Dentin and pulp reactions to caries and operative treatment: biological variables affecting treatment outcome

An important issue prior to restorative or endodontic treatment of carious teeth is the assessment of the different conditions of each individual case. This relates to the static, anatomical considerations of the location of the caries lesion, as well as the dynamic activity and extent of the carious process. Moreover, the restorative treatment may be carried out for prosthetic or cosmetic purposes and this may involve the cutting of sound and unaffected dentin. These aspects are more or less outlined in old textbooks going back to the principles described by Black (1). However, each factor and its relative importance have changed over the years. The major focus has been on improving the technical aspects of cavity design and the choice of restorative material, as well as examining the clinical procedures involved. Less attention has been paid to the pathology of caries in relation to restorative treatment and the different types of lesion progression. Rapidly progressing lesions and slowly progressing lesions have seldom been related to different treatment strategies or guidelines in relation to excavation (2). In addition, the absence of a diagnostic device for estimating the degree and severity of pulp inflammation might also explain why an overall consensus is still lacking in relation to the operative or endodontic treatment of deep carious lesions. The deep lesion approach may be quite radical and invasive, and leaving intentionally carious tissue behind has not been recommended (3), but conservative procedures have also been advocated, such as the indirect pulp capping