Main Article Content
Background: Poly (methyl methacrylate) (PMMA) is the most commonly used material in construction of denture base due to its advantages but important disadvantages are inherent in this resin such as poor strength, low abrasion resistance therefore an attempts to improve the mechanical properties of poly (methyl- methacrylate) have taken the researcher through many years.
Aim: This study aimed to evaluate the effect of autoclave processing technique and water bath processing technique on tensile strength of acrylic denture base material and investigate the effect of different curing cycle of microwave disinfection of acrylic denture base material.
Materials and Methods: The study is based on preparing 105 samples ( in final dimensions of 80 mm Length, 9 mm Width, and 3 mm Thickness) divided into three main groups according to type of curing processing are : Group I (Slow); while Group II (Fast) and Group III (Control group) (water bath) characterized of each group as follow:-
Group I:- acrylic resin samples processed by autoclave (Slow) (121 ەC / 210 kap, for 30 min.).
Group II:- acrylic resin samples processed by autoclave (Fast) (121 ەC/ 210 kap, for 15 min.).
Group III:- acrylic resin samples processed by water bath (74 ەC for 1 hour and half then increase the temperature to boiling point for 30 min.).
Then each group subdivided into 5 groups according to number of cycles of microwave sterilization that are applied (control (distal water)(A),
1 microwave cycle (B), 3 microwave cycles (C), 5 microwave cycles (D),
7 microwave cycles(E)).
Results: The results of the present study data showed that the effect of thedifferent processing technique is non significant different while the effect of the different microwave irradiation showed a significant differences among the groups.
Generally, it could be concluded there is no difference in the processing technique between the water bath and the autoclave and also we found there is effect on acrylic denture base materials if it disinfected by microwave more than one cycle.