Análise da integridade física e do desempenho de fontes fotoativadoras em clínica-escola

Abstract

The longevity of dental restorations is related to the degree of conversion of composites into polymers, obtained through photopolymerization performed by light-curing units. Insufficient conversion can compromise the clinical performance and durability of the restorations. The irradiance at the active tip, expressed in mW/cm2, is the ratio between the emitted power and the light-emitting area. Power is measured using radiometers, which are used for the appropriate selection of the light source and for monitoring its maintenance during clinical use, especially in educational institutions. This study aimed to evaluate the performance of the light-curing sources available at UFJF-GV regarding physical integrity and irradiance values, obtained by different measurement methods. To this end, all the institution's photoactivation sources were evaluated, classified according to their physical integrity, and the results of two measurements were used. The first measurement was performed with a portable clinical radiometer, measuring 29 sources, where 13.8% were >1000 mW/cm2, 58.6% between 500 and 1000 mW/cm2, and 27.6% <500 mW/cm2. The second measurement, using the Mini-Gig, considered the gold standard, with a six-month interval between evaluations, assessed a total of 31 photoactivation sources. Of these, 29 (93.5%) had <500 mW/cm2 and 2 (6.5%) were between 500 and 1000 mW/cm2. The evaluation of 41 devices regarding physical integrity revealed 12 "without damage," 17 as "minor damage," and 12 presenting "critical damage." The results showed deterioration of the active tips in a short period, indicating the need for educational interventions, such as the provision of instructional materials, periodic training, and standardization of cleaning routines.