Priming dentin with glutaraldehyde affects resin-dentin bond strength

Objectives: This work tested the following null hypotheses: 1) there is no difference in resin-dentin bond strength (RDBS) when a glutaraldehyde primer solution is added to bonding procedures, and 2) there is no difference in RDBS when the same experimental adhesive systems are applied in dry or wet demineralized dentin conditions.

Methods: Human, extracted upper third molars were selected. Flat, mid-coronal dentin was exposed for bonding and four groups of six teeth were formed. Two groups were designated for dry dentin technique and two for the wet one: DRY: 1) Group GD: acid etching + glutaraldehyde primer (primer A) + HEMA/ethanol primer (primer B) -under dried dentin + unfilled resin; 2) Group D: the same as GD, excepting primer A application; WET: 3) Group GW: the same as GD, but application of primer B was conducted over wet dentin condition; 4) Group W: the same as GW, excepting primer A application. The bonding resin was photo-polymerized and a resin core build-up was fabricated over the adhesive layer. Teeth were then prepared for microtensile bond test for RDBS evaluation. The obtained data were submitted to ANOVA and Tukey tests (a=0.05).

Results: RDBS (MPa): GD=58.0(26.9); GW=56.8(23.6); D=47.1(19.3); W=42.1(17.6). Glutaraldehyde primer application significantly improved RDBS (p<0.05). No significant difference was observed when the same experimental adhesive system was applied whether in dry or wet dentin conditions (p=0.38).

Conclusion: Glutaraldehyde was effective to enhance RDBS in dry or wet dentin substrates. Such results permit to reject the first null hypothesis and accept the second one.

Supported by CAPES and Bauru Dental School-Brazil