Objective:  The purpose of this study was to determine dentin bonding agent (DBA) curing sequence effect on marginal fit of an indirect composite restoration.

 

Materials and Methods:  A master inlay die (MOD) was reproduced in high-heat epoxy material (Viade Inc.)  Composite inlays were made according to manufacturer specifications from Tescera ATL (BISCO, Inc.).  Thirty test specimens were divided into three groups of ten; pre-cured DBA, simultaneously cured DBA, and a control group using no DBA.  Four measurements of marginal gap width were recorded for each die prior to cementation; two on each surface (mesial/distal).  These measurements were made at pre-determined points along the restoration margin using a light microscope at 10X magnification.  All specimens were cemented according to manufacturer specifications with Nexus II cement and OptiBond Solo Plus DBA (Kerr USA).  The first ten inlays were seated after polymerization of the DBA.  In the second group, the DBA was cured simultaneously with the cement at the time of seating.  The control group was cemented without DBA.  Four post-cementation measurements per cemented die were made again.  The two gap width values for each tooth surface were averaged.  A mean difference was calculated for each test group and analyzed for significance using one way ANOVA and Tukey multiple comparison test.

Results:

		Pre-Cured DBA	Simultaneously Cured DBA	No DBA
Gap Width Difference (µ)	Mesial	105 (72)	61 (15)a*	41 (65)a
	Distal	157 (67)	40 (21)b*	61 (94)b

*Values with the same superscript are not significantly different

Conclusions: The study showed curing of the dentin bonding agent prior to cementation resulted in a significantly higher gap width value. 

This study was funded by AADR and the University of Michigan School of Dentistry.                .