Comparison of the Surface Properties of 3D-printed Permanent Restorative Resins and Resin-based CAD/CAM Blocks.

OBJECTIVE: This study aimed to investigate the surface roughness, microhardness, and color changes of resin-based computer-aided design/computer-aided manufacturing (CAD/CAM) blocks and 3D-printed permanent resins in different beverages. METHODS AND MATERIALS: Resin-based CAD/CAM blocks (Cerasmart 270 and Grandio Blocs) and 3D-printed permanent restorative resins (Crowntec and Permanent Crown) were used in this study. A total of 96 specimens were prepared from CAD/CAM blocks and 3D-printed permanent resins. The initial surface roughness, microhardness, and shade value of the specimens were measured. Then, the specimens prepared from each material were divided into three subgroups (n=8) and immersed in tea, coffee, and distilled water for 30 days. After the specimens were immersed in the beverages, the surface roughness, microhardness, and tone values were measured again. The data were statistically analyzed using a two-way analysis of variance test (p<0.05). RESULTS: No statistically significant difference was found in the surface roughness values of the resin-based CAD/CAM blocks and 3D-printed resins (p<0.05). Resin-based CAD/CAM blocks showed statistically significantly higher microhardness than 3D-printed permanent resins (p<0.05). Although the color changes in 3D-printed resins in tea and coffee were similar to those in resin-based CAD/CAM blocks on the first and seventh days, more color changes appeared in the 3D-printed resins after 30 days. The surface roughness and microhardness values of the specimens submerged in tea, coffee, and distilled water showed no statistically significant changes (p<0.05). CONCLUSIONS: Although the surface roughness of 3D-printed permanent resins was similar to that of resin-based CAD/CAM blocks, they had a lower microhardness value. Moreover, 3D-printed permanent resins showed more color changes in tea and coffee.

Resistance of Single-shade Composites to Discoloration.

The aim of this study was to examine the color change of single-shade resin composites, which can be used for all tooth shades. In this study, samples were prepared using resin composites with single-shade (Omnichroma, Vitra Unique) and multishade composite systems (G-aenial A'Chord, Clearfil Majesty ES-2 Premium). The initial color values were measured with a spectrophotometer. Then, samples were kept in wine, coffee, black tea, and distilled water and color measurements were made after days 1, 7, and 30. Color change (ΔE00) and whiteness index (WID) values were statistically analyzed using a one-way analysis of variance (ANOVA) test (α=0.05). Single-shade resin composites showed more color change from wine, coffee, and black tea than multishade resin composites (p<0.001). Single-shade composites have a greater discoloration potential. Single-shade resin composites may show more color change from beverages than multishade resin composites, which may negatively affect clinical success.

Evaluation of the cytotoxicity of contemporary glass-ionomer cements on mouse fibroblasts and human dental pulp cells.

PURPOSE: This study aimed to evaluate the cytotoxic effects of different types of contemporary GICs on human dental pulp cell (hDPCs) and mouse fibroblast (L929) cultures. METHODS: Three high-viscosity GICs (HVGIC; GC Equia Forte, Riva Self Cure, IonoStar Plus), three resin-modified GICs (RMGIC; Photac Fil, Riva Light Cure, Ionolux), and a metal-reinforced GIC (MRGIC; Riva Silver) were investigated. Twelve disc-shaped specimens of each material were prepared and stored in Dulbecco's modified Eagle medium (DMEM). L929 fibroblasts and DPCs were then cultured in 96-well plates. Uncultured DMEM was used as a negative control. Mitochondrial dehydrogenase activity (MTT) assays were performed to detect cell viability after 24, 48, and 72 h. Data were analysed using Mann-Whitney U and Friedman tests followed by a Bonferroni-corrected Wilcoxon signed rank test, with the statistical significance set at P < 0.05. RESULTS: Toxicity levels varied between the cell-culture systems. MTT assays of L929 cells showed significant differences in percentages of viable cells, as follows: Riva Self Cure = Riva Silver > GC Equia Forte > IonoStar Plus = Riva Light Cure = Photac Fil > Ionolux. MTT assays of DPCs showed the percentages of viable cells to be significantly lower for the Ionolux group when compared to the other GICs, which did not differ significantly from one another. With the exception of Ionolux, none of the other GICs tested showed any toxicity, and in fact, they all induced cell proliferation (> 100% cell viability). CONCLUSIONS: Although the degree of toxicity varied between the two cell-culture systems investigated, all the GICs tested, with the exception of Ionolux, performed favorably with regard to cytotoxicity (> 100% cell viability in both cell systems).

