Search Results (57)

CAD/CAM polymer-based dental materials are increasingly used as metal-free alternatives for fixed and implant-supported restorations. High-performance polymers such as polyetheretherketone (PEEK), fiber-reinforced composites, and graphene-reinforced polymers have been introduced to improve material stability; however, evidence regarding the effects of thermal aging on their physicochemical and biological properties remains limited. In this study, PEEK, a fiber-reinforced composite (FRC), and a graphene-reinforced PMMA-based polymer (G-CAM) were evaluated. Twenty-seven disc-shaped specimens (10 × 2 mm; n = 9 per material) were fabricated and subjected to 10,000 thermal cycles between 5 and 55 °C. Color change (ΔE₀₀), surface roughness (Ra), and Vickers microhardness (VHN) were measured before and after aging. Chemical stability was assessed using FTIR and Raman spectroscopy, surface morphology by SEM analysis, and biological safety by cytotoxicity testing. Material-dependent differences were observed in color stability, surface roughness, and microhardness after thermal aging (p < 0.05). Microhardness decreased in the fiber-reinforced and graphene-reinforced materials, whereas PEEK showed no significant change. Spectroscopic analyses indicated preserved chemical structure, and all materials demonstrated acceptable cytocompatibility. Thermal aging influenced material behavior while chemical stability and biological safety were maintained, highlighting the importance of considering aging behavior during material selection for prosthetic restorations. Full article

Maxillofacial skeletal reconstruction presents significant challenges due to anatomical complexity, functional requirements, and aesthetic demands. Traditional materials such as titanium and autogenous bone grafts have limitations, prompting interest in Polyetheretherketone (PEEK), a versatile thermoplastic polymer with advantages like biocompatibility, radiolucency, and elasticity similar to human bone. This multi-year case series evaluates the clinical outcomes of PEEK implants used in 56 cases on 53 patients for maxillofacial reconstruction, primarily for trauma (44 patients) and deformity (9 patients). PEEK implants were applied to various facial regions including the orbit, zygoma, mandible, and maxilla. The majority of surgeries utilised virtual surgical planning. Patient-specific implants were fabricated using 3D imaging technologies, allowing customisation for optimal fit and functionality. The mean patient age was 37 years with a split of 37 to 16 females. Some complications were noted such as infection and paraesthesia. However, the majority of patients experienced positive outcomes. The findings support PEEK implants as a safe, effective, and adaptable material for maxillofacial surgery, with potential for further advancements in material properties and surgical technologies to improve long-term outcomes. Full article

The restoration of endodontically treated teeth remains a clinical challenge, particularly when substantial coronal tissue loss is present. Endocrowns fabricated using CAD/CAM technologies offer a conservative and esthetic alternative to conventional post-core systems; however, their long-term performance may be influenced by age-related mechanical and thermal stresses. This study evaluated the effect of thermomechanical aging on the marginal adaptation and fracture resistance of endocrowns fabricated from three CAD/CAM materials: zirconia-reinforced lithium silicate (ZLS), polyetherether ketone (PEEK), and 3D-printed resin. Sixty extracted human molars were endodontically treated and restored with endocrowns produced from these materials (n = 20 per group) and then subdivided into aged (n = 10) and control (n = 10) subgroups. Thermomechanical aging involved 5000 thermal cycles between 5 °C and 55 °C, and 75,000 mechanical loading cycles at 50 N. Marginal gaps were examined using scanning electron microscopy, and fracture resistance was tested under axial load at a crosshead speed of 0.5 mm/min. Data were analyzed using two-way ANOVA followed by Tukey’s post hoc test (α = 0.05). Thermomechanical aging significantly increased the marginal gaps in all materials (p < 0.05). The smallest marginal discrepancies were observed in the 3D-printed resin group, while the largest occurred in the ZLS after aging, likely due to dimensional changes during crystallization. Fracture resistance decreased in ZLS (−21.2%) and 3D resin (−20.9%) after aging (p < 0.05) but was not significantly affected in PEEK (−5.4%, p = 0.092). Thermomechanical aging adversely affects marginal adaptation across all materials, whereas its impact on strength is material-dependent. PEEK demonstrated the most stable mechanical performance and may represent a promising alternative for long-term endocrown restorations. Full article

