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BACKGROUND: Light-curing composite resins have been applied in the dental repair due to its beautiful color, excellent physical and chemical properties and easy to operation. However, its insufficient mechanical properties tend to cause composite fractures, resulting in undesired clinical efficacy.OBJECTIVE: To investigate the preparation, properties and biomechanical performances of filler-co-augmented photo-curable resin-based oral materials.METHODS: The nano-silica surface-grafted with poly(methyl methacrylate) (PMMA) was obtained by atom transfer radical polymerization. Co-electrospinning was used to prepare the acrylonitrile/PMMA core-shell nanofibers, and a two-dimensional lactic acid-glycolic acid copolymer nanofiber membrane with a lattice structure was obtained using a copper mesh as a receiving device. The multi-scale and multi-dimensional packing was prepared by sol-precipitation method with silane coupling agent as a raw ethyl ester precursor, and further modified using silane coupling agent. The mechanical properties, volumetric shrinkage, toxicity, and degradation properties of the light-curing resin grafted with SiO2-PMMA were compared with those of the light-curing resin combined with trapezoidal polysiloxane materials grafted with methyl methacrylate. RESULTS AND CONCLUSION: (1) Characterization of the composite resin under scanning electron microscope: the filler SiO2-PMMA core-shell nanofibers dispersed well in the light-curing resin matrix, in the presence of monodisperse phenomenon and less aggregation phenomenon. However, the trapezoidal polysiloxane material in the light-curing resin matrix dispersed unevenly, in the presence of reunion phenomenon. (2) The flexural strength, flexural modulus and fracture work of the light-curing resin graftedwith SiO2-PMMA core-shell nanofibers were significantly higher than those of the trapezoidal polysiloxane-based light-curing resin (P < 0.05). (3) The volume shrinkage of the light-curing resin grafted with SiO2-PMMA core-shell nanofibers was lower than that of the trapezoidal polysiloxane-based light-curing resin (P < 0.05). (4) Compared with the trapezoidal polysiloxane-based light-curing resin, the water absorption and cytotoxicity (absorbance value) of the light-curing resin grafted with SiO2-PMMA core-shell nanofibers were significantly higher than those of the trapezoidal polysiloxane-based light-curing resin (P < 0.05), while the solubility of the light-curing resin grafted with SiO2-PMMA core-shell nanofibers was lower (P < 0.05). It is concluded that the prepared light-curing resin grafted with SiO2-PMMA core-shell nanofibers has excellent properties and biomechanical properties.
ABSTRACT
BACKGROUND:The sensitivity andmucus secretion of theoral mucosamake oral soft tissues difficult to repair, so patients cannot achieve satisfactory outcomes after treatment. Nano-celulose protein mainly composed of glycine, alanine and serine has good histocompati bility. However, there is a lack of comparative study about the effect of nano-celulose protein and acelular matrix in oral mucosa repair, and the clinical effects of the two materials are stil under discussion. OBJECTIVE:To investigate the effects of nano-celulose proteinver susacelular matrix in oral mucosa repair. METHODS:Oral mucosadefect models were preparedinrats, and these rat models were randomly divided into four groups:oral mucosa defectswere repaired by vaseline (control group), nano-celulose protein, bovine skin acelular matrix and human skin acelular matrix, respectively. Repair effects were compared among different materials within 2 months after surgery. RESULTS AND CONCLUSION:The diameter of oral mucosa defect measured using a vernier caliper, had no significant differences among groups at 1 day after surgery (P> 0.05); the diameter of oral mucosa defect in the nano-celulose protein group was significantly lower than that in the other groups at 3, 5 and 7 days after surgery (P 0.05);but there were significant differences in the number of newborn capilary endothelialcels between the control group and the other three groups (P< 0.05). Furthermore, at 21 days after surgery, closely aligned and thicker new epithelialtissuecould be found in the nano-celulose protein group; in the bovine acelular matrix group,thedefect regionwasrepaired wel, new epithelialtissueappeared andthe number of inflammatory cels decreased; in the human acelular matrix group, inflammatory cels appearedobviously, and new epithelialtissueformed with the normal thickness. In contrast,abundant inflammatory cels and thinner epithelial tissues appeared in the control group. To conclude,bothnano-celulose protein and acelular matrix can accelerate wound healing by promoting oral mucosal epithelial hyperplasia.
