Bacterial Leakage of Mineral Trioxide Aggregatebased and Resin-based Sealers in Teeth Ready for Root Retainers

Research Article

J Dent App. 2015;2(5): 214-218.

Bacterial Leakage of Mineral Trioxide Aggregatebased and Resin-based Sealers in Teeth Ready for Root Retainers

Flávia Sens Fagundes Tomazinho*

Professor, Endodontia - Universidade Positivo, Brazil

*Corresponding author: Flávia Sens Fagundes Tomazinho, Professor, Endodontia - Universidade Positivo, Brazil

Received: January 29, 2015; Accepted: March 11, 2015; Published: March 13, 2015


Aim: To perform an in vitro experiment to compare the sealing capability of a mineral trioxide aggregate (MTA) Fillapex sealer and an AH Plus sealer after root canal preparation for root canal pins.Methods: Forty-four lower premolar roots were biomechanically prepared, and the diameter of the cervical, middle, and apical thirds were standardized. The roots were sterilized, and the subsequent steps were conducted in a laminar flow booth. The specimens were filled by the lateral condensation technique with MTA Fillapex or AH Plus sealers, and the filling material was removed immediately after filling by leaving two different lengths (4 mm or 8 mm) of the remaining root filling. Four roots made up the positive and negative controls. The specimens were then inserted into a dual chamber device and placed in contact with sterile brain-heart infusion broth. The roots were inoculated with 1 × 107 colony-forming units/mL of Enterococcus Faecalis, and the bacterial suspension was maintained in contact with the filling and renewed every 48 h, with daily observation for 60 days. The data were analyzed by the Kaplan-Meier survival test. The filling sealers and the remaining filling were analyzed with a Chi-square test at a significance level of 5%. Results: Comparison of the MTA Fillapex and AH Plus sealers and filler lengths relative to time of contamination was not significantly different (p = 0.519), despite the smaller frequency of infiltration that was observed in the roots filled with MTA Fillapex with the 8-mm remaining filling. Conclusion: Despite the infiltration of E. faecalisin all of the conditions, the length of the remaining root and the time until infiltration were positively correlated as the time that was required for bacterial infiltration was greater in the group with the 8-mm-long remaining material compared to the group with the 4-mm-long remaining material.

Keywords: Enterococcus faecalis; Dental infiltration; Root canal treatment


MTA: Mineral Trioxide Aggregate


One of the desirable physicochemical properties of endodontic sealers is that they adhere to the dentin walls of root canals [1], and then hermetic filling can be obtained through root canal sealing to avoid fluid percolation into the periapical tissue [2]. In addition, antibacterial properties are desirable in order to prevent endodontic reinfection.

The use of endodontic sealers that are associated with guttapercha is currently considered a standard procedure in endodontic filling [3], mainly due to the lack of adherence of the gutta-percha to the dentin walls. The draining properties of the endodontic sealer must also be taken into consideration so that the spaces between the filling material and the root wall can be filled, thus providing higher sealing quality [2].

The sealer capacity for maintaining the apical seal can become more evident when there is a need to perform a preparation for root retainers, as the material may move during the mechanical preparation [4].

During the interval between the preparation of the canal for the retainer and its installation, the coronal portion of the dental element remains, for the most part, sealed only by a temporary material. Such material typically provides low resistance and may move due to the movements and forces employed during chewing, thus leaving the canal passage exposed to the oral environment and enabling root canal contamination by microorganisms. The need to partially unfill the root canal and prepare it to receive a pin can accelerate bacterial microleakage once the sealed portion is around 3–5 mm. Resistant microorganisms such as Enteroccocus faecalis may remain in these spaces or even reach apical tissues through the dentin interface and filling material, thereby resulting in the acute deterioration of periapical lesions and the consequent failure of the endodontic treatment.

Several studies have considered coronal infiltration an important cause of endodontic treatment failure. It has been shown that filled roots that are exposed to the oral cavity are invariably contaminated by fluids, bacteria, and bacterial by-products. Long-term contamination may lead to failure of the endodontic treatment and compromise the prosthetic/restorative treatment as a whole [5].

The lack of endodontic sealers that have all of the ideal physicochemical properties has encouraged the development of a wide variety of materials, including materials that have been developed for greater adhesion, such as the AH Plus sealer, and those that have been developed for better performance of the biological properties and sealing [6], such as the MTA Fillapex sealer, which was developed from a mineral trioxide aggregate (MTA).

Therefore, the aim of this study was to perform an in vitro experiment to compare the sealing capability against E. faecalis of AH Plus and MTA Fillapex sealers after root canal preparation for root canal pins for a trial period of 60 days.

Material and Methods

This study was approved by the Human Research Ethics Committee of Positivo University (Protocol #088/11).

Selection and preparation of specimens

For this study, 44 single-rooted human permanent premolars with straight roots were selected. The sampled teeth had a minimum root length of 11 mm, a whole root apex, and no endodontic treatment, bone resorption, or calcifications. The teeth were kept in 0.1% Thymol solution at 4°C.

The specimens were washed in running water for 24 h to remove all traces of the Thymol solution, and the length of the root was standardized at 11 mm. The working length (WL) was standardized at 10 mm. The cervical portion of the root was prepared with a Gates Glidden drill #6. The roots were instrumented by manual instruments (K-file, DentsplyMaillefer, Ballaigues, Switzerland), with the crowndown technique, with the following file sequence: #80, # 70, and with an apical stop diameter of #60 for all elements. The irrigating solution used during the entire preparation was 2.5% sodium hypochlorite (AsferIndústriaQuímica Ltda., São Caetano do Sul, São Paulo, Brazil), and the final irrigation was performed with 10 mL of 17% ethylenediaminetetraacetic acid solution (Pharmacy-School Positivo University, Curitiba, Paraná, Brazil), which was followed by irrigation with 10 mL of distilled water and the drying of the canals with absorbent paper (Dentsply-Maillefer, Petrópolis, Rio de Janeiro, Brazil).

After the preparation, the samples were autoclaved at 120°C for 20 min (Cristófoli Autoclave Vitale 12 model, Campo Mourão, Paraná, Brazil). After this step, all of the procedures were conducted in a laminar flow chamber to maintain sterility.

The specimens were randomly, double blinded, divided into 2 experimental groups (n = 20) according to the endodontic sealer: Group I, AH Plus (Dentsply De Trey GmbH, Konstanz, Germany) or Group II, MTA Fillapex (Angelus, Londrina, Paraná, Brazil). Composition of the sealers is shown in Table 1.