by combining the Response Surface Methodology (RSM) with advanced machine learning techniques. The main objective lies in the comprehensive evaluation and comparison of support vector machine (SVM) and random forest (RF) models specifically for the optimization of the bone drilling parameters to prevent thermal bone necrosis. A total of 27 experiments were conducted using a multi-level factorial method, with analysis performed via the Minitab software version 19.1. Performance metrics such as the mean squared error (MSE), mean absolute percentage error (MAPE), and coefficient of determination (R²) were used to assess model accuracy. The RF model emerged as the most effective, with R² values of 94.2% for testing and 97.3% for training data, significantly outperforming other models in predicting temperature fluctuations. This study demonstrates the superior predictive capabilities of the RF model and offers a robust framework for the optimization of surgical procedures to mitigate the risk of thermal damage. Full article

In orthopedics, bone drilling is a crucial part of a surgical method commonly carried out for internal fixation in bone fracture treatment. The primary purpose of bone drilling is the creation of holes for screw insertion to immobilize fractured parts. The bone drilling task depends on the orthopedist and surgeon’s high level of skill and experience. This paper aimed to provide a summary of previously published review studies in the field of bone drilling. This review paper also presents a comprehensive review of the application of machine learning for bone drilling and as a future direction for automation systems. This review can also help medical surgeons and bone drillers understand the latest improvements through parameter selection and optimization strategies to reduce bone damage in bone drilling procedures. Apart from the review, bone drilling vibration data collected in a university laboratory experiment is also presented in this study. The vibration data consist of three different layers of femur cow bone, which are processed and classified using several deep learning (DL) methods such as long short-term memory (LSTM), convolutional neural network (CNN), and recurrent neural network (RNN). These DL methods are used in the bone drilling lab case study to prove that the layers of bone drilling are associated with the vibration signal and that they can be classified and predicted using DL methods. The result shows that LSTM is outperformed by CNN and RNN. Full article

Mechanical and thermal trauma during implant surgery may be reasons for initial peri-implant bone loss. Temperature development during drilling and implant insertion were quantified in this series of in vitro and animal experiments. Polyurethane foam material mimicking different classes of alveolar bone was used as a model material for simulating implant surgery. Using thermocouples, temperature development was determined in the model material at depths of 3 mm and 10 mm during site preparation and implant insertion. Additionally, an infrared camera allowed for measuring drill temperatures both in vitro and as part of an animal trial using an intraoral minipig model. Drill diameter and repeated usage of drills did not have a major effect on temperature generation. The addition of a diamond-like carbon coating, bone density, predrilling, and irrigation heavily affected intraosseous temperatures. In vivo, applying regular drill protocols, an intraosseous temperature rise of approximately 3 °K was determined. Implant geometry as well as the amount of undersizing of an osteotomy governed heat generation during implant insertion. Drill protocols and the amount of undersizing of an implant osteotomy constitute parameters by which clinicians can limit trauma during implant surgery. Full article

Bone drilling is a common procedure used to create pilot holes for inserting screws to secure implants for fracture fixation. However, this process can increase bone temperature and the excessive heat can lead to cell death and thermal osteonecrosis, potentially causing early fixation failure or complications. We applied a three-dimensional dynamic elastoplastic finite element model to evaluate the propagation and distribution of heat during bone drilling and assess the thermally affected zone (TAZ) that may lead to thermal necrosis. This model investigates the parameters influencing bone temperature during bone drilling, including drill diameter, rotational speed, feed force, and predrilled hole. The results indicate that our FE model is sufficiently accurate in predicting the temperature rise effect during bone drilling. The maximum temperature decreases exponentially with radial distance. When the feed forces are 40 and 60 N, the maximum temperature does not exceed 45 °C. However, with feed forces of 10 and 20 N, both the maximum temperatures exceed 45 °C within a radial distance of 0.2 mm, indicating a high-risk zone for potential thermal osteonecrosis. With the two-stage drilling procedure, where a 2.5 mm pilot hole is predrilled, the maximum temperature can be reduced by 14 °C. This suggests that higher feed force and rotational speed and/or using a two-stage drilling process could mitigate bone temperature elevation and reduce the risk of thermal osteonecrosis during bone drilling. Full article

Bone density at the implant site is correlated to the success of osseointegration. The objective of this in vitro study was to evaluate the efficacy of osseodensification burs in increasing bone density using a solid polyurethane foam block model. The osseodensification burs kit was used to perform 48 osteotomies on a rigid polyurethane foam test ground. Burs were utilized on a TMM2 implant motor for data collection. The osteotomies were divided into two study groups (A and C) in which implant sites, extended 12 and 14 mm deep, respectively, were prepared using the drills to a compaction rotation; two control groups, B and D, represented the osteotomies for which the drills were used in cutting direction. A 3.8 × 12 mm conical implant was inserted into each site; for each implant, data were collected on the peak torque (Cp), mean torque (Cm), and integral depth curve (I). The implants underwent resonance frequency analysis (RFA) to assess the implant stability quotient (ISQ). Correlation analysis was performed between I, Cm, Cp and ISQ. One-way analysis of variance (ANOVA) was used to identify statistically significant differences between groups. Group C, representing osteotomies prepared at 14 mm with osseodensification burs, showed a significantly higher value for each parameter. Implants at sites obtained with osteocondensation drills and prepared at greater depth for autologous particle grafting showed significant increases in each implant stability parameter. Full article