Insertion Torque Research Articles

Autogenous Symphyseal versus Retromolar grafts for 3D augmentation of Anterior Maxillary Deficiencies

Objective: To Compare and contrast different intraoral autogenous grafts for 3D reconstruction of atrophic anterior maxillae, to receive dental implants. Patients & Methods: Twelve patients suffering from anterior maxillary bone resorption and in need for bone augmentation to be able to place dental implants were included in this study. Autogenous bone grafts were harvested from either the symphyseal region (Group A) or the retromolar region (Group B). Assessments were performed using CBCT both pre- and post-operatively; as well as, clinically on delayed implant placement. Results: Both groups showed significant bone formation at 4 months postoperatively, and implants were placed with adequate initial stability. Group A, showed significantly higher insertion torque mainly occlusal and midway upon placement than Group B. All cases had uneventful fixed prosthetic loading of implants. Conclusion: Both symphyseal and retromolar intraoral donor graft sites provide successful graft material for anterior maxillary 3D reconstruction, however, the symphyseal grafts despite providing better initial stability for implants, yet, were less perceivable by the patients regarding postoperative pain and oedema; and provided no significant difference regarding successful loading of dental implants with fixed prosthetics.

Ten-year Survival Rate of Cement- and Screw-retained Restorations on Bone-level Dental Implants in Grafted and Non-grafted Sites: A Retrospective Study.

The aim of the present 10-year follow-up study was to assess the survival rate of cement- and screw-retained restorations on dental implants placed in grafted sites. Patients with cement- (group 1) and screw-retained (group 2) restorations on implants placed in grafted sites and patients with cement- (group 3) and screw-retained (group 4) restorations on implants placed in non-grafted sites were included. Demographic data was recorded using a questionnaire, and information regarding implant dimensions, surface characteristics, insertion torque, type of bone graft used, jaw location and duration of implants in function was retrieved from patients' records. These patients were evaluated for peri-implant crestal bone loss (CBL), probing depth (PD), modified plaque index (mPI), and modified bleeding on probing (mBOP). p < 0.05 was considered statistically significant. Eighty-eight partially edentulous individuals (n = 22 in each group) were included. The mean ages of individuals in all groups were comparable in all groups. In each patient, 1 bone-level platform-switched dental implant with moderately rough surfaces was placed using an insertion torque of 30-35 Ncm. In all groups, the length and diameter of implants ranged between 11-14 mm and 4.1-5 mm, respectively. There was no statistically significant difference in mPI, mBoP, PD, and mesial and distal CBR around implants in any of the groups. Bone-level implants restored with cement and screw-retained restorations can possess a stable clinicoradiographic status and remain functional in grafted and non-grafted sites, provided strict domestic oral hygiene measures are adopted and routine dental prophylaxis is carried out by oral healthcare providers.

Comparison of Peri-Implant Clinicoradiographic Parameters among Non-Smokers and Individuals Using Electronic Nicotine Delivery Systems at 8 Years of Follow-up.

It is hypothesised the peri-implant soft-tissue inflammatory parameters (plaque index [PI], gingival index [GI], and probing depth [PD]) are poorer and crestal bone loss (CBL) higher around dental implants placed in electronic nicotine delivery systems (ENDS)-users than controls (individuals that had never consumed any form of tobacco). The aim of this study was to assess the peri-implant clinicoradiographic parameters among non-smokers and individuals using ENDS at 8 years of follow-up. Self-reported non-smokers and individuals habitually using ENDS were included. A questionnaire was used to gather information about age in years, sex (female or male), daily frequency and duration of use of ENDS, family history of smoking and/or vaping, daily toothbrushing and flossing and most recent visit to a dentist or dental hygienist. These patients were evaluated for peri-implant CBL, PD, PI, BOP. The mesial and distal CBL was measured on digital bitewing radiographs that were taken using the long-cone paralleling technique. Group comparisons were statistically assessed and the level of significance was set at p < 0.05. One hundred twenty-seven individuals (92 males and 35 females) were included. Sixty-three individuals (46 males and 17 females) had used ENDS for 9.2 ± 0.8 years (group 1) and 64 (46 males and 18 females) did not use any nicotinic products (group 2). The mean ages of individuals in groups 1 and 2 were 34.2 ± 1.3 and 35.1 ± 0.5 years, respectively. In all patients, platform-switched dental implants with moderately rough surfaces were placed at bone level using an insertion torque of 30--35 Ncm. In both groups, implants had a diameter of 4.1 mm and the lengths ranged between 11 and 14 mm. In groups 1 and 2, implants were in function for 8.8 ± 0.4 and 8.5 ± 0.2 years, respectively. There was no statistically significant difference in mPI, mBoP, PD, and mesial and distal CBL around implants in groups 1 and 2 at 8 years of follow-up. Dental implants can demonstrate stable clinicoradiographic status and can remain functionally stable in non-smokers and ENDS users, provided that strict home oral hygiene measures are adopted.