This narrative review examines contemporary applications of polymeric materials in dentistry from 2020 to 2025, spanning prosthodontics, restorative dentistry, orthodontics, endodontics, implantology, diagnostics, and emerging technologies. We searched PubMed, Scopus, Web of Science, and Embase for peer reviewed English language articles and synthesized evidence on polymer classes, processing routes, mechanical and chemical behavior, and clinical performance. Approximately 116 articles were included. Polymers remain central to clinical practice: poly methyl methacrylate (PMMA) is still widely used for dentures, high performance systems such as polyether ether ketone (PEEK) are expanding framework and implant-related indications, and resin composites and adhesives continue to evolve through nanofillers and bioactive formulations aimed at improved durability and reduced secondary caries. Thermoplastic polyurethane and copolyester systems drive clear aligner therapy, while polymer-based obturation materials and fiber-reinforced posts support endodontic rehabilitation. Additive manufacturing and computer aided design computer aided manufacturing (CAD CAM) enable customized prostheses and surgical guides, and sustainability trends are accelerating interest in biodegradable or recyclable dental polymers. Across domains, evidence remains heterogeneous and clinical translation depends on balancing strength, esthetics, biocompatibility, aging behavior, and workflow constraints. Full article

Background/Objectives: Pediatric orbital tumors are rare and complex, requiring multidisciplinary care at specialized centers. Contemporary treatment paradigms emphasize centralized care delivery through experienced multidisciplinary teams to optimize patient outcomes. Recent advances in surgical planning technologies and intraoperative navigation systems have substantially enhanced surgical safety through improvement in tumor resection and reconstruction and reduction in complications, including recurrence of the lesion. Computed-aided surgical technologies enable precise virtual planning, minimally invasive approaches and more precise reconstruction methods when necessary by mean of patient-specific cutting guides, premolded orbital plates or individual patient solutions (IPS) prosthesis. Three-dimensional biomodelling visualizes tumor architecture and aids localization while preserving neurovascular structures, and real-time neuronavigation improves safety and efficacy. Methods: We conducted a retrospective analysis of 98 pediatric patients with orbital tumors treated between 2014 and 2025 at a tertiary center to evaluate the use of computed-assisted surgical technologies and the indications for treatment. Inclusion criteria comprised all cases where computer-assisted techniques were employed. Patients were classified into two groups: Group 1—intraconal or extensive periorbital lesions with eye-sparing intent treated via craniofacial approaches; Group 2—periorbital tumors with orbital wall involvement, to analyze the use of the different technologies. Data collected included tumor age, type, location, technology used, adjunctive treatments, and postoperative outcomes. Results: Twelve patients underwent computer-assisted surgery. Technologies employed over the last six years included intraoperative navigation, 3D planning with/without tumor segmentation, orbital-wall reconstruction by mirroring, IPS or titanium mesh bending, and preoperative biomodelling. Patients were grouped by tumor location and treatment goals: Group 1—intraorbital lesions (primarily intraconal or 270–360° involvement), including one case of orbital encephalocele treated transcranially; Group 2—periorbital tumors with orbital-wall destruction, treated mainly via midfacial approaches. Intraoperative navigation was used in 10/12 cases (8/11 with tumor segmentation); in 3 cases with ill-defined margins, navigation localized residual tumor. Virtual surgery predominated in Group 2 (4 patients) and one in Group 1, combined with cutting guides for margins and Individual Prosthetic Solutions (IPS) prosthesis fitting (two patients: titanium and PEEK). In two cases, virtual plans were performed, STL models printed, and premolded titanium meshes used. No complications related to tumor persistence or orbital disturbance were observed. Conclusions: Advanced surgical technologies substantially enhance safety, efficiency, and outcomes in pediatric orbital tumors. Technology-assisted approaches represent a paradigm shift in this complex field. Additional studies are needed to establish evidence-based protocols for systematic integration of technology in pediatric orbital tumor management. Full article

