Comparison Of Cleaning Effect Of Different Methods On Complete Denture

OBJECTIVE:This aim of this study was to evaluate effect of different methods on cleaning pigment and Candida albicans on heat curing acrylic resin using in denture base in vitro.METHODS:Sixty specimens(10x10×l.3mm) were dyed by coffee, tea and other pigmant from normal food. Then they were contaminated (37℃for 48 hours) by Candida albicans inoculum with 106 colony-forming units (CFU)/ml. Then, specimens were classed into 6 groups randomly and cleaned by the following methods respectively: (1) mechanical:brushing for 20 seconds; (2) chemical:immersion in an alkaline peroxide solution (Sushuang Denture Cleaning Tablets) for 10 minutes; (3) a combination of (1) and (2); (4) after ultrasonical cleaning, a combination of (1) and (2);(5) a combination of ultrasonical cleaning and brushing; (6) just washing by steriled distilled water. Afterward, the specimens were incubated in Yeast Extract Peptone Dextrose Medium (YPD) at 37℃for 24 hours. Then the concentration of Candida albicans inoculum in 1ml YPD was tested by spectrophotometer, and the effect of color removal was tested by Shade-Eye NCC (Shofu Dental Inc.) RESULTS:1,Removal of Candida albicans:Comparing with method (6),method(1),(2),(3),(4) and (5) had significant greater effect(p<0.01). There was no statistic difference between cleaning effect of method (2)and(5).The other methods have statistic differences between each other(p<0.01).2,Removal of pigment: Comparing with method (6), method(1),(2),(3),(4) and (5)had significantly greater cleaning effect(p<0.01). There are no significant differences between results of method (1)and method(4).So as (2) and (4). The other methods have statistic differences between each other(p<0.01).CONCLUSIONS:A combination of brushing, chemical cleanser and ultrasonic cleaning is the best method to clean Candida albicans as well as pigment. Ultrasonic cleaning is advised to be used regularly among persons with RPD.