Effect Of Tetracycline Enamel On Adhesive Strength Of Two Adhesives

Objective by studying the acid etching adhesive and corrosion from acid binder to tetracycline tooth enamel and enamel shear stress and normal tensile force,evaluation of the same kind of adhesive system for tetracycline tooth enamel and the difference of normal tooth enamel adhesive strength,with whole etched by tetracycline tooth enamel bonding agent and when the acid etching adhesive tensile force and shear force,evaluation of different adhesive system for the difference of tetracycline tooth enamel bonding strength,and laser confocal microscopy observation of tetracycline teeth and normal enamel resin glue on the surface of the junction after fracture microstructure,for tetracycline in clinical provide experiment basis for the selection of tooth enamel adhesive.Methods selection for the crowns of the orthodontic removal is complete without decay from devices for molar,choose 40,tetracycline tooth development 40 normal teeth,a total of 80 teeth,set the tetracycline teeth as the experimental group,the normal tooth as the control group,experimental group and control group randomly divided into the tensile and shear group,each group 20 teeth,and buccal tooth enamel use full pickling adhesive system(Prime & Bond NT),lingual enamel use since the acid etching adhesive system(SE-Bond).Shear group:In vitro teeth with superhard gypsum in making good the moulds embedding,tooth neck above enamel lip buccal and lingual palatal side not the embedding,make its in exposure condition,using silicon carbide burs grinding tooth enamel enamel surface is 0.5 mm,with tape in good tooth enamel surface polishing,ensure that exposed a width of 2 mm x 3 mm rectangular enamel surfaces,respectively,with the acid corrosion dope Prime & Bond NT and the acid corrosion dope SE-Bond adhesive,with 3m-Z350 slice stoping and backfilling layered composite resin curing,A resin block with a volume of 2×3×2mm~3 was prepared and stored in a constant temperature water bath for 24 h.Stretching group: use a uniform grinding emery car in addition to the 0.5 mm thickness of enamel,enamel surface of tape will be prepared in enamel surface,exposing a long 3 mm wide,2 mm of rectangular enamel surface,enamel buccal side use full pickling dope Prime & Bond NT for bonding,lingual enamel with the acid corrosion dope SE-Bond adhesive,both use the 3m-Z350 slice stoping and backfilling layered composite resin curing,to produce a volume of 2 x 3 x 2 mm after resin piece,finally to the preparation of good tetracycline tooth and tooth normal specimens in 37 ℃ deionized water stored in 24 h.The tensile force and shear force of the specimens were tested by universal material testing machine,and the tensile strength and shear strength were calculated according to the formula,and the bonding strength was studied.The fractured specimens were stained with 1g/L rhodamine B fluorescent dye,and the stained adhesive surfaces were placed under a laser confocal microscope(LSCM)to observe the ultrastructure of the specimen.Results(1)The tensile strength and shear strength of Prime & Bond NT adhesive on normal enamel were both higher than that of tetracycline enamel,with statistical significance(P < 0.05).(2)The tensile strength and shear strength of SE-Bond adhesive on normal enamel were both higher than those on tetracycline enamel,with statistical significance(P < 0.05).(3)The shear strength and tensile strength of tetracycline enamel treated with Prime & Bond NT adhesive were both higher than that treated with SE-Bond adhesive,with statistical significance(P < 0.05).(4)The results of laser scanning confocal microscopy showed that the crystal arrangement of the enamel of normal teeth was denser than that of tetracycline teeth,and the crystal arrangement of tetracycline teeth was more loosely.When the same adhesive system was used,the demineralization of the adhesive surface of the etched tetracycline teeth was more serious than that of normal teeth,showing uneven state.When different bonding systems were used for tetracycline enamel,it was observed that the demineralization degree of the self-etched adhesive interface was lighter than that of the total etched adhesive interface,and the total etched adhesive interface was more uneven and the bonding area was larger than that of the self-etched adhesive interface.Conclusion 1.For the bonding strength of tetracycline enamel,the total etching system is better than the self-etching system.2.The bonding strength of tetracycline enamel was lower than that of normal enamel in the total etching bonding system and the self-etching bonding system.