RESUMO
Objective:To prepare the lithium-doped poly-glycerol sebacate (PGS-Li) scaffold using the specific effects of lithium ions and the excellent performance of PGS, and to provide the basis for its application prospects in cementation tissue engineering scaffold.Methods:The scaffolds were divided into two groups.The PGS-Li scaffolds prepared by adding lithium phosphate during the PGS cross-linking process were used as PGS-Li group, and the PGS scaffolds synthesized by the equal-purification of sebacic acid and glycerol were used as PGS group.The molecular weights of the scaffolds in two groups were determined by gel permeation chromatography.The structures of the scaffolds in two groups were analyzed by fourier transform infrared spectroscope.The surface morphology and the porosities and the pore sizes of the scaffolds in two groups were observed by scanning electron microscope.X-ray photoelectron (XPS) spectroscope and inductively coupled plasma optical emission spectrometer were used to determine the Li ion contents in the scaffolds in two groups.Thermogravimetric analyzer was used to analyze the thermal stabilities of the scaffolds in two groups.Contact angle measuring instrument was used to compare the hydrophilicities of the scaffolds in two groups.In vitro weight loss test was used to determine the degradation rates of the scaffolds in two groups.The OCCM-30cells were divided into experimental group (added with PGS-Li scaffold extract) , PGS group (added with PGS scaffold extract) and blank control group (added with DMEM culture medium) .MTT assay was used to detect the proliferation activities of cells in various groups at different time (24, 48and 72h) ;the cell morphology was observed by calcein-AM staining.Results:The gel permeation chromatography results showed that the molecular weight of the PGS-Li scaffold was slightly larger than that of the PGS scaffold.The specific absorption peak of phosphate was detected in the fourier infrared spectrum of the PGS-Li scaffold.The scaffolds in two groups had irregular three-dimensional network structures under scanning electron microscope, and the pore size was 20-160μm, the porosity of PGS scaffold was (53.92±2.18) ％, and the porosity of PGS-Li scaffold was (53.58±1.73) ％, there was no statistical difference between two groups (P＞0.05) .The XPS results showed that a peak appeared at 54.9eV in PGS-Li group, which coincided with the Li 1s binding energy, while the inductively coupled plasma emission spectrometer results showed that the Li ion content in the PGS-Li scaffold was 0.084％.The thermogravimetric analysis results showed that PGS-Li scaffolds began to degrade at a higher temperature and ceased at a lower temperature compared with PGS scaffolds.The contact angle measurement results indicated that both the materials were hydrophilic materials;the contact angle of PGS scaffold meterial was 78.26°±2.00°, and the contact angle of the PGS-Li scaffold material was 69.78°±1.15°;there was statistical difference between two groups (P＜0.05) .The in vitro degradation experiments showed that the degradation rate of PGS-Li scaffolds was faster than that of PGS scaffolds.The proliferation activity of OCCM-30cells in PGS-Li group had no significant difference compared with PGS group and blank control group (P＞0.05) .The calcein-AM staining results showed the green fluorescence in the OCCM-30cells in PGS and PGS-Li groups, and there were no significant changes in the morphology of cementoblasts.Conclusion:PGS-Li scaffolds have similar composition and structure to PGS scaffolds, and have better performance in hydrophilicity and thermal stability.PGS-Li scaffolds have no effect on the proliferation of cementoblasts and have broad application prospects in cementum tissue engineering.
RESUMO
Objective: To analyze the postoperative satisfaction and repair effect of prosthesis of the patients who received digital smile design(DSD) combined with porcelain veneers in the anterior teeth, and to illustrate the their application in anterior teeth aesthetic restoration. Methods: A total of 91 anterior teeth of 32 patients whose clinical diagnosis conformed to the indications of porcelain veneers and aesthetic restoration because of tetracycline pigmentation teeth, dental fluorosis, color stained teeth, enamel defects and anterior teeth space were selected. DSD software was used to design the preoperative aesthetic analysis of the teeth morphology and to show the virtual effect of restoration. The preparation of tooth under the guidance of the design results was finished. The IPS e-max porcelain veneers were prepared after the conventional impression preparation. At last, the permanent restorations were manufactured and bonded to teeth. After the adhesive program was completed, the satisfaction of the patients in the shape of restorations, the degree of coordination with the adjacent teeth, color, pronunciation, smile effect and doctor-patient communication effect were evaluated by the questionnaires. The patients were required to regularly return after one month, three months, six months and twelve months, and observe the clinical effects of restoration was observed referring to the modified American Public Health Service (USPHS) standard. Results: The patients' satisfaction rates of each evaluation content were all over 90%. Among them, the satisfaction rates of the smile effect and the doctor patient communication were as high as 100%. The clinical performances of the rehabilitations in each period were as follows: One month after treatment, there were four teeth occurred mild gingivitis and three teeth appeared the postoperative sensitivity symptoms; three months after treatment, there were one tooth showed a minor fracture in the restoration without affecting the appearance and function and three teeth had mildly congestive gums reaction, at the same time one tooth showed slight discoloration of the restoration; six months after treatment, one tooth showed ceramics fracture of restoration and four teeth developed mild gingivitis; twelve months after treatment, two teeth showed ceramics fracture, the edge of three restorations had slightly crack and one tooth appeared gingivitis. The periodontal conditions of the patients with gingival inflammation after treatment were improved significantly after receiving the correct oral hygiene guidance. The above defects didn't affect the aesthetics effect and the functions of restorations, and the restorations could be used normally after intraoral adjustments. Both the doctors and the patients were satisfied with the repair effects of the restorations. Conclusion: The combination of DSD and porcelain veneer in repairing anterior aesthetic teeth is good treatment plan that can achieve high patient satisfaction and ideal clinical effect.