Relevance of In-vitro Endodontic Sealer Solubility Tests - Systematic Review

Objectives: To systematically review the evidence on the applicability of current in vitro solubility tests to estimate endodontic sealer dissolution during a clinical extrusion scenario.
Methods: A systematic search of the literature on endodontic sealer solubility tests was conducted using MEDLINE (until October-2016). Studies specifically dealing with endodontic sealer solubility were selected and their evidence level was graded (as low, medium, or high) independently by the investigators following systematic data extraction and evidence synthesis based on the PRISMA guidelines.
Results: The Medline search retrieved 4073 articles; of these, 3918 were excluded for not being in English or for not dealing with the subject matter of this study. Following full-text screening of the remaining 155 articles, 48 papers that dealt specifically with the study of endodontic sealer solubility were retained for data extraction and evidence synthesis. Of these articles, 7 were graded as having moderate and 41 as low quality of evidence (none high). The majority of the studies graded as low had small sample sizes (n<10) and/or presented insufficient details to allow replicability. Most studies did not report dissolution over a period of time and none were designed to approximate the real-life clinical extrusion scenario.
Conclusions: There is low evidence to support the relevance and applicability of the available solubility tests for all categories of currently used endodontic sealers. The available tests do not seem to be optimal for estimating time-dependent dissolution of clinically extruded sealers. Alternate methods to evaluate extruded sealer dissolution over time are needed, which should preferably establish an in vitro testing condition that more closely approximates the clinical scenario.