Peri-implant Bone Tissue Research Articles

Stress-strain state of an intraosseous dental implant under stress under unfavorable biomechanical conditions

Biomechanical conditions affect the stress-strain state of teeth, dentures, implants and surrounding tissues, however, some biomechanical processes in implants and covering prosthetic structures have not been sufficiently studied under different operating conditions. The purpose of the study. А comparative analysis of the maximum stresses in titanium implants, abutments and covering ceramic crowns under different biomechanical operating conditions. Material and methods. Three-dimensional mathematical modeling of the stress-strain state of the implant, abutment, crown was carried out using the SolidWork computer program in a model of an implant immersed in a segment of the mandible and covered with a ceramic crown. Load conditions: vertical or inclined 45° with a value of 150 N. Well-known indicators of the physical and mechanical properties of fabrics and structural materials were used. Adverse biomechanical conditions were simulated: a 30% reduction in the length, diameter, length and diameter of the implant; an abutment slope of 15° and 30°; bone resorption by 30% and 50%; increased load by 30%; occlusive supracontact; contact with bone tissue by 50% (immediate load). Results and discussions. In comparison with optimal biomechanical conditions, the stresses in the implant and the covering crown increase under vertical and inclined loads only with an increase in load and the presence of occlusive supracontact. An increase in stresses only in the implant occurs with a decrease in the diameter of the implant, a combined decrease in the diameter and length of the implant, with an abutment tilt, resorption of periimplant bone tissue, incomplete contact of the implant with bone tissue under immediate load. Stress reduction in the implant and the covering crown occurs when the length of the implant decreases. Conclusions. Unfavorable biomechanical conditions in most cases lead to an increase in stresses in the implant, especially with inclined loading; the decrease in stresses in the implant with a decrease in the length of the implant is most likely due to an increase in stresses in the surrounding bone tissue.

Assessment of the advantages and limitations of an innovative silk fibroin scaffold for the reconstruction of the anterior cruciate ligament with preclinical in vitro and in vivo evaluations

The gold standard treatment in anterior cruciate ligament (ACL) reconstruction involves autologous tissue transplantation, but this can have complications. Artificial grafts are an alternative, but the best option is debated. This study aimed to assess the biocompatibility and integration of a silk fibroin textile prosthesis (SF-TP) with peri-implant bone tissue and the native ACL. Twenty-six sheep underwent ACL reconstruction with SF-TP or autologous femoral fascia lata (FFL). Sheep were divided into two groups (3 and 6 months) and retrieved joints processed for histological, morphometrical and mechanical analysis. In vitro, SF-TP showed no cytotoxicity and good cell interaction up to 14 days. Histology revealed fibro-vascular tissue around SF-TP, with a progressive attempt of ligamentous-like tissue formation at 6 months. However, SF-TP group had higher joint damage scores. Micro-CT showed tunnel enlargement in SF-TP group, while FFL group had a decrease. SF-TP reconstructions had lower stiffness and strength (44 % and 64 % decrease) than those of autologous FFL reconstruction and often failed by pull-out from the bone tunnel due to tunnel enlargement. These results indicate poor osteointegration and graft motion with SF-TP, leading to joint damage/bone resorption and reduced mechanical competence. These results do not support the use of SF-TP for ACL reconstruction.

Three-dimensional finite element analysis of the biomechanical behaviour of different dental implants under immediate loading during three masticatory cycles

The study aimed to evaluate the impact of varying modulus of elasticity (MOE) values of dental implants on the deformation and von Mises stress distribution in implant systems and peri-implant bone tissues under dynamic cyclic loading. The implant-bone interface was characterised as frictional contact, and the initial stress was induced using the interference fit method to effectively develop a finite element model for an immediately loaded implant-supported denture. Using the Ansys Workbench 2021 R2 software, an analysis was conducted to examine the deformation and von Mises stress experienced by the implant-supported dentures, peri-implant bone tissue, and implants under dynamic loading across three simulated masticatory cycles. These findings were subsequently evaluated through a comparative analysis. The suprastructures showed varying degrees of maximum deformation across zirconia (Zr), titanium (Ti), low-MOE-Ti, and polyetheretherketone (PEEK) implant systems, registering values of 103.1 μm, 125.68 μm, 169.52 μm, and 844.06 μm, respectively. The Zr implant system demonstrated the lowest values for both maximum deformation and von Mises stress (14.96 μm, 86.71 MPa) in cortical bone. As the MOE increased, the maximum deformation in cancellous bone decreased. The PEEK implant system exhibited the highest maximum von Mises stress (59.12 MPa), whereas the Ti implant system exhibited the lowest stress (22.48 MPa). Elevating the MOE resulted in reductions in both maximum deformation and maximum von Mises stress experienced by the implant. Based on this research, adjusting the MOE of the implant emerged as a viable approach to effectively modify the biomechanical characteristics of the implant system. The Zr implant system demonstrated the least maximum von Mises stress and deformation, presenting a more favourable quality for preserving the stability of the implant-bone interface under immediate loading.

Effect of angled abutments in the posterior maxillary region on tilted implants: a 3D finite element analysis.

The aim of this study was to evaluate the bone tissue effects under dynamic loading using finite element analysis (FEA) for four angled abutments with different deviated palatal lateral tilt angles. A three-dimensional model of the posterior maxillary region and an implant crown model were reconstructed and assembled with a three-dimensional model of the implant, angled abutment, and central screw to create a total of 10 three-dimensional finite element models tilted at , , , and in three groups, and the dynamic loads simulating oral mastication were loaded on the implant crown to analyze the equivalent stresses and strains in the peri-implant bone tissues. Under the dynamic loading, the cortical bone on the buccal side of the implant neck showed different degrees of stress concentration, and the cortical bone stress was much higher than the cancellous bone, and the strain concentration area of each model was located in the bone tissue around the implant neck and base. For the use of angular abutment, under the premise that the cortical bone stresses and strains of the 10 models meet the requirements for use, the peak stresses of 2.907 MPa, 3.018 MPa, and 2.164 MPa were achieved by using the angular abutment to achieve the tilt angles of , , and implantation, which is more advantageous compared with other models.

Socket-shield Technique and immediate implant placement for ridge preservation in the aesthetic region: a 1-year clinical and tomographic follow-up

Objective: To describe the clinical, radiographic and tomographic aspects, as well as complications, success, aesthetic and functional results of an implant placed using the “socket shield” technique. Case Details: Represents a 46-year-old patient, with increased mobility of the crown in the bucco-palatal direction, with indication for extraction replaced by immediate implant. Atraumatic extraction, socket preservation technique and immediate implant placement were performed. The socket-shield technique was designed for placing implants to protect the oral bone and achieve adequate aesthetics. The buccal fragment of the tooth was kept fixed and the implant was placed in contact with the tooth fragment. Cone Bean computed tomography showed bone formation in the buccal aspect 1 year later, and demonstrated stability of the peri-implant bone tissue and replacement of the root remnant by bone. The clinical appearance demonstrated maintenance of peri-implant soft tissues and good aesthetics without gingival retraction. Final considerations: One-year follow-up shows adequate healing and healthy peri-implant tissue, suggesting that the socket-shield technique with immediate implant placement can be an excellent alternative for preserving the vestibular cortex and implant placement, especially in the aesthetic area.

In vitro co-culture models for the assessment of orthopedic antibacterial biomaterials.

The antibacterial biofunctionality of bone implants is essential for the prevention and treatment of implant-associated infections (IAI). In vitro co-culture models are utilized to assess this and study bacteria-host cell interactions at the implant interface, aiding our understanding of biomaterial and the immune response against IAI without impeding the peri-implant bone tissue regeneration. This paper reviews existing co-culture models together with their characteristics, results, and clinical relevance. A total of 36 studies were found involving in vitro co-culture models between bacteria and osteogenic or immune cells at the interface with orthopedic antibacterial biomaterials. Most studies (∼67%) involved co-culture models of osteogenic cells and bacteria (osteo-bac), while 33% were co-culture models of immune cells and bacterial cells (im-bac). All models involve direct co-culture of two different cell types. The cell seeding sequence (simultaneous, bacteria-first, and cell-first) was used to mimic clinically relevant conditions and showed the greatest effect on the outcome for both types of co-culture models. The im-bac models are considered more relevant for early peri-implant infections, whereas the osteo-bac models suit late infections. The limitations of the current models and future directions to develop more relevant co-culture models to address specific research questions are also discussed.

The Use of Mesenchymal Stromal/Stem Cells (MSC) for Periodontal and Peri-implant Regeneration: Scoping Review.

The necessity for regenerating peri-implant and periodontal tissues is increasingly apparent. Periodontal diseases can result in a significant loss of clinical attachment level, and tissue regeneration stands as the ultimate goal of periodontal therapy. With the rise of osseointegration, the prosthetic rehabilitation of missing teeth using dental implants has surged, leading to a frequent need for alveolar bone regeneration around implants. This review assessed studies reporting various sources of mesenchymal stromal/stem cells (MSC) and their potential in regenerating periodontal and peri-implant bone tissue. A search was conducted across seven databases spanning the past decade. Three authors independently screened all identified titles and abstracts for eligibility, generating tables to summarize included studies in animals and humans separately. A total of 55 articles were chosen for final evaluation, showcasing five origins of MSC used in humans and animals for regenerating periodontal tissues and peri-implant bone, using different types of scaffolds. Overall, research from the past decades supports the effectiveness of MSC in promoting periodontal and peri-implant regeneration. However, the impact of MSC on regenerative therapies in humans is still in its initial stages. Future research should optimize MSC application protocols by combining techniques, such as the use of nanomedicine and 3D printing for tissue engineering. Clinical studies should also understand the long-term effects and compare MSC therapies with current treatment modalities. By addressing these areas, the scientific community can ensure that MSC therapies are both safe and effective, ultimately enhancing therapeutic strategies and treatment outcomes in Periodontology and Implantology.

Analysis of peri-implant bone tissue between hydrophilic and rough implant surfaces in spontaneously hypertensive rats treated with losartan.

to evaluate the morphological and functional characteristics of the peri-implant bone tissue that was formed during the healing process by the placement implants using two different surface treatments: hydrophilic Acqua™ (ACQ) and rough NeoPoros™ (NEO), in spontaneously hypertensive (SHR) and normotensive rats (Wistar) whether or not treated with losartan. In total, 96 male rats (48 Wistar and 48 SHR) were divided into eight subgroups: absolute control rough (COA NEO), absolute control hydrophilic (COA ACQ), losartan control rough (COL NEO), losartan control hydrophilic (COL ACQ), SHR absolute rough (SHR NEO), SHR absolute hydrophilic (SHR ACQ), SHR losartan rough (SHRL NEO), and SHR losartan hydrophilic (SHRL ACQ). The rats medicated with losartan received daily doses of the medication. NeoPoros™ and Acqua™ implants were installed in the tibiae of the rats. After 14 and 42 days of the surgery, the fluorochromes calcein and alizarin were injected in the rats. The animals were euthanized 67 days after treatment. The collected samples were analyzed by immunohistochemistry, biomechanics, microcomputerized tomography, and laser confocal scanning microscopy analysis. The osteocalcin (OC) and vascular endothelium growth factor (VEGF) proteins had moderate expression in the SHRL ACQ subgroup. The same subgroup also had the highest implant removal torque. Regarding microarchitectural characteristics, a greater number of trabeculae was noted in the control animals that were treated with losartan. In the bone mineralization activity, it was observed that the Acqua™ surface triggered higher values of MAR (mineral apposition rate) in the COA, COL, and SHRL groups (p<0.05). the two implant surface types showed similar responses regarding the characteristics of the peri-implant bone tissue, even though the ACQ surface seems to improve the early stages of osseointegration.

Isolation of TiNbN wear particles from a coated metal-on-metal bearing: Morphological characterization and in vitro evaluation of cytotoxicity in human osteoblasts.

To improve the wear resistance of articulating metallic joint endoprostheses, the surfaces can be coated with titanium niobium nitride (TiNbN). Under poor tribological conditions or malalignment, wear can occur on these implant surfaces in situ. This study investigated the biological response of human osteoblasts to wear particles generated from TiNbN-coated hip implants. Abrasive particles were generated in a hip simulator according to ISO 14242-1/-2 and extracted with Proteinase K. Particle characteristics were evaluated by electron microscopy and energy dispersive x-ray spectroscopy (EDS), inductively coupled plasma mass spectrometry (ICP-MS) and dynamic light scattering (DLS) measurements. Human osteoblasts were exposed to different particle dilutions (1:20, 1:50, and 1:100), and cell viability and gene expression levels of osteogenic markers and inflammatory mediators were analyzed after 4 and 7 days. Using ICP-MS, EDS, and DLS measurements, ~70% of the particles were identified as TiNbN, ranging from 39 to 94 nm. The particles exhibited a flat and subangular morphology. Exposure to particles did not influence cell viability and osteoblastic differentiation capacity. Protein levels of collagen type 1, osteoprotegerin, and receptor activator of nuclear factor κB ligand were almost unaffected. Moreover, the pro-inflammatory response via interleukins 6 and 8 was minor induced after particle contact. A high number of TiNbN wear particles only slightly affected osteoblasts' differentiation ability and inflammatory response compared to metallic particles. Nevertheless, further studies should investigate the role of these particles in peri-implant bone tissue, especially concerning other cell types.

A digital technique for cloning the emergence profile of the interim to the definitive implant-supported restoration

The subgingival contour of implant-supported restorations is key to ensuring the long-term health of the peri-implant bone and soft tissues. This report describes a step-by-step technique used to accurately clone the emergence profile of the interim crown for the definitive implant-supported restoration.

Emerging factors affecting peri-implant bone metabolism.

Implant dentistry has evolved to the point that standard implant osseointegration is predictable. This is attributed in part to the advancements in material sciences that have led toward improvements in implant surface technology and characteristics. Nonetheless, there remain several cases where implant therapy fails (specifically at early time points), most commonly attributed to factors affecting bone metabolism. Among these patients, smokers are known to have impaired bone metabolism and thus be subject to higher risks of early implant failure and/or late complications related to the stability of the peri-implant bone and mucosal tissues. Notably, however, emerging data have unveiled other critical factors affecting osseointegration, namely, those related to the metabolism of bone tissues. The aim of this review is to shed light on the effects of implant-related factors, like implant surface or titanium particle release; surgical-related factors, like osseodensification or implanted biomaterials; various drugs, like selective serotonin reuptake inhibitors, proton pump inhibitors, anti-hypertensives, nonsteroidal anti-inflammatory medication, and statins, and host-related factors, like smoking, diet, and metabolic syndrome on bone metabolism, and aseptic peri-implant bone loss. Despite the infectious nature of peri-implant biological complications, these factors must be surveyed for the effective prevention and management of peri-implantitis.

RETROSPECTIVE ANALYSIS OF THE DEGREE OF REDUCTION OF PERI-IMPLANT BONE TISSUE DURING IMMEDIATE AND DELAYED DENTAL IMPLANTATION PROTOCOLS

The article presents a comparative analysis of the periimplant bone tissue level reduction indicator in parallel with the study of the success and survival levels of implants installed according to the protocols of immediate, early and delayed implantation with the search for possible statistical or trend associations between the studied parameters described in the preselected pool of scientific works. The purpose of the study is to analyze the differences in the change in periimplant bone tissue reduction indicators under the conditions of implementation of immediate and delayed implantation protocols, as criteria for its prognosis and assessment of success in the process of remote monitoring. Research materials and methods. The search for relevant scientific publications was carried out using the Google Academy search engine, ensuring the ranking of the obtained results according to the criteria of research depth, the completeness of the correspondence of keywords to the title and content of the abstracts of publications, as well as the number of citations in the structure of previously conducted systematic reviews and meta-analyses. The grouping of the results and the assessment of the level and significance of statistical dependencies between the separated parameters of the study were carried out in the Microsoft Excel 2019 table editor software (Microsoft Office 2019). Research results and their discussion. The level of bone tissue reduction in the peri-implant area is one of the determining criteria for the success of installed dental implants in the immediate and remote periods of monitoring, which were previously proposed by many domestic and foreign authors. Existing methods of registering the decrease in the vertical parameters of the bone ridge adjacent to the surface of installed titanium intraosseous supports provide opportunities not only for the numerical calculation of the difference in indicators at different periods of observation, but also for their quantification in the form of calculating the volume loss of bone, its circular reduction, visualization of the geometry of existing saucer-like defects. The value of the index of loss of bone tissue in the periimplant area as a criterion for the success of implantation also increases in cases of complex interpretation of its changes with a number of other studied parameters, such as the cumulative index of survival and success of implants, the relative risk of various forms of complications, statistical associations with potentially determining factors of influence. It is the complex approach to the interpretation of the registered differences between the indicators of the reduction of the level of periimplant bone tissue in the cases of implementation of the protocols of immediate and delayed implantation with the search for possible associations between this criterion and a number of potentially influential factors that ensured the detailed analysis of previously published data. Conclusions. As a result of a detailed analysis, it was possible to establish that the data of previously conducted studies devoted to the comparison of clinical criteria for the effectiveness of the implementation of immediate and other protocols of dental implantation do not allow formulating an unequivocal conclusion regarding the pronounced difference of the investigated indicators during different periods of observation.

