| Objective:To verify the number of bacterial species and its types on the acrylic resin specimens after using four different methods of disinfection and evaluating the efficiency of several methods and for providing a theoretical basis of clinical procedure.Methods:30(30×20×2.6mm)acrylic resin specimens were made, 6 specimens were chosen as group B randomly. Based on"Disinfection Technology Standard", the group B was polished strictly executing aseptic manipulation. Bacteria specimens were collected from group B, cultured and calculated its bacterial species and numbers. The last 24 acrylic resin specimens were sent to the dental laboratories, polished by the routine method on the actual level of disinfection. After polishing, 24 acrylic resin specimens were divided into A, C, D, E groups randomly, each consisting of 6 samples. Group A, as the control group, from where bacteria specimens were cultured directly without any disinfection process. The groups C, D, E were disinfected by steam cleaning machine for 10 seconds, ultrasonic for 5 minutes, and soaked in 2%glutaraldehyde solution for 30 minutes respectively. Then bacteria specimens were taken for culturing and calculated the amount of bacterial species and its numbers. According to"Disinfection Technology Standard", KL=N0-NX,only after every time of KL≥3.00 it can be deemed to fulfilled the requirement of eligible disinfection. The data of experiment was analyzed by SPSS14.0 software, using t-test to estimate the disinfection effect between each group (P<0.05).Result:1.The average of colony count of the 2%glutaraldehyde and stream cleaning are less then 1,in other words, their groups KL more than N0;The control group's N0 is 3.53,and the Nx of group B and D are 1.86,1.38,their KL are 1.67,1.75, that means they are both less than 3.2.The t-test between control group and others indicated significant difference (P<0.05).3.By the pair wise comparison of the colony count of group B,C,D,E, they all have a significant difference(P<0.05) except 2%glutaraldehyde and stream cleaning(P=0.363).Conclusion:1.2%glutaraldehyde and stream cleaning are the eligible disinfection group, while ultrasonic and aseptic group are not.2.The 4 group's methods all have good effect to reduce the bacterial colony count.3.Most effective disinfection are 2%glutaraldehyde and stream cleaning, the next are ultrasonic and then aseptic group. |
