All-in-one self-etch model adhesives: HEMA-free and without phase separation.
OBJECTIVE
Aim of this study was to design HEMA-free all-in-one self-etch model adhesives without phase separation, and to investigate their efficiency on extracted human teeth.


METHODS
Compositions of adhesives in mass% (1): UDMA (25), 4-META (20), H(2)O (0, 1, 2, 5, 10, 20, 35, and 45), balance of acetone or ethanol. (2): UDMA (35), 4-META or 4-MET (28), H(2)O (0, 2, 4, 5, 6, and 8), balance of acetone. Phase separation was evaluated on samples exposed to ambient atmosphere. Conventional shear bond strengths (SBS, n=8) were determined on human enamel and dentin. Marginal adaptation (MGW, n=8) was assessed in cylindrical butt-joint dentin cavities.


RESULTS
Solutions (1) and (2) with 5 and 8% or less water content, respectively, showed no phase separation. SBSs on enamel were not different within the acetone- or ethanol-group and between the adhesive groups (1). Water content of adhesives (2) was a significant determinant of enamel SBSs, groups with 4-META or 4-MET were not different (p>0.05). Dentin SBSs with adhesives (1) were not different (p>0.05) within solvent groups, yet higher for acetone-dissolved adhesives (p<0.05). Dentin SBSs with adhesives (2) were different by water content and functional monomer (p<0.05). MGW for solutions (1) were smaller with acetone-dissolved than with ethanol-dissolved adhesives (p<0.001). Acetone solutions between 2 and 45% water content produced almost perfect marginal adaptation. Marginal adaptation of adhesives (2) was almost perfect at 5 through 8% water content.


CONCLUSIONS
Simplified HEMA-free self-etch adhesives without phase separation were prepared without compromises on bonding efficiency to enamel and dentin.
Furukawa
Masae
M
Department of Clinical Cariology and Endodontology, Showa University, Tokyo, Japan.
Shigetani
Yoshimi
Y
Finger
Werner J
WJ
Hoffmann
Marcus
M
Kanehira
Masafumi
M
Endo
Tatsuo
T
Komatsu
Masashi
M
D000096:Acetone; D001840:Dental Bonding; D003743:Dental Enamel; D045662:Dental Etching / Q000379:methods; D018772:Dental Marginal Adaptation; D003799:Dental Stress Analysis; D003804:Dentin; D000431:Ethanol; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates; D044367:Phase Transition; D011140:Polyurethanes; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D014867:Water
D008689:Methacrylates; D011140:Polyurethanes; D019279:Resin Cements; D014867:Water; C029824:urethane dimethacrylate luting resin; D000096:Acetone; D000431:Ethanol; C005044:hydroxyethyl methacrylate; C034139:4-methacryloxyethyltrimellitic acid anhydride