Application progress of alveolar ridge preservation in patients with tooth extracted due to periodontitis / 口腔医学

@#Alveolar ridge preservation (ARP) has developed rapidly as a method for preserving the alveolar socket's bone volume after tooth extraction. ARP can create conditions for implant restoration, and reduce operation difficulties by decreasing alveolar ridge absorption. There are certain difficulties of ARP applicationin patients with tooth extracted due to periodontitis. This paper mainly introduces the characteristics of ARP, compares the similarities and differences among ARP, guided tissue regeneration, guided bone regeneration and immediate implant, and then summarizes their advantages and disadvantages. The paper focuses on the specificity of ARP and the progress of ARP application in patients with tooth extracted due to periodontitis, in order to offer direction for clinical application and future research on ARP.

Expert consensus on the bone augmentation surgery for alveolar bone defects / 口腔疾病防治

@#Alveolar bone is an important anatomic basis for implant-supported denture restoration, and its different degrees of defects determine the choices of bone augmentation surgeries. Therefore, the reconstruction of alveolar bone defects is an important technology in the clinical practice of implant restoration. However, the final reconstructive effect of bone quality, bone quantity and bone morphology is affected by many factors. Clinicians need to master the standardized diagnosis and treatment principles and methods to improve the treatment effect and achieve the goal of both aesthetic and functional reconstruction of both jaws. Based on the current clinical experience of domestic experts and the relevant academic guidelines of foreign counterparts, this expert consensus systematically and comprehensively summarized the augmentation strategies of alveolar bone defects from two aspects: the classification of alveolar bone defects and the appropriate selection of bone augmentation surgeries. The following consensus are reached: alveolar bone defects can be divided into five types (Ⅰ-0, Ⅰ-Ⅰ, Ⅱ-0, Ⅱ-Ⅰ and Ⅱ-Ⅱ) according to the relationship between alveolar bone defects and the expected position of dental implants. A typeⅠ-0 bone defect is a bone defect on one side of the alveolar bone that does not exceed 50% of the expected implant length, and there is no obvious defect on the other side; guided bone regeneration with simultaneous implant implantation is preferred. Type Ⅰ-Ⅰ bone defects refer to bone defects on both sides of alveolar bone those do not exceed 50% of the expected implant length; the first choice is autologous bone block onlay grafting for bone increments with staged implant placement or transcrestal sinus floor elevation with simultaneous implant implantation. Type Ⅱ-0 bone defects show that the bone defect on one side of alveolar bone exceeds 50% of the expected implant length, and there’s no obvious defect on the other side; autologous bone block onlay grafting (thickness ≤ 4 mm) or alveolar ridge splitting (thickness > 4 mm) is preferred for bone augmentation with staged implant placement. Type Ⅱ-Ⅰ bone defects indicate that the bone plate defect on one side exceeds 50% of the expected implant length and the bone defect on the other side does not exceed 50% of the expected implant length; autologous bone block onlay grafting or tenting techniques is preferred for bone increments with staged implant implantation. Type Ⅱ-Ⅱ bone defects are bone plates on both sides of alveolar bone those exceed 50% of the expected implant length; guided bone regeneration with rigid mesh or maxillary sinus floor elevation or cortical autologous bone tenting is preferred for bone increments with staged implant implantation. This consensus will provide clinical physicians with appropriate augmentation strategies for alveolar bone defects.

Acute postinfectious glomerulonephritis with a large number of crescents caused by Mycoplasma pneumoniae.

Mycoplasma pneumoniae-induced acute postinfectious glomerulonephritis has various pathological changes and relatively poor prognosis. It often occurs in children, barely in adults. Currently, no clear treatment guidelines have been established for its treatment using glucocor ticoid and immunosuppressive. In this study, we report an adult who admitted to our hospital due to fever and gross hematuria. The patient presented with nephritic syndrome and renal failure and confi rmed to have M. pneumoniae infection by serum detection and acute postinfectious glomerulonephritis with a large number of crescents by renal biopsy. He was given glucocorticoid, immunosuppressive agent combined with hemodialysis as well as other supportive treatment. Three months later, his renal function became normal, urine protein level decreased to 0.4 g/24 h, and the C3 complement increased to normal level. In conclusion, glucocorticoid and immunosuppressive treatment should be given to patients with M. pneumoniaeinfection induced glomerulonephritis after confi rmed to have a large number of crescents by renal biopsy and the treatment could improve the prognosis.

Influence of fluoride-containing acidic artificial saliva on the mechanical properties of Nickel-Titanium orthodontics wires.

Objective: This study aimed to investigate the influence of fluoride and an acidic environment on the mechanical properties of NiTi orthodontic wires (NiTiW) in artificial saliva. Design: A prospective laboratory investigation. Setting: Department of Stomatology, First Affiliated Hospital, Zhejiang University, Hangzhou, China. Materials and Methods: Commercial, round 0.016-inch NiTiW were immersed in 0% or 0.05% Natrium-Fluoride-containing artificial saliva at a pH of 4 or 6 for one or three days, respectively. NiTiW were examined with a three-point bending test, Vickers' microhardness tests and surface morphology observation (SEM). Results: A pH of 4 increased microhardness and decreased the three-point bending strength significantly (P≤0.05), whereas immersion time and fluoride concentration had no significant influence on the microhardness or on the three-point bending strength (P>0.05). When examining the test group NiTiWs after three days of immersion at a pH of 4 the SEM revealed a rough surface morphology, a damaged oxide layer and signs of corrosion. Conclusions: The most influential factor for decreasing the unloading force and increasing the hardness seems to be the pH value, whereas immersion time and NaF addition do not have a major influence.