Tantalum-incorporated hydroxyapatite coating on titanium implants: its mechanical and in vitro osteogenic properties.

OBJECTIVE: The fabrication of bioactive coatings on metallic implants to enhance osseointegration has become a topic of general interest in orthopedics and dentistry. Hydroxyapatite (HA) coating has been shown to induce bone formation and promote bone-implant integration. Unfortunately, poor mechanical performance has hindered this from becoming a favorable coating material. The majority of present studies have focused in incorporating different elements into HA coatings to improve mechanical properties. In recent years, tantalum (Ta) has received increasing attention due to its excellent biocompatibility and corrosion resistance. The aim of on the present study was to investigate the fabrication and biological performance of Ta-incorporated HA coatings. METHODS: Ta-incorporated HA coatings were fabricated using the plasma spray technique on a titanium substrate, and the surface characteristics and mechanical properties were examined. In addition, the effects of Ta-incorporated HA coatings on the biological behavior of mesenchymal stem cells (BMSCs) were investigated. RESULTS: Ta-incorporated HA coatings with microporous structure had higher roughness and wettability. In addition, the bonding strength of Ta/HA coatings with the substrate was substantially superior to HA coatings. Furthermore, Ta-incorporated HA coatings not only facilitated initial cell adhesion and faster proliferation, but also promoted the osteogenic differentiation of BMSCs. CONCLUSION: These results indicate that the incorporation of Ta could improve mechanical performance and increase the osteogenic activity of HA coatings. The Ta-incorporated HA coating fabricated by plasma spraying is expected to be a promising bio-coating material for metallic implants.

Primary Extra Nodal Diffuse Large B-Cell Lymphoma of the Maxillary Sinus with Symptoms of Acute Pulpitis.

Diffuse large B-cell lymphoma not otherwise specified (DLBCL-NOS) is a subtype of large B-cell non-Hodgkin lymphoma with various clinical and pathological manifestations. DLBCL-NOS which primarily arises from maxillary sinus is rare and hard to diagnose due to unique anatomy. Here, we present a case of DLBCL-NOS that developed in the left maxillary sinus of a 72-year-old male, who presented with severe toothache that resembled acute pulpitis. The lesion was diagnosed and treated based on radiographs, histological, immunohistological examinations, and PET-CT analysis. Despite its rare incidence, DLBCL-NOS should still be included in differential diagnoses to rule out malignancy in cases of endodontic disease.

[Experiment on inducing human dental pulp stem cells into neural-like cells].

OBJECTIVE: To explore the multi-differentiated capability of human dental pulp stem cells (hDPSCs) obtained by cell-clone culture approach and to determine the appropriate induced medium. METHODS: The cloned isolation and expansion of hDPSCs were preinduced for 24 h, and were subsequently replaced with neural-inductive medium containing certain concentration of dimethylsulfoxide (DMSO), butylated hydroxyanisode (BHA), forskolin, P-mercaptoethanol (p-ME) and hydrocortisone for 4 days. Then induced cells were analyzed by morphological observation, immnocytochemical staining for non-specific esterase (NSE) and glial fibrillary acidic protein (GFAP) expression, RT-PCR for GFAP mRNA. Meanwhile, the uninduced hDPSCs were used as negative control. RESULTS: The morphology of induced cells changed at the initial 12 h, and displayed a typical neuron-like cells at 24 h. There was a gradual increase in the number of these neuronal differentiated cells with continuous induction. Furthermore, immnocytochemical staining showed that the induced cell expressed NSE and GFAP, two marked enzymes of neuron cell. The GFAP mRNA was also detected in induced cells by RT-PCR assay. In contrast, the uninduced cells maintained its original appearance and had no expression on them. CONCLUSION: hDPSCs may possess potential of multiple-differentiation and may differentiate into neuron-like cells on certain inductive condition.