Search Results (221)

Background: This study investigated a new multi-acid-etching formulation for zirconia ceramics, containing hydrochloric, hydrofluoric, nitric, orthophosphoric, and sulfuric acids. The solution was tested on polycrystalline (5Y-TZP zirconia), lithium disilicate, hybrid ceramic, and feldspathic porcelain to assess compatibility, etching selectivity, and surface conditioning. Methods: Two-hundred-and-forty CAD/CAM specimens were etched for 20 s, 60 s, 30 min, or 1 h, and their surface roughness and etching patterns ware evaluated using 3D optical profilometry and scanning electron microscopy (SEM). Results: A positive correlation was observed between etching time and surface roughness (Ra values). The most pronounced changes were observed in lithium disilicate and feldspathic porcelain, with Ra values increasing from 0.733 ± 0.082 µm (Group 5) to 1.295 ± 0.123 µm (Group 8), and from 0.902 ± 0.102 µm (Group 13) to 1.480 ± 0.096 µm (Group 16), respectively. Zirconia increased from 0.181 ± 0.043 µm (Group 1) to 0.371 ± 0.074 µm (Group 4), and the hybrid ceramic from 0.053 ± 0.008 µm (Group 9) to 0.099 ± 0.016 µm (Group 12). Two-way ANOVA revealed significant effects of material and etching time, as well as a significant interaction between the two factors (p < 0.001). SEM observation revealed non-selective etching pattern for the lithium disilicate groups, indicating a risk of over-etching. Conclusions: The tested etching solution increased surface roughness, especially for the lithium disilicate and feldspathic porcelain specimens. In zirconia, one-hour etching improved surface characteristics with minimal observable damage. However, additional studies are necessary to validate the mechanical stability and bond effectives of this approach. Full article

Background/Objectives: The increasing clinical integration of 3D-printed definitive resins requires a comprehensive understanding of their physicochemical properties and adhesive behavior. However, there is limited evidence regarding the optimal surface treatment and bonding strategies for clear aligner composite attachments on these materials. This study aimed to characterize a 3D-printed definitive resin, evaluate the effects of surface treatments on its surface topography, and compare the shear bond strength (SBS) of the bonded attachments using different adhesive systems, both before and after thermocycling. Methods: A total of 120 rectangular specimens were fabricated from a 3D printed dental resin (Crowntec^®, SAREMCO Dental AG—Mexico City, Mexico). For physicochemical characterization, six samples underwent scanning electron microscopy/energy-dispersive spectroscopy, X-ray diffraction, and thermogravimetric analysis. To evaluate surface topography, 42 polished specimens were assigned to three groups: untreated (control), etched with 4% hydrofluoric acid (HFA), or sandblasted with 50 µm Al₂O₃ (AA). Each group was subdivided for SEM observation and surface roughness (Ra) measurement. For SBS testing, 72 additional samples received the same surface treatments and were further subdivided according to the adhesive system: Transbond™ XT Primer (TXT) or Single Bond Universal (SBU). Results: The AA group showed the highest Ra (2.21 ± 0.30 µm), followed by HFA (0.81 ± 0.20 µm) and control (0.07 ± 0.30 µm) (p < 0.001). The highest SBS was observed in the AA + SBU group, followed by AA + TXT. Conclusions: Sandblasting with Al₂O₃ particles, combined with a universal adhesive, significantly improved bond strength, suggesting a viable protocol for 3D printed definitive composites in aligner attachment applications. Full article

