Clinical Comparative Study Of The Impact Of Pretreatment Effect With 2% Chlorhexidine On Composite Resin Bond Retention

Objective: The aim of this study was to evaluate the impact of 2% chlorhexidine on the composite resin bond retention,to compare the effect of dentine pretreatment with2% chlorhexidine in clinical cases with conventional composite resin bonding repair method,so that it could provide certain basis for the clinical application of chlorhexidine,as pretreatment agent.Methods: For the 18 patients that met the inclusion criteria,each had a pair of obvious wedge-shaped defective teeth at the same time.There were a total of 36 diseased teeth.They were randomly divided into experimental group with the pretreatment of 2% chlorhexidine and control group,with 18 diseased teeth in each group.All patients were physically fit,could express clearly,and actively cooperated with treatment;had good oral hygiene,no red gums,fair occluding relation,and no closing interference,partial lateral chewing and night molar habit;their diseased teeth had no history of treatment,no spontaneous pain,no occluding pain;and tooth vitality was normal and no loosening;the obvious edge-shaped defect at the tooth neck lip buccal side reached dentin layer,with the depth of 1~2mm;patients' pain degree was level 0(classified according to the subjective feeling of patients).Besides,systemic disease and the diseases affecting the accuracy of the observation indexes,such as poor babble condition,swollen gums,tooth decay,pulpitis and apicitis were excluded.Firstly,the author gently grinded tooth enamel and dentin on the defective part with slow mobile phone to make them expose fresh surface,and then prepared a short slope with the angle of 45 degrees on the edge of the tooth enamel with fast mobile phone,thoroughly rinsed defective surface layer with water,and closely separated the diseased teeth from wet with lap.Secondly,the experimental group: the author dried tooth surface with no water/oil air gun,evenly rubbed wedge-shaped defective surface with adhesive stick dipping with 2% chlorhexidine,kept it for 30 s,gently blew the defectivesurface with no water/oil air gun to lightly wet state,evenly applied self-etching adhesive Adper Easy One with bonding bar for 20 s,gently blew the surface for 5s,made it receive light for 10 s,filled with 3M-Z350 composite resin,made it receive curing light for 20 s,ensured the thickness of each layer was less than 2mm,and finally polished it.Control group: the author didn't treat the dentin surface,blew bonding surface with no water/oil air gun to slightly wet state,evenly applied self-etching adhesive(Adper Easy One)with hairbrush to the defective surface for 20 s,lightly blew the surface for 5s,made it receive light for 10 s,filled with 3M-Z350 composite resin,made it receive curing light for 20 s,ensured the thickness of each layer was less than2 mm,and finally polished it.If the defective part was below the gum margin,gingival retraction was first conducted and then filling treatment was executed.The patients were asked to reexamine in the 6th month and 12 th month and immediately reexamine if filling body loosened,fell off,and had teeth discomfort.Independent analysis was adopted for the sensitive indicators after diseased tooth filling.The clinical conditions of resin restoration were examined through visual examination and diagnosis;the modified USPHS resin restoration evaluation standard quantitative table was used to record the composite resin edge dying,edge sealing,anatomical morphology and secondary caries,with the level of A,B,C and D.Next,the rank sum test and inspection was conducted on the ranked data of two samples.Results: all diseased teeth are not sensitive before and after operation.In 6 months of composite resin filling,one diseased tooth resin filling body of the control group completely falls off,there are six failure indicators.All of experimental group is successful.In the 12 months,there are 7 failure indicators in the control group.All of experimental group is successful.In 6 months and 12 months of composite resin restoration,the therapeutic effect of the experimental group with the pretreatment of 2%chlorhexidine is significantly better than the control group.The therapeutic effect of two groups is significantly different(P<0.05).Conclusions: In the observation period of 6 months and 12 months,the composite resin bond retention of dentin pretreatment with 2% chlorhexidine is superior to that of control group.Dentin pretreatment with 2% chlorhexidine has positive roles on bond retention of composite resin.