Resonance frequency analysis of implants placed in condensed bone.

ObjectivesResonance 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 methodsIn 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.ResultsIn 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).ConclusionsRFA is feasible for monitoring stability after late implant placement into condensed bone, but not after immediate placement into condensed fresh extraction sites.

An In Vitro Analysis on Polyurethane Foam Blocks of the Insertion Torque (IT) Values, Removal Torque Values (RTVs), and Resonance Frequency Analysis (RFA) Values in Tapered and Cylindrical Implants

Background: Several different dental implant microgeometries have been investigated in the literature for use in low-density bone sites. The polyurethane solid rigid blocks represent an optimal in vitro study model for dental implants, because their composition is characterized by symmetrical linear chains of monomers of hexa-methylene sequences producing a self-polymerization process. The aim of the present investigation was to evaluate the primary stability of cylindrical and tapered implants positioned into low-density polyurethane solid rigid blocks. Materials and Methods: Two different macrogeometries, cylindrical (4 mm diameter and 10 mm length) and tapered dental implants (4.20 mm diameter and 10 mm length), were investigated in the present study. The implants were inserted into 10 PCF and 20 PCF polyurethane blocks, with and without an additional cortical layer. The insertion torque (IT) values, the removal torque values (RTVs), and the resonance frequency analysis (RFA) values were measured and recorded. Results: A total of 80 sites were tested, and a significant increased primary stability (PS) was detected in favour of tapered dental implants when compared to cylindrical implants in all experimental conditions (p < 0.05). Higher IT, RT, and RFA values were measured in tapered implants in 10 and 20 PCF polyurethane blocks, both with and without the additional cortical layer. Conclusions: Both implants showed sufficient primary stability in poor density substrates, while, on the other hand, the tapered microgeometry showed characteristics that could also lead to clinical application in low-density posterior maxillary sites, even with a drastically decreased bone cortical component.

Early Bone Healing on Hydroxyapatite-Coated and Chemically-Modified Hydrophilic Implant Surfaces in an Ovine Model.

Implant topography affects early peri-implant bone healing by changing the osteoconduction rate in the surrounding biological environment. Implant surfaces have been designed to promote faster and stronger bone formation for rapid and stable prosthesis loading. Early peri-implant bone healing has been observed with a sandblasted, acid-etched implant that was chemically modified to be hydrophilic (cmSLA). The present study investigates whether early peri-implant bone healing extends to a rough surface implant with a high crystalline hydroxyapatite surface (TSV MP-1 HA). Three implants were randomly placed in porous trabecular bone within both medial femoral condyles of 10 sheep. Early peri-implant bone stability was measured at 3- and 6-weeks healing time following implant insertion. Results indicated a similar implant stability quotient between the implants at insertion and over time. The significant increase over time of reverse torque values with respect to insertion torque (p < 0.001) did not differ between the implants. However, the bone-to-implant contact of TSV MP-1 HA was significantly higher than that of cmSLA implants at 6 weeks (p < 0.01). These data validate previous findings of a hydrophilic implant surface and extend the observation of early osseointegration to a rough surface implant in porous trabecular bone.

