Journal of Dental Medicine

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Background and Aim: An important requirement for a dentin bonding agent is biological compatibility. Since dentin bonding agents are placed in cavity preparations with subgingival extensions, with direct contact to gingival and mucosal tissues, tissue response to these materials must be investigated. The aim of this study was to examine the cytotoxicity of AdheSE, a self etching adhesive, on human gingival fibroblasts.
Materials and Methods: In this experimental in vitro study, primary human gingival fibroblasts were exposed to different dilutions of primer & bond of AdheSE (Vivadent, Liechtenstein). The toxicity of the primer was tested in 30 seconds, 300 seconds and 24 hours. The cytotoxicity of the bond was analyzed in uncured mode after 20 seconds, 5 minutes and 24 hours. In cured mode, tested materials were analyzed after 24 and 48 hours. Cytotoxic effects were evaluated using MTT, cell counting and DNA condensation assays. Data were analyzed by two way repeated measure ANOVA with p<0.05 as the level of significance.
Results: MTT Assay revealed that uncured AdheSE Bond was toxic only in 10-1 dilution and the difference with control group was significant (P<0.05). By increasing the time to 300sec. and 24h, dilutions of 10-2 and 10-4 were the most cytotoxic respectively. Cytotoxicity of uncured primer after 30 sec. and 300 sec. began from 10-2 and after 24h began from 10-2 and reached to 10-1. AdheSE in cured mode showed significant difference with control group in 1:2 (P<0.001),1:4 & 1:6 (P<0.01) dilutions. In cell counting assay only the 1:2 dilution was significantly more toxic than control group. Apoptosis (a morphological and biochemical distinct form of cell death that regulates cell turnover) comprised in less than 5% of total death in both cured and uncured adhesives.
Conclusions: Based on the results of this study, by increasing the exposure time, smaller amounts of bonding could be cytotoxic. Cytotoxicity was related to material, dilution, time of exposure and curing. It would be necessary to identify the toxic ingredients of this adhesive and replace them by more biocompatible components.

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Background and Aim: Root filling materials are usually in close contact with living tissues. So their biological properties like mutagenicity and cytotoxicity are important. These properties help us determine the potential damage to periapical tissues, or potential DNA mutations, and malignant transformation of the cells. The aim of this study was to evaluate the mutagenicity and cytotoxicity of four root canal sealers: AH Plus (Dentsply, DeTrey), Ketac-Endo Aplicap (3M ESPE), Sankin Apatite III (Sankin K.K), and Tubli-Seal EWT (Kerr).

Materials and Methods: In this experimental in vitro study fresh and set specimens from AH Plus, Ketac-Endo Aplicap, Sankin Apatite III, and Tubli-Seal EWT were immersed in culture medium for 1, 2 and 7 days. Cytotoxicity was assessed using tetrazolium bromide reduction assay (MTT) after 1, 2 and 7 days exposure of diluted extracts to L929 cells. Extracts of sealers in phosphate buffer saline (PBS) were used to examine the mutagenic effects by sos-umu test according to standard procedures. Data were analyzed using one way ANOVA, Kruskall Wallis, Mann Whitney and Post hoc tests with P<0.05 as the level of significance.

Results: Extracts of all freshly mixed sealers were cytotoxic. Ketac-Endo Aplicap and Sankin Apatite III showed the lowest toxicity respectively and Tubli-Seal EWT the highest. In contrast to other sealers, the cytotoxicity of Tubli-Seal showed no decrease with time. -galactosidase did not increase significantly thus none of the sealers showed mutagenic effects.

Conclusion: Based on the results of this study, Tubli-Seal EWT showed the highest cytotoxicity with time. Other sealers showed decreasing cytotoxicity with time. No mutagenicity effects was observed in none of  tested materials.

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Background and Aim: Several materials have been introduced for retrograde fillings, pulp capping and sealing root perforations, but their biological effect on vital tissues and cells is not clear. The purpose of this study was to evaluate the reaction of human periodontal ligament fibroblasts to four root canal filling materials: Pro Root MTA, Root MTA, Portland cement and amalgam.

Materials and Methods: In this experimental study, impacted or semi impacted third molar teeth were extracted in aseptic conditions and tissues around the roots were used to obtain fibroblast cell line. After proliferation, cells were cultured in chamber slides and extracts of materials were added to wells. Fibronectin, type I collagen and TGF-  expression were measured by immunocytochemistry method. Data were analyzed by SPSS 11.0 using one way ANOVA and Tukey test. P<0.05 was considered as the limit of significance.

Results: Collagen I expression was higher in Pro Root MTA group after 24 hours (p<0.05) and in Portland cement group and positive controls after 48  hours. Portland cement group showed the highest expression of collagen after 1 week. There was no significant difference in fibronectin expression after 24 hours. After 1 week the highest expression of fibronectin was seen in Portland cement, Root MTA and Pro Root MTA groups. TGF-  expression was higher in amalgam, Root MTA and Pro Root MTA specimens after 24 hours and was the highest in Pro Root MTA group after 48 hours.

Conclusion: Based on the results of this study, Portland cement and Root MTA are comparable with Pro Root MTA and better than amalgam regarding their effects on human periodontal ligament fibroblasts.