title: Avaliação da microinfiltração marginal e profundidade de penetração dos cimentos de ionômero de vidro utilizados como selantes oclusais.
abstract: OBJECTIVE
  the aim of this study was to conduct an in vitro comparison of marginal microleakage (MM) and the depth of penetration (DP) of glass ionomer cements (GIC) and a resin sealant (RS) into occlusal pit and fissures.
  
  
  METHODS
  for that purpose, 60 intact third molars were equally distributed to 5 groups: G1 - 37% phosphoric acid / Delton; G2 - 40% polyacrylic acid / Ketac-Molar / nail varnish; G3 - Fuji Plus conditioner / Fuji Plus/ nail varnish; G4 -37% phosphoric acid / Vitremer / Finishing gloss; G5 -37% phosphoric acid / Vitremer prepared with a 1:4 ratio of powder / Finishing gloss. The teeth were submitted to a thermal treatment corresponding to 300 cycles (15 sec, 5/55(0)C), followed by complete coating with nail varnish, except for 1mm beyond the contour of the sealant. Afterwards, the teeth were immersed in 0.5% basic fuchsine for 24 hours. Thereafter, the teeth were sectioned in buccolingual direction and microscopically analyzed (150x magnification) by means of predetermined scores. The results were subject to the Kruskal-Wallis test.
  
  
  RESULTS
  there was no statistical difference between the materials tested in relation to the DP, being that all groups displayed nearly complete filling of the fissures. No sealant material was able to prevent dye penetration; however, the GICs provided better results of MM, with significant difference when compared to the RS.
  
  
  CONCLUSIONS
  all materials investigated presented a satisfactory degree of penetration into the fissures; however, the glass ionomer cements displayed better performance in the marginal microleakage test compared to the resin sealant.
authors.affiliation: Department of Pediatric Dentistry, Bauru School, University of São Paulo, São Paulo, Brazil.
authors.forename: Marina de Lourdes Calvo
authors.initials: Mde L
authors.lastname: Fracasso
authors.forename: Daniela
authors.initials: D
authors.lastname: Rios
authors.forename: Maria Aparecida Andrade Moreira
authors.initials: MA
authors.lastname: Machado
authors.forename: Salete Moura Bonifácio da
authors.initials: SM
authors.lastname: Silva
authors.forename: Ruy César Camargo
authors.initials: RC
authors.lastname: Abdo