Development and characterization of an adhesive system with the addition of curcumin anchored to nanoslica in the dentin/composite bond strength

Author(s)

Júlia Correa Raffaini

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Ribeirão Preto (PCARP/BC)
• Defense date: 2024-05-10

Examining board members

Fernanda de Carvalho Panzeri; Vicente Castelo Branco Leitune; Washington Luiz Esteves Magalhães; Ana Beatriz Silva Sousa

• Advisor: Fernanda de Carvalho Panzeri

Abstract

This study aimed to evaluate the efficiency of incorporating curcumin nanoparticles (CUN) anchored to nanosilica in an experimental adhesive system to characterize the mechanical and antimicrobial properties of the proposed adhesive protocols, as well as to evaluate bond strength (BS) to dentin, morphological characteristics of the adhesive interface, and mass variation after dentin biomodification. The first stage of the study aimed to determine the most efficient concentrations of curcumin. Thus, an experimental adhesive system (Exp) containing curcumin anchored to nanosilica at concentrations of 0%, 1%, 2.5%, and 5% was tested. Flexural strength and the antimicrobial potential of the adhesive were evaluated. The results were analyzed (One-way ANOVA, Tukey, p<0.05), leading to the selection of two appropriate curcumin concentrations for evaluating bond strength (BS). For this test, healthy human molars were selected, and class I occlusal cavities (6 x 7 x 4 mm) were prepared using tungsten carbide burs. Half of the teeth were subjected to caries formation using the microbiological method with S. mutans ATCC25175 standard strain. Subsequently, the teeth were separated into groups according to the adhesive protocols to which they were subjected: Control - Commercial adhesive (Single Bond Universal - 3M ESPE); CAN 0% Group - Exp without curcumin; CAN 1% Group - Exp + 1% CUN concentration; CAN 2.5% Group - Exp + 2.5% CUN concentration. After restoration with composite resin (Filtek Z350, 3M ESPE), all samples were sectioned into stick-shaped specimens (0,81mm2), separated, and stored in distilled water at 37°C for 24 hours and for 6 months. After these periods, they were subjected to microtensile bond strength test (OM100, Odeme) at a speed of 0.5 mm/min. The data were analyzed (3-way ANOVA, Bonferroni p < 0.05), fracture patterns were observed under an optical microscope (VHM100 Keyence Brasil), and scanning electron microscopy (JSM 5410, Sony) was performed. The mass loss after the use of adhesives for dentin biostability analysis was also assessed (One-way ANOVA, Tukey, p<0.05). The addition of curcumin anchored to nanosilica to Exp resulted in greater antimicrobial properties than the commercial adhesive (p < 0.5), regardless of the tested curcumin concentration. CAN 1% resulted in lower BS on carious substrate after 24 hours of application, unlike the commercial adhesive (p < .05). Aging of the samples was only significant for healthy substrate in the CAN 1% group. The dentin adhesive did not lose efficiency on carious substrate after aging, regardless of the tested group. SEM images demonstrate that the use of all Exp resulted in the formation of Whitlockite crystals in carious dentin after 6 months of application. Mass loss after treatments with experimental adhesives was greater than for the commercial adhesive (p < .05), regardless of the added curcumin concentration. The most prevalent fracture patterns were adhesive and mixed. It is concluded that adhesives containing curcumin demonstrated superior antimicrobial potential compared to the commercial adhesive, besides showing no differences in mechanical properties among the groups. Curcumin at 1% was less effective in adhering to carious substrates compared to the commercial adhesive. Aging only impacted the sound substrate in the 1% curcumin group, while the dentin adhesive maintained its effectiveness on carious substrates, regardless of aging. (AU)

• FAPESP's process: 22/11549-2 - DEVELOPMENT AND CHARACTERIZATION OF AN ADHESIVE SYSTEM WITH ADDITION OF CURCUMIN ANCHORED TO NANOSILLIC ON DENTIN/COMPOSITE BOND STRENGTH.
• Grantee: Júlia Correa Raffaini
• Support Opportunities: Scholarships in Brazil - Master