Enhanced retention of glass-ionomer sealant by enamel etching: a microleakage and scanning electron microscopic study.
OBJECTIVE
A microleakage study and a scanning electron microscopic investigation were conducted to test whether etching of enamel would improve adhesion of glass-ionomer cement sealants to fissure enamel.


METHODS
Forty-eight extracted human molars and premolars were divided into 2 equal groups, and their crowns were cleaned with pumice. In group 1 enamel was etched for 45 seconds with 37% phosphoric acid. In group 2, enamel was not etched. Glass-ionomer sealant was applied to all 48 teeth. Twenty teeth from each group were thermocycled in water (120 cycles between 0 degree C and 56 degrees C) and stained with 0.5% methylene blue solution. The remaining 4 teeth from each group served as a control for the scanning electron microscopic evaluation. Twelve teeth from each group were cut into 5 sections, and 12 were cleaved into 3 sections in a buccolingual direction.


RESULTS
Statistically significant differences in amounts of microleakage were found between group 1 and group 2. Minimal microleakage was detected in 90% of the etched teeth, whereas extensive microleakage was observed in 85% of nonetched teeth. The scanning electron microscopic evaluation correlated positively with the microleakage observations. The etched teeth revealed a cohesive failure within the sealant material, while the nonetched teeth demonstrated an adhesive failure at the sealant-enamel interface. Observation of the nonthermocycled teeth confirmed those findings.


CONCLUSIONS
Results suggested that etching prior to application enhances the bonding of glass-ionomer sealant to fissure enamel.
Birkenfeld
L H
LH
Department of Pediatric Dentistry, New York University, College of Dentistry, New York 10010, USA. birkenfld@is2.nyu.edu
Schulman
A
A
D000134:Acid Etching, Dental; D001641:Bicuspid; D003743:Dental Enamel / Q000187:drug effects / Q000648:ultrastructure; D003750:Dental Fissures / Q000628:therapy; D003763:Dental Leakage / Q000517:prevention & control*; D005899:Glass Ionomer Cements; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008963:Molar; D010756:Phosphoric Acids / Q000494:pharmacology; D010895:Pit and Fissure Sealants
D005899:Glass Ionomer Cements; D010756:Phosphoric Acids; D010895:Pit and Fissure Sealants; C030242:phosphoric acid