17 Bond Strength of HEMA-free And HEMA-containing Adhesives Under Pulpal Pressure

Wednesday, March 21, 2012: 2:30 p.m. - 4 p.m.
Presentation Type: Oral Session
M.H.A. MAHDAN1, M. NAKAJIMA1, and J. TAGAMI2, 1Cariology and Operative Dentistry, Tokyo Medical & Dental University, Tokyo, Japan, 2Cariology and Operative Dentistry, Global COE Program, Tokyo Medical & Dental University, Tokyo, Japan

Objectives: To evaluate the effect of simulated pulpal pressure (PP) on initial bond strength of one-stsep self-etch adhesives with different smear layer preparation. Methods: Flat coronal dentin surfaces were obtained from extracted molar teeth .Smear layers were created by grinding with either #180 or #600 grit paper. A HEMA-free one-step self-etch adhesive, Xeno V (XV; Denstply,Germany) and a HEMA-containing adhesive, Tokuyama Bond Force (TBF;Tokuyama Corporation,Japan) were applied to the dentin surfaces according to the manufacturer's instructions under a hydrostatic pressure of 0 or 15 cmH2O. Specimens bonded under 0 cmH20 pressure was served as a control group.  After coronal build up with composite resin (CLEARFIL AP-X), the specimens were stored in water at 370C for 24 hour. Bond strength to dentin were determined using microtensile bond (µTBS) testing and all data were statistically analyzed using one-way ANOVA (materials and experimental conditions) and additional t-test. Results: The bond strength values (µTBS) results table are as follows.

MATERIALS

EXPERIMENTAL CONDITION

SiC PAPERS (grit size)

PULPAL PRESSURE

0 cm H20

15cm H20

TOKUYAMA BOND FORCE

#180

33.4±9.7Ab

31.2±8.8 Ab

#600

39.6+8.3Ab

33.3_6.8Ab

XENO V

#180

29.7±6.8Ab

21.6±8.9Bc

# 600

    39.0±9.5Ac

    34.2±10.5Ad

Values are in MPaħS.D. n=8 (per group).  Groups identified by the same capital and small superscript letter in each row and column are not significantly different (p>0.05). 

Conclusions:  .

The 15 cmH20 pulpal pressure (PP) had decreased the bond strength (BS) significantly of the HEMA-free material, XV in  the  thicker smear layer (#180-grit prepared).


Keywords: Dental materials, Dentin, Dentin bonding agents and Pulpal Pressure
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