RESUMO
PURPOSE: To study the rate of curing, three composites, Heliomolar (Vivadent), Z100 (3M), and Renew (Bisco) were investigated METHODS: Volumetric shrinkage was measured at 25 degrees C using the Acuvol with an RG610 red filter. The dynamic measurements were made in the single view mode. RESULTS: Detailed kinetic studies for Renew determined the effect of varying the light intensity (100mW - 500mW) and irradiation time (3 seconds - 30 seconds) on the rate of curing. A measurement of the gel time of composites and a kinetic constant is reported. ANOVA followed by a Fisher's LSD test and a Kruskall-Wallis test were used for analysis of the data. The gel times follow the order of Heliomolar > Renew > Z100 at 20 seconds and 500 mW. Irradiation time had no significant effect on the gel time of Renew. Light intensity had a significant effect on the gel time of Renew.
Assuntos
Resinas Compostas/química , Gravação em Vídeo/métodos , Resinas Acrílicas/química , Resinas Acrílicas/efeitos da radiação , Resinas Compostas/efeitos da radiação , Humanos , Processamento de Imagem Assistida por Computador/instrumentação , Processamento de Imagem Assistida por Computador/métodos , Cinética , Luz , Teste de Materiais , Metacrilatos/química , Metacrilatos/efeitos da radiação , Polímeros/química , Polímeros/efeitos da radiação , Poliuretanos/química , Poliuretanos/efeitos da radiação , Doses de Radiação , Dióxido de Silício/química , Dióxido de Silício/efeitos da radiação , Propriedades de Superfície , Fatores de Tempo , Gravação em Vídeo/instrumentação , Zircônio/química , Zircônio/efeitos da radiaçãoRESUMO
OBJECTIVE: This study involves investigation of the use of video-imaging for measurement of volumetric shrinkage of composites. METHODS: Six composites were tested for volumetric shrinkage using video-imaging. The volumetric shrinkage was measured using the single- and multi-view volumetric reconstruction modes. All composites were cured using a VIP(TM) curing light for 40s at 500 mW/cm(2). Dynamic shrinkage was measured using the single-view mode with a red filter placed over the detector opening. RESULTS: Analysis of the volumetric shrinkage values by a one way ANOVA for each composite showed no difference for the single- and multi-view measurement mode. The shrinkage values determined by video-imaging were compared to those measured for the same composites by mercury dilatometry by one way ANOVA followed by a paired comparison using the Bonferroni method. CONCLUSION: The video-imaging technique gives reproducible results for volumetric shrinkage of composites comparable to those measured by dilatometry.
