Objective:To compare the bone dimensional changes following tooth extraction alone with extraction plus ridge preservation ( using deproteinized boving bone mineral Bio-Oss? and bioresorbable collagen mambrane Bio-Gide?) in periodontal compromised extraction sockets .Methods: Eighteen molars of sixteen subjects requiring tooth extraction because of periodontal destruction were enrolled in this study .The subjects were assigned to the control group ( extraction alone , EXT) or to the test group ( ridge-preservation procedure with Bio-Oss? and Bio-Gide?, RP) .Parallel periapical X-rays and cone-beam computed tomography ( CBCT ) scans were taken immediately after tooth extraction alone or plus ridge-preservation ( baseline ) and 6 months later .The changes of horizontal ridge width and vertical ridge height were assessed .Results:At the central buccal aspect , the ridge height increased 2 .9 mm in RP group, and reduced 1.0 mm in EXT group.At the distal buccal aspect , the ridge height increased 1.45 mm in RP group, and reduced 1.45 mm in EXT group.The differences between the groups reached statistical significance (P<0.05).The mean ridge width increased at the 1 mm below the crest (the horizontal ridge width was measured with grafting material at three levels at 1 mm below the most coronal aspect of the crest,HW1), which amounted to 3.40 to 5.80 mm in RP group, and 1.45 to 2.90 mm in EXT group.The mean ridge increased at the 4 mm below the crest ( the horizontal ridge width was measured with grafting material at three levels at 4 mm below the most coronal aspect of the crest ,HW4 ) , which amounted to 0.40 to 3.50 mm in RP group, and reduced 0.10 to increased 0.15 mm in EXT group.The test group and the control group were not significantly different (P>0.05).Conclusion:The ridge-preservation approach using Bio-Oss? in combination with Bio-Gide? can significantly increase vertical ridge height and horizontal ridge width after tooth extraction compared with extraction alone in periodontal compromised molars .

Objective:To evaluate bone formation in human extraction sockets with absorbed surrounding walls augmented with Bio-Oss(R) and Bio-Gide(R) after a 6-month healing period by histologic and histomorphometric analyses.Methods:Six fresh molar tooth extraction sockets in 6 patients who required periodontally compromised moral tooth extraction were included in this study.The six fresh extraction sockets were grafted with Bio-Oss(R) particle covered with Bio-Gide(R).The 2.8 mm × 6.0 mm cylindric bone specimens were taken from the graft sites with aid of stent 6 months after the surgery.Histologic and histomorphometric analyses were performed.Results:The histological results showed Bio-0ss(R) particles were easily distinguished from the newly formed bone,small amounts of new bone were formed among the Bio-Oss(R) particles,large amounts of connective tissue were found.Intimate contact between the newly formed bone and the small part of Bio-Oss(R) particles was present.All the biopsy cylinders measurement demonstrated a high inter-individual variability in the percentage of the bone,connective tissues and BioOss(R) particles.The new bone occupied 11.54％ (0-28.40％) of the total area;the connective tissues were 53.42％ (34.08％-74.59％) and the Bio-Oss(R) particles were 35.04％ (13.92％-50.87％).The percentage of the particles,which were in contact with bone tissues,amounted to 20.13％ (0-48.50％).Conclusion:Sites grafted with Bio-Oss(R) particles covered with Bio-Gide(R) were comprised of connective tissues and small amounts of newly formed bone surrounding the graft particles.

Objective:To investigate the changes of the vertical height and width of the alveolar bone six months after the alveolar ridge preservation in periodontal compromised molar sites of severe alveolar bone defects with clinical direct measurement,parallel periapical radiographs,and cone-beam computed tomography (CBCT),and to analyze the effect of the three different methods of measurement.Methods:In this study,20 subjects requiring tooth extraction on account of periodontal disease with a total of 23 ex-tracted molars were enrolled.Extractions were performed atraumatically and patients were received alveo-lar ridge preservation procedure with Bio-Ossand Bio-Gide.Clinical direct measurements were taken after tooth extraction and during the implant surgery 6 months later,CBCT scans and parallel periapical radiographs were taken immediately after ridge preservation and 6 months later.The changes of alveolar ridge width and vertical height after six months were measured and analyzed through the above-mentioned three methods and the similarities and differences of the measured effect were compared.Results:There were no significant difference of alveolar vertical height in the center of the extraction sites,the center of distal aspect,and distobuccal aspect between the clinical direct measurements and the CBCT measure-ments (P>0.05),alveolar vertical height in other points and alveolar width measurements were statical-ly significant (P<0.05).After 6 months,1 0 sites of 1 0 subjects were received a flap and re-entered to perform dental implants surgery.The vertical height in the center of alveolar increased significantly and the changes of alveolar vertical height of clinical direct and CBCT measurement were (6.1 5 ±1 .73)mm and (6.59 ±2.53)mm,respectively.The measurements of the width of the alveolar bone were (8.45 ± 1 .1 8)mm and (8.52 ±1 .27)mm,respectively.The measurements of the two methods were not statisti-
cally significant (P>0.05).The change of the alveolar height in the center of the extraction socket after six months measured by parallel periapical was (5.84 ±4.28)mm,which was closed to the clinical di-rect measurement and the CBCT measurement.Conclusion:Clinical direct measurement and CBCT measurement were largely consistent in the evaluation of the alveolar bone height and width after the alveolar ridge preservation using deproteinized boving bone mineral (DBBM,Bio-Oss)and bioabsor-bable collagen membrane (Bio-Gide)in periodontal compromised molar sites of severe bone defects.

