The effect of saliva and blood contamination on the bond characteristics of metal bracket bonded by light cured cyanoacrylate adhesive

Purpose: This study was aimed to evaluate the effect of saliva and blood contamination on shear bond strength of metal brackets bonded with light cured cyanoacrylate adhesive.
Material and methods: The study was conducted on 75 extracted upper first premolars. Metal orthodontic brackets were bonded to the buccal surfaces of the premolars using Smart bond LC adhesive. The teeth were divided into 5 equal groups. In group I no the teeth were not subjected to contamination. In Group II and III the same procedures were done as in in group I except that the etched enamel was contaminated by saliva and blood respectively for 15 seconds. In group IV and V the same procedures were followed as in group II and III except that the saliva and blood contamination were washed with water for 10 seconds. The shear bond strengths were recorded using universal testing machine. The amount of adhesive remaining on the tooth was evaluated after debonding. The collected data were statistically analyzed using One-way analysis of variance (ANOVA) and LSD tests.
Results: The results revealed that no significant differences were found in the bond strength between the control group (without contamination), saliva contamination group without washing and saliva contamination group with washing (P>0.05). On the other hand, blood contamination significantly reduced the bond strength in comparison the saliva contamination or control groups (P<0.05). In addition, washing after blood contamination provided significantly higher bond strength than without washing (P<0.05).
Conclusion: Saliva contamination had no pronounced deleterious effect on the bond strength of Smart bond LC. On the other hand, blood contamination had pronounced deleterious effect on the bond strength. However, washing with water significantly reduced this effect.