Search Results (96)

This study aimed to develop experimental filler-reinforced resin composites for vat-photopolymerization 3D printing and to evaluate the effects of filler addition on their mechanical, physicochemical, and bonding properties for dental restorative applications. Silanized nano- and/or micro-fillers were incorporated into acrylic resin monomers to formulate photocurable resins suitable for vat-photopolymerization. The rheological behavior of these liquid-state resins was assessed through viscosity measurements. Printed resin composites were fabricated and characterized for mechanical properties—including flexural strength, flexural modulus, and Vickers hardness—both before and after 8 weeks of water immersion. Physicochemical properties, such as water sorption, water solubility, and degree of conversion, were also evaluated. Additionally, shear bond strength to a resin-based luting agent was measured before and after artificial aging via thermocycling. A commercial dental CAD-CAM resin composite served as a reference material. Filler incorporation significantly improved the mechanical properties of the printed composites. The highest performance was observed in the composite containing 60 wt% micro-fillers, with a flexural strength of 168 ± 10 MPa, flexural modulus of 6.3 ± 0.4 GPa, and Vickers hardness of 63 ± 1 VHN, while the commercial CAD-CAM composite showed values of 152 ± 8 MPa, 7.9 ± 0.3 GPa, and 66 ± 2 VHN, respectively. Filler addition did not adversely affect the degree of conversion, although the relatively low conversion led to the elution of unpolymerized monomers and increased water solubility. The shear bond strength of the optimal printed composite remained stable after aging without silanization, demonstrating superior bonding performance compared with the CAD-CAM composite. These findings suggest that the developed 3D-printed resin composite is a promising candidate for dental restorative materials. Full article

Background and Objectives: Ensuring the optimal shear bond strength (SBS) is essential for the long-term success of prosthodontic restorations. Our in vitro study aimed to evaluate the SBS of three types of ceramics (feldspathic, alumina, and lithium disilicates) using three adhesive cements (Variolink Esthetic LC, Variolink Esthetic DC, and Maxcem Elite). Materials and Methods: Healthy molars were prepared, and ceramic blocks were cemented following universally accepted luting protocols. SBS tests were performed using a custom-made testing machine. A multiple linear regression model assessed the effects of ceramic type, surface treatment, and luting agent on SBS. Results: The regression model explained 61.3% of the variation in SBS values (R² = 0.613); the adjusted R² = 0.605 confirmed the model’s robustness. The global F-test was statistically significant (F = 78.96, p < 0.001). The total-etch technique (+4.47), the use of feldspathic ceramic, and 5% hydrofluoric acid treatment (+3.28) significantly affected SBS. Feldspathic ceramic and lithium disilicate showed superior performance against alumina. Light-cured and self-cured cement showed negative effects. Conclusions: Ceramic material and cement type have combined effects on SBS. Optimal results were obtained with the total-etch technique, feldspathic ceramic, 5% hydrofluoric acid treatment, and dual-cured cement. Full article

Glass ionomer cements (GICs) have been clinically attractive dental restorative materials for many years and are widely used as luting, lining, and restorative materials. However, these materials still have limitations in terms of weak physio-mechanical properties. The aim of the study was to evaluate the effect of zirconium oxide nanoparticles (nano-ZrO₂ particles) on the physical and mechanical properties of two commercially available GICs. Four groups were prepared for each material: the control group (without nanoparticles) and three groups modified by the incorporation of nanoparticles at 2, 5, and 7 weight% (wt%). Firstly, the morphology and size of the nanoparticles were evaluated via scanning electron microscopy (SEM) and X-ray diffraction (XRD). Secondly, flexural strength, flexural modulus, Vickers hardness, water sorption, and solubility were evaluated. The main effect plots revealed that the addition of nano-ZrO₂ particles enhances flexural strength, flexural modulus, and water sorption of GICs at a 7 wt% concentration and Vickers hardness at a 2 wt% concentration. The SEM analysis clearly shows that the cracks became narrower with the addition of nano-ZrO₂ particles, whereas these cracks were completely closed at 7% nano-ZrO₂ particles. The findings of the study appear promising, and it is anticipated that the optimization of nano-ZrO₂ particles may aid the development of improved materials for load-bearing restorations. Full article

