Abstract
Aims: To estimate the effects of plant oil (coconut oil and/or rosemary oil) in two concentrations on the hardness and roughness of cold-cured acrylic resin. Materials and Methods: 50 samples each measuring 30 mm in diameter and 3 mm in thickness were made from cold-cured acrylic resin. Forty samples were made with the addition of rosemary and coconut oils at concentrations of 1.5% and 2.5%, respectively, while ten samples were made without any oils (the control). Each oil concentration is represented by those ten samples. A profilometer was used to measure the surface roughness (µm) and shore D hardness for each group. One-way analysis of variance (ANOVA) and the LSD test were both used to analyze the results. A level of P≤0.05 was regarded as significant. Results: Adding rosemary at concentrations of 1.5% and 2.5% would increase the value of Shore D hardness, causing an enormous variance from the control (P≤0.05). However, the addition of coconut oil considerably decreased the shore D hardness in comparison to the control group. Apart from the 2.5% coconut oil, which resulted in an extremely significant rise in surface roughness from the control and other experimental groups, the results revealed no noticeable difference in surface roughness between the control group and experimental groups. Conclusions: The hardness of cold-cured acrylic resin was increased when adding rosemary oil in concentrations of 1.5% and 2.5%, with 1.5% rosemary achieving the best findings. However, there was no effect on surface roughness when adding rosemary and coconut oil, excluding the concentration of 2.5% coconut oil, which had an adverse impact on the surface roughness of cold-cured acrylic resin.
