Search

Unilateral breast reconstruction is different from bilateral breast reconstruction and breast augmentation, as it requires more consideration of the symmetry between the reconstructed breast and the contralateral breast. However, there are currently no implants specifically targeted to unilateral breast reconstruction, nor is there is objective classification criteria for breast appearance type. A total of 212 breasts from 153 patients were measured. Breast measurements, breast surface curvature distributions, and elliptic Fourier coefficients were used to describe breast features. We objectively classified the appearance of breasts using machine learning and used the resulting cluster centers to construct the most adaptive implants for each type of breast. All of the breasts clustered into 4 types. The implants corresponding to each type of breast were constructed using cluster centers. The resulting cluster centers were then used to choose a suitable implant for patients requiring unilateral breast reconstruction. Contour coefficients were used to evaluate the clustering results, with an average score of 0.53. The two breasts that develop normally in the same person were treated as the same class. The score obtained after statistical classification was 0.47. These results demonstrate that our proposed method can improve the classification of breasts of different shapes. This method provides a foundation for improving the symmetry of unilateral breast reconstruction and the construction and selection of implants.

Dental implants are, nowadays, established surgical devices for the restoration of lost teeth. Considered as an alternative for traditional prosthetic appliances, dental implants surpass them in reliability and patient feedback. Local drug delivery around the implants promotes osseointegration and reduces peri-implantitis. However, there are currently no methods of a multiple, precise topical administration of drugs to the implant area. Engineering coatings on the implants, drug application on carriers during implantation, or gingival pockets do not meet all requirements of dental surgeons. Therefore, there is a need to create porous implants and other medical devices that will allow a multiple drug delivery at a controlled dose and release profile without traumatic treatment. Due to the growing demand for the use of biologically active agents to support dental implant treatment at its various stages (implant placement, long-term use of dental superstructures, treatment of the peri-implant conditions) and due to the proven effectiveness of the topical application of pharmacological biologically active agents to the implant area, the authors would like to present a review and show the methods and devices that can be used by clinicians for local drug administration to facilitate dental implant treatment. Our review concludes that there is a need for research in the field of inventions such as new medical devices or implants with gradient solid–porous structures. These devices, in the future, will enable to perform repeatable, controllable, atraumatic, and repeatable injections of active factors that may affect the improvement of osteointegration and the longer survival of implants, as well as the treatment of peri-implantitis.

Peri-implantitis (PI), a pathological condition associated with plaque, affects the tissues around dental implants. In addition, peri-implant mucositis (PIM) is a precursor to the destructive inflammatory PI and is an inflammation of the soft tissues surrounding the dental implant. It is challenging to eradicate and regulate the PI treatment due to its limited effectiveness. Currently, there is a significant interest in the development and research of additional biocompatible materials to prevent the failure of dental implants. Nanotechnology has the potential to address or develop solutions to the significant challenge of implant failure caused by cytotoxicity and biocompatibility in dentistry. Nanoparticles (NPs) may be used as carriers for the release of medicines, as well as to make implant coatings and supply appropriate materials for implant construction. Furthermore, the bioactivity and therapeutic efficacy of metal NPs in peri-implant diseases (PID) are substantiated by a plethora of in vitro and in vivo studies. Furthermore, the use of silver (Ag), gold (Au), zinc oxide, titanium oxide (TiO2), copper (Cu), and iron oxide NPs as a cure for dental implant infections brought on by bacteria that have become resistant to several medications is the subject of recent dentistry research. Because of their unique shape-dependent features, which enhance bio-physio-chemical functionalization, antibacterial activity, and biocompatibility, metal NPs are employed in dental implants. This study attempted to provide an overview of the application of metal and metal oxide NPs to control and increase the success rate of implants while focusing on the antimicrobial properties of these NPs in the treatment of PID, including PIM and PI. Additionally, the study reviewed the potential benefits and drawbacks of using metal NPs in clinical settings for managing PID, with the goal of advancing future treatment strategies for these conditions. [ABSTRACT FROM AUTHOR]

The presented study deals with the analysis of the tribological behaviour of the Ti6Al4V alloy manufactured conventionally. The study aimed to verify whether the titanium alloy is suitable for use as a contact material in small joint implants, as additive manufacturing of this alloy can in the future provide certain benefits, such as individualization and simplification of the implant construction, or controlled porosity. The tested pair consisted of a pin and a glass plate lubricated with model synovial fluid. The contact area was observed with colorimetric interferometry. Alongside film thickness, friction, and wear scars were measured. From the designed experimental conditions, the titanium alloy was not able to create a sufficiently thick lubrication film to overcome its surface roughness and damage to contact surfaces occurred. Friction was comparable for all the tested configurations. The application of conventionally manufactured titanium alloy as a contact surface in small joint implants seems to not be suitable since its performance fell short when compared to conventional cobaltous alloy. Nevertheless, there are various alternative methods available, such as unconventional manufacturing, polishing, surface texturing, and coating. [ABSTRACT FROM AUTHOR]

