Effect of different denture cleanser solutions on some mechanical and physical properties of nylon and acrylic denture base materials

Abstract

Background: Thermoplastic non –metal clasp denture became recently the most attractive option for patients dueto its esthetic outcome and many other advantages. The chemical immersed denture cleanser is the most widelyused method by the patients to maintain clean and healthy denture , but the use of such cleanser may haveharmful effect on the denture base materials .This study aimed to evaluate some physical and mechanicalproperties of one of the thermoplastic denture base materials which is (nylon) compared with those belong toconventional heat cured acrylic and to observe the effect of two prepared denture cleansers ( 4% oxalic acid ,4%tartaric acid ) in addition to one commercial denture cleanser (lacalut dent) on the indentation hardness , flexuralstrength , flexibility , surface roughness and color stability of nylon and conventional heat cured acrylic.Materials and method: Two hundred and sixty specimens (130 nylon and 130 acrylic) were prepared ,60 specimens(30 nylon ,30 acrylic ) were used to test each of the properties mentioned above except an 80 specimens were used(40 nylon ,40 acrylic ) to test flexural strength and flexibility.Results: The result obtained in the present study showed high significant difference between nylon and conventionalheat cured acrylic in four properties which were: indentation hardness , flexural strength , flexibility and color stability,with no difference in the surface roughness .Furthermore oxalic acid and tartaric acid cleansers significantlydecrease the indentation hardness and flexural strength of conventional heat cured acrylic while lacalut dent didn’tsignificantly affect those properties of acrylic, also all the three cleansers didn’t affect the indentation hardness andflexural strength of nylon .oxalic acid and tartaric acid cleansers significantly decreased the flexibility of nylon whilelacalut dent didn’t significantly changed this property. All the three cleanser had no effect on the flexibility ofacrylic. All the three cleanser had no effect on the surface roughness or color stability of nylon and acrylic.Conclusions: It can be concluded that nylon had better flexibility and translucency than conventional heat curedacrylic while conventional heat cured acrylic had better indentation hardness and flexural strength than nylon.Regarding surface roughness the two polymers show no significant difference between them.There were an adverse effect of the prepared denture cleansers which contain isopropyl alcohol on indentationhardness and flexural strength of conventional heat cured acrylic , it decreased both those properties , so it isadvised not to use solution containing alcohol as acrylic denture cleanser also it is advised not to use it withnylon denture because it decreased its flexibility. Lacalut dent which is an oxygenating commercial denturecleanser, had no adverse effects on both polymers used in the study, so it can be used safely with them