Influences of screw design features on initial stability in immediate implant placement and restoration

BackgroundSelf-tapping screws have been extensively used for dental implants. Their biomechanical behavior is highly associated with their clinical success, particularly for screws used for immediate implant placement and restoration, because occlusal forces can directly affect the loading transfer at the bone–implant interface after implantation. The effect of implant design on the initial stability of self-tapping screws remains unclear. This study explored the biomechanical behaviors of implant stability in standardized implants with different design features. MethodsSix types of dental implants were designed using computer-aided design/computer-aided manufacturing technology, including three types of cutting flute shapes (spiral, straight, and non–self-tapping) combined with two types of screw features. Peak insertion torque values were first recorded; initial stability levels were subsequently evaluated in terms of the maximum force and resistance to lateral loads using an electrodynamic test system. FindingsThe peak insertion torque values, maximum force, and resistance to lateral loads of the non–self-tapping groups were higher than those of the self-tapping groups by 17%–90% (p < 0.01). The peak insertion torque values of the Straumann implant with a spiral flute was higher than that of the original straight flute by 20% (p < 0.001). However, compared with the original spiral flute, the Nobel Biocare implant with straight flute had a 23% higher maximum force (p = 0.016) and 24.5% higher resistance (p = 0.012) under lateral loading. InterpretationChanging the flute design would affect initial implant stability. Non–self-tapping implants exhibited superior initial stability than did self-tapping implants.

Correlation between bone volume fraction in posterior implant area and initial implant stability

Bone volume fraction (BV/TV) was used as a quantitative indicator of bone mineral density (BMD) in the posterior dental implant area, and the relationship between it and the initial stability of the implant was analyzed. 53 patients with posterior dental implantation were selected. Remove the bone fragments from the planting area and put them in the formalin solution. Then, the implant was placed after the operator prepared the hole step by step. Peak Insertion torque value (ITV) and Implant stability quotient (ISQ) were recorded. The BV/TV of the bone fragments was measured by Image pro Plus6.0. The correlation between it and ITV and ISQ was analyzed. BV/TV was correlated with ITV and ISQ in the posterior dental planting area (r=0.862, r=0.832, P < 0.05). The correlation of the parameters in the posterior part of maxilla was higher than that in the mandible. There were significant differences in BV/TV, ITV, and ISQ between the mandible and maxilla, and the implant area of the mandible was higher than that of the maxilla. BV/TV can provide an objective index for BMD in the implant area, which has an important influence on the evaluation of the initial stability of the implant.

Accuracy of half-guided implant placement with machine-driven or manual insertion: a prospective, randomized clinical study

ObjectivesTo compare the accuracy of implant placement performed with either a surgical motor or a torque wrench as part of a half-guided surgical protocol.Materials and methodsImplant insertion with half-guided surgical protocol was utilized by surgical motor (machine-driven group) or torque wrench (manual group) in the posterior maxilla. After the healing period, accuracy comparison between planned and actual implant positions was performed based on preoperative cone beam computed tomography and postoperative digital intraoral scans. Coronal, apical, and angular deviations, insertion time, and insertion torque were evaluated.ResultsForty patients were treated with 1 implant each; 20 implants were inserted with a surgical motor and 20 implants with a torque wrench. Global coronal and apical deviations were 1.20 ± 0.46 mm and 1.45 ± 0.79 mm in the machine-driven group, and 1.13 ± 0.38 mm and 1.18 ± 0.28 mm in the manual group (respectively). The mean angular deviation was 4.82 ± 2.07° in the machine-driven group and 4.11 ± 1.63° in the manual group. Mean insertion torque was 21.75 ± 9.75 Ncm in the machine-driven group, compared to 18.75 ± 7.05 Ncm in the manual group. Implant placement duration was 9.25 ± 1.86 s in the machine-driven group at a speed of 50 rpm, and 36.40 ± 8.15 s in the manual group.ConclusionNo significant difference was found between the two groups in terms of accuracy and mean insertion torque, while machine-driven implant placement was significantly less time-consuming.Clinical relevanceOptimal implant placement accuracy utilized by half-guided surgical protocol can be achieved with both machine-driven and torque wrench insertion.Trial registrationID: NCT04854239

