Effect of Gingival Displacement Cord on the Closure Rate of Gingival Crevice: Meta-analysis

Background: Gingival displacement is done before making impressions for crown & bridge teeth preparations. The gingival crevice should remain opened until we make impression. The closure rate of gingival crevice is not clearly mentioned in the literature. Purpose: To access the closure rate of gingival crevice after different gingival displacement cords are removed. Date Sources: Google Scholar Beta, PubMed (MEDLINE), EMBASE (Ovid), Cochrane Central Register of Controlled Trials (CENTRAL), manual search of retrieved references or other reviews, theses, unpublished studies and study authors. Study Selection: We included all clinical studies relating to closure rate of gingival crevice, in all languages, with no filters regarding the type of study because very limited data assumed to be available. Data Extraction: Two independent investigators (AS & BA) extracted the data. Data Synthesis & Conclusion: The closure rate of gingival crevice decreases with time. If gingival displacement is done using displacement cord for 5 to 6 minutes, the average crevice width was found to be 0. 22 mm at 60 sec, this is sufficient time for making impression.