Background/purpose: Fiber-reinforced materials are commonly used as biobases beneath indirect restorations, potentially affecting the seating and marginal accuracy of the restorations. This study intended to assess the impact of various biobase techniques on the marginal adaptation of lithium disilicate overlay restorations. Methods: Fifty sound maxillary first premolar teeth of comparable dimensions were prepared using a full-bevel overlay design (3 mm occlusal reduction) and allocated randomly to five groups as follows (n = 10): Group A, delayed dentin sealing; Group B, immediate dentin sealing using Optibond FL; Group C, immediate dentin sealing with a 1 mm flowable composite layer (Clearfil AP-X Flow); Group D, immediate dentin sealing followed by a 1 mm short-fiber-reinforced composite layer (everX Flow); and Group E, immediate dentin sealing coated with a 1 mm flowable composite layer reinforced with polyethylene Ribbond fibers. Digital impressions were obtained using a Medit i700 intraoral scanner, and the overlays were digitally designed via the Sirona inLab CAD software and milled via a four-axis milling machine. The overlays were luted with a preheated composite (Clearfil AP-X). Marginal gap assessments were conducted pre- and post-cementation via a digital microscope at 230× magnification. The data were statistically analyzed using a one-way analysis of variance and paired t-tests. Results: The one-way ANOVA disclosed no significant differences among the groups before or after cementation (p > 0.05). Conclusions: The presence or absence of fiber-reinforced biobases did not impact the marginal adaptation of the restorations; these biobases can be incorporated to optimize the mechanical behavior of indirect restorations without adversely affecting their seating accuracy. These findings suggest that fiber-reinforced and non-reinforced biobase techniques can be safely integrated into clinical adhesive protocols to enhance the mechanical performance of restorations without comprising their marginal adaptation. Full article

All-ceramic restorations are the foundation of modern restorative aesthetic dentistry. The industry for dental materials now provides a large selection of biomaterials with a range of constantly improving qualities. Although this is undoubtedly advantageous, the vast array of materials may confuse even experienced dentists. Even if recently the demand of digital dentistry in daily dental practice has significantly increased, due to a lack of understanding concerning cementation techniques, which are different for each type of ceramic used, dentists are continuing to be hesitant to utilise these various CAD/CAM materials. This study analysed 58 articles from 2008 to 2025, focusing on narrative, comprehensive, and systematic reviews and in vitro studies on dental dentistry materials. English articles were included, but non-English articles and case reports were excluded. The analysis included articles from all journal categories, ensuring adherence to inclusion and exclusion criteria. The aim of the research is to assess material classifications and properties that guide practices concerning the adhesive cementation of all-ceramic restorations. In order to provide a clear overview of the composition, characteristics, clinical considerations, and current trends of contemporary dental materials, as well as some recommendations for future research in this area that would be relevant to dentists and the scientific community, the authors of the paper were guided by this structure when writing the article content. The key is to ensure the aesthetics, resistance, and long-term clinical success of the treatment plan by providing dental professionals with clear, accurate information and instructions about resin-luting materials and indirect restoration materials. Full article

Objective: Selecting suitable materials and luting agents for single crowns is critical yet challenging, as dentists must consider different factors. This study aimed to assess dentists’ preferences for materials and luting agents under different clinical conditions and evaluate the nonclinical factors influencing their preferences. Methods: A paper-based survey supplemented with photographs illustrating anterior and posterior single-crown preparation designs was used, incorporating three clinical scenarios for each as examples. Participants provided demographic data and were asked to select their preferred material and luting agent for each scenario. Comparisons between the crown material/luting agent choices and dentist/practice characteristics were performed. Significant differences were determined using the chi-square test. Results: Overall, 262 (87.3%) dentists participated in this survey. The top-selected material for anterior preparation designs was lithium disilicate; monolithic zirconia was the most selected for posterior preparation designs. Dual-cure resin was the most selected luting agent for all anterior and posterior clinical scenarios, except for posterior subgingival preparation design. There was a significant association between the dentist’s age and the selection of material and luting agent (p < 0.05) in all clinical scenarios, except for the luting agent selection in the posterior subgingival preparation designs (p < 0.05). Other nonclinical factors yielded mixed results; some preparation designs showed significant differences, while others did not, depending on the clinical scenario. Conclusions: Reliance on new materials and luting agents that require minimally invasive treatment with dental ceramics and resin cement is increasing. However, the choice of materials and luting agents is influenced by clinical presentation and nonclinical factors, making it crucial for dentists to be aware of these factors when selecting materials for single-crown restorations. Clinical Implications: An overall trend was observed for the use of strong monolithic ceramics with adhesive resin cements. These findings could assist dentists in reviewing and re-evaluating material choices in their clinical practices, both at a national and regional level. Additionally, the findings could be useful for dental policy makers, wholesale suppliers, and retail distributors in making future decisions. Full article