Association of Toll-like receptors 2, 3, and 4 genes polymorphisms with periapical pathosis risk.

BACKGROUND: The aim of this study was to investigate the role of gene variations of Toll-like receptors (TLR) 2, 3, and 4 on genetic susceptibility to periapical pathosis. MATERIAL AND METHODS: One hundred patients were included in the study and divided into two groups as follows; Control Group (n=50) that have root canal treatment and no periapical lesion, Patient Group (n=50) that have root canal treatment and periapical lesion. TLR2 Arg753Gln, TLR3 (c.1377C/T) and TLR4 Asp299Gly and Thr399Ile polymorphisms were genotyped by using PCR-RFLP. Genotypical analysis of control and patient groups were investigated to disclose whether there is any association between periapical lesions and gene variations. RESULTS: There are no significant statistical differences between control and patient groups according to TLR 2 and 4 gene sequence. On the contrary, CC allele detected 74% for TLR 3 in patient group, and this difference was found to be statistically significant (p < 0.005). CONCLUSIONS: According to these results, it can be suggested that patients with Toll-like receptor 3 gene polymorphisms could be susceptible to periapical pathosis.

Dynamic assessment of Capparis spinosa buds on survival of periodontal ligament cells using a real-time cell analysis method.

BACKGROUND: Tooth avulsion is the most severe type of traumatic dental injuries and it results in the complete displacement of the tooth out of its socket in alveolar bone. Reimplantation of the tooth is considered to be a best treatment modality due to its biological and psychological advantages. Its prognosis depends on the extra alveolar time, the storage medium, and the patient's general health. OBJECTIVE: The aim of this study was to evaluate the effect of Capparis spinosa (C. spinosa) in maintaining the viability of human periodontal ligament (PDL) cells using a real-time cell analysis method. MATERIALS AND METHODS: Periodontal ligament cells were obtained from healthy human third molars extracted for orthodontic purposes. The storage media tested were: Dulbecco's Modified Eagle Medium (DMEM), C. spinosa, Hank's Balanced Salt Solution (HBSS), and light milk. A real-time cell analyzer system was used to evaluate cell viability. After seeding cell suspensions into the wells of the E-plate 96, PDL cells were treated with each of tested media and monitored for every 5 min for 26 h. Statistical analysis of the data was accomplished using one-way analysis of variance complemented by the Tukey test. The level of significance was set at P < 0.05. RESULTS: Dulbecco's Modified Eagle Medium (control) and C. spinosa groups had significantly higher cell index values compared with the HBSS and light milk (P < 0.05). Although, C. spinosa showed better results than DMEM (control), but this difference was not found statistically significant. CONCLUSION: Capparis spinosa can be a suitable, alternative storage medium for avulsed teeth.

Evaluation of residual antimicrobial effects and surface changes of gutta-percha disinfected with different solutions.

AIM: To determine the possible residual antibacterial effects and possible surface changes caused by 5.25% NaOCl, 2.5% NaOCl, 2% CHX and 0.05% Octenisept on in vitro gutta-percha points after different disinfection protocols. MATERIALS AND METHODS: A total of 121 standard # 40, 0.2% gutta-percha cones were cut 10 mm from the tip, sterilized with ethylene oxide. The samples were divided into five groups, and each group was divided into three subgroups according to immersion periods of gutta-percha cones into solutions. One gutta-percha cone from each group was selected for SEM evaluation. RESULTS: All of the tested solutions were effective on the selected microorganisms when compared with the control solution. No surface alterations were detected on the gutta-percha cones. CONCLUSION: In the limits of this study, immersion of gutta-percha into 2% CHX for one minute was found the most effective method to eliminate the selected microorganisms. CLINICAL SIGNIFICANCE: Although gutta-percha points are aseptic in their package, once opened and used, gutta-percha cones may be contaminated. In order to eliminate bacteria and not to cause surface changes on gutta-percha cones, disinfection solution must be selected carefully.