A simplified post preparation technique after Thermafil obturation: evaluation of apical microleakage and presence of voids using methylene blue dye penetration

Abstract

Aim. To evaluate the apical microleakage of Thermafil obturations after three different post space preparation techniques.

Materials and methods. 33 root canals of monoradiculated extracted teeth were prepared with M two and then obturated with Thermafil. Teeth so treated were then divided into three groups and the post space to middle root was prepared using three different techniques. In samples in group A the housing for the post was created using a Torpan bur, and the carrier was partially removed only in the coronal portion. In samples in group B the carrier was completely removed and gutta-percha was hand compacted, before canal preparation using a Torpan bur. In samples in group C the carrier was completely removed, without guttapercha compaction, before canal preparation using a Torpan bur. The roots were immersed for 72 hours in methylene blue dye solution and sectioned transversely at 1-3-5 mm from the apex for evaluation of dye penetration using a stereomicroscope. The data collected were processed using Win CAD software and subjected to statistical analysis using the Student t test for p<0.05. Results. There were no significant differences between the three groups, except for the presence of voids in the intermediate section of teeth in groups B and C.

Conclusions. Post space preparation did not influence the apical seal, and gutta-percha without voids was always found in the last millimetre of the canal obturation. This study proposes a post preparation technique which provides for complete carrier removal using pliers, hand compaction of residual gutta-percha with a manual plugger and enlargement of the root canal, using appropriate post space burs, free of any interference from the carrier. Operating time is reduced, as is the risk of creating ledges or iatrogenic perforations.