Comparative Study Of The Effects Of Chitosan And Sodium Fluoride On The Biological Activity Of Streptococcus

Objective:In recent years,with the rapid development of economic level and rising living standards,the number of people who receiving orthodontic treatment is increasing.And the result is the enamel demineralization caries rate is higher.The main reason for the caries removal is the increase of the number of Streptococcus mutants in the mouth of the patients.Therefore,selection and use of a safe and effective antibacterial agent and natural non-toxic has become a research hotspot in recent years.The aim of the experiment is to utilize bacteria suspension and constructing the model of bacterial biofilm,preliminary detection and observation of Chitosan on the deformation of the inhibitory effect of Streptococcus S.Mutans ATCC25175,and with the inhibitory effect of sodium fluoride for comparison,so as to provide theoretical and experimental basis for the clinical application of chitosan.Methods:(1)By using different concentrations of chitosan and sodium fluoride,the inhibitory effect of mutans S.suspension was observed.The experiments were divided into three groups:control group(0.9%normal saline),chitosan(0.01%,0.03%,0.05%,0.1%,0.3%,0.5%)and sodium fluoride(0.01%,0.03%,0.05%,0.1%,0.3%,0.5%).Bacterial count was carried out and the bacterial growth status was observed.(2)MTT method was used to detect the absorbance value of bacteria at different concentrations,and to determine the bacterial activity and value added.(3)Using the PH tester to detect,calculate PH,reflect the change of the number of bacteria by pH change.Results:(1)Colony plate count method showed that the colony number of Mutans S.was significantly decreased(P<0.05)in chitosan group and sodium fluoride group compared with normal saline group.It was found that the number of mutans S.colonies decreased with the increase of the concentration of drugs.(2)The results of MTT test showed that there was significant difference between the chitosan treatment group and the saline control group(P<0.05),but there was no significant difference between chitosan group and sodium fluoride group(P>0.05).(3)Chitosan and sodium fluoride can inhibit the bacterial acid production,reduce the decline of PH,so that the final pH value is higher than the initial PH,but the role of chitosan is weaker than that of sodium fluorideConclusion:(1)Both CTS and NaF can inhibit the growth of s.Mutans.(2)Compared with two kinds of drugs,the inhibitory effect of CTS was similar to NaF.