Stability Of Implants Research Articles

An analytical model to measure dental implant stability with the Advanced System for Implant Stability Testing (ASIST)

A non-invasive method of quantitatively assessing dental implant stability is important to monitor its long-term health. The Advanced System for Implant Stability Testing (ASIST) is a noninvasive technique that couples the impact technique with a linear vibration model of the implant system, such that the measured signal can be used to determine a matching analytical response. The purpose of this study was to evaluate the ASIST technique by comparing stability estimates obtained from artificial implant installations with various abutments. Two Straumann dental implants were installed in four densities of uniform polyurethane foam, and the stability of each installation was measured using different healing abutments and artificial dental crowns. With the ASIST, values for the estimated interfacial stiffness increased with foam density and did not significantly change with abutment type for a specific sample. This provides evidence that the analytical model is representative of the physical system. Current methods, such as resonance frequency analysis, interpret the interface stiffness based on a single frequency measurement. With the ASIST, the measured signal provides information about the first and second modes of vibration of the implant system, both of which are influenced by the properties of the corresponding abutment. The consideration of both modes allows the technique to reliably measure the interfacial stiffness independently of the system components. As a result, the ASIST technique may provide an improved non-invasive method of measuring the stability of dental implants.

Implant Stability in Regenerated Bone

Bone regeneration is a surgical therapy that is increasingly being used for implant placement in functional patient rehabilitation [...]

ε-Poly-l-lysine-hydroxyphenyl propionic acid/IL-4 composite hydrogels with inflammation regulation and antibacterial activity for improving integration stability of soft tissues and orthopedic implants

The failure of orthopedic implants is usually caused by inflammation, poor tissue integration, and infection, which can lead to pain, limited mobility, dysfunction of patients. This may require additional surgical interventions, such as removal, replacement, or repair of implants, as well as related treatment measures such as antibiotic therapy, physical therapy. Here, an injectable hydrogel carrier was developed for the steady release of inflammatory regulators to reduce the surface tissue inflammatory response of orthopedic implants and induce soft tissue regeneration, ultimately achieving the promotion of implants stability. The hydrogels carrier was prepared by hydroxyphenyl propionic acid-modified ε-Poly-l-lysine (EPA), hydrogen peroxide and horseradish peroxidase, which showed antibacterial bioactive and stable factor release ability. Due to the introduction of IL-4, EPA@IL-4 hydrogels showed good inflammatory regulation. EPA@IL-4 hydrogels regulated the differentiation of macrophages into M2 in inflammatory environment in vitro, and promoted endothelial cells to show a more obvious trend of tube formation. The composite hydrogels reduced the inflammation on the surface of the implants in vivo, induced local endothelial cell angiogenesis, and had more collagen deposition and new granulation tissue. Therefore, EPA hydrogels based on IL-4 release are promising candidates for promoting of implants surface anti-inflammatory, soft tissue regeneration, and anti-infection.

Biomechanical evaluation of three implants for treating unstable femoral intertrochanteric fractures: finite element analysis in axial, bending and torsion loads.

Purpose: How to effectively enhance the mechanical stability of intramedullary implants for unstable femoral intertrochanteric fractures (UFIFs) is challenging. The authors developed a new implant for managing such patients. Our aim was to enhance the whole mechanical stability of internal devices through increasing antirotation and medial support. We expected to reduce stress concentration in implants. Each implant was compared to proximal femoral nail antirotation (PFNA) via finite element method. Methods: Adult AO/OTA 31-A2.3 fracture models were constructed, and then the new intramedullary system (NIS), PFNA, InterTan nail models were assembled. We simulated three different kinds of load cases, including axial, bending, and torsion loads. For further comparison of PFNA and the NIS, finite element analysis (FEA) was repeated for five times under axial loads of 2100N. Two types of displacement and stress distribution were assessed. Results: Findings showed that the NIS had the best mechanical stability under axial, bending, and torsion load conditions compared to PFNA and InterTan. It could be seen that the NIS displayed the best properties with respect to maximal displacement while PFNA showed the worst properties for the same parameter in axial loads of 2100N. In terms of maximal stress, also the NIS exhibited the best properties while PFNA showed the worst properties in axial loads of 2100N. For bending and torsion load cases, it displayed a similar trend with that of axial loads. Moreover, under axial loads of 2100N, the difference between the PFNA group and the NIS group was statistically significant (p < 0.05). Conclusion: The new intramedullary system exhibited more uniform stress distribution and better biomechanical properties compared to the PFNA and InterTan. This might provide a new and efficacious device for managing unstable femoral intertrochanteric fractures.

