Dental Materials最新文献

Objectives: To examine whether the effectiveness of current dentin-priming approaches requiring solvated hydrophilic resins may be replicated by modifying the infiltration dynamics of neat methacrylate-based monomers into dry-etched dentin using dimethyl sulfoxide (DMSO) pretreatments.

Methods: H₃PO₄-etched mid-coronal dentin surfaces from human molars were air-dried for 30 s and randomly pretreated with 50 %(v/v) ethanolic DMSO for 20 or 60 s. Untreated samples and an isolated wet-bonding group served as controls. Samples were bonded with a three-step etch-and-rinse adhesive or simply with the solvent-free hydrophobic-rich resin. Restored crown segments (n = 7/group) were stored in distilled water for 24 h and sectioned for microtensile bond strength testing. Resin-dentin beams (0.8 mm²) were tested under tension until failure (0.5 mm/min) after 24 h or 2 years of storage in artificial saliva at 37 °C. Nanoleakage evaluation and hybrid layer characterization were performed by SEM. Bond strength data was examined by three-way ANOVA followed by Tukey and Dunnett's test (α = 0.05).

Results: Pretreatments significantly affected the ability of neat and solvated resins to bond to etched-dry dentin (p = 0.001). Ageing significantly lowered bond strengths depending on resin composition and DMSO-application times (p = 0.007). While hybridization of DMSO-treated dentin with the solvated resin produced no significant reductions in bond strengths after ageing (p < 0.05) improving hybrid layer integrity, direct bonding of the neat hydrophobic-rich resin matched the long-term bonding performance of the "gold standard" wet-bonding protocol (p > 0.05).

Significance: Lowering dentin's hydration state via DMSO-dry bonding allows direct coupling of neat methacrylate-based resins, which may contribute to developing new strategies to ultimately extend the durability of resin-dentin interfaces.

Objective: This study evaluated the degree of conversion (DC), polymerization kinetics, and temperature of a new self-cure bulk-fill resin-based composite (Stela Automix, SDI).

Methods: The study was divided into seven groups: (1) Stela Primer, (2) Stela Automix, (3) Stela Automix exposed to light for 20 s after 100 s, (4) Stela Primer with Stela Automix, (5) Stela Primer with Stela Automix and exposed to light for 20 s after 100 s, (6) Scotchbond Universal with Stela Automix, and (7) Scotchbond Universal with Stela Automix and exposed to light for 20 s after 100 s. The real-time reaction rates and DC at the bottom of 2 mm thick specimens at ∼32 °C were measured at 720 s after insertion using a spectrometer with an Attenuated Total Reflectance detector. The temperature of Stela, Stela exposed to light, Stela Primer with Stela, and Stela Primer with Stela exposed to light were measured by an infrared thermal camera in human molar teeth with Class I cavities. The temperature was recorded in real-time every 0.03 s for 720 s. The results were compared with ANOVA and Tukey's multiple comparison test (α = 0.05).

Results: The highest degree of conversion (DC) at the 2 mm depth was achieved when Stela Primer was combined with Stela (72.4 ± 3.5 % at 720 s). Stela could self-cure independently, but not as rapidly or effectively as when used with its Primer. The greatest temperature increase was for the light-cured Stela, followed by Stela Primer with Stela RBC exposed to light for 20 s. The Scotchbond Universal bonding system did not significantly increase the DC compared to Stela alone, except when exposed to light for 20 s, which slightly increased the final DC. Exposing Stela to light for 20 s did not improve the final DC of Stela as much as using the Stela Primer, but it did increase the temperature and prolonged the time taken to return to 37 °C.

Significance: The Stela primer accelerates the degree of conversion of Stela. The reaction occurred rapidly and achieved a higher DC at the bottom of the specimens where the Stela was in contact with the Stela primer. Exposing Stela to light for 20 s is not recommended. Instead, Stela should be used with Stela Primer.

Objectives: The review assess the potential of hydrogel-based drug delivery systems in treating periodontitis. Hydrogels are classified based on source, composition, configuration, crosslinking methods, ionic charge, and response to stimuli.

Methods: The methodology comprised of comprehensive data collection from WoS, Scopus and PubMed databases covering the period of 2004-2024 of 626 documents. A bibliometric analysis was conducted using VOS Viewer to identify research trends, key contributors, prominent topics, and leading journals. A comparative analysis was performed to examine the benefits of hydrogels over conventional periodontitis treatments. Current research and innovations in hydrogel formulations were reviewed, including ongoing clinical trials and commercial products.

Results: China was found to be the leading contributor to hydrogel research in periodontitis, with key topics including "hydrogels," "nanoparticles," and "drug delivery." A detailed classification system for hydrogels was established, aiding in their application for targeted drug delivery and tissue regeneration. Hydrogels were found to offer controlled drug release, support for tissue regeneration, and improved clinical outcomes compared to traditional treatments. Innovations highlighted including the use of various polymers like nano-hydroxyapatite/collagen composites, PLGA-based materials, and chitosan gels in clinical trials, demonstrating enhanced cell proliferation and tissue regeneration.