This study investigated the effects of varying concentrations of two distinct silane agents, 8-methacryloxyoctyl trimethoxy silane (8-MOTS) and 3-methacryloxypropyl trimethoxy silane (γ-MPTS), on their initial bonding efficacy to feldspathic ceramic (FC), lithium disilicate glass-ceramic (LD) and polymer-infiltrated ceramic (PIC) specimens, in 10% increments for concentrations ranging from 10% to 40%. Shear bond strengths between the ceramic substrates and the luting material were assessed following 24 h incubation in distilled water. For FC, the median value of shear bond strength peaked at 20% of γ-MPTS (7.4 MPa), while 8-MOTS exhibited a concentration-dependent increase, reaching its highest value at 40% (13.1 MPa). For LD, γ-MPTS above 10% yielded similar strength median values (10.2 MPa), whereas 8-MOTS at 30% (15.8 MPa) and 40% (13.4 MPa) yielded higher strength values than at 10% (2.9 MPa) and 20% (4.1 MPa), with the highest median value exhibited at 30%. For PIC, both γ-MPTS and 8-MOTS demonstrated similarly low bond strength values which were not significantly different from the non-silane-treated specimens. When applied on silica-based FC and LD, silane revealed a concentration-dependent bonding effect, with 8-MOTS exhibiting superior bond strength to γ-MPTS. However, PIC, characterized by a high inorganic filler content, demonstrated limited bondability with both silanes. Full article

Background: Root canal sealers remain in long-term contact with dental tissues, raising concerns about their potential adverse effects. Methods: This study evaluates the physicochemical properties and ion-release profiles of three dental materials: zinc oxide/eugenol-based sealer, zinc phosphate cement (luting agent), and glass-ionomer cement (restorative material) under acidic (pH 4) and neutral (pH 7) conditions over 24 h and 30 days to determine their behavior and bioactivity in vitro. The materials were evaluated for their setting time, consistency, film thickness, solubility, and ion release using atomic emission spectrometry. The influence of pH and exposure time on ion release was analyzed using multiple regression analysis. Results: All tested materials met the ISO standards for their respective categories. The zinc oxide/eugenol and zinc phosphate cements released increased levels of zinc in acidic environments (pH 4), suggesting potential antimicrobial properties. The glass-ionomer cement exhibited higher silicon and strontium release under a neutral pH (pH 7), indicating potential remineralization effects. Silver from the zinc oxide/eugenol material was below the detection limit of the applied method, suggesting minimal ion release under the tested conditions. Maximum zinc release from root canal sealer occurred after 30 days at pH 4 (1.39 ± 0.26 mg), while the highest silicon release from glass-ionomer cement was observed at pH 7 after 30 days (1.03 ± 0.21 mg). Conclusions: Zinc oxide/eugenol materials exhibited increased zinc release under acidic conditions. In contrast, the restorative and luting materials demonstrated distinct ion-release patterns, aligning with their respective intended applications rather than endodontic purposes. Full article

Although glass ionomer cements (GIC) are widely used in dental restorations, their long-term performance remains limited by their mechanical properties, including surface roughness and fracture resistance. This study investigates the synthesis of nano-silica from Thalassiosira sp. diatoms through the sol-gel process and its application in influencing the mechanical and physical properties of GIC luting materials. A control group and three experimental groups of different nano-silica concentrations (1%, 3%, and 5%) were compared. Several analyses, including confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), and universal testing machines (UTM), were used to determine layer thickness, surface roughness, compressive strength, and tensile strength. Statistical analysis exhibited significant differences between the groups (p < 0.05). The 3% nano-silica group indicated an optimal compromise between mechanical strength and surface smoothness, while the 5% group showed increased thickness and roughness with slightly lower strength. These findings emphasize that the sol-gel-derived nano-silica from Thalassiosira sp. potentially enhances certain characteristics of GIC for possible dental cementation. Further research is needed to determine the long-term durability and bioactivity of these modified materials. Full article

