Susceptibility of Enamel Treated with Bleaching Agents to Mineral Loss after Cariogenic Challenge

Objectives. Controversial reports exist whether bleaching agents cause a susceptibility to demineralization. The aim of this study was to compare the calcium loss of enamel treated with different bleaching agents and activation methods. Method and Materials. The specimens obtained from human premolars were treated in accordance with manufacturer protocols; 10% carbamide peroxide, 38% hydrogen peroxide light-activated, 38% hydrogen peroxide laser-activated, and no treatment (control). After cariogenic challenge calcium concentrations were determined by Inductively Coupled Plasma Mass Spectrometry. Results. No differences were found between the calcium loss of the laser-activated group and 10% carbamide peroxide group (>0.05). However, the differences between laser-activated and control groups were statistically significant (<0.05). The differences between 10% carbamide peroxide and the control group were not significant (>0.05). On the other hand, the light-activated group showed a significantly higher calcium loss compared with the other groups (<0.05). Conclusions. The results show that bleaching agents may cause calcium loss but it seems to be a negligible quantity for clinical aspects

Are antibacterial component additions in etchants and adhesives effective against Streptococcus Mutans?

WOS: 000428110500007The aim was to investigate the antibacterial activity of various acids and adhesives with and without antibacterial components against Streptococcus mutans. The antibacterial activities of 35% phosphoric acid (Ultra-Etch), 37% phosphoric acid with benzalkonium chloride (Etch-37), adhesive with chlorhexidine (Peak Universal Bond) and without any agent (PQ1) were investigated by agar-diffusion test. The inhibition-zones were measured after 48 h of incubation. For the tooth-cavity model test; cylindrical cavities were prepared on occlusal dentin surfaces of human molars and divided into four groups (n = 10 cavity/group). Group 1: Ultra-Etch + Peak Universal Bond, Group 2: Ultra-Etch + PQ1, Group 3: Etch-37 + PQ1 were applied. The fourth group without any agent application served as control. The teeth were immersed in 5.8 x 10(6) cfu/ml of S. mutans solution to infect the cavities for 72 h before the application of the groups. After 72 h, dentin chips were collected from the cavity walls with burs for bacterial counting. Statistical analysis was performed by ANOVA, Bonferroni and Dunnett C tests (p < 0.05). Ultra-Etch and Etch-37 performed similar antibacterial activities in agar-diffusion test. Both acids showed better antibacterial activity compared to adhesives (p < 0.05). The antibacterial activity of PQ1 and Peak Universal Bond was observed to be inactivated by light-polymerization. According to the tooth-cavity model; Group I, II, and III demonstrated reduction in bacterial number and there was no significant difference between them. Antibacterial component additions in etchant and adhesive did not show superior antibacterial activity against S. mutans in both in vitro tests

Effects of resveratrol on hydrogen peroxide-induced oxidative stress in embryonic neural stem cells

WOS: 000315936300001PubMed ID: 25206691Resveratrol, a natural phenolic compound, has been shown to prevent cardiovascular diseases and cancer and exhibit neuroprotective effects. In this study, we examined the neuroprotective and antioxidant effects of resveratrol against hydrogen peroxide in embryonic neural stem cells. Hydrogen peroxide treatment alone increased catalase and glutathione peroxidase activities but did not change superoxide dismutase levels compared with hydrogen peroxide + resveratrol treatment. Nitric oxide synthase activity and concomitant nitric oxide levels increased in response to hydrogen peroxide treatment. Conversely, resveratrol treatment decreased nitric oxide synthase activity and nitric oxide levels. Resveratrol also attenuated hydrogen peroxide-induced nuclear or mitochondrial DNA damage. We propose that resveratrol may be a promising agent for protecting embryonic neural stem cells because of its potential to decrease oxidative stress by inducing higher activity of antioxidant enzymes, decreasing nitric oxide production and nitric oxide synthase activity, and alleviating both nuclear and mitochondrial DNA damage.Turkish Scientific and Technological Council (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK); Research Fund of Ege UniversityEge University [05/ECZ/020]Guliz Armagan acknowledges a scholarship for postgraduate students obtained from the Turkish Scientific and Technological Council (TUBITAK).; This study was funded by the Research Fund of Ege University, Project No. 05/ECZ/020

Are antibacterial component additions in etchants and adhesives effective against Streptococcus Mutans?

WOS: 000428110500007The aim was to investigate the antibacterial activity of various acids and adhesives with and without antibacterial components against Streptococcus mutans. The antibacterial activities of 35% phosphoric acid (Ultra-Etch), 37% phosphoric acid with benzalkonium chloride (Etch-37), adhesive with chlorhexidine (Peak Universal Bond) and without any agent (PQ1) were investigated by agar-diffusion test. The inhibition-zones were measured after 48 h of incubation. For the tooth-cavity model test; cylindrical cavities were prepared on occlusal dentin surfaces of human molars and divided into four groups (n = 10 cavity/group). Group 1: Ultra-Etch + Peak Universal Bond, Group 2: Ultra-Etch + PQ1, Group 3: Etch-37 + PQ1 were applied. The fourth group without any agent application served as control. The teeth were immersed in 5.8 x 10(6) cfu/ml of S. mutans solution to infect the cavities for 72 h before the application of the groups. After 72 h, dentin chips were collected from the cavity walls with burs for bacterial counting. Statistical analysis was performed by ANOVA, Bonferroni and Dunnett C tests (p < 0.05). Ultra-Etch and Etch-37 performed similar antibacterial activities in agar-diffusion test. Both acids showed better antibacterial activity compared to adhesives (p < 0.05). The antibacterial activity of PQ1 and Peak Universal Bond was observed to be inactivated by light-polymerization. According to the tooth-cavity model; Group I, II, and III demonstrated reduction in bacterial number and there was no significant difference between them. Antibacterial component additions in etchant and adhesive did not show superior antibacterial activity against S. mutans in both in vitro tests

