K. OKUYAMA1, T. NAKATA2, C. KAWAMOTO2, P.N.R. PEREIRA1, H. KOMATSU2, and H. SANO2, 1 University of North Carolina at Chapel Hill, USA, 2 Hokkaido University, Sapporo, Japan
Objective: Fluoride (F) containing materials are
expected to inhibit caries progression. The purpose of this study was to
evaluate the effect of topical fluoride application to resin restorations on
artificial caries, by using a pH-cycling model that alternated demineralization
(D: pH4.5) and remineralization (R: pH7.0) solutions.
Methods: A F-containing bonding agent (Reactmer bond:
RB, Shofu), a non-F bonding agent (Clearfil SE Bond: SE, Kuraray), and two
resin composites, F-containing (Reactmer paste: RP, Shofu) and non-F (Clearfil
AP-X: AP, Kuraray) were used. A combination of each bonding and a
composite, RB/RP (RR), RB/AP (RA), SE/RP (SR) and SE/AP (SA), was filled in a
cavity on root dentin of extracted human molars (n=96). The pH cycling
was done on a daily schedule of three cycles of 1hr-D and 4hrs-R and followed
by 9hrs-R storage. Half of specimens were immersed into 0.05% NaF
solution for 1min. once a day as an F mouth-rinse simulation. After the
pH cycling for 6 or 12 weeks, outer lesion depths of specimens were
measured. The artificial caries lesion depths (µm) were analyzed by
one-way ANOVA and sheffe's test.
Results: Mean±SD: Values connected by same superscripts
are not significantly different (p>0.05). n=6
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6 weeks
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12 weeks
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Combination
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F-application(-)
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F-application(+)
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F-application(-)
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F-application(+)
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RR
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274.4±16.4a
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243.3±18.4b
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376.7±23.0c
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298.7±20.4
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RA
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282.1±22.1a
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244.8±23.4b
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411.1±18.3c
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347.2±18.6d
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SR
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269.0±13.5a
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245.1± 4.6b
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387.0±15.4c
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329.1±17.2d
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SA
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289.2± 9.3a
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231.0±17.4b
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404.5±23.8c
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333.0±15.0d
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Each combination with F-application had lower
caries lesion depth than that without F-application on each period. For
12 weeks with F-application group, RR showed the lowest lesion depth in all
combinations.
Conclusion: The results indicated that when F
application was used, the effect of the combining a F-bonding agent and a
F-Restorative on artificial caries inhibition became more efficient with time
due to F recharge effect of certain materials.
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