Elsevier

Journal of Endodontics

Volume 39, Issue 3, March 2013, Pages 402-405
Journal of Endodontics

Basic Research
In Vitro Assessment of Mineral Trioxide Aggregate Setting in the Presence of Interstitial Fluid Alone

https://doi.org/10.1016/j.joen.2012.11.010Get rights and content

Abstract

Introduction

The aim of this study was to determine the ability of white mineral trioxide aggregate (MTA) Angelus (Solucoes Odontologicas, Londrina, Brazil) to set in 24 hours within the root canal in the presence of an intrinsic moisture source (interstitial fluid) alone without the need for moist cotton pellet placement.

Methods

Extracted teeth were used to simulate the open apex situation. MTA was placed to a depth of 4 mm and allowed to set for 24 hours in the following test groups: a current protocol group with a moist cotton pellet, a test group with no moist cotton pellet placement, and positive and negative control groups with varnished roots. The teeth were embedded in florist sponges immersed in fetal bovine serum at 13.3-kPa pressure. The MTA set was tested using the Vickers hardness test, and the data were analyzed using analysis of variance.

Results

The greatest mean surface hardness values were observed in the current protocol group (80.7 ± 35.6), but this was not statistically different when compared with the test group without a moist cotton pellet (78.3 ± 53.7) or the control groups.

Conclusions

Moist cotton pellet placement may not be essential for MTA setting in apexification procedures or situations in which the apical surface of the MTA is against a moist opening of greater than 1 mm.

Section snippets

Materials and Methods

Approval for this project was granted by the Human Research Ethics Committee of the University of Melbourne, Melbourne, Australia. Fifty-four single-rooted teeth were collected from the Royal Dental Hospital of Melbourne tooth bank and were radiographed in the buccolingual and mesiodistal planes to confirm the absence of more than 1 canal, resorption, caries, root fractures, calcifications, or anomalies of the pulp 11, 12. The teeth were stored in formaldehyde (11) before commencement of the

Results

The results of hardness for the different experimental groups as measured by the Vickers hardness test are presented in Table 1 and Figure 2. The greatest mean surface hardness value (VHN = 80.7 ± 35.6) was observed in the group with conditions reflecting the current recommended protocol for the use of MTA (ie, the placement of the wet cotton pellet but no varnish). This was only marginally greater than the main test group with no varnish and no moist cotton pellet (VHN = 78.3 ± 53.7). A 1-way

Discussion

This study indicates that applying a moist cotton pellet to the top of the setting MTA may be an unnecessary extra step and supports recent findings that the restoration of the tooth may proceed without needing the MTA to set (10). This result can be extrapolated to other clinical situations in which the apical surface of the MTA is exposed to tissue fluids and is at least 1 mm in diameter, such as root or pulp chamber perforations. The actual relationship between the diameter and setting was

Conclusions

There was no significant difference between the current protocol group with moist cotton pellet placement and the test group. From this and previously published data 6, 11, it can be concluded that moist cotton pellet placement over MTA in apexification procedures or perforations greater than 1 mm may not be required to aid in the setting of MTA.

Acknowledgments

The authors would like to thank The Melbourne Dental School; Mr Ilya Zalizniak, Biomaterials/Biomechanics Technical Assistant, The University of Melbourne; Mr Mario Smith, Preclinical Laboratory, The University of Melbourne; and Associate Professor Ian Gordon of the Statistical Consulting Centre, University of Melbourne, for their generous support.

The authors deny any conflicts of interest related to this study.

Cited by (9)

  • Bleaching of a Discolored Tooth with Retrieval of Remnants after Successful Regenerative Endodontics

    2018, Journal of Endodontics
    Citation Excerpt :

    Similar to another report (38), the MTA barrier was removed before the placement of the bleaching agent. The set MTA adds support to the existing evidence and advice that a moist cotton pellet is not necessary for the setting of MTA (7, 8, 39). A recent in vitro study (40) showed continued release of hydrogen peroxide from a mixture of sodium perborate and water for up to 28 days.

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Supported by Gunz Dental (Australia), Dentsply (Australia) Research Fund, Dental Health Services Victoria Research and Innovation Grant, and The Melbourne Dental School.

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