| Full text | |
| Author(s): |
do Espírito Santo‚ A.R.
;
Frozoni‚ M.R.S.
;
Ramos-Perez‚ F.M.M.
;
Novaes‚ P.D.
;
Line‚ S.R.P.
Total Authors: 5
|
| Document type: | Journal article |
| Source: | Connective Tissue Research; v. 51, n. 3, p. 208-215, 2010. |
| Abstract | |
The aim of the present study was to assess birefringence of the secretory-stage enamel organic extracellular matrix (ECM) and mechanical properties of mature enamel from rats treated with bisphosphonates. Longitudinal sections were obtained from upper incisors of rats that had been submitted to injections of bisodic etidronate (8 mg/Kg/day), sodium alendronate (30 mu g/Kg/day), or sodium chloride as control (8 mg/Kg/day) for 42 days. Sections were immersed in 80% glycerin for 30 min and optical retardation of birefringence brightness in the secretory-stage enamel organic ECM was determined in nanometers. Etidronate-treated rats exhibited extensive morphological changes in the secretory-stage enamel organic ECM inclusive nonbirefringent conspicuous incremental lines, but presented optical retardation values similar to those showed by control rats (p > 0.05). Birefringence of secretory enamel organic ECM from etidronate rats presented an irregular aspect. Alendronate-treated rats did not show morphological alterations in the secretory-stage enamel organic ECM, however, they presented significant reduction in optical retardation of birefringence brightness when compared with control and etidronate rats (p < 0.01). Alendronate and etidronate groups exhibited reductions of approximate to 6-10% in mature enamel cross-sectional microhardness when compared with control group (p < 0.01). Scanning electron microscopy analysis showed extensive alterations in mature enamel only from etidronate group with absence of enamel rods. The present work shows that bisphosphonates can affect the birefringence of the secretory-stage enamel organic ECM. The results presented here suggest that alterations in the supramolecular organization of the secretory-stage enamel organic ECM are a plausible mechanism by which environmental factors may cause enamel defects. (AU) | |
| FAPESP's process: | 04/13255-8 - Effects of genetic and environmental alterations on the birefringence of dental enamel organic matrix |
| Grantee: | Alexandre Ribeiro do Espírito Santo |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 04/10994-4 - Defects in the formation of the dental organ |
| Grantee: | Sergio Roberto Peres Line |
| Support Opportunities: | Research Projects - Thematic Grants |