4,9 However, conventional GICs also have a number of drawbacks that limit their indication for permanent restoration in primary teeth. In particular, GICs are advisable only in non-to-moderate stress bearing areas.10 As such, class II conventional GIC restorations show significantly shorter longevity in primary molars compared to those restored with resin-modified sellckchem GICs and compomers.11 Marginal deficiencies, wear, and secondary caries are other considerations that jeopardize the long-term performance of GIC restorations in primary teeth.12,13 Resin-modified GIC and high-viscosity GICs have been developed in an attempt to overcome the inherent physical shortcomings of conventional GIC. Today, both restorative materials have been established in pediatric practice, and their favorable longevity as a permanent restoration in primary teeth have been demonstrated in several clinical studies.
14,16 Recently, glass carbomer cement, a GIC-based restorative material, has been introduced with claims of improved physical characteristics. This new material contains nanosized powder particles and fluorapatite as secondary filler. The reactive glass is treated with dialkyl siloxanes described in the European Patent 20040748628. The rationale for the addition of fluorapatite into the powder is based on previous work by Van Duinen et al,17 who demonstrated the in vivo chemical transformation of glass ionomer into a fluorapatite-like material in primary teeth. The liquid of glass carbomer is polyacrylic acid.
Similar to high-viscosity GICs, incorporation of nanosized filler particles into the glass carbomer cement may improve its compressive strength and wear resistance. As a final step, the manufacturer stipulates photopolymerization of this new material by using a number of light-curing sources with a high output range. Presumably, the initial setting of the glass carbomer with such units may increase the compressive strength of the material. Being a glassionomer based restorative, application of a surface protection may also aid in the improvement of surface characteristics and sealing properties of the glass carbomer cement. Because there is no published data on the clinical use of glass carbomer cements, laboratory testing of the material may provide valuable insights into the physical properties of the material, particularly in primary teeth.
Consequently, the aim of this study was to evaluate the microleakage and marginal integrity of the newly developed glass carbomer cement with and without protective surface coating in primary molars. The null hypothesis tested was 2-fold: (1) the microleakage and marginal integrity of glass carbomer cement was not influenced by the application of protective surface coating (SC), and Anacetrapib (2) there was no difference between the sealing efficiency of glass carbomer cement, conventional GIC, and polyacid-modified resin composite in primary molars.