Difference In Primary Stability Research Articles

Nondestructive acoustic modal analysis for assessing bone screw stability: An ex vivo animal study.

Conventional insertion torque and pull-out tests are destructive and unsuitable for clinical bone screw fixation. This study evaluates screw stability using acoustic modal analysis (AMA) and Periotest compared to traditional methods in an ex vivo animal model. Titanium self-tapping screws (STS) and nonself-tapping screws (N-STS) were implanted in the proximal tibia of 12 rabbits. Four testing methods were used to assess screw stability: peak insertion torque (PIT) during implantation, AMA for natural frequency (NF), Periotest for Periotest value (PTV), and pull-out test for peak pullout force (PPF). Euthanization was performed at 0 (primary stability), 4, and 8 weeks (secondary stability). No significant difference in primary stability was found between STS and N-STS except for AMA (STS: NF 2434 ± 67 Hz, N-STS: NF 2572 ± 43 Hz; p = 0.62). Secondary stability increased significantly over time for both screw types (4-week: NF 3687 ± 36 vs. 3408 ± 45 Hz, PTV 1.4 ± 1.6 vs. -1.5 ± 1.8, PPF 236 ± 29 vs. 220 ± 34 N; 8-week: NF 3890 ± 39 vs. 3613 ± 31 Hz, PTV -3.2 ± 2.5 vs. -2 ± 4.3, PPF 248 ± 25 vs. 289 ± 28 N). Higher NF values for given PTV/PPF indicate potential clinical advantages. Significant differences between primary and secondary stabilities suggest osteointegration was mainly achieved in the 4-week group.

The effect of a collar on primary stability of standard and undersized cementless hip stems: a biomechanical study

IntroductionAseptic loosening and periprosthetic fractures are main reasons for revision after THA. Quite different from most other stem systems, Corail cementless hip stems show better survival rates than their cemented counterpart, which can possibly be explained by the use of a collar. The study aimed to investigate primary stability with standard and undersized hip stems both collared and collarless.Materials and methodsPrimary stability of cementless, collared and collarless, femoral stems was measured in artificial bones using both undersized and standard size. After preconditioning, 3D micromotion was measured under cyclic loading at the bone-implant interface.ResultsThe use of a collar resulted in higher micromotion within the same stem size but showed no statistically significant difference for both standard and undersized hip stems. The collared and collarless undersized stems showed no significant differences in 3D micromotion at the upper measuring positions compared to the standard stem size. Micromotion was significantly higher in the distal measuring positions, with and without collar, for the undersized stems (vs. standard collarless stem size).ConclusionThe key finding is that the collarless and collared Corail hip stems, within one stem size, showed no significant differences in primary stability. Undersized stems showed significantly higher micromotion in the distal area both with and without collar.

An In Vivo Comparative Study between Primary Stability of Dental Implant in D3 and D4 Bone with different Implant Designs

Purpose: The purpose of the study is to assess the difference in primary stability and insertional torque in D3 and D4 bone densities in relation to conical and tapered cylindrical conical implant designs. Implant designs, commonly available as conical tapered thread design presented a similar survival rate in D1 and D2 bone but questionable results were there in D3 and D4 bone. But while placing tapered cylindrical conical implants in D3, D4 bone presented better primary stability and insertional torque upto 40+ N with excellent stability

Effectiveness of the photobiomodulation therapy using low-level laser around dental implants: A systematic review and meta-analysis.

The photobiomodulation (PBM) therapy has been applied in various fields. Its use in implant dentistry has been proven through various animal, in vitro, and recently also clinical studies. However, the cumulative data of its effect around dental implants in patients is limited. The purpose of the present study was to evaluate whether or not the PBM therapy has a positive effect around dental implants and on implant stability. The studies included in the review and meta-analysis were selected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the PICOS criteria. The RoB 2 tool was used for assessing the risk of bias and the RevMan software, v. 5.0, was used for meta-analysis. Quantitative analysis was done considering the implant stability measurement as the outcome. The mean and standard deviation (M ±SD) values for implant stability as well as the sample size were extracted from the articles, and the inverse variance method with random effects was used for meta-analysis. The forest plots for all time intervals were inspected to estimate the heterogeneity by assessing the I2 statistic. A total of 148 articles were initially retrieved, out of which 81 remained after duplicate removal. Ten articles were included in the review after rejecting 68 on the basis of title and abstract. Seven were eligible for quantitative analysis. The meta-analysis showed non-significant differences in primary stability in control and laser groups at baseline (p = 0.63) and 3 months and above (p = 0.06). At 2 weeks, 1 month and 2 months, the results were statistically significant with p = 0.01, p = 0.02 and p = 0.04, respectively. The PBM therapy showed a positive effect on implant stability during the early stages of healing and can be considered for patients with dental implants.

Influence of Clinical Parameters on the Primary Stability of a Tapered Dental Implant: A Retrospective Analysis.

The aim of this study was to investigate the influence of different clinical parameters on the primary stability of a variable thread tapered implant system with a focus on surgical undersizing protocols. This retrospective study evaluated patients who received NobelActive implants in a single institution. The relationship between the independent variables, bone quality, implant diameter, implant length, implantation time, region of the jaw, and surgical undersizing protocol, and the dependent variable, maximum insertion torque, was investigated. Statistical analysis was conducted using analysis of variance (ANOVA) and multiple linear regression. A total of 1,292 implants placed in 574 fully or partially edentulous patients were evaluated. For the total sample size, without further differentiation between bone qualities, statistically significantly higher primary stability values were shown for an 8% to 9% undersized group (50.33 ± 17.16 Ncm), compared with a 16% undersized group (41.88 ± 17.63 Ncm), a 20% undersized group (33.65 ± 15.78 Ncm), a 26% to 28% undersized group (34.53 ± 15.49 Ncm), and a 35% to 44% undersized group (32.78 ± 18.80 Ncm). No statistical differences were found for undersizing protocols in bone quality 4. Bone quality had the highest influence on primary stability (Welch-Test F(3, 65.57) = 119.48, P < .001, η2 = .20). Contrary to the other investigated independent variables, no statistically significant differences in primary stability were found for the different implantation times. Undersizing protocols exceeding 8% to 9% do not seem to enhance primary stability values. Further studies are needed to investigate the biologic consequences of undersizing, including the impact of implant design characteristics.

The assessment of the effect of the size of lateral-antrostomy in graftless balloon elevation of the maxillary sinus membrane with simultaneous implant placement (a randomized controlled clinical trial).

The overlying maxillary sinus frequently restrains the height of the posterior maxillary bones. Evaluating the effect of downsizing the antrostomy side-window on the stability of the installed implants and vertical bone gain, after employing a graftless antral membrane balloon elevation (AMBE). The study is a randomized controlled clinical trial conducted on 20 patients with 30 deficient maxillary alveolar ridges underwent graftless (AMBE) after being allocated into a (5 mm) entry antrostomy group (the test group) and a (10 mm) entry antrostomy group (the control group) implementing a radiographic linear bone height and implant stability quotations (ISQ) comparison among both groups immediately after the placement of 38 Implants and 6 months after. Radiographic bone gain of the test group (5.55 ± 0.93 mm) was significantly higher than the control group (2.86 ± 0.60 mm) (p <0.001). There was no significant difference in primary stability between the test (65 ± 5.32) and control groups (62.67 ± 4.46) (p = 0.202); while the test group (73.43 ± 4.39) showed significantly higher secondary stability than the control group (64.83 ± 6.05) (p <0.001). ISQ values recorded at 6 months were significantly higher than those recorded at insertion in the test group (p <0.001), while they were insignificant in the control group (p = 0.148). Undersizing the antrostomy window deemed beneficial concerning the vertical bone gain and the simultaneously placed root form dental implants' secondary stability.

In-vitro evaluation of the primary stability of multiple condensing thread designed implants placed by novice and experienced clinicians

Abstract The null hypothesis was that there is no difference in primary stability (PS) of Multiple Condensing Thread Designed (MCTD)-implants placed in simulated type-IV bone by trainee and experienced operators. The aim was to compare the performance of a novice and an expert clinician in assessing the PS of MCTD-implants placed in simulated type-IV bone-blocks using the ridge expansion (spreading) and bone condensation techniques. The MCTD (n=120) implants were placed in cellular rigid polyurethane foam bone-blocks by an undergraduate student (n=60 implants) and an expert (n=60 implants), respectively. Each operator independently performed the osteotomies, which were sub-classified into three groups (20 implants/group): Group-1—Conventional osteotomy; Group-2: Osteotomy and condensation with a tapered osteotome; and Group-3—osteotomy condensed with cylindrical osteotomes. The PS was measured using insertion torque (IT), resonance frequency analysis (RFA) and Periotest values (PTV). P

Dynamic trial fitting by an expanding trial cup does not jeopardize primary acetabular component stability

BackgroundTrial fitting of the acetabular component in uncemented total hip replacement is traditionally done by trial cups. Since trial cups do not resemble the real press-fit obtained by the definitive cup, a dynamic trial inserter, called the X-pander ®, was developed to mimic the real amount of press-fit. However, the concern is raised of losing the initial press-fit by using the X-pander® due to pre-expansion of the acetabulum. The purpose of this study was to assess if there is a difference in primary stability between both methods. MethodsA biomechanical randomized study was performed with bovine calf acetabula, with randomization between either using the X-pander® or the traditional trial cups to assess primary stability. The primary outcome was the force needed to achieve lever out of the implanted cup (Anexys, Mathys or Trident, Stryker), measured in Newton meter (Nm) with a biomechanical testing set up. FindingsIn total, 54 cups (19 Anexys, 35 Trident) were inserted and tested after randomized trial fitting. Overall mean lever out was 45.1 Nm (SD 14.6) for the X-pander® group and 45.0 Nm (SD 14.5) for the trial cups group. After adjustment for potential confounders (cup size and type) mixed model analysis did not reveal a significant difference in lever out force between both testing devices (mean 1.0 Nm, 95%CI (−5.9; 8.0), p = .77). InterprationInitial press-fit of the implanted cup is not lost by pre-expansion as done with dynamic trial fitting with the X-pander®.

Comparison of the Primary Stability of Porous Tantalum and Titanium Acetabular Revision Constructs.

Adequate primary stability of the acetabular revision construct is necessary for long-term implant survival. The difference in primary stability between tantalum and titanium components is unclear. Six composite hemipelvises with an acetabular defect were implanted with a tantalum augment and cup, using cement fixation between cup and augment. Relative motion was measured at cup/bone, cup/augment and bone/augment interfaces at three load levels; the results were compared to the relative motion measured at the same interfaces of a titanium cup/augment construct of identical dimensions, also implanted into composite bone. The implants showed little relative motion at all load levels between the augment and cup. At the bone/augment and bone/cup interfaces the titanium implants showed less relative motion than tantalum at 30% load (p < 0.001), but more relative motion at 50% (p = n.s.) and 100% (p < 0001) load. The load did not have a significant effect at the augment/cup interface (p = 0.086); it did have a significant effect on relative motion of both implant materials at bone/cup and bone/augment interfaces (p < 0.001). All interfaces of both constructs displayed relative motion that should permit osseointegration. Tantalum, however, may provide a greater degree of primary stability at higher loads than titanium. The clinical implication is yet to be seen

Primary Stability in Cementless Rotating Platform Total Knee Arthroplasty.

Highly porous ingrowth surfaces have been introduced into tibial tray fixation to improve long-term survivorship in cementless total knee arthroplasty. This study was designed to evaluate the effect of porous ingrowth surface on primary stability in the implanted cementless tibial component. Three tibial tray designs possessing sintered bead or roughened porous coating ingrowth surfaces were implanted into a foam tibia model with primary stability assessed via digital image correlation during stair descent and condylar liftoff loading. Follow-up testing was conducted by implanting matched-pair cadaveric tibias with otherwise identical trays with two iterations of ingrowth surface design. Trays were loaded and micromotion evaluated in a condylar liftoff model. The sintered bead tibial tray exhibited slightly lower micromotion than the roughened porous coating in stair descent loading. However, no significant difference in primary stability was observed in condylar liftoff loading in either foam or cadaveric specimens. Cementless tibial trays featuring two different iterations of porous ingrowth surfaces demonstrated both good stability in cadaveric specimens with less than 80 microns of micromotion and 1 mm of subsidence under cyclic loading. While improved ingrowth surfaces may lead to improved biological fixation and long-term osteointegration, this study was unable to identify a difference in primary stability associated with subsequent ingrown surface design iteration.

The Influence of Implant Shape on Primary Stability of Implants With a Thread Cutting and Forming Design: An Ex Vivo Study.

The design of an implant has a great effect on primary stability. The purpose of this study was to determine the differences in primary stability between straight and tapered Neoss ProActive implants in type I and type III bones using resonance frequency analysis (RFA) and electronic percussive testing (EPT) methods. Fresh cow vertebrae and pelvis were used as models of type III and type i bone, respectively. Implants of 2 different designs-straight and tapered Neoss ProActive implants with a thread cutting and forming (TCF) design, both 3.5-mm wide and 11-mm long-were placed in both types of bone (n = 60). The primary stability of all implants was measured by an experienced clinician blinded to the study protocol using the EPT and RFA devices. No statistically significant difference was found between the implant stability quotients and the percussive test values of straight and tapered implants in either bone type. Within the limitations of this ex vivo study, it may be concluded that the shape of an implant with a TCF design does not affect primary stability.

Measurement of Primary Stability of Mini Implants Using Resonance Frequency Analysis

Introduction In the last decade, anchorage control with mini-implants has gained enormous credibility in maintaining orthodontic anchorage. Resonance frequency analysis (RFA) has proven to be an adequate method to measure the stability of these mini-implants because of its non-invasiveness and contactless measurement method. Materials and Method Tomas and S.K surgical mini-implants were tested. For this purpose custom fabricated attachment was fabricated to attach the smart peg on orthodontic mini-implant head, and 45 mini-implants were inserted in fresh swine pelvic bone in the density matched sites to that of most common sites where mini-implants are placed in human mandible. Mini-implants of two different lengths with diameter constant were also placed to assess the effect of length on primary stability. Results The mean ISQ of Group 1 (Tomas 10 mm) was 55.53±3.39 while that of Group 2 (S.K Surgical 10mm) was 56.63±3.48 and that of Group 3(S.K Surgical 8 mm) was 55.90±3.48. Difference among the groups were not statistically significant when ANOVA test was used (P &gt;0.05). Conclusion The resonance frequency analysis is applicable to comparatively assess the primary stability of orthodontic mini-implants. There was no difference in primary stability of Tomas and S.K Surgical mini-implant and primary stability was not affected by the length of the mini-implant.

Characterization of Femoral Component Initial Stability and Cortical Strain in a Reduced Stem-Length Design

BackgroundShort-stemmed femoral components facilitate reduced exposure surgical techniques while preserving native bone. A clinically successful stem should ideally reduce risk for stress shielding while maintaining adequate primary stability for biological fixation. We asked (1) how stem-length changes cortical strain distribution in the proximal femur in a fit-and-fill geometry and (2) if short-stemmed components exhibit primary stability on par with clinically successful designs. MethodsCortical strain was assessed via digital image correlation in composite femurs implanted with long, medium, and short metaphyseal fit-and-fill stem designs in a single-leg stance loading model. Strain was compared to a loaded, unimplanted femur. Bone-implant micromotion was then compared with reduced lateral shoulder short stem and short tapered-wedge designs in cyclic axial and torsional testing. ResultsFemurs implanted with short-stemmed components exhibited cortical strain response most closely matching that of the intact femur model, theoretically reducing the potential for proximal stress shielding. In micromotion testing, no difference in primary stability was observed as a function of reduced stem length within the same component design. ConclusionOur findings demonstrate that within this fit-and-fill stem design, reduction in stem length improved proximal cortical strain distribution and maintained axial and torsional stability on par with other stem designs in a composite femur model. Short-stemmed implants may accommodate less invasive surgical techniques while facilitating more physiological femoral loading without sacrificing primary implant stability.

Evaluation of Primary Stability of Self‐Tapping and Non‐Self‐Tapping Dental Implants. A 12‐Week Clinical Study

