Comparison of Salivary Bacterial Flora in Iranian Patients with Hiatal Hernia and Healthy Subjects

Objective: To evaluate salivary microbial flora of patients with hiatal hernia and compare it with that of healthy subjects. Material and Methods: In this cross-sectional study, 50 patients with hiatal hernia measuring >1 cm and 50 healthy subjects (as the controls) were selected using simple random technique. One mL of salivary sample was taken from each patient, transferred into 50-mL Falcon tubes and immediately carried to the microbiology Laboratory of Tabriz Faculty of Medicine. The salivary samples were cultured on specific Streptococcus viridans (S. mitis, S. mutans, S. salivarius and S. sanguis), Enterococcus spp. and Lactobacillus culture media. Then the samples were incubated at 37°C for 7 days, followed by evaluation of the bacterial colonies. Statistical significance was defined at p<0.05. Results: A total of 34% of subjects with hiatal hernia and 26% healthy subjects exhibited Lactobacillus gasseri in their salivary samples; 16% of subjects with hernia and 6% of healthy subjects exhibited Enterococci spp. in their salivary samples. In addition, 82% of subjects with hernia and 72% of healthy subjects exhibited S. mutans in their salivary samples; 74% and 4% of subjects with hernia and 76% and 4% of healthy subjects exhibited gram-positive and gram-negative bacilli in their salivary samples, respectively. Furthermore, 98% of subjects with hernia and 86% of healthy subjects exhibited gram-positive cocci in their salivary samples, however without significant difference between the groups (p>0.05). Conclusion: No significant differences in the counts of Lactobacillus spp., Enterococcus spp., Streptococcus viridans and gram-positive and gram-negative bacterial species between healthy controls and subjects with hiatal hernia.

Strong antimicrobial activity of Hypericum perforatum L. against oral isolates of Lactobacillus spp.

Lactobacillus spp. are one of the first microorganisms involved in the development of dental caries in the first years of life of the child. The purpose of this study was to investigate the antibacterial effect of alcoholic extract of hypericin against strains of Lactobacillus spp. and determine its related MIC (minimum inhibitory concentration); and cytotoxic effect against gingival fibroblasts. Antimicrobial activity and MIC were evaluated using micro broth dilution method based on CLSI (clinical and laboratory standards institute) protocols. Determination of cytotoxicity was done by using MTT assay protocol on gingival fibroblast cells at 24, 48 and 72 hours after adding different concentrations of alcoholic extract of hypericin. Hypericin extract had an antimicrobial effect on lactobacillus spp., and its MIC was determined to be 0.625µg/ml . The IC50 value after 24, 48 and 72 hours was obtained as 0.89µg/ml, 0.7µg/ml and 0.604µg/ml, respectively. Hypericin extract MIC for L.acidophilus spp. was 0.625µg/ml and given that, MIC was less than IC50. This concentration does not have toxic effects on gingival fibroblast cells. The results of this study indicate that hypericin extract was able to eliminate acid producing strains in the mouth and can be evaluated as a suitable and safe substitute for mouthwashes and oral disinfectants.

In vitro Cytotoxicity Comparison of MTA Fillapex, AH-26 and Apatite Root Canal Sealer at Different Setting Times.

INTRODUCTION: This study aimed to compare the cytotoxicity of MTA Fillapex, AH-26 and Apatite root canal sealers at different times after mixing. METHODS AND MATERIALS: In this in vitro study, MTA Fillapex, AH-26 and Apatite root canal sealer were spilled uniformly by 40 µm mesh in a 96-well plate. Then, human fetal foreskin fibroblast cell line (HFFF2) were added to each sealer cell culture medium. Cytotoxicity was measured using MTT assay after 24, 48 and 72 h and seven days. Multiple comparisons were done using analysis of variances (ANOVA) and Scheffe's post hoc test. RESULTS: All studied sealers exhibited severe cytotoxicity (more than 70%) except for Apatite sealer (95%) at 48 h after mixing. Cytotoxicity of MTA Fillapex and AH-26 were similar (P>0.05) at 24, 48 and 72 h and 7 days after mixing of sealers. Cytotoxicity of MTA Fillapex and Apatite root canal sealer, at 24 and 48 h, were significantly different (P=0.003 and P=0.000, respectively); MTA Fillapex was more cytotoxic. However in 72 h and 7 days after mixing, the difference was not significant (P>0.05). At 24 and 48 h after mixing, AH-26 was more cytotoxic (P=0.002 and P=0.000, respectively). Same as above at 72 h and 7 days after mixing, their cytotoxicity were similar (P>0.05). CONCLUSION: Overall cytotoxicity of all studied materials were severe. However, it was observed that the cytotoxicity of MTA Fillapex, AH-26 and Apatite root canal sealer decreased over time. Apatite root canal sealer exhibited the least cytotoxicity. Cytotoxicity of MTA Fillapex and AH-26 were similar at different time intervals.

