The Effect Of Adding Different Antimicrobial Agents On The Related Physical Properties Of Dental Stones

Objectives:To study the anti-bending strength, dimensional changes and the representation of surface bubbles of the dental gypsum models, which are made from the mixture of plaster and different kinds of antimicrobial agents, including 500mg/L, 1000mg/L Jianzhisu disinfectant,0.5% povidone-iodine, oral disinfectant, potassium permanganate disinfectant, 0.5%,1% IONPURE. And to study the disinfection effect of the gypsum models containing disinfectants toward streptococcus mutans and Candida albicans.Methods:8 groups of experimental materials were prepared, such as the mixtures of plaster and 7 kinds of disinfectants, and a control group of pure plaster.2 kinds of plaster were included, which were the ultra-anhydrite and anhydrite commonly used in clinical practice. The 7 kinds of disinfectants were 500mg/L, 1000mg/L Jianzhisu disinfectant, 0.5% povidone-iodine, oral disinfectant, potassium permanganate disinfectant,0.5%,1% IONPURE. Rectangular ceramic molds, three unit fixed bridge plexiglass molds and individual trays were made previously. (1)The rectangular ultra-anhydrite and anhydrite models with different disinfectants were respectively casted. Then the universal testing machine was used to test the anti-bending strength of the gypsum models, and the microscope was used to count the visible surface bubbles. (2)The three unit fixed bridge models of ultra-anhydrite and anhydrite were made, and their three-dimensional size changes were evaluated by measuring the the distances between landmark points on the plaster model surfaces using universal tool microscope. (3) The rectangular molds artificially infected by the streptococcus mutans and candida albicans. The plaster of experimental groups and control group was respectively casted in the molds.1 hour later, the models were demolded. Then they were immersed and agitated in the buffer liquid. A fixed amount of buffer liquid was removed from each groups, the bacterial colonies of which were immediately counted after cultivating 24 hours. The experimental data were analyzed statistically.Result:1. The disinfection effect of anhydrite on streptococcus mutans and Candida albicans at experimental and control groups.500mg/L Jianzhisu had good disinfection effects to Candida albicans, but for streptococcus mutans it only were inhibited and it cannot reach to the disinfection effects; 1000mg/L Jianzhisu and 0.5%IONPURE not only had good disinfection effects to Candida albicans, but also inhibit 97.7% streptococcus mutans; the experimental group of 5% povidone-iodine, oral disinfectant and 1% IONPURE had good disinfection effects to streptococcus mutans and Candida albicans; the group of potassium permanganate disinfectant just could inhibit Candida albicans and streptococcus mutans.2. The effects of the anti-bending strength of the ultra-anhydrite and anhydrite processed by experimental and control groups.There was no distinguished difference of the anti-bending strength of the ultra-anhydrite and the anhydrite after was blended by the disinfectant of 500mg/L and 0.5% IONPURE compared with control group(P>0.05); there was distinguished difference of the anti-blending strength of the ultra-anhydrite and the anhydrite after being blended by povidone-iodine compared with control group(P<0.05); there was distinguished difference of the anti-bending strength of the ultra-anhydrite after was blended by oral disinfectant, potassium permanganate disinfectant and 1%IONPURE compared control group, respectively(P<0.05). 3.The effect of the representation of surface bubbles of ultra-anhydrite and the anhydrite at experimental and control groups.There was no distinguished difference of the number of the surface bubbles of the ultra-anhydrite and the anhydrite concreted after 24 hours between experimental groups which was blended by 500mg/L Jianzhisu and potassium permanganate disinfectant and control group(P>0.05); there was distinguished difference between experimental group processed by 1000mg/L Jianzhisu, povidone-iodine, oral disinfectant,0.5% and 1%IONPURE (P<0.05). The surface bubbles of the groups of 1000mg/L Jianzhisu, oral disinfectant,0.5% and 1% IONPURE are few compare to the control group.4. The effects of dimensional changes of the ultra-anhydrite and the anhydrite processed by experimental and control groups.There was no distinguished difference at BL,MD,IP and OG direction of the ultra-anhydrite blended by 500mg/L Jianzhisu disinfectant (P>0.05); there was distinguished difference at BL and OG direction between experimental group of the ultra-anhydrite processed by 1000mg/L Jianzhisuand control group(P<0.05); there was distinguished difference at BL direction between experimental group of the ultra-anhydrite processed by povidone-iodine, oral disinfectant, potassium permanganate disinfectant(P<0.05); there was distinguished difference at MD direction between experiment group of the ultra-anhydrite processed by 0.5%IONPURE and control group, while the ultra-anhydrite processed by 1%IONPURE at BL and IP direction(P<0.05).There was no distinguished difference at BL,MD,IP and OG direction between experimental groups of anhydrite processed by 500mg/L 1000mg/L Jianzhisu, oral disinfectant, potassium permanganate disinfectant,0.5%,1%IONPURE; there was distinguished difference at OG direction between experimental group of anhydrite processed by povidone-iodine and control group(P<0.05).Conclusion:1. The disinfection effect of Jianzhisu disinfectant, povidone-iodine, oral disinfectant, and IONPURE disinfectant on streptococcus mutans and Candida albicans is satisfactory2. Anhydrite and super-hard gypsum added with both 0.5%IONPURE and 500mg/L Jianzhisu disinfectants have good disinfection effect, and can meet the requirements of clinic in the anti-bending strength, surface bubble, three-dimensional size of gypsum. So they can used for clinic properly.3. Povidone-iodine, oral disinfectant and potassium permanganate disinfectant are not appropriate to add to gypsum for clinical use.