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The aim of this study is to determine the cytotoxicity of three different nano composite resins (CRs) on human gingival fibroblast (hGF) and periodontal ligament fibroblast (hPDLF) cell lines. These CRs selected were nanohybrid organic monomer-based Admira Fusion (AF), nanohybrid Bis-(acryloyloxymethyl) tricyclo 5.2.1.0.sup.2,6 decane-based Charisma Topaz (CT), and supra nano filled resin-based Estelite Quick Sigma (EQS). MTT assay was performed to assess the cytotoxicity of CRs at 24 h and one week. AF and EQS applied on hGF cells at 24 h and one week demonstrated similar cytotoxic outcomes. Cytotoxicity of CT on hGF cells at one week was higher than 24 h (p = 0.04). Cytotoxicity of CT on hGF cells was higher at 24 h (p = 0.002) and one week (p = 0.009) compared to control. All composites showed higher cytotoxicity on hPDLF cells at one week than the 24 h (AF; p = 0.02, CT; p = 0.02, EQS; p = 0.04). AF and EQS demonstrated lower cytotoxicity on hPDLF cells than the control group at 24 h (AF; p = 0.01, EQS; p = 0.001). CT was found more cytotoxic on hPDLF cells than the control (p = 0.01) and EQS group (p = 0.008) at one week. The cytotoxicity of CRs on hGF and hPDLF cells vary, according to the type of composites, cell types, and exposure time.

Abstract Aim This in-vitro study aimed to evaluate the degree of conversion (DC) of dual-cured luting cement (Bifix QM, VOCO) and flowable composite (Grandio Flow, VOCO) under lithium disilicate glass-ceramic (IPS e.max CAD, Ivoclar Vivadent) and hybrid ceramic (Grandio Blocs, VOCO; Cerasmart, GC) CAD-CAM blocks with different thicknesses. Materials and methods Contrast ratio (CR), translucency (TPab, TP00), and opalescence (OP) parameters of 30 disc-shaped CAD-CAM blocks (n = 5) prepared with two different thicknesses (1.5 and 2 mm) and 8 mm diameters were calculated using a spectrophotometer (VITA Easyshade V, Zahnfabrik). A total of 36 Bifix QM and Grandio Flow samples were prepared at 100 μm thickness using a specific setup by polymerizing from the top of the blocks. Following immersion in distilled water at 37 °C for 24 h, luting materials were examined by Fourier Transform Infrared Spectroscopy for DC calculation. Data were analyzed using One-way ANOVA, Kruskal Wallis, Mann Whitney U, and Independent Samples t-tests (p 0.05). DC of Grandio Flow was significantly higher than Bifix QM under 2 mm-IPS e.max CAD (p = 0.011). Conclusion The translucency of the CAD-CAM blocks varies depending on their thickness. However, there was no significant difference in the DC of the luting materials depending on the block thickness. Further studies are needed on the use of flowable resin composites as luting material.

Abstract Aim This study aimed to evaluate the effect of the use of remineralization agents before the application of resin infiltration on the treatment of initial enamel lesions. Materials and methods Eighty buccal enamel samples were prepared from human molars, and artificial initial lesions were formed after 96 h of incubation with a demineralizing solution. The samples were randomly divided into 8 groups (n = 10) including a remineralizing agent (Tooth Mousse, Medical Mineral Gel, Remin Pro), resin infiltration (ICON), and a combined treatment of both. Remineralizing agents were applied in pH cycle for 7 days. Baseline, demineralization, and after-treatment fluorescence (FluoreCam and DIAGNOdent Pen), surface microhardness (HMV-2T), surface roughness (M300C), OCT (Maestro-2) and ultrasonic system (Novascope 4500) data were obtained for all groups. The sample surfaces were examined under SEM/EDX (SU3500) at x1000. Data were statistically analyzed using the Two-Way Robust ANOVA and Bonferroni tests (p

Purpose: The aim of this in vitro study was to evaluate the effect of material selection and chlorhexidine digluconate (CHX) pretreatment on microleakage in Class V cavities restored with 3 different restorative materials.Materials and Methods: Thirty freshly extracted sound human molars were cleaned and stored in distilled water. Sixty standard Class V cavities were prepared on gingival 1/3 of buccal and lingual surfaces of each tooth. Teeth were randomly assigned into 3 groups corresponding to the selected restorative material (Fuji II LC Capsule/FC, GC; Beautifil Flow Plus/BF, Shofu; and GrandioSo Flow/GF, VOCO). Lingual cavities were pre-treated with CHX (Cavity Cleanser, Bisco). The cavities were restored according to manufacturer's instructions using the materials' own adhesive systems. Teeth were stored in distilled water (24°C) for 6 months for aging. Specimens were immersed in 2% methylene blue solution for 1 h and sectioned longitudinally in buccolingual direction. Occlusal/gingival margins were examined for dye penetration and scored under x8 and x20 magnification using stereomicroscope (Leica MZ7.5, Leica Microsystems). Statistical analysis was performed using chi-square test with a significance level of p0.05). There was no statistically significant difference between the amount of microleakage of GF, FC and BF restorations in CHX-treated and untreated cavities (p>0.05).Conclusion: Application of CHX as cavity cleaner could not prevent dye penetration in Class V cavities restored with giomer, glass ionomer, and resin composites.Key Words: Chlorhexidine gluconate, composite resin, glass ionomer, microleakage.

