title: Morphological and mechanical characterization of the acid-base resistant zone at the adhesive-dentin interface of intact and caries-affected dentin.
abstract: This study examined the ultrastructure of both intact and caries affected dentin-adhesive interface after artificial secondary caries formation, using scanning electron microscopy and nanoindentation testing. Half of the prepared specimens were bonded with Clearfil SE Bond (Kuraray Medical, Japan) and a resin composite (Metafil Flo, Sun Medical, Japan) for the nanoindentation test. The other specimens were stored in a buffered demineralizing solution for 90 minutes, then observed using SEM. An acid-base resistant zone (ABRZ) was observed beneath the hybrid layer, distinguished by argon-ion etching. The ABRZ of caries-affected dentin was thicker than that of normal dentin, while its nanohardess was lower than normal dentin (p<0.05). It is suggested that the monomer of Clearfil SE Bond penetrated deeper than previously reported, creating a so-called "hybrid layer." However, its physical properties depended on the condition of the dentin.
authors.affiliation: Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, Japan. inoue.ope@tmd.ac.jp
authors.forename: Go
authors.initials: G
authors.lastname: Inoue
authors.forename: Satoko
authors.initials: S
authors.lastname: Tsuchiya
authors.forename: Toru
authors.initials: T
authors.lastname: Nikaido
authors.forename: Richard M
authors.initials: RM
authors.lastname: Foxton
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D000143:Acids; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003731:Dental Caries / Q000473:pathology*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties; D017001:Tooth Demineralization / Q000473:pathology
chemical_list: D000143:Acids; C438313:Clearfil SE Bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C488280:Metafil Flo; D019279:Resin Cements