Tooth discoloration induced by endodontic materials: a literature review

It is common knowledge that materials used in endodontics may cause discoloration and thus impair the aesthetic outcome of the treated tooth. The purpose of this review is to summarise the existing knowledge on the discoloration potential of materials used for endodontic procedures. A comprehensive literature search covering the period from 1966 to 2011 was conducted on Pubmed and the Cochrane Library using different keyword combinations including 'tooth', 'colour', 'discoloration', 'staining', 'endodontic''root canal''sealer', 'dressing', 'medicament', 'obturation', 'filling', 'treatment', 'portland cement', 'MTA' and 'antibiotic paste'. Any relevant work published in the English language in peer-reviewed journals and presenting pertinent information related to the purpose of this overview was considered for inclusion. In addition, bibliographies of all relevant papers and previous review articles were hand searched and the reference lists from endodontic textbooks were also reviewed. Articles were excluded if an English abstract was unavailable, if only single clinical reports or conference reports were included, or if the topic was unrelated to the subject. Ten in-vitro studies, one randomized controlled trial and one multicenter randomized controlled trial met the inclusion criteria. There were not any recently used endodontic materials that would not induce at least measurable colour changes. For a wide range of materials currently available on the market there is only scarce or no evidence available on their staining ability. Endodontic therapy should not focus solely on biological and functional aspects, but take aesthetic considerations into account as well. To reduce the risk of material-induced tooth discoloration all materials should be applied carefully in areas of aesthetic concern. The need for further research in this field and for the development of non-staining endodontic materials is evident.