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Objective The aim of this study was to test the effect of different bleaching protocols on surface roughness, color stability, and translucency parameter of coffee-stained nanohybrid dental composites with different viscosities. Materials and Methods Five nanohybrid dental composites with different viscosities (n = 250)—Neo Spectra LV, Neo Spectra HV, Neo Spectra Flow (Dentsply, Konstanz, Germany), Grandio, and Grandio Flow (Voco, Cuxhaven, Germany)—were used to test surface roughness, color stability, and translucency parameter after bleaching of coffee-stained specimens using either in-office bleaching, home bleaching, or a combination of both. The viscosity of the five types of dental composites was tested using a viscometer. A scanning laser microscope (SLM) was used to examine the surface topography of representative samples from each dental composite after the combined effect of both bleaching agents. Effect of composite type, bleaching protocol, and their interaction was assessed by two-way analysis of variance. For multiple comparisons, Tukey's post hoc test was used with Bonferroni correction. Results Surface roughness of all coffee-stained dental composites increased after bleaching; however, those of Grandio and Grandio Flow increased significantly (p < 0.0001). This was confirmed by SLM images that showed rough surface with protruding fillers after in-office and home bleaching protocol. Results revealed that bleaching, regardless of the protocol, decreased the delta E values of all dental composites; however, it was still higher than the accepted threshold value of 3.7. Neither of the bleaching protocols enhanced translucency parameter of all dental composites. Neo Spectra Flow and Voco Flow had the highest translucency parameter after the three bleaching protocols. Conclusion Bleaching does not improve color stability and translucency of coffee-stained nanohybrid dental composites regardless of the viscosity. Surface roughness of coffee-stained nanohybrid dental composites increases after application of bleaching agents. [ABSTRACT FROM AUTHOR]

In recent decades, the integration of nanotechnology into dentistry has led to groundbreaking advancements in dental materials and applications. This article explores the role of nanoparticles (NPs) in modern dentistry, highlighting their definitions, unique properties, and various applications. The introduction establishes the significance of nanotechnology in dental health care, emphasizing the potential of NPs to transform traditional practices. The overview includes a discussion of the fundamental properties of NPs, which contribute to their effectiveness in dental applications. The article categorizes NPs into three main groups: antimicrobial, therapeutic, and material property-improving NPs, detailing their clinical uses and mechanisms of action. Furthermore, it addresses current innovations in dental products incorporating NPs and examines emerging trends in the field. The research for this review was conducted using high-quality, peer-reviewed scientific databases, including PubMed, Scopus, Web of Science, and Google Scholar, with no time restriction as an inclusion criterion. These databases were selected for their credibility and comprehensive collections of relevant studies. In conclusion, NPs represent a promising avenue for innovation in dental materials and therapeutics. Their unique properties enable the development of enhanced antimicrobial agents, effective drug delivery systems, and improved material performance. However, the risks associated with cytotoxicity and stability must be carefully managed to ensure safe and effective use. Ongoing research is essential to fully understand and optimize the applications of NPs in dentistry, balancing their benefits against potential health risks. As the field advances, the integration of NPs into clinical practice will likely revolutionize approaches to dental care and treatment. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the cure efficiency and biocompatibility of a novel iron-based coordination complex used as a photoinitiator in comparison to conventional ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate (TPO-L) and camphorquinone (CQ) as photoinitiators in dental 3D-printed resins. Materials and Methods: Experimental dental resin formulations were prepared by blending 1:1 ratio of Bis-GMA and TEGDMA, to which 0.2 wt% of either the iron-based coordination complex or CQ were added, along with 0.2 wt% EDAB and 0.4 wt% IOD, and the TPO-L. The degree of conversion (DC) was measured using Fourier transform infrared spectroscopy (FTIR). Biocompatibility was assessed by evaluating the viability of L929 fibroblast-like cells using the MTT assay 24 h post-exposure. Statistical analyses included a two-way ANOVA followed by Tukey's test for post hoc comparisons, with significance at p < 0.05. Results: The degree of conversion for the iron-based coordination complex (84.54% ± 1.69%) was significantly higher than that for the TPO-L (78.77% ± 1.25%) and CQ-based resins (73.21% ± 0.47%) (p < 0.001). The iron-based coordination complex and TPO-L resins exhibited significantly higher conversion than CQ-based resins (p < 0.001). Regarding biocompatibility, the cell viability test revealed that the iron-based coordination complex demonstrated the highest cell viability at 86.5% ± 10.24%, followed by TPO-L with 80.03% ± 11.07%. CQ showed the lowest cell viability of 51.29% ± 8.44% (p < 0.05). Tukey's test confirmed significant differences between CQ and other photointiators (p < 0.05), while no significant difference was found between TPO-L and the iron-based coordination complex. Conclusions: This study introduces a novel iron-based coordination complex photoinitiator that demonstrates enhanced cure efficiency and comparable biocompatibility to TPO-L, while significantly reducing the cytotoxicity associated with CQ. Its longer absorption wavelength supports deeper layer curing, making it a promising alternative for dental 3D printing, particularly in bioactive scaffold applications requiring minimized cytotoxicity. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Materials and Methods Results Conclusions This study aimed to assess the relative translucency parameter (RTP) of human enamel and dentin and set target RTP values for dental material development. Additionally, it seeks to validate the spectral RTP concept as supplementary quantitative information.Slides of extracted human teeth, 1 and 2 mm thick enamel or dentin slides, were evaluated. RTP was calculated using CIEDE2000 (RTP00) and CIELAB (RTPab) color difference formulas. Spectral RTP (SPECTRAL RTP) curves were also generated from differences between spectral reflectance values obtained against white and black backgrounds. Statistical analyses included multifactorial ANOVAs for each RTP and spectral RTP, and Pearson correlations between RTP and spectral RTP.Significant correlations were observed between the RTP and spectral RTP values (p < 0.001) at all studied wavelengths. RTP00 and RTPab values were significantly different (p < 0.001). Enamel showed more translucency than dentin (p < 0.001), and 1 mm slices were more translucent than 2 mm slices (p < 0.001).Spectral RTP values were influenced by the type of tissue (enamel, dentin), thickness (1 mm, 2 mm), and color difference formula (CIELAB2000, CIELAB). RTP curve values were influenced by tissue type, thickness, and wavelength. Spectral RTP and RTP curve values were correlated. [ABSTRACT FROM AUTHOR]

This work is dedicated to fabricated Chitosan-reinforced bamboo and nano bio-silica (1%, 2%, and 3% by volume) using the hand-layup method and investigate their mechanical properties. Mechanical characterization of samples proves that 2% volume nano bio silica-reinforced composites (C2) exhibit the highest tensile, flexural, and compressive strengths. Finite element analysis of dental implants for static and dynamic loading (60 cycles per minute) also confirmed the suitability of the C2 composites for dental implant applications, with Von-Mises stresses below the yield strength in human jaw bones. These findings highlight the potential use of bio-composite material for the dental implants in future. [ABSTRACT FROM AUTHOR]

Background: The success of a restoration largely depends on the quality of its fit. This study aimed to investigate the fit quality of monolithic zirconia veneers (MZVs) produced through traditional and digital workflows. Methods: A typodont maxillary right central incisor was prepared. The maxillary arch with the prepared tooth was scanned with Trios 3 Pod intra-oral scanner (IOS), which served as a pattern to create thirty 3D resin models through printing. Additionally, thirty conventional impressions of the maxillary with the prepared tooth were taken using polyvinyl siloxane (PVS) impression material. These impressions were cast using dental gypsum products to create thirty stone dies, which were then scanned externally. Sixty MZVs were milled from multi-layered zirconia disks. The marginal and internal gaps of restorations were assessed using the silicone replica technique. Results: The highest marginal accuracy for both the conventional and digital impression groups was observed in the cervical area, with values of 74.6 μm and 61.9 μm, respectively. The smallest internal gaps for both groups were also recorded in the cervical area, at 109.9 μm for the conventional group and 109.7 μm for the digital group. The digital group exhibited better marginal fit, particularly in the incisal and mesial areas (79.3 μm and 75.7 μm, respectively), compared to the conventional group (88.1 μm and 90.8 μm). No statistically significant differences in internal fit were observed. Conclusion: MZVs fabricated using the digital workflow exhibited superior marginal fit compared to those fabricated using the conventional workflow, though both techniques yielded clinically acceptable results. [ABSTRACT FROM AUTHOR]

