Effect of LED light-curing time for the adhesive resin on the modulus of elasticity.
OBJECTIVE
To evaluate the elastic modulus of successive layers where an adhesive resin was cured by different light-curing times.


METHODS
Eighty dentin discs which were 2 mm thick were prepared from 40 sound third molars. The dentin discs were further divided into four groups and bonded with 3M Single Bond 2 and cured with an LED for 5, 10, 15 and 20s. Bonded specimens were restored with a microhybrid resin composite. Specimens were cut perpendicular to the resin dentin interface, embedded in epoxy resin, and polished. Polished specimens were evaluated for the elastic modulus at the layer of dentin, hybrid layer, adhesive resin, and resin composite at 24 hours after preparation.


RESULTS
Light-curing times influenced the elastic modulus of hybrid layer and adhesive resin. The significant differences of elastic modulus among successive layers were found. The results suggested that extension of light-curing times of adhesive resin from 5 to 20 seconds increased the mechanical properties of the resin dentin interface.
Senawongse
Pisol
P
Department of Operative Dentistry, Faculty of Dentistry, Mahidol University, 6 Yothi Street, Phayathai, Bangkok, 10400, Thailand. dtpse@mahidol.ac.th
Harnirattisai
Choltacha
C
Otsuki
Masayuki
M
Tagami
Junji
J
D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry / Q000528:radiation effects*; D016001:Confidence Intervals; D017220:Dentin-Bonding Agents / Q000737:chemistry / Q000528:radiation effects*; D004548:Elasticity / Q000528:radiation effects; D006801:Humans; D013997:Time Factors
D017220:Dentin-Bonding Agents; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate