Effect of open-sandwich vs. adhesive restorative techniques on enamel and dentine demineralization: An in situ study
Available online 11 July 2013
Abstract
Objectives
To assess in situ
the effect of different restorative techniques used with
fluoride-releasing materials on enamel and dentine demineralization in
the presence of a cariogenic challenge.
Methods
Thirty
human molars were prepared for 60 Class V cavities, with enamel and
dentine margins. The teeth were divided into four groups (n = 15):
L1 – open sandwich technique with a conventional glass ionomer cement
(GIC), L2 – open sandwich technique with a resin-modified GIC, A1 –
total-etch bonding with a fluoride-containing adhesive, A2 – total-etch
bonding with a nonfluoride-containing adhesive. All the cavities were
restored with a nanofilled composite. Fifteen volunteers used appliances
containing one specimen from each group. The cariogenic challenge was
carried out with a 20% sucrose solution 8×/day for 7 days. The specimens
were sectioned for microhardness test and EDS analysis at different
depths below the enamel and dentine margins (25, 50 and 100 μm) and
distances from the tooth-restoration interfaces (25 and 75 μm). The data
were analyzed by ANOVA and Games–Howell test (α = 5%).
Results
Both
GICs produced higher hardness in enamel at all depth-and-distance
combinations, but only L1 produced higher hardness in dentine (p < 0.05). L2 and A1 exhibited similar dentine hardness at 25 μm distance for all depths (p > 0.05).
L1 demonstrated significantly higher amounts of calcium in dentine than
the other groups, but had similar amounts in enamel to L2 and A1.
Conclusions
The
open sandwich technique using conventional GIC proved more effective in
reducing enamel and dentine demineralization at depths of up to 100 μm
under a cariogenic challenge.
Clinical significance
Conventional
GICs should be considered the materials of choice for lining of
cavities not having all margins in enamel, particularly using the open
sandwich technique.
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