Objectives: This study aimed to analyze the load-bearing performance of upper incisors and evaluate the curing of the luting polymer composite at various depths within the canal. Methods: A total of one hundred maxillary central incisors (10 groups, n = 10/group) were subjected to various restorative techniques. Approach A used Gradia Core for post-core and crown; Approach B employed prefabricated fiber posts (4 mm or 8 mm) with Gradia for luting and core build-up; Approach C used short-fiber composite (everX Flow) for post-core build-up; and Approach D used fiber posts with everX Flow for luting and core build-up. Restorations underwent cyclic fatigue (40,000 cycles at 95 N) and quasi-static fracture testing. Surface hardness of luting polymer composites was also measured. Results: Data showed that restorations with additional fiber posts (Approaches B and D) had significantly higher load-bearing capacity (p < 0.05), while post material and length had no significant impact (p > 0.05). Short-fiber composite as luting and core material (Approach D) enhanced load-bearing performance compared to Gradia-based restorations (Approach B, p < 0.05). Conclusions: The use of short-fiber composite as both the post luting and core material in restoring compromised incisors, along with a conventional fiber post, demonstrated favorable results in terms of load-bearing capacity. Full article

The widespread implementation of new CAD/CAM materials has led to the necessity of establishing an adequate luting protocol. The aim of this study was to evaluate the microtensile bond strength (μTBS) and the film thickness of different luting methods on CAD/CAM resin blocks. Five Brilliant Crios CAD/CAM blocks (Coltene/Whaledent) were sequentially sectioned into two halves, air abraded with 50 µm aluminum oxide, and luted according to five different cementation protocols: Brilliant EverGlow (BEG), Brilliant EverGlow with ultrasound application (BEG-US), preheated Brilliant EverGlow (BEG-H), Brilliant EverGlow Flow (BEGF), and Duo Cem^® Trans (DC). Subsequently, the blocks were sectioned to obtain rods, which were then submitted to a microtensile bond strength test (n = 20). The surfaces were examined with optical microscopy to determine the failure mode and the bonding interface was assessed with scanning electron microscope (SEM) analysis. Bond strength values were analyzed using one-way ANOVA and Tukey’s post hoc tests (α = 0.05). The bond strength values varied with the different cementation protocols (p < 0.001): BEG (45.48 ± 18.14 MPa), BEG-US (42.15 ± 14.90 MPa), BEG-H (41.23 ± 15.15 MPa), BEGF (58.38 ± 15.65 MPa), and DC (81.07 ± 8.75 MPa). Regarding bond strength, DC presented significantly higher values than all other experimental groups (p < 0.050), whereas all luting methods using BEG presented similar values (p = 0.894). Adhesive failures were the predominant type. On SEM evaluation, all the luting materials presented a tight and homogeneous cement–block interface with variable film thicknesses. In conclusion, among the cementation protocols, the resin cement (DC) rendered the highest bond strength values. SEM analysis revealed that the lowest film thickness was associated with the flowable composite (BEGF). Full article

Background/Objectives: This study aimed to investigate the microtensile bond strength (µTBS) of composite-based (Cerasmart), polymer-infiltrated (Vita Enamic), and feldspathic (Cerec) CAD/CAM blocks luted to dentin using a dual-cure resin cement (LinkForce), as well as micro-hybrid (G-aenial) and flowable composites (G-aenial Universal Flo), and evaluate the microhardness (HV) of luting materials through the CAD/CAM blocks. Methods: Cerasmart, Enamic, and Cerec were luted to dentin using three luting materials; LinkForce, G-aenial, and Universal Flo (n = 5). For HV, 117 disk-shaped specimens from LinkForce, G-aenial, and Universal Flo (n = 13) were polymerized through 3 mm thick CAD/CAM. Thirty-nine light-cured specimens without CAD/CAM were used as control. Following 24 h storage, the µTBS and HV were evaluated. Data were analyzed using the two-way ANOVA and post hoc Tukey tests (p < 0.05). Results: The µTBS to dentin and HV were significantly influenced by the type of luting material and CAD/CAM material. With all the CAD/CAM materials, LinkForce and Universal Flo exhibited a significantly similar µTBS to that of dentin (p > 0.05). Compared with the control group, all the HV values of the luting materials decreased significantly (p < 0.05). Conclusions: Heavily filled flowable composites exhibit a bonding effectiveness similar to that of dual-cure resin cements. All the luting materials showed similar HV when polymerized through the polymer-infiltrated CAD/CAM material. Full article

