RESUMO
Retrograde surgery is a method to correct failures in endodontics, for which various materials are used. The purpose of this study was comparative evaluation of the amount microleakages of three retrograde cements: gray MTA, white MTA and Portland cement. In this experimintal study, 57 single root human extracted teeth with matu] apices, were selected. After cutting crowns, teeth were prepared with manual file [step back technique], they were obturated with gutta-percha and AH26 sealer laterally. Then roots devided into three experiment groups with 15 teeth in each group and 2 positive and negative control groups with 6 teeth in each group After a 45° bevel, 3mm apical cavities were prepared and then each one was filled with one of the three cements. The coronal part of the roots sealed with amalgam. After nail varnishing on the root surface [except their apical 1mm of each root]. All roots were immersed in 2% methylen-blue dye for 72 hrs. Then they were split and linear dye-penetration was measured by stereomicroscope. The data were analyzed statistical using one way ANOVA test.Statistic analysis of the data showed no significant difference between the three retrograde cemen Gray MTA [4.520mm] white MTA [4.826mm] and Portland cement [4.826mm].According to results, the use of Portland cement as a retrograde cement seems to be promising clinically. In vivo studies focusing on Portland cement are recommended