The Effect of Surface Treatment on the Transverse and Tensile Bonding Strength of Relined Acrylic Resin Denture Base (Part I)

Abstract

Aims:To investigate the effect of the thickness of relining material, curing method (water bath or microwave), and the surface treatment by methyl methacrylate on transverse and tensile strength of relined acrylic resin denture base. Materials and methods: A pilot study was done by preparing 65 samples to evaluate the effect of the thickness of relining material in relation to denture base on the transverse 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 preparing 320 samples and divided into two parts to study the mechanical properties of samples representing 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 acrylic resin denture base were affected by relining. Microwave curing method gave better mechanical properties of the relined acrylic resin denture base. A BHatim NA, AL-Omari AW Al -Rafidain Dent J Vol. 13, No2, 2013 Surface treatment and bonding of relined denture base Al -Rafidain Dent J Vol. 13, No2, 2013

Bond strength of hard and soft relining materials to thermoplastic monomer free microcrystalline polymer ( In-vitro comparative study)

“…This makes the surface of denture base resin porous and a form of mechanical interlocking structure among the two materials would be established through this layer. (16) This in agree with other researches suggesting that successful bonding among reline material and denture base resin depends on the effective penetration of monomer emanating from the polymerizing reline material into the denture base resin. This may explain the finding of higher values of both shear and tensile bond strength of Hard relining material to heat cured acrylic resin denture base material, followed by karadent that exhibits less porosity and no residual monomer.…”