Comparative assessment of the stability of buccal shelf mini-screws with and without pre-drilling- a split-mouth, randomized controlled trial.

OBJECTIVES: To examine and compare the stability of buccal shelf mini-screws using self-drilling and pre-drilling implant placement techniques. METHODOLOGY: It was a split-mouth, randomized controlled trial comprising of 7 patients, each receiving two buccal shelf bone screws. The screws were placed using a self-drilling protocol in one quadrant and a pre-drilling protocol in the opposing quadrant decided via coin toss randomization. Stability was examined at the time of placement and 1,2, 3 and 4 months thereafter, using the Resonance Frequency Analysis method with the Osstell Beacon TM device. The Implant Stability Quotient (ISQ) obtained was then compared and assessed between both quadrants. Friedman's Two-Way Analysis of Variance and the Wilcoxon signed rank test were utilized for the intergroup comparison. A statistically significant result was defined as one with a p-value of less than 0.05. RESULTS: A statistically significant difference between the mean ISQ reading in the pre-drilling and self-drilling group was observed, indicating higher stability of bone screws placed with the pre-drilling protocol. The primary stability of the buccal shelf screws decreased after placement, but the secondary stability remained stable. CONCLUSION: Buccal shelf bone screws placed with a pre-drilling protocol depicted greater primary and secondary stability as compared to the self-drilling protocol, as depicted by the ISQ readings obtained. Resonance Frequency Analysis can be used as a valuable tool to assess the stability of buccal shelf bone screws. CLINICAL RELEVANCE: The use of buccal shelf screws has increased tremendously over the past few years due to their myriad applications and have now become an essential part of an orthodontist's armamentarium. It is therefore essential for clinicians to be well-informed about all aspects of their use including insertion techniques. The results of this trial indicate that the pre-drilling protocol provides better stability and therefore treatment outcomes.

Thermal implant removal in a pig jaw: a proof of concept study.

OBJECTIVES: The aim of this study was to evaluate whether thermal implant removal of osseointegrated implants is possible using a diode laser with an specific temperature-time interval. MATERIALS AND METHODS: First, tooth extraction of the first three premolars was performed in the maxilla and mandible on both sides of 10 pig. After 3 months, implants were inserted into the upper and lower jaws of 10 pigs. After 3 more months, osseointegrated implants were heated with a laser device to a temperature of 50 °C for 1 min. After 14 days, the implant stability quotient (ISQ), torque-out values, and bone-to-implant contact (BIC) ratio were assessed using resonance frequency analysis. RESULTS: ISQ values showed no significant differences within each group or between the control and test groups. Furthermore, torque-out and BIC value measurements presented no significant differences between the groups. CONCLUSIONS: At 50°C, changes in the BIC values were noticeably smaller; however, these differences were not significant. Future studies should evaluate the same procedures at either a higher temperature or longer intervals. CLINICAL RELEVANCE: With only 50 °C for 1 min, a dental implant will not de-integrate predictably.

Mandibular overdentures retained by 1 or 2 implants: a 5-year randomized clinical trial on implant stability and peri-implant outcomes.

