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Objective To investigate the correlation between posterior neck pain and lumbar epidural pressure (LEP)during percutaneous endoscopic lumbar discectomy (PELD).Methods A prospective study was performed on 86 patients undergoing PELD,46 males,40 females,aged 1 9-71 years,with ASA physical status of Ⅰ or Ⅱ.Each patient received lumbar epidural anesthesia.Lum-bar epidural pressure (LEP)was monitored continuously through a lumbar epidural catheter which was connected to a pressure transducer.LEP before the operation (LEPbase ),LEP at the time of pos-terior neck pain (LEPpain )and maximal LEP (LEPmax )were recorded.Results Thirty patients (34.9%)complained of posterior neck pain during the procedure.The lowest LEPmax was 31.0 mm Hg,and the highest LEPmax was 77.0 mm Hg.The LEPmax in patients with neck pain [(60.6± 8.8)mm Hg]was significantly higher than LEPmax in patients without neck pain [(50.7 ± 9.5 ) mm Hg](P <0.01 ).Patients with higher LEPmax had higher probabilities of having posterior neck pain (P <0.01).Conclusion Patients with higher LEPmax had higher probabilities of having posterior neck pain.
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Objective To investigate the effects of a corrective tr ea tment on open bite malformations, such as gnash their teeth, nail-biting, tongu e thrusting, impacted tooth, cross bite with improper correction, open bite defo rmity resulted from premature shedding of deciduous tooth and molar cysts. Methods We used dental resin technology: acid etching the teeth, adh ering metal clasps to the teeth by means of composite resin, and applying elasti c bands for intermaxillary traction to correct the cross bite. Results We had treated 22 patients, age ranged from 7-30, with the malformatio ns resulted from different kinds of reasons, and obtained significant results. Conclusion With cooperation of the patients, simple corrections for open bite with sticky clasp and occlusion with elastic band are easy to car ry on, with short period of treatment time, and every patient gets prominent out come. It is effective, prior to commonly-used corrective therapy and deserves t o be widely used.
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Objective: To study the bonding interface characteristic of five wet bonding systems while bonding on different dentin bonding surfaces. Methods: Rhodamine B was used to label five adhesives(OptiBond Sol o,Single Bond,Gluma One-Bond,Bond-1 and One-Step) in consistency of 0.1%, an d the bonding interface of the 5 wet bonding systems on dry or wet dentin surfa ces was observed with laser scanning confocal microscope. Results: All five bonding systems could infiltrate well into dentin bonding interface when bonding on wet dentin surface. The fluorescence confocal images gave eviden ce of the adhesives penetrated into the widened tubules, lateral tubules and dem ineralized peritubular dentin. Little discontinuity in dentin tubular was observ ed in the images, especially in those of alcohol-water-based adhesives. When b onded in dry dentin surface, the hybrid thickness of acetone-based adhesives de creased significantly. Conclusion: The penetration ability of ad hesives may be reduced significantly on dry dentin surface.
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0.05) than those with that of 1.0 mm (P
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0.05), the FADRHPC could save a great amount of time and worked automatically. Conclusion: The FADRHPC can simplify manipulation processes and make satisfied dentures.
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0.05),respectively.The fractured adheisive dentin surface was mainly a mixed failue mode.Conclusions:There is no significant difference in the bond strengths of each of the three bonding agents to ND and CAD.
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Objective: To comparative the mechanical properties of f our kinds of denture resin. Method: The impact strength, f lexural strength, flexural elastic modulus and Brinell hardness of four denture resin materials, Shanghai Shanhu(SH),Shanxi Changzhi(CZ), Luciton 199(LC) and Me liodent(MD), were measured in vitro and the stress-strain curve of each ma terial under flexural force was drawn. Results: The impact strength(kJ/m 2) of SH,CZ,LC and MD were 9.94?2.25,6.55?1.85,13.76?4.31 and 13.70?3.71; flexural strength (MPa) 75.27?3.24,78.88?7.66,80.47?3.27 and 7 6.72?3.14; flexural elastic modulus(GPa) 3.08? 0.15 ,2.96?0.10,2.63?0.11 a nd 2.56?0.12; Brinell hardness(kg/mm 2)24.15?1.34, 23.43 ? 1.65 ,20.86? 1.26 and 18.49?1.71,respectively. Conclusions: Comparativ ely speaking, SH and CZ are rigidit and brittle, LC is rigidit and sturdy, MD is tough and sturdy.
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Objective: To compare the fracture resistance of pulpless teeth restored with three types of post core.Methods: A total of 21 recently extracted sound upper incisors were randomly distributed into 3 groups. In group A the teeth were restored with prefabricated glass fiber post and composite core; in group B with custom cast titanium alloy post and core; and in group C with Ni Cr alloy dowel core. The size and shape of posts were identical in the 3 groups. All teeth were fully covered with Ni Cr alloy cast crown. Fracture resistance was measured by applying a point force at 130 degrees to the long axis of the teeth. Results: Mean fracture threshold was (276.6?15.1)N in group A, (394.7?29.1)N in group B and (373.4? 53.8 )N in group C. In group B and C, however, fracture always affected the tooth itself,whereas in group A,the core always failed first. Conclusion: Fiber reinforced composite(FRC) post may meet the clinical need, FRC post combined with composite core may prevent tooth root from fracture.
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Objective; To study the chromatic distribution of the chromatic value of Vitapan 3D- Master shade guide in color space. Methods: The color space of.Vitapan 3D-Master shade guide was measured and analyzed with CIE-1976-L* a* b. system and MINOLTA chromatic instrument (CR-321 ) under D65 standard source. Results: 26 shades of Vitapan 3D-Master could be divided into 5 groups according to the 3-dimensional layers. Inside the 2nd, 3th and 4th group, 6 shades distributed as equidistant ring circling M2 shade because their hue and chroma were different. The hue of L1. 5 and L2. 5 deflected to yellow, R1.5 and R2. 5 to red,that of M1-3 was intervenient. Conclusion: Vitapan 3D-Master shade guide is equidistant in color space and can be used more effeciently than Vitapan classical. Its chromatic value distribution perfectly and evenly covered color region of nature tooth.