Métodos de fotopolimeriza o

The objective of this study was to make a literature review about methods of photo polymerization of composite resins. The first utilized resins were chemically activated and presented some improprieties such as the limitation of working time and the insertion of spatulation bubbles. In order to by-pass such problems, photo activated systems were developed. The first instruments used ultra-violet light (U.V.) that operated as an activator of the polymerization reaction. As this type of light had a limited depth and deleterious effects on the operator and patient, people looked for a source that would proportionate a satisfactory photo polymerization without causing such problems. In this way, the sources of light for the photo polymerization became visible, such as halogen light, the laser of argon, the plasma arch and the LED. To get this fact, a very small intensity of light and a minimum period of time are necessary. The halogen light is the most used by dental surgeons, for this reason it is also called conventional light. It produces a light with energy within a wide band of wavelength, 400 to 500 nm, which allows a larger performance with the diverse materials available in the market. On the other side, the LED s are more durable and portable, but they have a more limited actuation due to their wavelength being between 450 and 490 nm.