Objectives: In the animal model, we aim to evaluate the bone behavior in two innovative and different laser-treated (L1–L2) titanium implants compared to sandblasted and acid-etched (SBAE) used as control. Materials and Methods: A total of twenty-seven dental implants (8.5 × 3.3 mm) used for the study (Sweden & Martina, Due Carraie Padova-Italy) were placed in three Pelibuey female sheep. Implant surface profilometric, contact angle and EDX analysis were detected. After 15, 30 and 90 days, histological, histomorphometric, SEM-EDX analysis and Bone-to-implant Contact (BIC), Dynamic Osseointegration Index (DOI) and Bone Quality Index (BQI) (as Calcium and Phosphorous atomic percentages ratio) were performed. Results: All surfaces showed relevant profilometric and wettability differences. After 15 days, BIC₁₅ showed great differences in L2 (42.1 ± 2.6) compared to L1 (5.2 ± 3.1) and SBAE (23.3 ± 3.9) as well as after 30 days (L2 (82.4 ± 2.2), L1 (56.2 ± 1.3) and SBAE (77.3 ± 0.4)). After 90 days, relevant lower BIC₉₀ values were detected in L1 (68.4 ± 0.2) compared to L2 (86.4 ± 0.1) and SBAE (86.2 ± 0.6). The DOI showed higher rates of bone growth in L2 after 15 (DOI₁₅ = 2.81) and 30 days (DOI₃₀ = 2.83), compared to L1 (DOI₁₅ = 0.38, DOI₃₀ = 3.40) and SBAE (DOI₁₅ = 1.55, DOI₃₀ = 2.58). The DOI₉₀ drastic slowdown in SBAE (0.96), L1 (0.76), and L2 (0.95) confirmed the Early Osseointegration (EO) as a crucial phase. Moreover, before loading, the lower global BQI in L1 (Ca 44.43 ± 0.08–P 46.14 ± 5.15) and SBAE (Ca 45.31 ± 2.08–P 48.28 ± 1.12) compared to L2 (Ca 79.81 ± 2.08–P 81.85 ± 3.14) allows to assert that osseointegration process and bone healing could not be considered complete if compared to the native bone. Conclusions: The BIC, DOI, and BQI results showed that osseointegration is a dynamic process, confirming the crucial role of surface characteristics able to influence it, especially the early osseointegration (EO) phase. The short-time L2 implants’ higher bone quantity and quality results, compared to L1 and SBAE, suggested the fundamental role of this innovative laser-obtained surface in “secondary stability” and predictable long-term clinical outcomes. Full article

The current investigation evaluated a novel acid-etching solution containing hydrochloric acid (HCl), hydrofluoric acid (HF), nitric acid (HNO₃), orthophosphoric acid (H₃PO₄), and sulfuric acid (H₂SO₄) designed for etching zirconia ceramics. Achieving reliable bonding to zirconia is challenging due to its chemical inertia, unlike lithium disilicate, which can be effectively conditioned with HF etching. One hundred and twenty specimens of zirconia and lithium disilicate underwent etching with the experimental solution for six different durations: control, 20 s, 60 s, 5 min, 30 min, and 1 h. Surface roughness was assessed using 3D optical profilometry and scanning electron microscopy (SEM). The roughness of both materials increased with etching time; however, lithium disilicate demonstrated a significantly greater response, with Ra values rising from 0.18 µm (control) to 1.26 µm (1 h), while zirconia increased from 0.21 µm to 0.60 µm. ANOVA revealed significant effects depending on the ceramic type, time, and their interaction (p < 0.001). SEM images revealed non-selective etching of lithium disilicate, suggesting potential over-etching. The novel acid-etching solution improved surface roughness, especially in lithium disilicate ceramics. An application duration of one hour appears optimal for zirconia, improving surface characteristics while reducing damage; however, further research is required to assess its clinical safety and long-term effects on the mechanical properties of this dental ceramic. Full article

The aim of this study was to develop an experimental self-etch dental adhesive (SE) by synthesizing graphene oxide–functionalized zirconia (GO-ZrO₂) and hydroxyapatite–functionalized zinc (HA-Zn) as inorganic powders together with bis-GMA _(0–2) (bisphenol A-glycidyl methacrylate) oligomers as main components of the organic matrix. The adhesive was compared to the current gold standard adhesive Clearfill SE Bond 2 (CSE) using cytotoxicity assays, shear bond strength (SBS) tests, and resin–dentin interface analyses. Cytotoxicity assays with human gingival fibroblasts (HGF-1) revealed reduced cell viability at early time points but indicated favourable biocompatibility and potential cell proliferation at later stages. SBS values for the experimental adhesive were comparable to CSE after 24 h of storage while aging did not significantly affect its bond strength. However, SBS exhibited more consistent resin tag formation and higher Weibull modulus values post-aging. A scanning electron microscopy (SEM) analysis highlighted differences in resin tag formation, suggesting the experimental adhesive relies more on chemical bonding than micromechanical interaction. The experimental adhesive demonstrated promising potential clinical properties and bond durability due to the integration of GO-ZrO₂ and HA-Zn fillers into the adhesive. 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

Background/Objectives: The structural integrity and strength of the transgingival soft tissue seal around dental implant surfaces remain critical challenges. Therefore, animal models should include all three implant/tissue interfaces: bone, connective tissue, and epithelium. Thus, we sought to explore the rabbit mandibular diastema as a site for candidate intra-oral implant placement. Methods: Ninety-six custom mini-implants (with one of four different surfaces: machined, acid-etched, and with or without a nanotube coating) made from titanium 6/4 alloy were placed in the mandibular diastemas of twenty-four 16-week-old New Zealand white rabbits, with the implant collar above the alveolar crest. After 7, 21, and 42 days, the bony and connective tissue/implant interfaces were examined by light and scanning electron microscopy (SEM). Results: Of ninety-six implants, eight implants were found exposed to the oral cavity, with no evidence of soft tissue inflammation, suggesting that transmucosal implant placement would have been feasible. No significant differences were observed in collagen fiber orientation and fibrous tissue thickness by polarized light microscopy. However, SEM images showed that at all three time points, topographically complex nanotube surfaces had a profound effect on soft tissue peri-implant deposition, although functionally oriented collagen fibers were not identified attached to the implant surface. These surfaces also showed reparative peri-implant bone in the collar region. An intramembranous form of de novo bone formation was observed, together with tartrate-resistant acid-phosphatase-positive osteoclasts and multinucleate giant cells in the peri-implant endosseous compartment. Conclusions: Our results demonstrate that the rabbit mandibular diastema provides an intra-oral method of implant placement without the necessity of an extra-oral approach, tooth extractions, or bone augmentation procedures. Furthermore, given that three implant tissue interfaces can potentially be studied (bone, connective tissue, and epithelium) this model provides advantages over more traditional implant placement sites in the appendicular skeleton. Full article

Background: Dental fluorosis can affect the micromorphology of dentin, a fact that could present constraints relating to the structural, mechanical, and chemical stability of dentin when it is demineralized in operative maneuvers. Introduction: The aim of this article is to quantify the amount of calcium and the microhardness of both a healthy and a fluorotic dentin through conditioning with a two-step self-etching system (Optibond Versa, Kerr, CA, USA). Methods: Dentin samples were obtained from healthy molars diagnosed with mild, moderate, and severe fluorosis. The amount of calcium was quantified utilizing an atomic absorption spectrophotometer. The hardness was evaluated using a Vickers durometer. Two dentin samples from each study group were examined using scanning electron microscopy (SEM). Results: A one-way analysis of variance (ANOVA) and Tukey–Kramer test were applied as post hoc tests for determining the differences in calcium values between the study groups and to show the difference in the hardnesses evaluated. The Student’s t-test was applied to related samples. The level of significance was set at p < 0.05. Statistically significant results were obtained for the amount of calcium and microhardness of the healthy dentin group. The SEM images demonstrated irregular etching patterns in the fluorotic dentin, indicating potential bonding challenges. Conclusion: In conclusion, there is a lower amount of calcium and a significant reduction in microhardness in healthy dentin when applying the self-etching system compared to fluorotic dentin. Fluorotic dentin is more resistant to demineralization, which may influence adhesive bonding strategies. Clinicians should consider adjusting conditioning protocols for optimal adhesion in fluorotic teeth. Full article

