Fabio A P Rizzante1, Rana A F Sedky2, Adilson Y Furuse3, Sorin Teich4, Sérgio K Ishikiriama5, Gustavo Mendonça6. 1. Assistant Professor, Department of Comprehensive Care, Case Western Reserve University, School of Dental Medicine, Cleveland, Ohio. 2. Assistant Lecturer, Department of Operative Dentistry, Faculty of Dentistry, Ain Shams University, Cairo, Egypt. 3. Assistant Professor, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil. Electronic address: furuse@usp.br. 4. Associate Professor, Department of Comprehensive Care, Case Western Reserve University, School of Dental Medicine, Cleveland, Ohio. 5. Associate Professor, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil. 6. Associate Professor, Department of Biologic and Material Sciences, Division of Prosthodontics, University of Michigan School of Dentistry, Ann Arbor, Mich.
Abstract
STATEMENT OF PROBLEM: A reliable and validated protocol for nondestructive analysis of the entire restorative interface that could be applicable in studies assessing the adaptation of direct and indirect restorations is lacking. PURPOSE: The purpose of this in vitro study was to validate a 3D protocol for microleakage assessment in class II mesio-occluso-distal (MOD) cavities restored with composite resin. MATERIAL AND METHODS: Sixteen human third molars received standardized class II MOD preparations with cervical margins located 1 mm apical to the cemento-enamel junction. The specimens were restored with Filtek Bulk Fill Posterior (FBP) or Filtek Bulk Fill Flowable (FBF) and submitted to 10 000 thermocycles (5 °C and 55 °C with a 30-second dwell time at each temperature and 5-second transfer time). The specimens were scanned with microcomputed tomography (μCT) before and after immersion in 50% ammoniacal silver nitrate solution for 12 hours. Scanned data were processed, and the 3D amount of infiltrated silver nitrate was analyzed through the entire adhesive interface. In addition, the linear distance of silver nitrate infiltration was assessed using 3 axial images obtained from each specimen proximal box (2D analysis). Data were tested for homogeneity by using the Shapiro-Wilk test and evaluated by using 1-way ANOVA, followed by the post hoc Tukey HSD test (α=.05). RESULTS: FBP showed significantly lower leakage than FBF for both 2D and 3D analyses. A low correlation was observed between the assessment methods. CONCLUSIONS: Three-dimensional analysis of microleakage using μCT is a predictable and more reliable method for nondestructive and comprehensive analysis of the entire specimen.
STATEMENT OF PROBLEM: A reliable and validated protocol for nondestructive analysis of the entire restorative interface that could be applicable in studies assessing the adaptation of direct and indirect restorations is lacking. PURPOSE: The purpose of this in vitro study was to validate a 3D protocol for microleakage assessment in class II mesio-occluso-distal (MOD) cavities restored with composite resin. MATERIAL AND METHODS: Sixteen human third molars received standardized class II MOD preparations with cervical margins located 1 mm apical to the cemento-enamel junction. The specimens were restored with Filtek Bulk Fill Posterior (FBP) or Filtek Bulk Fill Flowable (FBF) and submitted to 10 000 thermocycles (5 °C and 55 °C with a 30-second dwell time at each temperature and 5-second transfer time). The specimens were scanned with microcomputed tomography (μCT) before and after immersion in 50% ammoniacal silver nitrate solution for 12 hours. Scanned data were processed, and the 3D amount of infiltrated silver nitrate was analyzed through the entire adhesive interface. In addition, the linear distance of silver nitrate infiltration was assessed using 3 axial images obtained from each specimen proximal box (2D analysis). Data were tested for homogeneity by using the Shapiro-Wilk test and evaluated by using 1-way ANOVA, followed by the post hoc Tukey HSD test (α=.05). RESULTS: FBP showed significantly lower leakage than FBF for both 2D and 3D analyses. A low correlation was observed between the assessment methods. CONCLUSIONS: Three-dimensional analysis of microleakage using μCT is a predictable and more reliable method for nondestructive and comprehensive analysis of the entire specimen.