Effects of periodontal disease on systemic bone remodeling in mice

Abstract

Periodontal disease (PD) is a chronic immune-inflammatory disease of the periodontium associated with pathogenic bacteria of the subgingival region. The pioneer approach of periodontal medicine have helped the understanding of the association between chronic periodontitis and systemic disease such diabetes, cardiovascular disease, lung infections, rheumatoid arthritis, chronic kidney disease, metabolic syndrome and preterm delivery. It is believed that the main mechanism involved in the association between PD and systemic disorders is the production of inflammatory cytokines involved in both processes. Osteoporosis is a known risk factor for PD, although the inverse interaction, in other words, the effect of PD on systemic bone remodeling is not well established and there is scarce literature about the theme though its plausible interaction. Therefore, the aim of this study is to evaluate the effect of PD on mice systemic bone loss. It will be used 40 female mice (Mus musculus, BALB/c) divided into 4 groups (n=10): 1)PD+OVX: PD (infection with Porphyromonas gingivalis) and ovariectomy; 2)PD group: PD (infection with P. gingivalis) and Sham (simulated ovariectomy); 3)OVX group: Only ovariectomy; 4) Control group: Only Sham surgery. For P.gingivalis infection we will use the method established by Baker et al. (Baker, Evans and Roopenian, 1994). At the moment of euthanasia, it will be collected 1ml of blood from abdominal aorta and then all the animals will be perfused with paraformaldehyde 4%. Maxillas and femurs will be analyzed by micro-computed tomography to evaluate bone loss and quantity/ quality of bone. Blood samples will be analyzed by ELISA to quantify serum Tumoral Necrosis Factor (TNF)-alpha, interleukin (IL)-6, interleukin (IL)-1, interleukin (IL)-17, interleukin (IL)-4, interleukin (IL)-10,Receptor activator of nuclear Kappa B ligand (RANKL),osteoprotegerin (OPG), Osteocalcin and carboxy terminal telopeptide of type I collagen. Obtained results will be submitted to exploratory analysis to determine the best statistical test to be applied. (AU)