Effects of Piezoelectric Surgery on Implant Stability and Marginal Bone Level: Systematic Review and Meta-analysis

Effects of Piezoelectric Surgery on Implant Stability and Marginal Bone Level: Systematic Review and Meta-analysis

Polypyrrole zinc-doped film deposited on a plasma-treated surface improves the tribocorrosion behavior of titanium dental implant material

Polypyrrole (PPy) films have shown attractive electrochemical properties and promising implant applications when electrodeposited on plasma electrolytic oxidation (PEO) surfaces. Although the PEO + PPy surface demonstrates excellent mechanical and electrochemical performance, there are no reports on the effects of combined corrosion and mechanical interactions, which simulates the oral environment. In addition, since implant failures may be related to deficiencies in the osseointegration process, the electrodeposition of zinc (Zn) on the coating can promote an osteogenic substrate. Therefore, we aimed to investigate the tribocorrosion behavior of PEO-treated surfaces coated with PPy films with and without Zn and whether such PPy films affect the cellular response of MG-63 human osteoblast-like cells. Titanium discs with machined and PEO-modified surfaces were considered as controls. The experimental groups used PEO surfaces followed by electrodeposition of PPy (PEO + PPy) and PPy and Zn (PEO + PPy/Zn). The surfaces' physical-chemical properties were assessed. The tribocorrosion tests were run under free potential and potentiostatic (anodic and cathodic potentials) conditions using a pin-on-disk tribosystem simulating the oral environment (load = 1 N, stroke = 2 mm, number of cycles = 2000). Electrochemical impedance spectroscopy was performed before and after tribocorrosion to analyze the changes in corrosion kinetics. Worn areas were observed using white-light-interferometry and scanning electron microscopy. For in vitro cell experiments, the viability, number of live/dead cells, adhesion ability, and mineralization property of cells were evaluated. Our outcomes revealed that PPy films improved tribocorrosion performance by exhibiting more positive OCP values and slight fluctuation and variation of the current value during the sliding phases. In general, due to the films' morphology and “cushion effect”, PPy films enhanced the surface resistance against corrosion and wear, indicating a low total weight loss (Kwc) and wear-corrosion degradation mechanism. The PEO + PPy/Zn surface was cytocompatible, enhancing the cell adhesion and proliferation on the surface. Overall, PPy films represent a promising coating to improve the stability and lifetime of biomedical implants.

Dental rehabilitation in irradiated oral cancer patients using patient-specific dental implants – Clinical outcome and oral health-related quality of life

IntroductionDental rehabilitation in oral cancer patients is essential for good oral health-related quality of life (OHRQoL). Patient-specific dental implants are suitable for treating tumor-related bony defects, resulting in satisfactory OHRQoL. However, knowledge concerning the clinical outcome and OHRQoL following tumor irradiation is lacking. Material and MethodsA retrospective analysis was carried out to evaluate clinical outcomes and OHRQoL in eight patients who received patient-specific dental implants and implant-supported dentures after surgical treatment for oral cancer with additional irradiation. OHRQoL assessment was performed using the German long version of the oral health impact profile (OHIP) questionnaire (OHIP-G53). ResultsClinical examination revealed successful dental rehabilitation in all the patients with only minor impairments. Restricted stability and function of implants were not observed. OHIP sum-scores of all the patients indicated acceptable OHRQoL, but this varied between patients treated in the upper or lower jaw. Single-item sum-scores concerning the adverse events “difficulty in chewing,” “food catching,” “sore jaw,” “sore spots,” and “unclear speech” were detected to be the worst, and pain-related OHIP dimensions demonstrated the highest scores (followed by functional limitation, physical disability, and psychosocial impact) with a worse OHRQoL following lower jaw treatment. Other dimension sum-scores were overall lower and nearly equally distributed in patients. ConclusionsDental rehabilitation of irradiated oral cancer patients using patient-specific dental implants may be suitable, leading to acceptable OHRQoL. However, implant insertion in the upper jaw seems to be more favorable. Further studies on patient-specific dental implants are warranted to validate the current results.

Optimizing Osseointegration in Dental Implantology: A Cross-Disciplinary Review of Current and Emerging Strategies.

The paper explores the correlation between osteointegration and dental implant stability, investigating the relationship and its implications for successful outcomes in implant dentistry. Osteointegration, defined as the direct structural and functional connection between living bone and the implant surface, plays a crucial role in determining the stability and long-term success of dental implants. This review synthesizes current knowledge from scientific literature and clinical studies to elucidate the factors influencing osteointegration and their impact on implant stability. Surface characteristics of implants, such as topography and chemistry, as well as the surgical techniques employed during implant placement, are examined in detail, emphasizing their significant influence on osseointegration and subsequent implant stability. Additionally, host-related factors such as bone quality, systemic conditions, and patient-specific considerations are explored to further comprehend the complexity of the osteointegration process. The abstract underscores the importance of achieving an optimal bone-implant interface to ensure successful implant integration and stability. Furthermore, emerging technologies and materials, such as computer-guided implant placement and biomimetic surfaces, are discussed for their potential to enhance osteointegration and improve long-term implants.

Effect of Dynamic Cycles and Abutment Angle on The Screw Stability of Standard and Narrow Implants: An In vitro Study

Objective: Screw loosening in implant-supported crowns is a common issue, leading to potential mechanical and biological complications. This study aimed to evaluate the combined influence of cyclic loading, abutment angulation, and implant diameter on screw torque loss in dental implants. Material and Methods: A total of 80 bone-level implants, divided into standard and narrow diameters, underwent cyclic loading protocols. These implants were paired with straight and 15-degree angled abutments. The study assessed the reverse torque values (RTV) before and after loading, with a primary focus on the effects of cyclic loading, abutment angulation, and implant diameter on screw torque loss. Results: Cyclic loading protocols and screw diameter significantly influenced screw torque loss. Standard diameter implants exhibited higher RTV compared to narrow diameter implants. . While the role of abutment angulation was less definitive, narrow diameter implants with angled placements showed a pronounced decrease in RTV. The study also highlighted that even with optimal preload values, a percentage of the initial preload is lost, potentially leading to screw loosening Conclusion: Cyclic loading and screw diameter are pivotal determinants of screw torque loss in dental implants. The study underscores the need for careful consideration of implant diameter and abutment angulation, especially in narrow diameter implants with angled abutments, to ensure optimal implant stability.

A Novel Screwless Modification of the Khoury Plate Technique using an Innovative Bone Adhesive Formulated from Underwater Biomimetic Marine Proteins.

The Khoury plate technique has been widely utilized with much success over the past 2 decades to facilitate bone augmentations in critically deficient bone areas. Simply, the technique encompasses harvesting autogenous bone plates and utilizing them with external screw fixation. The rigidity of the bone plates enclosing the bony defect on both the buccal and lingual surfaces allows for tension free bone remodeling to occur favoring an ideal bone forming environment. Following, a 4-6 month healing period, a flap is raised, screws may be removed and implant placement then follows. With advancements made in tissue engineering, recently a novel mineral-organic resorbable bone adhesive (MORBA) formulated from underwater biomimetic marine proteins has been utilized for immediate fixation of either bone-to-bone or bone-to-metal. MORBA is a synthetic, injectable, self-setting, and resorbable load-bearing adhesive biomaterial that exhibits over 300 pounds of fixation strength. The unique adhesive properties of MORBA enable it to provide immediate stabilization of dental implants into host bone. The present article describes a novel modification of the Khoury plate technique by utilizing MORBA as a substitute for screws during the fixation of bone plates. A step by step protocol is described where this novel biomaterial was utilized as a substitute to screws favoring a more biological approach to this conventional technique. This novel modification is both surgically easier to conduct, and favors a more biocompatible option that avoids screw fixation and removal.

The mechanical and clinical influences of prosthetic index structure in Morse taper implant-abutment connection: a scoping review

AimThe implant-abutment connection is a crucial factor in determining the long-term stability of dental implants. The use of a prosthetic index structure in the Morse taper implant-abutment connection has been proposed as a potential solution to improve the accuracy of this connection. This study aimed to provide a scoping review of the mechanical and clinical effects of the prosthetic index structure in the Morse taper implant-abutment connection.MethodsA systematic scoping review of articles related to "dental implants," "Morse taper," and "index" was conducted using PubMed/MEDLINE, Web of Science, Cochrane, and Scopus databases, as well as a comprehensive literature search by two independent reviewers. Relevant articles were selected for analysis and discussion, with a specific focus on investigating the impact of prosthetic index structure on the mechanical and clinical aspects of Morse taper implant-abutment connections.ResultsFinally, a total of 16 articles that met the inclusion criteria were included for data extraction and review. In vitro studies have demonstrated that the use of a prosthetic index structure in the Morse taper implant-abutment connection can affect stress distribution, biomechanical stability, and reverse torque values, which may reduce stress within cancellous bone and help limit crestal bone resorption. However, retrospective clinical studies have shown that this structure is also associated with a higher risk of mechanical complications, such as abutment fracture and abutment screw loosening.ConclusionsTherefore, the clinical trade-off between preventing crestal bone resorption and mechanical complications must be carefully considered when selecting appropriate abutments. The findings suggest that this structure can improve the accuracy and stability of the implant-abutment connection, but its use should be carefully evaluated in clinical practice.

