非负荷期种植体周围牙槽骨丧失的X线观察

目的：研究非负荷期种植体周围骨吸收的时间变化规律。方法：以非埋植型纯钛种植体植入狗下颌骨，术后每月拍一次标准牙片，用Photoshop 6.01软件测量种植体周围骨吸收的量并加以分析。结果：种植体植入后第一个月骨吸收为0．64mm，每二个月为0．01mm，第三、四、五个月分别为0．04mm,0.15mm,0.24mm，第一个月骨吸收量与其余四个月之间有显著性差异（P＜0．05）。结论：种植体植入后第一个月骨吸收最多，可能与手术创伤引起的骨组织改建局部加速现象有关。     

上下颌游离缺失Brnemark种植义齿早期临床效果的比较研究

目的:比较上下颌游离缺失Branemark种植义齿修复早期临床效果。方法 :5例上颌 (17颗 )和7例下颌(22颗 )游离缺失Branemark种植体植入金合金烤瓷桥修复行使功能18个月后 ,比较上下颌游离缺失Branemark种植体支持固定桥义齿的稳固情况、种植体周牙龈指数和种植体周骨吸收量。结果 :上下颌游离缺失Branemark种植体支持固定桥义齿种植体周骨吸收量无显著性差异 (P>0.05) ;两者种植体周牙龈均处于正常状态 ;上下颌游离缺失种植义齿均未见种植体松动或脱落 ,基台和全冠的稳固性均良好。结论 :上下颌游离缺失Branemark种植体支持种植固定桥义齿修复效果良好     

Flurbiprofen-induced stimulation of periosteal bone formation and inhibition of bone resorption in older rats

The skeletal effects of flurbiprofen (Fb), a nonsteroidal antiinflammatory drug, was studied by histomorphometry in 9-month-old retired female breeder, Sprague-Dawley rats. Flurbiprofen was given subcutaneously at 0, 0.2, 0.1, 0.5, 2.5, or 5 mg/kg/d for 21 days. Flurbiprofen had no effect on longitudinal growth, but stimulated radial growth (+200%) over controls. In the tibial shaft, Fb stimulated the mineral apposition rate (+25%), mineral bone formation rate (+100%), and periosteal labeling length (+64%) at the 2.5 and 5.0 mg Fb/kg dose levels, and had no effect on marrow cavity size compared to controls. However, these changes were insufficient to increase cortical bone mass. In the proximal tibial metaphysis, Fb suppressed osteoclasts/mm² of metaphyseal tissue (-47%), osteoclasts/mm of bone surface (-46%), and the osteoclast/osteoblast ratio (-50%), increased the calcified cartilage core population (+100%), and had no effect on osteoblast numbers at all dose levels. There was an insignificant increase in metaphyseal cancellous bone mass. The current study leads to the conclusion that flurbiprofen-stimulated periosteal bone growth was due to direct stimulation of osteoblast recruitment and activity independent of longitudinal bone growth. Further, it confirms early findings in young rats that flurbiprofen induced depressed bone resorption without lowering bone formation. However, because of insufficient treatment time, the older rat did not accumulate bone as the young rats did.     

调节性T细胞源性IL-10与TGF-β1对破骨细胞分化及骨吸收的抑制作用

示出对破骨细胞分化与骨吸收功能明显的协同抑制作用.结论 调节性T细胞源性细胞因子IL-10与TGF-β1对破骨细胞分化与骨吸收功能具有抑制作用.     

External root resorption following bleaching of pulpless teeth with oxygen peroxide

Abstract Eleven teeth in which bleaching with 30% oxygen peroxide was followed by external root resorption are presented. One tooth had no traumatic history, while the others were previously subluxated or luxated in accidental injury. Radiographic appearance of resorptions varied. In 2 teeth the resorptions were only superficial and did not progress during the observation time. In 5 teeth the resorptions were associated with ankylosis. In the remaining 4 teeth the resorption was progressive, bowl-shaped and associated with radiolucency in the adjacent alveolar bone. It was suggested that damage to the periodontium, caused by oxygen peroxide at the time of treatment, may heal or be followed by ankylosis and, when complicated by bacterial contamination, develop to a progressive root resorption associated with persistent inflammatory changes in periodontal tissues.     

低分子壳寡糖对LPS诱导的小鼠颅骨吸收的抑制作用

目的: 研究低分子量壳寡糖（low-molecular chitosan oligosaccharide,LMCOS）对脂多糖（lipopolysaccharides,LPS）诱导的小鼠颅骨吸收模型的影响,评估其在小鼠颅骨吸收过程中的抑制作用。 方法: 将6周龄C57/BL6雄性小鼠随机分为 5组,即磷酸缓冲液（PBS）组、LPS组、LPS+0.005% LMCOS组、LPS+0.05% LMCOS组和LPS+0.5% LMCOS组;每组5只,LPS的刺激量为10 mg/kg。小鼠浅麻醉后,于颅盖骨皮下注射相应试剂,每只注射300 μL。每周小鼠头部皮下组织和颅骨骨膜之间注射试剂3次,2周后处死,取出颅盖骨进行Micro-CT扫描、H-E染色、TRAP 染色。采用SPSS21.0软件包对数据进行单因素方差分析,观察骨破坏面积、破骨细胞的形成等骨缺损表现。 结果: Micro-CT扫描、H-E染色、TRAP 染色发现,与PBS组相比,LPS组小鼠颅骨表面的骨破坏十分明显;加入不同浓度的LMCOS后,颅骨骨破坏面积及破骨细胞数目随LMCOS浓度的升高而不断减少。 结论: LMCOS具有抑制LPS诱导的小鼠颅骨骨吸收的作用,提示LMCOS对骨破坏性疾病可能具有一定的治疗作用。     

Interleukin-1α produced in human gingival fibroblasts induces several activities related to the progression of periodontitis by direct contact

Previous observations suggest that interleukin-1 (IL-1) may play an important role in the progression of periodontitis. In the present study, we investigated whether a cell-associated IL-1α (CAIL-lα) produced in human gingival fibroblasts (HGF) induces biological activities related to the progression of periodontitis. HGF were treated with recombinant human IL-1β (rhIL-1β) for 12 h. After that, the cell layers of HGF were washed 3 times with fresh medium and were then fixed with 1% paraformaldehyde. The fixed cell layers of HGF were used for assays for bone resorbing activity, prostaglandin E₂ (PGE₂) production and collagenase activity. Fixed cell layers of HGF treated with rhIL-1β enhanced not only calcium release from BALB/c mouse calvaria but also PGE₂ production and collagenase activity in HGF and human periodontal ligament fibroblasts (HPLF) cultured on the fixed cell layers. These activities were neutralized by treatment with monoclonal mouse anti-human IL-1α antibody, but monoclonal mouse antihuman IL-1β antibody showed no effects on these activities. The induction of these activities by fixed cell layers of HGF required direct contact between the fixed cell layers and the calvaria, HGF, or HPLF. These results suggest that CAIL-1α produced in HGF treated with rhIL-1β induces bone resorbing activity, PGE₂ production and collagenase activity in the target cells by direct contact; CAIL-lα may play an important role in the progression of periodontitis.     

Effect of outer membrane of Treponema denticola on bone resorption

The effect of the outer membrane (outer sheath) of Treponema denticola on bone resorption was studied. Bone resorption was measured by the release of previously incorporated ⁴⁵Ca from the shafts of the radii and ulnae of 19-day fetal rats. A treated-over-control ratio (T/C ratio) significantly greater than 1 indicated the stimulation of bone resorption by the test substance. The addition of outer membrane of T. denticola increased the release of ⁴⁵Ca from the assay bones. The minimum concentrations required to yield significant ⁴⁵Ca release from the assay bones were 15, 22 and 75 μg protein/ml for serovars a, b and c, respectively. These protein values corresponded to estimated lipopolysaccharide contents of 0.6, 0.8 and 2.8 μg/ml, based on 3-deoxy-2- manno -octulosonate analysis. Heat treatment of outer membrane (60° for 30 min) did not change the effect on ⁴⁵Ca release. Parathyroid hormone or prostaglandin E₂ known to act synergistically with lipopolysaccharides in bone resorption, was also added to the assay system. Neither prostaglandin E₂ at 10^-7 M nor parathyroid hormone at 40 ng/ml, by itself, increased ⁴⁵Ca release. However, in the presence of 10 μg protein/ml of outer membrane of serovar b at 120 h, the T/C ratio was increased to 1.31±0.07 and 1.58±0.118, respectively. These results suggest that a lipopolysaccharide-like material is present in the outer membrane of T. denticola that may be responsible for bone resorption in the in vitro system.     

Splinted and unsplinted overdenture attachment systems: A systematic review and meta‐analysis

Splinted and unsplinted overdenture attachment systems have unique advantages and disadvantages. The aim of the present systematic review was to determine the influence of splinted and unsplinted overdenture attachment systems on the marginal bone loss, prosthetic complications and implant survival rate. PubMed/MEDLINE , Scopus and Cochrane databases were searched for articles published up to October 2017, using the following search terms: “overdenture AND attachment OR overdenture AND bar OR overdenture splinted.” The PICO question “Do splinted overdenture attachment systems promote better clinical results in comparison to unsplinted systems?” was evaluated. Eligible studies included randomized controlled clinical trials, prospective studies with at least 10 participants and a minimum follow‐up of 6 months, and studies published in English that compared splinted and unsplinted attachment systems within the same study. The 95% confidence interval (CI ) was considered for all outcomes analysed. After completion of the different steps in the article selection process, nine articles were included in the qualitative and quantitative analyses. A total of 984 implants were placed in 380 patients (mean age: 62.8 years). The meta‐analysis demonstrated no statistically significant differences between splinted and unsplinted attachment systems with regard to marginal bone loss (P  = .39; MD : ?0.11; 95% CI : ?0.37 to 0.14), complications (P  = .31; RR : 1.26; CI : 0.80‐1.99) and implant survival rate (P  = .14; RR : 0.37% CI : 0.10‐1.36). In addition, splinted and unsplinted overdenture attachment systems achieved similar results with regard to marginal bone loss, prosthetic complications and implant survival rate.