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BACKGROUND:IPS e. max Press porcelain crown has been widely used in clinical restoration because of its aesthetic effect and biological properties. OBJECTIVE:To explore the effect of IPS e. max Press porcelain crown in esthetic restoration of anterior teeth in terms of marginal adaptation and color match. METHODS:Total y 52 patients with 138 defective anterior teeth (20 males and 32 females, 18-45 years old, including 62 anterior tooth defects, 46 tooth traumas, 30 denticles) were divided into two groups randomly:treatment group (26 cases) and control group (26 cases) were given IPS e.max Press porcelain crown and conditional Co-Cr al oy handcuffed ceramic crowns, respectively. Al the cases were asked for a second visit in 1 week after restoration, and the integrity of ceramic veneer, marginal adaptation, gingival health and color match were evaluated during 6-month and 2-year fol ow-ups. RESULTS AND CONCLUSION:The degrees of satisfaction on the color, shape and adaptation in the treatment group were al higher than those in the control group (P<0.05). At 6 months after restoration, the marginal adaptation, gingival health and color match in the treatment group were al better than those in the control group (P<0.05). At 2 years after restoration, there was also a significant difference in the marginal adaptation, gingival health and color match between the two groups (P<0.05). IPS e.max Press porcelain crown has the advantages of aesthetics and biological characteristics, so it can be used as an ideal restoration method for esthetic restoration of anterior teeth.
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BACKGROUND:To maintain the long-term effect of ful crown largely depends on the health of periodontal tissues. OBJECTIVE:To explore the effect of CAD/CAM zirconia al-ceramic crown restoration on the state of periodontal health. METHODS:Sixty-four abutments of 55 patients were randomly divided into two groups:the experimental group included 32 abutments of 29 patients which would be restored by CAD/CAM zirconia al-ceramic crowns;the control ed group included 32 abutments of 26 patients which would be restored by Ni-Cr al oy porcelain-fused-to-metal restorations. The volume of gingival crevicular fluid and the levels of interleukin-6 and tumor necrosis factor-αin the two groups were examined at the pre-restoration and post-restoration stages. Meanwhile, periodontal clinical indicators, including sulcus bleeding index, probing depth, plaque index and attachment loss were recorded. RESULTS AND CONCLUSION:No difference in various indexes was found in the experimental group before and after restoration (P>0.05). At 12 months after restoration, in the control group, the volume of gingival crevicular fluid, the levels of interleukin-6 and tumor necrosis factor-α, sulcus bleeding index, probing depth, and plaque index were al increased (P>0.05);meanwhile, these indexes in the experimental group were significantly lower than those in the control group (P<0.05). Experimental findings suggest that the CAD/CAM zirconia al-ceramic crown restoration is more favorable to the health of periodontal tissues.
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BACKGROUND:Studies have shown that selection of implant crowns that directly impact the service life of implants and patient’s periodontal health is very important. OBJECTIVE:To compare the clinical effects of Lava zirconia crowns, goal-platinum al oy ceramic crowns and silver-pal adium al oy crowns supplemented by dental implants used in the single missing posterior tooth. METHODS:Sixty patients with first molar missing (120 teeth) were divided into three groups and treated with Lava zirconia, goal-platinum al oy ceramic and silver-pal adium al oy crowns applied to the dental implants for posterior column defects. The clinical restorative effects of three prostheses were compared. RESULTS AND CONCLUSION:During 6-48 months of fol ow-up, the gingival edge coloring, gingival margin microleakage, the color of prosthesis of Lava zirconia al oy ceramic crowns and gold-platinum al oy ceramic crowns were better than those of silver-pal adium al oy crowns, and the gingival edge coloring and the color of prosthesis of Lava zirconia al oy ceramic crowns were better than those of gold-platinum al oy ceramic crowns, while the gingival margin microleakage of gold-platinum al oy ceramic crowns was better than that of Lava zirconia al oy ceramic crowns. Silver-pal adium al oy crowns were lower than Lava zirconia ceramic crowns and gold-platinum al oy ceramic crowns in the fracture extent. But silver-pal adium al oy crowns had the highest gingival index, the worst gingival health and rapidest and most severe plaque formation. Therefore, Lava zirconia al-ceramic crowns and gold platinum al oy-porcelain crown are ideal prostheses for implant restorations. The former has better biocompatibility, and the latter shows better marginal adaptation.
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BACKGROUND:The patients with porcelain-fused-to-metal crowns who do examination of magnetic resonance imaging (MRI) can cause artifacts. In recent years, researching for MRI artifacts of different porcelain-fused-to-metal materials has been some progress, but there are less quantitatively reports on the MRI artifacts of different porcelain-fused-to-metal materials. OBJECTIVE:To evaluate the artifact sizes shown on fast spin-echo T 2-weighted sequence caused by different kinds of porcelain-fused-to-metal crowns. METHODS:Forty-eight lower right first molar crown patients who had MRI examination in MRI room were enrol ed. The patients were divided into nickel-chromium al oy group, cobalt-chromium al oy group and titanium crown group. Al patients were examined with fast spin-echo T 2-weighted sequences by means of 1.5 T MRI apparatus. MRI artifacts areas of same sequence on the MRI images of different porcelain-fused-to-metal materials were analyzed with variance test. RESULTS AND CONCLUSION:Forty-five cases appearing to have high signal samples with clearly curved boundary zone that can be measured were selected, 15 cases for each material. Different artifact sizes were produced on the same sequence of different porcelain-fused-to-metal materials, which were (321.67±33.29) mm in the nickel-chromium al oy group, (263.53±34.95) mm2 in the cobalt-chromium al oy group, and (143.67±31.13) mm2 in the titanium crown group. There were significant differences between groups (P<0.05). The artifact size is smal est for the titanium crown and largest for the nickel-chromium al oy crown.