Diabetes-related Screw Loosening: The Distinction of Surgical Sites and the Relationship among Diabetes, Implant Stabilization and Clinical Outcomes.

Diabetes mellitus (DM) is correlated with poor clinical outcomes in spinal surgery. However, the effect of it on screw stabilization has not been investigated. The aim of this study was to evaluate the screw loosening rate and postoperative outcomes in diabetic patients and to identify potential risk factors associated with loosening. This was a retrospective study. Two hundred and forty-three patients who received cervical or lumbar internal fixation between 2015 and 2019 were enrolled. Screw loosening was assessed on radiography, and clinical outcomes were evaluated by the improvement of visual analogue scale (VAS), Oswestry disability index (ODI) or Japanese Orthopaedic Association (JOA) scores. The relationship of DM, screw loosening and clinical outcomes were analyzed with chi-square tests and regression analyses. One hundred and twenty-two patients (50.2%) with diabetes were included in this study. Diabetes led to the increase of the rate of screw loosening in the lumbar spine, while the loosening rate did not vary significantly in the cervical spine. The occurrence of screw loosening in the lumbar spine was more likely to be associated with clinical outcomes for motor performance including walking and sitting. However, no significant effect on JOA and VAS scores in the cervical spine of screw loosening was found. Moreover, the history of DM affected the outcomes of the patients who underwent spinal surgery. DM had an adverse effect on screw stabilization. The impaired improvement of clinical outcomes in diabetics after spinal surgery was related to screw loosening. In addition to the direct effects on operative wounds and neural function, the impact on the screws due to DM was also worth noting.

The Orthodontic Mini-Implants Failures Based on Patient Outcomes: Systematic Review.

Anchorage is a challenge and essential issue for an orthodontist in determining the success of orthodontic treatment. Orthodontic anchorage is defined as resistance to unwanted tooth movement. Mini-implant is one of the devices that can be used as an anchor in orthodontic treatment. Many cases have reported successful treatment using mini-implant, but there are cases where mini-implants may fail. Failure of mini-implants can affect orthodontic treatment, and it is known that several factors may lead to mini-implant loss in orthodontic treatment. This systematic review aimed to determine the factors influencing mini-implant failure in orthodontic treatment. Articles were selected from electronic databases (PubMed, Google Scholar, The Cochrane Library, ScienceDirect) from January 2015 until 2023 according to the PRISMA method (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) under the PEOS (Population-Exposure-Outcome-StudyType) framework questions for systematic review. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42022337684). All data collected were in English, and filtering was done by eliminating duplicate data, meta-analysis, case reports, case series, mini-reviews, and animal studies. The analysis was further divided into three groups, that is, patient-related, implant-related, and operator-related and operator-related (A graphical abstract provided as a Supplementary information [available in the online version]). Twenty-one articles were identified according to the inclusion criteria in the form of retrospective, prospective, in vivo, and randomized controlled trial studies. Mini-implant failures due to patient-related showed six etiological factors, failures due to implant-related had eight etiological factors, and only one factor was operator-related, which may lead to mini-implant failure. The data was extracted without a computerized system and only in English. Mini-implant failure can be caused by many factors; we could not accuse one major factor as a cause. However, the quality or condition of the bones and oral hygiene are factors that play a significant role in obtaining the stability of implants. Mini-implant failure is highly influenced by poor oral hygiene and peri-implant inflammation. Comprehensive diagnostic prior to mini-implant insertion should be appropriately considered. This systematic review describes several factors that can influence mini-implant failure, divided into three groups: patient-related, implant-related, and operator-related (A graphical abstract provided as a Supplementary information [available in the online version]).

