title: Effect of light-curing method and irradiation time on marginal sealing and cavity wall adaptation of resin composite restorations.
abstract: OBJECTIVE
  To evaluate the effect of irradiation time on two light-curing methods on the marginal sealing and cavity wall adaptation of resin-based composite restorations.
  
  
  METHODS
  Cylindrical cavities, 1 mm deep and 3 mm in diameter (C-factor = 2.3) were prepared on flat superficial bovine dentin surfaces. The teeth were restored with Clearfil Photo Bond, Clearfil Liner Bond 2 or Super-Bond D-Liner adhesive systems followed by Photo Clearfil Bright resin-based composite. The resins were cured using a conventional method at an output of 600 mW/cm2 for 60 s, or 600 mW/cm2 for 30 s, or the slow-start curing method at an output of 270 mW/cm2 for 10 s + 5 s (interval) + 600 mW/cm2 for 50 s or 270 mW/cm2 for 10 s + 5 s (interval) + 600 mW/cm2 for 20 s. After thermocycling, a dye penetration test was carried out. The dye penetration length was calculated as a percentage of the total cavity wall length.
  
  
  RESULTS
  Slow-start curing method; 270 mW/cm2 10 s + 5 s (interval) + 600 mW/cm2 for 50 s showed the best marginal sealing and cavity wall adaptation. A shorter irradiation time increased cavity wall adaptation when the conventional curing method was used. Super-Bond D-Liner showed good marginal sealing and resin composite adaptation to the cavity wall regardless of the light-curing method.
authors.affiliation: Dept. of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, Yushima, Tokyo, Japan. yoshikawa.ope@tmd.ac.jp
authors.forename: Takako
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Nakaoki
authors.forename: Tsunehiko
authors.initials: T
authors.lastname: Takada
authors.forename: Michael F
authors.initials: MF
authors.lastname: Burrow
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D000818:Animals; D002417:Cattle; D004396:Coloring Agents; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D001840:Dental Bonding; D003736:Dental Cavity Lining; D003737:Dental Cavity Preparation / Q000145:classification; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D008027:Light; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D011829:Radiation Dosage; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors
chemical_list: C112274:Clearfil Liner Bond 2; D004396:Coloring Agents; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; C084543:Super Bond D-Liner; C074669:Clearfil Photo Bond; C091838:Clearfil Photo Anterior