The purpose of this study was to evaluate the effect of different framework materials and thermal aging on the shear bond strength (SBS) of gingiva-colored composites used in fixed dental restorations. A total of 270 samples (10 × 10 × 2 mm³) were prepared using titanium, zirconia, and modified polyetheretherketone (modified PEEK). Three gingiva-colored composites (Gradia Gum, Anaxgum, Nexco) were applied after surface polishing and sandblasting. All specimens were stored in water at 37 °C for 24 h, then half of each group was subjected to thermal aging consisting of 10,000 cycles at temperatures between 5 and 55 °C. SBS testing was performed using a universal testing machine with a crosshead speed of 1 mm/min. Bonding failures were analyzed under a stereomicroscope, and one sample from each group was examined using a scanning electron microscope. SBS data were analyzed using three-way ANOVA with composite type, framework material, and thermal aging as factors, followed by pairwise comparisons (SPSS 23.0; p < 0.05). The highest SBS was recorded for the zirconia framework combined with Gradia Gum, specifically in the group without thermal aging (p < 0.05), while the lowest was observed for zirconia combined with Nexco after thermal aging (p < 0.05). Adhesive failures were predominant in the modified PEEK groups, whereas mixed failures occurred more frequently in titanium and zirconia groups. Both composite type and framework material significantly influenced SBS values, with thermal aging having a detrimental effect across all groups. This study demonstrates that both framework material and composite type affect bond strength, with specimens not subjected to thermal aging maintaining better adhesion. Thermal cycling reduced SBS in all groups, although the extent varied by material combination. Full article

This study analyzes the biomechanical performance of intramedullary nails made of titanium alloy (Ti-6Al-4V) and carbon fiber-reinforced polyetheretherketone (CFR-PEEK) for the treatment of proximal femoral fractures, with a focus on their effects under different bone density conditions representing young and osteoporotic bone. Using finite element models and analyses simulating mid-stance gait loading and incorporating muscle forces adjusted for age-related reduction, the load transfer and stress distribution were evaluated, along with the osteogenic index (OI) as a measure of biological stimulus for bone healing. Results showed that titanium nails produced lower bone stresses but caused significant proximal stress shielding, particularly in osteoporotic bone, which could impair healing. In contrast, CFR-PEEK nails exhibited higher and more uniformly distributed stresses along the femoral diaphysis and shifted the osteogenic stimulus into a range promoting more mature bone formation in both young and elderly femora. The composite material’s elastic modulus closer to bone and its orthotropic fiber arrangement contributed to these effects. The study concludes that CFR-PEEK nails offer a promising alternative to titanium by reducing stress shielding and enhancing the biomechanical environment favorable for fracture healing, especially in osteoporotic patients. Future work will include dynamic loading conditions and experimental validation to optimize implant design. Full article

In the pursuit of addressing the persistent challenge of bacterial adhesion and biofilm formation in dental care, this study investigates the efficacy of electric current as an alternative strategy, specifically focusing on its application in dental contexts. Polyether ether ketone (PEEK), known for its excellent biocompatibility and resistance to bacterial plaque, was enhanced with conductive properties by incorporating silver (Ag), a well-known antibacterial material. Through systematic in vitro experiments, the effectiveness of alternating current (AC) and direct current (DC) in reducing bacterial proliferation was evaluated. The tests were conducted using two bacterial strains: the Gram-positive Staphylococcus aureus and the Gram-negative Pseudomonas aeruginosa. Various configurations, current parameters, and two different electrode configurations were assessed to determine their impact on bacterial reduction. A notable finding from this study is that alternating current (AC) demonstrates superior efficacy compared to direct current (DC). The more significant decrease in CFUs/mL for P. aeruginosa with AC was recorded at the current levels of 5 mA and 500 nA. In opposition, S. aureus exhibited the greatest reduction at 5 mA and 1 mA. This study highlights the potential of using electric current within specific intensity ranges as an alternative strategy to effectively mitigate bacterial challenges in dental care. Full article

