Effect of liner and porcelain application on zirconia surface structure and composition

The purpose of this study was to determine if there is an effect of liner and porcelain application (layering and pressing techniques) on the surface of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP), which were exposed to permutations of liner, layered porcelain, and pressed porcelain. Scanning electron microscope (SEM)/energy dispersive spectroscope (EDS) was used to identify changes in composition and microstructure after removing liner and porcelain with hydrofluoric acid. Simulated aging was also conducted to determine the effect of liner and porcelain on low-temperature degradation. The control group had a typical equiaxed grain structure, referred to as unaffected. When covered with liner or porcelain, some areas changed in structure and composition and were termed affected. The frequency of affected structure decreased when liner was covered with either layered porcelain or pressed porcelain. There were statistical differences (Po0.05) in the composition between affected and unaffected for zirconium (layered porcelain with liner:affected=60%(0.8%) (m/m), unaffected=69%(4%), layered porcelain without liner:affected=59%(3%), unaffected=65%(3%)) and oxygen (layered porcelain with liner:affected=35%(2%), unaffected=26%(4%), layered porcelain without liner:affected=35%(3%), unaffected=30%(2%)). However, there were statistical differences (Po0.05) in the composition for zirconium and oxygen of the aged layered porcelain without liner only. The liner should not be used before porcelain application, especially when using the layering technique for zirconia restorations. Furthermore, pressing should be considered the technique of choice over layering.     

Effect of Self-adhesive Resin Cement and Tribochemical Treatment on Bond Strength to Zirconia

Aim To evaluate the interactive effects of different selfadhesive resin cements and tribochemical treatment on bond strength to zirconia.Methodology The following self-adhesive resin cements for bonding two zirconia blocks were evaluated:Maxcem (MA),Smartcem (SM),Rely X Unicem Aplicap (UN),Breeze (BR),Biscem (BI),Set (SE),and Clearfil SA luting (CL).The specimens were grouped according to conditioning as follows:Group 1,polishing with 600 grit polishing paper;Group 2,silica coating with 110 μm Al2O3 particles which modified with silica;and,Group 3,tribochemical treatment - silica coating + silanization.Specimens were stored in distilled water at 37℃ for 24 hours before testing shear bond strength.Results Silica coating and tribochemical treatment significantly increased the bond strength of the MA,UN,BR,BI,SE and CL to zirconia compared to #600 polishing.For both #600 polished and silica coating treatments,MDPcontaining self-adhesive resin cement CL had the highest bond strengths to zirconia.Conclusion Applying silica coating and tribochemical treatment improved the bond strength of self-adhesive resin cement to zirconia,especially for CL.     

鼻腔扩容术对鼻塞伴OSAHS患者的主客观症状的影响

目的探讨鼻腔扩容术对伴有鼻塞的阻塞性睡眠呼吸暂停低通气综合征(OSAHS)的主客观症状的影响,为鼻腔扩容术对鼻塞伴OSAHS的患者治疗提供有效的临床依据。方法选择69例伴有鼻塞的OSAHS患者,针对病变的鼻中隔、下鼻甲、中鼻甲、钩突、筛泡等不同部位的病变进行个体化的处理。根据呼吸暂停低通气指数(AHI)及最低动脉血氧饱和度(LSaO2)分为三组:轻度、中度与重度组。通过比较患者手术前后多导睡眠检测(PSG)结果及鼻塞视觉模拟评分量表(VAS)、Epworth嗜睡量表(ESS)、患者鼾声问卷(SS)评分,分析鼻腔扩容术对鼻塞伴OSAHS患者的主客观症状的影响。结果术后6个月随访显示,其中轻度OSAHS患者的AHI、LSaO2及平均动脉氧饱和度(MSaO2)有所升高(P<0.05),VAS、ESS及SS评分都有所降低(P<0.05)。中度OSAHS患者的PSG相关检测指标均无明显变化(P>0.05),VAS、ESS及SS评分有所降低(P均<0.05)。重度患者除VAS及ESS评分有所降低(P<0.05),PSG相关客观指标及SS评分均无明显变化(P>O.05)。结论鼻腔扩容手术可以改善鼻塞为主的OSAHS患者的鼻塞、睡眠打鼾及白天嗜睡等主观症状,对轻度OSAHS患者的疗效优于中重度OSAHS。对鼻塞伴OSAHS患者的治疗有重要的临床意义。     