Significance: This review underscores the significant potential of hydrogel-based therapies in advancing the treatment of periodontitis. By providing a comprehensive bibliometric analysis and highlighting key research and innovations, it emphasizes the advantages of hydrogels in terms of targeted drug delivery, minimal invasiveness, and support for tissue regeneration. The findings suggest that with further clinical trials and regulatory approvals, hydrogels could become a mainstream, effective treatment option for periodontitis, offering improved patient outcomes and potentially transforming periodontal therapy.

Objectives: Engineering spheroids to create three-dimensional (3D) cell cultures has gained increasing attention in recent years due to their potential advantages over traditional two-dimensional (2D) tissue culture methods. Stem cells derived from human exfoliated deciduous teeth (SHEDs) demonstrate significant potential for pulpal regeneration applications. Nevertheless, the feasibility of microsphere formation of SHEDs and its impact on pulpal regeneration remain unclear.

Methods: In this study, SHEDs were isolated, identified, and cultured in ultra-low attachment six-well plates to produce SHED microspheres. The biological properties of SHED microspheres were compared to those of traditional 2D culture using live-dead staining, Alizarin red staining, Oil-red O staining, scratch experiments, Immunofluorescence, Transmission electron microscopy scan, Western blotting, RNA sequencing, and a nude mice subcutaneous transplantation model.

Results: We found SHED cells can form microspheres with a dense internal structure. SHED microspheres exhibited notable advantages over SHED cells in terms of biological properties, maintaining cell activity and enhancing cell differentiation, migration, and stemness in vitro. RNA-seq revealed that the SHED microspheres potentially influenced cell development, regulation of neurogenesis, skeletal system development, tissue morphogenesis singling pathway. In vivo, SHED microspheres promoted the generation of pulp tissue in dental pulp compared to traditional 2D culture.

Conclusions: Microsphereization of SHED through 3D cell culture enhances its pulp regeneration capacity, presenting a novel strategy for dental pulp regeneration and the clinical treatment of dental pulp diseases.

Objectives: To conduct a systematic review and network meta-analysis (NMA) to answer whether endocrown restorations have similar mechanical behavior than other traditional core-crown systems with or without intracanal posts for the rehabilitation of anterior endodontically treated teeth.

Methods: The review followed the PRISMA Extension Statement for NMA. Studies were identified by a systematic search to select reports on endocrown restorations in anterior teeth. A search was performed in PubMed (MEDLINE), Scopus, Web of Science, Embase, SciELO, and LILACS databases. Articles evaluating mechanical performance through in vitro and finite element analysis (FEA) studies were selected and the risk of bias was assessed using the RoBDEMAT and ROBFEAD tools, respectively. The data were analyzed qualitatively and quantitatively through NMA using the MetaInsight tool.

Results: Eleven articles were included (eight in vitro and three with FEA design). Six in vitro studies were evaluated using NMA. Composite resin endocrowns showed greater load-to-fracture and lower occurrence of catastrophic failures than traditional restorations. Combining glass fiber post with composite restoration also showed good strength behavior. Regarding FEA studies, two out of three studies showed a more homogeneous distribution of stress for the endocrown group.

Significance: Endocrowns performed similarly to or better than conventional restorative strategies, with composite resin being the most recommended material of choice. The rehabilitation of endodontically treated anterior teeth with extensive coronal destruction is typically challenging for the dentist, and there is still no consensus in the literature that provides conclusive answers for choosing the appropriate material and restorative strategy. Exploring new techniques and materials that make this procedure easier for the dentist and guarantee good results is paramount.

Objective: The purpose was to compare the biomechanical behavior of single-piece post-core restorations made from polyaryletherketone materials with fiber post-core restorations when serving as abutments for RPD using finite element analysis (FEA).

Methods: Phantom maxillary central incisor and mandibular second premolar were trimmed 1-mm coronally to cemento-enamel junction; root canals were enlarged and the teeth were scanned. Data was transferred to a solid modeling software.Twenty four models, including six post-core restorations:glass-fiber post/composite core (GFH/GFL) and single-piece post-core groups as, PEKK(PKH/PKL);Ti0₂-reinforced PEEK(TH/TL);ceramic reinforced PEEK(CeH/CeL);carbon fiber reinforced PEEK(CaH/CaL);glass fiber reinforced PEEK(GFPH/GFPL) with hybrid ceramic/lithium disilicate crowns on each tooth were constructed.Loads of 100 N for central incisor, and 300 N for premolar in a 45°oblique direction were applied to simulate masticatory forces. Clasp removal force of a RPD was simulated as 5 N vertically.FEA was employed to evaluate the von Mises stresses.Strain at cement layer was also investigated.

Results: CaH/CaL groups revealed the lowest stress for both teeth at root while TH/TL groups revealed the highest stress. The lowest stress values in the post-core were in GFH/GFL groups while the highest stress occurred in the CaH/CaL groups for both teeth.

Significance: Glass-fiber post-cores exhibited the lowest stresses in the post under masticatory and clasp removal forces. It may suggest a potentially lower risk of post fracture compared to polyaryletherketone group materials. TiO₂-reinforced PEEK post-cores exhibited the lowest stresses among PAEK materials, indicating a potentially high fracture resistance.