Mineral trioxide aggregate-based endodontic sealer stimulates hydroxyapatite nucleation in human osteoblast-like cell culture.
BACKGROUND
The main purpose of this study was to evaluate the biocompatibility and bioactivity of a new mineral trioxide aggregate (MTA)-based endodontic sealer, MTA Fillapex (MTA-F; Angelus, Londrina, Brazil), in human cell culture.


METHODS
Human osteoblast-like cells (Saos-2) were exposed for 1, 2, 3, and 7 days to MTA-F, Epiphany SE (EP-SE; SybronEndo, Orange, CA), and zinc oxide-eugenol sealer (ZOE). Unexposed cultures were the control group (CT). The viability of the cells was assessed by MTT assay and the morphology by scanning electron microscopy (SEM). The bioactivity of MTA-F was evaluated by alkaline phosphatase activity (ALP) and the detection of calcium deposits in the culture with alizarin red stain (ARS). Energy-dispersive X-ray spectroscopy (EDS) was used to chemically characterize the hydroxyapatite crystallites (HAP). Saos-2 cells were cultured for 21 days for ARS and SEM/EDS. ARS results were expressed as the number of stained nodules per area. Statistical analysis was performed with analysis of variance and Bonferroni tests (P < .01).


RESULTS
MTA-F exposure for 1, 2, and 3 days resulted in increased cytotoxicity. In contrast, viability increased after 7 days of exposure to MTA-F. Exposure to EP-SE and ZOE was cytotoxic at all time points. At day 7, ALP activity increase was significant in the MTA-F group. MTA-F presented the highest percentage of ARS-stained nodules (MTA-F > CT > EP-SE > ZOE). SEM/EDS analysis showed hydroxyapatite crystals only in the MTA-F and CT groups. In the MTA-F group, crystallite morphology and chemical composition were different from CT.


CONCLUSIONS
After setting, the cytotoxicity of MTA-F decreases and the sealer presents suitable bioactivity to stimulate HAP crystal nucleation.
Department of Restorative Dentistry, Dental School of São Paulo State University, Araraquara, São Paulo, Brazil.
Loise Pedrosa
LP
Salles
Ana Lívia
AL
Gomes-Cornélio
Felipe Coutinho
FC
Guimarães
Bruno Schneider
BS
Herrera
Sonia Nair
SN
Bao
Carlos
C
Rossa-Junior
Juliane Maria
JM
Guerreiro-Tanomaru
Mario
M
Tanomaru-Filho
D017607:Aluminum Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D000704:Analysis of Variance; D017610:Calcium Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003460:Crystallization; D004338:Drug Combinations; D017886:Durapatite / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000187:drug effects*; D010087:Oxides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D012387:Root Canal Filling Materials / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D017640:Silicates / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D013052:Spectrometry, X-Ray Emission; D018709:Statistics, Nonparametric; D014074:Tooth Calcification / Q000187:drug effects*
D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D017886:Durapatite