Rationale behind the design and comparative evaluation of an all-in-one self-etch model adhesive.
OBJECTIVE
To investigate and compare bonding and dentin sealing efficacy of a marketed all-in-one and an experimental model adhesive with minimum effective amounts of acidic monomer and water.


METHODS
Composition of model adhesive (NAD) in mass%: UDMA (45), 4-META (20), H2O (7.5), and acetone (27.5). For characterization of a reasonable NAD application procedure shear bond strengths (SBS, n=8) were determined on human enamel and dentin. Clearfil S3 Bond (TSB; Kuraray) served as reference. SBSs were evaluated after 10 min, 1 and 7 days, and 1 month, marginal adaptation (n=8) was assessed in cylindrical butt-joint dentin cavities. Diffusive and convective water fluxes through 1mm thick adhesive-coated dentin disks (n=6) were qualitatively and quantitatively analyzed.


RESULTS
SBSs proved that application of NAD in one coat with 20s agitated dwell time was > or =20 MPa, enamel SBSs (24h) were 25 MPa, p>0.05. Dentin SBSs for TSB and NAD were not different (p>0.05) at the four stages (means: 18.9, 23.5, 25.4, and 23.6 MPa). Five and seven of the eight bonded restorations with TSB and NAD were gap-free (p>0.05). Dentin disks treated with EDTA from both sides or one side only were highly permeable for liquid, whereas adhesive-coated dentin disks showed no permeability at 0 and 2.5 kPa water pressure.


CONCLUSIONS
Within the limitations of this study the model adhesive tested represents a promising basic composition for all-in-one adhesives, eliminating common problems encountered with single step adhesives such as phase separation and permeability.
Kanehira
Masafumi
M
Graduate School of Dentistry, Department of Restorative Dentistry, Division of Operative Dentistry, Tohoku University, Sendai, Japan.
Finger
Werner J
WJ
Ishihata
Hiroshi
H
Hoffmann
Marcus
M
Manabe
Atsufumi
A
Shimauchi
Hidetoshi
H
Komatsu
Masashi
M
D000096:Acetone / Q000737:chemistry; D000293:Adolescent; D000328:Adult; D002614:Chelating Agents / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure; D018772:Dental Marginal Adaptation; D003804:Dentin / Q000648:ultrastructure; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D004492:Edetic Acid / Q000737:chemistry; D005260:Female; D006801:Humans; D006874:Hydrostatic Pressure; D049408:Luminescent Agents; D008165:Luminol; D008297:Male; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D012997:Solvents / Q000737:chemistry; D013314:Stress, Mechanical; D013997:Time Factors; D014867:Water / Q000737:chemistry; D055815:Young Adult
D002614:Chelating Agents; C505694:Clearfil S3 Bond; D017220:Dentin-Bonding Agents; D049408:Luminescent Agents; D008689:Methacrylates; D011140:Polyurethanes; D019279:Resin Cements; D012997:Solvents; D014867:Water; C029824:urethane dimethacrylate luting resin; D000096:Acetone; D008165:Luminol; C034139:4-methacryloxyethyltrimellitic acid anhydride; D004492:Edetic Acid