Biomechanical and immunohistochemical aspects of bones affected by osteopenia and submitted to tibial implants

• Grant number: 19/22506-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2020
• End date: January 31, 2021
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Vinícius Pedrazzi
• Grantee: Flavia Maria Ferreira Paro
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Dental loss is very common, resulting from trauma or bone disease. The restoration of the dental organ through implants has long been explored in the literature, but the great challenge of this type of clinical approach is its indication in bones affected by osteoporosis. Aiming at the treatment and prevention of bone fractures in osteoporotic bones, since the 70's the first choice drugs administered to patients are bisphosphonates. The beneficial effects of alendronate have been known for decades and the primary action of alendronate is inhibition of osteoclasts. However, the use of alendronate reduces bone turnover markers, and since 2003 some cases of patients exposed to bisphosphonates have been reported. the presence of mandibular osteonecrosis. Thus, we believe that the use of doxycycline in subantimicrobial doses (Non-antimicrobial dose or Subantimicrobial dose doxycycline - SDD) may present a better prognostic alternative in bones affected by osteoporosis with an indication for implants. The aim of this project is to evaluate and compare the effect of the drug doxycycline, at a subantimicrobial dose (SDD) of 30 mg/kg/day, with alendronate sodium, the standard drug, on bone remodeling that occurs in osteopenic rats after treatment. with implants, as well as their action potential in the physiological bone trabeculate. Forty-two Wistar rats will be randomly divided into 6 groups of 7 rats each. The groups will be defined as follows: C - Control; CDOX - Control exposed to doxycycline 30 mg/kg/day; CAL - Control exposed to alendronate sodium 0.7 mg/kg/week; OVX - Ovariectomized Control; OVXDOX - Ovariectomized exposed to doxycycline 30mg/kg/day; OVXAL - Ovariectomized exposed to alendronate sodium 0.7mg/kg/week. The experimental procedures of the groups will begin at 80 days of age since females reach sexual maturity at this age and it is known that bone maturity is acquired only at 10 months of age (or 300 days of life). rats will undergo osteopenia/osteoporosis induction for 90 days. Thereafter, 60-day drug treatment with Doxycycline at a concentration of 30mg/kg/day and sodium alendronate at a concentration of 0.7mg/kg/week will be initiated. the groups exposed to the drug. After the 30-day drug treatment period, the rats will receive the implants. After 60 days of drug treatment, normal anesthetic death will be induced followed by gradual inhalation of CO2. Verifying the normality of the data, they will be submitted to parametric tests and if they are not normal, they will be submitted to non-parametric tests. The statistical test will be performed with the SPSS 11 program under the linear, multivariate model. And the results will be disseminated as scientific articles.