scholarly journals Two Different Methods to Measure the Stability of Acetabular Implants: A Comparison Using Artificial Acetabular Models

Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 254
Author(s):  
Quentin Goossens ◽  
Leonard Cezar Pastrav ◽  
Michiel Mulier ◽  
Wim Desmet ◽  
Jos Vander Sloten ◽  
...  

The total number of total hip arthroplasties is increasing every year, and approximately 10% of these surgeries are revisions. New implant design and surgical techniques are evolving quickly and demand accurate preclinical evaluation. The initial stability of cementless implants is one of the main concerns of these preclinical evaluations. A broad range of initial stability test methods is currently used, which can be categorized into two main groups: Load-to-failure tests and relative micromotion measurements. Measuring relative micromotion between implant and bone is recognized as the golden standard for implant stability testing as this micromotion is directly linked to the long-term fixation of cementless implants. However, specific custom-made set-ups are required to measure this micromotion, with the result that numerous studies opt to perform more straightforward load-to-failure tests. A custom-made micromotion test set-up for artificial acetabular bone models was developed and used to compare load-to-failure (implant push-out test) with micromotion and to assess the influence of bone material properties and press-fit on the implant stability. The results showed a high degree of correlation between micromotion and load-to-failure stability metrics, which indicates that load-to-failure stability tests can be an appropriate estimator of the primary stability of acetabular implants. Nevertheless, micromotions still apply as the golden standard and are preferred when high accuracy is necessary. Higher bone density resulted in an increase in implant stability. An increase of press-fit from 0.7 mm to 1.2 mm did not significantly increase implant stability.

2021 ◽  
Vol 11 (12) ◽  
pp. 5612
Author(s):  
Stefano Fanali ◽  
Margherita Tumedei ◽  
Pamela Pignatelli ◽  
Alessandra Lucchese ◽  
Francesco Inchingolo ◽  
...  

Background: Implant primary stability can be affected by several factors related to implant macrogeometry, local anatomy, and surgical techniques. The aim of this research was to study primary stability on polyurethane foam sheets of wide-threaded implant design compared to narrow-threaded implants. Materials and methods: Two different implant designs were positioned on D3 density polyurethane blocks in a standardized environment: the wide-threaded implant and the narrow-threaded implant, for a total of 160 specimens. Moreover, for each group, two different sizes were considered: 3.8mm × 12mm and 4.8mm × 12 mm. The insertion torque (IT) values, the removal strength (RT), and the Periotest analyses were evaluated. Results: A significantly higher IT and RT was reported for wide-threaded implants and two-stage implants (p < 0.01), compared to the narrow-threaded implants. The diameters seemed to provide a significant effect on the primary stability for both implants’ geometry (p < 0.01). A higher mean of the one-stage implant was evident in the Periotest measurements (p < 0.01). Conclusions: Both of the implants showed sufficient stability in polyurethane artificial simulation, while the wide-threaded implant design showed a higher primary stability on alveolar cancellous synthetic bone in vitro. Additionally, the prosthetic joint connection seemed to have a determinant effect on Periotest analysis, and the one-stage implants seemed to provide a high stability of the fixture when positioned in the osteotomy, which could be important for the immediate loading protocol.


2013 ◽  
Vol 70 (6) ◽  
pp. 586-594 ◽  
Author(s):  
Zoran Vlahovic ◽  
Branko Mihailovic ◽  
Zoran Lazic ◽  
Mileta Golubovic

Background/Aim. Flapless implant surgery has become very important issue during recent years, mostly thanks to computerization of dentistry and software planning of dental implants placements. The aim of this study was to compare flap and flapless surgical techniques for implant placement through radiographic and radiofrequency analyses. Methods. The experiment was made in five domestic pigs. Nine weeks following domestic pigs teeth extraction, implants were placed, on the right side using surgical technique flap, and flapless on the left side. Digital dental Xrays were applied to determine primary dental implant stability quality (ISQ). At certain intervals, not later than three months, the experimental animals were sacrificed, and just before it, control X-rays were applied to measure dental implants stability. Results. Radiographic analysis showed that peri-implant bone resorption in the first 4 weeks following placement implants with flap and flapless surgical techniques was negligible. After the 3 months, mean value of peri-implant bone resorption of the implants placed using flap technique was 1.86 mm, and of those placed using flapless technique was 1.13 mm. In relation to the primary dental implant stability in the first and second week there was an expected decrease in ISQ values, but it was less expressed in the dental implants placed using the flapless technique. In the third week the ISQ values were increased in the dental implants placed by using both techniques, but the increase in flapless implant placement was higher (7.4 ISQ) than in flap implant placement (1.5 ISQ). The upward trend continued in a 4- week period, and after 3 months the dental implant stability values in the implants placed using flap technique were higher than the primary stability for 7.1 ISQ, and in the implants placed using flapless technique were higher comparing to the primary stability for 10.1 ISQ units. Conclusion. Based on the results of radiographic and resonance frequency analyses it can be concluded that the flapless technique in surgical implants placemat, leads to better results.


2019 ◽  
Vol 45 (4) ◽  
pp. 259-266
Author(s):  
Claudio Stacchi ◽  
Matteo De Biasi ◽  
Lucio Torelli ◽  
Massimo Robiony ◽  
Roberto Di Lenarda ◽  
...  

The primary objective of the present in vitro study was to evaluate the influence of implant site preparation technique (drills vs ultrasonic instrumentation) on the primary stability of short dental implants with two different designs inserted in simulated low-quality cancellous bone. Eighty implant sites were prepared in custom-made solid rigid polyurethane blocks with two different low cancellous bone densities (5 or 15 pounds per cubic foot [PCF]), equally distributed between piezoelectric (Surgysonic Moto, Esacrom, Italy) and conventional drilling techniques. Two short implant systems (Prama and Syra, Sweden & Martina) were tested by inserting 40 fixtures of each system (both 6.0 mm length and 5.0 mm diameter), divided in the four subgroups (drills/5 PCF density; drills/15 PCF density; piezo/5 PCF density; piezo/15 PCF density). Insertion torque (Ncm), implant stability quotient values, removal torque (Ncm), and surgical time were recorded. Data were analyzed by 3-way ANOVA and Scheffé's test (α = 0.05). With slight variations among the considered dependent variables, overall high primary implant stability was observed across all subgroups. Piezoelectric instrumentation allowed for comparable or slightly superior primary stability in comparison with the drilling procedures in both implant systems. The Prama implants group showed the highest mean reverse torque and Syra implants the highest implant stability quotient values. Piezoelectric implant site preparation took prolonged operative time compared to conventional preparation with drills; among the drilling procedures, Syra system required fewer surgical steps and shorter operative time.


2017 ◽  
Vol 43 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Yen-Ting Lin ◽  
Adrienne Hong ◽  
Ying-Chin Peng ◽  
Hsiang-Hsi Hong

Clinical decisions regarding the stability and osseointegration of mandibular implants positioned using the bone expansion techniques are conflicting and limited. The objective was to evaluate the stability of implants placed using 2 surgical techniques, selected according to the initial width of the mandibular posterior edentulous ridge, with D3 bone density, during a 12-week period. Fifty-eight implants in 33 patients were evaluated. Thirty-two implants in 24 patients were positioned using the osteotome expansion technique, and 26 fixtures in 17 patients were installed using the conventional drilling technique. The implant stability quotient values were recorded at weeks 0, 1, 2, 3, 4, 6, 8, 10, and 12 postsurgery and evaluated using analysis of variance, independent, and paired t tests. Calibrated according to the stability reading of a 3.3-mm diameter implant, the osteotome expansion group was associated with a lower bone density than the conventional group (64.96 ± 6.25 vs 68.98 ± 5.06, P = .011). The osteotome expansion group achieved a comparable primary stability (ISQb-0, P = .124) and greater increases in secondary stability (ISQb-12, P = .07) than did the conventional technique. A D3 quality ridge with mild horizontal deficiency is expandable by using the osteotome expansion technique. Although the 2 groups presented similar implant stability quotient readings during the study period, the osteotome expansion technique showed significant improvement in secondary stability. The healing patterns for these techniques are therefore inconsistent.