Copyright of Acta Stomatologica Croatica is the property of Acta Stomatologica Croatica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

OBJECTIVE To improve upon the toggle-pin implant construction and develop a repeatable surgical technique to achieve coxofemoral stabilization in mature cattle. ANIMALS 9 adult bovine cadaveric coxofemoral joints, 8 bovine femurs, 2 beef calf cadavers. PROCEDURES Ultimate tensile strength and elongation at failure were measured for the native ligament of the head of the femur (LOHOF) harvested up to 48 hours after death, and the prosthetic prototype utilizing stainless-steel cable and prosthetic prototype utilizing nylon leader line were compared. Bovine femurs were utilized to locate the ideal and repeatable trajectory of the prosthetic ligament to exit at the origin of the LOHOF. Using fluoroscopy, thawed calf cadavers with radiopaque markers placed at sites of origin and insertion of the LOHOF were positioned to assess limb angle to maximize joint isometry resulting in the ideal placement of the LOHOF prosthesis. The study was performed between February 1, 2020, and December 1, 2021. RESULTS The stainless-steel prototype had a significantly higher ultimate tensile strength and significantly decreased elongation at failure when compared to the LOHOF, while the nylon-based prototype had significantly decreased tensile strength and elongation at failure compared to the LOHOF. Therefore, neither prototypes were biomechanically similar to LOHOF. CLINICAL RELEVANCE The stainless-steel prosthetic prototype shows promise to provide superior stabilization to the luxated coxofemoral joint. [ABSTRACT FROM AUTHOR]

Copyright of Implantologie is the property of Quintessenz Verlags GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigates the enhancement of mechanical and tribological behavior in polymethyl methacrylate (PMMA) composites reinforced with graphene oxide (GO) as a solid lubricant filler for advanced biomedical applications, particularly dental implants. PMMA/GO composites were prepared with varying weight percentages of GO (0, 0.2, 0.5, 0.7, and 1 wt. %) to assess their impact on material performance. A noteworthy improvement in both tensile strength and Young's modulus was detected, reaching up to 141% and 10.6%, respectively, at optimized GO loadings of 1%. Microstructural analysis utilizing scanning electron microscopy for the worn surface revealed enhanced dispersion and interfacial adhesion between GO and the PMMA matrix, reinforcing mechanical coherence. Tribological properties also demonstrated enhancement, with PMMA composites containing 1 wt. % GO exhibiting optimal mechanical and tribological characteristics compared to lower weight fractions. Moreover, microscopic examination revealed a shift in the wear mechanism of the PMMA-GO composite, which was attributed to the lower friction coefficient obtained by GO integration. [ABSTRACT FROM AUTHOR]

Clinical indications for the Ti-Zr alloy (Roxolid®) mini-implants (MDIs) in subjects with narrow ridges are still under review. The aim was to analyze peri-implant and posterior edentulous area strains dependent on the MDI number, splinting status, loading force, and loading position. Six models were digitally designed and printed. Two, three, or four Ti-Zr MDIs, splinted with a bar or unsplinted (single units), supported mandibular overdentures (ODs), loaded with 50–300 N forces unilaterally, bilaterally, and anteriorly. The artificial mucosa thickness was 2 mm. Strain gauges were bonded on the vestibular and oral peri-implant sides of each MDI, and on the posterior edentulous area under the ODs. Loadings were performed through the metal plate placed on ODs' artificial teeth (15 times repeated). Arithmetic means with standard deviations and the significance of the differences (MANOVA, Sheffe post hoc) were calculated. Different MDI numbers, loading positions, forces, and splinting elicited different peri-implant microstrains. In the two-MDI models, 300 N force during unilateral loading elicited the highest microstrains (almost 3000 εμ on the loaded side), which can jeopardize bone reparation. On the opposite side, >2500 εμ was registered, which represents high strains. During bilateral loadings, microstrains hardly exceeded 2000 εμ, indicating that bilateral chewers or subjects having lower forces can benefit from the two Ti-Zr MDIs, irrespective of splinting. However, in subjects chewing unilaterally, and inducing higher forces (natural teeth antagonists), or bruxers, only two MDIs may not be sufficient to support the OD. By increasing implant numbers, peri-implant strains decrease in both splinted and single-unit MDI models, far beyond values that can interfere with bone reparation, indicating that splinting is not necessary. When the positions of the loading forces are closer to the implant, higher peri-implant strains are induced. Regarding the distal edentulous area, microstrains reached 2000 εμ only during unilateral loadings in the two-MDI models, and all other strains were lower, below 1500 εμ, confirming that implant-supported overdentures do not lead to edentulous ridge atrophy. [ABSTRACT FROM AUTHOR]

