Evaluating stiffness of gastric wall using laser resonance frequency analysis for gastric cancer.

Tumor stiffness is drawing attention as a novel axis that is orthogonal to existing parameters such as pathological examination. We developed a new diagnostic method that focuses on differences in stiffness between tumor and normal tissue. This study comprised a clinical application of laser resonance frequency analysis (L-RFA) for diagnosing gastric cancer. L-RFA allows for precise and contactless evaluation of tissue stiffness. We used a laser to create vibrations on a sample's surface that were then measured using a vibrometer. The data were averaged and analyzed to enhance accuracy. In the agarose phantom experiments, a clear linear correlation was observed between the Young's modulus of the phantoms (0.34-0.71 MPa) and the summation of normalized vibration peaks (Score) in the 1950-4050 Hz range (R2 = 0.93145). Higher Young's moduli also resulted in lower vibration peaks at the excitation frequency, signal-to-noise (S/N) ratios, and harmonic peaks. We also conducted L-RFA measurements on gastric cancer specimens from two patients who underwent robot-assisted distal gastrectomy. Our results revealed significant waveform differences between tumor and normal regions, similar to the findings in agarose phantoms, with tumor regions exhibiting lower vibration peaks at the excitation frequency, S/N ratios, and harmonic peaks. Statistical analysis confirmed significant differences in the score between normal and tumor regions (p = 0.00354). L-RFA was able to assess tumor stiffness and holds great promise as a noninvasive diagnostic tool for gastric cancer.

Detection of Total Hip Replacement Loosening Based on Structure-Borne Sound: Influence of the Position of the Sensor on the Hip Stem.

Accurate detection of implant loosening is crucial for early intervention in total hip replacements, but current imaging methods lack sensitivity and specificity. Vibration methods, already successful in dentistry, represent a promising approach. In order to detect loosening of the total hip replacement, excitation and measurement should be performed intracorporeally to minimize the influence of soft tissue on damping of the signals. However, only implants with a single sensor intracorporeally integrated into the implant for detecting vibrations have been presented in the literature. Considering different mode shapes, the sensor's position on the implant is assumed to influence the signals. In the work at hand, the influence of the position of the sensor on the recording of the vibrations on the implant was investigated. For this purpose, a simplified test setup was created with a titanium rod implanted in a cylinder of artificial cancellous bone. Mechanical stimulation via an exciter attached to the rod was recorded by three accelerometers at varying positions along the titanium rod. Three states of peri-implant loosening within the bone stock were simulated by extracting the bone material around the titanium rod, and different markers were analyzed to distinguish between these states of loosening. In addition, a modal analysis was performed using the finite element method to analyze the mode shapes. Distinct differences in the signals recorded by the acceleration sensors within defects highlight the influence of sensor position on mode detection and natural frequencies. Thus, using multiple sensors could be advantageous in accurately detecting all modes and determining the implant loosening state more precisely.

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.

Associations between cortical bone-to-implant contact and microstructure derived from CBCT and implant primary stability.

OBJECTIVES: To evaluate the associations between the cortical bone-to-implant contact (CBIC), bone microstructure derived from cone-beam computed tomography (CBCT), and the primary stability of the implant. MATERIALS AND METHODS: Twenty-two patients with 65 implants were enrolled in this study. The peak insertion torque values (ITVs) were measured during implant insertion, and the implant stability quotient (ISQ) values were measured immediately after implant placement and 3 months after surgery. The profiles of the peri-implant bone structure were outlined using the volumetric reconstruction of the CBCTs and superimposition of the virtual models, and the features of CBIC and bone microstructure parameters were measured. The linear mixed effects model and generalized estimating equation were used to explore the predictors for implant primary stability. RESULTS: The average ITV, baseline, and secondary ISQ values were 31.44 ± 6.54 N·cm, 73.34 ± 7.39, and 80.32 ± 4.58, respectively. Statistically significant correlations were found between ITV and surface area of CBIC (r = .340, p = .006), bone volume fraction (r = .294, p = .017), and bone surface fraction (r = -.278, p = .039). Implants with buccolingual CBIC had a higher ITV than implants without CBIC (p = .016). None of the parameters were associated with baseline and secondary ISQ values in generalized estimating equation analysis (all p > .05). CONCLUSIONS: Within the limitations of the study, preoperative CBCT measurements might enable the prediction of ITV and therefore of implant primary stability values.

Survival and stability of strategic mini-implants with immediate or delayed loading under removable partial dentures: a 3-year randomized controlled clinical trial.

OBJECTIVES: Stability values of mini-implants (MIs) are ambiguous. Survival data for MIs as supplementary abutments in reduced dentitions are not available. The aim of this explorative research was to estimate the 3-year stability and survival of strategic MIs after immediate and delayed loading by existing removable partial dentures (RPDs). MATERIAL AND METHODS: In a university and three dental practices, patients with unfavorable tooth distributions received supplementary MIs with diameters of 1.8, 2.1, and 2.4 mm. The participants were randomly allocated to group A (if the insertion torque ≥ 35 Ncm: immediate loading by housings; otherwise, immediate loading by RPD soft relining was performed) or delayed loading group B. Periotest values (PTVs) and resonance frequency analysis (RFA) values were longitudinally compared using mixed models. RESULTS: A total of 112 maxillary and 120 mandibular MIs were placed under 79 RPDs (31 maxillae). The 1st and 3rd quartile of the PTVs ranged between 1.7 and 7.8, and the RFA values ranged between 30 and 46 with nonrelevant group differences. The 3-year survival rates were 92% in group A versus 95% in group B and 99% in the mandible (one failure) versus 87% in the maxilla (eleven failures among four participants). CONCLUSIONS: Within the limitations of explorative analyses, there were no relevant differences between immediate and delayed loading regarding survival or stability of strategic MIs. CLINICAL RELEVANCE: The stability values for MIs are lower than for conventional implants. The MI failure rate in the maxilla is higher than in the mandible with cluster failure participants. CLINICAL TRIAL REGISTRATION: German Clinical Trials Register (Deutsches Register Klinischer Studien, DRKS-ID: DRKS00007589, www.germanctr.de ), January 15, 2015.

Comparison of Implant Stability Between Conventional Drilling and Piezosurgical Implant Bed Preparation Techniques.

This prospective study compared the stability of implants placed using piezoelectric surgery (piezo group) and those placed using conventional rotary drills (bur group) during the first 90 days postoperatively. Teeth in the posterior maxillary regions of 21 patients were randomly assigned to 2 groups. The implant stability quotient (ISQ) was measured at days 0, 7, 14, 21, 28, 42, 56, and 90 postoperatively. Twenty-eight of 29 implants were successfully integrated at day 90 (1 implant in the test group was lost). Although both groups showed a significant overall increase in implant stability with time (P < .0001) and a high final mean ISQ value, no statistically significant difference in stability was seen between the groups. The bur group showed greater variance in ISQ values than the piezo group did (P < .001) at all time points. Long-term studies with larger samples are needed to investigate the bone response to the use of piezoelectric surgery for implant preparation.

Randomized Clinical Trial Comparing Insertion Torque and Implant Stability of Two Different Implant Macrogeometries in the Initial Periods of Osseointegration.

Objectives: The present study compared two implants with different macrogeometries placed in healed alveolar sites, evaluating the insertion torque (ITV) and implant stability quotient (ISQ) values at three different periods. Methods: Seventy patients with a total of 100 dental implants were allocated into two groups (n = 50 per group): DuoCone implants (DC group) that included 28 implants in the maxilla and 22 in the mandible, and Maestro implants (MAE group) that included 26 in the maxilla and 24 in the mandible. The ITV was measured during the implant placement, and the ISQ values were measured immediately at implant placement (baseline) and after 30 and 45 days. Results: The mean and standard deviations of the ITV were statistically significant (p < 0.0001), 56.4 ± 6.41 Ncm for the DC group and 29.3 ± 9.65 Ncm for the MAE group. In the DC group, the ISQs ranged between 61.1 ± 3.78 and 69.8 ± 3.86, while the MAE group presented similar values compared with the other group, ranging between 61.9 ± 3.92 and 72.1 ± 2.37. Conclusions: The value of implant insertion torque did not influence the ISQ values measured immediately after implant placement. However, the ITV influenced the ISQ values measured in the two initial periods of osseointegration, with implants installed with lower torques presenting higher ISQ values.

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.

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.

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.

Does shelf preparation have efficacy on immediate loading of 4 implants supporting screw-retained full-arch dental prosthesis?

Background: Bone reduction and shelf preparation is a common procedure to establish a new alveolar plane before implant surgery, which might effect the primary stability. Aim: Primary stability was questioned in terms of bone reduction and shelf preparation. The suitability of immediate loading was compared between the implants placed on crests, which underwent alveoloplasty, and the implants placed on a naturally healed alveolar bone. Patients and Methods: We designed and implemented a retrospective cohort study. Twenty patients (mean age 49.2 years) were treated with 160 dental implants. The primary predictor variable was extraction and bone reduction. The secondary predictor variables were bone density and the implant surface. The outcome variables were resonance frequency analysis (RFA) and insertion torque (IT) values. Results: There was no statistically significant difference between groups regarding RFA and IT (P > 0,05). Interactions of surface area with the RFA and IT in both groups were not statistically significant; however, bone density presented a statistically significant effect on outcome variables for both groups. Conclusion: IT and RFA are not influenced by bone reduction, shelf preparation, or the implant surface. Primary stability is mostly affected by bone density in the immediate load of 4 implants to support a full-arch prosthesis.

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.

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.

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.

Factors Affecting Implant Stability Quotients at Immediately and Conventionally Loaded Implants in the Posterior Maxilla: A Split-Mouth Randomized Controlled Trial.

PURPOSE: To assess primary and secondary stability of variable-thread tapered implants in the posterior maxilla and analyze the impact of various factors on implant stability quotients (ISQs). MATERIALS AND METHODS: Twenty-six subjects received 3-4 adjacent implants in the maxillary premolar-molar sextants to replace bilateral tooth loss. The implants on one side were immediately loaded with a provisional fixed prosthesis regardless of their primary stability. The contralateral control implants were conventionally loaded. Bone quality was subjectively recorded and primary stability was assessed by means of insertion torque values (ITVs) and ISQs in 4 directions. Secondary stability was measured by ISQ at definitive prosthesis delivery (3-3.5 months postoperatively), and 12 months after definitive loading. The impact of measurement direction, loading protocol, time, site-related (bone quality, implant position, crestal buccal bone thickness, apical cortical anchorage), and implant-related (implant dimensions, abutment height) variables on ISQs was assessed. RESULTS: For logistic reasons, ISQs were obtained for only 18 patients with 60 test and 60 control implants. Most of the implants (82%) at baseline had their lowest ISQ on the buccal aspect. There were no significant differences between ISQs measured in the buccal and palatal directions, or between ISQs in the mesial and distal directions. The mean of buccal and palatal ISQs was significantly lower than the mean of the 2 interproximal measurements at all evaluation periods. ISQs were not significantly different between the 2 loading groups at any time point. All implants showed a time-dependent increase in ISQs. Baseline ISQ correlated weakly with bone quality and ITV. None of the variables had a significant impact on baseline ISQs, except for implants in second molar sites which showed poorer primary stability than first premolars. CONCLUSION: Measurement direction and time are the most significant parameters affecting ISQs of variable-thread tapered implants in the posterior maxilla.

Influence of Cortical Layer and Surgical Techniques on the Primary Implant Stability in Low-density Bone: An In Vitro Study.

AIM: This study aimed at evaluating the influence of cortical layer and surgical techniques on the primary stability of implants in low-density bone. MATERIALS AND METHODS: Two solid rigid polyurethane blocks with a density equivalent to 0.32 g/cm3 simulating cancellous bone were used. A short fiber-filled epoxy resin sheet of 2 mm was layered to one block to simulate cortico cancellous bone. A total of 40 implants were used in this study (n = 40). Twenty implants each (n = 20) were inserted in cancellous (Group 1) and cortico-cancellous bone (Group 2), of which 10 implants each (n = 10) were placed using undersized preparation technique with surgical drills-A and osteotomes-B, in both the groups. Insertion torque (IT) and implant stability quotient (ISQ) for each implant placed were assessed to determine the primary stability of each implant using a digital torque meter and resonance frequency analyzer, respectively. The values were statistically analyzed using an independent t-test (p < 0.05). Pearson's correlation analysis was performed to correlate between IT and ISQ. RESULTS: Technique B resulted in significantly higher IT and ISQ values in Group 1 (27.69 ± 1.2 N cm; 52.5 ± 1.05 ISQ) and Group 2 (38.8 ± 0.87 N cm; 70.1 ± 1.04 ISQ) compared to those with technique A (22.40 ± 1.62 N cm; 41.75 ± 1.20 ISQ and 33.24 ± 0.67 N cm; 63.72 ± 1.33 ISQ), respectively. Group 2 exhibited significantly higher IT and ISQ values as compared to Group 1 irrespective of the surgical technique employed (p < 0.05). CONCLUSION: The presence of the cortical layer significantly influenced the primary stability and preparing low-density bone with an undersized preparation technique using osteotomes that significantly increased the IT and ISQ. CLINICAL SIGNIFICANCE: Undersizing the preparation site considerably will help achieve a significant increase in primary stability in the poor quality bone as in the posterior maxilla, thereby contributing to the success of the implant.