Influence of implant geometry and osteotomy design on early bone healing: A pre‐clinical in vivo study

To analyze the early stages of osseointegration around implants with different geometry following installation in sites using different osteotomy protocols. Two types of implants were installed using regular or modified (reduced diameter) osteotomy protocols in mandibular premolar/molar regions following tooth extraction in six dogs. Three implant site categories were created: Reference (A implant and regular osteotomy), Test-1 (B implant and regular osteotomy), and Test-2 (B implant and modified osteotomy). Implant installation procedures were repeated after 4 and 6weeks. The insertion torque (ITQ) was measured during implant installation and resonance frequency analysis providing implant stability quotient (ISQ) values was performed following implant installation and once every week during the course of the study. Biopsies were obtained immediately after the 3rd installation procedure and prepared for histological analysis. The modified osteotomy protocol created a higher insertion torque (ITQ). The analysis also revealed a correlation between insertion torque at implant installation and radiographic bone loss after 6weeks of healing. The decline in ISQ values during healing was more pronounced at Test-2 than other sites. While the degree of bone-to-implant contact (BIC%) in the marginal area was similar in test and reference sites at 6weeks of healing, Test-2 implants presented with a significantly higher BIC% in the mid and apical areas than Test-1 implants. It is suggested that placement of implants in undersized osteotomy sites will result in an increased remodeling of the cortical bone during the early healing process.

Immediate loading of fixed partial prostheses reconstructed using either tapered or straight implants in the posterior area: A randomized clinical trial.

In immediately loaded implants within 72 h after the implant placement in the unilaterally and partially edentulous ridge, primary stability is considered critical, which can be influenced by the design of the implant fixture. To determine the outcomes at 1year after the immediate loading of multiunit fixed partial prostheses over either tapered implants (TIs) or straight implants (SIs) in the posterior region. Forty-eight patients (24 patients, 52 implants in TI group; 24 patients, 50 implants in SI group) were included for the study. Except for the one SI group patient whose two implants showed the insertion torque less than 30 Ncm, provisional prostheses designed and fabricated from intraoral scan data obtained immediately after implant surgery were delivered to rest of the 47 subjects at 3-7 days. After a year, the survival rate was estimated by intention-to-treat (ITT) and per-protocol (PP) analyses, and marginal bone loss (MBL) and implant stability were also analyzed statistically (p < 0.05). Survival rate at implant level in TI group was 96.2%, and that of SI group in the ITT analysis was 86.0%. Intergroup difference, however, was not statistically significant (p > 0.05). Insertion torque was significantly higher in TI group than SI group (47.12 ± 6.37 Ncm vs. 41.60 ± 9.77 Ncm; p < 0.05). MBLs of both groups were less than 0.1 mm at 1-year follow-up and was similar between two groups (p > 0.05). Immediate loading of fixed partial prostheses after TI and SI placement showed reliable outcomes in the partially edentulous posterior ridge. In terms of the initial mechanical stability, the performance was superior for TIs than for SIs.

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

Evaluation and comparison of insertion torque (IT) and the implant stability of two different implant macrogeometry in different bone densities using resonance frequency analysis. 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. 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. 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. 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.

Effect of surface treatment on the mechanical stability of orthodontic miniscrews.

