RESUMO
OBJECTIVES: This study aims to evaluate the effect of non-thermal plasma (NTP) surface treatment in two composite inorganic fillers and evaluate their impact on the chemical-mechanical properties and bond strength ability of experimental resin cements. MATERIALS AND METHODS: Ytterbium fluoride (YF) and barium silicate glass (BS) were characterized and submitted to different surface treatments: non-thermal plasma (NTP); non-thermal plasma and 3-(trimethoxysilyl) propyl methacrylate silanization; and 3-(trimethoxysilyl) propyl methacrylate silanization. Untreated fillers were used as a control. The fillers were incorporated at 65wt% concentration into light-cured experimental resin cements (50wt% BisGMA; 25wt% UDMA; 25wt% TEGDMA; 1mol% CQ). The degree of conversion, the flexural strength, and the microshear bond strength (µSBS) were evaluated to characterize developed composites. RESULTS: YF and BS were successfully cleaned with NTP treatment. Nor NTP neither the silanization affected the degree of conversion of resin cements. The NTP predicted an increase in YF-containing resin cements flexural strength, reducing the storage impact in these materials. NTP treatment did not affect the µSBS when applied to YF, while silanization was effective for BS-containing materials. CONCLUSION: NTP treatment of inorganic particles was possible and was shown to reduce the amount of organic contamination of the particle surface. YF surface treatment with NTP can be an alternative to improve the organic/inorganic interaction in resin composites to obtain materials with better mechanical properties. CLINICAL RELEVANCE: Surface cleaning with NTP may be an alternative for particle surface cleaning to enhance organic-inorganic interaction in dental composites resulting in improved mechanical strength of experimental resin cements.
Assuntos
Colagem Dentária , Gases em Plasma , Bis-Fenol A-Glicidil Metacrilato/química , Resinas Compostas/química , Teste de Materiais , Cimentos de Resina/química , Silanos/química , Propriedades de SuperfícieRESUMO
The aim of the present study was to formulate dental adhesives with different concentrations of LiNbO3 and to evaluate their physicochemical and antibacterial properties. A dental adhesive was formulated using methacrylate monomers and photoinitiators and used as a control filler-free group. Subsequently, three experimental adhesives doped with LiNbO3 at different concentrations (1 wt.%, 2 wt.%, and 5 wt.%) were also formulated. All the experimental adhesives were assessed to evaluate the degree of conversion (DC), softening in solvent, immediate and long-term microtensile bond-strength (µ-TBS), radiopacity, ultimate tensile strength, and antibacterial activity. The incorporation of 1 wt.% of LiNbO3 had no negative effect on the DC of the adhesive resin compared to the control group (p > 0.05). We observed a decrease in the percentage of softening in solvent in the group LiNbO3 at 1 wt.% (p < 0.05). The addition of LiNbO3 increased the radiopacity at a concentration above 2 wt.%, and there was also an increase in cohesive strength (p < 0.05). The immediate µ-TBS increased for LiNbO3 at 5 wt.% (p < 0.05), and there was no statistical difference for the other groups compared to the control (p > 0.05). After six months, the group with 5 wt.% still presented the highest µ-TBS (p < 0.05). The adhesives showed no antimicrobial activity (p > 0.05). LiNbO3 was successfully incorporated in dental adhesives, increasing the radiopacity and their resistance to degradation. Although LiNbO3 offered no antibacterial properties, the reliability of LiNbO3 incorporation in the adhesive encourages new tests to better investigate the antimicrobial action of LiNbO3 through temperature variation.