Sprayable methacrylic anhydride-modified gelatin hydrogel combined with bionic neutrophils nanoparticles for scar-free wound healing of diabetes mellitus.

Hard-to-healing or nonhealing diabetic wounds caused by hyperglycemia, bacterial infection and chronic inflammation are becoming a challenge globally. In this study, a novel hydrogel for diabetic wound healing composed of methacrylic anhydride-modified gelatin (GelMA) hydrogel and mimicking neutrophil nanoparticles was originally created. The prepared GelMA hydrogel has good sprayability and film-formation ability under blue light illumination (wavelength = 435-480 nm). Nanoparticles mimicking neutrophils belong to a double enzyme system that are encapsulated in ZIF-8 nanoparticles, which can consume glucose to produce HClO, ensuring a decrease in the glucose concentration of the wound and growth inhibition in bacteria. The hydrogel also has excellent biocompatibility, which can promote the growth and proliferation of fibroblasts. More importantly, the hydrogel can accelerate wound healing in type I diabetic rats owing to the downregulation of proinflammatory cytokines, and the wound with an area of 1 cm2 can be almost fully healed with no formation of the scar on the 21st day, as verified by histochemistry and immunohistochemistry. All these combinations indicate its potential in diabetic wound treatment.

[Influence of removable thermoplastic appliances and fixed appliances on periodontal status: a meta analysis].

PURPOSE: To evaluate the influence of removable thermoplastic appliances and fixed appliances on periodontal status. METHODS: Cochrane library, PubMed, EMBASE, CBM, CNKI, VIP, Wanfang Database were searched from the date of inception to 2017.10.16，to find clinical trials about removable thermoplastic appliances and fixed appliances on periodontal status. The quality of the included studies was assessed by two reviewers independently, and meta analysis was performed using RevMan5.3. RESULTS: Totally 11 studies including 543 patients were identified. The results of meta analysis showed there were significant difference in PLI and SPD at 3 months and PLI and GI at 6 months between removable thermoplastic appliances and fixed appliances, and no significant difference was observed in GI at 3 months and SPD at 6 months between the two groups. CONCLUSIONS: In the early orthodontic treatment, removable thermoplastic appliances has better effect than the fixed appliance on periodontal health.

[Distal movement of the mandibular dentition in the treatment of patients with Class III skeletal pattern].

OBJECTIVE: To evaluate the outcome of patients with skeletal Class III malocclusion treated with extraction of mandibular third molars and distalization of molars using implant anchorage combined with MBT appliance. METHODS: Fifteen patients (mean age 24.0 ± 5.8) with skeletal Class III malocclusion were selected. The mandibular third molars were extracted and the mandibular molars were moved distally using implant combined with MBT appliance. Cephalometric analysis was carried out before and after treatment. RESULTS: After active treatment, ANB, Wits distance, AB-NP and the distance between upper and lower lip position to SnPg' increased by 1.65° ± 1.04°, (4.39 ± 1.93) mm, 3.20° ± 1.61° and (1.13 ± 0.99) mm, respectively. The differences were statistically significant (P < 0.05). CONCLUSIONS: The skeletal Class III patients in the permanent dentition could be treated successfully with extraction of mandibular third molars and distalization of mandibular molars using implant anchorage combined with MBT appliance. The soft-tissue profile was improved.

[Comparison between one-step and two-step space closing methods of sliding mechanics using three-dimensional finite element].

UNLABELLED: To construct a three-dimensional finite element model comparing between one-step and two-step methods in torque control of anterior teeth during space closure. METHODS: Dicom image data including maxilla and upper teeth were obtained though cone-beam CT. A three-dimensional model was set up and the maxilla, upper teeth and periodontium were separated using Mimics software. The models were instantiated using Pro/Engineer software, and Abaqus finite element analysis software was used to simulate the sliding mechanics by loading 1.47 Nforce on traction hooks with different heights (2, 4, 6, 8, 10, 12 and 14 mm, respectively) in order to compare the initial displacement between six maxillary anterior teeth (one-step method) and four maxillary anterior teeth (two-step method). RESULTS: When moving anterior teeth bodily, initial displacements of central incisors in two-step method and in one-step method were 29.26 × 10⁻6 mm and 15.75 × 10⁻6 mm, respectively. The initial displacements of lateral incisors in two-step method and in one-step method were 46.76 × 10(-6) mm and 23.18 × 10(-6) mm, respectively. Under the same amount of light force, the initial displacement of anterior teeth in two-step method was doubled compared with that in one-step method. The root and crown of the canine couldn't obtain the same amount of displacement in one-step method. CONCLUSIONS: Two-step method could produce more initial displacement than one-step method. Therefore, two-step method was easier to achieve torque control of the anterior teeth during space closure.

[Comparison between the tooth length measured by cone-beam CT and the tooth length measured with vernier caliper].

OBJECTIVE: To evaluate the accuracy of cone-bean CT (CBCT) on the measurement of the tooth length. METHODS: One hundred and sixty single root premolars extracted for orthodontic purposes were selected. The tooth length was measured with vernier caliper. The premolars were divided into 10 groups randomly, 16 premolars in each group.In each group, the teeth were lined in molar area, premolar area, canine area and anterior tooth area in maxilla and mandible. Then CBCT was taken, and the tooth length was measured using the software supplied by the manufacturer in coronal and sagittal plane. Accuracy was compared between vernier caliper measurement and CBCT measurement. RESULTS: The tooth length measured by CBCT was smaller than that measured with the vernier caliper. Significant differences were found in six areas, except the maxillary and mandibular premolar areas. With the increase of mesial-distal inclination or buccolingual torque angle, the difference between tooth length measured by CBCT and that measured with vernier caliper increased. The correlation between buccolingual torque angle (∠X1) and the coronal view of CBCT radiology tooth length (Spearmen index was 7.00, P < 0.001), and the correlation between mesial-distal inclination and the coronal view of CBCT radiology tooth length (Spearmen index was 0.624, P < 0.001) were found. CONCLUSIONS: The tooth length measured by CBCT was smaller than that measured with vernier caliper.

[A scanning electron microscopic study of root surface following mini-implant anchorage for maxillary incisors intrusion].

PURPOSE: To establish an animal model for maxillary incisors intrusion with mini-implant as the anchorage and study the effect on the surface morphology of cementum after the force had been given. METHODS: 9 dogs were selected and randomly divided into 5 groups, group I was the control group(1 dog) with no force given; groups II,III,IV,V were experimental groups (2 dogs each). Mini-implants were inserted into the labial alveolar bone between the roots of second and third maxillary incisors on both sides, 100 gram force was imposed on the first and the second incisors on both sides.The animals were sacrificed at the end of 1, 2, 4,12 weeks (activation for 4 weeks,then retention for 8 weeks after force removal) respectively after activation.Scanning electron microscopy was used to examine the surface of the cementum. RESULTS: In group II, the surfaces of root tip had a little scratch, which was small,confined. In group III, near the apical 1/3 of root, lacunas were fused, but no dentin exposed. In group IV, at the junction of the apical 1/3 and the middle 1/3 of the root, lacunas went deep into the dentin,which were wide and serious. In group V, the surfaces of lacunas were low ,smooth and even. CONCLUSIONS: As the intrusion goes on, the area of absorption expands from the root tip to neck. Root resorption increases with the duration of the applied force prolonged and repair of the cementum occurs at the resorbed area after force removal.