Introduction:

Coronal restoration following endodontic therapy prevents re-infection of the root canal system and is therefore vital for success.  A number of studies have examined coronal microleakage in endodontics.  The relationship between condensation technique and microleakage, however, is unclear.  Enterococcus faecalis, commonly isolated from failed root canals, has been shown to resist cleaning and shaping and survive as a monocolony in the root canal system. 

Objectives:

The purpose of this study was to test the ability of E. faecalis to compromise root canal systems obturated using lateral and vertical condensation techniques.

Methods:

64 human maxillary anterior teeth were decoronated 12 mm from the apex.  The canals were cleaned and shaped to apical size 35 using rotary Profiles and subsequently sterilized.  30 roots were obturated using lateral condensation, and 30 using vertical condensation.  The remaining 4 were positive/negative controls. The apices of all roots were immersed in BHI broth.  An E. faecalis suspension was placed at the coronal end and replenished every day.  All roots were incubated at 37°C.  Each day, the broth was observed for turbidity, indicating microleakage through the root canal system.

Results:

As in similar studies, all samples turned turbid by day 10.  The t-test was used to compare microleakage daily and the average time for each group to show contamination.  By day 2, 66% of samples obturated by vertical condensation turned turbid as compared with 33% of those obturated by lateral condensation. The average time for the lateral condensation group to show turbidity was 4.5 days, compared to 3 days for the vertical condensation group. These results were statistically significant (p<.05). 

Conclusions:

In this study, obturation by lateral condensation delayed bacterial microleakage longer than vertical condensation.  The results imply that lateral condensation provides better adaptation of filling and/or that vertical condensation may be more technique sensitive.