Nanoindentation Characterization of Peri-implant Bone Response to DPP-Functionalized Implants in Osteoporotic Rats

• Grant number: 25/25344-1
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: April 01, 2026
• End date: July 31, 2026
• Field of knowledge: Health Sciences - Dentistry - Oral and Maxillofacial Surgery
• Principal Investigator: Roberta Okamoto
• Grantee: Odir Nunes de Oliveira Filho
• Supervisor: Anne George
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil
• Institution abroad: University of Illinois at Chicago (UIC), United States
• Associated to the scholarship: 25/09595-4 - A Novel Implant's Surface Functionalized by DPP and its Impact on Peri-implant Repair in Osteoporotic Rats, BP.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 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 BEPE project aims to evaluate the reduced elastic modulus (Er) and nanohardness (H) of trabecular bone by nanoindentation using a TI 700 Ubi NanoIndenter, in order to assess the effects of implant's surface functionalization with DPP in healthy and osteoporotic rats. The implant functionalization and surface characterization steps are being carried out as part of the current Master's scholarship in Brazil. The in vivo experimentation is also being carried out, involving two main groups: SHAM (sham-operated) and OVX (bilaterally ovariectomized). Within each experimental group, there are 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 rats received the implants 90 days after SHAM or OVX surgery. Each animal received two implants, one in each proximal tibial metaphysis. Euthanasia will be performed 28 days after implant placement. In the current Master's scholarship, the collected tibiae will be used for biomechanical analysis (removal torque), molecular analysis (real-time PCR), three-dimensional microtomography (micro-CT), laser confocal microscopy (bone dynamics), and immunohistochemistry. In this BEPE proposal we aim to better characterize the biomechanical peri-implant trabecular bone with reduced elastic modulus and nanohardness, which will provide meaningful insights into the effect of DPP functionalized implants in bone quality. 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%. (AU)