(PR72) The Effectiveness of Orifice Barriers in Preventing Coronal Microleakage in Endodontically Treated Teeth: A Systematic Review

The importance of an adequate coronal restoration and seal on the outcome of endodontic treatment has been well-established. The placement of a coronal orifice barrier immediately following obturation can help to ensure the root canal system does not become contaminated if the temporary or permanent restoration fails by providing a seal over exposed gutta-percha. The aim of this study was to evaluate the effectiveness of orifice barriers in preventing coronal microleakage and to determine which material is the most effective. Medline (PubMed), Web of Science, Embase, and the grey literature were searched up to April 2022. Study selection and data extraction were performed in duplicate, and eligible studies were critically appraised for risk of bias and quality of evidence. 12 studies were included in the review. All studies found greater microleakage in the positive control groups (which did not receive orifice barriers) compared to the experimental groups. MTA, glass ionomer, CEM cement, Cavit, and composite were all found to be effective orifice barrier materials. Due to differences in methodologies and materials tested, no material was found to be the most effective. Nine studies were found to have a high risk of bias, and three studies were found to have a moderate risk of bias. A low quality of evidence suggests that orifice barriers are effective in preventing coronal microleakage in the laboratory setting, though there is little evidence to support one material as the most effective.