AIM: This is a report of the 5-year results of a two-group parallel randomized clinical trial comparing longitudinal implant stability, and clinical and radiographic peri-implant outcomes of mandibular overdentures retained by one (1-IOD group) or two (2-IOD group) implants. METHODS: All participants received 4.1 mm diameter tissue-level implants (Straumann® Standard Plus - SLActive®, Institut Straumann AG), installed in the mandible midline (1-IOD; n = 23) or the lateral incisor-canine area bilaterally (2-IOD; n = 24), and loaded after 3 weeks. Implant Stability Quotient (ISQ) was measured using a resonance frequency device (Osstell® Mentor, Integration Diagnostics) at implant placement, after three weeks (loading), and at the 6-month, 1-, 3-, and 5-year follow-ups. Marginal bone loss and clinical implant outcomes (plaque, calculus, suppuration and bleeding) were assessed periodically up to 5 years after loading. RESULTS: Only minor changes in marginal bone level were observed after 5 years (mean = 0.37; SD = 0.44 mm), and satisfactory and stable peri-implant parameters were observed throughout the 5-year follow-up. No significant differences between groups were found. Overall, the mean primary implant stability was considered high (> 70) for the two groups (1-IOD = 78.1 ± 4.5; 2-IOD = 78.0 ± 5.8). No noticeable changes were observed between implant insertion and loading. A marked increase was observed from insertion to the 6-month follow-up - the mean difference for the 1-IOD group was + 5.5 ± 5.5 (Effect size = 1.00), while for the 2-IOD group, the mean difference was + 6.0 ± 5.6 (Effect size = 1.08). No relevant changes were observed throughout the follow-up periods up to 5 years. Linear mixed-effect model regression showed no influence of the bone-related variables (p > 0.05) and the number of implants (p = 0.087), and a significant effect of the time variable (p < 0.001). CONCLUSION: Satisfactory peri-implant outcomes and stable secondary stability suggest good clinical performance and successful long-term osseointegration of the implants for single and two-implant mandibular overdentures. Using a single implant to retain a mandibular overdenture does not seem to result in detrimental implant loading over the five years of overdenture use. CLINICAL RELEVANCE: This study corroborates the use of a single implant to retain a mandibular denture.

Is Acoustic modal analysis a reliable substitution for Osstell® device in dental implant stability assessment? An experimental and finite element analysis study.

BACKGROUND: Different methods have been proposed to investigate the fixation stability of dental implants, each of which has its limitations. Among these methods, resonance frequency analysis (RFA) has been widely utilized to measure dental implant stability. This study aimed to assess dental implants with two non-destructive RFA and acoustic modal analysis (AMA) validated with a finite element simulation of the fundamental natural frequency (NF) of the bone analog-implant structure. MATERIAL AND METHODS: A total number of 18 implants were inserted into two Polyurethane (PU) bone blocks with different densities (0.16 g/cc and 0.32 g/cc). AMA was used to measure NF; First, the sound originating from the axial tapping of the implant was recorded with a simple microphone. Secondly, a fast Fourier transformation algorithm was conducted to determine the NF of the implant-bone analog structure. In parallel, the ISQ (Implant Stability Quotient) value was measured using the Osstell® device. Finally, using finite element analysis (FEA), the implant-bone analog structure was modeled for validation. RESULTS: Doubling the bone analog density resulted in an average increase of 82% and 47% in the NF and ISQ using AMA and Osstell®, respectively (P-value<0.05). Furthermore, a strong linear relationship (R2= 0.93) was observed between the measured NF and ISQ values in the linear regression analysis. The NF of the dental implant predicted by FEA was overestimated by about 15.2% and 15.0% than those in the low- and high-density PUs, respectively. Moreover, the FEA predicted an increase of 83% in NF by increasing the bone analog density from 0.16 to 0.32 g/cc. CONCLUSIONS: Having required the minimum process combined with easily available equipment makes it an ideal method for fixation strength studies. The good correspondence between the ISQ values and NFs, in addition to the good accuracy and reliability of the later method, confirms its application for fixation stability assessment.

Comparing Implant Macrodesigns and Their Impact on Stability: A Year-Long Clinical Study.

