Removal strategies for carious tissues in deep lesions

Abstract

It used to be considered preferable to remove all carious tissues with any signs of disease, regardless of the consequences, even at the expense of the hard tissue, causing stress to, or exposing, the dental pulp. However, it is now understood that this is not only unnecessary but also undesirable. Bacteria can be sealed under restorations, depriving them of nutrition and inactivating them. In asymptomatic, vital teeth with deep lesions, strategies for conservative carious tissue removal which reduce tissue loss and pulp exposure risk have to be balanced against removing adequate tissue to maximize restoration longevity. The criterion used to guide carious dentin tissue removal is hardness, judged by tactile feedback during examination. The levels are described as: Hard, Firm, Leathery, and Soft Dentin. The four main strategies for carious tissue removal are: Non-selective Removal to Hard Dentin (now considered to be overtreatment and too destructive and not recommended); Selective Removal to Firm Dentin; Selective Removal to Soft Dentin; and Stepwise Removal. Other strategies for managing deep carious lesions are: Non-Restorative Cavity Control where lesions are made cleansable, and Sealing-In strategies (including Fissure Sealing in permanent and primary teeth and sealing using a preformed crown in primary teeth). These strategies for managing carious tissues result in a change in the biofilm (reduced bacterial diversity, numbers, and cariogenic potential). The guiding principles behind removal and sealing are underpinned by a desire to preserve tissue, avoid pulp exposure, and maximize tooth longevity.