Intrapulpal temperature changes during curing of different bulk-fill restorative materials

WOS: 000416395400007PubMed ID: 28626204The aim of this study was to evaluate the intrapulpal temperature changes during the curing of different bulk-fill restorative materials. Ten mandibular molar teeth were selected and occlusal surfaces were removed to obtain a standard 0.5 mm occlusal dentin thickness. Five bulk-fill restorative materials and a conventional resin composite (control) were applied. The intrapulpal temperature changes during the curing of these materials were determined by a device simulating pulpal blood microcirculation. The difference between the initial and maximum temperature values (At), was recorded. The data were statistically analyzed with one-way ANOVA and Tukey's HSD test (p<0.05). There were statistically significant differences between materials (p<0.001). The light-curing bulk fill restoratives exhibited the highest At values. Equia Forte showed the lowest At values among all the groups (p<0.05). Bulk-fill restorative materials causes significantly different temperature changes in the pulp chamber according to curing type. Therefore, clinicians should be considered when using these materials

Medium modification with bone morphogenetic protein 2 addition for odontogenic differentiation

WOS: 000378324000020PubMed ID: 26981753The aim of this study was to evaluate whether medium modification improves the odontogenic differentiation of human dental pulp stem cells (DPSC) in vitro and in vivo. DPSC isolated from human impacted third molar teeth were analysed for clusters of differentiation with flow cytometry. Odontogenic differentiation was stimulated by medium modification with the addition of bone morphogenetic protein 2 (BMP2). The expression of dentin sialophosphoprotein, dentin matrix protein 1, enamelysin/matrix metalloproteinase 20 and the phosphate-regulating gene with homologies to endopeptidases on the X chromosome of the cells were analysed with RT-PCR at 7, 14 and 21 days. Then, DPSC were transplanted on the back of immunocompromised mice via a hydroxyapatite tricalcium phosphate scaffold, and the structure of the formed tissue was investigated. The cells were identified as mesenchymal stem cells with a 98.3% CD73 and CD90 double-positive cell rate. The increase in mineralization capacity and expression of human enamel-dentin specific transcripts proportional to the culture period were determined after differentiation. Six weeks after transplantation, an osteo-dentin matrix was formed in the group in which odontogenic differentiation was stimulated, and the odontogenic characteristics of the matrix were confirmed by histological examination and RT-PCR analysis. Odontogenic differentiation of the isolated and characterized human DPSC was improved with medium modification by the addition of BMP2 in vitro and in vivo. The defined medium and applied technique have a potential use for forming reparative dentin in the future, but the effects of the method should be investigated in long-term studies.Ege University's Scientific Research FoundationEge University [2009-Dis-036]; Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)This study was supported by Ege University's Scientific Research Foundation (2009-Dis-036). We also acknowledge The Scientific and Technological Research Council of Turkey (TUBITAK) for its PhD scholarship support

The improvement of biocompatibility of adhesives: The effects of resveratrol on biocompatibility and dentin micro-tensile bond strengths of self-etch adhesives

WOS: 000474396700008PubMed ID: 30415440ObjectiveThe aim of this in vitro study is to evaluate the effects of resveratrol (RES) addition on the cytotoxicity and microtensile bond strength (mu TBS) of different adhesives.Materials and methodsFive self-etching adhesives (G-aenial Bond-GC, Optibond All in One-Kerr, Gluma Self Etch-Kulzer, Clearfil S-3 Bond-Kuraray, and Nova Compo-B Plus-Imicryl) were tested. They were applied to L-929 cell culture by the extract method. In the test groups, 0.5 mu M RES (Sigma-Aldrich) was added into the medium. Cell viability was assessed by MTT assay after 24h. Human extracted third molars were used for mu TBS test (n=7). The adhesives with or without 0.5 mu M RES addition were applied on dentin surfaces. A composite build-up was constructed. Then, the specimens were sectioned into multiple beams with the non-trimming version of the microtensile test and subjected to microtensile forces. Statistical analysis was performed using ANOVA and post hoc Tukey test (p?0.05).ResultsThe extracts of all adhesives decreased the cell viability. However, RES addition increased the cell viability in all groups (p?0.05). RES addition did not cause any decrease in mu TBS values of the adhesives compared to baseline. Optibond All in One showed the highest mu TBS after RES addition. It was followed by Clerafil S-3 Bond and Nova Compo-B Plus. No difference was determined between the Optibond All in One and Clearfil S-3 Bond. There was difference between Optibond All in One and Nova Compo-B Plus (p?0.05).ConclusionRES addition may improve the biocompatibility without causing negative influence on mu TBS of the adhesives.Clinical relevanceRES addition has clinical applicable potential to overcome the adverse biocompatibility of adhesives