Objective To discuss morphology and biomechanics of the sacrum fractures so as to provide scientific basis for corresponding clinical treatment. Methods A total of 10 fresh pelvis specimens were collected for dynamic impact test and static destruction test, in the former one of which, the dynamic parameters were measured to make sure the dynamic characters of the fractures. Meanwhile, the fractures of the sacrum wing, the sacral foramina and the sacrum edge were made decalcification, slice of paraffin wax and staining (Masson, Mallory, HE) in order to make a cytological observation of the tissue. Results (1) The form of sacrum fracture or acetabulum fracture, crista iliaceis fracture was relevant to the impact energy. Low impact energy usually caused fractures of the ilium, acetabulum or sacroiliac crest. High impact energy resulted in following three kinds of fractures, just as the classification of Denis: sacral ala fractures belonged to typeⅠfractures, sacral hiatus fractures to type Ⅱ fractures and central vertebral canal fractures to type Ⅲ fractures. All three types of fractures might involve lateral or bilateral nerve roots. (2) There was a significant mechanic difference in regard of the mechanism of both dynamic destruction and static destruction of pelvis, ie, not only the limit pressure differed but also the former increased rapidly with the higher rate of the strain. The clash energy beyond 25 J would beget the cleft fractures of the sacrum via sacrum hiatus and even involve the nerve roots. The clash energy under 20 J usually resulted in fractures of the ilium and the sacrum. The clash energy between 20 J and 25 J more easily caused type Ⅰ fractures. While fracture of the ilium and the acetabulum would happen most in static destruction. (3) The cross section of the sacrum was cracked and the bone board of Haversian system is brittle, as led to separation of bone board and malposition of a few cross bone boards. Conclusions Under dynamic state, the sacrum fractures mostly belong to type Ⅰ and type Ⅱ (Denis classification of sacral fractures), usually involving the nerve roots. The sacrum fracture is relevant to the microstructure, the distribution of the bone trabecula, the osseous lacuna and the Haversian system of the sacrum. The fractures of the ilium and the acetabulum more frquently appear in static state, with slight wound of peripheral tissues.

Objective To study the changes of biochemical components in GCF between children and adults during orthodontic tooth movement .Methods 84 patients(child group:43 subjects,adult group:41subjects)were included,each having one treatment tooth and one contralateral control tooth.The levels of PGE2,IL-6 and GM-CSF in GCF of upper lateral incisor were investigated befoe activation and at 24th hour after the applying of labial orthodontic force,by using of highly sensitive radioimmunoassay.Results PGE2,IL-6 and GM-CSF were highly detectable in GCf(>90%).At experimental sides,total amount of GCF PGE2,IL-6 and GM-CSF levels was significantly elevated at 24 th hour compared with that before activation in both child group and adult group.Mean concentration of PGE2 in GCF increased significntly at 24th hour in the two groups,while that of IL-6 and GM-CSF did only in child group.The levels of Pge2,IL-6 and GM-CSF in GCF remained at baseline throughout the study for the control teeth.Conclusion There were some differences of GCF cytokine changes between child and adult groups

Objective:To evaluate the efficacy and safety of endoscopic retrograde cholangiopancreatography (ERCP) after pancreaticoduodenectomy and endoscopic selection strategies.Methods:Clinical data of 34 patients treated with ERCP after pancreaticoduodenectomy at the Endoscopic Center of the First Affiliated Hospital of Air Force Medical University from January 2013 to December 2021 were retrospectively analyzed. The success rates of endoscopic insertion, diagnosis, treatment and ERCP, and the incidence of adverse events were analyzed.Results:Fifty ERCP treatments were performed in 34 patients. The success rates of endoscopic insertion, diagnosis, treatment, and ERCP after pancreaticoduodenectomy were 92.0% (46/50), 93.5% (43/46), 88.4% (38/43) and 76.0% (38/50), respectively. The success rates of ERCP assisted with colonoscope and balloon-assisted enterosocpe were 76.0% (19/25) and 75.0% (18/24), respectively. There were 3 adverse events, including 1 case of anastomotic mucosa tear during surgery, 1 case of cardiopulmonary arrest and 1 case of postoperative cholangitis.Conclusion:ERCP is effective and safe after pancreaticoduodenectomy in general. ERCP assisted with colonoscope and balloon-assisted colonoscope shows similar success rate after pancreaticoduodenectomy.

Sub-gingival anaerobic pathogens can colonize an implant surface to compromise osseointegration of dental implants once the soft tissue seal around the neck of an implant is broken. In vitro evaluations of implant materials are usually done in monoculture studies involving either tissue integration or bacterial colonization. Co-culture models, in which tissue cells and bacteria battle simultaneously for estate on an implant surface, have been demonstrated to provide a better in vitro mimic of the clinical situation. Here we aim to compare the surface coverage by U2OS osteoblasts cells prior to and after challenge by two anaerobic sub-gingival pathogens in a co-culture model on differently modified titanium (Ti), titanium-zirconium (TiZr) alloys and zirconia surfaces. Monoculture studies with either U2OS osteoblasts or bacteria were also carried out and indicated significant differences in biofilm formation between the implant materials, but interactions with U2OS osteoblasts were favourable on all materials. Adhering U2OS osteoblasts cells, however, were significantly more displaced from differently modified Ti surfaces by challenging sub-gingival pathogens than from TiZr alloys and zirconia variants. Combined with previous work employing a co-culture model consisting of human gingival fibroblasts and supra-gingival oral bacteria, results point to a different material selection to stimulate the formation of a soft tissue seal as compared to preservation of osseointegration under the unsterile conditions of the oral cavity.
Acid Etching, Dental ; methods ; Alloys ; chemistry ; Bacterial Adhesion ; physiology ; Bacteriological Techniques ; Biofilms ; Cell Adhesion ; physiology ; Cell Culture Techniques ; Cell Line, Tumor ; Cell Movement ; physiology ; Ceramics ; chemistry ; Coculture Techniques ; Dental Alloys ; chemistry ; Dental Etching ; methods ; Dental Implants ; microbiology ; Dental Materials ; chemistry ; Dental Polishing ; methods ; Humans ; Osseointegration ; physiology ; Osteoblasts ; physiology ; Porphyromonas gingivalis ; physiology ; Prevotella intermedia ; physiology ; Surface Properties ; Titanium ; chemistry ; Yttrium ; chemistry ; Zirconium ; chemistry

Retention wires permanently bonded to the anterior teeth are used after orthodontic treatment to prevent the teeth from relapsing to pre-treatment positions. A disadvantage of bonded retainers is biofilm accumulation on the wires, which produces a higher incidence of gingival recession, increased pocket depth and bleeding on probing. This study compares in vivo biofilm formation on single-strand and multi-strand retention wires with different oral health-care regimens. Two-centimetre wires were placed in brackets that were bonded to the buccal side of the first molars and second premolars in the upper arches of 22 volunteers. Volunteers used a selected toothpaste with or without the additional use of a mouthrinse containing essential oils. Brushing was performed manually. Regimens were maintained for 1 week, after which the wires were removed and the oral biofilm was collected to quantify the number of organisms and their viability, determine the microbial composition and visualize the bacteria by electron microscopy. A 6-week washout period was employed between regimens. Biofilm formation was reduced on single-strand wires compared with multi-strand wires; bacteria were observed to adhere between the strands. The use of antibacterial toothpastes marginally reduced the amount of biofilm on both wire types, but significantly reduced the viability of the biofilm organisms. Additional use of the mouthrinse did not result in significant changes in biofilm amount or viability. However, major shifts in biofilm composition were induced by combining a stannous fluoride- or triclosan-containing toothpaste with the mouthrinse. These shifts can be tentatively attributed to small changes in bacterial cell surface hydrophobicity after the adsorption of the toothpaste components, which stimulate bacterial adhesion to the hydrophobic oil, as illustrated for a Streptococcus mutans strain.
Base Sequence ; Biofilms ; DNA Primers ; Electrophoresis, Polyacrylamide Gel ; Humans ; Oral Hygiene ; Orthodontic Retainers ; Polymerase Chain Reaction ; Stainless Steel