Evaluating the Effect of Lemongrass Essential Oil Addition on Some Properties of Heat Cure Acrylic Soft-Lining Material

Abstract

Background: Denture liners’ viscoelasticity absorbs shocks and relieves tissue pressure. Soft liners must be replaced every 6–12 months because oral conditions destroy elastomers. By adding chemicals to soft liners, researchers have created a new class of flexible, oral-friendly materials. This lowers denture and mucosa pressure. Objectives: The aim of the study is to discover if the best two concentrations of lemongrass essential oil (LGEO) added to heat-cured soft denture liner improves the material’s hardness, the strength of the peel bond, and surface roughness. Materials and Methods: In a pilot study, 2.5 vol.% and 5 vol.% LGEO improved the heat-cured soft-liner material’s Shore A hardness and surface roughness. The main study categorized 90 specimens into three groups (Shore A hardness, peel bond strength, and surface roughness). Each of the groups has three subgroups (control, 2.5 vol.% of LGEO additive, and 5 vol.% of LGEO additive). One-way analysis of variance, Dunnett’s T3 post hoc, Tukey’s honestly significant difference, and Fisher’s exact test were used for data analysis, which was significant at P < 0.05. Results: After adding 2.5 vol.% and 5 vol.% of LGEO additives (experimental subgroups), Shore hardness, peel bond strength, and surface roughness of the two experimental subgroups decreased significantly from the control subgroup at P < 0.05, except for 2.5 vol.% of the LGEO additive subgroup, which did not differ significantly at P > 0.05. When failure mode was assessed, all subgroups varied substantially. The 2.5 vol.% of LGEO addition specimens showed adhesive and cohesive failure with some mixed type, whereas 5 vol.% showed predominantly cohesive failure. Conclusions: LGEO enhances the hardness and surface roughness of the soft-lining material, making it more resilient and smoother. This leads to a greater cushioning effect and reduced damage to the oral tissues while decreasing the liner’s peel bond strength to an acceptable level. 5 vol.% is the best percentage that improves liner properties.