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Objective Formulate experimental adhesives containing titanium dioxide nanotubes (nt-TiO2) or titanium dioxide nanotubes with a triazine-methacrylate monomer (nt-TiO2:TAT) and evaluate the effect of these fillers on the physical, chemical, and biological properties of the adhesives. Methods First, nt-TiO2 were synthesized via a hydrothermal method. The nt-TiO2 were mixed with a triazine-methacrylate monomer (TAT) to formulate nt-TiO2:TAT, which were characterized by transmission electron microscopy (TEM). The nt-TiO2, TAT, and nt-TiO2:TAT were evaluated via Fourier Transform Infrared, Ultraviolet–visible, and micro-Raman spectroscopies. An experimental adhesive resin was formulated with bisphenol A glycerolate dimethacrylates, 2-hydroxyethyl methacrylate, and photoinitiator/co-initiator system. nt-TiO2 or nt-TiO2:TAT were incorporated at 2.5 wt.% and 5 wt.% in the adhesive. The base resin without nt-TiO2 or nt-TiO2:TAT was used as a control group. The adhesives were evaluated for antibacterial activity, cytotoxicity, polymerization kinetics, degree of conversion (DC), Knoop hardness, softening in solvent (ΔKHN%), ultimate tensile strength (UTS), 24 h- and 1 year- microtensile bond strength (μ-TBS). Results TEM confirmed the nanotubular morphology of TiO2. FTIR, UV–vis, and micro-Raman analyses showed the characteristic peaks of each material, indicating the impregnation of TAT in the nt-TiO2. Adhesives with nt-TiO2:TAT showed antimicrobial activity against biofilm formation compared to control (p 0.05). All groups showed high percentages of pulp cell viability. The polymerization kinetics varied among groups, but all presented DC above 50%. The addition of 5 wt.% of nt-TiO2 and both groups containing nt-TiO2:TAT showed higher values ​​of Knoop hardness compared to the control (p Significance The mixing of a triazine-methacrylate monomer with the nt-TiO2 generated a filler that improved the physicochemical properties of the adhesive resins and provided antibacterial activity, which could assist in preventing carious lesions around tooth-resin interfaces. The set of physical, chemical, and biological properties of the formulated polymer, together with the greater stability of the bond strength over time, make nt-TiO2:TAT a promising filler for dental adhesive resins.

Objective The aim of this study was to incorporate sol–gel-derived bioactive glass as filler into experimental adhesive resins and evaluate the influence of glass composition on the physicochemical and biological properties of the developed adhesives. Materials and methods Sol–gel particles were produced with or without the addition of niobium (BAGNb or BAG, respectively). The produced particles were incorporated (2 wt%) into experimental adhesive resins formulated with 66 wt% bisphenol A-glycidyl methacrylate and 33 wt% hydroxyethyl methacrylate. Ethyl dimethyl-4-aminobenzoate and camphorquinone were used as photoinitiator system. Two experimental groups were produced: ABAGNb and ABAG. The adhesive without particles was used as control (ACG). The materials were tested for their degree of conversion, softening in solvent, and cytotoxicity. The mineral deposition was analyzed by Raman spectroscopy. Flexural strength and immediate and 1-year microtensile bond strength were evaluated. Results No statistical difference was found in degree of conversion. ABAGNb showed reduced softening and higher mineral deposition than ACG and ABAG after 28 days. ABAG and ABAGNb resulted in higher cell viability and lower flexural strength when compared to ACG. After 1-year, ABAGNb and ABAG presented statistically significant lower μTBS values. Significance Sol–gel-derived bioactive glasses promoted increased mineral deposition and cell viability for experimental adhesives with increased phosphate content and longitudinal μTBS values for the ABAGNb group. These results suggest the potential of the studied particles to be applied as bioactive fillers for dental adhesives. Reductions in longitudinal μTBS and flexural strength, however, were observed for both glasses compositions and must be considered.

