OBJECTIVETo choose the best retraction agent for the clinic by evaluating the gingival inflammation related to three kinds of retraction agents.

METHODS40 maxillary premolars were divided into four groups according to the randomized block design: Ferric sulfate group, aluminum chloride group, epinephrine group, sodium chloride group(control group), each 10 teeth, respectively used 25% AlCl3, 15.5% Fe2(SO4)3, 0.1% HCl-epinephrine, sodium chloride as retraction agents. The quantity of gingival crevicular fluid (GCF) and the active level of aspartate amino-transferase (AST) in gingival crevicular fluid were measured before and 1, 3, 5, 7, 9 days after retracting gingiva by four kinds retraction agents. The changes of GCF were calculated.

RESULTSThe change of the GCF from the smallest to the largest was sodium chloride, 0.1% HCl-epinephrine, 25% AlCl,, 15.5% Fe2 (SO)3. Compared with sodium chloride, only 15.5% Fe2 (SO)3 in AST was the significant difference in the first day and the third day (P < 0.05). AST of ferric sulfate group after 1, 3 days greater than 800 IU.

CONCLUSION0.1% HCl-epinephrine is suggested in patient without cardiovascular disease. For patient with cardiovascular disease, the better substitute is 25% AlCl3. 15.5% Fe2 (SO4)3 will not be used until its concentration is fallen.