SEM Micromorphology Study Of Different Adhesive Systems On Adhesive-dentin Interface

Objective:To examine the microstructure of the adhesive interface between resin cement and dentintreated with four kinds of cement systems by SEM in order to clarify the adhesive efficiencies of four type of resin cement systems.Methods:45noncarious human molars from patients were sectioned to absolutely expose flat dentin surface.All teeth was randomly separated into5experimental groups(n=10),group NT,group AE,group SE,group SB,and the contrl group C.Group NT was applied Prime Bond NT according to the manufacturer’s instructions.Group AE was applied Adper Easy One,group SE was applied SE BOND and group SB was applied Sdper Single Bond follow the instructions.Group C was applied no adhesive.then3mm thickness of composite was built up on it.After setting the resin disk on the tooth surface with resin cement,the cement was light-cured surface with resin disk for40seconds by a light activator.After stored in physiological saline,the teeth was selected to obtain approximately1mm×1mm beams for observed.Every tooth was incised three piece and selected without microcrack.The vertical section of bovine teeth was polished with SiC paper(#600,1000,1500,2000) under running wanter.Group C was compared to incised about1mm thickness to observe the microstructure of normal dentin,self-etching。 All of these specimens for SEM observation underwent ultrasonic cleaning for3minutes after each treatment and were dried.Polished snd etched surfaces of specimens were sputter-coated with gold,and then observed using a scanning electron microscope at15kV.Results:The smear laying and resin tags can be observed between dentin and composite in these specimens.All teeth showed hybrid layer formation.However,the thickness varied depending on the adhesive systems and the total-etching(Prime&Bond NT and)showed the thick hybrid layer whereas SE bonded to dentin exhibited the thinner hybrid layer.Moreover,in the teeth which were used total-etching,the composite did not penetrate to the depth of the zone of demineralized dentin,leaving a substantial area of exposed dentin matrix at the dentin/cement interface.In contrast,there was substantial composite diffusion throughout the demineralized dentin when the self-etching prime was without acid etching pretreatment.The one-way analysis of variance showed a significant difference in the extent of date among the four groups (P<0.05).LSD-t test indicated that the thickness hybrid layer between group A and group B was not sratistically significant(P>0.05),else comparances was observed different(P<0.05).The length of tags between group A and group B was not sratistically significant(P>0.05),the same was group C and group D,else comparances was observed different(P<0.05).Conclusion:Good obturation appesred in self-etching groups.The resin tag and the tubules were open in total-etching groups.