The aim of this study was to investigate the relationship between surgical techniques and implant macro-design (self-tapping/non-self-tapping) for the optimization of implant stability in the low-density bone present in the posterior maxilla using resonance frequency analysis (RFA). A total of 102 implants were studied. Fifty-six self-tapping BlueSkyBredent® (Bredent GmbH&Co.Kg®, Senden, Germany) and 56 non-self-tapping Standard Plus Straumann® (Institut Straumann AG®, Waldenburg, Switzerland) were placed in the posterior segment of the maxilla. Implants of both types were placed in sites prepared with either lateral bone-condensing or with bone-drilling techniques. Implant stability measurements were performed using RFA immediately after implant placement and weekly during a 12-week follow-up period. Both types of implants placed after bone condensing achieved significantly higher stability immediately after surgery, as well as during the entire 12-week observation period compared with those placed following bone drilling. After bone condensation, there were no significant differences in primary stability or in implant stability after the first week between both implant types. From 2 to 12 postoperative weeks, significantly higher stability was shown by self-tapping implants. After bone drilling, self-tapping implants achieved significantly higher stability than non-self-tapping implants during the entire follow-up period. The outcomes of the present study indicate that bone drilling is not an effective technique for improving implant stability and, following this technique, the use of self-tapping implants is highly recommended. Implant stability optimization in the soft bone can be achieved by lateral bone-condensing technique, regardless of implant macro-design.

Piezoelectric vs. conventional implant site preparation: ex vivo implant primary stability

This study aims to determine differences in primary stability between implants placed in cortical bone following Piezoelectric or conventional site preparation, as assessed by resonance frequency analysis (RFA) and reverse torque testing (RTT). Four fresh bovine ribs were acquired and surgical guides fabricated with five sites per rib (n=20), for proper site preparation. Implant sites were prepared via conventional drilling technique as per manufacturer's instruction (Implantium) or via Piezoelectric (Mectron) implant site preparation using the Implant Prep kit. Twenty 10mm long, 3.6mm diameter Implantium implants were placed with 35Ncm torque; 10 implants per preparation method. RFA was assessed via the Osstell Mentor. Five values were taken per implant. All implants where subjected to a reverse torque in increasing increments of 5 until 50Ncm force was reached. The five RFA values per site were averaged and plotted by placement technique. A paired t-test statistical analysis was run. The average RFA values showed no statistical significance between the 10 test (RFA=69.04±5.11) and 10 control (RFA=70.94±6.41) sites (P>0.05). All implants in both groups withstood RTT up to 50Ncm force without movement and thus showed no statistical differences. Results of this ex vivo study imply that the Piezoelectric implant site preparation affords similar primary implant stability in comparison to conventional rotary instrumentation in cortical bone.

Self-cutting blades and their influence on primary stability of tapered dental implants in a simulated low-density bone model: a laboratory study

This study tested the hypothesis that there would be differences in primary stability due to the presence of self cutting blades. We investigated the effect of a self-cutting blade implant design on the primary stability of tapered dental implants in a simulated low-density bone model. Implant fixtures with 2 different designs, one with self-cutting blades and the other without self-cutting blades, were fabricated in the same implant system. Insertion torque, resonance frequency analysis, reverse torque, and pull-out and push-in tests were evaluated in grade no. 10 solid rigid polyurethane foam. All 5 assessments of the group without self-cutting blades were significantly higher than those of the self-cutting group (P < .001). The implants without self-cutting blades create a lateral compression with increased contact surface area and consequently improve the primary stability in a simulated low-density bone model.

Biomechanical Stability of Knotless Suture Anchors Used in Rotator Cuff Repair in Healthy and Osteopenic Bone

The primary stability of 5 new knotless suture anchors was compared in healthy and osteopenic humeri by use of the following anchor systems: Opus Magnum 2 (ArthroCare, Austin, TX), PushLock (Arthrex, Naples, FL), SwiveLock (Arthrex), Kinsa RC (Smith & Nephew, London, England), and Versalok (DePuy Mitek, Raynham, MA). Twenty healthy and 20 osteopenic, macroscopically intact humeri with mean ages of 47 and 72 years, respectively, and mean bone mineral densities of 139.8 mg of calcium hydroxyapatite (Ca2+-HA) per milliliter and 51.8 mg of calcium hydroxyapatite per milliliter, respectively, were used. Cyclic loading was performed to simulate postoperative conditions. The maximum failure load (F(max)), the system displacement, and the modes of failure were recorded. SwiveLock had the highest mean F(max) in healthy humeri, followed by Versalok, PushLock, Kinsa RC, and Opus Magnum 2, with SwiveLock and Versalok being statistically superior to Opus Magnum 2. In osteopenic humeri Versalok had the highest mean F(max), followed by Opus Magnum 2, SwiveLock, Kinsa RC, and PushLock, with no significant differences between all tested anchors. The Versalok anchor showed the shortest system displacement in healthy humeri, with 1.06 mm, and in osteopenic humeri, with 1.47 mm. In healthy humeri the system displacement of all anchors lay under the clinical failure threshold of 5 mm. In osteopenic humeri the PushLock clearly exceeded the clinical failure threshold, with 16.11 mm, whereas the other anchors were notably below the 5-mm threshold, with solitary measurements exceeding it. Every tested anchor presented different problems that may lead to premature failure of the rotator cuff reconstruction. Knotless suture anchors show differences in primary stability depending on the bone quality of the greater tuberosity, the anchorage mechanism in the bone, the suture-retaining mechanism, and the anchor design. Nevertheless, cortical screw type and subcortical wedging anchors tend to show better primary stability than other designs. Anchor design and bone quality play important roles in the stability of the rotator cuff repair.

