Effect of two-step adhesive systems on inhibition of secondary caries around fluoride-releasing resin composite restorations in root dentine.
OBJECTIVE
The purpose of this study was to investigate the effect of two-step adhesive systems on secondary caries inhibition around fluoride-releasing materials in vitro.


METHODS
Two self-etching primer systems, Clearfil SE Bond (SE) and UniFil Bond (UB), and two one-bottle systems with a total-etch wet-bonding technique, Single Bond (SB) and One-Step (OS), were used prior to placement of resin composites either with (Reactmer) or without (Z100) fluoride release. Class V cavities prepared in extracted human premolars were restored with various combinations of materials: Reactmer/SE, Reactmer/UB, Reactmer/SB, Reactmer/OS, Z100/SE, Z100/UB, Z100/SB and Z100/OS. After storage for 14 days, the restored teeth were incubated in bacterial medium containing sucrose with Streptoccus mutans for 2 weeks. Water sorption and desorption of the adhesives and fluoride release from the resins either coated with adhesive or uncoated were also determined.


RESULTS
The one-bottle groups showed higher water sorption and desorption than the self-etching primer groups. Although fluoride release from the Reactmer specimens was suppressed by the adhesive coating, the one-bottle groups allowed significantly higher fluoride release than the self-etching primer groups. On microradiographs, the radio-opaque layers adjacent to the Reactmer restorations were thick and clear, while the layers adjacent to the Z100 restorations were thin and unclear. For the Reactmer restorations, the radio-opaque layers associated with the one-bottle groups were significantly thicker than for the self-etching primer groups.


CONCLUSIONS
These results indicated that the use of one-bottle wet-bonding systems for bonding of fluoride-releasing resin composites to dentine may contribute to inhibit secondary caries compared to self-etching primer systems.
Itota
Toshiyuki
T
Department of Operative Dentistry, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama 700-8525, Japan. itota@md.okayama-u.ac.jp
Nakabo
Satoshi
S
Narukami
Tomoko
T
Tashiro
Yoko
Y
Torii
Yasuhiro
Y
McCabe
John F
JF
Yoshiyama
Masahiro
M
D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002327:Cariostatic Agents / Q000008:administration & dosage* / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods*; D003731:Dental Caries / Q000382:microbiology / Q000517:prevention & control*; D003737:Dental Cavity Preparation / Q000145:classification; D003793:Dental Restoration, Permanent / Q000379:methods*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005459:Fluorides / Q000008:administration & dosage* / Q000737:chemistry; D006801:Humans; D008689:Methacrylates / Q000737:chemistry; D008852:Microradiography; D019279:Resin Cements / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013295:Streptococcus mutans / Q000502:physiology; D014092:Tooth Root / Q000648:ultrastructure*; D014867:Water / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; D002327:Cariostatic Agents; C438313:Clearfil SE Bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; C407402:Unifil Bond; C083568:Z100 composite resin; C465006:reactmer paste; C115612:single bond; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate; D012822:Silicon Dioxide; D015040:Zirconium; D005459:Fluorides