Influence of the length of remaining root canal filling and post space preparation on the coronal leakage of Enterococcus faecalis

Ex vivo microbial leakage analysis of polytetrafluoroethylene tape and cotton pellet as endodontic access cavity spacers

BACKGROUND

The endodontic spacers are placed between the endodontic appointments or after completion of the endodontic therapy, and until the placement of a definitive restoration.

AIMS

The aim of this study was to evaluate the sealing ability of polytetrafluoroethylene (PTFE) access spacer against microbial leakage and to compare it with that of a cotton pellet.

MATERIALS AND METHODS

Fifty-two extracted human single-rooted premolars were divided into two experimental groups (n = 20) according to the endodontic spacer; cotton pellet or PTFE tape, and two control groups (n = 6). Following standardized access cavity, cleaning, and shaping procedures, the access cavities received a standardized thickness of the spacer material followed by a Cavit restoration in all the teeth except for the positive controls, which were left empty. Negative controls had the root surfaces completely sealed with nail polish. A dual-chamber microbial leakage model was used with Enterococcus faecalis as the test strain. At days 7 and 30, samples of the lower chambers' solution were obtained and subjected to the quantitative real-time polymerase chain reaction (qPCR) analysis to quantify bacterial levels. Furthermore, broth turbidity in the lower chambers was recorded weekly. The Mann-Whitney U test and Wilcoxon test were used to compare E. faecalis counts between and within groups, respectively.

RESULTS

At days 7 and 14, the experimental groups leaked similarly as determined by broth turbidity. However, at days 21 and 30, a significantly higher number of cotton pellet samples exhibited microbial leakage. Analysis by qPCR revealed higher levels of E. faecalis counts in cotton pellet samples compared with PTFE samples. This difference was statistically significant at day 7, but not at day 30.

CONCLUSIONS

PTFE spacer showed improved sealing ability compared with the commonly used cotton pellet and may serve as an alternative endodontic access cavity spacer.

Endodontic Treatment of a Tooth with Traumatic Fracture of Root Middle Third

Root fracture occurs in 0.5 to 7% of all dental injuries. Subsequent to this injury, the coronal segment is displaced, while the apical segment is rarely displaced. Emergency treatment involves repositioning of the coronal segment close to the radicular segment as much as possible to enhance the chance of pulp revascularization. If pulp necrosis occurs, the infective products cause an inflammatory response and radiolucency is seen at the fracture line. In the present case, the patient had two maxillary central incisors with horizontal middle third root fractures due to a traumatic accident four years earlier. The right central incisor showed an endodontic abscess due to pulp infection in the coronal segment. The coronal fragment was treated. In this case study all signs and symptoms resolved after treatment and three year follow-up showed a successful treatment outcome. The left central incisor had a vital pulp according to vitality tests, so "observation only" strategy was considered for this tooth.

Comparing the Coronal Seal of Different Thicknesses of MTA with Gutta-Percha after Post Space Preparation

INTRODUCTION

The aim of this study was to compare the coronal seal of different thicknesses of MTA with gutta-percha after post space preparation.

MATERIALS AND METHODS

A total of 50 maxillary central incisors randomly divided into 5 experimental groups (n = 8). After preparation of the root canals with step back technique, in groups 1 and 2, post spaces were prepared and 4 or 5 mm gutta-percha remained in the apical, respectively. In groups 3, 4, and 5, there was 1-2 and 3 mm MTA in the apical, respectively. The ten teeth serve as control groups. The teeth were connected to a bacterial microleakage evaluation system. The study period was 120 days and the samples were evaluated on ten-day intervals; Meier-Kaplan technique was used for estimation of the mean time of microleakage to occur. Log-rank test was used for comparison of microleakage.

RESULTS

Number of samples exhibiting microleakage in MTA was less than those of gutta-percha at all intervals. Means of days with no microleakage were maximum and minimum with 3 mm MTA and 4 mm gutta-percha, respectively.

CONCLUSION

Obturation of root canals using the MTA technique provides a proper seal with the minimum thickness of MTA in teeth requiring post space preparation.