Comparative Evaluation of Cytotoxicity and Genotoxicity of Two Bioceramic Sealers on Fibroblast Cell Line: An in vitro Study.

AIM: The purpose of this study was to evaluate and compare the cytotoxicity and genotoxicity of two bioceramic root canal sealers: EndoSequence BC and iRoot SP with zinc oxide eugenol sealers on fibroblast cell line. MATERIALS AND METHODS: The sealers tested were zinc oxide eugenol, EndoSequence BC, and iRoot SP. Each material was mixed according to the manufacturer's instructions and mounted into sterile polyethylene color-coded rings, for cytotoxicity and genotoxicity evaluation. After 48 hours, the set materials were transferred to previously marked wells and cytotoxicity evaluation to L929 murine fibroblast cells was done by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The percentages of viable cells were then calculated and values were statistically analyzed by Kruskal-Wallis test. The evaluation of genotoxicity of the materials to L929 murine fibroblast cells was carried out by Comet assay. To quantify deoxyribonucleic acid (DNA) damage, the following comet parameters were evaluated in the assay using Comet scoring software: tail length, tail moment, and Olive moment. The values were statistically analyzed using Kruskal-Wallis test with a significance value set to p < 0.05. RESULTS: The results of the study showed that both cytotoxicity and genotoxicity evaluation by MTT assay and Comet assay can be done on L929 murine fibroblast cell line. Among the three tested materials, zinc oxide eugenol showed maximum cytotoxicity to the cells (30.64% viable cells), followed by EndoSequence BC (71.33% viable cells) and iRoot SP (75.11% viable cells). The evaluation of DNA damage by genotoxicity assessment showed iRoot SP to be least genotoxic followed closely by EndoSequence BC. Zinc oxide eugenol was genotoxic and induced more DNA damage on the fibroblast cell line studied. The statistical analyses for both the assays were nonsignificant. CONCLUSION: All the three tested sealers showed varying degrees of cytotoxicity and genotoxicity while using fibro-blast cell line. Zinc oxide eugenol was most toxic in both the assays and iRoot SP showed least toxicity, followed closely by EndoSequence BC.

Evaluation of Hybrid Layer and Bonding Interface after Water Storage with and without the Usage of 2% Chlorhexidine: A Scanning Electron Microscope Study.

AIM: Restorative dentists employ different bonding systems between the resin and the dentin and other dentinal tissues to achieve the goal of micromechanical retention. Studies have shown that the bond between composite and dentin degrades over time because of the action of matrix metalloproteinases (MMPs) on collagen fibrils left unprotected by acid etching. The MMPs may be partially responsible for hybrid layer degradation. Since chlorhexidine (CHX) inhibits MMPs, we hypothesized that CHX would decelerate the loss of resin-dentin bonds. Hence, this in vitro study is intended to evaluate the effects of 2% CHX on hybrid layer and bonding interface. MATERIALS AND METHODS: Totally, 40 freshly extracted molars were randomly divided into four experimental groups. In all 40 specimens, class II cavities were prepared to a depth of 1 mm below the dentinoenamel junction with no axial wall, but the elimination of the proximal enamel ridge. The teeth were then randomly divided into four experimental groups, i.e., All Bond 2 without 2% CHX (group I), All Bond 2 with 2% CHX (group II), One Coat 7.0 without 2% CHX (group III), and One Coat 7.0 with 2% CHX (group IV). All the specimens were derooted and sectioned mesiodistally into two halves and placed under water at 37°C for 3 months and observed under scanning electron microscope for the hybrid layer and resin tag formation. RESULTS: Groups I and II showed statistically significant difference when the presence/absence of resin tags was compared. When groups III and IV were compared for the presence/absence of hybrid layer and resin tags, the results were statistically significant. CONCLUSION: Between all the four experimental groups, irrespective of the bonding systems used, we concluded that groups with 2% CHX usage showed promising results with presence/ absence of hybrid layer and resin tags formation. CLINICAL SIGNIFICANCE: Studies suggest that the bond between composite and dentin degrades over time because of the action of MMPs on collagen fibrils left unprotected by acid etching. Measures should be taken to prevent this from happening and thus allow bond between composite and dentin last longer.

