Abstract
Aims: To evaluate the effect of two disinfecting solutions (povidone iodine 10%, ethanol alcohol 100%) on the surface roughness and surface hardness of nylon denture base material. Materials and Method: 40 sample of valplast material were constructed with dimensions of (65mm,10mm,2.5mm) length ,width and thickness respectively. (10) samples were used to measure the surface roughness before and after soaking in (ethanol material 100%) for 5 min., (10) samples were used to measure the surface hardness before and after soaking in (ethanol alcohol 100%) for 5 min., other 20 samples have been used in the same way as the 1st 20 but with iodine disinfectant. Results: Descriptive statistics for indentation hardness of valplast in ethanol and iodine indicate there is no significant difference for each one (P=0.3, P=0.7 respectively).T-test indicate there is no significant difference between them (P=0.3).Descriptive statistics for surface roughness in ethanol indicate there is an increase but it is not significant (P=0.2), while for iodine there is a decrease also it is not significant (P=0.1).T-test indicate no significant difference between them(P=0.07). Conclusion: Hardness of nylon denture base material increased by immersing in each of the ethanol and iodine but their increase is not significant (within 5 min.). Surface Roughness of nylon denture base material increases by immersing in ethanol alcohol while it decreases by immersing in iodine, this increase or decrease is not significant (within 5 min.).