Zheng-yi Zhang1, Fu-cong Tian2, Li-na Niu3, Kirsten Ochala4, Chen Chen5, Bai-ping Fu1, Xiao-yan Wang2, David H Pashley4, Franklin R Tay6. 1. Department of Prosthodontics, School & Hospital of Stomatology, Zhejiang University, Hangzhou, Zhejiang, China. 2. Department of Cariology and Endodontology, School and Hospital of Stomatology, Peking University, Beijing, China. 3. State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China. Electronic address: niulina831013@126.com. 4. The Dental College of Georgia, Augusta University, Augusta, GA, USA. 5. Department of Operative Dentistry & Endodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China. 6. The Dental College of Georgia, Augusta University, Augusta, GA, USA. Electronic address: ftay@gru.edu.
Abstract
OBJECTIVES: The present study evaluated the long-term dentine bonding effectiveness of five universal adhesives in etch-and-rinse or self-etch mode after 12 months of water-ageing. METHODS: The adhesives evaluated included All-Bond Universal, Clearfil Universal Bond, Futurabond U Prime&Bond Elect and Scotchbond Universal. Microtensile bond strength and transmission electron microscopy of the resin-dentine interfaces created in human coronal dentine were examined after 24h or 12 months. RESULTS: Microtensile bond strength were significantly affected by bonding strategy (etch-and-rinse vs self-etch) and ageing (24h vs 12 months). All subgroups showed significantly decreased bond strength after ageing except for Prime&Bond Elect and Scotchbond Universal used in self-etch mode. All five adhesives employed in etch-and-rinse mode exhibited ultrastructural features characteristic of collagen degradation and resin hydrolysis. A previously-unobserved inside-out collagen degradation pattern was identified in hybrid layers created by 10-MDP containing adhesives (All-Bond Universal, Scotchbond Universal and Clearfil Universal Bond) in the etch-and-rinse mode, producing partially degraded collagen fibrils with intact periphery and a hollow core. In the self-etch mode, all adhesives except for Prime&Bond Elect exhibited degradation of the collagen fibrils along the thin hybrid layers. The three 10-MDP containing universal adhesives did not protect surface collagen fibrils from degradation when bonding was performed in the self-etch mode. CONCLUSIONS: Despite the adjunctive conclusion that bonds created by universal adhesives in the self-etch bonding mode are more resistant to decline in bond strength when compared with those bonds created using the etch-and-rinse mode, bonds created by universal adhesives are generally incapable of defying ageing.
OBJECTIVES: The present study evaluated the long-term dentine bonding effectiveness of five universal adhesives in etch-and-rinse or self-etch mode after 12 months of water-ageing. METHODS: The adhesives evaluated included All-Bond Universal, Clearfil Universal Bond, Futurabond U Prime&Bond Elect and Scotchbond Universal. Microtensile bond strength and transmission electron microscopy of the resin-dentine interfaces created in human coronal dentine were examined after 24h or 12 months. RESULTS: Microtensile bond strength were significantly affected by bonding strategy (etch-and-rinse vs self-etch) and ageing (24h vs 12 months). All subgroups showed significantly decreased bond strength after ageing except for Prime&Bond Elect and Scotchbond Universal used in self-etch mode. All five adhesives employed in etch-and-rinse mode exhibited ultrastructural features characteristic of collagen degradation and resin hydrolysis. A previously-unobserved inside-out collagen degradation pattern was identified in hybrid layers created by 10-MDP containing adhesives (All-Bond Universal, Scotchbond Universal and Clearfil Universal Bond) in the etch-and-rinse mode, producing partially degraded collagen fibrils with intact periphery and a hollow core. In the self-etch mode, all adhesives except for Prime&Bond Elect exhibited degradation of the collagen fibrils along the thin hybrid layers. The three 10-MDP containing universal adhesives did not protect surface collagen fibrils from degradation when bonding was performed in the self-etch mode. CONCLUSIONS: Despite the adjunctive conclusion that bonds created by universal adhesives in the self-etch bonding mode are more resistant to decline in bond strength when compared with those bonds created using the etch-and-rinse mode, bonds created by universal adhesives are generally incapable of defying ageing.
Authors: Wen Zhou; Xinyu Peng; Xuedong Zhou; Andrea Bonavente; Michael D Weir; Mary Anne S Melo; Satoshi Imazato; Thomas W Oates; Lei Cheng; Hockin H K Xu Journal: Int J Mol Sci Date: 2020-09-02 Impact factor: 5.923