Objective To investigate the morphology and bonding of enamel and dentin conditioned by 35% phosphoric acid and pulse Nd:YAG laser.Methods A total of 52 human premolars were selected,40 of which were divided into four groups randomly: group A [enamel treated with 35% phosphoric acid(Scotchbond,3M) for 30 s];group B [enamel treated with pulse Nd:YAG laser(Evlaser Friendly A4 Italy) for 20 s];group C(dentin treated with 35% phosphoric acid for 15 s);group D(enamel treated with pulse Nd:YAG laser for 15 s).The tensile bond strength(TBS) were determined.Except 4 out of 12 human premolars without any treatment,8 were divided into 4 groups and were treated with the method mentioned above.The surfaces of 12 human premolars were observed under SEM.Results The highest TBS was obtained in group A in comparison with the other 3 groups(P0.05).The smear layer on enamel and dentin could be removed after conditioned by both phosphoric acid and pulse Nd:YAG laser.The honeycomb structures were observed on all enamel but less regularly in lased group.Almost all the orifices of dentinal tubules were open in the acid group and sealed or half-sealed in lased group.Conclusion The pulse Nd:YAG laser did not contribute to bonding of enamel,but could improve the bonding of dentin and seal most of the orifices of dentinal tubules,which reduced the harmful stimulation to the dental pulp.

Objective To research the clinical significance of acetated Ringer solution and succinylated gelatin in the fluid resuscitation of sepsis patients.Method Fifty-nine sepsis patients were divided into two groups:lactic acid Ringer solution and hetastarch (group A,27 cases)and acetated Ringer solution and suecinylated gelatin (group B,32 cases),compared the fluid resuscitation and other parameter.Results There were no significant difference in the central venous pressure,mean arterial pressure and the dose of noradrenaline (P ＞ 0.05).The activated partial thrombeplastin time in group A was longer than that in group B[(58±10),(74±13)s vs(48±7),(54 ±11) s in 6,24 hours],fibrinogen concentration was lower than that in group B [(3.3 ±0.8),(1.6±0.3)g/L vs (4.2±1.1),(2.1±0.2)g/L in 6,24 hours] (P＜0.05).Serum lactic acid,creatinine,calcium concentration in group A [(6.9±0.8)retool/L,(289 ~ 27)μ mol/L,(2.1 ±0.3)mmol/L]were higher than those in group B [(3.2 ±1.1)mmol/L, (193 ±42)μmol/L, (1.7±0.2)mmol/L](P＜0.05),there was no difference in APACHE Ⅲ scores on the third day between two groups (P＞0.05).Conclusions Acetated Ringer solution and succinylated gelatin in the fluid resuscitation of sepsis patients has the same effect,but fewer impacts on serum coagulation,serum lactic acid and renal function than lactic acid Ringer solution and hetastareh.They may be more suitable for fluid resuscitation of sepsis patients,but hypecalcemia is easy to happen,and there is no significant evidences proving the prognosis.

Objective:To investigate the effects of BMP9 combined with NGF on the osteogenic differentiation of mesenchymal stem cells(MSCs).Methods:Recombinant BMP9 adenovirus was transfected into C3H10T1/2 cells.The cells were treated by GFP,NGF,BMP9 and BMP9 + NGF respectively.The expression level of COL1,RUNX2 was detected by RT-PCR and Western blot,ALP activity was examined by ALP kit 3,12,24,48 hours,3 and 7 days after treatment,respectively.Results:The ALP activity of BMP9 + NGF group was the highest among the 4 groups.The difference in the groups firstly appeared at 3 h after treatment.The highest expression level of RUNX2 and COL1 was detected in BMP9 + NGF group.Conclusion:NGF and BMP9 may synergisticly promote osteogenic differentiation at the early stage of osteogenic induction of C3H10T1/2 cells.

Objective To evaluate the expression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) in ovarian cancer cell lines, and to investigate the biological effects of down-regulated MALAT-1 on OVCAR3 cells.Methods qRT-PCR analysis was used to examine the expression level of MALAT-1 gene in ovarian cancer cells, including ES-2, A2780, SKOV3 and OVCAR3 cell lines.For functional research, four shRNA oligos specially targeting MALAT-1 and a empty vector were designed and constructed into pGPU6/GFP/Neo, then transfected into OVCAR3 cells.qRT-PCR was used to confirm the effective suppression of MALAT-1.Changes of proliferation and adhesion of cells were analyzed by CCK-8 and adhesion assays.Wound-healing, transwell migration and invasion assays were used to examine migration and invasion of MALAT-l-silencing cells in vitro.Results The expression of MALAT-1 gene in OVCAR3 cells was high, and qRT-PCR results confirmed successfully the knockdown of MALAT-1 after transient transfection.After successful suppression of MALAT-1, the proliferation, wound-healing and adhesion ability in vitro were inhibited to some degree.In transwell migration assay, the number of migration cells in MALAT-1-silencing group was 52.17±4.48, which is much less than that in the negative and control groups (286.50± 12.23 and 295.67±6.96, respectively).In invasion assay, the number of invasion cells passing the transwell membrane in MALAT-1-silencing group (37.33±2.40) was also decreased significantly, compared to that in the negative and control groups (239.00±15.72 and 222.67±20.85, P ＜ 0.05).Conclusions shRNA-mediated silence of MALAT-1 can effectively inhibit the proliferation, adhesion, migration and invasion abilities of ovarian cancer cell line OVCAR3 in vitro, indicating MALAT-1 is expected to be a target gene for the treatment of ovarian cancer.