The aim of this study was to evaluate physicochemical properties, long-term microtensile bond strength and cytotoxicity of methacrylate-based adhesive containing boron nitride nanotubes (BNNTs) as fillers.A dental adhesive was formulated using BisGMA/HEMA, 66/33wt% (control). Inorganic BNNT fillers were incorporated into the adhesive at different concentrations (0.05, 0.075, 0.1 and 0.15wt%). Analyses of degree of conversion (DC), polymerization rate [Rp.(sDC and max. polymerization rate increased (p0.05) after incorporating 0.075 and 0.1wt% BNNT. The contact angle on dentin increased (p0.05) after incorporating 0.15wt% BNNT. The μTBS-24h showed no changes (p0.05) after incorporating up to 0.15wt% BNNT comparing to control. After 6 months, μTBS decreased (p0.05) for control and 0.15wt% BNNT and BNNT groups up to 0.15wt% showed higher μTBS than control (p0.05). No difference of fibroblast growth was found among adhesives (p0.05) and up to 19% of cell viability was found comparing 0.05wt% BNNT to positive control group (100%).Incorporating boron nitride nanotubes up to 0.1wt% into dental adhesive increased the long-term stability to dentin without decreasing viability of fibroblast cell growth. Thus, the use of BNNTs as filler may decrease failure rate of current dentinal adhesives.

Objective To incorporate indomethacin and triclosan-loaded nanocapsules into primer and adhesive, and evaluate its properties. Methods Indomethacin and triclosan were encapsulated by deposition of preformed polymer and subsequently characterized regarding morphology, particle size, drug content and cytotoxicity. Nanocapsules (NCs) were incorporated into primer at 2% and into adhesive at 1, 2, 5, and 10% concentrations. Degree of conversion (DC) and softening in ethanol of the adhesive were evaluated. Drug release and drug diffusion through dentin was quantified by high performance liquid chromatography. Antimicrobial test was performed until 96 h. Results Spherical and biocompatible NCs presented mean size of 159 nm. Drugs content was 3 mg indomethacin/g powder and 2 mg triclosan/g powder. Incorporating NCs in adhesive showed no influence in DC (p = 0.335). The addition of 2% of NCs showed no influence in softening in ethanol (p > 0.05). After 120 h, 93% of indomethacin and 80% of triclosan were released from primer, 20% of indomethacin and 17% of triclosan were released from adhesive with 10% of NCs. Indomethacin showed diffusion through dentin. In 24 h, adhesive containing 2 and 5% of NCs using primer with NCs showed antimicrobial effect. In 96 h, adhesives containing different concentration of NCs promoted antimicrobial effect. Conclusions Indomethacin and triclosan-loaded nanocapsules were successfully incorporated into primer and adhesive, promoting controlled drugs release, indomethacin diffusion through dentin and antimicrobial effect without compromising its physicochemical properties. Significance Indomethacin and triclosan-loaded nanocapsules have potential to prevent recurrent caries and to be used in deep cavities controlling pulpar inflammatory process.

The purpose of this study was to evaluate the reactivity and polymerization kinetics behavior of a model dental adhesive resin with water-soluble initiator systems.A monomer blend based on Bis-GMA, TEGDMA and HEMA was used as a model dental adhesive resin, which was polymerized using a thioxanthone type (QTX) as a photoinitiator. Binary and ternary photoinitiator systems were formulated using 1mol% of each initiator. The co-initiators used in this study were ethyl 4-dimethylaminobenzoate (EDAB), diphenyliodonium hexafluorophosphate (DPIHFP), 1,3-diethyl-2-thiobarbituric acid (BARB), p-toluenesulfinic acid and sodium salt hydrate (SULF). Absorption spectra of the initiators were measured using a UV-Vis spectrophotometer, and the photon absorption energy (PAE) was calculated. The binary system camphorquinone (CQ)/amine was used as a reference group (control). Twelve groups were tested in triplicate. Fourier-transform infrared spectroscopy (FTIR) was used to investigate the polymerization reaction during the photoactivation period to obtain the degree of conversion (DC) and maximum polymerization rate (R(p)(max)) profile of the model resin.In the analyzed absorption profiles, the absorption spectrum of QTX is almost entirely localized in the UV region, whereas that of CQ is in the visible range. With respect to binary systems, CQ+EDAB exhibited higher DC and R(p)(max) values. In formulations that contained ternary initiator systems, the group CQ+QTX+EDAB was the only one of the investigated experimental groups that exhibited an R(p)(max) value greater than that of CQ+EDAB. The groups QTX+EDAB+DPIHFP and QTX+DPIHFP+SULF exhibited values similar to those of CQ+EDAB with respect to the final DC; however, they also exhibited lower reactivity.Water-soluble initiator systems should be considered as alternatives to the widely used CQ/amine system in dentin adhesive formulations.