Periimplant bone repair in type 2 diabetics rats treated with the combination of antimicrobial photodynamic therapy and polyphenol compounds. Biomechanical, histometric, microtomographic and molecular characterization

Author(s)

Letícia Pitol Palin

• Document type: Master's Dissertation
• Press: Araçatuba. 2021-02-19.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araçatuba
• Defense date: 2021-02-17
• Advisor: Roberta Okamoto; Letícia Helena Theodoro

Abstract

The aim of this study is to characterize bone tissue repair responses after the installation of implants in type 2 diabetic rats treated systemically with resveratrol and with local use of aPDT, through biomechanical and molecular analysis. One hundred and twenty-eight rats were used, divided into four groups: 1- NG: normoglycemic rats; 2- NGrvt: normoglycemic rats treated with oral resveratrol; 3- T2D: type 2 diabetic rats; and 4- T2Drvt: type 2 diabetic rats treated with oral resveratrol. Within each group, are four subgroups: ST- No local therapy (n=8), the surgical store received no additional local therapy; MB- Methylene blue (n=8), topical application of methylene blue for 60 seconds; FBM- Photobiomodulation (n=8), low intensity laser irradiation for 60 seconds; aPDT- Antimicrobial photodynamic therapy (n=8), association of methylene blue application with low intensity laser irradiation. T2D induction was made by the association of cafeteria diet with a single application of Streptozotocin (35mg.kg). After type 2 diabetes confirmation, resveratrol treatment was started and after two weeks the animals were submitted to upper first molars extraction and implants installation. At this moment the local therapies were performed according to the groups. After 28 days, the animals were euthanized and the biomechanical (removal torque) and molecular analysis of RT-PCR (IBSP, OCN, TRAP OPG and RANK-L) were performed. The quantitative data were submitted to the Shapiro Wilk normality test to confirm the normal distribution of the samples. In the sequence, the ANOVA tests were applied one or two factors, followed by Tukey's post-test, with a significance level of 5%. The results of biomechanical analysis showed that in normoglycemic animals treated or not by resveratrol had a decrease in the implants removal torque when local therapies were applied. The presence of systemic interference and the use of local therapies helped to increase biomechanical values, especially in the T2Drvt group with the use of aPDT. The molecular analysis of RT-PCT at 28 days suggests that in the NG group the expression of IBSP was similar with the presence or not of local therapies, however there was a decrease in OCN genes and an increase in TRAP with the use of therapies. In NGrvt, there was an increase in IBSP expression in the absence of local therapies, a decrease in OCN and TRAP when using therapies and a significant increase in OPG without RANK-L with the systemic use of resveratrol without local treatments. T2D group expressed an increase of IBSP with the use of PBM therapy, aPDT raised the expression of OCN and decreased TRAP and RANK-L. The use of resveratrol on T2Drvt and its association with aPDT increased the expression of IBSP and OCN, and also decreased TRAP and RANK-L expression. The overall analysis of the results allows us to conclude that the systemic use of resveratrol and its association with aPDT promoted an improvement in periimplant repair of type 2 diabetic rats, increasing the expression of genes related to bone matrix mineralization and decreasing the expression of genes related to bone resorption that resulted in an improvement of bone biomechanics. (AU)

• FAPESP's process: 19/01634-0 - Perimplantar repair in rats type 2 diabetics treated with the combination of antimicrobial photodynamic therapy and polyphenol compounds: biomechanical, histometric, microtomographic and molecular characterization
• Grantee: Letícia Pitol Palin
• Support Opportunities: Scholarships in Brazil - Master