Introduction: The purpose of this study is to examine the effect of different chelating solutions on microhardness and surface roughness of root canal dentin. Methodology: The crowns of sixty recently extracted maxillary central incisors were separated by diamond burs from the cemento-enamel junction. Roots are divided longitudinally into two pieces with diamond saw. The obtained samples were embedded in autopolymeric-acrylic and the dentin-surfaces of the teeth were grounded. Micro-hardness and surface-roughness measurements were carried out before the chelating processes. First group, the specimens were treated with gel-formed 17% Ethylenediaminetetraacetic acid [EDTA] (JE), second group, specimens were treated with 17% Liquid-formed EDTA (LE), third group, specimens were treated with 20% Citric acid (CA), and the last group specimens were treated with 7% Maleic acid (MA) for 120 seconds. After application of the chelating agents, micro-hardness and surface-roughness measurements of all samples were performed again. The difference between the initial and final measurements was calculated and statistically analyzed. One Way Analysis of Variance ANOVA was used for statistical-analysis and statistically significant difference was observed between the groups (p <0.05). Results: According to the test results, the microhardness of LE was statistically equal to that of JE and caused the least decrease in micro-hardness, SA decreased micro-hardness more than LE and JE, and MA decreased dentin micro-hardness more than all other solutions. And surface-roughness results are: MA increased surface-roughness more than other groups, SA and JE less roughened the dentin surface than MA, and there was no significant difference between the two solutions, LE caused less increase in dentin surface roughness compared to all solutions. Conclusions: Besides the use of EDTA and SA, the clinical use of MA can be considered, and it should also be noted that EDTA differs in terms of surface roughness between liquid and gel forms. How to cite this article: Topbaş C, Adıgüzel Ö, Çölgeçen Ö. Investigation of the effects of different chelating solutions on the microhardness and surface roughness of root canal dentin. Int Dent Res 2019;9(1):22-9. Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

The success of intraoral repair for fractured porcelain restorations has been questioned for many years. The longevity of the repaired restoration should be extended with effective methods that provide more sustainable clinical success. This study aimed to evaluate the effect of chairside plasma surface treatment on dental porcelain repair bond strength. Five hundred-fifteen rectangular specimens (12 × 14 × 1 mm) were fabricated from Cr-Co metal alloy (M) by lost wax technique, from zirconia (Z) and feldspathic (F) ceramic using the precision cutting device from CAD-CAM blocks. Specimens were pre-aged with 10,000 thermocycles to simulate intraoral conditions, and then divided into twenty-three subgroups: No treatment (M0, Z0, F0 groups/N = 45, n = 15), only plasma (MP, ZP, FP groups /N = 75, n = 25), only tribochemical silica coating via CoJet (MC, ZC groups/N = 30, n = 15), only hydrofluoric acid for feldspathic ceramic (FA group/n = 15), bonding agent (MB, ZB, FA groups /N = 75, n = 25), and their combinations (MCB, MCP, MPB, MCPB, ZCB, ZCP, ZPB, ZCPB, FPB, FAP, FAPB groups/N = 275, n = 25). Surface roughness (n = 10/per group), contact angle (n = 5/per group), shear bond strength (n = 10/per group), and failure modes (n = 10/per group) were evaluated. Statistical analyses were performed with a two-way analysis of variance at a significance level of α = 0.05. According to the results, plasma surface treatment increased the wettability of the materials without affecting surface roughness. When plasma was applied before the bonding agent, shear bond strength values were significantly improved (p < 0.001). The effectiveness of plasma and tribochemical silica coating was similar for zirconia (p = 0.960) and metal alloy substructures (p = 0.219). The MCPB, ZCPB, and FAPB groups had the highest bonding values within their main material groups (p < 0.001). Conclusively, chairside plasma surface treatment significantly enhances the shear bond strength of the repair material applied to the Cr-Co alloy, zirconia, and feldspathic ceramics without changing the surface roughness. It cannot replace HF acid or bonding agents, but it can serve as a substitute for tribochemical silica coating for dental porcelain repair procedures.

