Study On The Abrasion Resistance Of A New Type Of Antibacterial Dental Light-curing Composite Resin Containing Nano-magnesium Oxide

Objective:On the basis of the antibacterial experiment of nano-MgO in this research group,the abrasion performance of a new antibacterial composite resin with different proportions of nano-MgO was studied.It provides theoretical basis for the development of new antibacterial dental light-cured composite resin and its clinical application.Methods:Before the inorganic filler?SiO₂?is used,a surface treatment is required,and the treatment agent used is a coupling agent-KH-570.Bis-GMA and TEGDMA were used to a matrix resin.CQ and DMAEMA were photocurable initiators,and the surface treated SiO₂was inorganic filler with a mass fraction of 1%,2%,4%and 8%nano-MgO antimicrobial agents,the composite resin without nano-MgO as control group,the composite resin needed for the synthesis experiment.This experiment was divided into the following groups according to the previous antimicrobial test of nano-MgO:group A:control group?without nano-MgO?,group B:1%,group C:2%,group D:4%,group E:8%.The photocurable composite resin containing different proportions of nano-MgO and two common clinical composite resins,charisma and AP-X^TM,were prepared into a cylinder wear-resistant specimen with a diameter of 10mm and a height of 6mm respectively.The cylinder wear-resistant specimenas were fixed on the DMW-1 wear tester.The wear load was 172N with rubber plate as the opposite grinding material and fluorite powder paste as the wear medium.At 100,200,400 and 800 times of wear,the volume loss?mm³?of the specimen is calculated by weighing,and the height loss??m?of the specimen is measured by the digital display meter.Then,the surface wear morphology was observed by SEM.The data of height loss and volume loss were analyzed by SPSS software,and compared with each other by LSD-t test,the test level was?=0.05,and the height loss and volume loss were analyzed by Pearson correlation coefficient.Results:There was no significant difference in volume loss and height loss between group B with 1%nano-MgO and group A without nano-MgO?P>0.05?.The volume loss and height loss of group C,group D,group E with 2%,4%,8%nano-MgO were significantly lower than group A without nano-MgO?P<0.05?.In terms of volume loss and height loss,there was no significant difference between group C,group D and group E?P>0.05?.There was no significant difference in volume loss and height loss between group D with 4%nano-MgO and charisma,AP-X^TM?P>0.05?.The correlation analysis of volume loss and height loss was carried out for each group of resins.The results showed that the r value was close to 1,the correlation between volume loss and height loss was heighter.There was statistical significance?P<0.05?.Therefore,it can be considered that the volume loss and height loss are significantly correlated.Conclusion:The new antibacterial dental light-cured composite resin containing 4%nano-MgO antibacterial agent has good wear resistance and can meet the clinical needs.Combined with the results of the previous nano-MgO antibacterial test,the antibacterial rate of the composite resin added with 4%nano-MgO is 95.5%.It has strong antibacterial effect,and its mechanical properties meet the clinical requirements.Light-cured composite resin containing 4%nano-MgO antibacterial agent is the best choice for preparing antibacterial composite resin.