title: Microgaps and Demineralization Progress around Composite Restorations.
abstract: This study investigated the influence of adhesives and marginal sealing on demineralization progress using optical coherence tomography (OCT). Cavities (4 × 2 mm) were prepared in bovine incisors and restored using Clearfil SE Protect (SP), Bond Force (BF), Scotchbond Universal (SB), or G-Bond Plus (GB), followed by Estelite Flow Quick flowable composite. The control group received no adhesive (n = 10). After 3-d incubation in artificial saliva and 10,000 thermal cycles, gaps at enamel and dentin margins were measured at 8 locations on cross-sectional images obtained from each restoration using swept-source OCT at 1310-nm wavelength. Specimens were demineralized using acidified gel (pH = 4.5) for 5 wk and scanned every week to monitor the lesion progress at the same marginal locations. Repeated-measures analysis of variance showed that demineralization period and adhesive type and their interaction had a significant effect on the lesion size in both substrates (P < 0.001). SP, BF, and SB had significantly lower enamel and dentin initial gaps than the control and GB (P < 0.05). Enamel lesion progress was slower in the fluoride-releasing adhesives SP and BF and significantly different from SB, GB, and the control (P < 0.001). SP and BF dentin lesions were significantly different from GB and the control (P < 0.001), but not from SB (P > 0.05). A significant positive correlation (P < 0.05) was found between initial gap length and formed lesion size in both substrates, which was stronger in enamel (r = 0.63) than dentin (r = 0.35). Microgaps forming at the margins of restorations depend on adhesives and significantly contribute to the progress of demineralization around the margins, while fluoride release may decrease the rate of progression.
authors.affiliation: Operative Dentistry Division, Conservative Dental Sciences, King Abdulaziz University, Jeddah, Saudi Arabia Cariology and Operative Dentistry Department, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Turkistani
authors.affiliation: Cariology and Operative Dentistry Department, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Nakashima
authors.affiliation: Cariology and Operative Dentistry Department, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Shimada
authors.affiliation: Cariology and Operative Dentistry Department, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Tagami
authors.affiliation: Department of Restorative Dentistry, University of Washington School of Dentistry, Seattle, WA, USA arsadr@uw.edu.
authors.forename: A
authors.initials: A
authors.lastname: Sadr
mesh_terms: D000818:Animals; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods*; D003763:Dental Leakage / Q000175:diagnosis*; D018772:Dental Marginal Adaptation; D066298:In Vitro Techniques; D008689:Methacrylates; D018613:Microscopy, Confocal; D019279:Resin Cements / Q000737:chemistry*; D041623:Tomography, Optical Coherence; D017001:Tooth Demineralization / Q000139:chemically induced* / Q000175:diagnosis*
chemical_list: C000601955:Bond Force dental cement; C438313:Clearfil SE Bond; D003188:Composite Resins; C498353:G-Bond; D008689:Methacrylates; D019279:Resin Cements; C527485:estelite flow quick; C041330:Scotchbond
keywords: adhesives; composite resins; demineralization; fluoride(s); imaging; microleakage