Marginal adaptation of glass cermet restorations in primary molars

Abstract

Ketac-Silver and Chelon-Silver are reinforced glass ionomer cements which are intended principally for the restoration of primary teeth. Clinical evaluations using a mirrior and explorer are relatively crude, while indirect microscopic studies using replica dies can provide more detailed information. This study sought to quantify, in vivo, the marginal adaptation of Ketac-Silver, Chelon-Sliver and Dispersalloy amalgam which was used as a control. Contralateral pairs of carious lesions on primary molars, in 81 children aged between 7 and 9 years, were restored with the test materials on one side of the dental arch, the contralateral lesion being restored with amalgam. Polyether impressions of the restorations placed in 16 children were taken at 12, 18 and 24 months from which epoxy resin replica dies were prepared. Changes in the marginal adaptation were then observed using scanning electron microscopy. Measurements of cavomarginal breakdown were made directly from the SEM screen. The marginal adaptation of the material was assessed quantitatively using the marginal fracture Index (MFI). The MFI for Dispersalloy rose from 0.02±0.06 at baseline to 0.19±0.28 by 18 months; the corresponding values for Ketac-Sliver were 0.11±0.13 and 0.21±0.27 while for Chelon-Silver the values were 0.20±0.21 end 0.58±0.43. At 24 months the MFI for Chelon-Siiver was higher than for Ketac-Silver arnd Dispersalloy; however, It was not statistically significant.