The purpose of this study was to compare the wear resistance of light-cure resin luting cements for veneers with that of other luting materials investigated in earlier studies. An Alabama wear-testing machine was used to measure the wear resistance of four recent light-cure resin luting cements for veneers (G-Cem Veneer; Panavia V5 LC; RelyX Veneer Cement; and Vario-link Esthetic LC). The volume loss ranged from 0.027 ± 0.003 to 0.119 ± 0.030 mm³, the mean facet depth from 56.053 ± 7.074 to 81.531 ± 7.712 µm, and the maximum facet depth from 100.439 ± 26.534 to 215.958 ± 27.320 µm. G-Cem Veneer showed significantly better (p < 0.05) wear resistance than the other materials tested. Representative SEM images were obtained which showed differences in form among the wear facets for the luting cements examined. Correlations were calculated between the three measurements for each material, and the pattern of correlations was also different for each material. Full article

This study evaluated whether airborne-particle abrasion could be an alternative to hydrofluoric acid etching as a pretreatment for the adhesive bonding of silicate ceramic restorations. Feldspar (FEL; n = 100), lithium silicate (LiSi; n = 100), and zirconia (ZrO₂; (n = 80) substrates were CAD/CAM-fabricated and airborne-particle-abraded with Al₂O₃ (25 µm or 50 µm of mean particle size) at pressures of 0.05 or 0.1 MPa. The controls included FEL (60 s) and LiSi (20 s) etched with hydrofluoric acid. The surface free energy (SFE) and roughness (Ra) were measured. For the tensile bond strength (TBS), surfaces were conditioned using a primer (Monobond Plus) and luted to a resin composite (Variolink Esthetic). TBS was assessed initially (24 h, 37 °C water storage) and after thermocycling (5/55 °C, 10,000×). Statistical analysis (SPSS, V29) was performed using a one-way ANOVA, post hoc Scheffé, and a two-group t-test (p = 0.05). Abrasion with 50 µm and 0.1 MPa induced the highest Ra values across the materials (62.5 ± 3.88 µm). ZrO₂ exhibited a higher TBS (35.4–49.5 MPa) than FEL and LiSi. For aged LiSi, the specimens treated at 0.1 MPa showed a higher TBS (18.7 ± 9.0 MPa) than those treated at 0.05 MPa, regardless of the particle size. The etched and aged FEL showed a higher SFE but a lower TBS compared to abrasion. Al₂O₃ particle abrasion (25 or 50 µm at 0.1 MPa) may replace etching for silicate-based ceramics, while 50 µm is recommended for ZrO₂ at either pressure. Full article

Background and Objectives: This study aimed to investigate the effect of zinc phosphate (ZnP) cement, glass ionomer cement (GIC), and nano-integrated bio-ceramic (NIB) cement on mineralization when placed in contact with bone tissue-forming cells. Materials and Methods: ZnP cement, GIC, and NIB cement were divided into direct and indirect groups. A total of 72 cement pellets (24 pellets of each test sample) of 3 × 1 mm (width × height) were prepared using polytetrafluoroethylene molds. A total of 3 sample groups were demarcated using 96- cell well culture plates. In the control group, 24 wells were filled with mineralized osteoblasts and 1 µL of gingival crevicular fluid (GCF). In test group 1, to show a direct effect, 36 samples were plated with mineralized osteoblasts and 1 µL GCF for 24 h; the cells were directly exposed to cement pellets. A total of 36 samples were immersed in GCF for 24 h; later the supernatant was transferred to the mineralized osteoblasts to demonstrate an indirect effect in test group 2. To assess the mineralization, osteoblasts were stained with alizarin red and later observed under an inverted phase-contrast microscope. Data were analyzed using the statistical package for social sciences. An independent t-test compared the direct and indirect effects of the ZnP cement, GIC, NIB cement, and control groups on the mineralization of osteoblasts derived from hDPCs. Results: A statistically significant difference was observed between the ZnP cement, GIC, and NIB cement groups (p < 0.05). ZnP cement exhibited a moderate, NIB cement the least harmful effect, and GIC showed the most harmful effect on the mineralization of osteoblast cells. Conclusions: The biocompatibility of dental luting cements is an important aspect that clinicians should consider during their selection. Nano-integrated bio-ceramic cement showed the least negative effect on the mineralization of osteoblast cells which is beneficial for the cementation of cement-retained implant prostheses. However, further studies are needed to evaluate osteoblast and osteoclast activity in vivo. Full article