Background: Carbon-fiber-reinforced polyetheretherketone (CFR-PEEK) vertebral-body replacements (VBRs) aim to mitigate subsidence, minimize imaging artifacts, and facilitate radiation planning while preserving fusion potential. We assessed the safety and efficacy of a novel modular, titanium-coated CFR-PEEK VBR (Kong^®) for anterior column reconstruction (ACR) in the thoracolumbar spine. Primary question: Does the implant safely and effectively achieve and maintain kyphosis correction after ACR for trauma and neoplasms? Methods: A single-center retrospective case series was performed on 28 patients who underwent thoracolumbar ACR with the Kong^® VBR for fractures or tumors (2020–2021). The primary outcome was the bi-segmental kyphotic angle (BKA). Secondary outcomes were screw loosening, cage height loss, fusion rate, subsidence, and tilting. Clinical status was recorded with Odom criteria, Karnofsky Performance Status (KPS), and AOSpine PROST. Results: Twenty-eight patients (mean age, 61 yr; 33% female; mean follow-up, 17.7 mts) were studied. Mean postoperative BKA correction was 16.5° (p = 0.006) and remained 14.5° at final follow-up (p = 0.008); loss of correction was 2.0° (p = 0.568). Subsidence, cage height, and sagittal tilt were unchanged. Fusion (Bridwell grade I/II) was observed in 95% on CT. One deep surgical-site infection occurred. At final follow-up, 91% of patients were graded “excellent” or “good” by Odom. KPS improved by 20 points (p = 0.031), and mean AOSpine PROST was 56.9. Conclusions: Single-center early results indicate that the modular titanium-coated CFR-PEEK VBR is a safe, effective adjunct for thoracolumbar ACR in trauma and neoplasm, providing durable kyphosis correction, mechanical stability and high fusion rates and grants for improved follow-up imaging quality. Full article

Background/Objectives: The dental industry is continuously developing high-performance polymer (HPP) materials with different qualities for denture frameworks. The aim of this in vitro study was to assess how thermal ageing (TA) affects the flexural strength (FS) and microhardness of two different HPP materials: Nanoksa G-plus and Bio-HPP/PEEK. Methods: The TA process was carried out for 5000 cycles at 5 °C and 55 °C in distilled water. To assess FS, a total of 40 bar-shaped specimens measuring 65.0 mm × 10.0 mm × 2.5 mm (20 per group) were obtained; TA and No-TA (NTA) subgroups were prepared for each material group (10 per subgroup); and a three-point bending test was conducted using an Instron universal testing machine. Each specimen that fractured during the FS test was subjected to microhardness measurement using a Vickers hardness tester. The mean FS and microhardness of the TA and NTA specimens were statistically examined using the t-test. Results: Both the TA and NTA Bio-HPP/PEEK specimens exhibited significantly greater (p < 0.0001) microhardness and FS qualities than the Nanoksa G-Plus specimens. The FS and microhardness of the Bio-HPP/PEEK and Nanoksa G-Plus materials significantly decreased (p < 0.05) after TA. Conclusions: The Bio-HPP/PEEK material showed better FS and microhardness properties than the Nanoksa G-Plus material. TA considerably decreased the FS and microhardness of the Bio-HPP/PEEK and Nanoksa G-Plus materials. Full article