The dust generated during the sandblasting process of the sandblasted and acid-etched (SLA) method, commonly used to treat the surface of Ti dental implants, poses significant challenges in maintaining a clean manufacturing environment and ensuring safe working conditions. Nevertheless, surface modification remains crucial for improved performance of Ti dental implants. To address this problem and propose a clean and simple surface modification process to potentially replace SLA modification, this study aimed to characterize the surfaces of commercially pure Ti (cp-Ti) samples treated by acid etching and compare them with SLA-treated samples in terms of surface roughness (R_q), wettability (assessed through contact angle measurements), mineralized matrix deposition (evaluated through simulated body fluid [SBF] soaking), cell viability, cell differentiation (assessed based on alkaline phosphatase activity), and mineralization (assessed using MTT assay). Acid-etched surfaces exhibited nano- and micro-roughness and higher hydrophilicity than SLA surfaces, which is conducive to forming a highly bioactive TiO₂ surface. Moreover, acid-etched samples exhibited earlier hydroxyapatite deposition after SBF soaking than SLA samples. Furthermore, the acid-etched surfaces were nontoxic and displayed significantly higher cell viability and differentiation after seven days than SLA surfaces. These findings suggest that acid etching is a viable alternative to the SLA method, likely offering superior surface bioactivity and biocompatibility. Full article

Triple periodic minimal surface lattices have been introduced to dental and medical devices. Numerous designs of these porous structures have been proposed, but the impact of the surface properties of the different topographic lattices are not fully understood. So, this study aimed to examine the cellular and inflammatory responses to different lattice designs, including strut-based and surface-based lattices. Human osteoblasts, human umbilical vein endothelial cells, and monocytes were used to evaluate cell proliferation, osteogenic differentiation, and inflammatory response on lattices after surface treatment strategies. Post-surface treatment of chemical etching, in addition to improving the surface roughness by removing some adhered metal powder, also modulated the surface energy. The lattice design had no significant impact on cell proliferation, but higher cell proliferation was found in post-surface treated lattices, regardless of topographic design. For angiogenesis, there was no difference in the release of pro-angiogenic growth factors between topographic designs or post-surface treatment groups. Moreover, lattices with the post-surface treatment were prone to have a lower inflammation phenotype when compared to an as-printed lattice, though not in a significant manner. This study implies that different topographic lattice designs may not have a major impact on bone ingrowth; nevertheless, post-surface treatment and surface properties of lattice may have an influence on a macrophage-induced inflammatory response. Full article

This review summarizes the development of surface treatments applied to dental implants with the aim of improving their clinical performance. It covers the advancement of various techniques, from the conventional to the more advanced ones. Among the recent advancements, surface texturing has enabled atomic and structural modifications of implant surfaces at the micro- and nanoscales, improving tissue–material interactions. Acid etching and atomic layer deposition applied onto implant surfaces results in optimized osseointegration by stimulating the deposition and proliferation of osteoblasts and fibroblasts. The atomic layer deposition of TiO₂, ZnO, ZrO₂, and CaCO₃ has proven effective in improving osseointegration and tackling corrosion. Corrosion is still an important issue, whereby metals released from titanium implants and their associated degradation products cause local and systemic side effects, leaving a wide avenue for future research. The development of hybrid dental implants is envisaged through new materials and technologies, such as additive manufacturing, which may play a critical role in the fabrication of patient-specific implants with tailored nano-topography capable of enhancing such properties as antibacterial activity and osseointegration. Full article

Polyetherketoneketone (PEKK) exhibits satisfactory mechanical properties and biocompatibility, with an elastic modulus closely resembling that of natural bone. This property reduces the stress-shielding effect associated with bone implants. However, the biological inertness of the PEKK surface remains a significant limitation for its application in bone tissue engineering. The objective of this study was to create a superhydrophilic 3D porous structure on the surface of PEKK to enhance biocompatibility, in terms of vascularization and bone remodeling. A combination of mechanical, chemical, and physical surface treatments was employed to modify the PEKK surface. Initially, mechanical sandblasting was used to create a rough surface to promote mechanical interlocking with bone tissue. Subsequently, chemical acid etching and physical low-temperature atmospheric plasma cleaning were applied to develop a superhydrophilic 3D porous surface. The modified surfaces were characterized for morphology, roughness, hydrophilicity, and functional groups. Cellular responses, including vascularization and bone remodeling, were evaluated to assess the potential for improved biocompatibility. The combination of acid etching and low-temperature atmospheric plasma cleaning, with or without prior sandblasting, successfully created a superhydrophilic 3D porous structure on the PEKK surface. This modified surface enhanced the tube formation in human umbilical vein endothelial cells. It also promoted the adhesion and mineralization of human bone marrow mesenchymal stem cells and slightly reduced tartrate-resistant acid phosphatase expression and F-actin ring size in mouse macrophage cells. This study introduces an innovative and effective surface modification strategy for PEKK surface, combining mechanical, chemical, and physical treatments to enhance biocompatibility. The modified PEKK surface promotes angiogenic and osteogenic responses while slightly inhibiting osteoclastic activity, making it a potential alternative for dental and orthopedic PEKK implant applications. Full article

