Search Results (883)

This in vivo animal study aimed to evaluate the effects of two different implant placement micromotor systems on implant stability and removal torque. In a within-animal crossover design, twenty titanium implants (AnyOne fixture; internal type; diameter, 3.5 mm; length, 7.0 mm; Megagen, Daegu, Republic of Korea) were placed in the tibiae of five rabbits using a conventional micromotor system (NSK group: SurgicPro+; NSK, Kanuma, Japan) and a diode laser-integrated micromotor system (SAESHIN group: BLP 10; Saeshin, Daegu, Republic of Korea). Resonance frequency analysis provided the implant stability quotient (ISQ) immediately after placement and at four weeks. Micro-computed tomography quantified the bone–implant interface gap (BIG). Removal torque was measured at sacrifice. Linear mixed-effects models with a random intercept for rabbit generated adjusted means with 95% confidence intervals (CIs) (α = 0.05). Equivalence for the four-week ISQ used two one-sided tests with a margin of ±5 ISQ. The SAESHIN group achieved a higher immediate ISQ than the NSK group (difference =+6.9 ISQ; 95% CI +1.3–+12.5; p = 0.018). At four weeks, the ISQ did not differ (difference = −1.2 ISQ; 95% CI −4.3–+1.9; p = 0.42), and equivalence was supported (TOST p_lower = 0.024; p_upper = 0.019). Removal torque was comparable (difference = +4.3 N·cm; 95% CI −5.2–+13.8; p = 0.36). BIG metrics showed no between-system differences across regions. ICC indicated clustering for ISQ and torque (0.36 and 0.31). The diode laser-integrated micromotor system yielded a higher immediate ISQ under a standardized 35 N·cm seating torque, whereas the ISQ, removal torque, and BIG at four weeks were comparable to those of the conventional system. The immediate ISQ should be interpreted as stiffness under fixed torque rather than superior device-dependent interlocking. These findings support the clinical interchangeability of the two systems for early osseointegration endpoints in preclinical settings. Full article

Background: Mandibular defects caused by trauma or tumor resection pose significant challenges in both functional and aesthetic reconstruction. Additive manufacturing (AM) technologies offer promising solutions for surgical planning and personalized treatment. Objectives: This review aims to evaluate current trends in the application of AM technologies for mandibular resection and reconstruction, with a particular focus on material selection, clinical integration, and technology-specific advantages. Methods: A structured literature review was performed using PubMed, Scopus, Web of Science, and Google Scholar. Studies published between January 2020 and May 2025 were screened using the following inclusion criteria: original peer-reviewed English-language research involving AM in mandibular surgery. The exclusion criteria included review articles, non-English sources, and non-mandibular studies. A total of 77 studies met the inclusion criteria and were analyzed in this review. Results: Based on the literature review conducted from 2020 to 2025, the most common restorative methods for the mandible using additively manufactured models include reconstruction with a titanium surgical plate bent to the curvature of the edges and angle of the mandible or a personalized titanium or PEEK surgical plate made directly based on the patient’s diagnosis. Implants made of Ti-6AL-4V ELI and bioceramic scaffolds are also used in the reconstruction process. They are developed based on patient diagnostic data and effectively replace the loss of mandibular bone structure. In addition, based on models and surgical guides created using additive manufacturing techniques, the performance of autogenous grafts from the fibula or iliac crest has improved significantly when used with a titanium implant plate. Conclusions: Additive manufacturing supports highly personalized and accurate mandibular reconstruction. The advantages of these methods include a reduced overall duration of procedures, a lower health risk for patients due to less reliance on general anesthesia, a near perfect match between the implant and the remaining hard tissues, and satisfactory aesthetic outcomes. However, success depends on the appropriate selection AM technology and material, particularly in load-bearing applications. Full article