Background: There are very few studies in literature concerning the bonding between 3D-printed resin posts and the core build-up material. This study aimed to evaluate and compare the adhesion of 3D-printed and milled resin posts to composite resin core build-up material following different surface treatments. Methods: Three types of resin posts were utilized in this study: ready-made glass-reinforced fiber post (3M ESPE, Germany), milled PEEK POST (Bredent, Germany), and 3D-printed resin post (CROWNTEC, Saremco Dental AG, Switzerland). Each type of post was categorized into three groups based on surface treatments: C: untreated surfaces; SB: Air abrasion with 50 μm aluminum oxide particles was applied to the posts’ surfaces.; HO: the posts’ surfaces were immersed in 30% H₂O₂ for 5 min. A dual-cured composite resin (Grandio DC; VOCO) was utilized for core build-up in each group to evaluate adhesion through the push-out bond strength test. The modes of failure were analyzed, and the surface morphology of the post was characterized using SEM. Data were analyzed using a two-way analysis of variance (ANOVA) along with Tukey’s test. Results: The two-way ANOVA indicated a significant effect for surface treatment (F = 583.54, p < 001), post type (F = 79.96, p < 0.001), and their interactions (F = 265.74, p < 0.001). Regarding 3D-printed resin post, 30% H₂O₂ for 5 min recorded the highest statistically significant bond strength value (13.11 ± 1.61) compared to other groups. Regarding the milled PEEK post, the air particle abrasion recorded the highest statistically significant value (23.88 ± 1.66) compared to other groups. Adhesive failure was the predominant failure type, with an occurrence rate of 70.35%. Mixed failure was noted in 24.07% of the cases, with a significant prevalence in the PEEK post within the air particle abrasion group (58.3%). Cohesive failure was noted in 5.54% of cases, with a significant prevalence in the air particle abrasion group, occurring at rates of 16.6% in the resin fiber post group and 33.3% in PEEK posts. Conclusions: Air particle abrasion significantly improved the push-out bond strength of milled PEEK posts, but it did not have a similar effect on the 3D-printed resin posts. The application of 30% H₂O₂ for 5 min to 3D-printed resin post enhanced the adhesion to core build-up material. The manufacturing method of posts, the surface treatments utilized, and their interactions affect the interfacial bond strength between posts and the composite resin core build-up material. Full article

Background: This study evaluated and compared the effects of thermal aging on the color stability and mechanical properties of CAD/CAM polymers utilized for provisional restorations. Material and Methods: Three CAD/CAM polymers in this study: CAD-Temp (CAT), Everest C-Temp (CT), and PEEK (PK). Forty specimens of each material were randomly assigned to two subgroups. Subgroup A was immersed in distilled water for 24 h, whereas Subgroup B was subjected to 5000 thermal cycles. The color stability, flexural strength (FS), survival probability, and microstructures were evaluated following thermal cycling. Data analysis was conducted utilizing two-way ANOVA along with Tukey’s test. Results: The CAT (3.74 ± 0.39) and CT (3.51 ± 0.54) groups exhibited the highest color variations, while PEEK (2.95 ± 0.45) showed the lowest color change. The baseline groups showed that the CT group had the highest flexural strength value (p < 0.05). The flexural strength values of CAT and CT groups significantly decreased (p < 0.05) following thermal cycling. No significant decrease in FS was observed following thermal cycling in the Pk group (p = 0.16). Conclusions: The color measurement and flexural strength outcomes were significantly influenced by CAD/CAM materials and thermal cycling. The CT group demonstrated superior flexural strength compared to the other groups, both before and after thermal cycling. The PK group shows the lowest color change compared to other groups. Regardless of aging condition, C-Temp and PEEK materials recorded the highest survival probability, a 95% significance level compared to CAD-Temp. Full article

The increasing demand for orthopedic and neurosurgical implants has driven advancements in biomaterials, additive manufacturing, and antimicrobial strategies. With an increasingly aging population, and a high incidence of orthopedic trauma in developing countries, the need for effective, biocompatible, and infection-resistant implants is more critical than ever. This review explores the role of polymers in 3D printing for medical applications, focusing on their use in orthopedic and neurosurgical implants. Polylactic acid (PLA), polycaprolactone (PCL), and polyetheretherketone (PEEK) have gained attention due to their biocompatibility, mechanical properties, and potential for antimicrobial modifications. A major challenge in implantology is the risk of periprosthetic joint infections (PJI) and surgical site infections (SSI). Current strategies, such as antibiotic-loaded polymethylmethacrylate (PMMA) spacers and bioactive coatings, aim to reduce infection rates, but limitations remain. Additive manufacturing enables the creation of customized implants with tailored porosity for enhanced osseointegration while allowing for the incorporation of antimicrobial agents. Future perspectives include the integration of artificial intelligence for implant design, nanotechnology for smart coatings, and bioresorbable scaffolds for improved bone regeneration. Advancing these technologies will lead to more efficient, cost-effective, and patient-specific solutions, ultimately reducing infection rates and improving long-term clinical outcomes. Full article

