Abstract
In this study were evaluated the chemical changes in enamel adjacent to four different composite resin restorations after their contact with hydrochloric acid. Twenty healthy molars were chosen for this study and class I cavities were prepared on occlusal surfaces. Four commercial composite resins were used for filling: Filtek Z250 (3M ESPE, USA), Filtek Ultimate (3M ESPE, USA), Herculite (SDS KERR, USA) and Point 4 (SDS KERR, USA). The samples were obtained by cutting the teeth in two halves. Some of the samples were maintained in distilled water as control group and the others were mentained for 30 min in 0,06 mol/L hydrochloric acid (pH = 1,2). The morphological aspect of the interface between enamel and composite resin was evaluated using scanning electron microscopy (SEM) and the mineral content (calcium, phosphorus, oxygen ions concentration) was assessed using EDX method. Chemical analysis showed significant changes of ions concentration both in enamel and in composite restorations. The enamel adjacent to Filtek Ultimate was less affected by the contact with hydrochloric acid when comparing to other composite resins. Keywords: gastroesophageal reflux disease (GERD), SEM microscopy, EDX method mineral content to enamel adjacent resin composite