In general , studies suggest that root canal sealers elicit mild to severe toxic effects and that several factors may influence biocompatibility , e.g. , material setting condition and time , material concentration , and type of exposure .
4 ) Conclusions : The available evidence shows that root canal sealers exhibit variable toxic potential at the cellular and tissue level .
However , the method ological heterogeneity among studies included in this systematic review and the somewhat conflicting results do not allow a conclusion on which type of sealer presents higher biocompatibility .
( 1 ) Aim : To perform a systematic review of the literature on the biocompatibility of  root canal sealers  that encompasses the various types of sealers that are commercially available as well as both in vitro and in vivo evidence . (
SYRCLE’s risk of bias tool for animal studies
Background Systematic Review s ( SRs ) of experimental animal studies are not yet common practice , but awareness of the merits of conducting such SRs is steadily increasing . As animal intervention studies differ from r and omized clinical trials ( RCT ) in many aspects , the methodology for SRs of clinical trials needs to be adapted and optimized for animal intervention studies . The Cochrane Collaboration developed a Risk of Bias ( RoB ) tool to establish consistency and avoid discrepancies in assessing the method ological quality of RCTs . A similar initiative is warranted in the field of animal experimentation . Methods We provide an RoB tool for animal intervention studies ( SYRCLE ’s RoB tool ) . This tool is based on the Cochrane RoB tool and has been adjusted for aspects of bias that play a specific role in animal intervention studies . To enhance transparency and applicability , we formulated signalling questions to facilitate judgment . Results The result ing RoB tool  for animal studies contains 10 entries . These entries are related to selection bias , performance bias , detection bias , attrition bias , reporting bias and other biases . Half these items are in agreement with the items in the Cochrane RoB tool . Most of the variations between the two tools are due to differences in design between RCTs and animal studies . Shortcomings in , or unfamiliarity with , specific aspects of experimental design of animal studies compared to clinical studies also play a role . Conclusions SYRCLE ’s RoB tool is an adapted version of the Cochrane RoB tool . Widespread adoption and implementation of this tool will facilitate and improve critical appraisal of evidence from animal studies . This may subsequently enhance the efficiency of translating animal research into clinical practice and increase awareness of the necessity of improving the method ological quality of animal studies
In general , studies suggest that root canal sealers elicit mild to severe toxic effects and that several factors may influence biocompatibility , e.g. , material setting condition and time , material concentration , and type of exposure .
4 ) Conclusions : The available evidence shows that root canal sealers exhibit variable toxic potential at the cellular and tissue level .
However , the method ological heterogeneity among studies included in this systematic review and the somewhat conflicting results do not allow a conclusion on which type of sealer presents higher biocompatibility .
( 1 ) Aim : To perform a systematic review of the literature on the biocompatibility of  root canal sealers  that encompasses the various types of sealers that are commercially available as well as both in vitro and in vivo evidence . (