Investigation of dental elastomers as oral mucosa simulant materials

Abstract

Objective: To measure mechanical properties of dental soft liners in tensional stress to identify their suitability as human oral mucosa simulant materials.

Methods: Eleven different dental elastomers were subjected to tensile testing to obtain their tensile strength and elastic moduli (n = 15/group) according to the ISO-527 method. Fractured surfaces of one specimen per sample group were examined under the light microscope and scanning electron microscope (SEM). Energy-dispersive X-ray spectroscopy (EDS) was performed for the elemental analysis or chemical characterization of each sample group. The obtained data were quantitatively and qualitatively analysed. They were also statistically analysed using SPSS version 25.

Results: The tensile strength of dental elastomers ranged from 0.43 MPa (±0.09) to 7.41 MPa (±1.11) and had statistically significant differences between tested groups (p = 0.001). Vertex soft heat-cure soft liner, GC impression silicones and Silagum soft liners were found to have tensile strengths close to that of the oral mucosa reported by previous studies. SEM analysis revealed that the elastomers with higher filler contents showed rough fractured surface with plucking of particles after tensile fracture.

Conclusion: This is the first study assessing the suitability of dental elastomers as human oral mucosa simulant materials which can be used for in vitro, mathematical modeling and finite element analysis (FEA) to study masticatory force distribution in oral mucosa. Out of 11 studied, six (Vertex Soft, GC heavy and Light body, Molloplast B, Algin X Ultra and Exaclear) dental elastomers showed similar mechanical properties to the Theil embalmed gingival tissues. Vertex Soft, GC Light body, and Molloplast B may be used for the majority of oral mucosal model when considering tensile strength as the primary factor for mechanical stimulation.

Keywords: dental elastomer; mechanical properties; oral mucosa; silicone.