Abstract

GONCALVES MOTA, E et al. Influencie of post-curing in Ormocer^® mechanical properties. Av Odontoestomatol [online]. 2006, vol.22, n.5, pp.271-277. ISSN 2340-3152.

The purposes of this study were evaluate and compare the influence of post-curing with heat and steam pressure or heat and nitrogen pressure in the compressive strength, elastic modulus and Vickers microhardness of an Ormocer^®; composite resin. Forty-five cylindrical samples with 3 mm diameter and 6 mm high were manufacture using a PTFE mould. The composite resin Admira (Voco, Cuxhaven, Germany) was inserted incrementally and cured for 40 s with XL-1500 (3M ESPE, St. Paul, MN, EUA). After that, the samples were stored in a stove at 37ºC for 24 hours and randomly divided in three groups. The samples of group I (control) were tested just after the stored period. In group II, the samples were submitted to 120ºC with water steam for 20 min, and for group III, the samples was post-cured at 140°C under 60 lbs of nitrogen for 10 min. The samples were tested with universal testing machine (Emic DL 2000, São José dos Pinhais, Paraná, Brazil) at 0.5 mm/min until fracture. Data of compressive strength (MPa), elastic modulus (GPa), and Vickers microhardness (VHN) were statistically evaluated with ANOVA/Tukey (p < 0.05). The mean values of compressive strength (SD) were: group I (control) 114.25^b (±34.74); group II 127.64^b (±33.27); group III 167.97a (±40.15); elastic modulus (SD): group I (control) 6.11^b(±3.5); group II 8.45^ab (±3.34); group III 11.31a(±4.7); Vickers microhardness (SD): group I (control) 47.26^b (2.7); group II 58.63a (2.3) and group III 63.69a (3.5). It is possible to conclude that the post-curing method at 140°C under 60 lbs of nitrogen improved significantly the compressive strength, and both methods improved the elastic modulus and microhardness (p < 0.05).

Keywords : Ormocer^®; post-curing; compressive strength; elastic modulus and Vickers microhardness.

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