Dentinal Pre-Treatment in Restorative Dentistry.

ABSTRACT

The advances in adhesive techniques for bonding dental cements to teeth have long been advantageous in dentistry. Adhesive systems offer retaining areas that permit dental restorations to be placed. Bonding to tooth includes bonding to both enamel and underlying dentin. Adhesion to dentin is the main concern as most of damaged teeth have significant amount of misplaced enamel and require good adhesion to dentin. However, dentin exhibits complex structure which makes it difficult to bond with various materials. Hence to enhance bonding between dentin/tooth and adhesive material, it vital to pre-treat dentin with different gents. Various agents are used to treat dentin before restoration is placed. The agents used are chlorhexidine, sodium hypochlorite, benzalkonium chloride, iodine-based disinfectants, ozone, lasers, glutaraldehyde and proanthocyanidins, added hydrophobic resin layer application, ethanol, biomimetic, remineralizing agents, ethylene diamine tetra acetic acid, polyacrylic acid. 2% Chlorhexidine digluconate wash has been shown to successfully conserve the bond strength, when etch-and-rinse adhesive systems were used for up to 6 months. This can be due to inhibitory ability of CHX to the matrix metalloproteinases (MMPs) found in etched dentin. Dentinal pre-treatment is also done to eliminate bacteria remaining in cavity wall. 2.5% NaOCl pretreatment decreased the shear bond strength (SBS) of self-etch adhesive system and suggested NaOCl disinfectant to be used with etch-and-rinse bonding systems. The residual bacteria left behind after restorative procedure may endure and multiply which may lead to pulpal irritation, threat of recurrent caries and / or postoperative sensitivity, and therefore leads to failure of the dental restoration. The occurrence of secondary caries is the most common reason for the restorations failures.Attention to the antimicrobial agents and their effects on the pulp began in the early 1970s by Brännström and Nyborg, who focused on the significance of eliminating residual bacteria remaining on cavity walls.Use of 5.25% NaOCl solution for 15 seconds to eradicate “Staphylococcus aureus, Candida albicans, Porphyromonas gingivalis, and Prevotella intermedia, Porphyromonas endodontalis. Iodine based compounds have capacity to destroy the bacterial cell by affecting its proteins, nucleotides, and fatty acids. EDTA composition are highly successful in eliminate existing biofilms. It prevents biofilm formation by decreasing the adhesion of bacteria.This article reviews various agents, their mechanisms of action on dentin, effect on bond strength, their antibacterial activity, effect of agents on pulp, and comparative studies of these pretreatments. Several available agents have various advantages and disadvantages. Therefore, it is necessary to select appropriate agent for better bonding.