Objective: To compare the translucency and contrast ratio of 13 different resin based restorative materials and to evaluate the effect of 2 different bleaching methods on the translucency and contrast ratio of these materials. Methods: In this study, a total of 260 samples were prepared, 20 from each of 13 different dimethacrylate-based restorative materials. Then, each material group was divided into 4 subgroups. While two different bleaching methods (home and office) were applied to two of these groups, the other two groups were created as separate control groups for each bleaching group. After the bleaching process, Translucency Parameters (TP) and Contrast Ratio (CR) were calculated with a spectrophotometer. The data obtained were analyzed using two-way ANOVA and Tukey post-hoc tests (p < 0.05). Results: When the bleaching groups were compared in terms of the differences between the TP values ​​in general, it was seen that the TP values ​​decreased in all groups, but this decrease was least in Opalescence PF. In terms of materials, the greatest change in TP and CR values ​​was seen in composite materials, while the least change was seen in hybrid CAD/CAM materials. Conclusions: Within the limitations of this in vitro study, the effect of bleaching agents on the translucency and contrast ratio of restorative materials depends on the material used and the bleaching method applied. Composite-based materials have been found to be more risky in terms of bleaching. For this reason, the clinician should take this into consideration, especially when performing office bleaching on teeth with restorations. [ABSTRACT FROM AUTHOR]

Background: This study aimed to assess and compare the performance of root canal treatment obturated either with calcium silicate-based or epoxy resin-based root canal sealers on retreatment cases with periapical lesions. Methods: Patients' radiographic data and clinical records were obtained retrospectively from the computerized patient record system. A total of 44 teeth, 28 teeth treated with calcium silicate-based sealer and 16 teeth treated with epoxy resin-based sealer, were included in the study. The mean follow-up period was 11.9 months for calcium silicate-based sealer and 23.6 months for epoxy resin based sealer groups. The outcome was evaluated based on radiographic findings and clinical records of the patients. Chi-square test and Fisher's Exact test were used to examine the differences between categorical variables. An independent samples t-test was used to compare the initial and final PAI differences based on sealer type. Results: The success rate was 100% for calcium silicate-based sealer and 93.75% for epoxy resin-based sealer. Calcium silicate-based sealer showed a faster healing capacity than epoxy resin-based sealer. Conclusions: Both sealers are viable options for retreatment cases, but calcium silicate-based sealer has a faster healing potential. [ABSTRACT FROM AUTHOR]

Background: Lithium disilicate occlusal veneers are popular for minimally invasive posterior teeth restoration. The aim of this study was to compare the fatigue resistance and crack pattern of lithium disilicate occlusal veneers fabricated using pressing and milling techniques with varying thicknesses. Methods: Sixty lithium disilicate discs, representing occlusal veneers, were divided into four groups (n = 15) based on processing technique (IPS e.max Press or IPS e.max CAD) and thickness (0.5 or 0.8 mm). A step-stress fatigue test was applied with axial loading, consisting of 10,000 cycles/step with a step size of 50 N until failure. Fractographic analysis was performed using SEM. Statistical analysis was performed using the Kaplan–Meier test, Mantel–Cox test, and Weibull analysis. Results: Both processing techniques resulted in similar fatigue resistances at 0.5 mm and 0.8 mm thicknesses. However, the 0.8 mm lithium disilicate restorations showed a significantly higher survival rate than the 0.5 mm lithium disilicate restorations (log-rank tests, χ2 = 58.6; df = 3; P < 0.001). Fractographic analysis revealed radial cracks originating from defects on the ceramic surface at the cementing interface, extending towards the occlusal surface. Conclusions: At 0.5 mm or 0.8 mm material thickness, the processing technique did not affect the fatigue resistance or crack patterns of the lithium disilicate occlusal veneers. However, the lithium disilicate with a thickness of 0.8 mm exhibited a superior survival probability compared to that with a thickness of 0.5 mm. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives Material and Methods Results Conclusions To evaluate the influence of different dental implant materials within the exomass on the image quality in cone‐beam computed tomography (CBCT).Five pig jaws were scanned using four CBCT devices, first without any dental implants, followed by scans with three dental implants of the same material—pure titanium, titanium‐zirconium alloy, and zirconium dioxide. Two fields of view (FOVs) were used for each device to position the implants in the exomass of a small FOV and within a large FOV. Voxel values were obtained from tubes containing a radiopaque solution to calculate mean voxel value (MVV), voxel value inhomogeneity (VVI), and image noise (IN), which were compared across implant materials and FOVs using repeated measures analysis of variance (α = 0.05). Three observers independently scored image quality using a 5‐point scale.In general, MVV remained unaffected, except for a significant increase in the X800 device when titanium or titanium‐zirconium alloy implants were in the exomass of a small FOV (p ≤ 0.05). A trend of increased VVI was observed when implants were in the exomass of a small FOV, with a greater effect for zirconium dioxide, followed by titanium‐zirconium alloy and titanium. IN was higher when implants were in the exomass, especially for zirconium dioxide implants (p ≤ 0.05). Image quality perception was consistent overall, though zirconium dioxide implants in both FOVs resulted in diminished quality.The presence of implants in the exomass can negatively affect CBCT image quality, with zirconium dioxide having the greatest impact. [ABSTRACT FROM AUTHOR]

Purpose: The retention force of a realistic clasp is influenced by multiple, interrelated factors, which complicates the identification of the fundamental relationship between clasp geometry and retention force. While realistic clasps exhibit various shapes, they share basic geometric elements such as length, diameter, and curvature. Simpler geometries are often more conducive to identifying the underlying issues. The aim is to investigate the relationship between clasp geometry and retention force using finite element analysis. Methods: A three-dimensional clasp model was created in ANSYS 19.0 (ANSYS, USA). Two types of models were analyzed: rod-shaped clasps with varying lengths (1–15 mm) and diameters (0.6–1.6 mm), and bending clasps with different base widths (6–12 mm) and heights (0.5–5 mm), all made from cobalt-chromium alloys. For the rod models, stress and retention force were assessed by applying displacement loads and analyzing data with nonlinear regression. For the bending models, a similar analysis was conducted for varying base widths and heights. Results: Maximum stress consistently concentrated at the clasp base. In rod models, retention force decreased with the third power of length and increased with the fourth power of diameter. For bent specimens, the retention force was approximately inversely proportional to the cube of the base width and inversely proportional to the first power of the height. Conclusions: Finite element analysis revealed distinct functional relationships between clasp geometry and retention force. Further laboratory validation is required. [ABSTRACT FROM AUTHOR]

Background: Achieving a stable bond with zirconia requires mechanical and chemical bonding methods. Information regarding the optimal treatment method for zirconia with varying yttrium content is scarce. This study evaluated the effect of different surface treatments on the shear bond strength of zirconia with various yttria contents. Materials and methods: A total of 168 disc-shaped zirconia specimens were classified into 12 groups based on the surface treatment method, including airborne-particle abrasion (APA), selective infiltration etching (SIE), hot etching (HE), and control group with no treatment; and yttria contents including Zolid Zi (4.5–5.6 wt% yttrium), Zolid HT White (6.7–7.2 wt% yttrium), and Ceramill Zolid FX (9.15–9.55 wt% yttrium). The surface roughness (Ra and Rz) of the specimens and the shear bond strength was measured (α = 0.05). Results: The results indicated that the mean bond strength of all specimens was higher after different surface treatments compared to the control group, of which the APA method resulted in higher bonding strength in all kinds of zirconia than other methods (P < 0.05). In all types of zirconia, a significant difference was observed in surface roughness (Ra and Rz) resulting from various surface treatment methods (P < 0.001). Interaction of surface treatment methods and zirconia type significantly affected shear bond strength and surface roughness (P < 0.05). Conclusion: APA significantly enhanced shear bond strength and surface roughness across all zirconia types and yttria contents. The SIE and HE methods also showed promising results. Zolid Zi showed superior bond strength, whereas Zolid FX demonstrated reduced bond strength. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to compare AH Plus Bioceramic Sealer (AHPB), AH Plus (AHP), MTA Fillapex (MTAF), and Sure-Seal (SS) sealers for dentinal tubular penetration ability. Methods: Forty extracted human mandibular premolars were instrumented and divided into 4 groups based on the sealer used for filling (n = 10): AHPB, AHP, MTAF, SS. After filling the root canals, the roots were entombed in acrylic resin blocks and cut vertically in the long axis to obtain 1-mm-thick disks from 3 mm (at apical third), 8 mm (at middle third) and 13 mm (at coronal third) away the apical foramen. The images of 120 samples (30 for each group) were scanned by using confocal laser scanning microscopy and analyzed with the ImageJ software. Total penetration area and the root canal area were measured, and the ratio of these values were recorded as sealer penetration ratio. The data were evaluated for each third and in total using one-way ANOVA with post-hoc Tukey's test. The significance level was set to P < 0.05. Results: In the apical, middle and coronal thirds and in total, MTAF and AHP, and SS and AHPB had statistically significant identical penetration ratio values. Both SS and AHPB demonstrated statistically considerably greater penetration % as compared to MTAF and AHP in all thirds (P < 0.05), and in total (P < 0.05). Conclusion: AHPB and SS provided a higher penetration % than AHP and MTAF in apical, middle and coronal thirds, and in total. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to investigate the effects of different types of bleaching methods and repolishing on the whiteness index and staining susceptibility of additive and subtractive production resin-based materials and direct composite resins. Methods: In this study, a total of 96 samples (8*8*2m) were prepared using a nanohybrid composite resin (Neo SpectraTM-ST (NS)), a subtractive-manufactured nanoceramic resin (CerasmartTM270 (CS)), and an additive-manufactured permanent resin (Saremco print Crowntec (CT)). The samples were randomly divided into four treatment groups: control (distilled water, 14 days), in-office bleaching (Opalescence Boost-40% HP, 3*20min), at-home bleaching (Opalescence PF-16% CP, 6 h, 14 days), and toothpaste group (Opalescence Whitening, 2*5min, 14 days) (n:8). After each the bleaching procedure was completed, the samples were kept in coffee solution for 7 days. Following, all samples were repolished. The color of the samples was measured with a spectrophotometer at baseline (T0), after bleaching (T1), after staining in coffee (T2) and after repolishing (T3). The whiteness index change (∆WID, T1-T0), staining susceptibility (∆E1, T2-T1) and color change after repolishing (∆E2, T3-T1) of the samples were calculated in the CIE (Commission International De I'Eclairage) system. The data were analyzed by SPSS software One-Way ANOVA, post-hoc Tukey, post-hoc Tamhane's-T2 and Paired-samples T test (α = 0.05). Results: The ∆WID of all tested materials was significantly different in the in-office bleaching group compared to the control group (p < 0.05). Among the bleaching groups, the highest ∆WID was obtained in-office bleaching group of CT (2.91 ± 4.12). Staining susceptibility after bleaching (∆E1) was higher in the in-office and at-home bleaching groups compared to the control group in all tested materials. However, the difference between the treatment groups was statistically significant in NS and CS (p < 0.05). The highest ∆E1 was obtained in the in-office group of CT (7.36 ± 4.82). Color changes after repolishing (∆E2) of the tested materials were less in all groups compared to ∆E1. Conclusion: In-office and at-home bleaching can increase the whiteness index change and stain susceptibility of materials. Among the tested materials, the color stability of additive-manufactured CT was comparatively poorer. The repolishing was found to be beneficial in reducing staining. [ABSTRACT FROM AUTHOR]

