Cytotoxicity assessment of different doses of ozonated water on dental pulp cells.

BACKGROUND: The purpose of this study was to assess the cytotoxicity of various concentrations of ozonated water (OW) on human primary dental pulp cells. METHODS: Human primary dental pulp cells were isolated from exfoliated primary canine teeth of an 11-year-old patient with good systemic and oral health. Afterwards, cells were divided into 6 experimental groups; four groups of OW in concentrations of 2 mg/L, 4 mg/L, 8 mg/L, and 16 mg/L, untreated control group, and cell culture without cells. Cytotoxicity was evaluated after exposure for 5-min exposure using Mosmann's Tetrazolium Toxicity (MTT) assay at 0 h and 48 h time points. Data were analyzed using a repeated measures analysis of variance and Post-hoc tests were performed using Bonferroni correction for multiple comparisons. RESULTS: All experimental groups showed proliferation at 0 h time point. However, all groups also experienced a decrease in overtime at 48 h time point (p < 0.05). At both time points 2 mg/L OW showed the highest cell viability as well as proliferation. At 0 h time point, the increase in cell viability for all experimental groups was found statistically significant when compared to positive control group (p < 0.05). At 48 h time point, although 8 mg/L and 16 mg/L OW showed statistically significant reduction in compare to 0 h time point, 2 mg/L and 4 mg/L OW groups didn't experience any statistically significant difference (p < 0.05). CONCLUSION: Considering our findings, due to ozonated water's induced a higher proliferation rate of dental pulp cells, indicating their biocompatibility and a possible adjuvant on irrigating agent in regenerative endodontic procedures.

Evaluation of low-level diode laser irradiation and various irrigant solutions on the biological response of stem cells from exfoliated deciduous teeth.

This study aimed to evaluate cytotoxic effects and the apoptosis of Gallium-Aluminum-Arsenide (GaAlAs) diode laser irradiation, sodium hypochlorite (NaOCl), ozonated water and ethylene diamine tetraacetic acid (EDTA) on stem cells from human exfoliated deciduous teeth (SHEDs). Cells were exposed to EDTA (5%, 8.5%, 17%), NaOCl (1%, 2.5%, 5%) ozonated water (5, 10, 20 µg/ml) and GaAlAs diode laser irradiation (energy densities of 0.5, 1, 1.5 j/cm2). Culture medium included D-MEM, supplemented with 15% foetal bovine serum, 1% l-glutamine, 1% penicillin-streptomycin, 1% gentamycin, amphotericin-B and served as control group. The prepared irrigants were added to the relevant wells and incubated with the cells at 37 °C for 5, 10 and 15 min. The cells in the laser group were also incubated at 37 °C for 5, 10 and 15 min after the laser application. Cell viability and proliferation were analysed with the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. The percentage of cell viability showed a significant reduction in all concentrations of the EDTA and NaOCl groups when compared to the control group, diode laser irradiation and ozonated water groups at 5th, 10th and 15th minutes respectively but high cytotoxic effects of all EDTA and NaOCl groups with decreased over 50% of cell viability were observed at the 15th minute. Also EDTA group with 17% concentration (17%E) presented the lowest survival rate on SHEDs with mean of 21.67% ±â€¯6.101 at this time interval. The lowest toxic effects were observed at the 5th minutes compared to other time periods at experimental groups. For detection of apoptotic cells, the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) method was performed. According to the MTT results, doses showed the highest toxicity (cell survival decreased over 50%) in each group were selected for TUNEL assay (17% EDTA; 1% NaOCl; 10 µg/ml Ozonated water; 1.5 j/cm2 diode laser irradiation). The significantly lowest percentages of TUNEL-positive cells were detected in ozonated water (10.67% ±â€¯2.93) and diode laser irradiation (13.24% ±â€¯7.61) compared to EDTA (39.89% ±â€¯11.54) and NaOCl (31.15% ±â€¯10.64) respectively. Also the difference between percentage of TUNEL-positive cells in EDTA and NaOCl groups was not significant. Synergistic combination of ozonated water and diode laser irradiation may be used in the disinfection step of necrotic root canals.

Anti-erosive effects of fluoride and phytosphingosine: an in vitro study.

A selection of commercially available products containing stannous fluoride (SnF2 )/sodium fluoride (NaF), SnF2 /amorphous calcium phosphate (ACP), SnF2 /NaF/ACP, tin (Sn)/fluorine (F)/chitosan were compared with phytosphingosine (PHS) with respect to their anti-erosive properties in vitro. One-hundred and twenty bovine enamel specimens were immersed in the respective product slurries for 2 min, twice daily. The formulations were diluted with either remineralization solution or artificial saliva. After each treatment, an erosive challenge was performed for 10 min, twice daily, using citric acid, pH 3.4. The specimens were stored in remineralization solution or artificial saliva until the next treatment-erosion challenge. After 10 d, tissue loss was determined using profilometry. Enamel softening was determined through surface microhardness measurements. Tissue-loss values (measured in µm and expressed as mean ± SD) for PHS, SnF2 /NaF, SnF2 /ACP, SnF2 /ACP/NaF, and Sn/F/chitosan treatment groups and for the negative-control group, were, respectively, 35.6 ± 2.8, 15.8 ± 1.8, 22.1 ± 2.0, 22.9 ± 1.8, 16.2 ± 1.2, and 51.2 ± 4.4 in the presence of remineralization solution and 31.7 ± 3.3, 15.6 ± 2.9, 16.5 ± 2.7, 16.8 ± 2.1, 13.1 ± 3.0, and 50.7 ± 2.8 in the presence of artificial saliva. There were no significant differences in surface microhardness measurements between the treatment groups. In conclusion, PHS resulted in a significant reduction of tissue loss compared with the negative control, but in comparison, the toothpastes containing Sn(2+) and F(-) ions were significantly more effective compared with PHS.