Comparative Evaluation of Tensile Strength in Die Stone Incorporated with Sodium and Calcium Hypochlorite as Disinfectants: An in vitro Study.

AIM: The aim of this study was to evaluate the tensile strength of die stone incorporated with sodium and calcium hypochlorite as disinfectants. MATERIALS AND METHODS: Two commercially available type IV die stone (Kalrock: Kalabhai Karson Pvt., Ltd and Pearlstone: Asian Chemicals) and two commercially available disinfectant solutions (sodium hypochlorite and calcium hypochlorite: Beachem Laboratory Chemical Private Limited, Chennai and Leo Chem Private Limited, Bengaluru) were used in this study, and the tensile strength was measured using Lloyd's Universal Testing Machine. RESULTS: The results show that incorporating the disinfecting solutions decreases the tensile strength of both products. The effect of decreasing tensile strength on type IV gypsum product is seen more in calcium hypochlorite when compared with sodium hypochlorite disinfecting solution, and the tensile strength of Kalrock specimens is higher than Pearlstone specimens after disinfecting with sodium hypochlorite and calcium hypochlorite solution. The statistical results also show significant results in all the groups when compared with the control group. CONCLUSION: The incorporation of sodium and calcium hypochlorite disinfecting solutions is not an encouraging method for both die materials as it reduces the tensile strength of type IV gypsum product. Tensile strength of Kalstone® die material is superior than Pearlstone® die material after mixing with sodium hypochlorite and calcium hypochlorite. CLINICAL SIGNIFICANCE: According to the recommendations of Americans with Disability Act (ADA) and the Centers for Disease Control and Prevention, disinfecting the whole cast without or minimal changes in physical and mechanical properties was the motto of the study. The tensile strength in type IV gypsum product plays a most important role in retrieval of cast from impression, especially in narrow tooth preparation. This study reveals that incorporating method of disinfecting solutions is not recommended as it reduces the tensile strength.

Clinical study to know the efficacy of Amlexanox 5% with other topical Antiseptic, Analgesic and Anesthetic agents in treating minor RAS.

BACKGROUND: To evaluate the efficacy of topical antiinflammatory agent (amlexanox 5%), along with topical antiseptic, analgesic, and anesthetic agent (benzalkonium chloride 0.01%, choline salicylate 8.7% and lidocaine hydrochloride 2%), in promoting ulcer healing, decreasing ulcer size, erythema, pain and recurrence in minor RAS. MATERIALS & METHODS: A randomized control trial was conducted on 100 patients of RAS who fulfilled the inclusion criteria. The number, size, erythema and pain with the ulcer were recorded. Visual analogue scale (VAS) and erythema scale were used to record pain and erythema. 50 patients comprising the study group received anti inflammatory paste (amlexanox 5%) applied four times daily and the control group of 50 patients received topical antiseptic, analgesic, and anesthetic agent (benzalkonium chloride 0.01%, choline salicylate 8.7% and lidocaine hydrochloride 2%) paste, patients were evaluated after 3rd, 6th, 9th and on 30th, 60th day for recurrence. RESULTS: The study group had reduction in ulcer number, size; erythema, pain and frequency of ulcers during follow up. The healing period and recurrence of ulceration reduced in both the groups but the study group had significant reduction in 30th and 60th day follow up for recurrence of ulcers. CONCLUSION: Amlexanox 5% can reduce the frequency, duration and symptoms associated with the aphthous ulcers with no sideeffects attributed to the drug. How to cite the article: Darshan DD, Kumar CN, Kumar AD, Manikantan NS, Balakrishnan D, Uthkal MP. Clinical study to know the efficacy of Amlexanox 5% with other topical Antiseptic, Analgesic and Anesthetic agents in treating minor RAS. J Int Oral Health 2014;6(1);5-11.