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| Author(s): |
Nádia Fayez Omar
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Piracicaba, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba |
| Defense date: | 2011-10-20 |
| Examining board members: |
Pedro Duarte Novaes;
Maria Luiza Ozores Polacow;
Elizabete Brasil dos Santos;
Silvana Pasetto;
Fernanda Klein Marcondes
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| Advisor: | Pedro Duarte Novaes |
| Abstract | |
The periodontal ligament (PL) is a tissue that occupies the space between tooth and its socket, and has main function to anchor and support the teeth. Based on published datas showing that hypofunctional teeth are more easily extracted, we investigated which one(s) factors and/or molecules could be related to the weakening of the periodontal ligament anchoring. We investigated the expression of MMPs and TIMP-2, collagen organization in the PL, and the resistance that the PL offers to the eruptive movement in rat incisors. Therefore, we altered the eruption of rat incisors, during different experimental periods, producing hypofunction, hyperfunction and restrain of the eruptive process, beyond the normal eruption, measuring the eruption rate, in all groups, throughout the experimental period. The results showed that in the hypofunctional group the MMP-2 activity and collagen disorganization increased, contributing to the decrease in the resistance strength to the eruptive movement and increased eruption rate in this group. In the restrain group, the incisor eruption was interrupted, but the MMP-2 activity increased, to varying degrees, throughout the experimental period, while the collagen organization and, thus, the resistance strength to the eruptive movement of the PL were slightly lower. On the other hand, in the hyperfunctional group the eruption rate did not change, but MMP-2 activity and PL resistance strength to eruptive movement were increased, with a slight collagen disorganization, indicating, therefore, possible changes in other molecules involved in the periodontal ligament extracellular matrix remodeling. Analyses of MT1-MMP and TIMP-2, under the conditions of this study, showed no statistical differences between groups and experimental periods. These data suggest the role of MMP-2 in periodontal ligament remodeling of rat incisors, during altered eruption, acting directly on collagen degradation, which leads to changes in PL resistance to the eruptive movement, in hypofunction condition, and MT1- MMP and TIMP-2 may have secondary participation in this process (AU) | |
| FAPESP's process: | 08/09141-8 - Relation among MMPs, TIMPs and collagen organization with periodontal ligament resistence force to eruption moviment in incisor rats |
| Grantee: | Nádia Fayez Omar |
| Support Opportunities: | Scholarships in Brazil - Doctorate |