Thanks to the use of new digital technologies and innovations in materials, there has been an increasing interest in subperiosteal implants. These implants are considered to be helpful for the rehabilitation of severe jaw atrophies, as they overcome some disadvantages of endosseous implantology. In the present clinical retrospective study, 18 patients were treated and the clinical outcomes of the treatment were recorded after 12 months of follow-up. [ABSTRACT FROM AUTHOR]

Abstract Peri-implantitis (PI), a pathological condition associated with plaque, affects the tissues around dental implants. In addition, peri-implant mucositis (PIM) is a precursor to the destructive inflammatory PI and is an inflammation of the soft tissues surrounding the dental implant. It is challenging to eradicate and regulate the PI treatment due to its limited effectiveness. Currently, there is a significant interest in the development and research of additional biocompatible materials to prevent the failure of dental implants. Nanotechnology has the potential to address or develop solutions to the significant challenge of implant failure caused by cytotoxicity and biocompatibility in dentistry. Nanoparticles (NPs) may be used as carriers for the release of medicines, as well as to make implant coatings and supply appropriate materials for implant construction. Furthermore, the bioactivity and therapeutic efficacy of metal NPs in peri-implant diseases (PID) are substantiated by a plethora of in vitro and in vivo studies. Furthermore, the use of silver (Ag), gold (Au), zinc oxide, titanium oxide (TiO2), copper (Cu), and iron oxide NPs as a cure for dental implant infections brought on by bacteria that have become resistant to several medications is the subject of recent dentistry research. Because of their unique shape-dependent features, which enhance bio-physio-chemical functionalization, antibacterial activity, and biocompatibility, metal NPs are employed in dental implants. This study attempted to provide an overview of the application of metal and metal oxide NPs to control and increase the success rate of implants while focusing on the antimicrobial properties of these NPs in the treatment of PID, including PIM and PI. Additionally, the study reviewed the potential benefits and drawbacks of using metal NPs in clinical settings for managing PID, with the goal of advancing future treatment strategies for these conditions. Graphical abstract

Copyright of Travma is the property of Zaslavsky O.Yu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Implant-based rehabilitation is a clinical challenge, especially in the esthetic area. Numerous factors influence the outcome of the rehabilitation; however, the two main factors are the bone and soft-tissue deficiencies at the intended implant site. Peri-implant soft tissue complications can arise from a combination of factors that can be summarized as two categories: diagnostic errors and surgical planning management errors. Most of the complications can be corrected after each step of the treatment and even after the delivery of the prosthetic restoration with adequate soft tissue management in order to give the patient an esthetically pleasing outcome. The aims of this article were: to present the current literature, to propose a clinical checklist to guide clinicians in evaluating the prognosis of the treatment utilizing soft tissue grafting, and to illustrate a case series partially employing the proposed clinical checklist. The proposed checklist could be helpful in evaluating the prognosis of the treatment utilizing only soft tissue grafting. In clinical cases in which the prognosis is classified as good, soft tissue management could be a viable treatment option before attempting more radical procedures like implant removal. [ABSTRACT FROM AUTHOR]

Purpose: To compare the biomechanical behaviors of different surgical options that are preferred for implant-supported fixed prosthetic rehabilitation of the atrophic edentulous maxilla. Materials and Methods: A 3D finite element analysis (FEA) model was generated from the computed tomography data of a patient with an atrophic edentulous maxilla. Four scenarios were created in the atrophic maxilla. In model 1, the maxilla was reconstructed with an onlay bone graft harvested from the anterior iliac crest, and sinus augmentation procedures were performed. Standard dental implants were placed in the lateral incisor, first premolar, and first molar regions on each side. In model 2, the anterior part of the atrophic maxilla was reconstructed with an onlay bone graft harvested from the mandibular ramus, and zygomatic implants were placed in the posterior part of the maxilla. In models 3 and 4, two-piece subperiosteal implants made of titanium and polyether ether ketone (PEEK) materials, respectively, were placed in the atrophic maxilla. All implants were loaded with 150-N and 50-N forces in vertical and lateral directions, respectively. Stress accumulation on bones, implants, abutments, and prosthetic frameworks was investigated. Results: The tensile stress in both cortical and trabecular bone was highest in the iliac bone grafting group under vertical loading. The compressive stress in both cortical and trabecular bone was the highest in the PEEK subperiosteal implant model, and the compressive stress value on the trabecular bone exceeded the strength of the trabecular bone. The highest von Mises stress in the implants was obtained in the iliac bone grafting group under vertical loading. The highest stress value in the abutments was detected for the titanium subperiosteal implant. The highest von Mises stress in the prosthetic framework was detected in the titanium subperiosteal implant group, under both vertical and lateral loading. Conclusion: Based on the stress accumulation results of the four different scenarios, it can be seen that there is no ideal treatment modality for the fixed implant-supported prosthetic rehabilitation of the atrophic edentulous maxilla. Various intraoperative and prosthetic modifications are suggested to decrease the risk of biomechanical complications during long-term follow-up. [ABSTRACT FROM AUTHOR]

Orbital implants are used in such procedures as a method by which the natural void created by the removal of an eye can be filled to restore structural and mechanical stability in the region. Highly biocompatible, easy-to-process, relatively inexpensive, chemically and structurally nonabrasive material with high functionality is yet to be proposed for this application. This study investigates a new semibiodegradable, porous polyurethane/beta-tricalcium phosphate composite as a potential material for orbital implant construction. The orbital implant material presented is composed of polyurethane and ceramic components. Isocyanate, caprolactone monomers, catalyst, and deionized water were used for the preparation of polyurethane. The porosity is observed 96.93% with a 267 ± 25 µm average pore size. Young’s Modulus was around 50 MPa. Composite implants showed no cytotoxic, apoptotic, and necrotic effects. This matrix, with a biocompatible, porous, and light-weight structure, and with both suitability for tissue infiltration and incorporation potential, holds great promise. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to perform a biomechanical analysis to compare different medial column fixation patterns for valgus pilon fractures in a case-based model. Methods: Based on the fracture mapping, 48 valgus pilon fracture models were produced and assigned into four groups with different medial column fixation patterns: no fixation (NF), K-wires (KW), intramedullary screws (IS), and locking compression plate (LCP). Each group contained wedge-in and wedge-out subgroups. After fixing each specimen on the machine, gradually increased axial compressive loads were applied with a load speed of one millimeter per minute. The maximum peak force was set at 1500 N. Load-displacement curves were generated and the axial stiffness was calculated. Five different loads of 200 N, 400 N, 600 N, 800 N, 1000 N were selected for analysis. The specimen failure was defined as resultant loading displacement over 3 mm. Results: For the wedge-out models, Group-IS showed less displacement (p < 0.001), higher axial stiffness (p < 0.01), and higher load to failure (p < 0.001) than Group-NF. Group-KW showed comparable displacement under loads of 200 N, 400 N and 600 N with both Group-IS and Group-LCP. For the wedge-in models, no statistical differences in displacement, axial stiffness, or load to failure were observed among the four groups. Overall, wedge-out models exhibited less axial stiffness than wedge-in models (all p < 0.01). Conclusions: Functional reduction with stable fixation of the medial column is essential for the biomechanical stability of valgus pilon fractures and medial column fixation provides the enough biomechanical stability for this kind of fracture in the combination of anterolateral fixation. In detail, the K-wires can provide a provisional stability at an early stage. Intramedullary screws are strong enough to provide the medial column stability as a definitive fixation. In future, this technique can be recommended for medial column fixation as a complement for holistic stability in high-energy valgus pilon fractures. [ABSTRACT FROM AUTHOR]

Currently, there are no resources to support culturally and linguistically diverse (CALD) women with breast cancer to make decisions about undergoing breast reconstruction (BR). This study evaluated the usability and acceptability of decision aids (DAs) for Vietnamese- and Arabic-speaking women. This two-phase qualitative recruited Vietnamese- (Phase 1) and Arabic-speaking (Phase 2) adult (age ≥ 18 years) women who were diagnosed with breast cancer and could read Vietnamese/Arabic. Women participated in either think-aloud telephone interviews (Phase 1) or semi-structured telephone interviews (Phase 2) and provided feedback on the DA. Interviews were audio-recorded, translated, and transcribed from Vietnamese/Arabic to English, and inductive thematic analysis was undertaken. Additionally, Arabic-speaking women completed the Preparation for Decision Making (PrepDM) scale in Round 2. Twenty-five women were recruited in two phases (Phase 1: Vietnamese-speaking women, n = 14; Phase 2: Arabic-speaking, n = 11). Three themes were developed in Phase 1: (1) DA content and reception; (2) linguistic attributes and cultural appropriateness; and (3) factors that improve the DAs' impact. Three themes were developed in Phase 2: (1) varying perceptions of DA content; (2) linguistic and cultural suitability of information; and (3) impact of DA on decision making. Women from both phases identified areas for improvement: minimising the use of medical terminology, considering the cultural taboos associated with the word 'breast', and addressing remaining information gaps. Both language DAs were generally perceived as acceptable and useful in providing information about BR options and prompting women's reflections about the suitability of BR as part of their treatment. The mean PrepDM score for Arabic-speaking women in Round 2 was 4.8/5 (SD = 0.3). Further work is needed to ensure that culturally adapted DAs take into account the myriad of information needs and health literacy levels. The key role of healthcare professionals in shared decision making among CALD populations should also be considered. [ABSTRACT FROM AUTHOR]

