The effect of moisture and blood contamination on bond strength of a new orthodontic bonding material.

The practice of orthodontics often requires the bonding of brackets under difficult conditions of moisture and/or blood contamination. Transbond MIP (3M Unitek, Monrovia, Calif) is a hydrophilic primer designed to bond in moist conditions. This study evaluated the bond strength of Transbond MIP under dry, moist, and blood-contaminated conditions. Ninety human premolars were bonded in 3 equal groups with Transbond MIP after acid etching; the enamel surfaces were either dry, moist, or contaminated with human blood. The shear bond strength was recorded. Dry bonding resulted in a significantly higher bond strength (15.69 MPa) than moist (12.89 MPa) or blood-contaminated (11.16 MPa) bonds. However, all bond strengths were in excess of previous reports of required clinical bond strength, and it was concluded that Transbond MIP is a suitable adhesive for bonding in conditions of poor moisture control or blood contamination.