Evaluation of temperature changes in the pulp chamber during polymerization of light-cured pulp-capping materials by using a VALO LED light curing unit at different curing distances

Abstract

The aim of this study was to evaluate temperature changes in the pulp chamber during polymerization of four different pulp-capping materials using a LED-light-curing-unit in the contact and noncontact positions. A pulpal circulation mechanism was simulated to measure increases in temperature in four pulp-capping materials that were applied to the occlusal dentin surface. Two different distances were used between the tip of the unit and the material surface during polymerization; 0 and 2 mm. The data were statistically analyzed using factorial-ANOVA, one-way-ANOVA, and Tukey's HSD test. There were statistically differences between contact and noncontact groups (p<0.05). Contact groups produced significantly lower temperature rise compared with noncontact groups. The highest and lowest mean temperature increases were calculated for the Biner LC and the TheraCal LC, respectively. Considering the effects of temperature rising, the distance of the light curing units from restorations should not be overlooked as well as the types of the materials.

Intrapulpal temperature changes during curing of different bulk-fill restorative materials

“…The sample size was calculated at a 95% confidence interval and a significance level of 0.05 (effect size=1.37), according to the study by Savas et al 29) . Although their data suggested that a total of 21 specimens would be adequate for analysis, a worstcase scenario was proposed, with an effect size of 0.6.…”

“…The intrapulpal temperature changes during the curing/setting of the bulk-fill restorative materials were determined with a device that simulated pulpal blood microcirculation [28][29][30] . This device consisted of a fixed mechanism providing the circulation of distilled water, at room temperature, with a flow rate of 0.026 mL per min, in the pulp chamber of the specimens 31) .…”

Variação da temperatura no interior da câmara pulpar em função de diferentes fontes de luz e camadas de resina composta. In vitro

“…Outro fator que pode influenciar o aumento de temperatura intra câmara pulpar é a espessura da dentina remanescente e, no presente estudo, a mesma foi padronizada em 1mm (Pameijer et al, 1991;Hannig e Bott, 1999;Daronch et al, 2007;Choi et al, 2014;Savas et al, 2014), simulando uma situação clínica crítica de cavidade profunda. A aferição desta feita através do especímetro inserido na câmara pulpar e na parte vestibular, metodologia esta utilizada também por Martins et al (2006).…”

“…Desta forma, a ponta das fontes de luz foi posicionada em contato com uma tira de poliéster apoiada na superfície, com o intuito de simular uma situação crítica. Savas et al, (2014), posicionaram a ponta do aparelho fotopolimerizador de luz visível sobre as resinas, encostando-se à tira matriz de poliéster que as protegia e ativando-as por 20, 40 e 60s . Outros autores defendem que não é prudente colocar fontes de luz com alta intensidade em contato direto com o substrato dentinário (Loney e Price, 2001).…”

“…No entando a reação exotérmica de polimerização também deve ser considerada (Lloyd et al, 1986;Smail et al, 1988;Shortall e Harrington, 1998;Savas et al, 2014). Os valores de temperatura obtidos durante a primeira fotoativação dos incrementos de resina composta com a luz halógena foram excluídos da avaliação entre as fontes de luz a fim de eliminar esta variável.…”