Clinical study on the primary stability of two dental implant systems with resonance frequency analysis

Primary stability has a major impact on the long-term success of dental implants. The aim of this study was to investigate the correlation of resonance frequency analysis (RFA) and insertion torque of self-tapping and non-self-tapping implants and their respective differences in primary stability. A group of 263 patients were treated with a total of 602 conically formed dental implants: 408 non-self-tapping Ankylos and 194 self-tapping Camlog. The maximum insertion torque during implant placement was recorded. Resonance frequency, measured as the implant stability quotient (ISQ), was assessed once immediately after insertion and twice 3 months later. Torque values of the non-self-tapping implants were significantly higher than those in the self-tapping group (p = 0.023). RFA did not show differences between the 2 groups (p = 0.956), but a correlation between ISQ values after implantation and 3 months after implant placement was measured (r = 0.712). Within the implant systems, no correlation between insertion torque and resonance frequency values could be determined (r = 0.305). Our study indicates that the ISQ values obtained from different implant systems are not comparable. The RFA does not appear suitable for the evaluation of implant stability when used as a single method. Higher insertion torque of the non-self-tapping implants appeared to confirm higher clinical primary stability.

Primary Stability of Osteochondral Grafts Used in Mosaicplasty

The goal of our experiments was to determine the primary stability of osteochondral grafts used in mosaicplasty. The effect of graft diameter and dilation, as well as multiple grafting, were studied in a porcine model. Single osteochondral grafts, 4.5 and 6.5 mm in diameter, and multiple grafts were transplanted from the trochlea of porcine femurs to the weight-bearing area of the lateral femoral condyle. In the multiple grafting series, 3 grafts 4.5 mm in diameter were transplanted either in a row or in circular fashion. The grafts were first pushed in level with the surrounding cartilage surface, then they were pushed 3 mm below cartilage level. The push-in forces were measured. The effect of graft diameter and the extent of dilation on primary stability were studied as well as the influence of multiple grafting. In the case of 4.5-mm grafts, the mean level push-in force was 43.5 N, and pushing 3 mm below cartilage level required a mean of 92.5 N (n = 13). In the case of 6.5-mm grafts, level push-in required a mean of 76.2 N, and for pushing 3 mm below cartilage level a mean of 122.2 N force had to be used (n = 14). The length of the drill hole and the dilation were both 20 mm in each setting. When using 20-mm long drill holes and 15-mm dilation length, the values above were found to be 36.6 N and 122.5 N in the case of 4.5-mm grafts (n = 12). Mean level push-in force in the first (row) multiple series was 31.8 N, and pushing 3 mm below cartilage level required a mean of 52.17 N (n = 7). In the second series (circle), level push-in required a mean of 30.44 N, and for pushing 3-mm below cartilage level a mean of 54.33 N force had to be used (n = 9). In the control series (1 single graft) the mean level push-in force was 38.7 N, and pushing 3 mm deeper required a mean of 86.8 N (n = 9). These results suggest that grafts of greater diameter are more stable in absolute values and stability may be increased by shorter dilation length, whereas level push-in forces do not increase significantly. There is no difference in primary stability between grafts implanted in a row or in circular fashion, and multiple grafts may not be as stable as single grafts in the initial period after transplantation. This is a randomized, controlled in vitro animal trial that helps us to better understand the primary stability of osteochondral grafts and to refine surgical techniques as well as postoperative protocols.