In this paper, for the first time, the nanostructures of metal alloy Ti6Al4V implants produced by the selective laser melting (SLM) technique were examined using the SAXS method, depending on the annealing temperature, and the relationship between these nanostructures and bioactivity was examined for the first time. Annealing process in this technique increases the durability and makes alloys more suitable for processing. In this study, in order to understand the effect of annealing temperature on the nanostructure, five identical samples without annealing and five identical samples annealed at different temperatures (T = 780, 840, 1040 °C) were examined and compared with each other structurally. Beside of nanoscopic SAXS analyses, SEM imaging and macrophotography techniques were also used as supporting evidence. Additionally, antimicrobial test was applied to determine the antimicrobial properties of the samples, too. As a result, the best annealing temperature (840 °C) was determined to prepare implant materials with uniform and homogeneously distributed nanospherical (Rg = 13.4 ± 0.3 nm radius) formations. The morphologies, sizes, radial electron densities, and distance distributions of the nanoaggregations in the implant content, determined as a result of SAXS data evaluations, constituted nanoscopic findings. It was also shown that this nanostructured implant has an antibiofilm effect against S.aureus. [ABSTRACT FROM AUTHOR]

Copyright of Advanced Textile Technology is the property of Zhejiang Sci-Tech University Magazines and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We performed metallographic evaluations of implants, removed during revision hip arthroplasty. The implants were evaluated for electrochemical potentials and the presence of wear products on the implants surface. A total of 50 patients (50 hips) underwent revision hip arthroplasty during the years 2007-2009 for aseptic loosening. The mean follow-up from primary hip replacement to revision was 10.1 years (from six months to 17 years). All hip joint implants removed during the revision arthroplasty were submitted to metallographic analysis and all heads were submitted to analysis under a scanning microscope. All polyethylene (PE) cups and inserts showed numerous features of wear (friction wear, plastic deformation and creeping, fatigue wear and degradation), six PE cups were broken. In six ceramic cups, only friction wear features were found; one of them was mechanically broken. In all heads articulating on PE not one had any mechanical damage. Heads of ceramic implants in ceramic-ceramic articulation undergo abrasive wear. None of the studied stems (cemented or uncemented) revealed any features of wear. Areas of titanium crystals (formed by electrolytic sedimentation of metals) were macroscopically identified on the sliding surface of six heads that was confirmed by chemical composition and scanning microscope. In the course of prosthesis use, wear products are produced and transferred onto the sliding surfaces of implant heads and cups via ways other than purely mechanical contact. It has been confirmed that metals used for implant construction, make galvanic cells with different electrochemical potentials. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Taibah University Medical Sciences is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: We compared the raw Ti–Al–V super alloy transpedicular implant screws with boronized and surface-hardened transpedicular implant screws. OBJECTIVE: To improve patients' postoperative prognosis with the production of harder and less fragile screws. METHODS: Surface hardening was achieved by applying green-body encapsulation of the specimen with elemental boron paste which is sintered at elevated temperatures to ensure the boron-metal diffusion. Boron transported into the Ti–Al–V super alloy matrix gradually while suppressing aluminum and a homogeneously boronized surface with a thickness of ∼15 microns was obtained. The uniform external shell was enriched with TiB2, which is one of the hardest ceramics. The Ti-Al-V core material, where boron penetration diminishes, shows cohesive transition and ensures intact core-surface structure. RESULTS: Scanning electron microscope images confirmed a complete homogeneous, uniform and non-laminating surface formation. Energy-dispersive X-ray monitored the elemental structural mapping and proved the replacement of the aluminum sites on the surface with boron ending up the TiB2. The procedure was 8.6 fold improved the hardness and the mechanical resistance of the tools. CONCLUSIONS: Surface-hardened, boronized pedicular screws can positively affect the prognosis. In vivo studies are needed to prove the safety of use. [ABSTRACT FROM AUTHOR]