Evaluation of osseointegration by resonance frequency analysis in patients with different bone mineral density: clinical and biomechanical aspects

The method of resonance frequency analysis was used to compare the stability of dental implants in patients with normal bone tissue condition, osteopenia and osteoporosis. The indicators allow obtaining information on the state of the implants and determining the permissible biomechanical load using an orthopedic structure. The measurement method allows observing the dynamics of the osteointegration process, and, if necessary, make timely adjustments to the functional load.Material and methods: comprehensive examination and treatment of 690 patients who applied to the clinic for dental flaw removal by dental implantation. Among them, 547 were (79.3%) women and 143 (20.7%) men. In preparation for dental implantation operations, all patients, except for the standard examination, were also densitometrically examined by double X-ray photon absorptiometry, which revealed systemic changes in bone mineral density. Stability of dental implants and osteointegration were monitored by resonance frequency analysis.Results: the overall value of the resonance-frequency analysis, regardless of the region of implants installed in patients with normal bone tissue, differed from those of the osteopenia and osteoporosis group, and was respectively higher by 7.1% (p &lt; 0.001) and 10.1% (p &lt; 0.001). The overall rate in the osteopenia group was higher, and differed from such a group of patients with osteoporosis by 5.7% (p &lt; 0.001).Conclusion: the results of the resonance-frequency analysis provide significant information about the state of the implant-bone interface at different stages of treatment and at control examinations of patients. The measurement method allows observing the dynamics of the osteointegration process, and, if necessary, make timely adjustments to the functional load. Resonance frequency analysis is an important method for documenting the clinical outcome of implantation.

Recombinant Human Bone Morphogenetic Protein-2 as Bone Additive and its Relation with the Dental Implant Dimensions and Stability: Split-Mouth Randomized Clinical Trial

Background: The bone morphogenetic protein belongs to transforming growth factor beta (TGF-β), and it is regarded as one of the biological factors that play major roles in the process of osteogenesis. Objective: To measure the effect of recombinant human bone morphogenetic protein-2 with an absorbable collagen sponge carrier (rhBMP-2/ACS) on secondary implant stability and study the relation of other parameters like implant receipt jaws, implant diameter, and implant length with implant stability. Methods: Ten participants were enrolled in the study after a selective diagnosis. Forty-seven implants were classified into two groups: the study group included twenty-three dental implants with an additive of rhBMP-2/ACS, and the control group included twenty-four dental implants without an additive. Each patient received at least two implants on each ipsilateral side. The primary implant stability was measured at the surgical phase, and the secondary implant stability was recorded after 16–24 weeks by using the Resonance Frequency Analysis device. Results: There was a weak but not significant correlation between implant dimensions and stability, except in the control group. Concerning the ISQ relation to the jaw, the mandible showed a significant increase in primary stability for the study group compared to that in the control group, but no statistical relation was recorded. Conclusion: The mandible had higher ISO values for primary stability than the maxilla in both groups, with a non-significant connection. The maxilla in both groups had improved secondary stability, whereas the mandible had decreased. (clinicaltrials.gov-NCT05719181).

A Comparative Assessment of Primary Implant Stability Using Osseodensification vs. Conventional Drilling Methods: A Systematic Review.

Osseodensification is a novel biomechanical bone preparation technique that has been established to replace conventional bone drilling and therefore will optimize the implant site. The purpose of this systematic review was to comparethe implant stability obtained by osseodensification drilling to those associated with conventional drilling techniques. An electronic search was performed in the PubMed, Scopus, EMBASE, Cochrane Oral Health Group, and Dentistry and Oral Science Source databases searched through Elton B. Stephens Company (EBSCO) for potentially relevant publications in the English language from January 2013 to December 2022. Randomized clinical trials (RCTs) and non-randomized studies of interventions (NRSIs), contrasting osseodensification drilling with conventional drilling, studies documenting implant stability quotient (ISQ), and studies reporting the immediate outcome and at least three months of follow-up after dental implant placement were included.Two independent investigators evaluated the quality of the reviewed studies to determine the risk of bias using the version 2 of Cochranerisk-of-bias (RoB)toolfor RCTs (RoB 2) and RoB for NRSIs (ROBINS-I). Majority of the studies showed that bone density wassignificantly higher in the osseodensification group.The overall RoB for the NRSIs was reported to be low with respect to confounding, selection, classification, incomplete data, deviance from interventions, outcomeevaluation, and selective reporting. The quality assessment of the RCT studies included in the review using the RoB 2 tool showed a high overall risk. The findings of the current review reveal that osseodensification drilling exhibited higher resonance frequency analysis (RFA) and ISQ values than conventional drilling protocols. Similarly, when osseodensification regions were contrasted with traditional drilling, bone density at the implant surface was augmented.