上气道多平面扩容术对重度阻塞性睡眠呼吸暂停低通气综合征患者嗓音的影响

目的：探讨上气道多平面扩容术对重度阻塞性睡眠呼吸暂停低通气综合征（OSAHS）患者嗓音的影响。方法：对26例重度OSAHS患者于上气道多平面扩容术前后,分别应用针对嗓音相关的主观调查问卷和嗓音频谱分析软件进行客观统计学分析。结果：主观调查问卷结果显示,26例患者上气道多平面扩容术后4例（15．4％）出现短时间的轻度腭咽闭合功能不全所致的鼻腔反流现象,均于术后1周内消失;3例（11．5%）术后发声有轻度鼻音增高,尤以术后1周内较明显而后逐渐消失;2例（7．7％）扁桃体Ⅲ度肥大者诉发声清晰度较前提高,原有轻微含糖音消失;总体评价是嗓音障碍指数量表、嗓音相关生活质量量表评分手术前后均无明显变化（P〉0．05）。嗓音客观参数基频F0和F1、F2、F3及F4共振峰频率手术前后均无统计学差异。结论：上气道多平面扩容术能够解除重度OSAHS患者上气道的阻塞性因素,同时进行鼻腔和咽腔的塑形,在一定程度上改变了声道共鸣腔,但对重度OSAHS患者嗓音的主观心理听觉评估无明显变化,嗓音客观参数基频F0和F1、F2、F3及F4四个共振峰频率均无明显的变化。     

植入年龄对婴幼儿人工耳蜗植入患者早期言语可懂度的影响

目的本研究评估使用人工耳蜗的婴幼儿患者早期言语可懂度发育并探讨植入年龄对言语可懂度的影响,为患儿的听力言语康复提供指导。方法共有272例极重度语前聋人工耳蜗植入婴幼儿参加本次研究。手术年龄9～36个月,平均（21±7）个月。根据植入年龄将患儿分为3个组：A组小于18个月,B组为19～24个月,C组为25～36个月。使用言语可懂度分级（speech intelligibility rating,SIR）问卷在术前及术后开机后1、3、6、9个月和1年时对患儿进行评估。结果患儿SIR平均得分在术前、术后开机后1、3、6、9个月和1年之间的差异有显著性。3个组患儿SIR平均得分在术后开机后3个月、6个月之间的差异有显著性,在术前、术后开机后1个月、9个月、1年之间的差异无显著性。结论极重度语前聋人工耳蜗植入婴幼儿患者的言语可懂度在术后1年内有显著提高。植入年龄对婴幼儿人工耳蜗患者术后早期言语可懂度发育没有显著影响。     

不同手术方式对鼻咽癌放疗后慢性鼻-鼻窦炎症状控制的影响

目的　探讨不同手术方式对鼻咽癌放疗后慢性鼻-鼻窦炎（chronic rhinosinusitis,CRS）症状控制的影响。方法　68例鼻咽癌放疗后CRS患者被分成2组,分别行上颌窦自然口扩大（组1）以及上颌窦口扩大联合下鼻道开窗（组2）为特征的鼻内镜手术,分析这些患者治疗前、后视觉模拟量表（visual analogue scale,VAS）评分的特点及两组治疗后症状控制率的差异。结果　组2黏脓性鼻涕和面部胀痛症状控制率及VAS评分差异有统计学意义,前者优于后者。结论　以上颌窦自然口扩大联合下鼻道开窗术为主的综合治疗方案对于鼻咽癌放疗后CRS,上颌窦病变较重、黏脓性鼻涕和面部胀痛症状的VAS评分较高的患者控制较好。