Dental implant fracture is closely connected to the stress buildup surrounding the implant system during static loading. In areas where the cross-section of the implant rapidly changes or where the geometry of the implant system has discontinuities, stress concentrations arise. Therefore, the implant's design is crucial in preventing early failure of the implant system, including fracture, screw loosening, and increased leakage, in addition to reducing stresses at the implant–abutment interface. In the current work, three-dimensional (3D) models of mechanically connected Ti6-Al-4V implant systems in various dimensions were constructed. Finite element analysis (FEA) was used to conduct a stress study of the created implants under actual acting force static loading conditions in accordance with ISO 14801. In the created models, design elements including implant screw type, thickness, and taper angle of abutment were modified in order to increase the longevity of the implants. The results show that the equivalent stress level was dramatically reduced from 596.22 MPa to 212.72 MPa in the implant model, which exhibits a more homogeneous stress pattern under static loading conditions. By increasing the implant wall thickness from 0.15 mm to 0.40 mm in the region adjacent to the abutment, the stress levels, especially at the internal screw, were significantly reduced. Also, the design modification in Model B, establishing contact between the abutment and the upper part of the conical surface of the implant, resulted in a decrease in stress in the internal screw. Thus, enhanced homogeneity in stress distribution not only improves the harmony between the implant and surrounding tissues, thus increasing patient comfort and reducing the risk of complications, but also holds promise for the development of new implants capable of withstanding the forces encountered in the oral environment due to the relatively smoother stress transmission observed in this model. [ABSTRACT FROM AUTHOR]

Clinical fixation screws are common in clinical practices to fix mandibular condyle fractures. Evidence suggests significance of 'working length' that is, distance between proximal and distal fixation screws in proximity to the fracture in orthopaedic implant design. In pursuit of stable implant-bone construct, this study aims to investigate the biomechanical performance of each configuration considered in the study and provide an optimal working length between the screws for clinical reference. Finite element models of virtually designed broken condyle as type 'B' were simulated and analysed in ANSYS Workbench. Screws are implanted according to previous literature at five varied distances 'd' maintaining five different ratios with the fracture length 'D'. Based on a literature review, boundary conditions, muscle traction forces and non-linear contacts were assigned to obtain precise results. Each case is considered an individual configuration and von Mises distribution, microstrain in bone, screw-bone interface micromotion and fracture dislocation were evaluated for all these configurations. Stress-shielding phenomenon is observed for maximum von Mises stresses in bone. Microstrain concentration was significant in cancellous bone in the vicinity of the screw around the fracture line. Configurations were compared based on the stress-strain along with micromotion to support the required amount of osseointegration between implant and bone. Presented data from all five conditions supported the assumption that under physiological loading conditions, the D3 configuration provided stability for fracture healing. Further research on screw shapes, diameters and material properties, or investigating the direction of forces within the screws could provide further insight into this topic. [ABSTRACT FROM AUTHOR]

Titanium has an extensive record of serving as an excellent option for the material used in implant construction. It has been demonstrated that certain Ti alloys are superior to other types of material in every respect. Better osseointegration is a critical component for implants, and titanium's biocompatibility, corrosion tribology, microstructure, and cell adhesion mechanism have been the subject of intensive study for several years. Significant strides have been made in dental implant research thanks to the company's production process, the analysis of the material's properties, and the creation of new innovative alloys. More studies should be done at the dentistry site on human bone production to determine its compatibility with metals and alloys. In this article, we will discuss the latest advancements that have been made regarding biocompatibility, corrosion resistance, mechanical stability, surface chemistry, and electromechanical behavior of titanium dental implants. In addition to that, we also discuss recent developments in dental implant production, such as additive manufacturing technology, as well as implant characterization techniques, such as microstructure characterization, mechanical testing, biocompatibility tests, and the clinical use of titanium dental implants.

