Enucleation combined with guided bone regeneration in small and medium-sized odontogenic jaw cysts.

BACKGROUND: The odontogenic jaw cyst is a cavity containing liquid, semifluid or gaseous components, with the development of the disease. In recent years, with the rapid development of oral materials and the transformation of treatment of jaw cysts, more options are available for treatment of postoperative bone defect of jaw cysts. Guided bone regeneration (GBR) places biomaterials in the bone defect, and then uses biofilm to separate the proliferative soft tissue and the slow-growing bone tissue to maintain the space for bone regeneration, which is widely used in the field of implantology. AIM: To observe the clinical effect of GBR in repairing bone defect after enucleation of small and medium-sized odontogenic jaw cysts. METHODS: From June 2018 to September 2020, 13 patients (7 male, 6 female) with odontogenic jaw cysts were treated in the Department of Oral Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. Adults without hypertension, heart disease, diabetes or other systemic diseases were selected. The diagnosis was based on the final pathological results: 11 cases were diagnosed as apical cysts, one as primordial cyst, and one as dentigerous cyst. The lesions were located in the maxilla in seven cases, and in the mandible in six cases. All cases were treated with the same method of enucleation combined with GBR. RESULTS: Three to four months after the operation, the boundary between the implant site and the surrounding normal stroma was not obvious in patients with small-sized odontogenic jaw cysts. The patients with tooth defects were treated with implant after 6 mo. For the patients with medium-sized odontogenic jaw cysts, the density of the center of the implant area was close to the normal mass at 6 mo after surgery, and there was a clear boundary between the periphery of the implant area and the normal mass. The boundary between the periphery of the implant area and the normal mass was blurred at 8-9 mo after surgery. Patients with tooth defects were treated with implants at > 6 mo after the operation. CONCLUSION: Enucleation combined with guided bone regeneration in small and medium-sized odontogenic jaw cysts can shorten the time of osteogenesis, increase the amount of new bone formation, reduce complications, and improve quality of life.

[Analysis of virulence-related properties of P. gingivalis clinical isolates].

PURPOSE: To analyze the relation of virulence properties and pathogenicity of Porphyromonas gingivalis (P.gingivals) isolated from Chinese patients. METHODS: Based on the previous analysis of virulence properties, investigations of pathogenicity properties, including the adhesion to host cells, gingipain activities, and resistance to host immune reaction were performed to analyze the diversity of pathogenic properties of these strains. SAS 8.02 software package was used for statistical analyses. RESULTS: Less-virulent type strain showed higher adherence ability to host red blood cells and weaker resistance to serum killing, while virulent type strain showed the opposite reactions. However, the clinic isolates presented just the opposite relationship between virulence properties and pathogenicity. In addition, there was no obvious correlation between gingipain activities and virulence properties of P. gingivalis strains. CONCLUSIONS: The results suggested that there is no obvious linkage between the P. gingivalis virulence properties and pathogenicity diversity.

Comparison of biological characteristics of mesenchymal stem cells grown on two different titanium implant surfaces.

This study examined the biological characteristics of mesenchymal stem cells (MSCs) grown on sand-blasted, large-grit, acid-etched (SLA) surface and hydroxyapatite (HA) coating on the SLA (HA/SLA) surface of titanium dental implants. The HA/SLA surfaces of titanium dental implants were formed by the ion beam assisted deposition (IBAD) method. Rabbit bone marrow derived mesenchymal stem cells cultured in vitro were seeded onto the surface of SLA and HA/SLA; the growth states of MSCs on the two samples were observed by a scanning electron microscope; the proliferation index, alkaline phosphatase (ALP) activity, osteocalcin (OCN) content of MSCs and mRNA relative expression level of osteopontin (opn) were compared between two groups. MSCs were found to be easier to adhere to the HA/SLA surface compared to the SLA surface. At the same time, the ALP activity and the OCN content of MSCs grown on the HA/SLA surface were obviously higher, and the relative expression level of opn mRNA was 4.78 times higher than that on the SLA surface. The HA coating formed by the IBAD method on the SLA surface of titanium dental implants significantly improves proliferation and well-differentiated osteoblastic phenotype of MSCs, which indicates a promising method for the surface modification of titanium dental implants.