Background: Immediate implant placement in the esthetic zone, particularly in Class II extraction sockets with partial facial bone loss, presents challenges in achieving soft and hard tissue stability. Customized computer-aided design/computer-aided manufacturing (CAD/CAM) titanium abutments may offer advantages over prefabricated stock abutments. This study compared the clinical, radiographic, and patient-reported outcomes of customized CAD/CAM titanium abutments versus stock Laser-Lok stock abutments. Materials and methods: In a single-center, double-blind randomized clinical trial, 48 patients received immediate maxillary anterior implants restored with either customized CAD/CAM titanium abutments (n = 24) or stock titanium abutments (n = 24). Primary outcomes included peri-implant probing depth (PD), mucosal height, Pink Esthetic Score (PES), crestal bone level changes, and patient satisfaction assessed at baseline, 6, and 12 months post-loading. Statistical analysis included effect sizes and 95% confidence intervals. Results: At 12 months, the customized abutment group showed significantly shallower PD (mean difference: −0.54 mm; 95% CI: −0.72 to −0.35; p < 0.001), higher PES (12.21 ± 0.35 vs. 10.41 ± 1.17; p < 0.0001; Cohen’s d = 2.08), and less crestal bone loss (1.75 ± 0.36 mm vs. 2.33 ± 0.52 mm; p < 0.0001). Patient satisfaction scores were also higher in the customized group (p = 0.003). Within-group improvements were observed in both groups over time. No implant failures occurred. Conclusions: At 1-year follow-up, customized CAD/CAM titanium abutments demonstrated improved peri-implant soft tissue parameters, esthetics, and patient satisfaction compared to stock abutments. While these findings support their use in esthetically demanding immediate implant cases, the short-term duration and single-center design warrant further long-term multicenter studies to confirm durability. Trial registration: Registered at ClinicalTrials.gov on 19/01/2025 (NCT06791655). Full article

The different macro and micro geometries of dental implants are parameters that directly affect osseointegration, making them an important area for research. The objective of this preclinical study was to compare, through histological and histomorphometric analyses, the biological response of two different dental implant surfaces in osseointegration. Surface morphology and chemistry were characterized by SEM/EDX, optical-emission spectroscopy, protein adsorption (BSA), and adipose-derived stem-cell morphology. For the in vivo arm, ten commercially pure titanium implants (n = 5 LS160 + 5 SBAE) were placed bilaterally in the tibiae of five skeletally mature New Zealand rabbits (one implant of each surface per animal). After six weeks, undecalcified sections were prepared and bone-to-implant contact (BIC) and bone-area-fraction occupancy (BAFO) were quantified histomorphometrically. Data normality was confirmed with the Shapiro–Wilk test; paired two-tailed Student’s t-tests were applied (α = 0.05). Results: The descriptive histological analysis showed a fraction of pre-existing bone in all experimental groups, which probably ensured primary stability. Adjacent to this area, it was possible to observe peri-implant newformed bone in all tested groups. The results of the histomorphometric analysis of BIC and BAFO were considered normal by the Shapiro–Wilk test (p > 0.05); after six weeks of implantation, the BIC values for the LS160 and SBAE groups were 44.13 (15.83–72.43) and 39.24 (10.72–89.21), respectively. The analysis of variance (ANOVA and Tukey’s post-test) showed no statistical differences between the groups tested. Likewise, the bone volume density showed no statistical differences between the groups (ANOVA and Tukey’s post-test) with averages of 41.27 (C.I. 24.00–58.55) and 26.52 (C.I. −17.51–70.54) in the LS160 and SBAE groups, respectively. Although both surfaces showed similar osseointegration after six weeks, the new surface appears to be a promising, eco-friendly alternative to SBAE. Future studies with shorter time points and larger samples are needed to assess early biological responses. Full article

