Surface Characteristics of Hydroxy apatite and Adhesive Bonding. I. Surface Characterization

Abstract

Adhesion to hydroxyapatite (HA), the mineral phase of calcified tissues, is important in cellular attachment and bonding of synthetic adhesive materials. The surface preparation of HA was found to affect the adhesion greatly. A pure synthetic HA was studied to examine the effect of commonly-used preparative techniques on surface morphology and activity. Surface grinding and polishing and organic acid etching gave rough surfaces that were hydrophobic. Etching with HC1 or HN0₃ and firing at 800°C gave hydrophilic surfaces. ISS, SIMS and ESCA studies showed various degrees of organic and inorganic contamination. Plasma cleaning removed hydrophobic contaminants but inorganic contamination from the plasma vessel increased as time of exposure was increased. It was evident that current preparative procedures give highly variable surfaces that would be expected to influence adhesion of both monomer-polymer adhesive systems and cells.

Key Words:

• Adhesion
• dentistry
• morphology
• preparative techniques
• surface characterization
• synthetic hydroxyapatite.