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Objectives: To investigate the effect of different materials and repairing techniques on the flexural strength of heat-cured acrylic denture bases.
Materials and methods: Seventy-five specimens of Probase Hot with rectangular shape (63x10x3mm.) were processed according to manufacturer’s instruction. Only three specimens were intact, the remaining was further divided into two main groups (n=36) by repairing using small gap (2/10mm) and big gap (9/17mm). In each group, three brands of repairing materials Kooliner (GC America Inc), Tokuyama Rebase Fast II (Tokuyama Co., Ltd, Tokyo, Japan), and Unifast Trad Pink (GC America Inc) were used to fill in the gap (n=12). Prior to testing, all specimens were immersed in distilled water at 37ºC for 43±2h. The flexural strength of intact and repaired specimens was calculated using three-point bending test with Shimadzu Universal Testing Machine. Two-way ANOVA was used to analyze the data at α=0.05. Simple effect test was also used to identify a significant difference of pairs.
Results: There was an effect of materials and repairing techniques on the flexural strength of acrylic denture bases. Unifast Trad Pink showed the highest repair strength among all materials, while repair using larger gap displayed higher repair strength than that with smaller gap. However, there was no significant difference in term of repairing technique in the group repaired with Tokuyama Rebase Fast II. The flexural strength of all repaired specimens was lower than that of intact specimens.
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