Total ankle arthroplasty (TAA) has evolved significantly through advances in alloy selection and manufacturing technologies. This narrative review examines the metallurgical foundations of contemporary TAA implants, analyzing primary alloy systems and their mechanical properties. Cobalt-chromium alloys provide superior mechanical strength and durability but present metal ion release concerns, while titanium alloys (Ti6Al4V) optimize biocompatibility with elastic modulus values (101–113 GPa) closer to bone, despite tribological limitations. Novel β-titanium formulations (Ti-35Nb-7Zr-5Ta, Ti10Mo6Zr4Sn3Nb) eliminate toxic aluminum and vanadium components while achieving lower elastic modulus values (50–85 GPa) that better match cortical bone properties. Manufacturing has transitioned from traditional methods (investment casting, forging, CNC machining) toward additive manufacturing technologies. Selective laser melting and electron beam melting enable patient-specific geometries, controlled porosity, and optimized microstructures, though challenges remain with residual stresses, surface finish requirements, and post-processing needs. Emerging biodegradable materials, composite structures, and hybrid implant designs represent promising future directions for addressing current material limitations. This review provides evidence-based insights for alloy selection and manufacturing approaches, emphasizing the critical role of materials engineering in TAA implant performance and clinical outcomes. Full article

Background/Objectives: Anterior cervical discectomy and fusion (ACDF) is a common procedure for treating cervical spondylotic myelopathy. Limited research exists on the predictors of subsidence following ACDF. Subsidence can compromise surgical outcomes, alter alignment, and predispose patients to further complications, making it essential to prevent and understand it. This study aims to identify key risk factors for clinically significant subsidence and evaluate its impact on cervical alignment parameters in a large, diverse patient population. Methods: We conducted a retrospective review of patients who underwent ACDF between 2013 and 2022 at a single institution. Subsidence was calculated as the mean change in anterior and posterior disc height, with clinically significant subsidence being defined as three millimeters or more. Univariate analysis was followed by regression modeling to identify subsidence predictors and analyze patterns. Subgroup analyses stratified patients by implant type, number of levels fused, and cage material. Results: A total of 96 patients with 141 levels of ACDF met the inclusion criteria. Patients with significant subsidence were younger on average (52.44 vs. 55.94 years; p = 0.074). Those with less postoperative lordosis were more likely to experience significant subsidence (79.5% vs. 90.2%; p = 0.088). Patients with significant subsidence were more likely to have standalone implants (38.5% vs. 16.7%; p < 0.01), taller cages (6.62 mm vs. 6.18 mm; p < 0.05), and greater loss of segmental lordosis (7.33 degrees vs. 3.31 degrees; p < 0.01). Multivariate analysis confirmed that standalone implants were a significant independent predictor of subsidence (OR 2.679; p < 0.05), and greater subsidence was positively associated with loss of segmental lordosis (OR 1.089; p < 0.01). Subgroup analysis revealed that multi-level procedures had a higher incidence of subsidence (35.7% vs. 28.1%; p = 0.156), and PEEK cages demonstrated similar subsidence rates compared to titanium constructs (28.1% vs. 29.4%; p = 0.897). Conclusions: Standalone implants are the strongest independent predictor of significant subsidence, and those that experience subsidence also show greater loss of segmental lordosis, although not overall lordosis. These findings have implications for surgical planning, particularly in patients with borderline bone quality or requiring multi-level fusions. The results support the use of plated constructs in high-risk patients and emphasize the importance of individualized surgical planning based on patient-specific factors. Further research is needed to explore these findings and determine how they can be applied to improve ACDF outcomes. Full article

Background: The long-term success of total knee arthroplasty (TKA) is often compromised by stress shielding, which can lead to bone resorption and even implant loosening. This study employs finite element analysis (FEA) to compare the stress-shielding effects of a knee prosthesis made from polyether ether ketone (PEEK) with a traditional titanium Ti6Al4V implant on an osteoporotic tibial bone model. Methods: Stress distribution and the stress-shielding factor (SSF) were evaluated at seven critical points in the proximal tibia under physiological loading conditions. Results: Results indicate that the PEEK prosthesis yields a more uniform stress transmission, with von Mises stress levels within the optimal 2–3 MPa range for bone maintenance and consistently negative or near-zero SSF values, implying minimal stress shielding. Conversely, titanium implants exhibited significant stress shielding with high positive SSF values across all points. Additionally, stress concentrations on the polyethylene liner were lower and more evenly distributed in the PEEK model, suggesting reduced wear potential. Conclusions: These findings highlight the biomechanical advantages of PEEK in reducing stress shielding and preserving bone integrity, supporting its potential use to improve implant longevity in TKA. Further experimental and clinical validation are warranted. Full article