Biomechanical effects of different materials for an occlusal device on implant-supported rehabilitation in a tooth clenching situation: A 3D finite element analysis.

The purpose of this 3D finite element analysis was to evaluate the biomechanical effects of different materials used to fabricate occlusal devices to achieve stress distribution in simulated abutment screws, dental implants, and peri-implant bone tissue in individuals who clench their teeth. Eight 3D models simulated a posterior maxillary bone block with three external hexagon implants (Ø4.0×7.0mm) supporting a 3-unit screw-retained metal-ceramic prosthesis with different crown connection (splinting), and the use of an occlusal device (OD). The OD was modeled to be 2-mm thick. ANSYS 19.2 software was used to generate the finite-element models in the pre-and post-processing phases. Simulated abutment screws and dental implants were evaluated by von Mises stress maps, and simulated bone was evaluated by maximum principal stress and microstrain maps by using a finite element software program. The highest stress values in the dental implants and screws were observed in single crowns without OD (M1). Furthermore, the highest stress values and bone tissue strain were found in single crowns without OD (M1). The simulated material for the OD did not cause many discrepancies in terms of the stress magnitude in the simulated dental implant and abutment screw for both single and splinted crowns; however, more rigid materials exhibited lower stress values. The use of OD was effective in reducing stress in the simulated implants and abutment screws and stress and strain in the simulated bone tissue. The material used to simulate the OD influenced the biomechanical behavior of implant-supported fixed prostheses, whereas splints with rigid materials such as PEEK and PMMA exhibited better biomechanical behavior.

Socket shield technique: Stress distribution analysis.

To analyze through finite element analysis the stress distribution in peri-implant bone tissues, implants, and prosthetic components induced by the socket shield (SS) technique in comparison to other techniques used to treat tooth loss. A three-dimensional model of a superior central incisor crown supported by implant was modeled and three different placement conditions were simulated: SS - 2.0-mm-thick root dentin fragment positioned between the alveolar buccal wall and implant; heterologous bone graft (HBG) - bovine bone graft positioned the alveolar buccal wall and implant; and control (C) - implant fully placed in bone tissue of a healed alveolus. The model was restricted at the lateral surfaces of the bone tissue and the following loads were simulated: Both oblique (45°) loads of 100 N on the lingual surface of the crown (maximal habitual intercuspation) and 25.5 N on the incisal edge of the crown (tooth contact during mandibular protrusion) were simultaneously applied. Tensile stress, shear stress, compression, and displacement were analyzed in the cortical bone, trabecular bone, dentin root fragment, and bone graft; while equivalent von Mises stresses were quantified in the implant and prosthetic components. Stress values of SS and HBG in the bone tissues were higher than C, while slight differences within models were observed for dentin root fragment, bone graft, implant, and prosthetic components. The SS technique presented the highest stress concentration in the peri-implant tissues.

Effect of the implant apical exposure and coverage < or ≥ 2mm bone graft on transcrestal sinus floor elevation: a 1- to 7-year retrospective cohort study.

This study aimed to analyze the effect of the apex coverage by the bone graft, including exposure and coverage less than or greater than 2mm on implant survival rate and peri-implant bone and soft tissue remodeling. A total of 264 implants in 180 patients who had undergone transcrestal sinus floor elevation (TSFE) with simultaneous implant placement were included in this retrospective cohort study. Radiographic assessment was used to categorize the implants into three groups based on apical implant bone height (ABH): ≤ 0mm, < 2mm, or ≥ 2mm. The implant survival rate, peri-implant marginal bone loss (MBL) during short-term (1-3years) and mid- to long-term (4-7years) follow-up, and clinical parameters were used to evaluate the effect of implant apex coverage after TSFE. Group 1 had 56 implants (ABH ≤ 0mm), group 2 had 123 implants (ABH > 0mm, but < 2mm), and group 3 had 85 implants (ABH ≥ 2mm). There was no significant difference in the implant survival rate between groups 2 and 3 compared to group 1 (p = 0.646, p = 0.824, respectively). The MBL during short-term and mid- to long-term follow-up indicated that apex coverage could not be considered a risk factor. Furthermore, apex coverage did not have a significant effect on other clinical parameters. Despite limitations, our study found that implant apex coverage by the bone graft, including exposure and coverage levels less than or greater than 2mm, did not significantly affect implant survival, short-term or mid- to long-term MBL, or peri-implant soft tissue outcomes. Based on 1- to 7-year data, the study suggests that implant apical exposure and coverage levels of less than or greater than 2mm bone graft are both valid options for TSFE cases.