Proximal junction kyphosis (PJK) is a common imaging finding after long-level fusion, and proximal junctional failure (PJF) is an aggravated form of the progressive disease spectrum of PJK. This includes vertebral fracture of upper instrumented vertebra (UIV) or UIV+1, instability between UIV and UIV+1, neurological deterioration requiring surgery. Many studies have reported on PJK and PJF after long segment instrumentation for adult spinal deformity (ASD). In particular, for spine deformity surgeons, risk factors and prevention strategies of PJK and PJF are very important to minimize reoperation. Therefore, this review aims to help reduce the occurrence of PJK and PJF by updating the latest contents of PJK and PJF by 2023, focusing on the risk factors and prevention strategies of PJK and PJF. We conducted a search on multiple database for articles published until February 2023 using the search keywords “proximal junctional kyphosis,” “proximal junctional failure,” “proximal junctional disease,” and “adult spinal deformity.” Finally, 103 papers were included in this study. Numerous factors have been suggested as potential risks for the development of PJK and PJF, including a high body mass index, inadequate postoperative sagittal balance and overcorrection, advanced age, pelvic instrumentation, and osteoporosis. Recently, with the increasing elderly population, sarcopenia has been emphasized. The quality and quantity of muscle in the surgical site have been suggested as new risk factor. Therefore, spine surgeon should understand the pathophysiology of PJK and PJF, as well as individual risk factors, in order to develop appropriate prevention strategies for each patient. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this pilot study is to compare gene expression in mucosa around dental implants with zirconia abutment to titanium and investigate presence of particles in mucosa samples and on implant heads. Material and Methods: Ten patients with a single implant supported prosthesis connected to zirconia or titanium abutments were invited at the five-year control. A clinical examination and a survey on experience of function and appearance were conducted. A mucosa biopsy taken in close vicinity to the implant were analysed by real-time polymerase chain reaction (qPCR) and presence of particles in a scanning electron microscope/energy-dispersive X-ray spectroscope (SEM/EDX). Cytological smear samples were collected and analysed through inductively coupled plasma mass spectrometry (ICP-MS) to investigate presence of particles on implant heads. Results: In total, 9 patients participated in the study, five with titanium abutments and four with zirconia abutments. All patients were satisfied with function and aesthetics. Titanium and iron particles were detected in mucosa biopsies. The ICP - MS analysis demonstrated presence of zirconia and titanium. Several proinflammatory genes were upregulated in the zirconia abutment group. Conclusions: Around zirconia abutments a slight increase in proinflammatory response and amount of wear particles was seen as compared to titanium. Wear particles of titanium were present in all soft tissue samples, however zirconia particles only in the samples from implants heads/mucosa with zirconia abutments. [ABSTRACT FROM AUTHOR]

Titanium and its alloys are widely used in various implant applications due to their biocompatibility and the ability to modify their alloy compositions. Because of its minimal impact on the human body and its resistance to chemical reactions, titanium has become popular in the field of dentistry in recent years and is considered a safe option for implant applications. Artificial dental crowns and dental root implant prostheses are typically produced using titanium alloys (Ti-6Al-4V). In this study, the FE package software ANSYS was used to investigate temperature and stress distribution in a dental implant prosthesis. 3D model was created and subjected to two different input conditions: two different temperatures (45° C and 10° C) under the 100 N compressive load and a fluid (beverage + air) flow rate of 1 m/s. The highest temperature was considered as food/beverage taken from a stove, while the lowest temperature was considered as beverage temperature taken out of the refrigerator. Based on the results of the thermal, von Mises stress, and total deformation analyses, it was determined that the implant prosthesis did not conduct heat well to the tooth root and had good compressive strength (48 MPa) under the load, which was better than its yield strength. Furthermore, it was found that a significant portion of the applied load was borne by the artificial dental crown. The aim of this study is to investigate the thermal and mechanical properties of the Ti-6Al-4V alloy, the behavior that is occur when it is exposed to temperature and compression stress. In this context, it is aimed to determine the incompatibilities that may occur at the bone-implant interface and to emphasize that mechanical compatibility is an important issue besides biocompatibility. [ABSTRACT FROM AUTHOR]

10.3390/s22103641 19 Ma C.Z.-H., Ling Y.T., Shea Q.T.K., Wang L.-K., Wang X.-Y., Zheng Y.-P. 10.3390/bioengineering9100574 28 Wang H., Gao C., Fu H., Ma C.Z.-H., Wang Q., He Z., Li M. Automated Student Classroom Behaviors' Perception and Identification Using Motion Sensors. 2023; 10: 315 15 He C., Yang J.-T., Zheng Q., Mei Z., Ma C.Z.-H. How do Paraspinal Muscles Contract during the Schroth Exercise Treatment in Patients with Adolescent Idiopathic Scoliosis (AIS)? 2018; 25: 20-27. 10.1080/10749357.2017.1380339 22 Li H., Huang H., Ren S., Rong Q. Leveraging Multivariable Linear Regression Analysis to Identify Patients with Anterior Cruciate Ligament Deficiency Using a Composite Index of the Knee Flexion and Muscle Force. [Extracted from the article]

