Effect of Hydroxyapatite Microspheres, Amoxicillin-Hydroxyapatite and Collagen-Hydroxyapatite Composites on Human Dental Pulp-Derived Mesenchymal Stem Cells.

In this study, the preparation and characterization of three hydroxyapatite-based bioactive scaffolds, including hydroxyapatite microspheres (HAps), amoxicillin-hydroxyapatite composite (Amx-HAp), and collagen-hydroxyapatite composite (Col-HAp) were performed. In addition, their behavior in human dental pulp mesenchymal stem cell (hDPSC) culture was investigated. HAps were synthesized through the following methods: microwave hydrothermal, hydrothermal reactor, and precipitation, respectively. hDPSCs were obtained from samples of third molars and characterized by immunophenotypic analysis. Cells were cultured on scaffolds with osteogenic differentiation medium and maintained for 21 days. Cytotoxicity analysis and migration assay of hDPSCs were evaluated. After 21 days of induction, no differences in genes expression were observed. hDPSCs highly expressed the collagen IA and the osteonectin at the mRNA. The cytotoxicity assay using hDPSCs demonstrated that the Col-HAp group presented non-viable cells statistically lower than the control group (p = 0.03). In the migration assay, after 24 h HAps revealed the same migration behavior for hDPSCs observed compared to the positive control. Col-HAp also provided a statistically significant higher migration of hDPSCs than HAps (p = 0.02). Migration results after 48 h for HAps was intermediate from those achieved by the control groups. There was no statistical difference between the positive control and Col-HAp. Specifically, this study demonstrated that hydroxyapatite-based bioactive scaffolds, especially Col-Hap, enhanced the dynamic parameters of cell viability and cell migration capacities for hDPSCs, resulting in suitable adhesion, proliferation, and differentiation of this osteogenic lineage. These data presented are of high clinical importance and hold promise for application in therapeutic areas, because Col-HAp can be used in ridge preservation, minor bone augmentation, and periodontal regeneration. The development of novel hydroxyapatite-based bioactive scaffolds with clinical safety for bone formation from hDPSCs is an important yet challenging task both in biomaterials and cell biology.

Relationship between taste perception and use of upper complete dentures.

AIMS: The aim of the present study was to evaluate the taste perception in patients with upper complete dentures. METHODS AND RESULTS: One hundred seventy male and female patients (45-83 years old) upper denture wearers were evaluated for their gustatory function by the paper strips technique in relation to the four basic tastes. The taste test was performed with and without the presence of the denture on the palate. Through Shapiro-Wilk and Kolmogorov-Smirnov tests, the results were analyzed by their normal distribution. The t-test for paired samples was used to evaluate if there was a statistical difference on the taste perception and itself revealed that there is a significant difference (p < 0.01) when the taste perception was analyzed for the absence and presence of the prosthesis (alone and compared) (p < 0.01). The results revealed that patients with dentures had great difficulty to recognize the bitter taste, followed by the salty, sweet, and sour. CONCLUSION: The presence of the denture was able to modify the perception of taste when compared to its absence, especially for the bitter taste.