Activated charcoal (AC) toothpaste has gained popularity for its whitening properties. However, its abrasive effect on computer-aided design and computer-aided manufacturing (CAD/CAM) surfaces compared to conventional whitening toothpaste (WH) remains unclear. This study aimed to evaluate and compare the abrasive impact of AC and WH toothpastes on the surfaces of CAD/CAM materials. A total of ninety-six specimens were prepared from four different types of CAD/CAM materials: Feldspathic ceramic (Vita Mark II, Group VM), lithium disilicate-reinforced glass ceramic (IPS e.max CAD, Group EMC), polymer-infiltrated network hybrid ceramic (Vita Enamic, Group VE), and resin nanoceramic (Lava Ultimate, Group LU). Each specimen was prepared to a thickness of 2 mm and manually polished. Initial surface roughness was determined with profilometric analyses. The materials were then divided into subgroups (n = 8) based on three different brushing mediums: distilled water (DW), whitening toothpaste (WH), and activated charcoal toothpaste (AC). A toothbrushing simulator was used to simulate short-term (10,000 cycles-10k, about 1 year) and long-term (30,000 cycles-30k, about 3 years) brushing. After simulation, roughness measurements were repeated on the brushed surfaces, and changes in surface topography were evaluated using scanning electron microscopy images. Volumetric loss was calculated via digital volumetric analyses. Two-way repeated mixed analysis of variance was conducted to assess the effects of material type, brushing medium, and brushing time on the surface roughness, with significance set at α = 0.05. Group VM exhibited a significant increase in surface roughness after 10k cycles with AC, surpassing the clinical threshold (Ra > 0.2 μm). EMC showed no change at 10k but demonstrated a statistically significant increase at 30k cycles, also exceeding the threshold. Hybrid ceramics displayed increased roughness values, but all remained below the clinically relevant limit. Brushing with AC tended to produce greater roughness than WH in all materials. Digital volumetric analysis revealed that VM, VE, and LU groups experienced comparable volumetric loss, whereas EMC showed the least volumetric loss among all materials. AC-containing toothpaste increased surface roughness and volumetric loss in CAD/CAM materials, with more pronounced effects than whitening toothpaste. Feldspathic ceramics were particularly vulnerable to surface roughening, lithium disilicate showed higher resistance but was affected in the long term, while hybrid ceramics exhibited more evident volumetric loss. Therefore, the use of charcoal-based toothpaste is questionable, especially for patients with ceramic restorations.

Aim: This study aimed to investigate the effects of the repeated usage of a home-bleaching agent (16% carbamide peroxide) on the surface roughness of commonly used computer-aided design-computer-aided manufacture (CAD-CAM) restoration materials. Methodology: Five different CAD-CAM restoration materials were used in this study: feldspathic ceramic (Vita Mark II—Group VM II), leucite-reinforced glass ceramic (IPS Empress CAD—Group EMP), lithium disilicate-reinforced glass ceramic (IPS e.max CAD—Group EMAX), polymer infiltrated network hybrid ceramic (Vita Enamic—Group VE), and resin nanoceramic (Lava Ultimate—Group LU). A home-bleaching agent containing 16% carbamide peroxide was applied in three repeated periods (10 days, 20 days, and 30 days of exposure). A surface profilometer was used to determine the roughness average (Ra) values of the specimens. The data obtained were statistically analyzed using repeated measures of the analysis of variance (ANOVA) and Bonferroni post-hoc test at a 5% level of significance. Results: All materials exhibited a rougher surface after the first treatment period (10 days of exposure). The roughness of Group VM II continued to increase for up to 20 days. With the exception of Group LU, all groups exhibited a significantly rougher surface after 30 days of exposure compared to the baseline values (p < 0.05). The greatest variation in surface roughness was observed for the ceramic-based groups (VM II, EMP, and EMAX) rather than the hybrid groups (LU and VE). Conclusion: Patients with ceramic-based CAD-CAM restorations should be careful during home-bleaching treatment, especially when repeated applications are involved. Hybrid materials, particularly Lava Ultimate, seem more resistant to the effects of repeated bleaching cycles than ceramic-based materials. How to cite this article: Çölgeçen Ö, Köse M. Effects of repeated home bleaching on the surface roughness of CAD-CAM restoration materials. Int Dent Res 2022;12(3):143-8. https://doi.org/10.5577/intdentres.2022.vol12.no3.6 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Microbial colonization is a major factor contributing to peri-implantitis, and creating durable glassy surfaces with antimicrobial agents such as silver and copper may reduce microbial accumulation on dental abutments. This study aimed to develop antimicrobial thin-film glassy surfaces on Ti6Al4V alloy and to evaluate their surface and mechanical properties, antimicrobial effectiveness, and biocompatibility before and after thermal aging. A sol–gel-derived glassy matrix (G) was synthesized, and two antimicrobial coatings were prepared by incorporating ionic Ag (GAg) or a combination of Ag/Cu (GAgCu). Ti6Al4V specimens; these were either left uncoated or dip-coated with G, GAg, or GAgCu and cured at 450 °C. Half of the specimens underwent thermal aging between 5 °C and 55 °C for 3000 cycles. Surface roughness, contact angle, hardness, adhesion strength, scratch resistance, cytotoxicity (Agar diffusion and MTT assay on L929 fibroblasts), and microbial adhesion were evaluated using Streptococcus sanguinis, Porphyromonas gingivalis, and Candida albicans as representative oral microorganisms. Both coatings exhibited low surface roughness, hydrophilic surfaces, improved hardness, and significantly reduced microbial adhesion for all tested species. GAg showed superior mechanical properties, whereas GAgCu demonstrated a relatively stronger antimicrobial effect. Cytotoxicity tests indicated that all coatings were biocompatible at levels suitable for oral use. Overall, these coatings demonstrated strong adhesion, durability, and antimicrobial activity, suggesting their suitability for dental abutments made of Ti6Al4V.

This study primarily aimed to evaluate the degree of conversion (DC) of dual-cure resin cements, flowable composites, and bulk-fill composites used for cem