ABSTRACT
The aim of this study was to compare the shear bond strengths of orthodontic bracket with Conventional primer (CP), Moisture insensitive primer (MIP), and Self-etching primer (SEP). In addition, the effect and the timing of saliva contamination on shear bond strength was evaluated.A total of 135 bovine mandibular incisors were used in the study and divided into 3 groups. Group I, II and III were used CP, MIP, SEP, respectively. Each group was then divided into three subgroups: the group without saliva contamination, the group with primer application after saliva contamination, and the group with saliva contamination after primer application. After the primer application, the metal bracket for the lower incisor was attached and the shear bond strength was measured.The mean shear bond strengths was highest with CP and lowest with SEP in dry condition. However, CP showed a significant decrease in shear bond strength in the presence of saliva contamination. MIP and SEP showed no significant decrease in shear bond strength with saliva contamination.
Subject(s)
Incisor , Orthodontic Brackets , SalivaABSTRACT
Objective:To evaluate the effects of the flowable resin used as pit and fissure sealant using different etching adhesive systems.Methods:60 caries-free extracted human premolars were randomly divided into 4 groups(n =1 5)and treated by Gluma, NT and 3M-Z350 flowable resin(group A);Clearifil SE Bond adhesive and 3M-Z350 flowable resin(group B),phosphoric acid etching,3M-Z350 flowable resin and phosphoric acid etching(group C)and 3Mconcise sealant(group D)respectively.After pro-cessing the tooth surface the pit and fissue of 1 0 sample in each group were sealed.The microleakage was measured by 1 % methyl-ene blue staining(n =8).The material-enamel interface was observed by SEM(n =2).The shear bond strength of the column-shaped samples with the diameter and the height of 3 mm(n =5)on the mesial or dental surface was examined by a test machine. The sealant cartridges and flowable resin cartridges with the diameter and height of 4 mm were used for the crushing strength exami-nation(n =1 0).Results:There was no significant difference in the microleakage among the 4 groups.SEMobservation showed that the resin tags of group A were long and dense and the resin tags of group B were short and sparse,bubbles and cracks were found on the local site in group A and B.The resin tags of group C were long and thin,but combined with tooth tightly;the resin tags of group D were short and dense;the penetration was poor at the bottom of the fissures in the 4 groups.The shear bond strength of Group A was the highest(P 0.05).The compressive strength of flowable resin groups was higher than that of fissure seal-ant group(P <0.05).Conclusion:The shear bond strength and compressive strength of all-etching bonding system combined with flowable resin is superior to that of self-etching bonding system combined with flowable resin and the traditional sealant.Using Prime&Bond NT bond after acid etching may improve the shear bonding strength.
ABSTRACT
0.05);) Single Bond provided significantly higher shear bond strengths than Adper Prompt in all groups((P