Abstract
Aims: To investigate the effect of the thickness of relining material, curing method (water bath or mi-crowave), and the surface treatment by methyl methacrylate on transverse and tensile strength of re-lined acrylic resin denture base. Materials and methods: A pilot study was done by preparing 65 sam-ples to evaluate the effect of the thickness of relining material in relation to denture base on the trans-verse strength of acrylic resin denture base, and to study the effect of surface treatment by methyl methacrylate on the transverse strength of acrylic resin denture base. The main study was done by pre-paring 320 samples and divided into two parts to study the mechanical properties of samples represent-ing a denture base cured by water bath and other group cured by microwave curing technique, and then the effect of relining by the two curing methods and the effect of surface treatment were evaluated. Analysis of variance (ANOVA) and Duncan's multiple range tests were used for statistical analysis. Results: of this study showed that the different thickness of relining material in relation to denture base had no significant difference on the transverse strength of the relined denture base. The transverse strength and tensile bonding strength of the relined samples were significantly improved (P=0.05) by monomer surface treatment for 180 seconds. Conclusions: Transverse and tensile strength of the acryl-ic resin denture base were affected by relining. Microwave curing method gave better mechanical properties of the relined acrylic resin denture base.