| Full text | |
| Author(s): |
Total Authors: 4
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| Affiliation: | [1] Univ Toronto, Fac Dent, Restorat Dept, Toronto, ON M5G 1G6 - Canada
[2] Univ Toronto, Fac Dent, Inst Biomat & Biomed Engn, Bone Interface Grp, Toronto, ON M5G 1G6 - Canada
[3] Univ Fortaleza, Fac Dent, Dept Dent Mat & Operat Dent, Fortaleza, Ceara - Brazil
Total Affiliations: 3
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| Document type: | Journal article |
| Source: | Dental Materials; v. 28, n. 6, p. 687-694, JUN 2012. |
| Web of Science Citations: | 27 |
| Abstract | |
Objectives. This study evaluated catechin and chlorhexidine release from copolymers based on bis-GMA diluted with TEGDMA (R1), propoxylated bis-GMA-CH(3)bis-GMA (R2) or fluorinated bis-GMA-CF(3)bis-GMA (R3). Mechanical properties, degree of conversion, water sorption and solubility were also tested. Methods. Experimental comonomers (R1, R2, R3) were prepared combining bis-GMA with the diluents (70/30 mol%). Each comonomer had either catechin or chlorhexidine incorporated in the following ratios: 0, 0.2, 1.0, 2.0 wt%. The degree of conversion (% DC) of resins was evaluated by FT-IR spectrophotometry (n = 3). Flexural strength and elastic modulus were tested on a universal testing machine at a crosshead speed of 0.5 mm/min (n = 6). Resin disks (7 mm in diameter x 2 mm high) were immersed in deionized water and mass changes recorded daily. Spectral measurements were made to follow any changes in optical densities of deionized water in order to examine catechin and chlorhexidine release rates (n = 6). After a 28-day period, water sorption and solubility were calculated using appropriate equations (n = 6). Data within the tests were evaluated by one- and three-way ANOVA and Tukey-Kramer's test (alpha = 0.05). Results. Except for R1 with 2.0% drug none of the groups had changes in degree of conversion and water sorption. Solubility increased with increased drug ratios. Changes in flexural strength and elastic modulus were shown to be variable and material-dependent. All resins presented a similar to 24 h burst of drug release. Release rates were drug-ratio dependent and significantly higher for chlorhexidine than for catechin. Significance. Monomer type, % DC, drug ratio and type lead to different interactions between resins and chlorhexidine/catechin drug particles. It should be possible to develop different resins based on clinical needs. (c) 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. (AU) | |
| FAPESP's process: | 08/06170-7 - Dentin matrix stabilization following treatment with different crosslinking agents: Effect on dentin bonding. |
| Grantee: | Renato Cilli |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |