Impact of bioactive technologies on altered dentin by erosive tooth wear or post irradiated with radiotherapy: biological assessment by in situ zymography and related physical-mechanical properties

• Grant number: 23/05793-0
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2024
• End date: March 31, 2026
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Linda Wang
• Grantee: Linda Wang
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil
• Associated researchers: Giovanna Speranza Zabeu ; Marina Ciccone Giacomini Belei ; Paulo Sérgio da Silva Santos
• Associated scholarship(s): 24/21213-7 - CARACTERIZATION OF DENTIN SURFACE AND BIOLOGICAL PROPERTIES OF ERODED DENTIN TREATED WITH BIOACTIVE AGENTS., BP.IC

Abstract

Approaches based on biotechnology have been addressed notable application prevention and resolution of dental lesions in Dentistry. With the variety of options and innovations, there is a need to further investigation regarding their effective possibilities in the most diverse clinical challenges, in which dentin is certainly one of the most affected substrates. Among the most prevalent clinical scenarios that affect dentin, erosive tooth wear (ETW) and post radiotherapy irradiated caries are conditions that require the reinforcement of dentin tissue to minimize the injuries. Products with ingredients and technologies with distinguished proposals for particular clinical situations are relevant to allow effective tissue responses. Formulations based on bioglasses or particles such as xerogel, as S-PRG technology (Giomer) are developed with the potential to induce formation of more stable compounds and reinforce the substrate trough different mechanisms. In the cases in which the adhesive products are necessary for a restorative intervention, materials based on functional monomers have shown high evidence of success in terms of bonding to the substrate. New possibilities with the simultaneous inclusion of ingredients classified as bioactive lead to adjusts that can enhance the biological potential, but can hamper the bonding property. Thus, since the main purpose of these bioactive ingredients is to induce the direct benefits to dentin, biological methods become interesting to expand the analysis of their physical-mechanical efficiency in different cases. In this scenario, the role of agents capable of inhibiting and/or controlling dentin intrinsic proteolytic enzymes, such as dentin matrix metalloproteinases (MMPs) in the process of preserving the organic matrix has produced interesting evidence, in addition to the apparent simple remineralization proposal. This study proposes to analyze essentially the biological response to the inhibition potential of MMPs with the use of different bioactive agents. Three substrates will be evaluated: sound dentin, eroded dentin and post radiotherapy irradiated dentin. Initially, pastes indicated for the control of demineralization/enhancement of remineralization will be evaluated, Biomin F (bioglass) and S-PRG 5% paste (xerogel) on these three substrates, with Colgate Total 12 being a control paste, as they can also be applied at the early state and during follow ups of other clinical conditions involving exposed dentin They will be analyzed semi-quantitetively by means of Confocal Laser Scanning Microscopy in terms of surface and longitudinally. They will also be quantitatively evaluated by this microscopy in terms of gelatinolytic activity by in situ zymography. Additional analyzes to assess the degree of wetness and microhardness of these substrates before and after treatment with these pastes will be carried out. Following, self-etching and universal self-etching adhesive systems will be compared, without or with the presence of bioactive technology. Ongoing in vitro studies have shown that systems with particles of S-PRG technology have not shown superior bonding strength. Thus, its proposal for the benefit of dentin and interface quality should be investigated. Clearfil SE Bond and FL Bond II self-etching adhesive systems will be compared with the universal systems in self-etching mode Adper Single Bond Universal and Beautibond Xtreme. Only the FL Bond II system contains this technology, but its corresponding universal version has a similar monomer base so that the analyzes can be more comparable with the 10-MDP monomer-based systems included in this study. After the protocol recommended by each manufacturer for bonding to dentin, these same 3 types of substrates will be analyzed by in situ zymography and also by viscosity, degree of wetting to integrate the ability of these systems to interact with the substrates. (AU)