A comparative evaluation of microleakage among newer composite materials: An in vitro Study

Abstract

Background:Good adhesive bonding of restorative materials to cavity walls minimizing microleakage is an important criterion for the performance and longevity of a restoration in the oral cavity. The present study is aimed to compare the microleakage among newer composite materials.Materials and Methods:Forty-five extracted healthy premolars were collected; standard Class II cavities were prepared. They were randomly divided into three groups of 15 teeth each. The groups were made based on the different composite restorative materials used for restoration. Group A consisted of conventional microfilled composite resin restorations, and Group B was posterior nanocomposite resin. Group C was restored using ORMOCER – Admira. After completion of restorations, all teeth were subjected to thermocycling at 5° C, 37° C, and 55° C for 250 cycles. Later, all samples were immersed into 50% silver nitrate dye group wise for for 4 hours (h), and teeth were sectioned buccolingually. Sectioned teeth were observed under a stereomicroscope for the evaluation of microleakage. ANOVA and unpaired t-tests were used for statistical analysis. The significance level was at set P < 0.001.Results:The results of this study showed that Group C (ORMOCER – Admira) presented with the least microleakage followed by Group B (Tetric N-Ceram) followed by Group A (Tetric Ceram).Conclusions:Overall ORMOCER – Admira performed better than the other two composite materials with the least microleakage.

In Vitro Study on the Adhesive Performance of Some Resin-Based Materials Used to Restore Class II Cavities

“…The optimal adhesion of direct class II restorations to the dental structures depends on many factors [ 22 , 23 , 24 , 25 , 26 , 27 ] and is essential for providing good clinical outcomes and prevent restoration failure [ 7 ] or periodontal problems [ 12 , 28 ].…”

“…The relative equal performance of the materials may be due to the fact that the first generation of ormocer materials used in this study contain conventional methacrylate diluents, which may prevent to fulfil the expected potential [ 33 , 34 ], but similar shear bond strength [ 35 ], in vivo sealing ability and polymerization shrinkage are used [ 11 ]. The very recent dimethacrylate-diluent-free ormocer matrices seemed to improve ormocer behavior [ 7 ].…”

“…Posterior resin composites shrink between 2.6% and 7.1% by volume [ 6 ]. The extent of shrinkage is highly dependent on the filler load, and the treatment technique of filler particles [ 7 ]. Therefore, the properties of direct restorative filling materials require further improvement through compositional modifications in order to fulfil clinical requirements.…”

“…More filler particles increase the strength and modulus of elasticity and reduce polymerization shrinkage. Nanocomposites contain sub-micrometer particles (nano fillers), which improve particle distribution, filler loading [ 8 ] and their polymerization behavior [ 7 ].…”

“…A new generation material named ORMOCER (Organic-Modified Ceramic) was developed by manufacturers. Ormocer materials consist of inorganic–organic co-polymers having less polymerization shrinkage than conventional Bis-GMA-based composites [ 7 ] due to the larger three dimensional cross-linked ceramic polysiloxane monomer [ 11 ]. The volumetric polymerization shrinkage of ormocer materials was reported to be <2%, thus indicating a better marginal integrity [ 11 ].…”