Purpose: This clinical study aimed to evaluate the color measurement ability of intraoral scanners (Trios 3, (3Shape, Copenhagen, Denmark) and Cerec Omnicam, (Dentsply Sirona, Charlotte, NC, USA) in comparison to VITA Classical and VITA 3D-Master shades obtained by a spectrophotometer (Easyshade V, VITA, Zahnfabrik, Bad Säckingen, Germany)., Methods: Four hundred eighty teeth from thirty patients were included in the study. Fifteen patients had never undergone bleaching, and the other fifteen had undergone professional bleaching within the last 6 months. VITA Classical and VITA 3D Master shades were determined using Trios 3 (T3), Cerec Omnicam (CO), and EasyShade V from cervical, middle, and incisal/occlusal areas of maxillary and mandibular central and lateral incisors, canines, and first premolars. Color accuracy rates (cAR) were assessed by categorizing the color data according to the Munsell color system for bleached and unbleached teeth, maxillary and mandibular, and teeth arranged from anterior to posterior in each quadrant. McNemar, Mann-Whitney U, and Wilcoxon tests and Point Biserial Correlation Analysis were used for statistical analysis (significance level α=0.050)., Results: The bleached teeth had a significantly higher cAR for T3 in VITA 3D Master and VITA Classical guides (p<0.05). The cAR of the incisal area in VITA 3D Master was significantly lower in both scanners (p<0.05) except for the lightness/hue/chroma of bleached teeth. T3 cAR increased statistically significantly from anterior to posterior (p<0.001); however, no significant difference was found for CO (p=0.482)., Conclusion: The color accuracy rates of both scanners for shade guides that included all color components in this study were below 30%, which was not clinically satisfactory for color measurement. Confirming the measurements with a spectrophotometer is recommended., (©Operative Dentistry, 2024.)

Dental fluorosis (DF) is a specific esthetic issue characterized by a persistent condition in which there is a disruption in enamel development, leading to the formation of hypomineralized enamel. The resulting unusual appearance varies in intensity, presenting as mildly white and opaque to dark brown, and significantly impacts individuals' esthetic features and self-confidence. The objective of this case report was to assess the efficacy of microabrasion, dental whitening, and resin infiltration in terms of resolving lesions, tracking the sensitivity of teeth, and evaluating patient satisfaction over a period of time. A minimally invasive treatment approach in a 27-year-old woman with severe DF is detailed. The treatment plan involved enamel microabrasion, in-office bleaching, and two weeks of at-home bleaching, followed by resin infiltration for the affected tooth under rubber dam isolation. After a 5-year follow-up, the assessment of the patient's esthetic appearance indicated a successful treatment of teeth affected by DF., (©Operative Dentistry, 2024.)

Objectives: The initial shade of a resin-based restorative material should be the same as that after polymerization. In this study, the color changes of translucent and opaque composites from nine different brands were assessed after polymerization using a spectrophotometer and cross-polarization (CP) photography., Methods and Materials: Thirteen nano-hybrid (Essentia LE, GC Corp; Ceram.x Duo SphereTEC A2E/A2D, Dentsply Sirona; Harmonize A2E/A2D, Kerr Dental; IPS Empress Direct A2E/A2D, Ivoclar Vivadent; Mosaic EN/A2, Ultradent Products; Clearfil Majesty Es-2 A2E/A2D, Kuraray Noritake; Charisma Topaz A2/OL, Kulzer), two supra nano-hybrid (Estelite Asteria NE/A2B; Tokuyama), two nano-filled (Filtek Ultimate A2E/A2D; 3M) light-curing resin composites, and one micro-hybrid (Essentia MD, GC Corp) light-curing resin composite were tested. Disc-shaped specimens (n=5) were prepared using silicone molds (12 × 5 mm) and polymerized from both sides using an LED curing light (Elipar Deepcure S, 3M) at a light intensity of 1470 mW/cm2. Measurements were performed before and 1 day after polymerization using a contact-type dental spectrophotometer (Easy Shade 5, VITA Zahnfabrik, Bad Säckingen, Germany) and a combination of CP photography and Photoshop CC software (Adobe Inc, San Jose, CA, USA). Spectrophotometry and CP photography ΔE* values were calculated; the perceptibility threshold was a ΔE* value of 1.2. VITA spectrophotometry color change scores were also calculated and evaluated., Results: The overall ΔE* values ranged between 0.34 and 12.56. Two-way analysis of variance (ANOVA) showed that color change was associated most strongly with composite brand (p<0.001), followed by shade (p=0.002). Color change (p=0.002) and degree of darkening/lightening (p<0.001) were significantly greater for dentin compared to enamel shades. Clearfil Majesty Es-2 (Kuraray Noritake) showed significant lightening, whereas all other composites showed darkening after polymerization. All composite brands presented perceptible (ΔE*≥1.2) color changes. Estelite Asteria (Tokuyama), Ceram.x Duo SphereTEC (Dentsply Sirona), and Harmonize (Kerr Dental) were considered the most reliable brands regardless of the shade. The spectrophotometry and CP photography methods were positively correlated (p<0.001). Also, CIEDE2000 and CIELCH (also referred to as CIE L*c*h) color systems were positively correlated based on the ΔE* values (p<0.001)., Conclusions: Despite improvements in the chemical composition of, and fillers for, contemporary resin-based composites (RBCs), all tested composite brands showed perceptible color change after polymerization, except for some shades. Under the conditions in this study, it is preferable to polymerize the composite during the trial phase, before identifying the most appropriate shade. CP photography in combination with Photoshop analysis appears to be a reliable and promising approach for color evaluation., (©Operative Dentistry, 2022.)