Investigating the impact of breast positioning control on physical treatment parameters in multi-catheter breast brachytherapy.

PURPOSE: To assess the effects of a workflow for reproducible patient and breast positioning on implant stability during high-dose-rate multi-catheter breast brachytherapy. METHODS: Thirty patients were treated with our new positioning control workflow. Implant stability was evaluated based on a comparison of planning-CTs to control-CTs acquired halfway through the treatment. To assess geometric stability, button-button distance variations as well as Euclidean dwell position deviations were evaluated. The latter were also quantified within various separated regions within the breast to investigate the location-dependency of implant alterations. Furthermore, dosimetric variations to target volume and organs at risk (ribs, skin) as well as isodose volume changes were analyzed. Results were compared to a previously treated cohort of 100 patients. RESULTS: With the introduced workflow, the patient fraction affected by button-button distance variations > 5 mm and by dwell position deviations > 7 mm were reduced from 37% to 10% and from 30% to 6.6%, respectively. Implant stability improved the most in the lateral to medial breast regions. Only small stability enhancements were observed regarding target volume dosimetry, but the stability of organ at risk exposure became substantially higher. D0.2ccm skin dose variations > 12.4% and D0.1ccm rib dose variations > 6.7% were reduced from 11% to 0% and from 16% to 3.3% of all patients, respectively. CONCLUSION: Breast positioning control improved geometric and dosimetric implant stability for individual patients, and thus enhanced physical plan validity in these cases.

Three-dimensional changes and influencing factors of tent space following osteotome sinus floor elevation without grafting: A 48-month retrospective radiographic study.

OBJECTIVES: To analyze the three-dimensional stability and morphologic changes of tent space after the osteotome sinus floor elevation (OSFE) procedures without bone grafts. MATERIALS AND METHODS: Forty-six implants placed using the OSFE technique with simultaneous implant placement without bone grafts were included in this retrospective study. Cone-beam computed tomography (CBCT) scans of the augmented sinuses were obtained pre- and postoperatively up to 48 months of follow-up. The maxillary sinus cavity profiles were outlined using three-dimensional virtual reconstruction and superimposition of CBCT scans. The three-dimensional changes in the tent space were measured. A generalized estimating equation (GEE) was used to explore potential factors. RESULTS: The implant survival rate was 97.8%. The mean volume of remaining tent space immediately after surgery was 96.8 ± 70.5 mm3, shrinking to 31.0 ± 24.9 mm3 after 48 months, while the mean percentage of remaining tent space volume decreased to 29.1 ± 20.7%. The tent space volume and the percentage of residual tent space volume only decreased significantly within 12 months after surgery (p = .008, .013). GEE results indicated positive correlations between the percentage of remaining tent space volume and implant protrusion length (p = .000) and apical height (p = .000), with a negative correlation between the sinus floor area immediately after surgery (p = .002) and the healing time (p = .022). CONCLUSIONS: The volume of the tent space rapidly shrank after OSFE without bone grafts. Several factors might influence the tent space stability. Long-term clinical trials with larger sample sizes are necessary to further validate the results.

Nano-superhydrophilic and bioactive surface in poor bone environment. Part 1: transition from primary to secondary stability. A controlled clinical trial : Bioactive implant surfaces in poor density bone.

OBJECTIVES: Bioactive surfaces were designed to increase the interaction between the surface and the cells. This may speed up the biological stability and loading protocols. MATERIALS AND METHODS: 36 patients with D3-D4 bone density were recruited and allocated into two groups. 30 bioactive (test group) and 30 traditional (control group) surfaced implants were placed. Insertion torque value (Ncm), insertion torque curve integral (cumulative torque, Ncm), torque density (Ncm/sec), implant stability quotient (ISQ) measured at three timepoints (baseline (T0), 30 (T30) and 45 (T45) days after surgery), and marginal bone loss (MBL) at 6 months of loading were assessed. RESULTS: The mean ISQ and standard deviation at T0, T30, T45 were respectively 74.57 ± 7.85, 74.78 ± 7.31, 74.97 ± 6.34 in test group, and 77.12 ± 5.83, 73.33 ± 6.13, 73.44 ± 7.89 in control group, respectively. Data analysis showed significant differences between groups in ΔISQ at T0-T30 (p = 0.005) and T30-T45 (p = 0.012). Control group showed a significant decrease in ISQ at T30 (p = 0.01) and T45 (p = 0.03) compared to baseline, while no significant change was observed in test group. Due to the stability of the ISQ value ≥ 70, 26 test group and 23 control group implants were functionally loaded after 45 days. Conversely, due to the ISQ < 70 at T45, four test group implants and one control group implant were loaded after 90 days, and 6 control group implants were loaded after 180 days. Neither insertion torque nor ISQ at baseline were correlated with bone density (in Hounsfield units). There was no significant correlation between cumulative torque and ISQ at baseline. There was a significant positive slope in the correlation between torque density and ISQ at baseline, more accentuated in D3 than D4. This correlation remained significant for the test group in D3 bone at day 30 and 45 (p < 0.01 in both time frames), but not in D4 bone, and it was not significant in CG. CONCLUSIONS: The bioactive surface showed better behavior in terms of implant stability in D3-D4 bone quality in the early stages of bone healing. Clinical relevance This study demonstrated that the transition from primary to secondary stability is improved using bioactive surface, especially in cases of poor bone environment (D3/D4 bone).

