Faculty Collaboration Database

Effect of additives on mineral trioxide aggregate setting reaction product formation. J Endod 2015 Jan;41(1):88-91

Date

09/15/2014

Pubmed ID

25218527

DOI

10.1016/j.joen.2014.07.020

Scopus ID

2-s2.0-84916912273 (requires institutional sign-in at Scopus site)   24 Citations

Abstract

INTRODUCTION: Mineral trioxide aggregate (MTA) sets via hydration of calcium silicates to yield calcium silicate hydrates and calcium hydroxide (Ca[OH]2). However, a drawback of MTA is its long setting time. Therefore, many additives have been suggested to reduce the setting time. The effect those additives have on setting reaction product formation has been ignored. The objective was to examine the effect additives have on MTA's setting time and setting reaction using differential scanning calorimetry (DSC).

METHODS: MTA powder was prepared with distilled water (control), phosphate buffered saline, 5% calcium chloride (CaCl2), 3% sodium hypochlorite (NaOCl), or lidocaine in a 3:1 mixture and placed in crucibles for DSC evaluation. The setting exothermic reactions were evaluated at 37°C for 8 hours to determine the setting time. Separate samples were stored and evaluated using dynamic DSC scans (37°C→640°C at10°C/min) at 1 day, 1 week, 1 month, and 3 months (n = 9/group/time). Dynamic DSC quantifies the reaction product formed from the amount of heat required to decompose it. Thermographic peaks were integrated to determine enthalpy, which was analyzed with analysis of variance/Tukey test (α = 0.05).

RESULTS: Isothermal DSC identified 2 main exothermal peaks occurring at 44 ± 12 and 343 ± 57 minutes for the control. Only the CaCl2 additive was an accelerant, which was observed by a greater exothermic peak at 101 ± 11 minutes, indicating a decreased setting time. The dynamic DSC scans produced an endothermic peak around 450°C-550°C attributed to Ca(OH)2 decomposition. The use of a few additives (NaOCl and lidocaine) resulted in significantly less Ca(OH)2 product formation.

CONCLUSIONS: DSC was used to discriminate calcium hydroxide formation in MTA mixed with various additives and showed NaOCl and lidocaine are detrimental to MTA reaction product formation, whereas CaCl2 accelerated the reaction.

Author List

Zapf AM, Chedella SC, Berzins DW

Author

David Berzins BS,PhD Graduate Program Director for Dental Biomaterials in the General Dental Sciences/Dental Biomaterials department at Marquette University

MESH terms used to index this publication - Major topics in bold

Aluminum Compounds
Calcium Chloride
Calcium Compounds
Calcium Hydroxide
Calorimetry, Differential Scanning
Drug Combinations
Lidocaine
Materials Testing
Oxides
Phosphates
Root Canal Filling Materials
Silicates
Sodium Chloride
Sodium Hypochlorite
Surface Properties
Thermography
Water