2019 ◽  
Vol 2019 ◽  
pp. 1-4 ◽  
Author(s):  
Antonio Scarano ◽  
Bartolomeo Assenza ◽  
Francesco Inchingolo ◽  
Filiberto Mastrangelo ◽  
Felice Lorusso

Background. The immediate placement of a dental implant could represent an option treatment for the rehabilitation of a postextractive missing tooth socket to replace compromised or untreatable teeth, with the advantage of single-session surgery. In this way, the anatomy of the alveolar bone defect, the preservation of the buccal cortical bone, and the primary stability of the fixture represent the critical factors that consent a precise implant placement. Objective. This case report describes a novel fixture design for postextractive alveolar socket immediate implant. Methods. Two patients (25 and 31 years old) were treated for postextractive dental implant placement to replace both central upper incisor teeth with four implants. The residual bone implant gap was not filled with graft or bone substitute. The restoration was provided following a standard loading protocol by a cement-sealed prosthetic abutment. Results. Clinically, all implants positioned showed an excellent insertion torque. No postoperative complications were reported. At 6 months of healing, the buccal cortical bone and the implant stability were present and well maintained. Conclusion. The evidence of this study allows us to underline the possible advantages of this new fixture design for postextractive implant technique.


2009 ◽  
Vol 35 (3) ◽  
pp. 130-135 ◽  
Author(s):  
Linus Chong ◽  
Ahmed Khocht ◽  
Jon B. Suzuki ◽  
John Gaughan

Abstract Implant design is one of the parameters for achieving successful primary stability. This study aims to examine the effect of a self-tapping blades implant design on initial stability in tapered implants. Polyurethane blocks of different densities were used to simulate different bone densities. The two different implant designs included one with self-tapping blades and one without self-tapping blades. Implants were placed at 3 different depths: apical third, middle third, and fully inserted at 3 different densities of polyurethane blocks. A resonance frequency (RF) analyzer was then used to measure stability of the implants. Repeated-measures analysis of variance was used to examine the effect of implant design, insertion depth, and block density on RF. Analysis of covariance was used to examine the strength of association between RF and the aforementioned factors. In both medium-density (P = .017) and high-density (P = .002) blocks, fully inserted non-self-tapping implants showed higher initial stability than self-tapping implants. No differences were noted between the 2 implant designs that were not fully inserted. The highest strength of association was with insertion depth (standardized beta [std β] = −0.60, P = .0001), followed by block density (std β = −0.15, P = .0002). Implant design showed a weak association (std β = −0.07, P = .09). In conclusion, fully inserted implants without self-tapping blades have higher initial stability than implants with self-tapping blades. However, the association strength between implant design and initial stability is less relevant than other factors, such as insertion depth and block density. Thus, if bone quality and quantity are optimal, they may compensate for design inadequacy.


Author(s):  
I. Udofia ◽  
F. Liu ◽  
Z. Jin ◽  
P. Roberts ◽  
P. Grigoris

To ensure potential long-term stability and survivorship for metal-on-metal hip resurfacing prostheses, implant migration would need to be minimised to encourage bone in-growth. This study uses the finite element method to investigate the effects of the surgical press-fit procedure on the bearing and interfacial contact mechanics, and on the initial stability of a metal-on-metal (MOM) hip resurfacing prosthesis. The finite element models simulated the press-fit procedure using different amounts of interference between the cup-bone (1–2mm). The resurfacing prosthesis was implanted anatomically into a 3-D bone model. Resultant hip joint loads were applied to the model through muscle and subtrochanteric forces. Results showed that increasing the friction and the interference between the cup and bone resulted in significant reductions in the relative micromotion between the cup and bone. This would ensure the immediate post-operative stability of the acetabular cup and provide adequate conditions for potential long-term bone in-growth and implant stability. The contact mechanics at the bearing surfaces, which has a large effect on tribological performance, was found to be little affected by changes at the cup-bone interface. These findings are consistent with the general satisfactory short and medium-term clinical results of metal-on-metal hip resurfacing prostheses. This study suggests that interference, friction and a mechanically sound bone structure are important parameters to promote implant stability and support.


