Comparison of marginal adaptation of two dental composites

The shrinkage during polymerization of dental composites difficult the union with the dental tissues, especially with dentine. The material like ormocer composite was developed with the aim to minimize this contraction.

Objectives:

To compare the marginal adaptation of a conventional composite and an ormocer composite to dental tissues (enamel and dentine).

Methods:

40 Class V resin composite restorations were placed in prepared cavities in extracted teeth and was divided in four groups using : an conventional composite, Spectrum (Dentsply)(S) and Ormocer composite Definite(Dentsply) (D) y two diferents tiepes of etching dentin adhesive systems, Prime Bond (Dentsply) (PB) y Xeno III (Dentsply) (X) self-etching dentine adhesive. The distribution of each group was: First group S and PB, Second group, S and X, Third group, D y PB, Fourth group, D and X. With a scanning electron microscope (SEM) was observed the interface and measured the maxim gap in: enamel union, axial-oclusal angle, axial wall, axial-cervical angle, cervical wall. A descriptive analyse was done with group results and they were compared between them using a 2-way analysis of variance and Tukey multiple comparison. This analyse was completed with a Confocal Laser Microscopy (CLM) study of the penetration of dentine adhesives in dentinal tubules.

Results:

The ormocer improve a perfect union with enamel in all preparations. The union to dentine wall was less effective with a regular behaviour of Xeno III. Not statistically significantly differences was encounter comparing the adaptation to enamel and to dentine for the two groups

Conclusion:

The union between ormocer and enamel was perfect; the interface dentine-ormocer presents a minor gap than the conventional composite when is used with dentinal adhesive and total etch technique.