In vitro comparison of thermal conductivity compressive strength and tensile strength of acrylic base of complete denture and reinforced acrylic with nano silver

Abstract

Polymethylmethacylate used in prosthodontics base, have desirable and undesirable features. For example it has low thermal conductivity which causes low thermal persuasion of mouth soft tissue. The aim of this study is in vitro comparison of thermal conductivity, compressive strength and tensile strength of acrylic base of complete denture and reinforced acrylic with nano silver. materials and methods : For this study,36 specimens were prepared which divided into three groups. For thermal conductivity evaluation , ( Cussons Thermal Conductivity Apparatus) device, For tensile strength evaluation , ( Zwic Z/100,Germany) device And for compressive strength evaluation (dartek) device were used. Each group specimens was divided into two subgroups :One group was used as control (unmodified PMMA) and the other one was used as test (PMMA was mixed with 5% by weight nano silver).The results were analyzed with variance analysis test and SPSS15 soft ware. Results : This study showed that the mean thermal conductivity and compressive strength of reinforced PMMA were found to be significantly higher than the unmodified PMMA (P<0.05). while that the tensile strength decreased significantly after incorporation of nano silver (P<0.05). Conclusions : Because of our results and desirable effect of nano particle size of silver in improvement of thermal conductivity and compressive strength of polymethylmethacrylat, use of this material in palatal area of maxillary acrylic resin denture was recommended and it is desirable.