Radiotherapy Activates Matrix Metalloproteinases in the Dentinoenamel Junction of Primary Teeth

Author(s)

Queiroz, Alexandra M. ^[1] ; Carpio-Bonilla, Claudia M. ^[1] ; Arnez, Maya F. M. ^[1] ; dos Santos, Thais T. ^[1] ; Palma-Dibb, Regina G. ^[2] ; Oliveira, Harley F. ^{[3, 4]} ; Nelson-Filho, Paulo ^[1] ; Silva, Lea A. B. ^[1] ; Paula-Silva, Francisco W. G. ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Dent Ribeirao Preto, Dept Pediat Clin, Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Sch Dent Ribeirao Preto, Dept Restorat Dent, Ribeirao Preto, SP - Brazil

^[3] Marcio Cunha Hosp, Ipatinga, MG - Brazil

^[4] Radiooncol Treatment Ctr, Ribeirao Preto - Brazil

• Document type: Journal article
• Source: JOURNAL OF DENTISTRY FOR CHILDREN; v. 87, n. 2, p. 83-89, MAY 2020.
• Web of Science Citations: 0

Abstract

Purpose: Radiation-related caries is characterized by enamel delamination near the dentinoenamel junction (DEJ). We investigated the activity and expression of the matrix metalloproteinases (MMPs) -2 and -9 in order to understand disease pathogenesis in teeth submitted or not to radiotherapy (RT). Methods: In situ zymography and immunofluorescence assays were performed to evaluate the activity and expression of MMPs -2 and -9, respectively. Twelve primary second molars were randomly assigned into two experimental subgroups: irradiated and nonirradiated. Dental fragments were exposed to radiation at a dose fraction of two Gy for five consecutive days until reaching the total dose of 60 Gy. The per-centage of fluorescence in the DEJ was evaluated in three distinct regions of the tooth (cervical, cusp, and pit). The regions were photographed under fluorescence microscopy at 1.25x and 5x magnification. Results: The intensity of fluorescence per mm(2) in the DEJ was higher in the cervical region of irradiated primary teeth (P<0.05) versus nonirradiated ones. In these areas, immunofluorescence revealed expression of MMPs -2 and -9. Conclusion: Radiotherapy can increase the activity of MMPs -2 and -9 in the cervical region of the DEJ of primary teeth. (AU)

• FAPESP's process: 16/16243-8 - Influence of radiation on color change of binomial enamel / composite restoration
• Grantee: Thais Tedeschi dos Santos
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 10/17611-4 - Mechanisms involved in the regulation of 5-lipoxygenase pathway in experimentally-induced apical periodontitis
• Grantee: Francisco Wanderley Garcia de Paula e Silva
• Support Opportunities: Research Grants - Young Investigators Grants