Implant stability and clinical outcome between implant placement using internal sinus floor elevation with alloplastic bone material grafting and without grafting: A 1-year randomized clinical trial.

OBJECTIVE: To compare implant stability and clinical outcome in implant placement between osteotome sinus floor elevation (OSFE) with biphasic calcium phosphate (BCP) which consisted of 30% of hydroxyapatite (HA) and 70% of beta-tricalcium phosphate (ß -TCP) grafting material and OSFE without using bone grafting material. The research questions is whether the BCP provides any benefit in OSFE or not. MATERIALS AND METHODS: Thirty patients (30 implants) with a single edentulous area of upper premolar or molar were randomly separated into OSFE with BCP (n = 15) and OSFE without grafting (n = 15). The patients were reevaluated 3, 6, 9, and 12 months after implant loading. The clinical assessments (implant stability quotient (ISQ), implant survival-failure rate, and surgical complication) were analyzed. Together with radiographic assessments in 2D (endo-sinus bone gain (ESBG), mean marginal bone change (MMBC)) and 3D (endo-sinus bone gain in CBCT (ESBG-CT)) were evaluated, with a mean follow-up time of at least 12 months of functional loading and prosthetic complication. RESULTS: 20 remaining implants (OSFE with BCP, n = 10; OSFE without grafting, n = 10) were analyzed. Mean ISQ was 79.18 ± 3.43 in 1-year follow-up (ISQ; OSFE with BCP = 78.72 ± 3.46, OSFE without grafting = 79.65 ± 3.52). ISQ in both groups increased steadily without significant differences in each follow-up. (p = 0.56). In radiographic evaluation, at 6-, 9-, and 12-month, OSFE without grafting group showed statistically significant lower MMBC (p < 0.05). The 1-year clinical results showed that 2 implants failed in OSFE with BCP, and 1 implant failed in OSFE without grafting. CONCLUSIONS: Graft material "BCP" (HA30:TCP70) coupled with OSFE presents no extraordinary benefit in implant stability, clinical and radiographic outcome in 1-year follow-up. CLINICAL RELEVANCE: Clinically, OSFE with grafting materials provides no additional benefit. CLINICAL TRIAL REGISTRATION NUMBER: TCTR20210517008 (date of registration: May 17, 2021).

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.

Modular baseplate augmentation: a simple and effective method for addressing eccentric glenoid wear.

BACKGROUND: Augmented baseplates can be effective at addressing eccentric glenoid wear in reverse total shoulder arthroplasty. However, these implants often come in a limited number of predetermined shapes that require additional reaming to ensure adequate glenoid seating. This typically involves complex instrumentation and can have a negative impact on implant stability. Modular baseplate augmentation based on intraoperative measurements may allow for more precise defect filling while preserving glenoid bone. The purpose of this investigation was to assess the stability of a novel ringed baseplate with modular augmentation in comparison with nonaugmented standard and ringed baseplate designs. METHODS: In this biomechanical study, baseplate micromotion was tested for 3 constructs according to the American Society for Testing and Materials guidelines. The constructs included a nonaugmented curved baseplate, a nonaugmented ringed baseplate, and a ringed baseplate with an 8-mm locking modular augmentation peg. The nonaugmented constructs were mounted flush onto polyurethane foam blocks, whereas the augmented baseplate was mounted on a polyurethane block with a simulated defect. Baseplate displacement was measured before and after 100,000 cycles of cyclic loading. RESULTS: Before cyclic loading, the nonaugmented and augmented ringed baseplates both demonstrated significantly less micromotion than the nonaugmented curved baseplate design (81.1 µm vs. 97.2 µm vs. 152.7 µm; P = .009). After cyclic loading, both ringed constructs continued to have significantly less micromotion than the curved design (105.5 µm vs. 103.2 µm vs. 136.6 µm; P < .001). The micromotion for both ringed constructs remained below the minimum threshold required for bony ingrowth (150 µm) at all time points. CONCLUSIONS: In the setting of a simulated glenoid defect, locked modular augmentation of a ringed baseplate does not result in increased baseplate micromotion when compared with full contact nonaugmented baseplates. This design offers a simple method for tailored baseplate augmentation that can match specific variations in glenoid anatomy, limiting the need for excessive reaming and ultimately optimizing the environment for long-term implant stability.

Are Flexible Metaphyseal Femoral Cones Stable and Effective? A Biomechanical Study on Hinged Total Knee Arthroplasty.

BACKGROUND: Cones currently available in the market are rigid, and unless they are custom-specific designed, are unable to correctly adapt to the shape of the patient's bone. Therefore, flexible metaphyseal cones have been recently introduced to reduce potential bone trauma during implantation. Even if a preliminary clinical study on their use has shown promising results, no biomechanical study evaluates and quantifies their mechanical efficacy and safety. METHODS: Two commercial versions of flexible cones were analyzed in this study using finite element analysis, based on a previously validated model. Each cone geometry was modeled both as flexible and as rigid, and implanted following surgical guidelines. Three activities were simulated in this study and compared among configurations: surgical impaction, walking, and chair rise. RESULTS: During impaction, results showed considerably reduced stress in the flexible cones in comparison with rigid ones; the stress resulted was also better distributed and more homogeneous all over the cortical bone, with lower bone peaks. Considering the 2 different activities, the analysis did not show any remarkable differences between flexible and rigid cones both in terms of bone stress and implant micromotion. CONCLUSIONS: The findings demonstrate that metaphyseal flexible cones allow macrodeformation during impaction due to their flexibility, and therefore, are safer in comparison with rigid cones. However, for the daily tasks investigated, results showed no major differences between rigid and flexible cones in terms of bone stress, implant stability, and micromotion. Therefore, their mechanical performances can be considered similar to the rigid cone.

Osseointegration Potential Assessment of Bone Graft Materials Loaded with Mesenchymal Stem Cells in Peri-Implant Bone Defects.

Many studies have been exploring the use of bone graft materials (BGMs) and mesenchymal stem cells in bone defect reconstruction. However, the regeneration potential of Algipore (highly purified hydroxyapatite) and Biphasic (hydroxyapatite/beta-tricalcium phosphate) BGMs combined with bone marrow-derived mesenchymal stem cells (BMSCs) remains unclear. Therefore, we evaluated their osseointegration capacities in reconstructing peri-implant bone defects. The cellular characteristics of BMSCs and the material properties of Algipore and Biphasic were assessed in vitro. Four experimental groups-Algipore, Biphasic, Algipore+BMSCs, and Biphasic+BMSCs-were designed in a rabbit tibia peri-implant defect model. Implant stability parameters were measured. After 4 and 8 weeks of healing, all samples were evaluated using micro-CT, histological, and histomorphometric analysis. In the energy-dispersive X-ray spectroscopy experiment, the Ca/P ratio was higher for Algipore (1.67) than for Biphasic (1.44). The ISQ values continuously increased, and the PTV values gradually decreased for all groups during the healing period. Both Algipore and Biphasic BGM promoted new bone regeneration. Higher implant stability and bone volume density were observed when Algipore and Biphasic BGMs were combined with BMSCs. Biphasic BGM exhibited a faster degradation rate than Algipore BGM. Notably, after eight weeks of healing, Algipore with BSMCs showed more bone-implant contact than Biphasic alone (p < 0.05). Both Algipore and Biphasic are efficient in reconstructing peri-implant bone defects. In addition, Algipore BGM incorporation with BSMCs displayed the best performance in enhancing implant stability and osseointegration potential.

Correlation Between Acquisition of Dental Implant Stability and Hounsfield Units at Dental Implant Placement.

Alveolar bone quality at the implantation site affects the initial stability of dental implant treatment. However, the relationship between bone quality and osseointegration has yet to be evaluated. Herein, we aimed to investigate the effect of bone quality on dental implant stability in osseointegration formation changes. Patients underwent computed tomography imaging before dental implantation at the posterior. Hounsfield units were measured at the platform, middle, and tip sites. Implant stability was measured using resonance frequency analysis immediately and at 3 months postoperatively, in which the difference in implant stability quotients (ISQ) was defined as the change between primary and secondary fixation. In multiple regression analysis, the dependent variable was the change between the immediate and secondary fixations. We included 81 implants that conformed to the criteria. Primary fixation yielded the following results: R2 = 0.117, F = 2.529, and P = .047. The difference between the maxilla and mandible of the implantation site (P = .02) and the platform-site Hounsfield units (P = .019) were identified as significant factors. The following results were obtained regarding the change between the immediate and secondary fixation: R2 = 0.714, F = 40.964, and P < .001. The difference between diameter (P = .008) and the immediate ISQ (P < .001) were identified as significant factors. Overall, the bone quality of the implantation site affected initial fixation; however, it had limited effect on secondary fixation. Our findings clarified the period where bone quality affects dental implant treatment and is expected to advance dental implant treatment.

Influence of titanium and titanium-zirconium alloy as implant materials on implant stability of maxillary implant retained overdenture: a randomized clinical trial.

BACKGROUND: Long-term success of implant restoration depends on many factors one of them is the sufficient implant stability which is lowered in compromised bone density sites such as the maxilla as it is categorized as type III & IV bone, so searching for a new innovation and updates in implant material and features is very mandatory. So, the aim of this study was to compare between two implant materials (roxolid and traditional titanium) on the primary and secondary stability of implant retained maxillary overdenture. METHODS: Eighteen completely edentulous patients were selected. All patients received maxillary implant-retained overdentures and lower complete dentures; patients were divided equally into two groups according to the type of implant materials. Group A received a total number of 36 implants made of roxolid material and Group B received a total number of 36 implants made of traditional titanium alloys. Implant stability was assessed using ostell device, the primary implant stability was measured at the day of implant installation however, secondary implant stability was measured after six weeks of implant placement. Paired t-test was used to compare between primary and secondary stability in the same group and an independent t-test was used to compare between the two groups with a significant level < 0.05. RESULTS: Independent t-test revealed a significant difference between the two groups with p -value = 0.0141 regarding primary stability and p-value < 0.001 regarding secondary stability, as roxolid implant group was statistically higher stability than titanium group in both. Paired t- test showed a statistically significant difference in roxolid implant group with p-value = 0.0122 however, there was non-statistically significant difference in titanium group with p-value = 0.636. Mann Whitney test showed a significant difference between the two groups regarding amount of change in stability with p value = 0.191. roxolid implant group showed a higher amount of change in stability than the titanium implant group. CONCLUSION: Within the limitation of this study, it could be concluded that: Roxolid implants showed promising results regarding primary and secondary stability compared to conventional Titanium implants and can be a better alternative in implant retained maxillary overdentures. TRIAL REGISTRATION: Retrospectively NCT06334770 at 26-3-2024.

A resonance frequency analysis to investigate the impact of implant size on primary and secondary stability.

Objective: Recent years have seen a rise in the usage of dental implants to restore lost teeth. The stability of a dental implant is the main factor in determining its success. Implant stability is influenced by various factors. Several approaches have been employed clinically to evaluate stability at different time intervals. One non-invasive way to assess implant stability is by resonance frequency analysis. Utilizing the resonance frequency analysis method, this study seeks to understand how implant length and diameter affect primary and secondary stability. Methods: The current prospective study was conducted in the Prosthodontics Department of Institute of Dentistry, CMH Lahore Medical College. The duration of the study was six months. A total of 90 implants of sizes 4.5 x 8.5 mm and 4 x 10mm were placed. Resonance frequency measurements were recorded using Osstell™ AB device for primary stability at implant insertion and at 12 weeks for secondary stability. All the measurements were carried out by only one of the researchers to minimize inter-observer bias. Results: The average primary stability was 70.33±6.60, and the average secondary stability was 71.43±5.44. The data was stratified for age, gender, and implant site, and the mean primary and secondary stability of both sizes didn't show any statistically significant differences. Conclusion: Without forfeiting implant stability, both implant sizes (4 x 10mm and 4.5 x 8.5mm) can be used interchangeably, depending on available space and anatomical constraints.

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.

Conditions for Use and Implementation of Globally-Aligned Versus Local Baseplate Coordinate Systems When Computing Migration Using Radiostereometric Analysis.

