Evaluation of the dentinal wall adaptation ability of MTA Fillapex using stereo electron microscope

Comparative evaluation of sealing ability and adaptation of gel form of MTA to dentinal walls: an in-vitro study

CONTEXT

Mineral Trioxide Aggregate (MTA) is a calcium silicate-based cement that potentially exhibits improved washout resistance when carboxymethyl chitosan or gelatin is incorporated. Gel-form MTA is a novel mineral trioxide aggregate formulated using construction industry-based technology. The present study was conducted to comparatively evaluate the sealing ability and adaptation to dentinal walls of gel-form MTA.

MATERIALS AND METHODS

This in-vitro study consisted of two groups: gel-form MTA and the conventional powder-liquid MTA. 10 samples per group were used for each of the tested parameters. Adaptation of the MTA to the dentinal walls was tested under the light microscope and measured using Image J software. Sealing ability was evaluated using a single aerobic bacterial leakage model. Appropriate statistical analysis was done for the obtained data. Adaptation of the MTA was analyzed using independent t-test and Friedman test, whereas the bacterial leakage was analyzed using chi-square test.

RESULTS

On comparison of the adaptation property at coronal and apical thirds, there was no statistically significant difference between the groups (p = 0.071 and p = 0.638, respectively). However, while comparing the same in the middle one-third of the root, lesser gaps were identified in the gel-form MTA group (p = 0.013). One sample belonging to the conventional powder-liquid MTA group showed significant turbidity during bacteria leakage evaluation (p = 0.001) with the presence of E. faecalis in the count of 103 colony forming units/milliliter.

CONCLUSION

The gel-form MTA shows a better adaptation to the dentinal walls at the middle third of the root and exhibits better sealing ability against bacterial leakage when tested for E. faecalis. The adaptation of gel-form MTA at coronal and apical third of the root was comparable to the conventional powder-liquid MTA.

Comparison of push-out bond strength of endodontic sealers after root canal drying with different techniques

OBJECTIVES

An ideal endodontic sealer should bond to both dentin and root-filling material. This study aimed to assess the push-out bond strength (PBS) of mineral trioxide aggregate (MTA)-Fillapex, Endoseal MTA, AH26, and Sure-Seal Root to root dentin after root canal drying with different techniques.

MATERIALS AND METHODS

This in vitro study was conducted on 160 extracted mandibular premolars. After root canal preparation, the teeth were randomly divided into four groups (n = 40) of drying with ethanol, paper point, air vacuum, and control (wet canal). Each group was divided into four subgroups (n = 10) for use of AH26, Sure-Seal Root, MTA-Fillapex, and Endoseal MTA sealers. The mean PBS was measured by a universal testing machine. The mode of failure was determined under a stereomicroscope. Data were analyzed by the Kruskal-Wallis and Games-Howell tests.

RESULTS

The maximum mean PBS was equally recorded in ethanol and paper point groups, and was significantly higher than that of control and air vacuum groups (p < .001). In the use of AH26 sealer, the mean PBS in drying with ethanol was significantly higher than all other methods (p < .05). The mean PBS in drying with a paper point was also significantly higher compared with control and air vacuum methods (p < .05). In the use of Sure-Seal, the mean PBS in drying with a paper point was significantly higher than other methods (p < .05). The mean PBS in drying with ethanol was significantly higher than that in control and air vacuum methods (p < .001). In the use of MTA-Fillapex and Endoseal-MTA, the technique of drying had no significant effect on PBS. Adhesive and mixed failures were the most common in all drying groups.

CONCLUSIONS

Drying with ethanol and paper point enhanced the PBS of sealers to root dentin.

Successful Use of MTA Fillapex as a Sealant for Feline Root Canal Therapy of 50 Canines in 37 Cats

Intentional or unintentional pulp exposure of cat canines can lead to periapical disease, osteomyelitis, and oral pain. Root canal therapy (RCT) allows the retention of cat canines with pulp exposure by removing the infected pulp and replacing it with an inert material. This study used MTA Fillapex™ as a root canal sealant with gutta percha single cone obturation in 37 cats (50 canine teeth). Roots were classified as "successful," "no evidence of failure (NEF)," or "failed" at 6-month radiographic reviews. Therapy was considered "successful" if a preoperative periapical lucency had healed or not formed after treatment and any preoperative external inflammatory root resorption (EIRR) had stabilized without progression. Therapy was categorized as "NEF" if a periapical lucency had remained the same or decreased in size but not completely resolved and any preoperative EIRR had stabilized without progression. "Failed" if a periapical lucency had occurred or increased in size posttreatment or if EIRR had developed or progressed posttreatment. Thirty-two canine teeth (64%) were classified as "successful," 14 canine teeth (28%) were classified as "NEF," and 4 canine teeth (8%) were classified as "failed". The study concluded that RCT using MTA Fillapex as a root canal sealant is a suitable endodontic treatment for fractured cat canines, especially those that are periodontally or endodontically challenged.

Bacterial Leakage of Four Endodontic Sealers Using Fresh Human Saliva

Introduction

Bacterial leakage plays a considerable role in endodontic related failures. The aim of this study was to compare the bacterial leakage of bioceramic (including Well Root ST and MTA Fillapex) and resin-based root canal sealers (naming AH-Plus and AdSeal).

Methods and Materials

Sixty-eight maxillary central incisors were included in this experimental study. These were randomly allocated into four experimental groups, which were obturated with gutta-percha and four different sealers (n=15), and the two control groups (positive, n=4 and negative, n=4). A dual-chamber technique was carried out using fresh human saliva and traced for 90 days. The Chi-square and Long Rank tests were performed for data analysis.

Results

Bacterial leakage was observed in 33.3% of the samples in Well Root ST, 40% in AH-Plus group, 53.3% in AdSeal group, and 66.6% in MTA Fillapex group. The difference between the Well Root ST and MTA Fillapex groups was significant (P=0.02). The mean leakage time between the Well Root ST (85.6 days) and MTA Fillapex groups (71.2 days) was also significant (P=0.037).

Conclusion

The results of this in vitro study revealed bacterial leakage in all experimental groups. The Well Root ST and the MTA Fillapex groups showed the lowest and highest bacterial leakages, respectively. Then it seems that the Well Root ST is a good substitute for MTA Fillapex in clinical applications.