Cytotoxicities and genotoxicities of cements based on calcium silicate and of dental formocresol

Cytotoxicity and genotoxicity of various types of endodontic sealers in Chinese hamster ovary (CHO-K1) cells

This study aimed to evaluate the cytotoxicity and genotoxicity of five endodontic sealers (AH Plus, MTA Fillapex, Endoseal MTA, Sealapex, and Zinc oxide eugenol) in Chinese hamster ovary cells. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay to check cell viability at 1, 3, and 7 days. Genotoxicity was assessed by cytokinesis-block micronucleus, single-cell gel electrophoresis, and γH2AX immunofluorescence assays. Cell viability of all endodontic sealers, except Endoseal MTA, on day 1 was less than 100%. Endoseal MTA showed the highest cell viability on day 7. AH Plus and Endoseal MTA showed less DNA damage than other sealers. After complete setting, AH Plus and Endoseal MTA showed low genotoxicity, which could reduce DNA damage in periapical cells, making them suitable as endodontic sealers.

An Evaluation on Deep Caries Removal Method and Management Performed by Undergraduate Dental Students: A Malaysia Experience

OBJECTIVES

 The aim of this study was to investigate the current knowledge and attitude of deep caries removal method among dental students in Malaysia.

MATERIALS AND METHODS

 A total of 303 students (n = 303) responded to the online questionnaire. The first part of questionnaire was to evaluate the demographic data of the respondents and focused on the technique and management approach used for deep caries lesion. The second part investigated the preferred treatment used for deep caries based on the designated clinical case, while the third part assessed the factors that affected the decision on deep caries management.

STATISTICAL ANALYSIS

 Independent t-test was used to compare difference between the two groups.

RESULTS

 Seventy four percent of the students have the knowledge of the different methods of caries removal, while 25.8% were only familiar with complete caries removal. The preferred method for deep caries removal in permanent teeth was partial caries removal (53%). For primary dentition, 45.6% of the students prefer to perform pulpotomy as compared with other techniques. There was no significant difference in caries removal method for permanent teeth between undergraduate year of study (p > 0.05), which was partial caries removal at 52.7 and 53.5%, respectively. For primary dentition, the preferred caries removal method was pulpotomy for year 4 (39.8%) and year 5 (52%) students. The popular material to restore deep caries was resin composite (42%) followed by glass ionomer cement (23.3%).

CONCLUSIONS

 This study showed that partial caries removal was the preferred method despite partial understanding on the identification of the clinical indicators of the technique.

Genotoxicity of root canal sealers: a literature review

OBJECTIVES

Root canal sealers are widely used worldwide in endodontics to prevent reinfection and growth of surviving microorganisms. Considering the strong correlation between genetic damage and carcinogenesis, evaluation of genotoxicity induced by endodontic sealers is recommended for elucidating the true health risks to patients and professionals. The purpose of this article was to provide a comprehensive review of studies involving genotoxicity analysis of endodontic sealers and the used methodologies.

MATERIALS AND METHODS

A literature search was made in PubMed using the following combination of words "genotoxicity," "mutagenicity," "endodontic sealers," and "root canal sealers." A total of 39 articles with genotoxicity studies were selected for the present study.

RESULTS

Sealers have been ranked in decreasing order of their genotoxicity as: ZOE sealers > GIC sealers > S sealers > ER sealers > MR sealers > Novel sealers > CH sealers > CS sealers.

CONCLUSIONS

All published data showed some evidence of genotoxicity for most of the commercial root canal sealers; however, contradictory results were found, mainly for AH Plus, the most studied sealer.

CLINICAL RELEVANCE

The information provided would direct the endodontists to use the less genotoxic materials in endodontic treatment in a way to reduce DNA damage promoting oral healthcare.

CYTOTOXIC EFFECTS OF DULOXETINE ON MKN45 AND NIH3T3 CELL LINES AND GENOTOXIC EFFECTS ON HUMAN PERIPHERAL BLOOD LYMPHOCYTES

ABSTRACT BACKGROUND: Gastric cancer is the second leading cause of cancer-related death globally. Unfortunately, the survival rate of the gastric cancer patients who underwent chemotherapy following surgery has been less than a half. Besides, chemotherapy has many side effects. Current evidence suggests that some antidepressants like duloxetine have growth-inhibiting effects against a number of cancer cell lines. OBJECTIVE: Thus, the aim of this study was to determine the cytotoxic and genotoxic effects of duloxetine on gastric cancer. METHODS: In this regard, the cytotoxicity and genotoxicity of duloxetine were investigated in MKN45 and NIH3T3 cell lines by MTT assay and on peripheral blood lymphocytes by MN assay. For this purpose, cells were cultured in 96 wells plate. Stock solutions of duloxetine and cisplatin were prepared. After cell incubation with different concentrations of duloxetine (1, 10, 25, 50, 100 and 200 μL), MTT solution was added. For micronucleus assay fresh blood was added to RPMI culture medium 1640 supplemented, and different concentrations of duloxetine (1, 10, 25, 50, 100 and 200 μL) were added. RESULTS: The cytotoxicity of duloxetine on MKN45 cancer cell line and NIH3T3 normal cell line were studied followed by MTT assay. duloxetine exhibited higher IC50 in the MKN45 cells in comparison with the NIH3T3 cells. In addition, genotoxic effect of duloxetine was evaluated by micronucleus assay. The results revealed that duloxetine induced more DNA damage at 100 and 200 μM and no significant difference at 200 μM with respect to cisplatin, but it had less genotoxic effects at 100 and 50 μM concentrations. CONCLUSION: Although, in this study, duloxetine had less genotoxicity than cisplatin in concentrations under 200 μM and showed cytotoxic effects as well, due to its IC50, it cannot be considered as a better choice for gastric cancer therapies with respect to cisplatin as a common anticancer drug.