This comprehensive review of dental resin adhesives explores their historical development, key components, recent innovations, and potential future directions, highlighting a dynamic and continually advancing field. From Buonocore’s breakthrough acid-etching technique and Bowen’s pioneering dental resin invention, successive generations of clinicians and scientists have pushed forward the technological and materials development for secure bonding, while preserving dental tissues. The review discusses the substantial advances in improving adhesive reliability, enabling more conservative treatment approaches. It also delves into enhancing fundamental adhesive components and their synergistic combinations. Recent innovations, including biostable and functional resins, nanotechnology, and bioactive components, address persistent challenges such as durability, antimicrobial efficacy, and therapeutic functionality. Emerging technologies, such as digital dentistry, artificial intelligence, and bioinspired adhesives, portend an exciting and promising future for dental adhesives. This review underscores the critical role of ongoing research in developing biocompatible, multifunctional, and durable adhesives. It aims to support dental professionals and researchers by providing a comprehensive understanding of the dynamic progression of dental adhesives, inspiring continued innovation and excellence in restorative dentistry. Full article

Titanium (Ti) thin films deposited on insulated substrates were progressively anodized and formed titanium dioxide (TiO₂) nanotube arrays on the surface through a customized anodization tool designed to improve the uniformity and diameters of the nanotubes. With a motorized vertical moving arm attached to the anode, the sample was gradually submerged into the electrolyte at a controlled speed alongside the continuous anodization from the edge to the center to prevent the discontinuation of the conductive Ti layer and its nanotube surface. The effects of Ti deposition rate, anodization voltage, NH₄F concentration, and post-etching conditions on nanotube morphology were also explored. Scanning electron microscopy (SEM) analysis revealed that smaller Ti grain sizes, higher anodization voltages, higher electrolyte concentrations, and optimized post-etching times produce uniform, mature nanotubes with larger diameters, which are crucial for practical applications. This work enhances the applicability of nanotube surfaces with non-conductive substrates, such as Zirconia dental implants, and establishes a foundation for future process optimizations. Full article

Sandblasting and acid etching are common procedures used to treat implant surfaces, enhancing osseointegration and improving clinical success rates. This clinical study aimed to evaluate the long-term outcomes of sandblasted and acid-etched implants. A total of 303 implants were placed in 114 partially and totally edentulous patients using a two-stage surgical technique and an early loading protocol (6–8 weeks). Clinical findings for implants and prosthetics were evaluated over a 12-year follow-up period. A total of 12 implants (3.9%) failed, with 3 failures occurring during the healing period before loading and 9 due to peri-implantitis. The cumulative survival rate for all implants was 96.1%. A total of 156 prostheses were placed on 300 implants, 87 single crowns, 45 partial fixed bridges, 9 full-arch fixed restorations, and 15 overdentures. The mean marginal bone loss was 1.18 mm. (SD. 0.64 mm.). Thirty-nine implants (13%) in twenty-four patients exhibited peri-implantitis. Technical complications, including prosthetic screw loosening or fracture, ceramic chipping, and acrylic fractures, were observed in 24 subjects (21.1%). Sandblasted and acid-etched surface implants placed in the maxilla and mandible reported favorable outcomes and stable tissue conditions with an early loading protocol. Full article