Background: Coronal microleakage, the passage of fluids and bacteria through the interface between the temporary restoration and the tooth structure, can potentially result in endodontic treatment failure. Purpose: This study evaluated and compared the sealing efficacy of various temporary restorative materials utilized during endodontic procedures. Methods: All seventy premolar teeth were extracted, measured, and restored, except for the negative control group, where the teeth were left whole. There were eight distinct groupings created from the teeth. Sound teeth were utilized in the n = 5 (Group 1) negative control group. A cavity after endodontic treatment was left vacant in the positive control group (n = 5, Group 2). Six experimental groups, each with ten specimens, had access cavities restored using various temporary materials (Group 3: Cavit-W, Group 4: Systemp. inlay, Group 5: Cotton + Systemp. inlay, Group 6: Cotton + Cavit-W, Group 7: Teflon + Systemp. inlay and Group 8: Teflon + Cavit-W). The teeth were submitted to thermocycling, and a microleakage test was performed. Depth of dye penetration was measured. The collected data were statistically analyzed (α = 0.05). Results: Gp 7: Teflon + Systemp. inlay obtained the lowest infiltration values with no significant difference than (Gp 4: Systemp.inlay) and (Gp 8: Teflon + Cavit-W). Whereas (Gp 5: Cotton + Systemp.inlay) and (Gp 6: Cotton + Cavit-W) presented the highest significant microleakage values among other experimental groups. Conclusion: Regarding temporization after endodontic treatment, Teflon combined with Systemp.inlay and Cavit-W presented the best temporary materials regarding microleakage control. At the same time, cotton combined with Cavit-W presented the worst temporary material for microleakage control. Cotton is not to be used in the temporization of endodontic-treated teeth. Clinical implication: Creating a tight seal in root canals that have undergone endodontic treatment is crucial for a successful, durable final restoration. Clinical and laboratory research results are an essential factor in determining how well endodontic materials seal. [ABSTRACT FROM AUTHOR]

Objective: Marginal adaptation of the provisional restoration often requires relining from relining materials. This study determined the effects of surface treatments on the shear bond strength (SBS) between 3D-printed provisional and bis-acryl relining materials. Materials and methods: The 3D-printed provisional specimens (9 × 9 × 2 mm3) were prepared using methacrylate-based material. Five test groups (n = 15) based on surface treatments were evaluated; (1) no treatment (CT), (2) ethanol (ET), (3) universal adhesive; CLEARFIL TRI-S BOND Universal Quick (UA), (4) airborne-particle abrasion with 50 μm aluminum oxide particles (AA), and (5) airborne-particle abrasion followed by universal adhesive (AA-UA). The specimens were bonded with relined bis-acryl resin material and left at room temperature for 24 h, allowing the complete polymerization. Then, shear bond strength was performed using a universal testing machine with a knife-edge blade parallel to the bonded surface at a crosshead speed of 1 mm/min until failure occurred. The fracture surfaces were examined under stereomicroscopy (20X) and scanning electron microscopy (50X). Results: The CT group had the lowest shear bond strength (1.92 ± 0.26 MPa), which was no statistically significant difference from ET (2.11 ± 0.23 MPa). The significantly highest shear bond strength was obtained from AA-UA (14.39 ± 1.07 MPa) (p < 0.05), followed by AA (6.39 ± 0.59 MPa) and UA (3.34 ± 0.21 MPa), respectively. Failure modes obtained were varied, with mixed and cohesive failures in AA-UA (46.6% mixed failures) and AA groups (66.6% mixed failure) whereas primarily adhesive failures were observed in CT (93.5%), ET (86.6%), and UA groups (86.6%). Conclusions: Within the limitation of this study, the optimal bond strength was obtained when airborne-particle abrasion and universal adhesive were applied on the 3D-printed provisional material and relined with bis-acryl relining material. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Aim Methods Results Conclusion Recently, the importance of peri‐implant soft tissue integration quality has been recognised as an essential factor in the long‐term success of dental implant rehabilitation.The aim of this study was to explore the influence of three materials commonly used in implant dentistry, namely titanium (Ti), dental adhesive resin (Re) and polyetheretherketone (PEEK), on the peri‐implant soft tissues.In this clinical randomised comparative study, 37 bone‐level implants were placed, and experimental transmucosal healing abutments made of different materials were randomly assigned to each implant. These abutments were removed together with the surrounding soft tissues after 8 weeks. Immunohistochemical analyses were performed to determine the presence and localisation of different immune cells. In addition, clinical and radiographic data were collected and peri‐implant bone remodeling was assessed.Compared to the Ti and PEEK groups, Re abutments revealed a higher infiltration of macrophages in the connective tissue (p = 0.04) and neutrophils in the adjacent epithelium (p = 0.03). In the Re abutments, peri‐implant bone remodeling was higher compared to the other groups (p = 0.01).The use of resin material as a transmucosal healing abutment should be carefully considered as it was associated with a higher presence of inflammatory cells at 8 weeks post‐implantation as well as superior bone remodeling compared to PEEK and Ti. [ABSTRACT FROM AUTHOR]

In the latter part of the 20th century, remarkable developments in new dental materials and technologies were achieved. However, regarding the impact of dental resin-based materials 3D-printed on cellular responses, there have been a limited number of published studies recently. The biocompatibility of dental restorative materials is a controversial topic, especially when discussing modern manufacturing technologies. Three-dimensional printing generates the release of residual monomers due to incomplete polymerization of materials and involves the use of potentially toxic substances in post-printing processes that cannot be completely eliminated. Considering the issue of biocompatibility, this article aims to establish an overview of this aspect, summarizing the different types of biocompatibility tests performed on materials used in 3D printing in dentistry. In order to create this comprehensive review, articles dealing with the issue of 3D printing in dentistry were analysed by accessing the main specialized search engines using specific keywords. Relevant data referring to types of materials used in 3DP to manufacture various dental devices, polymerization methods, factors affecting monomer release, cytotoxicity of unreacted products or post-curing treatments, and methods for assessing biocompatibility were analysed. Although the introduction of new restorative materials used in dental treatments is subject to national and international regulations and standards, it is necessary to investigate them regarding biocompatibility in order to support or deny the manufacturers' statements regarding this aspect. [ABSTRACT FROM AUTHOR]

A novel dental fiber post from glass fiber‐reinforced polybenzoxazine (PBZ) composites was developed in this work. The essential properties, that is, chemical characteristics, thermal and biological properties of the PBZ composites were investigated for various glass fiber loadings (10.5, 23.7, 41.2 and 65.1 vol%). Finite element analysis (FEA) was also utilized to observe mechanical behaviors of the tooth model repaired with PBZ composite posts compared to a natural tooth model. The findings reveal that for the fiber‐reinforced PBZ composites not only their thermal properties were significantly improved, but they also showed enhanced cytocompatibility; we found a coefficient of thermal expansion of 12.8 ppm/°C and cell viability of 91.55 for the 65.1 vol% glass fiber‐reinforced PBZ composite. Moreover, samples reinforced with higher glass fiber loadings effectively resulted in the reduction of stress distribution in dentin observed from FEA suggesting protection againt root fractures. Restoration using the PBZ composite post showed the same stress patterns in the dentin‐composite resin‐post interface of the repaired tooth as in the natural tooth model. The results revealed that the glass fiber‐reinforced PBZ composites possess good thermal properties and mechanical behaviors which renders them suitable candidates for biocompatible dental materials. Highlights: The glass fiber/polybenzoxazine (GF/PBZ) composites had nontoxic properties as evidenced through cell viability, growth and morphology studies.The thermal expansion of the GF/PBZ composite was similar to that of dentin, promoting adaptation at the dentin‐post interface.Mechanical behaviors evaluated by FEA of tooth model restored with GF/PBZ composite post were similar to those restored with commercial glass fiber post.The biocompatible GF/PBZ composite with good thermal and mechanical properties is a promising new candidate material as dental fiber post. [ABSTRACT FROM AUTHOR]

This study aims to enhance dental resins' mechanical and thermal properties by reinforcing them with Al-doped ZnO/SiO2 nano-glass ceramic. The synthesis of the nano-glass ceramic involved the addition of Al-doped ZnO nano-powders to a diluted aqueous solution of liquid glass (25 mL) in ethanol (50 mL) at room temperature. The synthesized samples were characterized using TEM, EDS, FE-SEM, and XRD techniques. Various concentrations of the nano-glass ceramic (2, 5, 8, 10, and 15 wt.%) were then integrated with Bis-GMA and TEGDMA. The mechanical properties, including flexural strength (FS), compressive strength (CS), diameter tensile strength (DTS), and flexural modulus (FM), were evaluated. Thermal stability was assessed through TGA analysis, which indicated polymer degradation occurring between 300 and 450 °C. An increase in filler content correlated with enhanced thermal stability. The optimal mechanical properties were observed at a 7.5 wt.% filler content, showing significant improvements in FS (124.652 MPa), FM (9.87GPa), DTS (33.87 MPa), and CS (178.47 MPa). [ABSTRACT FROM AUTHOR]

ABSTRACT: Objective: This study aims to assess and compare the color stability of 3D-printed, computer-aided design–computer-aided manufacturing (CAD-CAM)-milled, and conventional materials used in interim dental restorations. Materials and Methods: Sixty-four disc-shaped specimens (10 mm diameter, 1.5 mm thickness) were fabricated from four types of interim materials: autopolymerizing polymethyl methacrylate (PMMA), bis-acryl composite resin, CAD-CAM PMMA resin, and 3D-printed provisional resin. Each group of polished specimens was divided into four subgroups (n = 4) and immersed in different staining solutions (distilled water, cola, coffee, and tea) at 37°C and 100% humidity without light exposure for 1 day, 7 days, and 30 days. Color changes were measured using a calibrated clinical spectrophotometer. Results: The type of material, staining solution, immersion period, and their interactions significantly influenced color stability (P < 0.001). Bis-acryl and 3D-printed materials exhibited the most discoloration, with coffee and tea causing the highest color changes. CAD-CAM-milled and PMMA materials demonstrated superior color stability, particularly in water and cola. Conclusion: Bis-acryl and 3D-printed materials showed significant and clinically unacceptable color changes, while CAD-CAM-milled and PMMA materials maintained color stability within clinically acceptable limits (ΔE ≈ 3.3). CAD-CAM and PMMA are preferred for interim restorations where color stability is critical. [ABSTRACT FROM AUTHOR]

ABSTRACT: Background: Alginate is a widely used dental impression material in clinical settings. Despite advances in impression materials and the growing popularity of digital impression techniques, alginate remains a staple due to its ease of use and cost-effectiveness. The dimensional stability of irreversible hydrocolloid alginate is influenced by various factors, including storage temperature and the elapsed time between taking the impression and pouring the cast. Materials and Methods: This in vitro study aimed to evaluate the dimensional stability of two alginate impression materials, Cavex CA37 and Zhermack Hydrogum 5, over four different time periods. Statistical analyses, including Student's t -test, three-way ANOVA, post hoc Tukey HSD tests, and ANCOVA, were used to determine the significance of differences between groups and the impact of pouring time on dimensional stability. Results: Post hoc analysis revealed significant differences in dimensional stability between the two alginates across different time periods. For Zhermack Hydrogum 5, a significant difference (P < 0.05) was observed between the 120-hour mark and the other three time periods. Cavex CA37 exhibited significant differences (P < 0.05) between immediate pouring (0 hours) and the subsequent three time periods. Conclusion: The findings suggest that impressions made with Cavex CA37 should be poured immediately to ensure optimal dimensional stability. Conversely, Zhermack Hydrogum 5 maintains accurate dimensional stability when poured within 24 hours, making it a more flexible option in clinical practice. [ABSTRACT FROM AUTHOR]

This case report features a female patient with the chief complaint of needing to replace an anterior crown. After a comprehensive oral assessment and cone beam computed tomography (CBCT) radiographic examination, it was determined that the crown on Tooth #9 was subgingivally fractured. The procedure involved atraumatic extraction of Tooth #9, followed by immediate implant placement. Xenograft bone graft material was placed to complete the space between the buccal bone and the implant. A connective tissue graft (CTG), 1 mm thick and 5 mm wide, was harvested from the palate and placed. The final implant crown was restored using a prefabricated abutment with a titanium base and zirconia ceramic dental material. A well‐planned combined treatment, including atraumatic tooth extractions for immediate implants and ideal contouring of soft tissues, can significantly impact the outcome of aesthetic restorations. A single immediate implant‐supported crown in the aesthetic zone was able to fulfill the patient's aesthetic expectations at the 2‐year follow‐up. [ABSTRACT FROM AUTHOR]

Background/purpose: Traditional restorative composites require time-consuming incremental layering techniques which poses challenges in pediatric dentistry. SonicFill bulk resin allows for thicker layers to be placed efficiently, reducing treatment time and enhancing filling quality. This prospective, parallel, randomized, controlled clinical study aimed to compare the operative time and outcomes between SonicFill bulk resin and conventional restorative composite for deep proximal restorations in primary molars. Materials and methods: A total of 129 primary molars in patients with proximal deep caries were randomly assigned to two groups. The experimental group (n = 66) received SonicFill bulk resin treatment, while the control group (n = 63) underwent restoration using traditional composite. The operative time was documented, and all teeth were evaluated at 6, 12, 18, and 24 -months post-treatment based on the modified criteria from the United States Public Health Service and radiographic examination score. Results: The operative time for SonicFill resin (137.5 ± 5.2 s) revealed a significant reduction compared to traditional composite (193.5 ± 14.4 s), (t = 29.64, P < 0.05). No significant differences were observed between the two groups in terms of colour match, marginal adaptation and so on. Success rates were 95.2% for the control group and 89.4% for the experimental group (χ2 = 1.44, P>0.05). Conclusion: The SonicFill resin technique has proven to be a viable and time-efficient option for the restoration of primary molars with deep proximal caries. Trial registration: This study was registered in the Chinese Clinical Trial Registry (ChiCTR2200055570) on the date of 13/01/2022. [ABSTRACT FROM AUTHOR]

Water treeing and water droplets are observed within adhesive layers and on the hybridized surface after bonding sound dentin using single‐bottle etch‐and‐rinse adhesives, indicating permeability of the hybrid layer to water. The aim of this study was to assess the efficacy of dentin sealing by adhesives containing propolis by quantifying the area of water transudation from dentinal tubules after dentin hybridization. Brazilian red propolis was added to experimental adhesive and Single Bond (3M/ESPE) adhesive; experimental adhesive and Single Bond without propolis were used as controls. Under simulated pulp pressure, two layers of adhesive were applied to etched human dentin discs. Three minutes after light‐curing, the hybridized dentin surface was replicated, and epoxy resin replicas were created to obtain scanning electron microscope images. Data were evaluated using ANOVA and Tukey's test. Single Bond containing propolis significantly decreased water permeation through the hybrid layer compared with the control group. Three minutes after polymerization, the experimental adhesive without propolis had formed a permeable hybrid layer. The addition of Brazilian red propolis significantly reduced surface water on hybridized dentin in a concentration‐dependent manner. Two‐step etch‐and‐rinse adhesives containing propolis were effective in reducing water permeation through the hybridized dentin surface. [ABSTRACT FROM AUTHOR]