Polyaryletherketone (PAEK) materials, including polyetheretherketone (PEEK) and polyetherketoneketone (PEKK), possess excellent mechanical properties and biocompatibility; however, their inherently low surface energy limits effective bonding with resin cements. This study investigated the effects of hydrofluoric acid (HF) etching and handheld nonthermal plasma (HNP) treatment on enhancing the adhesive performance of PAEK surfaces. Disk-shaped PEEK (BP) and PEKK (PK) specimens were divided into four groups: APA (airborne-particle abrasion), PLA (nonthermal plasma treatment), LHF (5.0% HF), and HHF (9.5% HF). Surface characterization was performed using a thermal field emission scanning electron microscope (FE-SEM). Surface wettability was evaluated using contact angle goniometry. Cytotoxicity was evaluated using HGF-1 cells exposed to conditioned media and analyzed via PrestoBlue assays. Shear bond strength (SBS) was measured after three aging conditions—NT (no aging), TC (thermocycling), and HA (highly accelerated aging)—using a light-curing resin cement. Failure modes were categorized, and statistical analysis was performed using one-way and two-way ANOVA with Tukey’s HSD test (α = 0.05). Different surface treatments did not affect surface characterization. PLA treatment significantly improved surface wettability, resulting in the lowest contact angles among all groups, followed by HF etching (HHF > LHF), while APA showed the poorest hydrophilicity. Across all treatments, PK exhibited better wettability than BP. Cytotoxicity results confirmed that all surface treatments were nontoxic to HGF-1 cells, indicating favorable biocompatibility. SBS testing demonstrated that PLA-treated specimens achieved the highest and most stable bond strength across all aging conditions. Although HF-treated groups exhibited lower bond strength overall, BP samples treated with HF showed relatively less reduction following aging. Failure mode analysis revealed a shift from mixture and cohesive failures in the NT aging condition to predominantly adhesive failures after TC and HA aging conditions. Notably, the PLA-treated groups retained mixture failure patterns even after aging, suggesting improved interfacial durability. Among the tested methods, PLA treatment was the most effective strategy, enhancing surface wettability, bond strength, and aging resistance without compromising biocompatibility. In summary, the PLA demonstrated the greatest clinical potential for improving the adhesive performance of PAEK when used with light-curing resin cements. Full article

Owing to its superior mechanical properties and recyclability, the carbon fabric/polyetheretherketone (CFF/PEEK) composite has seen increasing application in engineering domains. However, studies examining the impact of hygrothermal aging on its performance remain relatively limited in the existing literature. To investigate its durability in hygrothermal environments, this study fabricated CFF/PEEK composites with a fiber volume fraction of 55 vol% and subjected them to equilibrium hygroscopic treatment at 70 °C. The hygroscopic behavior of polyetheretherketone (PEEK) resin and CFF/PEEK composites, along with their tensile and compressive properties under dry conditions at room temperature (RTD) and wet conditions at 70 °C (ETW), were systematically evaluated. The results indicated that both PEEK resin and CFF/PEEK composites exhibited Fickian diffusion behavior during the initial stages of aging but diverged in later stages. The equilibrium moisture absorption rates were approximately 0.32% for PEEK resin and 0.19% for CFF/PEEK composites. After aging at 70 °C, the strength of both materials decreased significantly, while the modulus showed only minor changes. Under ETW conditions, the tensile strength retention rate of PEEK resin was 74.92%, and the compressive strength retention rate was 81.85%. For the CFF/PEEK composites, the tensile strength retention rate was approximately 85%, and the compressive strength retention rate was about 95%. The typical failure modes of CFF/PEEK composites did not exhibit notable differences between tensile and compressive specimens after hygrothermal aging. Resin debonding was observed in the moisture-absorbed composite specimens, while no microcracks or delamination were detected. The degradation of mechanical properties is predominantly attributed to the deterioration of the resin matrix and interface characteristics, which are caused by water molecule intrusion and the adverse effects of wet strain mismatch between the resin and fibers. Full article