Use of resonance frequency analysis to evaluate the effects of surface properties on the stability of different implants.

OBJECTIVES: We performed a randomized clinical study evaluating the stability of implants with different surfaces (alkali-modified or sandblasted) via resonance frequency analysis (RFA). MATERIALS AND METHODS: Fourteen patients who were bilaterally edentulous in terms of their mandibular molars were enrolled. Implants with alkali-modified (bioactive) and sandblasted surfaces were randomly placed in either hemi-arch; the 50 implants used were identical in terms of diameter and length. RFA was used to measure the implant stability quotient (ISQ) immediately after placement (to assess primary stability) and 2, 6, and 12 weeks later. RESULTS: The average RFA value for alkali-modified implants was significantly higher than that for sandblasted implants immediately after implantation, but the ISQs fell rapidly and were similar in the two groups at 2 and 6 weeks (p > .05); ISQ values were the same in the two groups at 3 months (p > .05). CONCLUSIONS: Implants with alkali-modified surfaces were more stable than implants with sandblasted surfaces at all times after placement. The ISQs of bioactive implants exhibiting high-level primary stability fell to greater extents than did those of implants with sandblasted surfaces at 2 and 6 weeks postoperatively; both types of implant yielded similar clinical results at 12 weeks postoperatively.

Relationship between Implant Length and Implant Stability of Single-Implant Restorations: A 12-Month Follow-Up Clinical Study.

Background and Objectives: Implant stability in vivo is contingent on multiple factors, such as bone structure, instrument positioning and implant surface modifications, implant diameter, and implant length. Resonance-frequency analysis is considered a non-invasive, reliable, predictable, and objective method by which to evaluate implant stability, due to its correlation with bone-to-implant contact. The purpose of this study was to evaluate the effect of implant length on the primary and secondary stability of single-implant crown rehabilitations, as measured by resonance-frequency analysis at different times. Materials and Methods: Implants of 10 and 11.5 mm were placed, and the resonance frequency was measured at the time of surgery (T0), as well as at 3 (T1), 6 (T2), and 12 (T3) months post-surgery. Results: A total of 559 implants were placed in 195 patients. Significant differences were observed when comparing the implant stability quotient (ISQ) values at T1, with values for 10-mm implants being greater than those for 11.5-mm implants (p = 0.035). These differences were also observed when comparing ISQ values for buccal and lingual areas. At T0, T2, and T3, no significant differences in ISQ values were observed. The use of 10-mm implants in the anterior maxilla yielded significantly greater values at T0 (p = 0.018) and T1 (p = 0.031) when compared with 11.5-mm implants. Significant differences in measurements were observed only for buccal areas (p = 0.005; p = 0.018). When comparing the sample lengths and sex, women with 11.5-mm implants showed significantly lower results than those with 10-mm implants (p < 0.001). Conclusions: There is a direct relationship between implants of a smaller length and greater ISQ values, with this relationship being most evident in the maxilla and in women.

To compare the stability and crestal bone loss of implants placed using osseodensification and traditional drilling protocol: A clinicoradiographical study.

AIM: The present study was done to evaluate and compare the stability of the implant and the loss of crestal bone in the implants placed using OD drilling and traditional drilling technique. SETTING AND DESIGN: In vivo-comparative study. MATERIALS AND METHODS: A total of 20 implants were placed in the anterior maxilla, and the patients were divided into two groups. In Group I, the implants were placed using traditional drilling technique, and in Group II, implant placement was done using OD drilling technique. Primary stability was measured in both the groups at baseline (immediate postoperative), and at an interval of 6 months, while crestal bone levels were measured at baseline, 6, and 8 months. STATISTICAL ANALYSIS USED: The data obtained were subjected to unpaired t-test to make intergroup comparisons, while one-way ANOVA F-test was used to make intragroup comparisons. RESULTS: The primary stability of implant placed using OD drills was found to be slightly higher than implant placed with traditional drilling; however, there was no statistical significance (P > 0.05). When the data obtained for crestal bone levels were statistically analyzed, no significant difference between the two groups was obtained (P > 0.05). CONCLUSION: Within the limitations of this study following conclusions were drawn: there was no statistically significant difference in implant stability between the traditional drilling and OD drilling (P < 0.05). On comparison of crestal bone levels between OD and traditional drilling, no statistically significant difference was found between the two groups (P < 0.05).