Critical appraisal: bulk-fill flowable composite resins.

Recent developed flowable composite resins have been marketed for bulk filling of preparations or replacement of dentin in a single increment. The obvious attraction of these materials-quicker placement of restorations-has rapidly made them very popular despite the limited in vitro data and lack of clinical studies. This Critical Appraisal will review some of the available in vitro literature on the topic and summarize the available knowledge in this new category of restorative materials.