Effect of 2% Chlorhexidine Digluconate on the Bond Strength to Normal Versus Caries-affected Dentin

Abstract

SUMMARY This study evaluated the effect of 2% chlorhexidine digluconate (CHX) used as a therapeutic primer on the long-term bond strengths of two etch-and-rinse adhesives to normal (ND) and caries-affected (CAD) dentin. Forty extracted human molars with coronal carious lesions, surrounded by normal dentin, were selected for this study. Flat surfaces of two types of dentin (i.e. ND and CAD) were prepared with a water-cooled high speed diamond disc, and then acid-etched, rinsed and air-dried. In control groups, dentin was re-hydrated with distilled water, blot-dried and bonded with a three-step (Scotchbond Multi-Purpose-MP) or a two-step (Single Bond 2-SB) etch-and-rinse adhesive. In experimental groups, dentin was re-hydrated with 2% CHX (60 s), blot-dried and bonded with the same adhesives. Resin composite build-ups were made. Specimens were prepared for microtensile bond testing in accordance with the non-trimming technique and then tested either immediately or after 6-month storage in artificial saliva. Data were analyzed by ANOVA/Bonferroni tests (α = 0.05). CHX did not affect the immediate bond strength to ND or CAD (p>0.05). CHX treatment significantly lowered the loss of bond strength after 6 months seen in control bonds for ND (p<0.05), but it did not alter the bond strength of CAD (p>0.05). Application of MP on CHX-treated ND or CAD produced bonds that did not change over 6 months of storage.

Chlorhexidine does not increase immediate bond strength of etch-and-rinse adhesive to caries-affected dentin of primary and permanent teeth

“…In addition to minimizing the degradation of resin-dentin bonds, CHX application should not negatively influence the immediate bond strength, which has already been pointed out in literature (13,17). However, it is unclear in the literature the effect of CHX in caries-affected dentin (18)(19)(20), especially in primary teeth.…”

Influence of chlorhexidine application on longitudinal adhesive bond strength in deciduous teeth

“…This process exposes a dense layer of fibrils of the organic matrix 8,9 composed primarily of type I collagen and proteoglycan, 12,13 which must be completely infiltrated with the adhesive resin to form the hybrid layer. 12,16 However, a decrease in the diffusion gradient of the resin monomers results in a layer of denuded collagen at the base of the hybrid layer.…”

“…Studies evaluating the effect of chlorhexidine after acid etching used an application time of 60 seconds. [7][8][9][10][11] In a few studies, researchers attempted to reduce this time to save both the professional's and the patient's time. 10,[12][13][14] However, none of these studies evaluated the reduced time of chlorhexidine application on the dentin of deciduous teeth.…”

Bonding efficiency and durability: current possibilities

“…88 Even though the presence of carious-affected dentin, as well as artificially eroded dentin, relates to inferior bond strength values, 53,94,95 CHX can preserve adhesive interface stablished by two-step etch-and-rinse adhesives, although not indefinitely. 77,96,97,98,99 Higher bond strength durability of a two-step self-etch adhesive over 2-year aging in artificial saliva and under simulated intrapulpal pressure was also described in the literature when caries-affected dentin was pretreated with CHX. 100 Besides, the degradation of the adhesive interface in primary teeth may be counteracted or blocked by the application of CHX as a therapeutic primer.…”