The effects of pressure in vitro on three methods of root canal obturation.

INTRODUCTION The seal of root canal fillings depends on the anatomy of the root canal system and on the properties of filling materials and their bond to the walls of the root canal. Alterations in pressure may influence these properties. The current study investigated and compared microleakage in a tapered single-cone method versus lateral and vertical condensation after diving simulation. METHODS One hundred and thirty five extracted single-rooted teeth were used. Following instrumentation and irrigation to #30.06 Mtwo rotary system, obturations were performed in three groups of 45 teeth: Group 1, tapered single-cone with Endoseal MTA sealer; Group 2, lateral condensation with AH26 sealer; Group 3, vertical condensation with AH26 sealer. Then all specimens were divided into three groups and incubated at ambient room pressure (101.3 kPa), 203 kPa or 304 kPa for 120 minutes respectively 20 times over one month to simulate diving conditions. Microleakage quantitative analysis was recorded by using a 2% Methylene blue dye for 24 hours. RESULTS The amounts of microleakage increased with increasing pressure in all obturation groups; however, the differences were not statistically significant (P > 0.05). At all three pressures, the least microleakage was recorded in Group 3, vertical condensation. Although the differences between vertical condensation, lateral condensation, and tapered single-cone methods were statistically significant (P < 0.001), the vertical condensation and lateral condensation groups did not differ from each other (P > 0.05). CONCLUSIONS Vertical condensation may be the best technique, based on sealing ability, for people who frequently experience pressure alterations.