To provide collective quantitative evidence about the effect of surface treatments on the mechanical stability of orthodontic miniscrews (MSs). The study was registered in PROSPERO (No. CRD42020209652). The research question was defined according to the PICO (population, intervention, control, and outcomes) format. Various research databases were searched for animal and human studies on effects of surface treatment on the mechanical stability of MSs. Both prospective and retrospective in vivo clinical studies published in English were included. The risk of bias was assessed using SYRCLE's risk of bias tool for animal studies. The meta-analysis was conducted using RevMan 5.4. A total of 109 articles were identified; 14 were included in the systematic review, and seven studies with sandblasting, acid etching (SLA) methods of surface treatment were included for meta-analysis. The number of study participants ranged from 6 to 24 (total n = 185), with a mean of 13.2. A total of 949 MSs were used with a mean of 67.8. The overall success rate for surface-treated MSs ranged from 47.9% to 100%. Forest plot of removal torque values showed significantly higher values for SLA surface-treated MSs compared with controls with a standard mean difference of 2.61 (95% confidence interval = 1.49-3.72, I2 = 85%). Forest plot of insertion torque showed a standard mean difference of -6.19 (95% confidence interval = -13.63-1.25, I2 = 98%, P = .10). Surface treatment of MSs improved primary and secondary stability with good osseointegration at the bone-implant surface. However, significant heterogeneity across the studies included in the meta-analysis made it difficult to draw conclusions.

Dental Implant for Maxillary Cancellous Alveolar Bone with Expandable Transformation in Apical Part.

The focus of this study is to propose a new implant design that will resemble the tooth anatomy as with three roots thus increase the primary stability in bone and open new indications to dental implant applications. Developed implant design and control implants were fabricated from Grade 4 type medical titanium. Three different media are selected as similar structural mechanical properties of alveolar cancellous bone quality; bovine iliac bone, bovine spinal bone, and polymer block. Implant sites were prepared with a 2-mm final drill. Then implants were inserted and all insertion torques were recorded. Starting from 5 Ncm implants were applied removal torques to test the initial stability. The sample that withstands the removal torque is marked with "+" until the torque value where the implant started to move out from the bone socket. Different bone structures and polymer material, designed implant with apical arms have shown relatively average gains of % 38.6 in bovine spinal bone samples, % 38.2 in bovine iliac bone samples and % 46.4 gain in polymer block in retention to removal torques. In the Bovine spinal bone environment, the percentage of gain of the Implant Group developed was significantly higher than the Control Implant Group (p: 0.000; P < 0.05). In the Bovine iliac bone medium, the percentage of gain of the Implant Group developed was significantly higher than the Control Implant Group (p: 0.002; P < 0.05). In the Polymer block environment, the gain percentage of the Implant Group developed was significantly higher than the Control Implant Group (p: 0.008; P < 0.05). The results of this study indicate promising positive future directions to make further researches on the material production and testings of such a new dental implant design including in vivo clinical controlled studies will be beneficial for better understanding the behavior of the developed implant design under different conditions.

HEAT GENERATION DURING IMPLANT PLACEMENT IN HIGH-DENSITY BONE: EFFECT OF DIFFERENT DRILLING TECHNIQUES

ABSTRACT Introduction: A precise drilling-sequence-protocol is essential for long-term dental implant success in high bone density (mandibular cortical bone of D1-quality). Cone beam computed tomography (CBCT) radiographic imaging and CBCT-based construction of surgical guides have been substantial for diagnosis and treatment planning. Objectives: The study aimed to measure the effect of different guided drilling techniques on the amount of heat generated during implant placement in high density. Materials and Methods: Twenty-four osteotomies for implant placement, divided equally into three groups, to test the effect of the three drilling techniques Undersized Drilling (UD), Undersized Drilling + Ridge Spreader size 4 (UD+RS4) and Undersized Drilling + counter sink size 4 (UD+CS4) techniques. Heat generation was assessed using K-type thermocouple. Drilling and thermocouple canals were guided by the surgical template. Bone assessment, virtual planning of the implants and surgical guide construction were based on radiographic CBCT-imaging and software-based processing. Insertion torque values (ITVs) were recorded from readings of a geared motor. Results: The thermocouple results showed the least significant difference at 10 mm depth. At 5mm depth, a significant decrease in the temperature difference of the UD+RS4 group and UD+CS4 group compared to UD group was observed. At 1mm depth, there was a significant difference between the UD group and the two other groups. The UD group showed the maximum peak ITV. Conclusion: the results suggest possible advantages when self-tapping implants are inserted into high density cortical bone of D1-quality by a countersink drill since it provides lesser temperature increase at insertion.

