title: Effects of the addition of nanoparticulate calcium carbonate on setting time, dimensional change, compressive strength, solubility and pH of MTA.
abstract: OBJECTIVE
  To evaluate nanoparticulate calcium carbonate (NPCC) using transmission electron microscopy and the effects of NPCC addition to MTA in regard to the setting time, dimensional change, compressive strength, solubility and pH.
  
  
  METHODS
  The experimental groups were G1 (MTA), G2 (MTA with 5% NPCC) and G3 (MTA with 10% NPCC). The tests followed ISO and ADA standards. The specimens in the dimensional change and compressive strength tests were measured immediately after setting, after 24 h and after 30 days. In the solubility test, rings filled with cement were weighed after setting and after 30 days. The pH was measured after 24 h and 30 days. The data were analysed with the ANOVA, Tukey's and Kruskal-Wallis tests (α = 5%).
  
  
  RESULTS
  The setting time was reduced (P < 0.05) in samples from G2 and G3 compared to G1. After 24 h, the dimensional change was similar amongst the groups, and after 30 days, G2 was associated with less alteration than G1 and G3. There was a difference in the compressive strength (P < 0.001) after 24 h and 30 days (G1 > G2 > G3). The solubility test revealed a difference amongst the groups when the specimens were hydrated: G2 > G1 > G3 and dehydrated: G3 > G2 > G1. The pH of the groups was similar at 24 h with higher values in each group after 30 days (P < 0.05), and G2 and G3 had similar mean pH values but both were higher than G1.
  
  
  CONCLUSIONS
  Nanoparticulate calcium carbonate had a cubic morphology with few impurities. The addition of nanoparticulate calcium carbonate to MTA accelerated the setting time, decreased compressive strength and, after 30 days, resulted in lower dimensional change (G2), higher solubility and a higher pH.
authors.affiliation: Department of Dentistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Bernardi
authors.affiliation: Department of Dentistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: E A
authors.initials: EA
authors.lastname: Bortoluzzi
authors.affiliation: Department of Dentistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: W T
authors.initials: WT
authors.lastname: Felippe
authors.affiliation: Department of Dentistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: M C S
authors.initials: MC
authors.lastname: Felippe
authors.affiliation: Department of Materials Engineering, Federal University Ouro Preto, Minas Gerais, Brazil.
authors.forename: W S
authors.initials: WS
authors.lastname: Wan
authors.affiliation: Department of Dentistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: C S
authors.initials: CS
authors.lastname: Teixeira
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D019245:Compressive Strength; D003738:Dental Cements / Q000737:chemistry*; D004338:Drug Combinations; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D053758:Nanoparticles; D010087:Oxides / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D012995:Solubility
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D003738:Dental Cements; D004338:Drug Combinations; D010087:Oxides; D017640:Silicates; C086631:mineral trioxide aggregate; D002119:Calcium Carbonate
keywords: mineral trioxide aggregate; nanoparticulate calcium carbonate; physicochemical properties