Micromorphology of grounded or ungrounded primary enamel in function of the etchant

Abstract

The aim of this study was to examina te under scanning electron microscopy (SEM) the micromorphology of grounded and ungrounded primary enamel after conditioning with 37% phosphoric acid, single or two-step self etching adhesive systems. Fiftheen primary teeth were selected and divided into three groups (n=5), according to the etchant and then sub-divided maintaining the enamel surface ungrounded or grounded. G1: 37% phosphoric acid (Condicionador Dental Gel – Dentsply). G1A: ungrounded enamel. G1B; grounded enamel. G2: etching with primer of a two-step adhesive system Adhese (Ivoclar – Vivadent). G2A: ungrounded enamel. G2B: grounded enamel. G3: etching with a single-step adhesive system (Xeno III – Dentsply). G3A: ungrounded enamel. G3B: grounded enamel. After enamel etching, all the samples were dehydrated, mounted on metal stubs and observed by SEM for etching pattern. G1A samples showed a non-uniform pattern of enamel etching (with etched and unetched areas). In G1B samples it was observed an uniform Type 2 etching pattern, according Silverstone etal. (1975). G2A and G2B samples did not reveal an uniform etching pattern, for both grounded and ungrounded enamel. It was concluded that the use of phosphoric acid seems to be more suitable to create a micro retentive surface, specially when enamel surface was grounded. Use of a self etching adhesive system on grounded or ungrounded primary enamel did not propitiate the formation of a microretentive enamel pattern.