Effect of self-etching prime/adhesive on bond strength of ceramic orthodontic brackets

Zhanqin CUI; Lihua SHAN; Haili HUAI

ABSTRACT

BACKGROUND:

The shear bond strength between ceramic orthodontic brackets and teeth is so large that ceramic brackets are not easily eliminated safely. Whether the shear bond strength of self-etching primer/adhesive can be decreased and the injuries to enamel can be reduced has been always concerned by orthodontists.

OBJECTIVE:

To evaluate the bond strength between self-etching primer/adhesive system and ceramic orthodontic brackets and make a comparison with Jingjin enamel adhesive most commonly used by clinicians in China.DESIGN, TIME AND

SETTING:

Controlled observation, performed at Hebei University of Science and Technology in March 2006.MATERIALS Twenty permanent premolars extracted due to orthodontic treatment were selected. The premolars were required to have excellent enamel and gloss, no cracks or carious lesions, and have not been given any chemotherapy. Ceramic orthodontic brackets were arch wire ceramic premolar brackets with 0.022-inch standard edgewide (3M company,USA). The bottom bracket area was 12.16 mm2. Self-etching sealant and TransbondTM fight-cure adhesive were purchased from 3M company, USA. Jingjin enamel adhesive, a conventional self-etching adhesive, was provided by Tianjin Institute of Synthetic Materials Industry, China.

METHODS:

The 20 premolars were randomly evenly divided into a self-etching primer/adhesive group, in which,self-etching sealant and TransbondTM fight-cure adhesive were applied, and a Jingiin enamel adhesive group, in which,Jingjin enamel adhesive was used.MAIN OUTCOME

MEASURES:

After 24 hours, shear bond strength was determined respectively in the two groups using anti-shearing testing machine. Simultaneously, residual adhesive remaining on the teeth was examined.

RESULTS:

The mean shear bond strength was lower in the self-etching primer/adhesive group than in the Jingjin enamel adhesive group, but there was no significant difference (P > 0.05). The mean shear bond strength in the two groups was clinically acceptable. The residual adhesive remaining on the teeth was significantly less in the self-etching prime/adhesive group than in the Jingjin enamel adhesive group (P < 0.01).

CONCLUSION:

Self-etching prime/adhesive system used for bonding ceramic orthodontic brackets can satisfy clinical requirements. Moreover, its bond strength can be appropriately decreased and ceramic brackets are easily removed, thereby,injuries to enamel can be reduced.