Osseodensification enables bone healing chambers with improved low-density bone site primary stability: an in vivo study

Primary implant stability is a prerequisite for successful implant osseointegration. The osseodensification technique (OD) is a non-subtractive drilling technique that preserves the bone tissue, increases osteotomy wall density, and improves the primary stability. This study aimed to investigate the hypothesis that OD, through a wider osteotomy, produces healing chambers (HCs) at the implant-bone interface without impacting low-density bone primary stability. Twenty implants (3.5 × 10 mm) with a nanohydroxyapatite (nHA) surface were inserted in the ilium of ten sheep. Implant beds were prepared as follows: (i) 2.7-mm-wide using subtractive conventional drilling (SCD) technique (n = 10); (ii) 3.8-mm-wide using an OD bur system (n = 10). The sheep were randomized to two groups, with samples collected at either 14-(n = 5) or 28-days (n = 5) post-surgery and processed for histological and histomorphometric evaluation of bone-implant contact (BIC) and bone area fraction occupancy (BAFO). No significant group differences were found with respect to final insertion torque and implant stability quotient (p > 0.050). BIC values were higher for SCD after 14 and 28 days (p < 0.050); however, BAFO values were similar (p > 0.050). It was possible to conclude that the OD technique allowed a wider implant bed preparation without prejudice on primary stability and bone remodeling.

Resonance frequency analysis with two different devices after conventional implant placement with ridge preservation: A prospective pilot cohort study.

Primary and secondary implant stability is of high importance for survival and success of dental implants in the short and long term. Measurements of implant stability during healing provide the opportunity to monitor the course of the osseointegration process. To compare implant stability quotient (ISQ) by resonance frequency analysis (RFA), recorded with two different devices after implant placement. Patients with the need of single tooth extraction in posterior sites of the maxilla and the mandible were treated in a surgical center. All patients received additional augmentation with a bovine bone substitute and platelet-rich fibrin (PRF) after atraumatic tooth extraction. After a healing period of 10 weeks, 28 self-tapping titanium-implants were placed. Implant stability was recorded with two different devices (Osstell and Penguin) at the time of implant insertion (T0), 10 days later (T1), and after 7 (T2), or 17 weeks (T3). No implant was lost, and no postoperative complication occurred during follow-up. Patient cohort comprised 9 female (32.1%) and 19 male patients (67.9%), with a mean age of 52.8 years, 64.3 years, respectively. Mean overall insertion torque was 43.6Ncm at implant placement with no significant difference between implant location, age, or gender. No patient dropped out. During observation period, a significant increase in mean ISQ was recorded with both devices. Significant positive correlations between insertion torque and ISQ were recorded with both devices at T0, T2, and T3. No significant differences were observed in ISQ-values between both devices, and measuring directions at any point of measurement. Within the limitations of this cohort study, both devices were suitable for RFA-measurement and revealed comparable results. Due to the cordless design, handling of the Penquin device was more comfortable. Reusability of the Penguin MultiPeg-transducers may offer an additional benefit with regard on ecological aspects.

Effect of hydroxyapatite tubes on the lag screw intraoperative insertion torque for the treatment of intertrochanteric femoral fractures

