Evaluation Of Microleakage In Three Flowable Materials For Permanent Molars With Preventive Resin Restoration:a Comparative Study

Objective To evaluate the performance of self-adhesive flowable composite in pit-and-fissure caries treatment,compared with the other two flowable filling materials.Methods 33 human premolar teeth extracted for orthodontic reason were collected.Class I cavity preparations simulate the in-vivo pit-and-fissure caries on premolar.Then the teeth were randomly divided into three groups（n=10）and restored using flowable filling materials,Group A:Self-adhesive flowable composite（A2）;Group B:Flow Plus composite F03（A2,low flow）;Groups C:Fuji VII glass ionomoer cement.After 1000 times thermocycling（5±2℃-55±2℃,dwell time=30s）,the prepared samples were immersed in 2%methylene blue solution for 48 hours.Finally using dental wheel cut every tooth in a buccolingual direction.The degree of dye penetration on sections was observed with a stereomicroscope.The operation time of each tooth were recorded by an assistant.3 sections from different group were chosen and washed:air dried and were attached to aluminum stubs and then sputtered with a2000E thick layer of gold under sputtering unit.Enamel interface between materials and tooth was evaluated under SEM with a magnification of×40^×1000.Kruskal-Willis H test and Mann-Whitney test were used for statistical analysis by SPSS 22.0.ResultsAmongst all,the resistence to microleakage of three materials were statistically different(?^（17）=18.902,P<0.01,Kruskal-Wallis H Test).DF self-adhesive flowable composite showed the least amount of microleakage,whereas Fuji VII glass ionomer cement scored the highest microleakage.But there was no significant difference between self-adhesive flowable composite group and F03 flowable composite group（P>0.05）.In addition,the operation time of F03flowable composite group was significantly more than both self-adhesive composite group and Fuji VII group（P<0.05）.ConclusionsThrough the experiment in vitro,both self-adhesive flowable composite and F03 flowable composite were better than Fuji VII glass ionomer cement in marginal adaptation,but no significant difference was found.If operation time was taken into consideration,self-adhesive flowable composite may show favorable availability in those who hard to tolerate longstanding treatment,especially the child.In addition,clinical prospective study is necessary to complement evidence.