Objectives: The primary aim was to compare the amount of bone height change that occurs around the tooth and the implant when having tooth-implant-supported prosthetic restorations versus bone height change that appears around implants in only implant-supported prosthetic restorations. The secondary aim was to examine the influence of various factors such as the number of teeth involved in the construction, their endodontic treatment, number of implants, the type of implantology construction, the jaw in which the construction is located, the condition of the opposite jaw, gender, age, and working time, as well as to examine whether the initial bone level influenced the amount of change in bone height itself. Materials and methods: With a total of 50 respondents, 25 X-ray panoramic images were representing tooth-implant-supported prosthetic restorations, while the other 25 were representing implant-supported prosthetic restorations. Bone measures were taken (from enamel-cement junction/implant neck to the most apical bone point) from 2 panoramic radiographs. The first one is immediately after the implant placement and the second and the last one again in half a year up to seven years after, depending on the time when the photo was taken for each patient. The obtained difference represented the bone resorption, the bone formation, or a state without change. Influence of different factors, such as sex, age of the patient, working time, the number of teeth involved in the construction, endodontic treatment, number of implants, the type of implant construction, the jaw where the construction is located, the condition of the opposite jaw, as well as the initial bone condition, was examined. During the statistical analysis, frequency tables, basic statistical parameters, the Mann-Whitney U test, the Kruskal-Wallis Anova, Wilcoxon test, and regression analysis were used, and the results were presented in tabular form and the form of the Pareto diagram of t-values. Results: No statistically significant difference in bone change (whether we are talking about the place of the implant (-0.359±1.009 and median value 0.000), the place of a tooth (-0.428±0.746 and median value -0,150) in tooth-implant supported restorations, or the place of the implant in case of implant-supported structures (-0,059±0,200 and median value -0,120)) was proven. When talking about the influence of other factors, by regression analysis, the number of implants was shown to be the only factor with a statistically significant influence (β=0.54; P=0.019) in a change of bone level, but only when talking about implant-supported restorations. Conclusion: No significant difference was proven between bone height change, neither around the tooth nor the implant in tooth-implant-supported prosthetic restorations compared to the bone height changes around the implant in only implant-supported prosthetic restorations. Among all the examined factors, the number of implants has shown to have statistically significant contribution to the amount of bone height change in implant-supported prosthetic restorations.

The immuno-compatibility of implant materials is a key issue for both initial and long-term implant integration. Ceramic implants have several advantages that make them highly promising for long-term medical solutions. These beneficial characteristics include such things as the material availability, possibility to manufacture various shapes and surface structures, osteo-inductivity and osteo-conductivity, low level of corrosion and general biocompatibility. The immuno-compatibility of an implant essentially depends on the interaction with local resident immune cells and, first of all, macrophages. However, in the case of ceramics, these interactions are insufficiently understood and require intensive experimental examinations. Our review summarizes the state of the art in variants of ceramic implants: mechanical properties, different chemical modifications of the basic material, surface structures and modifications, implant shapes and porosity. We collected the available information about the interaction of ceramics with the immune system and highlighted the studies that reported ceramic-specific local or systemic effects on the immune system. We disclosed the gaps in knowledge and outlined the perspectives for the identification to ceramic-specific interactions with the immune system using advanced quantitative technologies. We discussed the approaches for ceramic implant modification and pointed out the need for data integration using mathematic modelling of the multiple ceramic implant characteristics and their contribution for long-term implant bio- and immuno-compatibility. [ABSTRACT FROM AUTHOR]

Background: Paediatric caudal anaesthesia is an established technique. Commercially, only one paediatric caudal part-task trainer (PTT) exists. In the South African context, access to caudal block simulation training is lacking. A reusable paediatric caudal anaesthesia trainer was produced through three-dimensional (3D) printing, silicone moulding and gelatine casting. This study compared the local and commercial trainers to patient-based anatomy, by specialist opinion. This was done to validate the locally manufactured PTT for potential anaesthesia training. Methods: Specialist anaesthesiologists (n = 30) randomly performed a caudal block on each trainer. Visual analogue scales were completed for each PTT, comparing four variables to real patient anatomy (i.e. palpation of bony landmarks and sacral hiatus; simulation of soft tissue; loss of resistance to needle insertion into the epidural space; overall similarity of the experience to caudal injection on a real patient). As a secondary outcome, correct needle placement was confirmed using ultrasound on the 3D-printed trainer. Results: Bony landmark and sacral hiatus palpation rated a median of 36.50% for the 3D-printed trainer and a mean of 36.58% for the Life/form® trainer (p = 0.28). Soft tissue simulation rated a median of 56.75% for the 3D-printed trainer and a mean of 43.23% for the Life/form® trainer (p = 0.11). Loss of resistance rated a median of 56% and 48.50% for the 3D-printed and Life/form® trainers, respectively (p = 0.44). Overall similarity of the experience to real anatomy rated a median of 52% for the 3D-printed trainer and a mean of 41.97% for the Life/form® trainer (p = 0.23). Simultaneous comparison of all four variables between the two trainers showed no statistically significant difference (p = 0.64). Ultrasound confirmed correct needle placement for 86.67% of participants on the 3D-printed trainer. Conclusion: The two caudal anaesthesia PTTs demonstrated no significant difference in performance, as judged by specialist opinion. Both models need improvement in terms of fidelity, compared to real anatomy. Using 3D printing to produce PTTs may improve local availability. [ABSTRACT FROM AUTHOR]