2015 ◽  
Vol 41 (6) ◽  
pp. e281-e286 ◽  
Author(s):  
Sergio Alexandre Gehrke ◽  
Ulisses Tavares da Silva ◽  
Massimo Del Fabbro

The purpose of this study was to assess implant stability in relation to implant design (conical vs. semiconical and wide-pitch vs narrow-pitch) using resonance frequency analysis. Twenty patients with bilateral edentulous maxillary premolar region were selected. In one hemiarch, conical implants with wide pitch (group 1) were installed; in the other hemiarch, semiconical implants with narrow pitch were installed (group 2). The implant allocation was randomized. The implant stability quotient (ISQ) was measured by resonance frequency analysis immediately following implant placement to assess primary stability (time 1) and at 90 days after placement (time 2). In group 1, the mean and standard deviation ISQ for time 1 was 65.8 ± 6.22 (95% confidence interval [CI], 55 to 80), and for time 2, it was 68.0 ± 5.52 (95% CI, 57 to 77). In group 2, the mean and standard deviation ISQ was 63.6 ± 5.95 (95% CI, 52 to 78) for time 1 and 67.0 ± 5.71 (95% CI, 58 to 78) for time 2. The statistical analysis demonstrated significant difference in the ISQ values between groups at time 1 (P = .007) and no statistical difference at time 2 (P = .54). The greater primary stability of conical implants with wide pitch compared with semiconical implants with narrow pitch might suggest a preference for the former in case of the adoption of immediate or early loading protocols.


2020 ◽  
Vol 15 (2) ◽  
Author(s):  
Kambiz Behzadi ◽  
Jesse Rusk

Abstract Total hip replacement is a widespread medical procedure, with over 300,000 surgeries performed each year in the United States alone. The vast majority of total hip replacements utilize press fit fixation. Successful seating of the implant requires a delicate balance between inserting the implant deep enough to obtain sufficient primary stability, while avoiding fracture of bone. To improve patient outcomes, surgeons need assistive technologies that can guide them as to how much force to apply and when to stop impacting. The development of such technology, however, requires a greater understanding of the forces experienced in bone and the resulting cup insertion and implant stability. Here, we present a preliminary study of acetabular cup insertion into bone proxy samples. We find that as the magnitude of force on the acetabular cup increases, cup insertion and axial extraction force increase linearly, then nonlinearly, and finally plateau with full insertion. Within the small nonlinear zone, approximately 90% of both cup insertion and extraction force are achieved with only 50% total energy required for full seating, posing the question as to whether full seating is an appropriate goal in press-fit arthroplasty. For repeated impacts of a given energy, cup displacement and force experienced in bone (measured force profile—MFP) increase correspondingly and reach a plateau over a certain number of impacts (number of impacts to seating—NOITS), which represents the rate of insertion. The relationship between MFP and NOITS can be exploited to develop a force feedback mechanism to quantitatively infer optimal primary implant stability.


2017 ◽  
Vol 43 (3) ◽  
pp. 186-193 ◽  
Author(s):  
Rosa-María Díaz-Sánchez ◽  
José-María Delgado-Muñoz ◽  
Pilar Hita-Iglesias ◽  
Kyle T. Pullen ◽  
María-Ángeles Serrera-Figallo ◽  
...  

To ensure similar primary implant stability measured by resonance frequency analysis (RFA) could be obtained in different jawbone densities by using a specific surgical drilling protocol and, to correlate those RFA measurements with factors related to the implant design, width, and length, we are performed a 1-year prospective clinical study was carried out using 27 subjects. A total of 67 hydrophilic titanium implants were placed using a standard 2-stage implant placement protocol. The bone type at each implant site was determined by evaluation of a preoperative, high-resolution cone beam computerized tomography (CBCT) scan. A modified drilling protocol was used in softer bone (types 2, 3, and 4) that allowed for greater implant thread contact with the surrounding bone. The implant stability quotient (ISQ) was measured at 4 different times during the study: initially it was determined immediately after implant placement, then again at stage 2 uncovering surgery, then at 6 months' postplacement and, and finally at 1 year postplacement. Data collected immediately after implant surgery demonstrated a high correlation (R2 = .99) between the ISQ and bone type classification. An overall trend toward a higher ISQ was found over the 1-year study period for all types of bone. Implants remained clinically and radiographically stable during the 1-year study period. Our data allow conclude that the primary stability of 2-staged loaded implants placed in different bone types can be optimized by applying this surgical drilling protocol during the implant placement. The ISQ method was found to be a reliable predictor of implant stability.


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