Access cavity preparation represents the initial step in root canal treatment. Minimally invasive approaches have gained increasing attention and involve advancements in the traditional access cavity preparation. Simultaneously, the development of three‐dimensional finite element analysis (3D‐FEA) has provided a theoretical foundation for evaluating the merits and drawbacks of various access cavity preparations. Studies using static loading 3D‐FEA have suggested that conservative access cavity preparation reduces the concentration of stress in the cervical region, thereby strengthening fracture resistance. However, the lack of support from clinical data raises concerns about the validity of this suggestion. Conversely, studies involving cyclic loading 3D‐FEA and dynamic loading 3D‐FEA have challenged the prevailing perspectives by taking into account additional factors such as filling materials, thus providing a more comprehensive understanding of the impact of access cavity preparation on fracture resistance. Existing research lacks a comprehensive comparison of the different 3D‐FEA methods, and this review fills this gap by providing a systematic assessment of different 3D‐FEA methods and their applications in access cavity preparation. [ABSTRACT FROM AUTHOR]

This study assessed the bond strength of resin‐based restorative materials to fast‐setting calcium silicate cement (Aarhus Uinversity, Denmark) when treated with each of two one‐bottle universal adhesive systems. The cement surface (N = 256) was treated with a self‐priming adhesive and a self‐etch phosphate monomer‐containing adhesive with and without etching of the cement surface. Specimens then received either resin composite or compomer restorative materials (n = 32). The bond strength was measured after 1 day and 1500 thermocycles (n = 16). The failure type was visually inspected. The cement‐adhesive‐restorative material interface was visualized using scanning electron microscopy (SEM). The data were analyzed using multiple linear regression. Restorative material type, resin adhesive system, and thermocycling had a statistically significant effect on the bond strength. Compomer restorative material and self‐etch universal adhesive system demonstrated statistically significantly higher bond strength values to fast‐setting calcium silicate cement, predominantly exhibiting cement cohesive failure. Etching the cement surface enhanced the bond strength of the self‐priming universal adhesive. Thermocycling significantly reduced the bond strength. SEM showed self‐etch universal adhesive seemingly diffused over the etched cement surface compared to other groups. Self‐etch phosphate monomer‐containing universal adhesive and compomer resulted in the highest bond strength to fast‐setting calcium silicate cement. [ABSTRACT FROM AUTHOR]

A promising approach for managing root caries is the use of cross‐linking agents to stabilize collagen. However, despite testing various natural and synthetic agents in vitro, their efficacy remains uncertain. The aim of this review was to examine which cross‐linking agent performs better in reducing root caries lesion depth and the release of hydroxyproline, which is a marker of collagen degradation. Studies evaluating the impact of cross‐linking agents on dentin were included, while studies performed on enamel surface/cell cultures and studies evaluating collagenase inhibitors were excluded, among others. A comprehensive search covered eight databases, and study quality was assessed using the QUINN Tool for in vitro dental studies. Synthesis of the results was done using a Bayesian network meta‐analysis to compare agents. Fifty studies involving 31 cross‐linking agents were included for qualitative synthesis. The network meta‐analysis for lesion depth involved 284 samples across 36 comparisons and ranked cross‐linking agents in terms of their caries lesion depth‐reducing effect (from best to worst): naringin > quercetin > riboflavin > proanthocyanidins > hesperidin > glutaraldehyde > cranberry > grape seed extract > untreated controls. Only naringin, quercetin, proanthocyanidins, and glutaraldehyde showed statistically significant efficacy over untreated controls. Cranberry extract excelled in reducing hydroxyproline release, followed by proanthocyanidins. In conclusion, proanthocyanidins positively affected both outcomes, suggesting they are prime candidates for translational research. Clinical studies are now essential to evaluate their real‐world effectiveness against root caries. PROSPERO‐CRD42023404911. [ABSTRACT FROM AUTHOR]

Objective: The present paper aims to demonstrate the incorporation of the double monolithic protocol (DMP) into a chairside digital workflow to reproduce the fluorescence properties of natural teeth with chairside monolithic restorations when exposed to different light sources. Clinical Considerations: A female patient reporting dissatisfaction with her upper anterior teeth was rehabilitated using seven veneers and a three‐element bridge. The DMP was applied to the bridge, which consisted of a primary lithium disilicate framework to which leucite‐reinforced glass ceramic veneers were cemented. The fluorescence of the different substrates and ceramic restorations was evaluated throughout the rehabilitation process, under 365 and 405 nm light. Conclusions: The DMP allows chairside procedures to be optimized by achieving predictable, mechanically resistant, and esthetic restorations. Clinical Significance: The DMP is a new chairside solution for developing ceramic restorations with optimal esthetics and combined mechanical properties, eliminating the need for sintering or glazing procedures. [ABSTRACT FROM AUTHOR]

Objective: This article aims to describe a systematic method for tooth color reproduction with ceramics restorations employing artificial intelligence (AI) software named Matisse. It provides a comprehensive analysis of the entire process, beginning with shade‐taking and extending to ceramic application in a complex clinical case in the anterior region—specifically, a single central restoration supported by an implant. Clinical Considerations: The clinical case presented highlights the potential of Matisse software for generating ceramic (inSync‐Jensen Dental, USA) and staining (Miyo‐Jensen Dental, USA) recipes over a zirconia abutment (Katana‐Noritake Dental, Japan). This approach achieves an optimal single central restoration utilizing CAD‐CAM and layering techniques. Conclusions: The systematic method employing the Matisse software achieved accurate color reproduction for a single central restoration supported by an implant. This result was achieved by the dental ceramist within the first attempt and without seeing the patient in the entire process. Clinical Significance: The Matisse AI‐assisted protocol offers a systematic and scientifically grounded method for color reproduction in dentistry for indirect restorations. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to assess the fit of interim crowns produced using DLP‐based 3D printing with different manufacturing workflows—open and proprietary—versus milling technology. Methods: A total of 120 crowns were evaluated using the replica technique. The control group (Mill, n = 30) was manufactured via subtractive technology. Experimental groups were printed using a DLP printer (SprintRay Pro95). In the proprietary mode (SR100, n = 30), manufacturer resin was used with a 100‐μm layer thickness (LT) and a splashing cleaning postprocessing. In the open mode, validated resin was used. Group B100 (n = 30) had a 100‐μm LT, and group B50 (n = 30) had a 50‐μm followed by postprocessing in an ultrasonic bath with full immersion in isopropyl alcohol. Kruskal–Wallis tests with Bonferroni correction was applied after normal analysis (α = 0.05). Results: Group B50 exhibited the best overall fit (123.87 ± 67.42 μm), which was comparable to the gold standard Milling group, which demonstrated the lowest marginal fit (p = 0.760). SR100 showed significantly poorer performance compared to Mill, B50, and B100 (p < 0.001). Conclusions: 3D printed and milled interim crowns generally demonstrated clinically acceptable fit, with the exception of the SR100 group. Postprocessing notably influenced crown fit, with the open mode with total immersion in isopropyl alcohol being superior. Clinical Significance: The present study demonstrates that the selection of an optimal manufacturing and postprocessing workflow results in superior fit for interim crowns. This enables dental professionals to evaluate protocols and ensure reliable outcomes with improved clinical outcomes in interim crown fabrication. [ABSTRACT FROM AUTHOR]

Introduction: Erbium‐doped yttrium‐aluminum‐garnet (Er:YAG) laser debonding of zirconia and lithium disilicate restorations is increasingly used for a range of clinical applications. Using rotary instruments to remove such restorations for any purpose has proven to be challenging. Erbium laser has been reported to be a conservative method for removing ceramic restorations. There is little data in the literature about the effect of adhesive resin cement type on the debonding time of the ceramic restoration using the Er:YAG laser. Objectives: To evaluate and compare the time required for the Er:YAG laser to debond zirconia and lithium disilicate crowns bonded with a 2‐ and 1‐bottle adhesive resin cement systems. Materials and Methods: Forty extracted premolar teeth were prepared and scanned for milled 40 CAD/CAM crowns. Teeth were randomly assigned into groups (n = 10 per group): 3 mol% yttria‐partially stabilized zirconia crowns 3Y‐PSZ (G1a) bonded with Panavia™ V5 (2‐bottle adhesive resin cement), Zirconia 3Y‐PSZ crowns (G1b) bonded with RelyX™ Ultimate (1‐bottle adhesive resin cement), and for the lithium disilicate crowns bonded with the two types of cements (G2a, G2b). Each specimen was irradiated with an Er:YAG laser at 335 mJ, 15 Hz, 5.0 W, and 50‐ms pulse duration (super short pulse mode). The irradiation time required for crowns to be successfully debonded was recorded for each specimen. Data were statistically analyzed using ANOVA and Tukey HSD post‐hoc test (p < 0.05), at the 95 percent level of confidence. The intaglio surface of the debonded crown was analyzed using scanning electron microscopy (SEM). Results: The mean ± standard deviation times needed for crown debonding were 5.75 ± 2.00 min for the G1a group, 4.79 ± 1.20 min for group G1b, 1.69 ± 0.49 min for group G2a, and 1.12 ± 0.17 for group G2b. There was no statistically significant difference in debonding time between the 2‐ and 1‐ bottle adhesive resin cement within the groups G1a and b (p = 0.2914), or between groups G2a b (p = 0.7116). A statistically significant difference (p < 0.05) was found between groups G1a and G2a and b and between groups G1b and G2a and b were SEM analysis showed no changes in the microstructure of the ceramic surface after Er:YAG laser irradiation. Conclusion: Zirconia and lithium disilicate restorations can be debonded using Er:YAG lasers in a safe and efficient manner. There is no significant difference in the debonding time between the 2‐ and 1‐ bottle adhesive resin cement systems used in this study. Clinical Significance: Retrieving zirconia and lithium disilicate ceramics can be a challenging process when using diamond rotary instruments. ER:YAG lasers may efficiently debond these ceramics from the tooth structure, independent of the bonding process used for bonding them. [ABSTRACT FROM AUTHOR]

