A Novel Implant's Surface Functionalized by DPP and its Impact on Peri-implant Repair in Osteoporotic Rats

• Grant number: 25/09595-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: October 01, 2025
• End date: February 28, 2027
• Field of knowledge: Health Sciences - Dentistry - Oral and Maxillofacial Surgery
• Principal Investigator: Roberta Okamoto
• Grantee: Odir Nunes de Oliveira Filho
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil
• Associated scholarship(s): 25/25344-1 - Nanoindentation Characterization of Peri-implant Bone Response to DPP-Functionalized Implants in Osteoporotic Rats, BE.EP.MS

Abstract

The surface of a dental implant is crucial for osseointegration, and its functionalization with locally acting substances can optimize bone repair, particularly in patients with systemic conditions such as osteoporosis. The use of local therapeutics that act synergistically with the patient's systemic medication may further promote bone remodeling and improve clinical outcomes. Dentin Phosphophoryn (DPP) is a non-collagenous protein from the SIBLING family, primarily found in dentin and to a lesser extent in bone. Highly phosphorylated, it has a strong affinity for calcium and is essential for biomineralization. This project aims to evaluate the effects of implant surface functionalization with DPP in healthy or osteoporotic rats. In the first stage, implant functionalization and surface characterization will be performed using SEM and UV-Vis spectroscopy. In the second stage, the in vivo experiment will be conducted; for this, 32 rats will be divided into two main groups: SHAM (sham surgery) and OVX (bilateral ovariectomy). Within each experimental group, there will be two subgroups according to the type of implant surface treatment: CONV (conventional implants, without surface functionalization) and DPP (implants functionalized with DPP using LbL technique). The animals will receive the implants 90 days after SHAM or OVX surgery. Each animal will receive two implants, one in each proximal tibial metaphysis, bilaterally. Euthanasia will be performed 28 days after implant placement. The collected tibiae will be used for biomechanical analysis (removal torque), molecular analysis (real-time PCR - expression of Bglap (OCN), ALP, Wnt3a, Ibsp, Runx2, Acp5 (Trap), Vegfa, Arginase 1, and Col1a1), three-dimensional microtomography (microCT), laser confocal microscopy (bone dynamics through fluorochrome-labeled areas of calcein and alizarin red precipitation), and immunohistochemistry of proteins involved in the bone remodeling process (Bglap (OCN), ALP, Wnt3a, Ibsp, Runx2, Acp5 (Trap), Vegfa, Arginase 1, and Col1a1). Quantitative data will be tested for normality to determine the appropriate use of parametric or non-parametric statistical methods, considering a significance level of 5%. Complementary cell culture analyses will be proposed through the BEPE program, in collaboration with Professor Anne George at the University of Illinois at Chicago (UIC).