The normal torque angle of the maxillary anterior teeth is an important factor in the aesthetics and function of the anterior teeth, and torque control of the front teeth is an extremely important aspect of the correction process. At present, the normal torque angle of the front teeth is among the phase Ⅲ clinical test items recognized by the American orthodontic professional committee; consequently, good control of front teeth torque is of great significance to the aesthetics of the upper anterior teeth. In this paper, the influence of a lip appliance on the bad torque of upper anterior teeth and the associated methods of control are reviewed in detail. The advantages and disadvantages of various control methods for the anterior teeth and the significance of correct anterior teeth torque angle are summarized. The existing research results indicate that the torsion of a straight arch wire applied directly to individual teeth is too great, making it difficult to enter the groove. Although the bending of the arch wire overcomes these shortcomings, the procedure is cumbersome; it stimulates the soft tissue of the vestibular groove and increases the patient’s discomfort. The bending mechanism of the rocking chair is more complicated; it is greatly affected by the friction between the arch wire and the bracket and is not conducive to closing the tooth extraction gap using the sliding method. The portal auxiliary arch and the single bending torque are suitable for correcting the torque angle of a single tooth. Auxiliary arch torque can be used to correct the upright upper anterior teeth during the process of closing the extraction space and after adduction; therefore, this procedure is worth popularizing. However, the accuracy of orthodontic control of anterior teeth torque requires further study.

OBJECTIVETo investigate the biological characteristic of ectomesenchymal stem cells (EMSC) and the differentiation of p75(+)EMSC and influencing factors.

METHODSThe immunohistochemical staining method was used to observe the migration of EMSC from 12.5 d SD rat embryonic facial process. Then EMSC was labeled by p75 neurotrophin receptor, and the cell cycle and stem cell surface antigens of the p75(+) EMSC was examined.

RESULTSImmunohistochemical staining showed that stem cells from the cranial neural crest migrated to embryonic rat facial process at 12.5 days. The sorting rate of the p75(+)EMSC was 6.1%. The proportion of the p75(+)EMSCs' S/G2/M phase was stable during subculture. The special substances CD29, CD146 and Stro-1 were marked for p75(+)EMSC, and the expressions of the markers were all higher (> 90%) in p75(+) EMSC.

CONCLUSIONSThe embryonic tooth did not start to grow on the conception 12.5 days of SD rats. The p75(+) EMSC after sorting had stable proliferation ability and had stem cell characteristics during subculture and didn't start differentiation.

Animals ; Biomarkers ; metabolism ; Cell Cycle ; Cell Differentiation ; Cell Division ; Cell Movement ; In Vitro Techniques ; Mesenchymal Stromal Cells ; chemistry ; physiology ; Rats ; Rats, Sprague-Dawley ; Receptor, Nerve Growth Factor

