3 research outputs found
Laboratory evaluation of the effect of unfilled resin after the use of self-etch and total-etch dentin adhesives on the Shear Bond Strength of composite to dentin
Background: Based on the frequent application of composite resins as tooth-colored fillings, this method is
considered a viable alternative to dental amalgam. However, this method has the low bond strength of the
composite to dentin. To solve this issue, various dental adhesive systems with different characteristics have been
developed by dentistry experts.
Aim: To assess the effect of an additional layer of unfilled resin in self-etch and total-etch dentin adhesives on
the shear bond strength (SBS) of composite to dentin. Moreover, we assessed the effects of sample storage in
artificial saliva on the SBS of composite to dentin.
Methods: Methods: This experimental study was conducted on 160 freshly extracted human first or second
premolar teeth, which were randomly divided into 16 groups. The teeth were prepared from Mashhad University
of Medical Sciences, Mashhad, Iran (2008-2009). Scotchbond Multi-purpose (SBMP), single bond (SB), Clearfil
SE Bond, and Clearfil S3 Bond were applied to dentin surface with or without the placement of hydrophobic
resin (Margin Bond) in accordance with the instructions of the manufacturers. To expose the coronal dentin, the
teeth were abraded with 600 grit SiC paper. Immediately after restoration, half of the samples were tested in
terms of SBS, while the other samples were evaluated in terms of SBS after three months of storage in artificial
saliva. SBS rates of dental composites evaluated by universal testing machine and samples were studied by
optical stereomicroscopy to verify the failure type. Data analysis was performed in SPSS V.16 using
Kolmogorov-Smirnov test, independent-samples t-test, ANOVA, and Duncan’s logistic regression test.
Results: In this study, a significant reduction was observed in the SBS rates of SB and S3 bond adhesive systems
after storage with and without hydrophobic resin (p>0.000). Without storage in normal saline, a significant
increase was observed in the SBS rate of the SE bond (p=0.013). In addition, SBS rate of SBMP significantly
increased after storage with hydrophobic resin (p=0.001). Finally, the highest and lowest rates of SBS were
observed in the SE and S3 bonds in all the experimental groups, respectively.
Conclusion: The effects of using a hydrophobic resin layer on shear bond strength values seem to be effective.
The mild self-etch adhesive exhibited the best resin-dentine bond strength after agin