Optimizing the primary stability of dental implants in type IV bone: in-vitro comparison of machine-driven and ratcheting insertion protocols

Optimizing the primary stability of dental implants in type IV bone: in-vitro comparison of machine-driven and ratcheting insertion protocols

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.

Dependence of Total Ankle Tibial Baseplate Stability Upon Bone Density

Category: Ankle Arthritis Introduction/Purpose: The success of total ankle replacement (TAR) in improving patient outcomes is linked to its initial stability after implantation. Limiting early micromotion between implant and bone improves longer-term stability. Tibial component design fixation features play a critical role in determining early stability, with retention of medial and lateral bone sidewalls and interference press-fit both used to supplement fixation. However, tibial component stability is likely also influenced by regional bone density characteristics, and the exact relationship between the two is not adequately understood. The goal of this study was to investigate how bone density affects tibial component stability and bone-implant interface micromotion between the tibial component of a specific TAR and the distal tibia, by using finite element analysis (FEA) during simulated gait. Methods: A commercially available TAR tibial component baseplate was virtually inserted into a computer model of the distal tibia from two patients with end-stage ankle arthritis. These patients were selected based on having different bone density profiles in the affected ankle. The tibia models were generated from patient CT scans, having a CT density-based inhomogeneous material distribution (Fig. 1a) that allowed for bone compaction after press-fit. The tibial component was modeled as titanium alloy material. Two different fixation cases were simulated using FEA: (1) retained medial/lateral sidewalls + line-to-line fit, and (2) retained sidewalls + 50µm interference press-fit. FEA was performed using body weight-scaled kinetic (forces/moments) profiles representing the stance phase of gait, applied to the distal implant surface, while the proximal tibia was held fixed. Press-fit was simulated prior to gait simulation (interference press-fit cases). Micromotions were defined as displacement differences between bone-implant closest nodal pairs, computed from FEA output. Results: For the case with sidewalls+line-to-line fit, micromotions were largest early and late in the stance phase of gait (Fig. 1b), with the largest micromotions observed at heel strike (0% stance). Dorsiflexion and inversion moments dominate in early stance, stressing the anterior edge of the tibia in contact with the implant, leading to relatively large posterior/lateral gapping (Fig. 1b, inset). The observed differences in micromotion between the two patients correlated with differences in bone quality at the tibia contact surface, particularly around the implant pegs (Fig. 1a). However, when interference press-fit was modeled, the differences in micromotion between the two subjects largely disappeared (Fig. 1c), as adequate bone compaction was generated around the interference regions with sufficient bone quality to resist micromotion (Fig. 1d). Conclusion: This study presents novel insight into the effect of TAR fixation features and the associated micromotion at the bone- implant interface in patients with varying distal tibia bone density. We found the stability of the tibial implant to be considerably affected by surrounding bone quality, but the influence of bone quality on implant stability was minimized when interference press- fit was introduced. While a more comprehensive understanding of TAR implant features and their performance is needed, we believe the results of this study clearly demonstrate the importance of bone quality and particularly implant interference press-fit in the stability of TAR implants.

Determination of the Effect of Periimplantitis-Induced Bone Defects on Implant Stability by Resonance Frequency Analysis Method: An Ex-Vivo Study

Objectives: Periimplantitis is an infectious disease that causes the resorption of the alveolar bone around the implant. This resorption compromises osseointegration by affecting bone-implant contact. This study aimed to determine the effects of experimentally created 3-walled periimplantal defect models at different depths on osseointegration. Materials and Methods: This study was designed as an ex-vivo study. Fresh bovine ribs were used in this study. A total of 14 dental implants of 3.5x10 mm size were placed on the fresh beef rib, and then periimplantal bone defects of different depths were experimentally created. There are a total of 4 groups in the study, they are respectively; healthy group, 1.5 mm deep defect, 2.5 mm deep defect, and 5 mm deep defect group. For all of these groups, osseointegration was evaluated with the Osstell penguin device using the resonance frequency analysis method from four regions of each implant, mesial-distal buccal palatinal, to determine the osseointegration level according to the amount of bone-implant contact. Results: While the highest ISQ values were observed in the healthy group, the difference between the other groups and the healthy group was not statistically significant, except for the 5 mm defect group. The results of the 5 mm defect group were significantly lower than those of the other three groups. Conclusion: It has been observed that there will be a significant decrease in osseointegration according to osstell scores in periimplantal defects with a defect depth of 5 mm