Titanium–aluminum–vanadium (Ti6Al4V) is a material chosen for spine, orthopedic, and dental implants due to its combination of desirable mechanical and biological properties. Lasers have been used to modify metal surfaces, enabling the generation of a surface on Ti6Al4V with distinct micro- and nano-scale structures. Studies indicate that topography with micro/nano features of osteoclast resorption pits causes bone marrow stromal cells (MSCs) and osteoprogenitor cells to favor differentiation into an osteoblastic phenotype. This study examined whether the biological response of human MSCs to Ti6Al4V surfaces is sensitive to laser treatment-controlled micro/nano-topography. First, 15 mm diameter Ti6Al4V discs (Spine Wave Inc., Shelton, CT, USA) were either machined (M) or additively manufactured (AM). Surface treatments included no laser treatment (NT), nanosecond laser (Ns), femtosecond laser (Fs), or nanosecond followed by femtosecond laser (Ns+Fs). Surface wettability, roughness, and surface chemistry were determined using sessile drop contact angle, laser confocal microscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Human MSCs were cultured in growth media on tissue culture polystyrene (TCPS) or test surfaces. On day 7, the levels of osteocalcin (OCN), osteopontin (OPN), osteoprotegerin (OPG), and vascular endothelial growth factor 165 (VEGF) in the conditioned media were measured. M NT, Fs, and Ns+Fs surfaces were hydrophilic; Ns was hydrophobic. AM NT and Fs surfaces were hydrophilic; AM Ns and Ns+Fs were hydrophobic. Roughness (Sa and Sz) increased after Ns and Ns+Fs treatment for both M and AM disks. All surfaces primarily consisted of oxygen, titanium, and carbon; Fs had increased levels of aluminum for both M and AM. SEM images showed that M NT discs had a smooth surface, whereas AM surfaces appeared rough at a higher magnification. Fs surfaces had a similar morphology to their respective NT disc at low magnification, but higher magnification revealed nano-scale bumps not seen on NT surfaces. AM Fs surfaces also had regular interval ridges that were not seen on non-femto laser-ablated surfaces. Surface roughness was increased on M and AM Ns and Ns+Fs disks compared to NT and Fs disks. OCN was enhanced, and DNA was reduced on Ns and Ns+Fs, with no difference between them. OPN, OPG, and VEGF levels for laser-treated M surfaces were unchanged compared to NT, apart from an increase in OPG on Fs. MSCs grown on AM Ns and Ns+Fs surfaces had increased levels of OCN per DNA. These results indicate that MSCs cultured on AM Ns and AM Ns+Fs surfaces, which exhibited unique roughness at the microscale and nanoscale, had enhanced differentiation to an osteoblastic phenotype. The laser treatments of the surface mediated this enhancement of MSC differentiation and warrant further clinical investigation. Full article

Background/Objectives: Tamoxifen, a selective estrogen receptor modulator widely used as an adjunct in the treatment of breast cancer, has known effects on bone metabolism, although its impact on osseointegration and cellular responses during early bone healing remains unclear. Understanding these effects is essential given the increasing use of dental implants in cancer survivors. The study aimed to observe the influence of tamoxifen on human osteosarcoma (SAOS-2) cells lines, as well on the osseointegration of titanium implants in ovariectomized female rats. Methods: SAOS-2 cells were incubated with Dulbecco’s modified growth medium. Six titanium (Ti) disks were used at each time point. The samples were divided into groups with the presence (TAM, n = 36) or not (CTR, n = 36) of tamoxifen in a concentration of 2 μM. In vivo, 72 animals were divided in groups with bilateral ovariectomy or SHAM and tamoxifen administration or not (15 mg/kg). Cell viability, mineralization rate, and collagen synthesis were assessed, as well as bone/implant contact (BIC) and bone ingrowth (BIN). Results: Tamoxifen caused a decrease in SAOS-2 viability, although an increase in the mineralization rate was observed. In vivo, the TAM groups presented higher BIC and BIN when compared to their control, but a lower percentage of mature collagen cells. Conclusions: Based on our findings, in vitro, the therapy with TAM slightly reduced the viability of SAOS-2 cells while significantly increasing the mineralization rate. In vivo, the therapy positively influenced BIC and BIN during the osseointegration phase. Full article

The thermo-chemical treatment of dental implants leads to the formation of sodium titanate crystals on their surface. When in contact with blood, these crystals dissolve and trigger an ionic exchange cascade, resulting in the formation of a calcium apatite layer. This study, carried out both in vitro and in an animal model, aimed to determine whether the cooling rate of the treatment affects the size of the deposited crystals, and whether this in turn influences wettability and early bone-to-implant contact (BIC). A total of 50 dental implants and 50 titanium discs were treated using four different cooling rates, along with a control group. Crystal size was analyzed on implant surfaces using scanning electron microscopy, and wettability was assessed on titanium discs using a goniometer. Finally, the implants were placed in the tibiae of 13 rabbits, and histological analysis was performed after three weeks to compare BIC among groups. Results suggest that a cooling rate of 75 °C/h produces smaller sodium titanate crystals, which are associated with significantly improved surface wettability and a higher percentage of bone-to-implant contact after 3 weeks of healing (p < 0.05). Full article

Background/Objectives: Dental practitioners widely use dental implants to treat traumatic cases. Titanium implants are currently the most popular choice among dental practitioners and surgeons. The discovery of newer polymeric materials is also influencing the interest of dental professionals in alternative options. A comparative study between existing titanium implants and newer polymeric materials can enhance professionals’ ability to select the most suitable implant for a patient’s treatment. This study aimed to investigate material property advantages of high-performance thermoplastic biopolymers such as PEEK and PEKK, as compared to the time-tested titanium implants, and to find the most suitable and economically fit implant material. Methods: Three distinct implant material properties were assigned—PEEK, PEKK, and commercially pure titanium (CP Ti-55)—to dental implants measuring 5.5 mm by 9 mm, along with two distinct titanium (TI6AL4V) abutments. Twelve three-dimensional (3D) models of bone blocks, representing the mandibular right molar area with Osseo-integrated implants were created. The implant, abutment, and screw were assumed to be linear; elastic, isotropic, and orthotropic properties were attributed to the cancellous and cortical bone. Twelve model sets underwent a three-dimensional finite element analysis to evaluate von Mises stress and total deformation under 250 N vertical and oblique (30 degree) loads on the top surface of each abutment. Results: The study revealed that the time-tested titanium implant outperforms PEEK and PEKK in terms of marginal bone preservation, while PEEK outperforms PEKK. Conclusions: This study will assist dental practitioners in selecting implants from a variety of available materials and will aid researchers in their future research. Full article

Background: The role of collagen membrane fixation during guided bone regeneration (GBR) remains debatable, particularly in post-extraction sockets with buccal defects and concomitant immediate implant placement. This study evaluated whether or not fixation with titanium pins improved regenerative outcomes. Methods: Six adult Beagle dogs received bilateral extractions of the fourth mandibular premolars. An implant was immediately placed in both the distal alveoli, and standardized buccal bone defects (5 mm height, 3–2 mm width) were prepared. All defects were filled with a slowly resorbing equine xenograft and covered by a resorbable pericardium membrane. At the test sites, the membrane was apically fixed with pins, while no fixation was applied to the control sites. After 3 months of healing, histomorphometric analyses were performed. Results: The vertical bone gain of the buccal crest was 3.2 mm in the test sites (pin group) and 2.9 mm in the control sites (no-pin) (p > 0.754). No significant difference was found in terms of bone-to-implant contact (BIC). However, residual graft particles were located significantly more coronally in the pin group compared to the no-pin group (p = 0.021). Morphometric analyses revealed similar new bone formation within the groups, but with higher amounts of residual xenograft and soft tissue in the pin group. Conclusions: Membrane fixation did not significantly enhance vertical bone gain, and although the slightly higher regeneration in the pin group (3.2 mm vs. 2.9 mm) may hold clinical relevance in esthetically sensitive areas and osseointegration, it appeared to limit apical migration of the grafting material. Full article

