Effects of loss of occlusal contact on the expression of matrix metalloproteinase-2, membrane type 1-MMP, tissue inhibitor of the MMP-2, eruption rate, organization and resistance of collagen fibers of the rat incisor periodontal ligament.
J Periodontal Res
; 53(1): 40-46, 2018 Feb.
Article
em En
| MEDLINE
| ID: mdl-29044524
BACKGROUND AND OBJECTIVE: This study investigated the effect of occlusal contact loss (induced by tooth shortening), on matrix metalloproteinase (MMP)-2, membrane type 1-MMP (MT1-MMP) and tissue inhibitor of the MMP-2 (TIMP-2) expressions in the periodontal ligament of the rat incisor, as well as eruption rate, resistance and collagen organization. MATERIAL AND METHODS: Male Wistar rats were distributed into a control group, denominated normofunctional group, whose lower teeth underwent a normal eruption process; and a hypofunctional group, whose lower left incisor teeth were shortened every 2 days during 14 days. Parameters were evaluated on the first, seventh and 14th days and the eruption rate was determined according to the size of the incisor during the eruption process. MMP-2 activity was determined by zymography and the expressions of the MT1-MMP and TIMP-2 proteins were quantitated by western blot. Collagen protein organization, as indicated by the birefringence of the periodontal ligament, was analyzed under polarized light and the periodontal ligament's resistance was determined from the load necessary to inject the incisor into its alveolar space, before extraction. RESULTS: Loss of occlusal contact, in rats submitted to hypofunctional eruption, increased MMP-2 activity and eruption rate, but decreased MT1-MMP and TIMP-2 expression and disrupted collagen organization in the periodontal ligament, consequently reducing periodontal ligament resistance. CONCLUSION: We conclude that, after incisor eruption, occlusal contact may be an important factor for regulating the remodeling and the physiological resistance of the periodontal ligament against the continuous eruption process observed in rat incisors.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ligamento Periodontal
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Colágeno
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Inibidor Tecidual de Metaloproteinase-2
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Metaloproteinase 2 da Matriz
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Oclusão Dentária
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Metaloproteinase 14 da Matriz
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Incisivo
Limite:
Animals
Idioma:
En
Revista:
J Periodontal Res
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos