Smear layer: a brief review of general concepts. Part I. Characteristics, compounds, structure, bacteria and sealing

Abstract

Smear layer interference on endodontic therapy success is not completely clear. The wide and controversial literature about this issue has motivated this present review. The first part of this study purposed to briefly review general concepts concerning the smear layer: its structure and composition, the relation between bacteria and smear layer, effects of smear layer on penetration of sealer into dentinal tubules and the microleakage of root canal fillings with and without smear layer. Although smear layer construction during canal prepare is proved, the advantages and disadvantages of smear layer presence, and whether it should be removed or not from root canals, are still a question in endodontics. Key words: smear layer, sealing, bacteria, microleakage, and structure.