Use of TMP on the inhibition of dentin endogen enzymes and on biomimetization of demineralized dentin substrate

• Grant number: 15/02559-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: December 01, 2015
• End date: August 03, 2017
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Linda Wang
• Grantee: Rafael Simões Gonçalves
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil
• Associated scholarship(s): 16/06869-7 - Synergy of sodium trimetaphosphate (STMP) and dentin matrix protein-1 (DMP-1) on demineralized dentin as a biomimetic strategy, BE.EP.DR

Abstract

Acids produced by cariogenic microorganisms diffuse through dental tissue causing dissolution of apatite crystals and activate endogen enzyme, which can degrade collagen. In adhesives procedures, this condition can damage the quality and durability of hybrid layer. In this way, considering a biomimetic approach, it's believed that sodium trimetaphosphate (TMP) could be an innovative strategy to stabilize and strengthen dentin by exogenous induction of collagenous cross-linking, by the interaction with the non-colagenolitics protein and through remineralization. The aim of this study will be to investigate the effect of TMP in the bovine dentin submitted to an acidic challenge with artificial caries simulation by means of biochemical and mechanical analysis. The evaluation of anti-proteolitic potential of TMP over MMP-2 and 9 will be done using zymography analisis. For this purpose, TMP solution, which concentration will be defined in the pilot study, will be added in the buffer solution and to quantify the relative inhibition of gelatinases by TMP the gels will be scanned electrophoretic band and analyzed its intensity by densitometry. For mechanical analysis, 50 bovine-root dentin specimens will be selected through Knoop values average (350KHN ±10%). After, the specimen will be divided in 3 areas: 1-control- no treatment; 2-demineralized- submitted to a demineralized solution; 3-treated- the area will be demineralized and then submitted to one of the treatment solution (TMP, TMP + NaF, TMP + Ca(OH)2, NaF, deionized H2O/negative control) and the blocks will be randomly divided in 5 groups (n=10), accordingly to treatments. All the specimens will be submitted to a pH-cycle using treatment solution (10min), demineralized solution (4h) and remineralized solution (8h). To analyze the cross-sectional hardness, the dentin blocks will be sectioned longitudinally and indentation will be performed in different deeps (10, 30, 50, 70, 90, 110 and 220µm) using a Knoop penetrator (10g/15s) in a microhardness machine. To analyze the elastic modulus dentin fragments (0.5x1.7x7.0mm) will be obtained and it will be previous demineralized in a 0.5mL phosphoric acid solution (10%/18h) and submitted to a pH-cycle as described previously and according to the treatment application. The analysis will be done using a three point flexural test with 1N load cell in a universal testing machine (0.5mm/min). The values obtained will be available according to the homogeneity to determine the statistical test that will be used (p<0.05). (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

GONCALVES, RAFAEL SIMOES; CANDIA SCAFFA, POLLIANA MENDES; GIACOMINI, MARINA CICCONE; RABELO BUZALAF, MARILIA AFONSO; HONORIO, HEITOR MARQUES; WANG, LINDA. Use of sodium trimetaphosphate in the inhibition of dentin matrix metalloproteinases and as a remineralizing agent. Journal of Dentistry, v. 68, p. 34-40, JAN 2018. (15/02559-0, 14/12316-5)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

GONÇALVES, Rafael Simões. The use of sodium trimetaphosphate for matrix metalloproteinase inhibition, remineralization and bonding to dentin. 2017. Doctoral Thesis - Universidade de São Paulo (USP). Faculdade de Odontologia de Bauru (FOB/SDB) Bauru.