Purpose: The aim of this laboratory study was to evaluate the marginal sealing ability of four glass-ionomer cements in cervical restorations (Class V) using dye penetration. Two conventional (C-GIC) and two resin-modified (RM-GIC) cements were used either with or without dentin conditioning with polyacrylic acid.
Materials and methods: 96 cervical cavities of standardized size were prepared in vitro in the vestibular and lingual portions at the cementoenamel level of 48 premolars. The coronal margins were prepared in enamel, the apical margins were localized in dentin. The 96 cavities were randomly divided into 4 groups of n = 24 each. The cavities of each group were filled with one of the test materials, and only half of the cavities received a dentin conditioning for 20 s with polyacrylic acids before filling. The fillings were finished with a set of abrasive disks 24 h after setting. The restored teeth were stored in saline for 4 weeks and subjected to dye penetration. The depth of dye penetration along the coronal and apical margin was measured on 4 longitudinal sections of each tooth with a semi-automatic image analysis system at 40x magnification.
Results: Mean depth of dye penetration ranged from 0 (ChemFil superior without conditioner) to 0.13 mm (ChemFil superior with conditioner) at enamel sites, and from 0.02 (Fuji II LC with conditioner) to 0.74 mm (ChemFil superior with and without conditioner) at dentin sites.
Conclusion: The conditioning of the cavities before filling improved the marginal adaptation significantly only in the Ketac-Fil group. Conventional glass-ionomer cements (C-GIC) in general demonstrated a lower sealing ability than the light-activated, resin-modified cements (RM-GIC). The adaptation of Photac-Fil quick is best without pretreatment--as recommended by the manufacturer.