Radiostereometric analysis can be used for computing movement of a tibial baseplate relative to the tibia (termed migration) to determine stability of fixation. Quantifying migration in six degrees of freedom requires establishing a coordinate system in which to express the movement. Establishing consistent migration directions among patients and baseplate designs remains challenging. Deviations in imaging alignment (tibia/baseplate alignment during image acquisition) and surgical alignment (baseplate alignment on tibia) will affect computed migrations when using the conventional globally-aligned baseplate coordinate system (BCS) (defined by calibration box). Computing migration using a local BCS (defined by baseplate) may be preferrable. This paper (1) summarizes the migration equations when using a globally-aligned versus local BCS, (2) proposes a method for defining a local BCS, and (3) demonstrates differences in the two BCSs for an example patient whose baseplate has rotational deviations due to imaging or surgical alignments. Differences in migration for the two BCSs ranged from about ±0.5 mm in translations and -0.4 deg to 0.7 deg in rotations. Differences were largest for deviations in internal-external rotation and smallest for deviations in varus-valgus rotation. An example demonstrated that the globally-aligned BCS resulted in migration being quantified as subsidence instead of liftoff, thereby changing fundamental interpretations. Because migrations computed using a local BCS are independent of imaging and surgical alignments and instead characterize migration using baseplate features, a local BCS enhances consistency in migration directions among patients and baseplate designs relative to the interface in which fixation may be compromised.

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.

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.

The Stability of Fixation of Vancouver B2 Periprosthetic Femoral Fractures: Effect of Implantation Technique.

BACKGROUND: Due to increasing volume of total hip arthroplasties, periprosthetic femoral fractures have become a common complication with increased revision burden and perioperative morbidity. The objective of this study was to evaluate the fixation stability of Vancouver B2 fractures treated with 2 techniques. METHODS: A common B2 fracture was created by reviewing 30 type B2 cases. The fracture was then reproduced in 7 pairs of cadaveric femora. The specimens were divided into 2 groups. In Group I ("reduce-first"), the fragments were reduced first, followed by implantation of a tapered fluted stem. In Group II ("ream-first"), the stem was implanted in the distal femur first, followed by fragment reduction and fixation. Each specimen was loaded in a multiaxial testing frame with 70% of peak load during walking. A motion capture system was used to track the motion of the stem and fragments. RESULTS: The average stem diameter in Group II was 16.1 ± 0.4 mm, versus 15.4 ± 0.5 mm in Group I. The fixation stability was not significantly different in the 2 groups. After the testing, the average stem subsidence was 0.36 ± 0.31 mm and 0.19 ± 0.14 mm (P = .17) and the average rotation was 1.67 ± 1.30° and 0.91 ± 1.11° (P = .16) in Groups I and II, respectively. Compared to the stem, there was less motion of the fragments and there was no difference between the 2 groups (P > .05). CONCLUSIONS: When tapered fluted stems were used in combination with cerclage cables for treatment of Vancouver type B2 periprosthetic femoral fractures, both the "reduce-first" and "ream-first" techniques showed adequate stem and fracture 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.

The Effect of Osseodensification on Ridge Expansion, Intraosseous Temperature, and Primary Implant Stability: A Pilot Study on Bovine Ribs.

Osseodensification is a novel technique based on nonsubtractive drilling to preserve and condense bone during osteotomy preparation. The aim of this ex vivo study was to compare osseodensification and conventional extraction drilling technique with regard to intraosseous temperatures, expansion of alveolar ridge width, and primary implant stability using different implant geometries: tapered and straight walled. A total of 45 implant sites were prepared in bovine ribs following osseodensification and conventional protocols. Changes in intraosseous temperatures were recorded at 3 depths using thermocouples, and ridge width was measured at 2 different depths before and after osseodensification preparations. The primary implant stability was measured using peak insertion torque and the implant stability quotient (ISQ) following placement of straight and tapered implants. A significant change in temperature was recorded during site preparation for all techniques tested but not at all depths. Osseodensification recorded higher mean temperatures (42.7°C) than conventional drilling, particularly at the midroot level. Statistically significant ridge expansion was observed at both the crestal and apical levels in the osseodensification group. The ISQ values were significantly higher only for tapered implants placed in osseodensification sites when compared with conventional drilling sites; however, there was no difference in the primary stability between tapered and straight implants within the osseodensification group. Within the limitations of the present pilot study, osseodensification was found to increase the primary stability of straight-walled implants without overheating the bone and significantly expanded the ridge width. However, further investigation is required to determine the clinical significance of the bone expansion created by this new technique.

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.

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.