BACKGROUND:The application of miniscrew in adolescents is increasing day by day,but at present,there are few studies on bone mass in the external oblique line of the mandible in adolescents at home and abroad,and there is no systematic study on bone mass in the external oblique line of the mandible in adolescents in different growth and development periods. OBJECTIVE:To measure the bone mass in the external oblique line of the mandible in adolescents with different cervical vertebral bone ages using a cone-beam CT and to investigate the difference of bone mass in the external oblique line of the mandible in adolescents with different cervical vertebral bone ages and the correlation between bone mass in this area and the cervical vertebral bone age. METHODS:The cone-beam CT data of 105 adolescent patients before orthodontic treatment were collected and divided into CS3 group(n=24),CS4 group(n=26),CS5 group(n=29)and CS6 group(n=26)using the cervical vertebral maturation method.The adolescent mandibular buccal shelf was reconstructed by Mimics Medical 21.0 software.The width of buccal bone at 6 and 11 mm under the cemento-enamel junction and the bone height at 4 and 5 mm buccal to the cemento-enamel junction of right mandibular first and second molars were measured.The measured data were statistically analyzed.The measurement was made on four planes:plane 1 is the plane where the proximal mesial root of the mandibular right first molar is located;plane 2 is the plane where the distal mesial root of the mandibular right first molar is located;plane 3 is the plane where the proximal mesial root of the mandibular right second molar is located;and plane 4 is the plane where the distal mesial root of the mandibular right second molar is located. RESULTS AND CONCLUSION:In each group,the bone width on the buccal side of the external oblique line increased gradually from the first molar proximally to the second molar distally in adolescents,and the width of buccal bone at 6 and 11 mm under the cemento-enamel junction showed significant difference among different layers(P<0.05).The bone width of buccal bone at 11 mm under the cemento-enamel junction was greater than that at 6 mm.The bone height on the buccal side of the external oblique line increased gradually from the first molar proximally to the second molar distally in all four groups,and the bone height at 4 and 5 mm buccal to the cemento-enamel junction showed significant differences at different layers(P<0.05).The bone height at 4 mm buccal to the cemento-enamel junction was greater than that at 5 mm.On the fourth plane,the bone width at 11 mm buccal to the cemento-enamel junction was smaller in the CS3,CS4,and CS5 groups than in the CS6 group(P<0.05).On the third plane,the bone heights at 4 mm and 5 mm buccal to the cemento-enamel junction were smaller in the CS3 and CS4 groups than in the CS6 group(P<0.05).On the fourth plane,the bone height at 5 mm buccal to the cemento-enamel junction was smaller in the CS3 and CS4 groups than in the CS6 group(P<0.05).On the fourth plane,the bone height at 4 mm buccal to the cemento-enamel junction was smaller in the CS3 group than in the CS6 group(P<0.05).Spearman correlation analysis showed that there was no correlation between bone mass and the cervical vertebral bone age,except that there was a weak correlation between bone mass at some measurement sites and cervical vertebral bone age.To conclude,the bone mass in the external oblique area of the mandible in adolescents does not change significantly with the increase of cervical vertebral bone age.The buccal side of the mesial root and distal root of the mandibular second molar in the external oblique area of CS3-CS6 adolescents meets the requirement of bone mass for miniscrew implantation,which is a site available for miniscrew implantation.

Objective : To analyze the initial displacement of the upper central incisor and stress distribution of periodontal ligament under different torque values of upper incisors under the action of a four-curved auxiliary arch to provide a reliable basis for the safety of clinical application of four-curved auxiliary arches. Methods : A three-dimensional finite element model for torque control of upper anterior teeth with a homemade quadrilateral auxiliary arch was established. Four different states were analyzed: molar ligation without extraction space (group A), microimplant ligation without extraction space (group B), molar recovery with extraction space closure (group C) (the adductive traction force was set at 115 g) and microimplant recovery with extraction space closure (group D) (the adductive traction force was set at 115 g). When four types of torque (0.5 N, 1.0 N, 1.5 N, and 2.0 N) were applied. The initial displacement of upper central incisors and the stress distribution of periodontal ligament in 16 groups (A1-A4, B1-B4, C1-C4, D1-D4) were observed. Results : Under different conditions, as the strength of the four-curve auxiliary arch increases, the maxillary anterior teeth has crown labial inclination and a root lingual inclination. The displacement of the incisor tip increases with the increase in the loading force of the torque auxiliary arch, and the displacement of the incisor root apex increases as the force increases. The difference in incisor-apex displacement distance in A1-A4, B1-B4, C1-C4, D2 and D4 groups increased as the torque force increases, while the difference between the D3 group and D1 and D2 groups decreased slightly. The stress of the cervical periodontal ligament of the upper central incisor did not exceed the stress of the periodontal ligament in the following groups: A1, A2, B1, B2, B3, C1, C2, D1, and D2. The stress of the lip side of the upper central incisor did exceed the stress of the periodontal ligament in the following groups: A3, A4, B4, C3, C4, D3, and D4. In other words, when using the four-curved auxiliary arch as an implant anchorage, the force applied in the absence of extraction space should not exceed 1.5 N, and the force applied in the adduction of extraction space should not exceed 1.0 N. When using the nonimplant anchorage, the force applied in the absence of extraction space and the adduction of extraction space should not exceed 1.0 N. In addition, the range of force should not exceed the maximum stress of the periodontal ligament in the cervical region such that the effective and safe torque movement can be achieved. Under other stress conditions, the stress of the labial and cervical periodontal ligament of the upper central incisor exceeded the stress value (2.6 × 10-2MPa). The stress value of periodontal ligament was 2.6 × 10-2MPa in all groups. Conclusion A four-curved auxiliary arch has a significant effect on the upper anterior teeth, and the use of microimplants can better control root movement such that the crown of upper central incisors cannot be excessively lip inclined.

The p75 neurotrophic factor receptor is a low affinity receptor for neurotrophic factors and plays an important role in nerve growth, development and function integrity. It is closely related to dental development, oral and maxillofacial tumor, nerve repair and tissue engineering. It shows good prospect for application. In this paper, the research progress of p75 neurotrophic factor receptor in Stomatology is reviewed.