OBJECTIVE: This in vitro study compared the effects of different layering techniques and different monomer-based composites on microleakage. METHOD AND MATERIALS: Thirty-two freshly extracted caries-free human third molars were used. A wide mesio-occlusal-distal (MOD) cavity was prepared in each third molar, with the occlusal dimension being approximately two-thirds of the intercuspal dimension, and the cervical limit of one proximal box was stopped 1 mm below and the other 1 mm above the cementoenamel junction. The cavities were filled with a methacrylate-based nanohybrid composite (Grandio, VoCo) and a silorane-based microhybrid composite (Filtek Silorane, 3M ESPE). All samples were subjected to 1000 thermal cycles of 5 degrees C/55 degrees C in water with a 30-second dwell time and, after the procedure, the teeth were immersed in a 0.5% basic fuchsin dye at 23 degrees C for 24 hours. Sectioned samples were examined under a stereomicroscope (Leica MZ12, Leica Microsystems), and microleakage scores were statistically analyzed using the Kruskal-Wallis and the Mann-Whitney U tests. RESULTS: No microleakage was observed for silorane-based resin composite restorations. The nanohybrid-based resin composite restorations showed different levels of leakage. Statistical analysis of microleakage scores showed differences only at the enamel margins for nanohybrid material for both layering techniques (p < 0.05). The nanohybrid-based resin composite restorations showed better results with the vertical layering technique for enamel margins.
OBJECTIVE: This in vitro study compared the effects of different layering techniques and different monomer-based composites on microleakage. METHOD AND MATERIALS: Thirty-two freshly extracted caries-free human third molars were used. A wide mesio-occlusal-distal (MOD) cavity was prepared in each third molar, with the occlusal dimension being approximately two-thirds of the intercuspal dimension, and the cervical limit of one proximal box was stopped 1 mm below and the other 1 mm above the cementoenamel junction. The cavities were filled with a methacrylate-based nanohybrid composite (Grandio, VoCo) and a silorane-based microhybrid composite (Filtek Silorane, 3M ESPE). All samples were subjected to 1000 thermal cycles of 5 degrees C/55 degrees C in water with a 30-second dwell time and, after the procedure, the teeth were immersed in a 0.5% basic fuchsin dye at 23 degrees C for 24 hours. Sectioned samples were examined under a stereomicroscope (Leica MZ12, Leica Microsystems), and microleakage scores were statistically analyzed using the Kruskal-Wallis and the Mann-Whitney U tests. RESULTS: No microleakage was observed for silorane-based resin composite restorations. The nanohybrid-based resin composite restorations showed different levels of leakage. Statistical analysis of microleakage scores showed differences only at the enamel margins for nanohybrid material for both layering techniques (p < 0.05). The nanohybrid-based resin composite restorations showed better results with the vertical layering technique for enamel margins.
Authors: Carola A Carrera; Caixia Lan; David Escobar-Sanabria; Yuping Li; Joel Rudney; Conrado Aparicio; Alex Fok Journal: Dent Mater Date: 2015-01-30 Impact factor: 5.304
Authors: Renata Kirita Doi Sampaio; Linda Wang; Rodrigo Varella de Carvalho; Eugenio José Garcia; Andréa Mello de Andrade; Celso Afonso Klein-Júnior; Rosa Helena Miranda Grande; Sandra Kiss Moura Journal: J Appl Oral Sci Date: 2013 Jan-Feb Impact factor: 2.698