An in vitro investigation of microtensile bond strengths of two dentine adhesives to caries-affected dentine.
OBJECTIVE
To compare the micro-tensile bond strengths of two different adhesive systems (ABF (Clearfil Protect Bond), Kuraray Medical Inc., Tokyo, Japan) and Prime & Bond NT (PBNT, Dentsply, Konstanz, Germany) bonded to caries-affected dentine retained after chemo-mechanical caries removal using Carisolv gel, with that retained after excavation using conventional hand instrumentation.


METHODS
Twenty, adult, human extracted carious teeth were used in this split tooth study with bur-cut cavities in sound dentine acting as controls. After clinical caries excavation, the occlusal cavities in each experimental group were restored with either bonding system plus composite. Matchstick-shaped samples through the bond interfaces were sectioned and microtensile bond strengths recorded. Scanning electron microscopy (SEM) was used to ascertain the mode of failure at the restoration-dentine interface.


RESULTS
Statistical analysis of the bond strength data showed that for the ABF group, there was no difference in bond strengths between the controls and Carisolv group but these values were significantly higher than those for the hand-excavated samples. PBNT samples showed no significant differences in any of the three test groups, with wider ranging data sets. SEM analysis indicated a variety of failures at the interface including cohesive failures within the caries-affected dentine itself.


CONCLUSIONS
From the data generated by this study it could be concluded that microtensile bond strengths of PBNT/composite restorations to caries-affected dentine in clinical cavities were statistically comparable to those to sound dentine. In the ABF/composite restored group (self-etched), the use of conventional hand excavation appeared to weaken the bond strength to the remaining caries-affected dentine. However, the use of Carisolv gel excavation did not compromise bond strengths to caries-affected dentine in either group tested.
Sonoda
H
H
Tokyo Medical and Dental University, 3-21 Kanda Srugadai 2-Chome, Chiyoda-ku, Tokyo 101-0062, Japan.
Banerjee
A
A
Sherriff
M
M
Tagami
J
J
Watson
T F
TF
D000268:Adhesiveness; D000328:Adult; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003731:Dental Caries / Q000473:pathology*; D003737:Dental Cavity Preparation / Q000295:instrumentation / Q000379:methods; D003793:Dental Restoration, Permanent / Q000379:methods; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D018698:Glutamic Acid / Q000627:therapeutic use; D006801:Humans; D007930:Leucine / Q000627:therapeutic use; D008239:Lysine / Q000627:therapeutic use; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D011109:Polymethacrylic Acids / Q000737:chemistry; D013499:Surface Properties; D013718:Tensile Strength
C119934:Carisolv; C112274:Clearfil Liner Bond 2; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C466112:Esthet-X; D008689:Methacrylates; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; D018698:Glutamic Acid; D007930:Leucine; D008239:Lysine