Author/Authors :
bahari, mahmoud tabriz university of medical sciences - dental and periodontal research center, dental faculty - department of operative dentistry, tabriz, iran , abed kahnamoui, mehdi tabriz university of medical sciences - dental faculty - department of operative dentistry, Tabriz, Iran , ebrahimi chaharom, mohammad esmaeel tabriz university of medical sciences - dental faculty - department of operative dentistry, tabriz, iran , kimyai, soodabeh tabriz university of medical sciences - dental faculty - department of operative dentistry, tabriz, iran , sattari, zeinab tabriz medical sciences university - dental faculty - department of operative dentistry, Tabriz, Iran
Abstract :
Background: Cention N has been introduced as an alternative material for amalgam. The purposewas to investigate the flexural strength and microhardness of this material in self‑cure and dual‑curemodes before and after thermocycling.Materials and Methods: In this experimental study, 40 samples of Cention N were preparedin order to determine and compare the microhardness. Half of the samples were set by self‑curemethod and the other half with dual‑cure method. The Vickers microhardness test was performedonce after 24 h and again after 10000 thermocyclings. Three‑point flexural test was used todetermine and compare the flexural strength of 52 rod‑shaped samples. Half of the samples wereset by self‑cure method and the other half with dual‑cure method. Among 26 samples in each group,13 samples were randomly selected and three‑point flexural test was performed after 24 h andfor another 13 samples after 10,000 thermocyclings. Data were analyzed using two‑way ANOVAand paired samples t‑test (P 0.05).Results: There was a statistically significant difference between the mean of microhardnessvalues in two curing methods (P 0.001) and in two storage conditions (P 0.001). The meanof dual‑cure microhardness (100.99 ± 7.22) was higher than that of self‑cure (64.61 ± 12.51)and the mean value associated with pre‑thermocycling (89.75 ± 15.84) was higher than thatof the post‑thermocycling (76.44 ± 23.56). There was no statistically significant differencebetween the mean flexural strength in the two curing methods (self‑cure [72.85 ± 16.26],dual cure [79.87 ± 23.07]; [P 0.05]). However, the mean flexural strength withoutthermocycling (85.98 ± 21.74) was higher than that of the thermocycled group (64.24 ± 6.40) (P 0.001).Conclusion: The microhardness of Cention N in dual‑cure mode was higher than that of self‑curemode, but the flexural strength of dual‑cure was not significantly different from that of self‑cure.Thermocycling had a significant effect on the microhardness and flexural strength.
Keywords :
Aging , composite resins , flexural strength , hardness , self‑curing of dental resins
