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

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.

Comparative analysis of cytotoxicity effects of two denture hard lining materials on human gingival fibroblasts: an in vitro study

“…In Wicks et al’s ( Wicks et al, 2015 ) study, the cytotoxic effects of three varieties of acrylic denture base materials were assessed on human gingival epithelial and fibroblast cells. Notably, some of the acrylic discs were left unpolished.…”

“…The fit of dentures naturally decreases over time due to changes in the tissues that support them. The denture’s adaptability to oral tissues can be improved by both hard and soft lining materials ( Wicks et al, 2015 ). Linings for dentures are polymers applied to their interior surfaces to improve their ability to adapt to oral tissues.…”

“…Chairside relining has gained popularity because it requires less time and effort than laboratory procedures. Removable or provisional denture bases can be directly relined with self-curing resins to achieve a reliable fit ( Hong et al, 2010 , Chaves et al, 2012 , Wicks et al, 2015 , Masetti et al, 2018 ). TDV and Rebase II have been commonly used in recent years to reduce the delivery time of removable dental prosthesis bases and improve their compatibility with removable dental prosthesis bases ( Jontell et al, 1995 , de A.L.…”

Effect of nano silica coating concentration on reducing acrylic resin denture cytotoxicity

“…17 In vitro cell toxicity was studied by seeding density of 2x10 4 cells / 100 μL onto 96 well plates. 18 and incubated for 24 hours. Subsequently, the acrylic resin was placed and incubated for 24 hours.…”

The effect of Zirconium Dioxide nanoparticles concentrations as filler on heat cured acrylic resin denture base toward viability of fibroblast cells (in vitro study)

“…20 Cultured cells were incubated for 24 hours, and each acrylic resin samples in the wells was incubated for 24 hours. 21,22 Culture media was thrown and all samples were taken out from the wells. 100 µL 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) solution were put in each well, then incubated for 4 hours on 37 °C.…”