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BACKGROUND:To measure the occlusal force index of patients with missing teeth before and after restoration is an effective way to evaluate the restoration effect and oral function recovery after dental restoration.OBJECTIVE:To observe the changes of occlusal force and periodontal tissue in patients undergoing CO-Cr alloy-based porcelain-fused-to-metal crown and bridge restoration.METHODS:100 male patients were randomly divided into five groups (n=20 per group), and respectively received CO-Cr alloy porcelain crown restoration of the anterior teeth (group A), CO-Cr aloy porcelain crown repair of the premolar (group B), CO-Cr aloy porcelain crown restoration of the molar (group C), CO-Cr alloy porcelain bridge restoration of the anterior teeth (group D), or CO-Cr alloy porcelain bridge restoration of the posterior teeth (group E). Changes of occlusal force and periodontal related indexes were detected before, immediately and 6 months after dental restoration.RESULTS AND CONCLUSION:(1) Occlusal force: The occlusal force in all the five groups was increased immediately and 6 months after restoration (P 0.05) before and after restoration. To conclude, the CO-Cr alloy-based porcelain-fused-to-metal crown and bridge restoration can significantly enhance the patient's occlusal force of the abutment teeth, exert little effect on the periodontal tissue and have good biocompatibility.
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OBJECTIVE@#To investigate clinical effect of individual light-curing resin tray as edge plastic material in complete denture modulo. @*METHODS@#A total of 30 patients with poor condition for alveolar ridge of mandible were chosen individual tray with individual light-curing resin tray for material edge shaping or traditional individual impression tray for edge shaping cream to produce complete denture. The operability, questionnaire about denture retention, comfort, mucosal cases and chewing function in the process of shaping the edge were investigated three months later after wearing dentures. @*RESULTS@#There was no significant difference in retention, comfort, mucosa and the chewing function between the two mandibular denture impression methods. However, the patients with individual light-curing resin tray as edge shaping material felt better in the process than that in the patients with die-cream as the edge shaping material (P<0.05). Furthermore, the manipulation with individual light-curing resin tray as edge shaping material is easy for doctor. @*CONCLUSION@#Although the clinical effect of Individual light-curing resin tray material as the edge shaping material is equal to that of impression cream, it saves time and human resource. Moreover, it is more acceptable for the patients and thus it can be spread in clinics.
Subject(s)
Humans , Acrylic Resins , Dental Impression Materials , Dental Impression Technique , Denture, Complete , Light-Curing of Dental AdhesivesABSTRACT
21 classII malocclusion adolescents (9 boys and 12 girls) were selected as the subjects, aged from 10.6 to 14.5 years, and the initial mean age was 12.8 years. All were treated with the modified Pendulum appli-ance. The duration for distalization of maxillary molars was from 3.2 to 5.7 months (4.3 months on average). Lat-eral cephalograms were obtained before and after distalization. Changes produced by the modified Pendulum appli-ance were analyzed with paired t tests. The mean space opening on lateral cephalograms was 7.31 mm, and maxil-lary first molar distalization accounted for 64.8% of the space,with a mean distal crown tipping of 18.64o. The rate of molar movement was 1.27 mm per month. The maxillary first molars intruded 0.69 mm,and the premolars extru-ded 1.02 mm. Lower anterior facial height increased 2.19 mm. The maxillary incisors had increased 3.39oof labial tipping and 1.13 mm of protrusion.
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BACKGROUND:Nano-calcium titanate, prepared with different modifiers, have properties of good osteogenesis, bone conductibility and biocompatibility. OBJECTIVE:To observe the influence of nano-calcium titanate materials on the proliferation and differentiation of osteoblasts. METHODS:Nano-calcium titanate was prepared with modifiers such as polyethylene glycol, acetyl trim ethyl ammonium bromide and sodium citrate. Meanwhile, nano-calcium titanate without modifier was prepared. Al the four kinds of nano-calcium titanate materials were used to prepare nano-calcium titanate extracts under the concentration of 0.1, 1.0, 10 g/L, respectively. The proliferation of osteoblasts was observed through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and alkaline phosphatase activity of osteoblasts was observed. Osteoblasts cultured in normal condition served as contrast. RESULTS AND CONCLUSION:The proliferation of osteoblasts cultured in the calcium titanate extracts prepared with polyethylene glycol, acetyl trim ethyl ammonium bromide and sodium citrate and without modifier was obviously improved under the concentration of 1.0 and 10 g/L. Absorbance value of the cells cultured in the above-mentioned four kinds of calcium titanate extracts 1.0 and 10 g/L) for 3, 6, 9 days exceeded the contrast (P<0.05, P<0.01), as wel as the alkaline phosphatase activity (P<0.05, P<0.01). Calcium titanate prepared with polyethylene glycol, acetyl trim ethyl ammonium bromide and sodium citrate and without modifier has no cytotoxicity effect on osteoblasts, and can promote the proliferation and differentiation of osteoblasts.
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Objective To reconstruct three-dimensional finite element analysis all-ceramic crowm model of the first maxillary molar.Methods After the CT scanning and image processing to the first maxillary molar in vivo,a 3-D geometric model was established by the Imageware software.The mesh model was then built in Abaqus,the finite element analysis software.Result The three dimensional finite element all-ceramic crown models of the first maxillary molar was constructed on the computer,which had 60 160 nodes and 186 328 tetrahedrons elements.Conclusion The finite element model constructed has the advantages of intact structure and precise elements,can simulate the natural condition and facilitate the further biomechanical research.