Polymethyl methacrylate (PMMA) has been widely used as a material in dentistry. The deterioration of pure PMMA denture teeth is a significant issue that can alter the vertical dimensions of dentures. This study investigates the effect of aluminum oxide (Al2O3) nano-ceramic addition as reinforcements into the heat-cure acrylic resin denture teeth. The PMMA was reinforced with Al2O3 concentrations of 1, 3, 5, and 10 wt.%. The PMMA without ceramic addition is produced for comparison purposes. The color change, densification, microhardness, and compressive properties of the produced PMMA resin and its composites were investigated to detect the effect of Al2O3 nano ceramic addition on the physical and mechanical properties. Furthermore, the microstructure was also performed using scanning electron microscopy (SEM) analysis. A chewing simulator was utilized to conduct two-body wear testing, employing a human enamel antagonist. The wear behavior of the PMMA and their composites were assessed by measuring the weight loss after submitting them to 37,500 cycles. The SEM microstructure analysis revealed sound specimens of PMMA reinforced with 0, 1, 3, and 5 wt.% Al2O3 without any porosity and micro defects using the applied production procedures. In contrast, the aggregated sites and propagation of cracks were detected for the PMMA/10 wt.% Al2O3 specimen. The densification and hardness properties of the produced PMMA composites improved with increasing the Al2O3 additions. The microhardness of PMMA/10 wt.% Al2O3 improved by around 233% compared to the PMMA matrix. The higher compressive properties were detected for the PMMA/5 wt.% Al2O3 composite specimen with ultimate compressive strength (UCS) of 54.75 MPa and yield strength (YS) of 45.6 MPa and improved than the PMMA matrix by around 98 % and 117 %, respectively. In addition, incorporating Al2O3 nano-ceramic particles into a PMMA matrix revealed a significant improvement in the wear resistance of the produced composites compared to the PMMA matrix. [ABSTRACT FROM AUTHOR]

Billions of patients struggle with dental diseases every year. These mainly comprise caries and related diseases. This results in an extremely high demand for innovative, polymer composite filling materials that meet a number of dental requirements. The aim of the study was to modify the light-cured composition of permanent dental fillings by changing the composition of the liquid organic matrix. New photoinitiators (DQ1-DQ5) based on a quinoline or quinoxaline skeleton and a co-initiator-(phenylthio)acetic acid (PhTAA) were used. In addition, monomers that have been traditionally used in dental materials were replaced by trimethylolpropane triacrylate (TMPTA). The neutral dental glass IDG functioned as an inorganic filler. The influence of the storage conditions of the developed composites in solutions simulating the natural oral environment during the consumption of different meals on sorption, solubility, and mass changes was assessed. For the tests, fifty-four cylindrical composite samples were prepared according to ISO 4049 guidelines and stored in different solutions. Distilled water, artificial saliva, heptane, 10% ethanol, and 3% acetic acid, as well as solutions containing pigments such as coffee, tea, red wine, and Coca-Cola, were used for the studies. The samples were stored in these solutions for 7, 14, 28, 35, 42, 49, 56, and 63 days at 37 °C. The sorption, solubility, and mass changes in the tested samples were determined, and the trend of these changes as a function of storage time was presented. The results were analyzed considering the nature of the solution used, i.e., aqueous, hydrophobic, and acidic. The properties evaluated changed in a different way, characteristic for each of the abovementioned solution groups. It was found that the type of solution simulating the natural environment of the oral cavity has the greatest influence on the sorption, solubility, and changes in the mass of the tested material. [ABSTRACT FROM AUTHOR]

This in vitro study investigated how varying magnifications (5×, 10×, 20×, and 50×) using a confocal laser scanning microscope (CLSM) influence the measured surface roughness parameters, Ra/Sa and Rz/Sz, of various materials with two surface treatments. Cylindrical specimens (d ≈ 8 mm, h ≈ 3 mm, n = 10) from titanium, zirconia, glass-ceramic, denture base material, and composite underwent diamond treatment (80 μm; wet) and polishing (#4000; wet; Tegramin-25, Struers, G). The surface roughness parameters (Ra/Sa, Rz/Sz) were measured with a CLSM (VK-100, Keyence, J) at 5×, 10×, 20×, and 50× magnifications. Line roughness (Ra/Rz) was measured along a 1000 μm distance in three parallel lines, while area roughness (Sa/Sz) was evaluated over a 2500 μm × 1900 μm area. The statistical analysis included ANOVA, the Bonferroni post hoc test, and Pearson correlation (SPSS 29, IBM, USA; α = 0.05). Ra/Sa and Rz/Sz showed significant differences (p ≤ 0.001, ANOVA) across magnifications, with values decreasing as magnification increased, highest at 5× and lowest at 50×. Titanium, zirconia, and glass-ceramic showed significant measured roughness values from 5× to 50×. Denture base material and composite had lower measured roughness values, especially after polishing. Line and area roughness varied significantly, indicating that magnification affects measured values. Standardizing magnifications is essential to ensure comparability between studies. A 50× magnification captures more detailed profile information while masking larger defects. [ABSTRACT FROM AUTHOR]

A high level of scientific evidence supports several nonrestorative strategies for the control of caries, with the goal of reducing progression of mineral loss and arresting existing lesions. The authors provide an overview of evidence for nonrestorative caries control and considerations in the decision making for selecting nonrestorative options. The authors discuss findings from existing reviews, systematic reviews, and evidence-based guidelines (particularly from the American Dental Association) describing the effectiveness of nonrestorative strategies available in the US market for remineralization and arrest of caries lesions. Studies support a wide range of products for arresting caries lesions, such as fluorides, sealants, infiltration resins, and chlorhexidine varnish, among others, depending on the tooth surface, primary or permanent dentition, and whether lesions are noncavitated or cavitated. Decisions should be based on appropriate detection, diagnosis, and risk assessment. Effective nonrestorative strategies should be used to manage active, noncavitated caries lesions in primary and permanent teeth, and can be considered for managing active cavitated lesions when restorative intervention is not feasible. These lesion-centered interventions should be part of the required overall management of the caries disease process and existing modifiable risk variables at the patient level. They must be monitored over time and reapplied periodically, as needed. [ABSTRACT FROM AUTHOR]

To review the published evidence for the role of cross-head speed on the apparent mechanical properties and bond strength of filled resins to tooth structure in order to identify the causes of inconsistency and contradictory results. The data for all available mechanical test results for studies involving dental resins at more than one strain rate was collected from 22 papers. Statistical reanalysis using linear regression was used to test the hypothesis that cross-head speed was correlated with the outcome, with the implication of causality, in each case. In many cases the expected trend was found, in others not. However, it was apparent that the quality of data was often less than can be achieved, and that known interferences have not been recognized. Experimental work for the effect of cross-head speed on bond strength and other properties for dental resin-based materials has often failed to reach the standard which is required for useful data and thus better comprehension of behaviour. Other relevant conditions, such as temperature and water saturation, are in need of attention in this context. [ABSTRACT FROM AUTHOR]