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BACKGROUND:Fibroin is a natural macromolecular material with Arg-Gly-Asp peptide structure that is a special tripeptide structure closely related to cel adhesion, and it can promote cel migration, adhesion, and proliferation and influence cel morphology and function. OBJECTIVE:To compare the effects of different silk fibroin scaffolds to repair buccal mucosa defects in rats. METHODS:Ninety Sprague-Dawley rats were selected to make unilateral buccal mucosa defect models, and randomly divided into three groups, 30 rats in each group: porous silk fibroin scaffold was implanted into the buccal mucosa defect in experimental group, multi-layered crosslinked silk fibroin film was implanted into the buccal mucosa defect in control group, and vaseline gauze was used to cover the buccal mucosa defect folowed by suturing in blank control group. After 15 days, wound diameter was detected; after 30 days, bone defect tissues were taken for hematoxylin-eosin staining. RESULTS AND CONCLUSION:At postoperative 15 days, the wound diameter was significantly smaler in the experimental group than the control and blank control groups (P < 0.05), as wel as smaler in the control group than the blank control group (P < 0.05). Hematoxylin-eosin staining showed that at 30 days after operation, there were more epithelial spikes and fibroblasts, but less inflammatory cels in the experimental group than the other two groups (P < 0.05), and fibroin fibers were partialy absorbed and degraded in the experimental group. These findings indicate that porous silk fibroin scaffold for buccal mucosa defect repair can accelerate epithelialization and wound healing.
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Combined with the routine work of preventing and treating diseases, the construction of a clean and honest administration in stomatological hospital would be beneficial to raise the administrative staff's awareness of the constructive characteristics of a clean and honest administration in their work belief and methods to enhance the work initiative and effectiveness.
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23 cases were treated with immediate full denture.The second base-remodeling or re-prosthodontic treatment was given 3 months later based on the oral condition.Masticatory efficiency (ME)was measured at each stage.About 30% patients participated in the second base-remodeling procedure with ME of 52.63%.
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BACKGROUND: Resin filling, full crown and veneer are used in cosmetic restoration of anterior teeth. Doctors prefer resin because of its perfect clinical effect and small hurt. Some patients complain of sensitivity after rsein filling and we are interest in choosing a better resin with less sensitivity.OBJECTIVE: To compare the incidence of postoperative sensitivity and the difference of the patients' self sensitivity alter cosmetic restoration of anterior teeth with vital pulp by 3M-Z350 Nano-resin and 3M-Z100 composite resin. METHODS: A total of 112 teeth with vital pulp because of caries or traumatic tooth fractures of 68 patients demanding cosmetic restoration were selected from the Department of Endodontics, Stomatological Hospital of Luzhou Medical College from August to December 2006. The teeth were random divided into 3M-Z350 group and 3M-Z100 group, with 56 teeth in each group. 3M-Z350 nano-rasin and 3M-Z100 composite resin were used for cosmetic restoration of anterior teeth with vital pulp. Ryge criteria were used to evaluate the sensitivity to the cold stimulation following cosmetic restoration, and the level of pain was detected by the pain ruler.RESULTS AND CONCLUSION: Compared with 3M-Z100 group, the incidence of sensitivity and self-pain level were decreased in the 3M-Z350 group at 1 day, 1 week, and 1 month after restoration (P < 0.01 or P < 0.05). There was no significant difference in the sensitivity and self-pain level between the two groups (P > 0.05). Anterior teeth with vital pulp were well restored by 3M-Z350 nano-resin which might reduce the incidence of postoperative sensitivity.