Biocompatibility of Mineral Trioxide Aggregate with TiO2 Nanoparticles on Human Gingival Fibroblasts.

BACKGROUND: The New compositions of white mineral trioxide aggregate (WMTA) or use of various additives like nanoparticles might affect MTA's ideal characteristics This study was performed to evaluate the cytotoxicity of WMTA and WMTA with Titanium dioxide (TiO2) nanoparticles (1% weight ratio) at different storage times after mixing on human gingival fibroblasts (HGFs). MATERIAL AND METHODS: HGFs were obtained from the attached gingiva of human premolars. HGFs were cultured in Dulbecco's Modified Eagle medium, supplemented with 10% fetal calf serum, penicillin and streptomycin. The cells were exposed to WMTA (groups 1 and 2) and WMTA+TiO2 (groups 3 and 4). The fifth and sixth groups served as controls. Each group contained 15 wells. After 24h (groups 1, 3 and 5) and 48 h (groups 2, 4 and 6) of exposure, HGF viability was determined by Mosmann's tetrazolium toxicity (MTT) assay. Statistical analysis of the data was performed by using one-way analysis of variance and Tukey post hoc test, with significance of p < 0.05. RESULTS: With both materials, the viability of HGFs significantly decrased with increasing the incubation time from 24h to 48 h (P<0.05). There was no significant difference between the materials regarding HGF viability (P>0.05). CONCLUSIONS: Under the limitations of the present study, incorporation of TiO2 nanoparticles into MTA at 1 wt% had no negative effect on its biocompatibility. Key words:Cytotoxicity, fibroblast, MTA, MTT assay, nanoparticle, TiO2.

Survey of the Antibiofilm and Antimicrobial Effects of Zingiber officinale (in Vitro Study).

BACKGROUND: Candidiasis is one of the most prevalent and important opportunistic fungal infections of the oral cavity caused by Candida yeast species like Candida albicans, C. glabrata, and C. krusei. In addition, several bacteria can cause oral infections. The inhibition of microbial biofilm is the best way to prevent oral infections. OBJECTIVES: The aim of the present study is to evaluate the antifungal, antimicrobial, and anti-biofilm properties of ginger (Zingiber officinale) extract against Candida species and some bacterial pathogens and the extract's effects on biofilm formation. MATERIALS AND METHODS: Ginger ethanolic extract as a potential mouthwash was used to evaluate its effect against fungi and bacteria using the microdilution method, and biofilm was evaluated using the crystal violet staining method and dead/alive staining. MTT assay was used to evaluate the possible cytotoxicity effects of the extract. RESULTS: The minimum inhibitory concentrations (MICs) of ginger extract for evaluated strains were 40, 40, 20, 20, 20, 20, 10, and 5 mg/mL for Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus cereus, Acinetobacter baumannii, C. albicans, and C. krusei, respectively. Ginger extract successfully inhibited biofilm formation by A. baumannii, B. cereus, C. krusei, and C. albicans. MTT assay revealed no significant reduction in cell viability after 24 hours. The minimum inhibitory biofilm concentrations (MIBCs) of ginger extract for fungi strains (C. krusei and C. albicans) were greater than those of fluconazole and nystatin (P = 0.000). CONCLUSIONS: The findings of the present study indicate that ginger extract has good antifungal and antibiofilm formation by fungi against C. albicans and C. Krusei. Concentrations between 0.625 mg/mL and 5 mg/mL had the highest antibiofilm and antifungal effects. Perhaps, the use of herbal extracts such as ginger represents a new era for antimicrobial therapy after developing antibiotic resistance in microbes.

An in vitro comparison of coronal microleakage of three orifice barriers filling materials.

INTRODUCTION: A coronal barrier in root-filled teeth is one of the most effective methods for prevention of coronal microleakage. The aim of this study was to compare coronal microleakage of three materials [light-cured glass-ionomer (GI), mineral trioxide aggregate (MTA), and composite resin] as coronal barriers. MATERIALS AND METHODS: A total of 188 intact maxillary incisors were used. After instrumentation, all the canals were obturated with gutta-percha and lateral condensation technique using AH26 sealer. Then, the teeth were sectioned just apical to the cemento-enamel junction. The roots were randomly assigned to three experimental groups (n=56) and two negative and positive control groups (n=20). After placing the orifice barrier, the samples were immersed in 2% methylene blue solution for 2 weeks at 37°C. Then the teeth were longitudinally sectioned mesiodistally and dye penetration was measured under a stereomicroscope at ×10 magnification. Data were analyzed with one-way ANOVA and a post-hoc Tukey test. RESULTS: The positive control group leaked significantly more than all the experimental groups (P=0.001). MTA exhibited less leakage than composite and GI (P=0.002) but no significant differences were found between GI and composite groups. CONCLUSION: Immediate placement of a suitable intra-orifice barrier like MTA, before final restoration, may help minimize recontamination of the remaining apical gutta-percha.