The biocompatibility of dental materials is critical for ensuring safety in clinical applications. However, standard in vitro cytotoxicity assays often rely on stiff tissue culture plastic (TCP), which does not accurately replicate the biomechanical properties of soft oral tissues. In this study, we compared human gingival fibroblasts (HGFs) cultured on soft, gel-based substrates mimicking gingival tissue stiffness (0.2 kPa) with those cultured on conventional TCP (3 GPa) to assess the influence of substrate stiffness on the cytotoxicity of methyl methacrylate (MMA), as well as other cytotoxic agents, including DMSO and H2O2. The results demonstrated that cells cultured on softer substrates exhibited enhanced resistance to cytotoxic stress, with increased viability and decreased apoptosis and DNA damage following exposure to MMA, DMSO, and H2O2. Notably, HGFs on soft substrates showed significantly greater resilience to MMA-induced cytotoxicity compared to those cultured on TCP. These findings emphasize the critical role of substrate stiffness in modulating cellular responses to toxic agents and highlight the necessity of using physiologically relevant models for cytotoxicity testing of dental materials. This study provides valuable insights for improving biocompatibility assessment protocols in clinical settings. [ABSTRACT FROM AUTHOR]

This systematic review evaluated the effect of different hydrofluoric acid (HF) etching regimens and a self-etch ceramic primer (SECP) on the flexural strength (FS) and fatigue failure load (FFL) of glass-ceramic materials.The identification of relevant studies was conducted by two authors in five databases: PubMED, Scopus, Web Of Science, LILACS and Virtual Health Library (BVS) until July 2022 with no year limit. The analysis was conducted in RevMan 5.4.1 Software (Cochrane Collaboration) using Random effect model at 5 %. The risk of bias of the included studies were assessed. From the 5349 articles identified, 34 were included for quantitative analysis. Meta-analysis showed that for predominantly glassy ceramics, etching with HF 5 % had no significant impact on FS, however, HF acid etching with concentrations greater than 5 % negatively impacted FS. For lithium disilicate glass-ceramics (LDGC) HF acid etching, negatively influenced FS, while increasing the FFL. HF etching negatively affected FS of hybrid ceramics. The self-etch ceramic primer and HF acid etching showed a similar impact on FFL and FS. This meta-analysis indicates that the impact of SECP and HF acid etching on the mechanical behavior of glass ceramics is material-dependent. [ABSTRACT FROM AUTHOR]

Statement of the Problem: Dentin adhesion is challenging and needs modifications. Newly introduced nature-derived materials may be a useful solution in improving dentin adhesion. The use of natural antimicrobial agents for pretreating prepared dentin surfaces before restoration has become of interest. Purpose: The present study investigated the effect of natural compounds on the shear bond strength (SBS) of resin composite adhesively bonded to dentin. Materials and Method: Sixty extracted human molar teeth were randomly divided into six groups (n= 10); Group I: two-step etch and rinse adhesive system, Adper Single Bond 2 (SB2) (experimental control), Group II: 2.5% Chitosan+etch+SB2, Group III: 15% Neem (Azadirachta indica)+etch+SB2, Group IV: 15% Tulsi (Ocimum sanctum)+etch+SB2, Group V: 2% Aloe vera+etch+SB2, and group VI: 2% Chlorhexidine (CHX)+etch+SB2. Resin composite (Z350, 3M ESPE USA) was placed over the prepared dentin surfaces and was light cured. Data analysis was performed using One-way ANOVA and post hoc Tukey's test (p< 0.05). Results: Neem specimens showed the highest mean SBS, statistically greater than the control (p= 0.042). Other experimental groups showed no significant differences in SBS comparison to the control. The mean SBS values of 2.5% Chitosan, 15% Neem, 15% Tulsi, and 2% Aloe vera were significantly higher than 2% CHX (p= 0.046, p= 0.001, p= 0.010 and p =0.002 respectively). Conclusion: Dentin pretreatment with Neem may improve the bond strength of a two-step etch and rinse adhesive system. The application of Chitosan, Tulsi, Aloe vera, and CHX did not demonstrate significantly different SBS values from that of the Control, although CHX was lower. [ABSTRACT FROM AUTHOR]

Statement of the Problem: The creation of a proper seal of the root canal with canal-filling materials, such as gutta-percha and sealer, is one of the essential factors in the success of root canal treatment. In addition, the penetration depth of the sealer is one of the influential factors in creating a proper seal, which improves the sealing ability of the canal and the burial of microorganisms. Purpose: This study aimed to investigate the effect of cold atmospheric plasma on the depth of tubular penetration of two types of resin sealer: AH26 and Beta RCS sealers. Materials and Method: In this experimental study, thirty-two premolar teeth with single root and single canal were selected as samples and after cutting their crowns from the apex distance of 15mm, the canals were prepared with rotary files. Samples were divided into four groups of eight, according to the type of sealer and plasma application: AH26 sealer (AH), plasma+AH26 sealer (PAH), Beta RCS sealer (Beta), and plasma+Beta RCS sealer (PBeta). The cold lateral condensation technique was used for the obturation of canals. The maximum penetration depth and the percentage of sealer penetration were obtained from microscopic images at three coronal, middle, and apical sections. Due to the non-normal distribution of data, the Mann-Whitney U test was used for statistical analysis (p< 0.05). Results: No significant difference was observed between the study groups in the penetration percentage and maximum penetration depth of AH and Beta in the presence and absence of plasma. However, in the coronal section, the depth of maximum sealer penetration was significantly higher in the AH group than in the Beta group (p< 0.05). Conclusion: The use of plasma did not affect the maximum penetration depth and penetration percentage of AH26 sealer and Beta RCS sealer. [ABSTRACT FROM AUTHOR]

Ceramic is a commonly used material in dentistry for reconstructing missing teeth or their tissues due to its biocompatibility, durability and excellent esthetic properties. Despite these advantages, the ceramic restoration damage remains a significant clinical problem. Its causes can be divided into clinical and laboratory factors. The most known include uneven occlusion, improper preparation, trauma, or parafunctions. This study focuses on characterizing less known laboratory causes of ceramic restoration damage. We reviewed the current literature available in the PubMed and Scopus databases. On the basis of 63 selected studies, 3 basic causes of damage were identified: excessive stresses between the framework and ceramic veneering, poor quality of the connection between the facing layer and the substructure, and defects resulting from the nature of the ceramic material such as defects in the ceramic layer, brittleness and lack of flexibility. The stages of the manufacturing process of various permanent ceramic restorations were presented. By controlling these procedures, we can eliminate the errors, resulting in long-term effective functioning of the ceramic restorations. [ABSTRACT FROM AUTHOR]

Polymethyl methacrylate (PMMA) has been widely used as a material in dentistry. The deterioration of pure PMMA denture teeth is a significant issue that can alter the vertical dimensions of dentures. This study investigates the effect of aluminum oxide (Al2O3) nano-ceramic addition as reinforcements into the heat-cure acrylic resin denture teeth. The PMMA was reinforced with Al2O3 concentrations of 1, 3, 5, and 10 wt.%. The PMMA without ceramic addition is produced for comparison purposes. The color change, densification, microhardness, and compressive properties of the produced PMMA resin and its composites were investigated to detect the effect of Al2O3 nano ceramic addition on the physical and mechanical properties. Furthermore, the microstructure was also performed using scanning electron microscopy (SEM) analysis. A chewing simulator was utilized to conduct two-body wear testing, employing a human enamel antagonist. The wear behavior of the PMMA and their composites were assessed by measuring the weight loss after submitting them to 37,500 cycles. The SEM microstructure analysis revealed sound specimens of PMMA reinforced with 0, 1, 3, and 5 wt.% Al2O3 without any porosity and micro defects using the applied production procedures. In contrast, the aggregated sites and propagation of cracks were detected for the PMMA/10 wt.% Al2O3 specimen. The densification and hardness properties of the produced PMMA composites improved with increasing the Al2O3 additions. The microhardness of PMMA/10 wt.% Al2O3 improved by around 233% compared to the PMMA matrix. The higher compressive properties were detected for the PMMA/5 wt.% Al2O3 composite specimen with ultimate compressive strength (UCS) of 54.75 MPa and yield strength (YS) of 45.6 MPa and improved than the PMMA matrix by around 98 % and 117 %, respectively. In addition, incorporating Al2O3 nano-ceramic particles into a PMMA matrix revealed a significant improvement in the wear resistance of the produced composites compared to the PMMA matrix. [ABSTRACT FROM AUTHOR]

Aims: GBR membranes have various surface properties designed to elicit positive responses in regenerative clinical procedures; dental clinicians attempt to employ techniques to prevent the direct interaction of contaminated oral fluids with these biomaterials. However, saliva is uninterruptedly exhibited in oral surgical procedures applying GBR membranes, suggesting a persistent interaction with biomaterials and the surrounding oral tissues. This fundamental study aimed to investigate potential alterations in the physical, chemical, and key biological properties of membranes for guided bone regeneration (GBR) caused by isolated early interaction with human saliva. Methods: A reproducible step‐by‐step protocol for collecting and interacting human saliva with membranes was developed. Subsequently, membranes were evaluated for their physicochemical properties, protein quantification, DNA, and 16S rRNA levels viability of two different cell lines at 1 and 7 days, and ALP activity. Non‐interacted membranes and pure saliva of donors were applied as controls. Results: Qualitative morphological alterations were noticed; DNA extraction and 16S quantification revealed significantly higher values. Furthermore, the viability of HGF‐1 and MC3T3‐E1 cells was significantly (p <.05) reduced following saliva interaction with biodegradable membranes. Saliva contamination did not prejudice PTFE membranes significantly in any biological assay. Conclusions: These outcomes demonstrated a susceptible response of biodegradable membranes to isolated early human saliva interaction, suggesting impairment of structural morphology, reduced viability to HGF‐1 and MC3T3‐E1, and higher absorption/adherence of DNA/16S rRNA. As a result, clinical oral procedures may need corresponding refinements. [ABSTRACT FROM AUTHOR]

