| Autor: |
Akiya S; Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University., Sato K; Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University., Kibe K; Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University., Tichy A; Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.; Institute of Dental Medicine, First Faculty of Medicine of the Charles University and General University Hospital in Prague., Hiraishi N; Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University., Prasansuttiporn T; Department of Restorative Dentistry and Periodontology, Faculty of Dentistry, Chiang Mai University., Hosaka K; Department of Regenerative Dental Medicine, Tokushima University.; Institute of Global Affairs, Tokyo Medical and Dental University., Foxton RM; Institute of Global Affairs, Tokyo Medical and Dental University.; Center for Dental Education, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London., Shimada Y; Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University., Nakajima M; Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.; Department of Regenerative Dental Medicine, Tokushima University. |
| Abstrakt: |
Volumetric shrinkage (VS) of conventional, bulk-fill, and core build-up resin-based composites (RBCs) of various thickness (1-5 mm) was measured using the modified bonded-disk method with confocal laser scanning microscopy. Additionally, the bottom-to-top ratio of Vickers hardness (%VH) was measured. Conventional RBCs exhibited significantly higher VS than bulk-fill and core build-up RBCs (p<0.05). As specimen thickness increased, VS relative to volume (%VS) and difference in VS at each depth (VS depth ) decreased. For conventional RBCs, there was a significant drop in VS depth between 1 mm and 2 mm (p<0.05), and another drop was observed between 3 mm and 4 mm (p<0.05) where %VH decreased below 90%. For bulk-fill and core build-up RBCs, VS depth decreased significantly between 2 mm and 3 mm (p<0.05), but %VH exceeded 90% even in 5 mm deep cavities. These results indicated that post-curing contributed to lower shrinkage in deeper layers, and that conventional RBCs were not adequately polymerized at the depth of over 3 mm. |
