Abstract

GOMES FILHO, Edevilson Barbosa; MENEZES FILHO, Paulo Fonseca; VICENTE DA SILVA, Claudio Heliomar  and  COELHO SINHORETI, Mário Alexandre. Evaluation of the hardness Knoop of composite resin in function of the variation of the tecnique of complementary polimerazition. Acta odontol. venez [online]. 2008, vol.46, n.1, pp.20-24. ISSN 0001-6365.

Undoubtedly, a several of factors affected the microhardness of composite resins. The aim of this in vitro study was to investigate the influence of complementary polymerization on microhardness of a composite resin. 50 disk specimens were exposed to a halogen lamp for 40 seconds, and then complementary polymerization was made in the other four groups. Group 1 (control) - halogen lamp for 40 seconds; Group 2 (stove)- 120ºC; Group 3 - a cycle of 21 minutes in 121ºC and 1.5 atm; Group 4 (microwave) - 60% (560W) of total intensity for 3 minutes; Group 5 (experimental) - complementary polymerization with heat and light for 20 minutes on prototype. The results demonstrated that all groups, except the control group, presented higher Knoop microhardness values at the top surface when compared with the bottom, besides that the complementary polymerization increased the microhardness for tested groups, but in Group 5 (experimental) the prototype obtained the best performance with higher values of microhardness (59.97), with significant differences for the other groups.

Keywords : composite resin; Knoop hardness; complementary polimerization.