Influence of plasma arc and quartz-tungsten-halogen curing lights on the polymerization of orthodontic composite resin

Authors

  • Telmo Bandeira Berthold PUCRS
  • Guilherme Cerveira Pontifical Catholic University of Rio Grande do Sul
  • Roger Berthold Pontifical Catholic University of Rio Grande do Sul
  • Luciane Hahn Private practice
  • Ana Maria Spohr Pontifical Catholic University of Rio Grande do Sul
  • Ernani Menezes Marchioro Pontifical Catholic University of Rio Grande do Sul

Keywords:

Composite resin, degree of conversion, hardness, PAC, QTH

Abstract

Purpose: To analyze, in vitro, the influence of a quartz-tungsten-halogen (QTH) and a plasma arc (PAC) on the degree of conversion and hardness of a composite resin, as well as the heat generated by the units. Methods: Transbond XT disks were prepared and light-cured for 10, 20 and 30 seconds with a QTH (Curing Light XL 3000) or with a PAC (Apollo 95E) for 1, 2 and 3 seconds. The composite resin polymerization was evaluated by infrared spectrophotometry (FTIR) and Knoop hardness number (KHN). The temperature at the curing tip was evaluated. The results were analyzed using ANOVA and Tukey test (alpha=0.05). Results: According to FTIR and KHN, the polymerization of the composite resin was statistically higher with the QTH. The temperature obtained with the QTH 20 s (45.44 oC) and 30 s (45.84 oC) was statistically higher than the QTH 10 ss (39.90 oC). The PAC 1 s (27.12 oC), 2 s (28.48 oC) and 3 s (29.96 oC) presented the lowest temperature and did not differ statistically among them. Conclusion: Transbond XT light-activated for 10, 20 and 30 seconds with the QTH presented higher degree of conversion and hardness in comparison with those obtained with the PAC for 1, 2 and 3 seconds, and the QTH generated more heat than the PAC.

Author Biography

Telmo Bandeira Berthold, PUCRS

Departamento de Prótese Dentária. Programa de Pós-Graduação em Odontologia. PUCRS

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