Depth of Cure and Efectiveness of Curing Light Apparatus (ISO)

Objectives: The purpose of this study was to verify the depth of cure of four resin-based compounds when polymerized with two curing light sources (Halogen and LED) and at two exposure times. The polimerization appraisal of the compounds was carried out in compliance with ISO standards. Methods: Thus, eighty cylindrical stainless steel material samplers were made and attached to a glass slab and filled in a single increment with the composites (Esthet-X, Filtek P-60, Durafill, and Charisma). Each cylinder was submitted to the light emitted by the light curing apparatus during 20 or 40 seconds, according to the group under study. The composite non-endutated after exposure to the light source was then removed and the remainder was measured. In order to ascertain curing depth the total length of the remainder of the material sampler being measured was divided by two , as ISO norms state that the ideal polymerization depth should be 50% of the total lenght of the indurated sample. Results: Therefore, the sampler materials considered adequately light cured were those which, on being exposed to light curing for the time recomended by the respective manufacturers of the resin compounds , yelded the final measurement of 1,5mm or more in length. Conclusions: The material cured by LED and Halogen light apparatuses in both the proposed curing times reached the standard stablished by ISO 4049 norms. Both curing lights reported an adequate performance regarding depth of cure. The LED tecnology proved to be suitable as regards polymerization of all the tested resin-besed composites.