Bonding efficacy and interfacial microstructure between resin and dentine primed with glyceryl methacrylate.
OBJECTIVE
To evaluate the effect of two experimental primers based on glyceryl methacrylate (GM, 2,3-dihydroxypropyl methacrylate) and 2-hydroxyethyl methacrylate (2-HEMA) on the marginal adaptation of light-cured composite placed into cylindrical dentine cavities and to study the interfacial microstructure.


METHODS
The bonding efficacy of two experimental dentine primers combined with a dentine cleanser composed of either 0.5 mol l-1 EDTA neutralized to pH 7.4 by sodium hydroxide or 10% citric acid containing 3% ferric chloride (10-3 solution), and a commercial dentine bonding agent containing phosphate ester, were examined by measuring the wall-to-wall polymerization contraction gap of a commercial light-activated resin composite placed into cylindrical dentine cavities. The adhesive interface between the dentine and the dentine adhesive was observed using a transmission electron microscope (TEM).


RESULTS
The formation of a contraction gap was completely prevented by priming with GM, regardless of the dentine cleanser used. However, in groups primed with 2-HEMA, gap formation was observed in three and four specimens out of 10 in the groups that were cleaned with the EDTA and 10-3 solution, respectively. In samples primed with GM, a high-density layer was observed by TEM at the superficial dentine in the hybrid layer, which may have indicated a high monomer content, whereas no density variations were observed in the hybrid layer in samples primed with 2-HEMA.
Chigira
H
H
Department of Operative Dentistry, Showa University School of Dentistry, Tokyo, Japan.
Itoh
K
K
Tachikawa
T
T
Wakumoto
S
S
Hisamitsu
H
H
D000269:Adhesives / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002712:Chlorides; D019343:Citric Acid / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D018772:Dental Marginal Adaptation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D004492:Edetic Acid / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D005989:Glycerides / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D008768:Methylmethacrylates / Q000737:chemistry; D008854:Microscopy, Electron; D010710:Phosphates / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry; D013499:Surface Properties
C102901:2,3-dihydroxypropylmethacrylate; D000269:Adhesives; D002712:Chlorides; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D005290:Ferric Compounds; D005989:Glycerides; D008689:Methacrylates; D008768:Methylmethacrylates; D010710:Phosphates; D019279:Resin Cements; C074669:Clearfil Photo Bond; D019343:Citric Acid; D012972:Sodium Hydroxide; C069750:glyceryl methacrylate; C005044:hydroxyethyl methacrylate; D004492:Edetic Acid; C024555:ferric chloride