Hydroxyapatite (HAp) is a ceramic material composing the inorganic portion of bones. Ionic substitutions enhance characteristics of HAp, for example, calcium ions (Ca²⁺) by cerium ions (Ce³⁺). The use of HAp is potentialized through biopolymers, cashew gum (CG), and gellan gum (GG), since CG/GG is structuring agents in the modeling of structured biocomposites, scaffolds. Ce-HApCG biocomposite was synthesized using a chemical precipitation method. The obtained material was frozen (–20 °C for 24 h), and then vacuum dried for 24 h. The Ce-HApCG was characterized by X-Ray diffractograms (XRD), X-ray photoemission spectra (XPS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy (EDS). XRD and FTIR showed that Ce-HApCG was successfully synthesized. XRD showed characteristic peaks at 2θ = 25.87 and 32.05, corresponding to the crystalline planes (0 0 2) and (2 1 1), respectively, while phosphate bands were present at 1050 cm⁻¹ and 1098 cm⁻¹, indicating the success of composite synthesis. FESEM showed pores and incorporated nanostructured granules of Ce-HApCG. The mechanical test identified that Ce-HApCG has a compressive strength similar to the cancellous bone’s strength and some allografts used in surgical procedures. In vitro tests (MTT assay and hemolysis) showed that scaffold was non-toxic and exhibited low hemolytic activity. Thus, the Ce-HApCG has potential for application in bone tissue engineering.

Background: High-fluoride dentifrice is used to manage root caries, but there is no evidence whether its association with nanohydroxyapatite could provide an additional protection for root caries. Therefore, this study aimed to develop and evaluate the effect of an experimental dentifrice with high fluoride (F⁻) concentration and nanohydroxyapatite (nano-HA) on root dentin demineralization. Materials and Methods: After formulation of dentifrices, root dentin specimens were randomly assigned to six groups (n = 10) using different dentifrice treatments: placebo; nano-HA without F⁻; 1,100 μg F⁻/g; 1,100 μg F⁻/g + nano-HA; 5,000 μg F⁻/g; and 5,000 μg F⁻/g + nano-HA. A pH cycling model was performed for 10 days, in which treatments were performed twice a day. After that period, the longitudinal hardness was evaluated and the area of demineralization (ΔS) was calculated. The formulated dentifrices were evaluated for primary stability, cytotoxicity, and other technical parameters. Two-way ANOVA and Tukey’s test with p set at 5% were used for data analysis. Results: The experimental dentifrices were stable and had no cytotoxicity. Regarding dentin demineralization, the placebo group significantly increased ΔS compared to all other treatment groups (p< 0.001). The dentifrices containing 5,000 μg F⁻/g, regardless of the presence of nano-HA, led to a smaller lesion area in relation to the other treatments (p< 0.001). Conclusion: The findings of this study suggest that nano-HA reduced dentin demineralization, and dentifrice with 5,000 μg F⁻/g dentifrices, regardless of the presence of nano-HA, showed a greater reduction in root dentin demineralization.

Os fosfatos de cálcio são materiais cerâmicos que apresentam propriedades particulares como biocompatibilidade e similaridade química com os tecidos ósseos e dentários dos seres vivos. Sua morfologia porosa permite que estes se apresentem como material apropriado para a utilização em substituição de pequenas partes de tecido ósseo, já que proporciona o crescimento de canais de sistemas nervosos, suporte para vasos sanguíneos como também suporte para deposição de fármacos. Dentre os fosfatos de cálcio, a hidroxiapatita se apresenta como fosfato mais estável, o qual é encontrado em maior proporção nos tecidos ósseo e dentário no organismo. Este trabalho teve por objetivo buscar nos bancos de artigos e de patentes trabalhos que relacionem a atividade antimicrobiana da hidroxiapatita, dando suporte a pesquisadores que trabalhem com esta cerâmica para aplicações em tecido dentário, como também a utilização da hidroxiapatita focando o suporte para incorporação de fármaco. Os bancos pesquisados foram o Scopus, Scielo e Web of Science para os artigos e USPTO, EPO e INPI para os bancos de patentes. Os critérios de exclusão levaram a 19 artigos que estudaram hidroxiapatita em conjunto com a clorexidina e zero patente encontrado. Dentre os artigos encontrados, a clorexidina é o fármaco mais empregado como agente antimicrobiano, e a bactéria mais utilizada nos testes é a gram-positiva Streptococcus mutans.