Enhancing osseointegration is a common goal for many titanium implant coatings, since the naturally forming oxides are often bioinert and exhibit less than ideal bone-to-implant contact. Oxide coating surface topographies, chemistries, and crystallinities are known to play key roles in enhancing bone–implant interactions. In the present study, two novel anodization processes were developed in electrolytes based on juiced navel oranges to create bioactive oxide coatings on commercially pure titanium (CPTi) surfaces. Both oxide groups revealed multi-scaled micro and nano surface topographies, significant Ca and P-dopant incorporation exhibiting Ca/P ratios similar to human bone (1.7 and 1.8), and physiologically relevant Mg uptake levels of <0.1% and 1.4 at%. XRD and FTIR analyses of each oxide revealed a combination of tricalcium phosphate and hydroxyapatite phases that showed carbonate substitutions indicative of bone-like apatite formation. Finally, VDI indentation testing revealed good adhesion strengths, minimal cracking, and no visible delamination for both oxides. In summary, the anodization processes in the present study were shown to produce carbonated tricalcium phosphate and apatite containing oxides with contrasting levels of Mg uptake that show much promise to improve future implant clinical outcomes. Full article

Porosity and roughened surfaces of implant materials have been shown to lead to improved cellular attachment and enhanced osseointegration. These topography changes in the surface also aid in the mechanical interlocking of the material to the bone. Polyetheretherketone (PEEK) has emerged as a popular alternative to titanium-based implants due to its lack of stress-shielding effect, radiolucency, and high chemical resistance. However, PEEK is bioinert, thus requiring surface modifications to elicit appropriate cellular responses that lead to successful osteointegration of the material in vivo. Sulfonation is a process used to modify the surface of PEEK, which can be controlled by varying parameters such as soak time and soak temperature, thereby fabricating a porous surface on the material. This work aimed to ensure the repeatability of a previously optimized sulfonated and hydrothermally treated PEEK surface and subsequently observe the mechanical properties, bacterial attachment, and cellular response of pre-osteoblast MC3T3-E1 cells on the surface. This study found that while all PEEK surfaces had similar cell and Staphylococcus aureus attachment, the sulfonated and hydrothermally treated PEEK (peak mean load of 605 N, p ≤ 0.0001) and the sulfonated only PEEK (peak mean load of 495 N, p = 0.0240) had a higher level of performance in expulsion testing than smooth PEEK due to its mechanical interlocking ability. Imaging and contact angle analysis confirm that a surface with repeatable porosity can be achieved. Full article

This study evaluated the effects of low-dose recombinant human bone morphogenetic protein-2 (rhBMP-2) coating in combination with vacuum plasma treatment on titanium implants, aiming to enhance osseointegration and bone regeneration while minimizing the adverse effects associated with high-dose rhBMP-2. In vitro analyses demonstrated that plasma treatment increased surface energy, promoting cell adhesion and proliferation. Additionally, it facilitated sustained rhBMP-2 release by enhancing protein binding to the implant surface. In vivo experiments using the four-beagle mandibular defect model were conducted with the following four groups: un-treated implants, rhBMP-2–coated implants, plasma-treated implants, and implants treated with both rhBMP-2 and plasma. Micro-computed tomography (micro-CT) and medical CT analyses revealed a significantly greater volume of newly formed bone in the combined treatment group (p < 0.05). Histological evaluation further confirmed superior outcomes in the combined group, showing significantly higher bone-to-implant contact (BIC), new bone area (NBA), and inter-thread bone density (ITBD) compared to the other groups (p < 0.05). These findings indicate that vacuum plasma treatment enhances the biological efficacy of low-dose rhBMP-2, representing a promising strategy to improve implant integration in compromised conditions. Further studies are warranted to determine the optimal clinical dosage. Full article