BACKGROUND:Schwann cells are important celllines in the process of repairing peripheral nerve injury, and human amniotic homogenate supernatant is shown to secrete a variety of cytokines, which could promote the proliferation of Schwann cells.
OBJECTIVE:To investigate the effect of different concentrations of human amniotic homogenate supernatant on the proliferation of rat Schwann cell96.
METHODS:Schwann cell96 was cultured with high-glucose DMEM containing 20%fetal bovine serum, and the second generation of Schwann cell96 was applied for experiments. The cultured cells were divided into five groups according to different volume fractions of human amniotic homogenate supernatant (0%, 10%, 15%, 20%, 25%) in the medium.
RESULTS AND CONCLUSION:The total protein concentration of human amniotic homogenate supernatant was 675μg/mL, in which the concentration of epidermal growth factor, basic fibroblast growth factor and vascular endothelial growth factor were respectively (470.625±2.546), (4.121±0.026) and (0.172±0.002) ng/L. At 1-7 days, the cellproliferation rate of the 10%and 15%concentration groups was greater than that in 20%and 25%concentration groups (P<0.05);10%and 15%concentrations promoted cellproliferation, while 20%and 25%concentrations inhibited cellproliferation. There were no significant difference in the viability of Schwann cell96 between the control group and the experimental group (P>0.05). Low concentrations (10%, 15%) of human amniotic homogenate supernatant promote the proliferation of Schwann cell96, while high concentrations (20%, 25%) of human amniotic homogenate supernatant inhibit cellproliferation.

Objective: To explore mechanism of lung injury of rats induced by inhalation of white smoke from burning smoke pot. Methods: Forty-eight Sprague Dawley rats were divided into control group (n=12) and injury group (n=36) according to the random number table. Rats in injury group were placed in smoke-induced injury experimental equipment fulled with white smoke from burning smoke pot for 5 minutes to make lung injury, and rats in control group were placed in smoke-induced injury experimental equipment fulled with air for 5 minutes to make sham injury. Six rats in injury group at post injury hour (PIH) 6, 24, and 72 and six rats in control group at PIH 72 were collected to observe pathological changes of lung tissue and pathological score of rats in the two groups by hematoxylin-eosin staining, to detect expression of nuclear factor-κB (NF-κB) p65 mRNA in lung tissue of rats by reverse transcriptional polymerase chain reaction, and to detect content of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 in lung tissue of rats by enzyme-linked immunosorbent assay. Data were processed with one-way analysis of variance and t test. Results: At PIH 72, lung tissue structure of rats in control group was clear and complete, with no inflammatory cell infiltration. At PIH 6, there was edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group. At PIH 24, edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group aggravated. At PIH 72, area of edema in lung tissue of rats in injury group was enlarged, with obvious hemorrhage and inflammatory cell infiltration. At PIH 6, 24, and 72, pathological score of lung tissue of rats in injury group was (3.43±0.86), (5.39±0.93), and (9.99±0.84) points, respectively, obviously higher than that of rats in control group at PIH 72 [(2.11±0.20) points, t=3.659, 8.450, 22.355, P<0.05]. As time post injury prolonged, pathological scores of lung tissue of rats in injury group were significantly increased (F=121.244, P<0.01). At PIH 6, 24, and 72, expression of NF-κB p65 mRNA in lung tissue of rats in injury group was 15.5±4.3, 25.9±1.8, 30.9±3.5 respectively, significantly higher than that of rats in control group at PIH 72 (7.8±0.8, t=4.315, 20.445, 14.408, P<0.01). As time post injury prolonged, expression of NF-κB p65 mRNA in lung tissue of rats in injury group gradually increased (F=32.691, P<0.01). At PIH 6, 24, and 72, content of TNF-α, IL-1β, and IL-6 in lung tissue of rats in injury group was significantly higher than that of rats in control group at PIH 72, respectively (t=7.650, 8.968, 6.827, 6.726, 8.978, 3.460, 5.420, 13.289, 16.438, P<0.01). At PIH 24, content of TNF-α and IL-1β in lung tissue of rats in injury group was higher than that of rats in the same group at PIH 6 and 72, respectively (t=3.409, -2.549, 4.047, -4.100, P<0.05). At PIH 24 and 72, content of IL-6 in lung tissue of rats in injury group was respectively higher than that of rats in the same group at PIH 6 (t=8.273, 9.711, P<0.05). Conclusions After inhaling white smoke from burning smoke pot, rats are inflicted with lung injury by increasing expression of NF-κB p65 mRNA and content of TNF-α, IL-1β, and IL-6, and induce pathological changes of edema, hemorrhage, and inflammatory cell infiltration of lung tissue.

Gingival Stillman's cleft is a mucogingival triangular- shaped defect which influence on health and appearance of gingiva. Due to a lack of clinical reports, five cases of gingival Stillman's cleft were recruited in the present study. The treatment methods were selected according to the etiological factors of the defect in each patient. Satisfactory treatment responses were achieved in all cases during a 6 to 20 month follow up after the treatments. In this study, we summarized the treatment strategies in various types of gingival Stillman's cleft, so as to provide the reference for clinicians.