In Vitro Evaluation of Benzalkonium Chloride in the Preservation of Adhesive Interfaces

Abstract

Benzalkonium chloride preserves resin-dentin bonds by reducing collagen solubilization. When incorporated into adhesive blends, benzalkonium chloride provides comparable bond stability to other inhibitors and application protocols without adding more steps to the bonding sequence. SUMMARYInhibition of endogenous dentin matrix metalloproteinases (MMPs) by benzalkonium chloride (BAC) decreases collagen solubilization and may help improve resin-dentin bond stability. Objective: This study evaluated the resin-dentin bond stability of experimental adhesive blends containing BAC and the stability of dentin matrices by assessing the mass loss and collagen solubilization from dentin beams pretreated with BAC.Materials and Methods: Twenty-five healthy molars were used for the bond strength evaluation of a two-step etch-and-rinse adhesive (Adper Single Bond Plus, SB) modified with BAC or not. The following groups were tested: 1) SB with no inhibitor (control); 2) topical 2.0% chlorhexidine + SB; 3) 1.0% BAC etchant + SB; 4) 0.5% BAC-SB; and 5) 1.0% BAC-SB. Microtensile bond strength (lTBS) and failure mode distribution under standard error of the mean were evaluated after 24 hours and six months of storage in artificial saliva (AS). A two-way analysis of variance and Tukey test with a significance level of p,0.05 was used for data analysis. In addition, 30 completely demineralized dentin beams from human molars were either dipped in deionized water (DW, control) or dipped in 0.5% and 1.0% BAC for 60 seconds, and then incubated in AS. Collagen solubilization was assessed by evaluating the dry mass loss and quantifying the amount of hydroxyproline (HYP) released from hydrolyzed specimens after four weeks of incubation.Results: The control group demonstrated lower lTBS than some of the experimental groups containing BAC at 24 hours and six months (p,0.05). When BAC was incorporated into the adhesive blend in concentrations of 0.5% and *Camila Sabatini, DDS, MS, assistant professor,

Preservation of resin–dentin interfaces treated with benzalkonium chloride adhesive blends

“…No differences in mass loss or HYP release were found when the beams were pretreated with 0.5% or 1.0% BAC, but both demonstrated less mass loss and HYP release than the control beams. These findings confirm those from our previous study and from other studies, which have also reported BAC to be an effective inhibitor of MMP activity .…”

Dentin Bonding: Can We Make it Last?

“…Commercially available BAC-containing etchants can be used without affecting immediate bond strength to enamel or dentin. 96 BAC also inhibits dentinal MMPs [97][98][99] and may also improve the durability of dentin bonding when incorporated either into the etchant or the adhesive. 99 Tetracyclines and their antimicrobially inactive analogs inhibit MMP with their cationic chelating properties and have been shown to inhibit salivary and dentinal MMPs as well.…”

Bonding efficiency and durability: current possibilities

“…74,118,119 In this sense, a growing predisposition among clinicians in properly applying 0.2-2% CHX for 15-60 s for re-wetting the collagen network on acid-etched dentin 77,79,89,120 to minimize degradation of resin-dentin bonds, can be currently appreciated. 115,119 Tough medium-term randomized clinical trials (18-36 months) does not show significant beneficial results from incorporating CHX to adhesive treatment of dentin. 121,122,123 Loguercio et al, 105 incite researchers to evaluate the only one proven clinically and easy to adopt strategy 88 after long-term follow-ups, when the benefits of CHX would possibly turn out to be detectable.…”

“…106 After oversaturating proteases binding sites, if still available (higher concentrations), it can remain bound to collagen fibrils for later release. 115 Adversely, a limitation of CHX indication as an enzymatic inhibitor is that its effect seems not to be indefinitely long. 85 Because CHX molecule is large and water soluble, it may be gradually leached out from the adhesive interface, 92 especially when in contact with an external environment (through marginal gaps, for instance).…”