title: Formation of a hard tissue barrier after pulp cappings in humans. A systematic review.
abstract: OBJECTIVE
  To evaluate the evidence on the formation of a hard tissue barrier after pulp capping in humans.
  
  
  METHODS
  A PubMed and CENTRAL literature search with specific indexing terms and a hand search were made. The authors assessed the level of evidence of each publication as high, moderate or low. Based on this, the evidence grade of the conclusions was rated as strong, moderately strong, limited or insufficient.
  
  
  RESULTS
  The initial search process resulted in a total of 171 publications. After reading the abstracts and hand searching the reference lists of the retrieved publications, 107 studies were retrieved in full-text and interpreted. After the interpretation, 21 studies remained and were included in the systematic review and given a level of evidence. No study had a high level of evidence, one study had moderate and 20 studies had a low level of evidence. There was heterogeneity between the studies; therefore, no meta-analysis was performed. The majority of studies on pulp capping using calcium hydroxide based materials reported formation of hard tissue bridging, studies on other pulp capping materials such as bonding agents presented inferior results. The evidence grade was insufficient.
  
  
  CONCLUSIONS
  Insufficient evidence grade does not necessarily imply that there is no effect of a pulp capping procedure or that it should not be used. Rather, the insufficient evidence underpins the need for high-quality studies.
authors: Department of Endodontics, Faculty of Odontology, Malmo University, Malmo, Sweden. helena.olsson@od.mah.se
authors: H
authors: H
authors: Olsson
authors: K
authors: K
authors: Petersson
authors: M
authors: M
authors: Rohlin