BackgroundHydroxyapatite (HA) augments are frequently used in orthopedic surgery. However, the effectiveness of HA augments on the treatment of intertrochanteric femoral fractures remains unknown. This study aimed to investigate whether the use of HA tubes affects the intraoperative insertion torque of the lag screw during intertrochanteric femoral fracture surgery. MethodsFrom January 2016 to October 2020, 58 patients with intertrochanteric femoral fractures were included and divided into the HA treatment group (HA group, n = 29) and non-HA treatment group (N group, n = 29). Patients with intertrochanteric femoral fractures were treated using the Gamma3 nail system® with or without two HA tubes. HA tubes were inserted into the femoral head through the lag screw hole before the insertion of the lag screw. The mean and maximum intraoperative insertion torques of the lag screw, bone mineral density (BMD) of the uninjured opposite side femoral neck, and tip apex distance (TAD) of the lag screw on postoperative radiographs were assessed. To assess the loss of reduction after the surgery, we investigated the amounts of telescoping of the lag screw and the changes in the neck shaft angle. ResultsThe mean and maximum insertion torques were correlated with BMD in the HA and N groups, respectively. The mean and maximum insertion torques were not correlated with TAD in the HA and N groups, respectively. The mean torque/BMD ratio was significantly higher in the HA group than in the N group (p = 0.03). There were no significant differences in the maximum torque/BMD ratio between HA and N groups (p = 0.06), while the maximum torque/BMD ratio tended to be higher in the HA group than in the N group. The amounts of telescoping of the lag screw in the HA group were significantly lower than that in the N group (p = 0.04), while there were no significant differences in the changes in the neck shaft angle between two groups (p = 0.32). ConclusionOur results strongly suggest that the use of HA tubes increases the intraoperative lag screw insertion torque/BMD ratio and may improve the lag screw fixation by strengthening the bone/metal thread interface in the treatment of intertrochanteric femoral fractures.

COMPARATIVE EVALUATION OF OSSEODENSIFICATION EFFECT ON PERI-IMPLANT STRAIN WHILE LOADING A FOUR UNIT CERAMIC FIXED PARTIAL DENTURE (IN VITRO STUDY)

Introduction: Primary stability and bone quality are key factors in implant success in early stages of placement while osseointegration comes further on. Objectives: The aim of this study was to compare the effect of osseodensification on peri-implant strain during functional loading of a 4-unit monolithic zirconia bridge as well as its effect on primary stability and insertion torque. Materials and Methods: Sixteen IS-II active implants were used in this study, the implants were divided into 2 groups. Group (A) were placed in conventionally drilled osteotomy sites with progressive subtractive enlargement and Group (B) were placed in osseo-densified osteotomy sites. All implants were inserted in unicortical polyurethane test blocks mimicking medium quality bone while recording insertion torque and implant stability quotient (ISQ) using Osstell for all implants. Each block contained two parallel implants carrying a 4-unit fixed partial denture (FPD). FPD were cemented then thermocycled for 5000/cycle and mechanically loaded at 100N, 2.5×10*5 cycles. A load of 400N and 600N and 800N was applied at connector areas in FPD. Strain gauges were connected to strain meter to record the peri-implant strain for both implants in all groups. Results: Regarding insertion torque and peri-implant insertion torque strain Group (A) had significantly lower values than group B (p < 0.05) while insignificant Osstell values. Concerning peri-implant strain after loading group A had significantly higher strain values than Group (B) (p < 0.05). Conclusions: Osseodensification drilling protocol increased insertion torque values and peri-implant insertion torque strain in comparison to conventional drilling protocol while decreasing peri-implant strain after loading.

Relation Between Insertion Torque and Implant Stability Quotient: A Clinical Study.

Objectives This study aimed to assess the relation between the insertion torque and implant stability quotient (ISQ recorded immediately and 6 months after implant placement). Materials and Methods Twenty-five patients over the age of 18 years were selected for this study. One implant was placed per patient after tooth extraction. All implants had the same size (11.5 × 3.75 mm) and brand (Hexagonal Morse cone, DSP Biomedical). The insertion torque (Ncm) and resonance frequency analysis (ISQ value) (Osstell Mentor) were used to assess the primary stability (on the day of surgery). After 6 months, resonance frequency analysis was used to assess the secondary stability of each implant. Statistical Analysis The insertion torque data were correlated with ISQ measurements by using Pearson’s correlation. The significance level was 5%. Results There was a positive correlation between insertion torque and initial ISQ (correlation: 0.457; p = 0.022); however, no correlation was found between insertion torque and final ISQ ( p = 0.308). Conclusion The present study demonstrated that there is a positive correlation between the insertion torque and the initial ISQ. Therefore, the higher the insertion torque, the higher the initial ISQ (and vice versa).