Clinical Evaluation Of Composite Resin Nanoceramics Inlay Applied To Massive Defects Of Adolescent’s First Permanent Molars

Objective In recent years,Lava^TM Ultimate,a new composite resin nanoceramics,has been more and more widely used in the repair of adult tooth defects,but there are few reports on the application of composite resin nanoceramics to the massive defects of adolescent first permanent molar.In this paper,computer-aided design/computer-aided manufacturing（CAD/CAM）composite resin nanoceramics inlay was studied to repair the massive defects of adolescent first permanent molar,and compared with the traditional composite resin filling repair,so as to provide reference for the clinical application of new repair materials and new repair methods.Methods This study collected 82 adolescent first permanent molars that met the inclusion criteria in our hospital from December 2019 to December 2020.Firstly,82 first permanent molars were randomly divided into two groups:experimental group and control group.Among them,40 samples in the experimental group were repaired with composite resin nanoceramics inlay under CAD/CAM system;42 samples in the control group were filled with composite resin.Then,follow-up was conducted at the 6th and 12th months respectively.At each follow-up,the same researcher independently referred to the improved World Dental Federation（FDI）standards to score the two groups of restorations in three aspects:esthetic properties（surface luster,surface staining and margin staining）,functional properties（fractures and retention,marginal adaptability）and biological properties（postoperative sensitivity,recurrence of caries,erosion,abfraction）.Finally,SPSS 22.0 software was used to process the score data.Shapiro-Wilk test is used to detect the normality of measurement data,and Mann-Whitney U test is used to compare the age between groups;AndX~2test was used to compare the gender,tooth position and the improved FDI score of the restoration 6 and 12 months after the completion of the restoration.P<0.05 was statistically significant.Results A total of 82 first permanent molars were collected,including 36 maxillary first molars and 46 mandibular first molars.Among them,there were 47 male children and 35female children,age 14（13,15）.After 6 months of follow-up,the retention rate of prosthesis in the experimental group and the control group was 100%,and there was no significant difference in all aspects of prosthesis between the two groups（P>0.05）;After 12 months of follow-up,the retention rate of the restoration in the experimental group was 100%,but 2 cases in the control group fell off due to secondary caries,with a retention rate of 95.24%,in terms of esthetic properties,there was no significant difference in surface staining and edge staining between the two groups（P>0.05）,but there was significant difference in surface gloss（P<0.05）,and the score of experimental group was higher than that of control group;In terms of functional properties,there was no significant difference in marginal adaptation between the two groups（P>0.05）,but there was significant difference in fracture and retention（P<0.05）,and the score of experimental group was higher than that of control group;In terms of biological properties,there was no significant difference in postoperative sensitivity between the two groups（P>0.05）,but there was significant difference in recurrence of caries and abfraction（P<0.05）,and the score of experimental group was higher than that of control group.Conclusion In this study,the first permanent molars with massive defects in adolescents were repaired with composite resin nanoceramics inlay under CAD/CAM system,and its short-term clinical efficacy was compared with composite resin restoration.The conclusion shows that the clinical effect of composite resin nanoceramics inlay is better than traditional composite resin in terms of esthetic properties,functional properties and biological properties.Therefore,composite resin nanoceramics inlay can be used to repair them under the CAD/CAM system.