Is the clinical performance of internal conical connection better than internal non-conical connection for implant-supported restorations? A systematic review with meta-analysis of randomized controlled trials.

To evaluate bone loss, prosthodontics and biological complications, and implant survival rates of internal conical connections (ICC) compared with internal non-conical connection (INCC) implants. The systematic review was registered on PROSPERO (CRD42021237170). Meta-analysis was performed using standardized mean difference (SMD) for bone loss and risk ratio (RR) for implant survival and complication rates. Risk of bias analysis was evaluated using RoB 2.0, whereas the GRADE tool was used to evaluate the certainty of evidence. A systematic search of the PubMed, Web of Science, Embase, Cochrane, and ProQuest databases was performed independently by two reviewers for articles published up to March 2022. The search criteria had no language or publication date restrictions. Handsearching analysis was performed in the reference list of potential articles. Twelve randomized clinical trials, including 678 patients and 1006 implants (ICC [n=476]; INCC [n=530]), were included. Meta-analysis revealed that ICC demonstrated a lower risk for marginal bone loss (SMD: -0.80mm; p=0.004) and prosthodontics complications (RR: 0.16; p=0.01) than INCC. However, both internal connections demonstrated no significant difference in implant survival rates (RR: 0.54; p=0.10) and biological complications (RR: 0.90; p=0.82). The overall risk of bias revealed some concerns and a low risk of bias for most of the included studies. However, the certainty of evidence of outcomes was considered low to moderate. ICC may be considered a more favorable treatment option than INCC owing to greater preservation of peri-implant bone tissue and a lower probability of prosthodontics complications. However, well-conducted studies with long-term follow-up are warranted.

Strontium-modified titanium substrate promotes osteogenic differentiation of MSCs and implant osseointegration via upregulating CDH2.

Our previous studies showed that strontium (Sr)-modified sand-blasted, large grit, acid etched titanium surface (Sr-SLA) is beneficial for osseointegration; however, the supporting mechanisms have not been explored in detail. Whole-transcriptome RNA sequencing of peri-implant bone tissue was performed, and CDH2 was selected as a key mediator of Sr-SLA-mediated osseointegration. To test this hypothesis, a lentivirus-mediated vector targeting the silencing of the CDH2 gene was used in mesenchymal stem cells (MSCs) prior to seeding on Ti substrates. The effects of CDH2 interference on MSCs vitality, differentiation, and β-catenin signaling activity were evaluated. In vivo, a recombinant adeno-associated virus 9 vector carrying an artificial siRNA that target CDH2 (AAV9-CDH2i) was intravenously injected in mice, followed by tibial surgery with implant placement. Osseointegration were monitored using micro-CT analysis. CDH2 expression in MSCs on Sr-SLA was higher than the control group, which was in parallel with the enhanced cell migration, adhesion, and upregulation of early osteogenic markers. Knocking down CDH2 in MSCs resulted in decreased cell viability and osteogenic differentiation, and the elevated biocompatibility and osteoinductive effect of Sr-SLA were greatly diminished. Surprisingly, Sr-SLA-induced upregulation of CDH2 was not followed by restriction of β-catenin signaling because Sr-SLA also promoted the expression and nuclear translocation of β-catenin. Systemic administration of AAV9-CDH2i effectively knocked down CDH2 expression in bone marrow cells, and in turn, inhibited bone formation induced by Sr-SLA. The results indicated that CDH2 is required for Sr-SLA-mediated bone regeneration, which reveals a new mechanism to explain the osteoinductive effect of Sr-SLA. Thus, biomaterial modifications targeting CDH2 may help improve early osseointegration and bone healing.

Evaluation of Vitamin D isolated or Associated with Teriparatide in Peri-Implant Bone Repair in Tibia of Orchiectomized Rats.

(1) Background: The objective of this study was to evaluate the morphometry of peri-implant bone tissue in orchiectomized rats, treated with vitamin D isolated or associated with teriparatide. (2) Methods: 24 rats were divided into 4 groups: ORQ-orchiectomy, without drug treatment, ORQ+D-orchiectomy, treated with vitamin D, ORQTERI-orchiectomy, treated with teriparatide and ORQTERI+D-orchiectomy, treated with teriparatide + vitamin D. Each animal received an implant in the tibial metaphysis. Euthanasia occurred 60 days after implant surgery. Computed microtomography (micro-CT) was performed to evaluate the parameters of volume and percentage of bone volume (BV, BV/TV), trabecular thickness (Tb.Th), number and separation of trabeculae (Tb.N, Tb.Sp) and percentage of total porosity (Po-tot). Data were subjected to 1-way ANOVA and Tukey post-test, with a significance level of 5%. (3) Results: For the parameters BV, BV/TV, Tb.Th, the ORQTERI+D group showed the highest values in relation to the other groups and for Po-tot, the lowest values were for ORQTERI+D. For Tb.Sp and Tb.N, there was no statistically significant difference when comparing intragroup results (p > 0.05). (4) Conclusions: It was possible to conclude that treatment with vitamin D associated with teriparatide increases bone volume and improves bone quality.

Evaluation of Biodegradable Alloy Fe30Mn0.6N in Rabbit Femur and Cartilage through Detecting Osteogenesis and Autophagy.

Biodegradable iron alloy implants have become one of the most ideal possible candidates because of their biocompatibility and comprehensive mechanical properties. Iron alloy's impact on chondrocytes is still unknown, though. This investigation looked at the biocompatibility and degradation of the Fe30Mn0.6N alloy as well as how it affected bone formation and chondrocyte autophagy. In vivo implantation of Fe30Mn0.6N and Ti6Al4V rods into rabbit femoral cartilage and femoral shaft was carried out to evaluate the degradation of the alloy and the cartilage and bone response at different intervals. After 8 weeks of implantation, the cross-sectional area of the Fe30Mn0.6N alloys lowered by 50.79 ± 9.59%. More Ca and P element deposition was found on the surface Fe30Mn0.6N rods by using energy dispersive spectroscopy (EDS) and scanning electron microscopy (P < 0.05). After 2, 4, and 8 weeks of implantation, no evident inflammatory infiltration was seen in peri-implant cartilage and bone tissue of Fe30Mn0.6N and Ti6Al4V alloys. Also, implantation of Fe30Mn0.6N alloy promoted autophagy in cartilage by detecting expression of LC3-II compared with Ti6Al4V after implantation (P < 0.05). Fe30Mn0.6N alloy also stimulated early osteogenesis at the peri-implant interface compared with Ti6Al4V after implantation (P < 0.05). In the in vitro test, we found that low concentrations of Fe30Mn0.6N extracts had no influence on cell viability. 15% and 30% extracts of Fe30Mn0.6N could upregulate autophagy compared to the control group by detecting beclin-1, LC3, Atg3, and P62 on the basis of WB and IHC (P < 0.05). Also, the PI3K-AKT-mTOR signaling pathway mediated in the upregulation of autophagy of chondrocytes resulting in exposure to extract of Fe30Mn0.6N alloy. It is concluded that Fe30Mn0.6N showed degradability and biocompatibility in vivo and upregulated autophagy activity in chondrocytes.

The circadian clock component BMAL1 regulates osteogenesis in osseointegration.

Congenital and developmental craniofacial deformities often cause bone defects, misalignment, and soft tissue asymmetry, which can lead to facial function and morphologic abnormalities, especially among children born with cleft lip and palate. Joint efforts from oral maxillofacial surgery, oral implantology, and cosmetic surgery are often required for diagnosis and treatment. As one of the most widely performed treatment methods, implant-supported cranio-maxillofacial prostheses have been widely applied in the course of treatment. Therefore, stability of peri-implant bone tissue is crucial for the long-term success of treatment and patients' quality of life. The circadian clock component brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein 1 (BMAL1) was found to be involved in the cell fate of bone marrow mesenchymal stem cells, which were essential in the fixation of titanium implants. This study aimed to investigate the effect of BMAL1 on osteogenesis in osseointegration, providing a brand new solution to increase bone implant conjunction efficiency and implant stability, paving the way for a long-term satisfactory therapy outcome.