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| Author(s): |
Rocio Geng Vivanco
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Ribeirão Preto. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Odontologia de Ribeirão Preto (PCARP/BC) |
| Defense date: | 2025-03-07 |
| Examining board members: |
Fernanda de Carvalho Panzeri;
José Roberto de Oliveira Bauer;
Ana Karina Barbieri Bedran Russo;
Francisco Wanderley Garcia de Paula e Silva
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| Advisor: | Fernanda de Carvalho Panzeri |
| Abstract | |
This in vitro study evaluated the effect of bromelain associated with Biosilicate on the bond strength (BS) of a universal adhesive system, in self-etch mode, to sound and caries-affected dentin, as well as on the proteolytic activity at the adhesive interface. Initially, the most appropriate protocol for bromelain application was determined. Afterwards, occlusal cavities were prepared in human molars. Half of the samples were subjected to cariogenic challenge. The teeth were then separated into nine groups (n = 20) according to the treatment applied before the adhesive (Single Bond Universal, 3MESPE): Control (No treatment), CHX (0.12% chlorhexidine), NaOCl (5% sodium hypochlorite), Br5% (5% bromelain), Br10% (10% bromelain), Bio (10% Biosilicate), NaOClBio (NaOCl+Bio), Br5%Bio (Br5%+Bio), Br10%Bio (Br10%+Bio). After restoration (Filtek Z350XT, 3MESPE), the samples were sectioned into sticks, which were stored in distilled water at 37 °C for 24 h, 6 months and 1 year. After these periods, they were subjected to microtensile test. Fracture patterns were observed under optical microscope, and the adhesive interface, by SEM and transmission electron microscopy. Resistance against degradation by bacterial collagenase assay and in situ zymography were performed. Data were statistically analyzed. In caries-affected dentin, after 24 h, Br10% exhibited higher BS (p < .05) than Br5%Bio and NaOClBio. Sound dentin treated with NaOCl and caries-affected dentin with Br5% showed higher BS (p < .05) after 6 months than after 24 h. Sound dentin treated with NaOClBio and caries-affected dentin with CHX, NaOCl and association of treatments had higher BS (p < .05) after 6 months and 1 year than after 24 h. Fracture patters were predominantly mixed. SEM revealed that the deproteinizing agents partially removed the smear layer, with NaOCl being the most efficient. Biosilicate particles embedded within the hybrid layer were partially dissolved after aging. The association of treatments formed a more uniform hybrid layer, with more impregnated Bio particles and, in some groups, Whitlockite crystals were exhibited. TEM showed that the deproteinizing agents promoted resin tag formation, with Br5% and Br5%Bio generating shorter tags. Bio, associated or not, showed electron-dense regions and more compact tissue. In in situ zymography, among samples without inhibitor, Control exhibited higher green fluorescence than the experimental groups (p < .05). In the resistance against degradation assay, Br5% and Br5%Bio showed lower mass loss and higher degradation than Control (p < .05). Regardless of aging and bromelain concentration, its association with Biosilicate did not impair the BS of the adhesive system, in self-etch mode, to sound dentin. In caries-affected dentin, 5% bromelain associated with Biosilicate reduced the immediate BS but had no long-term influence. When associated, aging did not impact the BS to sound dentin. In caries-affected dentin, there was an increase in BS after aging. This association reduced the activity of endogenous proteases at the adhesive interface; however, it did not prevent collagen degradation by bacterial collagenase. (AU) | |
| FAPESP's process: | 19/24922-0 - Effect of the use of Bromelain associated to bioactive glass-ceramic on dentin/adhesive interface |
| Grantee: | Rocio Geng Vivanco |
| Support Opportunities: | Scholarships in Brazil - Doctorate |