Background and Objectives: The aim of this study was to clinically evaluate the primary and secondary stability of dental implants with different macrodesigns using resonance frequency analysis and to determine whether implant design and length influence implant stability. Materials and methods: This study included 48 healthy patients receiving dental implants, and a pre-implant planning protocol was used, which involved detailed bone analysis, clinical examinations, and Cone beam computed tomography (CBCT) analysis. The implants were of various types and dimensions (Alpha-Bio Tec (Israel), DFI, SPI, and NEO), and the surgical procedures were performed using standard methods. Implant stability was measured using resonance frequency analysis (RFA) immediately after placement and after 3, 6, and 12 months. The total number of implants placed in all patients was 96. Results: The average primary stability value for 10 mm SPI implants placed in the maxilla was 68.2 ± 1.7 Implant Stability Quotient (ISQ) units, while for 10 mm NEO implants, it was 74.0 ± 0.9. The average primary stability value for a 10 mm DFI implant placed in the mandible was 72.8 ± 1.2 ISQ, while for a 10 mm NEO implant placed in the mandible, it was 76.3 ± 0.8 ISQ. Based on the Friedman ANOVA test, the differences in the stability measurements for the 10 mm and 11.5 mm SPI implants and for the 10 mm and 11.5 mm NEO implants in the maxilla on day 0 and after 3, 6, and 12 months were significant at p < 0.05. Similarly, based on the Friedman ANOVA test, the differences in the stability measurements for the 10 mm and 11.5 mm DFI implants and for the 10 mm and 11.5 mm NEO implants in the mandible on day 0 and after 3, 6, and 12 months were significant at p < 0.05 (p = 0.00000). Conclusions: Universal tapered implants of the NEO type stood out as the optimal choice, as they provided statistically significantly higher primary stability in both soft and hard bone types compared to other implants. The implant length did not significantly affect this stability.

The influence of truncated-conical implant length on primary stability in maxillary and mandibular regions: an in vitro study using polyurethane blocks.

OBJECTIVES: This in vitro study is aimed at assessing whether implant primary stability is influenced by implant length in artificial bone with varying densities. MATERIALS AND METHODS: A total of 120 truncated-conical implants (60 long-length: 3p L, 3.8 × 14 mm; 60 short-length: 3p S, 3.8 × 8 mm) were inserted into 20, 30, and 40 pounds per cubic foot (PCF) density polyurethane blocks. The insertion torque (IT), removal torque (RT), and resonance frequency analysis (RFA) values were recorded for each experimental condition. RESULTS: In 30 and 40 PCF blocks, 3p S implants exhibited significantly higher IT values (90 and 80 Ncm, respectively) than 3p L (85 and 50 Ncm, respectively). Similarly, RT was significantly higher for 3p S implants in 30 and 40 PCF blocks (57 and 90 Ncm, respectively). However, there were no significant differences in RFA values, except for the 20 PCF block, where 3pS implants showed significantly lower values (63 ISQ) than 3p L implants (67 ISQ) in both the distal and mesial directions. CONCLUSIONS: These results demonstrated that the implant's length mainly influences the IT and RT values in the polyurethane blocks that mimic the mandibular region of the bone, resulting in higher values for the 3p S implants, while the RFA values remained unaffected. However, in the lowest density block simulating the maxillary bone, 3p L implants exhibited significantly higher ISQ values. CLINICAL RELEVANCE: Therefore, our data offer valuable insights into the biomechanical behavior of these implants, which could be clinically beneficial for enhancing surgical planning.

Influence of different surgical techniques on primary implant stability in the posterior maxilla: a randomized controlled clinical trial.

BACKGROUND AND OBJECTIVE: Primary stability (PS) is remarkable for secondary stability and implant success. Surgical technique modifications seem to improve primary stability, especially in poor quality bone. The aim of this study was to compare the insertion torque (IT) and implant stability quotients (ISQ) of implants placed with underpreparation, expanders, and standard surgical instrumentation in different bone types. MATERIAL AND METHODS: This randomized controlled clinical trial enrolled 108 patients (n=108 implants) distributed in three study groups: group 1 (n=36) underpreparation technique, group 2 (n=36) expander technique, and group 3 (n=36) conventional drilling. IT was recorded with a torque indicator. ISQ was recorded with resonance frequency analysis immediately after surgery. RESULTS: ISQ values were associated with the patient's bone quality and were higher in bone quality type II (76.65) and type III (73.60) and lower in bone quality type IV (67.34), with statistically significant differences (p<0.0001). Lower stability results were obtained when conventional drilling (69.31) was used compared to the use of underpreparation (74.29) or expanders (73.99) with a level of significance of p=0.008 and p=0.005, respectively. CONCLUSIONS: The surgical technique influences the PS when there is low-quality bone. In low-quality bones, conventional drilling obtains lower ISQ values. CLINICAL RELEVANCE: Replace the conventional drilling technique for an alternative, underpreparation or expanders, in low-quality bone in order to achieve greater primary stability.

Influence of Multiple Sterilization on Performance of Titanium Pegs When Measuring Implant Stability With Resonance Frequency Analyses.

This in vitro study was conducted to investigate the repeatability of the implant stability quotients (ISQ) measured with multipegs after numerous sterilizations and to detect the exact time when the readings start to deviate. Multipegs were sterilized with 3 different methods (autoclaved, autoclaved + ultrasonic cleaner, chemical disinfection + autoclaved) and grouped according to the method applied. All specimens were put into the autoclave with sealed packages every time they were sterilized. Each specimen was sterilized 50 times according to the technique described in its group after an ISQ measurement was performed. Results of the 2-way analysis of variance showed that neither the sterilization method nor the cycles, nor their interaction, were statistically significant. A multipeg may be reused multiple times after sterilization procedures and may be more cost-effective than a disposable smartpeg for checking implant stability after confirming these results in further investigations.

Insertion Torque and Resonance Frequency Analysis in Tapered and Parallel Dental Implants.

Primary implant stability (PIS) is known to vary with recipient bone mass and density, dental implant design and surgical technique. The objective of this preliminary study was to compare rotational and lateral PIS of same-coronal-diameter conical and parallel implants, using insertion torque recorded with a dental implant motor set and implant stability quotient obtained from resonance frequency analysis (performed with both Osstell and Penguin systems) as measures of rotational and lateral stability, respectively. Additionally, the relationship between PIS and alveolar ridge width (ARW) was explored in both implant types. Sixty dental implants (30 tapered and 30 parallel) were randomly placed with a split-mouth design in 17 patients. Bone density and ARW were estimated from cone beam computed tomography images taken with radiological-surgical templates. Density and width values were similar in the 2 groups (P > .05). Implant coronal diameters were 3.75 mm in all cases, while consistent with the manufacturer's recommendations, final drill bit diameters used were 3.25 and 3.4 mm for parallel and tapered implants, respectively. Insertion torque was higher (P < .05) with parallel implants, but between-group differences in implant stability quotient were not significant (P > .05). In tapered implants, insertion torque was inversely correlated with ARW (P < .001). Notably, significant differences were observed between resonance frequency analysis values from Osstell and Penguin systems (P < .001). In conclusion, future studies should explore how PIS may be influenced by final drill bit size regardless of implant design and potential limits on the effectiveness of tapered implants to achieve good stability in thick low-density bone.

Intra- and inter-operator concordance of the resonance frequency analysis. A cross-sectional and prospective clinical study.

OBJECTIVE: Resonance frequency analysis (RFA) provides an evaluation of implant stability over time. This analysis is a non-invasive, precise, and objective method. Several studies compare the RFA system with other devices. However, few investigations analyze repeatability and reproducibility between different operators. The aim of this study was to evaluate the intra- and inter-operator concordance of the Osstell® ISQ. MATERIAL AND METHODS: RFA measurements were performed with Osstell® ISQ in a total of 37 implants placed in 21 patients. At the time of implant placement, 6 measurements per implant were taken by three different experienced operators. Three measurements were carried out consecutively and three by removing and placing the SmartPeg-Osstell® to assess intra-operator and inter-operator agreement. RESULTS: Intra-operator concordance according to the intraclass correlation coefficient (ICC) showed high concordance. The ICC values were higher than 0.9 (p < 0.0001) for consecutive measures and alternative measures, being almost perfect of Landis & Koch classification. For inter-operator concordance The ICC was 0.709 (p < 0.0001) and 0.670 (p < 0.0001) for consecutive and alternative measures, respectively, both estimates being in the substantial category. In torque and ISQ values, no statistically significant differences were observed when operators and measurements were compared. CONCLUSIONS: Osstell® ISQ system was stable both in intra-operator and inter-operator measurements. This device has excellent repeatability and reproducibility, demonstrating reliability to measure the stability of dental implants. CLINICAL RELEVANCE: Resonance frequency analysis (RFA) is a non-invasive, objective, and reliable diagnostic method to determine the ideal moment to load the implant, as well as to predict possible failures.

Peri-implant bone microstructural analysis and comparison of resonance frequency analysis before prosthetic placement: a retrospective study.

OBJECTIVES: Fractal analysis is a mathematical method used for the calculation of bone trabeculation and lacunarity. This study aims to evaluate the relationship between resonance frequency analysis (RFA) and fractal dimension (FD) of peri-implant bone to determine the preload stability of implants. MATERIALS AND METHODS: In this study, the results of the fractal analysis calculated from the resonance frequency analysis results taken in the 3rd month of the patients who underwent 2-stage implant by the same doctor and the radiographs taken in the same session were evaluated. A hundred implants in 20 patients were applied in this study. The implant stability quotient (ISQ) values of the implants and fractal dimension values of the peri-implant bone were calculated. RESULTS: The findings showed that the ISQ1 (p = 0.008), ISQ2 (p = 0.038), ROI2 (p = 0.013), and ROI3 (p < 0.001) values were statistically significantly higher in men than women. The ISQ1 (p = 0.003), ISQ2 (p = 0.013), ROI1 (p = 0.011), and ROI3 (p < 0.001) of the mandible were statistically higher than the maxilla. The fractal dimension cut-off value to assess prosthetic loading was found 1.198. CONCLUSION: Fractal analysis is a non-invasive method that can be used in conjunction with clinical examination in the prosthetic loading decision of implants. It is a valuable parameter that can be used without the need for an extra device when it is necessary to reduce the clinical study time. CLINICAL RELEVANCE: Calculating the fractal dimension of the peri-implant bone is a practical, economical, and applicable method for clinicians. FD calculated from panoramic radiographs used for diagnosis in routine treatments in clinics where access to the necessary devices for ISQ measurement is not available will contribute to clinical practice.

Comparison of the Stability of Sandblasted, Large-Grit, and Acid-Etched Treated Mini-Screws With Two Different Surface Roughness Values: A Histomorphometric Study.

PURPOSE: To evaluate the effects of 2 different surface roughness values produced by sandblasted, large-grit, and acid-etched treatments at different loading conditions on the stability of mini-screws. MATERIAL AND METHODS: A total of 56 mini-screws (Group 1; 28 with Ra value of 1 µm, Group 2; 28 with Ra value of 1.5 µm) were inserted into the tibia of fourteen New Zealand rabbits. Surface analysis was performed before the placement of the miniscrews using multi-technique characterization. The mini-screws were loaded with 500 grf after different healing times: unloaded, immediate, 4 and 8 weeks. Resonance frequency analyses were performed immediately after mini-screw placement and at the end of loading. Biomechanical and histomorphometric analyses were also performed at the end of the loading period. RESULTS: All mini-screws preserved their stability at the end of the loading period. However, the resonance frequency analyses showed higher implant stability quotient scores for 8-week group, unlike the immediate loading and unloaded groups (P < 0.05). According to the infinite focus microscopy results, prolongation of healing time resulted in a greater bone area on the loaded mini-screws in Group 2 (P < 0.05). Similarly, the histomorphometric analysis revealed higher bone-to-implant contact values in the 8-week group. There was no significant difference in the stability between the miniscrews with the Ra values of 1 and 1.5 µm. CONCLUSIONS: Sandblasted, large-grit, and acid-etched treated mini-screws showed significantly higher stability with healing time under heavy forces. Sandblasted, large-grit, and acid-etched treated mini-screws can be removed without fracture of the screw or the bone surfaces.

Comparison of Reliability of 3 Resonance Frequency Analysis Devices: An In Vitro Study.

The purpose of the present study was to investigate the intraobserver and interobserver reliability of 3 resonance frequency analysis (RFA) devices and to compare the implant stability quotient (ISQ) values according to implant macro design and diameter in 2 different bone densities. A total of 64 implants (Neoss ProActive; Neoss; Harrogate, UK) of varying diameters (3.5 and 4.0 mm) and implant macro design (tapered and straight) were placed in 2 artificial bone blocks (the density of type 2 and 3). The implant primary stability was measured using Osstell IDx (Osstell; Göteborg, Sweden), Osstell Beacon and Penguin RFA (Integration Diagnostics; Göteborg, Sweden). The ISQ value of each implant was measured by 2 observers and recorded 5 times in 2 directions. The intraobserver and interobserver reliability of RFA devices were evaluated. In addition to that, mean ISQ values were calculated for each RFA device to evaluate the effect of implant diameter, implant macro design, and bone density on ISQ values. ISQ values were significantly higher for implants placed within the type 2 bone than for the type 3 bone. The 4.0-mm diameter implants presented higher ISQ values than 3.5-mm diameter implants. The intraclass correlation coefficient (ICC) values for intraobserver reliability were above 0.85 for each observer and the ICC values for interobserver reliability were 0.94, 0.93, and 0.98 for Osstell IDx, Osstell Beacon, and Penguin RFA, respectively. Although there was excellent interobserver reliability with 3 RFA devices, the intraobserver reliability of Osstell Beacon and Penguin RFA were slightly better than Osstell IDx. Bone density and implant diameter were parameters affecting the primary stability of implants.

Primary Stability of Trabecular Metal Implant in Comparison to Fully Threaded Implants: In Vitro Study Simulating Immediate Implant Placement.

The aim of this study was to evaluate primary stability of 3.7-mm diameter porous tantalum Trabecular Metal (TM) implant, and compare it to fully threaded implants, in the in vitro model of immediate implant placement in the anterior maxilla. A total of 60 implants were placed into bovine ribs using surgical guides. Implants were divided in 3 groups of 20 according to the design: TM, Tapered Screw-Vent (TSV), and NobelReplace. To simulate immediate placement in anterior maxilla, implants were placed under a sharp angle toward the ribs, not fully submerged. Placement angle of 20.7° was calculated after analysis of 148 virtually planned implants on cone beam computerized tomography scans of 40 patients. No statistically significant difference in implant stability quotient (ISQ) was found between TM (65.8 ± 2.6), TSV (64.7 ± 2.7), and NobelReplace (64.6 ± 2.7). TSV implants achieved higher insertion torque (37.0 ± 4.8 Ncm) than TM (32.9 ± 5.2 Ncm) and NobelReplace (23.2 ± 3.3 Ncm). TSV had the shortest insertion time of 13.5 ± 1.0 seconds, compared to 15.2 ± 1.2 seconds for TM, and 19.7 ± 1.7 seconds for NobelReplace. Pearson correlation analysis showed significantly correlated insertion torque and ISQ values for TM group (P = .011, r = .56), a nonsignificant correlation was found for TSV and NobelReplace. The results of the present study indicate that TM implant can achieve good primary implant stability in insertion torque and resonance frequency analysis.

Analysis of implant stability changes in immediate loading using a laser displacement sensor in vivo and comparison of its sensitivity with that of resonance frequency analysis.

OBJECTIVE: The aim of this study was to analyze the stability changes in immediately loaded implants by using an in vivo quantitative measurement of micromotion under functional dynamic loading and to verify the sensitivity of Resonance Frequency Analysis (RFA) as compared to that of actual micromotion. MATERIALS AND METHODS: The micromotions of immediately loaded implants placed in the tibia of 11 rabbits were monitored using a laser displacement sensor. Functional dynamic loading forces were applied 5 days a week for 6 weeks. The implant stability quotient (ISQ) was monitored using RFA. RESULTS: The micromotion of the almost-loaded implants increased to peak values the day after loading was started and subsequently reached a plateau gradually. The ISQ changes in the loaded implants closely correlated with the alterations of the actual micromotion (r = -0.98, p < .01). Although the ISQ value itself correlated with the measured micromotion at the time of initial fixation (r = 0.73, p < .05), it did not correlate with the micromotion of the implant that acquired integration. No close correlation was observed between the ISQ and the histomorphometrical data. CONCLUSION: The immediately loaded implants showed the lowest stability immediately after the start of loading, which gradually increased thereafter. RFA is considered a useful method for examining stability changes and initial stability; however, it cannot determine the absolute magnitude of the stability after integration.

Resonance frequency analysis of implants placed in condensed bone.

OBJECTIVES: Resonance frequency analysis (RFA) is used to monitor implant stability. Its output, the Implant Stability Quotient (ISQ), supposedly correlates with insertion torque, a common measurement of primary stability. However, the reliability of RFA in condensed bone remains unclear. MATERIAL AND METHODS: In this human cadaver study in edentulous jaws and fresh extraction sockets, implants were inserted using a split-mouth approach into condensed or untreated bone. Mean ISQ, peak insertion torque, and pre- and postoperative bone volume fractions (BV/TV) were assessed. RESULTS: In edentulous jaws, insertion torque and ISQ correlated both in untreated (r = 0.63, p = 0.02) and in condensed (r = 0.82, p  < 0.01) bone. In extraction sockets, insertion torque and ISQ only correlated in untreated (r = 0.78, p < 0.01), but not in condensed bone (r = 0.15, p = 0.58). In all edentulous jaws, preoperative BV/TV correlated with insertion torque (r = 0.90, p < 0.0001), ISQ (r = 0.64, p < 0.001), and changes in BV/TV (r = -0.71, p < 0.01). In all extraction sockets, preoperative BV/TV did not correlate with either insertion torque (r = 0.33, p = 0.15), ISQ (r = 0.38, p = 0.09), or changes in BV/TV (r = -0.41, p = 0.09). Joint analysis identified preoperative BV/TV as a predictor of postoperative BV/TV (p < 0.001), insertion torque (p < 0.001), and ISQ (p < 0.001). CONCLUSIONS: RFA is feasible for monitoring stability after late implant placement into condensed bone, but not after immediate placement into condensed fresh extraction sites.

Machine Learning-Based Diagnosis in Laser Resonance Frequency Analysis for Implant Stability of Orthopedic Pedicle Screws.

Evaluation of the initial stability of implants is essential to reduce the number of implant failures of pedicle screws after orthopedic surgeries. Laser resonance frequency analysis (L-RFA) has been recently proposed as a viable diagnostic scheme in this regard. In a previous study, L-RFA was used to demonstrate the diagnosis of implant stability of monoaxial screws with a fixed head. However, polyaxial screws with movable heads are also frequently used in practice. In this paper, we clarify the characteristics of the laser-induced vibrational spectra of polyaxial screws which are required for making L-RFA diagnoses of implant stability. In addition, a novel analysis scheme of a vibrational spectrum using L-RFA based on machine learning is demonstrated and proposed. The proposed machine learning-based diagnosis method demonstrates a highly accurate prediction of implant stability (peak torque) for polyaxial pedicle screws. This achievement will contribute an important analytical method for implant stability diagnosis using L-RFA for implants with moving parts and shapes used in various clinical situations.

Evaluation of the primary stability in dental implants placed in low density bone with a new drilling technique, Osseodensification: an in vitro study.

BACKGROUND: Primary stability is an important key determinant of implant osseointegration. We investigated approaches to improve primary implant stability using a new drilling technique termed osseodensification (OD), which was compared with the conventional under-drilling (UD) method utilized for low-density bones. MATERIAL AND METHODS: We placed 55 conical internal connection implants in each group, in 30 low-density sections of pig tibia. The implants were placed using twist drill bits in both groups; groups Under Drilling (UD) and Osseodensification (OD) included bone sections subjected to conventional UD and OD drilling, respectively. Before placing the implants, we randomized the bone sections that were to receive these implants to avoid sample bias. We evaluated various primary stability parameters, such as implant insertion torque and resonance frequency analysis (RFA) measurements. RESULTS: The results showed that compared with implants placed using the UD technique, those placed using the OD technique were associated with significantly higher primary stability. The mean insertion torque of the implants was 8.87±6.17 Ncm in group 1 (UD) and 21.72±17.14 Ncm in group 2 (OD). The mean RFA was 65.16±7.45 ISQ in group 1 (UD) and 69.75±6.79 ISQ in group 2 (OD). CONCLUSIONS: The implant insertion torque and RFA values were significantly higher in OD group than in UD. Therefore, compared with UD, OD improves primary stability in low-density bones (based on torque and RFA measurements).

Effect of undersized drilling on the stability of immediate tapered implants in the anterior maxillary sector. A randomized clinical trial.

BACKGROUND: To evaluate the effect of undersized drilling on the primary and secondary stability of immediate implants placed in the anterior maxilla. MATERIAL AND METHODS: A comparative randomized clinical trial was carried out in 30 healthy adults. Thirty tapered implants, 16 involving conventional drilling and 14 undersized drilling, were placed immediately after anterior maxillary tooth removal. Insertion torque and implant stability assessed by resonance frequency analysis (RFA) were evaluated at three different timepoints: at implant placement and 6 and 12 weeks post-implantation. The results were compared using parametric statistical tests. RESULTS: All implants showed adequate stability during follow-up. At implant placement, the undersized drilling group exhibited greater insertion torque values than the conventional drilling group, but stability assessed by RFA showed greater mean values in the conventional group. After 6 and 12 weeks of follow-up, both groups showed improved stability, though the RFA values remained comparatively higher in the conventional group. The differences were not statistically significant. CONCLUSIONS: Based on the results obtained, undersized drilling does not appear to afford significantly improved stability of immediate implants placed in the anterior zone of the maxilla during the osseointegration period.

Comparative Evaluation of Implant Stability, Insertion Torque, and Implant Macrogeometry in Different Bone Densities Using Resonance Frequency Analysis.

AIM AND OBJECTIVE: Evaluation and comparison of insertion torque (IT) and the implant stability of two different implant macrogeometry in different bone densities using resonance frequency analysis. MATERIALS AND METHODS: A total of 48 implants (with two implant types having regular and novel macrogeometry) were classified into 4 groups with 12 samples in each group. Group A regular implant without surface treatment, group B regular implant with surface treating, group C novel implant deprived of surface treating, and group D was new dental implant with surface treatment were used. Implant stability quotient (ISQ), implant IT, removal torque (RT) percentage, and torque reduction percentage were calculated. RESULTS: The mean ± SD ISQ value of bone 1 in group A was 56.7 ± 3.2, in group B was 58.6 ± 2.4, in group C was 57.1 ± 3.5, and in group D was 59.3 ± 2.9. In bone 2, the value was 57.8 ± 1.4, 59.5 ± 1.5, 58.2 ± 2.6, and 59.5 ± 2.4 among A, B, C, and D groups correspondingly. In bone 3, it was 59.4 ± 2.4, 60.3 ± 2.3, 60.4 ± 2.8, and 62.7 ± 2.5 among A, B, C, and D groups correspondingly. In bone 4, it was 67.2 ± 3.4, 69.5 ± 2.7, 68.7 ± 2.4, and 69.4 ± 2.3 among A, B, C, and D groups correspondingly. There was a substantial difference in IT and nonsignificant difference in RT in different groups. CONCLUSION: There was a low IT value with new implant macrogeometry as compared to regular implant macrogeometry. There was absence of association between IT and implant stability. CLINICAL SIGNIFICANCE: Calculation of torque insertion score helps in implant placement. Higher bone density scores produce a higher option of decreasing the initial torque. Low IT of new implant types is useful to reduce failure.