Characterization of aTiO2 surfaces functionalized with CAP-p15 peptide.

Functionalization of Titanium implants using adequate organic molecules is a proposed method to accelerate the osteointegration process, which relates to topographical, chemical, mechanical, and physical features. This study aimed to assess the potential of a peptide derived from cementum attachment protein (CAP-p15) adsorbed onto aTiO2 surfaces to promote the deposition of calcium phosphate (CaP) minerals and its impact on the adhesion and viability of human periodontal ligament cells (hPDLCs). aTiO2 surfaces were synthesized by magnetron sputtering technique. The CAP-p15 peptide was physically attached to aTiO2 surfaces and characterized by atomic force microscopy, fluorescence microscopy, and water contact angle measurement. We performed in vitro calcium phosphate nucleation assays using an artificial saliva solution (pH 7.4) to simulate the oral environment. morphological and chemical characterization of the deposits were evaluated by scanning electronic microscopy (SEM) and spectroscopy molecular techniques (Raman Spectroscopy, ATR-FTIR). The aTiO2 surfaces biofunctionalized with CAP-p15 were also analyzed for hPDLCs attachment, proliferation, and in vitro scratch-healing assay. The results let us see that the homogeneous amorphous titanium oxide coating was 70 nanometers thick. The CAP-p15 (1 µg/mL) displayed the ability to adsorb onto the aTiO2 surface, increasing the roughness and maintaining the hydrophilicity of the aTiO2 surfaces. The physical adsorption of CAP-p15 onto the aTiO2 surfaces promoted the precipitation of a uniform layer of crystals with a flake-like morphology and a Ca/P ratio of 1.79. According to spectroscopy molecular analysis, these crystalline deposits correspond to carbonated hydroxyapatite. Regarding cell behavior, the biofunctionalized aTiO2 surfaces improved the adhesion of hPDLCs after 24 h of cell culture, achieving 3.4-fold when compared to pristine surfaces. Moreover, there was an increase in cell proliferation and cell migration processes. Physical adsorption of CAP-p15 onto aTiO2 surfaces enhanced the formation of carbonate hydroxyapatite crystals and promoted the proliferation and migration of human periodontal ligament-derived cells in in vitro studies. This experimental model using the novel bioactive peptide CAP-p15 could be used as an alternative to increasing the osseointegration process of implants.

Cell viability and physicochemical effects of different concentrations of bismuth trioxide in a mineral trioxide aggregate cement.

PURPOSE: To evaluate the effect of three concentrations of bismuth trioxide (Bi2O3) on the biological and physicochemical properties of an experimental mineral trioxide aggregate-type (MTA-type) cement at different time points. METHODS: Three experimental groups with white Portland cement containing 15, 20, or 25 wt% of Bi2O3 were assessed. Cellular proliferation in human periodontal ligament fibroblasts was evaluated with an MTT assay. Radiopacity, dimensional stability, pH, and compressive strength were evaluated at different time points. RESULTS: Bismuth trioxide induced cell proliferation in the Bi15 and Bi25 groups in a time-dependent manner; pH was similar in all groups. Compressive strength was associated with time and bismuth concentration. Bi25 had significantly contracted at day 7 and expanded at day 14 (ANOVA P < 0.05, post hoc Tukey test P < 0.05). CONCLUSION: A higher Bi2O3 concentration had a negative effect on the physical properties of the cement at all time points.

Mechanical Properties and Antibacterial Effect on Mono-Strain of Streptococcus mutans of Orthodontic Cements Reinforced with Chlorhexidine-Modified Nanotubes.

Recently, several studies have introduced nanotechnology into the area of dental materials with the aim of improving their properties. The objective of this study is to determine the antibacterial and mechanical properties of type I glass ionomers reinforced with halloysite nanotubes modified with 2% chlorhexidine at concentrations of 5% and 10% relative to the total weight of the powder used to construct each sample. Regarding antibacterial effect, 200 samples were established and distributed into four experimental groups and six control groups (4 +ve and 2 -ve), with 20 samples each. The mechanical properties were evaluated in 270 samples, assessing microhardness (30 samples), compressive strength (120 samples), and setting time (120 samples). The groups were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy, and the antibacterial activity of the ionomers was evaluated on Streptococcus mutans for 24 h. The control and positive control groups showed no antibacterial effect, while the experimental group with 5% concentration showed a zone of growth inhibition between 11.35 mm and 11.45 mm, and the group with 10% concentration showed a zone of growth inhibition between 12.50 mm and 13.20 mm. Statistical differences were observed between the experimental groups with 5% and 10% nanotubes. Regarding the mechanical properties, microhardness, and setting time, no statistical difference was found when compared with control groups, while compressive strength showed higher significant values, with ionomers modified with 10% concentration of nanotubes resulting in better compressive strength values. The incorporation of nanotubes at concentrations of 5% and 10% effectively inhibited the presence of S. mutans, particularly when the dose-response relationship was taken into account, with the advantage of maintaining and improving their mechanical properties.

Aqueous extract of Sedum oxypetalum induces mineralization and osteogenic differentiation by human Periodontal Ligament-Derived cells.

ETHNOPHARMACOLOGICAL RELEVANCE: The medicinal plant Sedum oxypetalum Kunth (Crassulaceae), locally known as Jiote or in general Siempreviva (always alive) has been traditionally used by people of the Mexican community of Tenango del Valle as a home remedy to treat periodontal diseases, inducing teeth strengthening. Consequently, the aim of this work was to investigate its capacity directed to mineralized tissues regeneration. MATERIALS AND METHODS: The aerial parts of the plant were processed and its aqueous extract (AE) was chemically characterized. The AE and its components sedoheptulose and syngenite were tested for either osteogenic differentiation or mineral-nucleation induction respectively. RESULTS: The AE and one of its components (sedoheptulose) were shown to promote the proliferation and/or osteogenic differentiation by Human Periodontal Ligament-Derived Cells (hPDLs), while inducing the mineralization process. The AE also promoted the nucleation of octacalcium phosphate and its component syngenite, the hydroxyapatite crystals formation in vitro. CONCLUSION: The findings reported herein support the traditional use of S. oxypetalum due to its potential capacity to promote the regeneration of mineralized tissues.