Cytotoxic Effects of Three Denture Base Materials on Gingival Epithelial Cells and Fibroblasts: An in vitro Study

Abstract

ABSTRACT Objectives Modern polyamide ‘flexible’ denture base materials have increased in popularity for use in removable partial dentures. The introduction of these new products warrants investigation of their relative potential for toxicity. The purpose of this study was to investigate three contemporary denture base materials used in fabricating definitive prosthetic restorations Materials and methods Two ‘flexible’ materials (Valplast™ and Duraflex™) formed by thermoplastic injection molding technique, and one traditional heat processed, methyl methacrylate resin material (Lucitone 199) were evaluated. Cultured gingival epithelial cells and fibroblasts were treated with conditioned media prepared from denture material disks and then assayed for cell toxicity by [3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide] (MTT) cell viability assay. Cell membrane damage was determined by measuring the release of cytoplasmic lactate dehydrogenase. Further confirmation of toxicity induced by the conditioned media was determined by staining the cells with live/dead stain and observing under a UV microscope. Results Data were analyzed by means of a linear model ANOVA followed by Tukey's post hoc tests for comparison among groups. The significance level adopted was 5% (p < 0.05). The three denture materials differed in their toxicity to the cells as assessed by MTT assay. Valplast conditioned media in general, especially the media of unpolished disks, was found to be toxic to both gingival fibroblasts and epithelial cells while media obtained from polished Lucitone and Duraflex were found to be less toxic. After 7 days of incubation with Valplast unpolished conditioned media, only 1 to 2% of the cells remained viable, while the polished disk conditioned media caused significantly less (p < 0.05) toxicity, approximately 76 and 92% of fibroblasts and epithelial cells respectively, were viable. After 7 days of incubation with media obtained from the other denture materials, 35 to 92% of fibroblasts and epithelial cells were found to be viable. The data obtained from lactate dehydrogenase (LDH) assay and live/dead mammalian cell viability assay were in agreement with the MTT viability assay. Conclusion Conditioned media from unpolished Valplast denture material appeared to be significantly more toxic to gingival fibroblasts and epithelial cells when compared to the polished Lucitone disk conditioned media as well as the media obtained from Duraflex. How to cite this article Ahuja S, Babu J, Wicks R, Garcia- Godoy F, Tipton D. Cytotoxic Effects of Three Denture Base Materials on Gingival Epithelial Cells and Fibroblasts: An in vitro Study. Int J Experiment Dent Sci 2015;4(1):11-16.