Effect of Er,Cr:YSGG laser irradiation with radial firing tips on Candida albicans in experimentally infected root canals.

AIM: To compare the disinfection effect of Er,Cr:YSGG laser using radial firing tips with NaOCI in root canals infected with C. albicans and to evaluate the irradiation effect on the dentinal surfaces. MATERIAL AND METHODS: In total seventy-six mandibular premolar teeth were used. In order to standardize the incubation and sterilization procedure, eight teeth were used. Sixty-eight of the root canals were incubated with C. albicans suspension for 72 hours. The specimens were divided into 5 experimental groups. Two groups were constituted as Group 1 was irradiated with 1.5 W laser (n = 8) and group 2, which was irradiated with 2 W laser (n = 8). Two more groups were formed as Group 3 (2 W laser (n = 25) and Group 4 NaOCI (5%) (n = 25). Group 5 (n = 2) did not receive any treatment. Mann-Whitney U and Kruskal-Wallis H tests were used to compare the different laser output powers. Wilcoxon Signed Ranks Test was used in order to compare the Candida cfu/ml levels according to treatment protocols (P < 0.05). RESULTS: Both 1.5 W and 2 W laser resulted in a major reduction of C. albicans without a significant difference. The comparison of the dentin surfaces irradiated with Er,Cr:YSGG laser at two power settings resulted in similar morphological changes. However, NaOCI was found to be more effective in reduction of C. albicans than 2 W laser application. CONCLUSION: According to the results of the present study, the Er,Cr:YSGG laser with radial firing tips presented less antifungal effects on C. albicans in root canals of infected teeth than NaOCl solution.

Cytotoxic effects of halogen- and light-emitting diode-cured compomers on human pulp fibroblasts.

OBJECTIVE: The aim of this study was to determine the cytotoxic effects of three different compomers (Dyract AP, Compoglass, and Hytac) cured using a halogen light-curing unit (LCU) and a light-emitting diode (LED) LCU on human pulp fibroblasts. METHODS: Specimens of three compomers were added to human pulp fibroblast cultures. Cytotoxicity was evaluated over 96 h using the agar overlay method. RESULTS: All three compomers tested were found to be moderately cytotoxic to human pulp fibroblasts, regardless of whether they were cured using halogen or LED LCUs. The decolorization zone of Hytac was significantly larger than those of the other compomers tested (P < 0.05). Dyract AP and Compoglass specimens showed greater decolorization when cured with LED than with halogen LCUs (P < 0.05). CONCLUSION: Compomers are potentially toxic to human pulp fibroblasts, and the type of curing unit may affect compomer toxicity.

Hemisection of a fused tooth.

Fusion is a developmental anomaly which occurs due to a union of 1 or more adjacent teeth during morphodifferentiation of the dental germs. The present case report presents the hemisection of a maxillary central incisor fused with a supernumerary tooth. A 10-year-old boy was referred to clinic with the chief complaint of the presence of a large anterior tooth. Intraoral and radiographic investigations indicated fusion between the left central incisor and a supernumerary tooth. The fused tooth was separated with a diamond bur, and the supernumerary tooth was extracted. The left central incisor was restored with composite resin and the diastema between the maxillary central incisors was closed with orthodontic treatment. The left central incisor was still healthy after a follow-up examination period of 24 months. An ideal overjet and overbite relation was achieved at the end of the orthodontic treatment. Hemisection can be considered as an appropriate treatment alternative for a permanent tooth fused with a supernumerary tooth.

Regional odontodysplasia: report of a case.

Regional odontodysplasia is a rare developmental anomaly involving both mesodermal and ectodermal dental components in groups of contigous teeth. RO affects the primary and permanent dentition in the maxilla and mandible or both jaws. Generally, it is localized in only one arch. The maxillary arch is affected more often than the mandibular arch. The affected teeth tend to be in a consecutive series that does not cross the midline, although some cases do not follow this pattern, as in the present case, have been documented. Radiogaphically wide pulp chambers and thin poorly defined hard tissue outlines described as a "ghost teeth" appearance, are typical features. A case of regional odontodysplasia in a 5 year old male patient is presented. The clinical and radiogaphical findings of this developmental anomaly and treatment are described.