Purpose: To assess the repeatability of various color‐measuring mobile phone applications (MPAs) on dental materials in clinically relevant shades in 1‐mm thickness. Materials and Methods: A benchtop spectrophotometer was used as a reference instrument. Seven MPAs were used: Color Analysis, Color Analyzer—Iro Shirabe, Color Grab, and Colorimeter from Android, and Color Analyzer—Iro Shirabe, ColorMeter RGB, and Optishade from iOS. Color measurements were performed on 1‐mm thickness slices of CAD‐CAM materials, Vita Enamic shades 1M2, 2M2, 3M2, 4M2, and Vitablocs Mark II shades A1C, A2C, A3C, A4C (n = 10, for a total 80 specimens). The specimens were measured at three time periods, Day 0, Day 1, and Day 7, and three measurements were made on each day, to mimic short‐, medium‐, and long‐term repeatability. The color differences were analyzed using the CIEDE2000 formula, with the corresponding color difference (ΔE00), and mean color difference from the mean (MCDM00). One‐way ANOVA, Repeated measures ANOVA, and Paired sample t‐tests were used for statistical analysis. Results: Optishade from iOS showed the lowest mean color difference among the MPAs (ΔE00 = 0.2 (SD 0.1), 0.3 (SD 0.2), and 0.2 (SD 0.1) at Day 0, 1, and 7, respectively, and ΔE00 = 0.5 (SD 0.3) for all three periods Days 0–1, 0–7, and 1–7). Material‐dependent variations in the repeatability of color measurements were observed. Conclusion: There was a statistically significant difference among color measurements using MPAs and a spectrophotometer, among the MPAs, and materials. The spectrophotometer exhibited the highest repeatability across the tested time periods. The iOS Optishade showed the highest repeatability among the MPAs. [ABSTRACT FROM AUTHOR]

The effects of Easydo Activator (EA), a new sonic irrigation system, on sealer penetration at the root apex were compared to needle irrigation (NI) and passive ultrasonic irrigation (PUI) in this study. Forty-two single-rooted teeth were prepared and randomly divided into three groups (n = 14): group 1: NI; group 2: PUI; and group 3: EA. A solution of 3% sodium hypochlorite (NaOCl) was used for irrigation. Nine teeth in each group were filled with AH Plus sealer mixed with CY5 fluorescent dye and a single gutta-percha cone. The sealer penetration area, maximum penetration depth and percentage of sealer penetration at 5 mm and 1 mm from the apex were analyzed by confocal laser scanning microscopy (CLSM). The remaining 5 teeth in each group were subjected to test smear layer scores by scanning electron microscopy (SEM). The CLSM evaluation showed that increases in the area, depth and percentage of sealer penetration were detected at 1 and 5 mm from the root apex in the PUI group compared with the NI group, and greater increases were observed in the EA group (P < 0.05). The SEM experiment showed that the lowest scores for the smear layer and debris removal were achieved by the EA group when compared with the PUI and NI groups (P < 0.05). In conclusion, EA was superior to PUI and NI regarding sealer penetration at the root apex during endodontic treatment, and it could provide a new technical idea for clinical root canal therapy. [ABSTRACT FROM AUTHOR]

Objectives: Understanding human tooth structure fluorescence aids clinical and forensic dentistry, enabling tissue/material differentiation and the creation of esthetic restorative materials. Material manufacturers seek to replicate natural tooth fluorescence, necessitating the development of novel techniques to detect them. Procuring human teeth for research is challenging due to ethical and infection control standards, prompting a search for alternative models. Material and Methods: This study compares visible light‐induced fluorescence of porcine and human teeth to assess the value of porcine teeth as human analogs. Using a pulsed laser, an optimal fluorescence‐inducing wavelength was determined, followed by comparing fluorescence spectra between species. Results: Luminescence sensitivity and lifetimes were comparable between species, but spectral geometry differed. Conclusion: Porcine teeth, commonly used for dental material investigations, may not be suitable for dental fluorescence studies due to spectral differences. Accurately mimicking human tooth fluorescence remains complex. Further research is needed to develop reliable alternatives for dental fluorescence investigations that will advance clinical and forensic dentistry. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to evaluate the periodontal condition adjacent to Cention N (CN) restorations applied for noncarious cervical lesions (NCCL) compared with resin‐modified glass ionomer cement (RM‐GIC) restorations in terms of plaque accumulation, attachment loss, and gingival inflammation. Materials and Methods: This is a double‐blind split‐mouth three‐armed randomized‐controlled clinical trial. The study arms are RM‐GIC (FUJI II LC), CN + adhesive system, and CN + retentive groove. The study included 25 restorations per arm. Follow‐ups were performed at 1 week, 3, 6, and 9 months after the application of the restorations. The periodontal condition was evaluated using the plaque index (PI), the bleeding on probing index (BOP), and the probing depth (PD). Appropriate tests were used to perform statistical analyses (α = 0.05). Results: There was no significant difference between Cention N and RM‐GIC regarding the studied variables. However, after the application of the restorations, it was noted that the PI and the PD mean values increased. The average increase after 9 months was 0.06 and 0.34 for PI and PD, respectively, with that of PD being significant. It was also noted that the percentage of positive BOP sites increased at the 1‐week follow‐up for all study groups and afterward dropped to near preintervention values at the 3‐month and later follow‐ups. Conclusions: The two ion‐releasing materials Cention N and RM‐GIC have a comparable and clinically acceptable effect on the gingival tissue when restoring NCCLs. The combined effect of the gingival retraction cord and the rubber dam clamp on the periodontal tissues might be more important to consider, especially in relation to the probing depth. Future long‐term studies are needed to evaluate the effect of Cention N on the subgingival biofilm in comparison with nonion‐releasing restorative materials, and subsequently, its effect on gingival inflammation. Clinical Trial Registration: This clinical trial was registered in clinicaltrial.gov clinical registry under protocol #NCT05593159. [ABSTRACT FROM AUTHOR]

Introduction: No study has assessed the effects of nanosilica within polymethyl methacrylate (PMMA) resin and environmental pH on resin's fracture resistance and moisture absorption. Methods: A total of 90 specimens were divided into 30 subgroups of three, as per the ASTM D5045 standard: five groups of nanosilica percentages (0%/2%/5%/7%/10%), each ‎divided into six subgroups of pH levels (pH = 5/6/7/8/9, + "dry" control). The specimens were prepared by mixing silica nanoparticles with PMMA powder in a vacuum mixer. Then, the specimens were mixed with a diluent liquid (TEGDMA) according to the manufacturer's instructions. For each of the five weight percentages, 36 samples were produced. The 18 specimens in each group were randomly divided into six subgroups of pH levels. The specimens were kept in containers of liquid at different pH levels at room temperature for 1 week. Their before‐ and after‐storage weights were recorded to calculate moisture absorption. The fracture resistance test was performed (ASTM D5045 standard) using the three‐point bending method. Scanning electron microscopy was performed. Data were analyzed. Results: Both nanosilica extents and pH levels significantly affected the fracture toughness with a significant interaction (p < ‎‎0.00001). All post hoc comparisons of different pH levels (except pH= 5 vs. 6) were significant (p < ‎‎0.0001). All post hoc comparisons of different nanosilica concentrations were significant (p < ‎‎0.0001). Both nanosilica extents and pH levels significantly influenced the fracture toughness with a significant interaction (p < ‎‎0.00001). All post hoc comparisons of different pH levels and also between different nanosilica concentrations were significant (p < ‎‎0.0001). The correlation between moisture absorption and fracture toughness was significant (R = −0.382, p = 0.0009). Conclusions: Fracture toughness decreases when placed in humid and acidic environments. Also, the samples that were placed in a humid environment suffered a brittle fracture. Increasing silica nanoparticles improved fracture toughness (becoming optimal at 5 wt% nanosilica). Objective and Materials: The objective of this study was to investigate the fracture toughness of dental samples made of PMMA reinforced with various percentages of nanosilica at various pH levels. For this purpose, dental resins with various amounts of nanosilica were placed in moist media at different pH values ranging from 5 to 9 (mimicking the normal pH range of the human mouth). [ABSTRACT FROM AUTHOR]