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71.
颈动脉手术围术期预测脑侧支循环的方法评价   总被引:4,自引:3,他引:4  
To prediet the pateney of the cirele of Willis and cerebral ischemia during earotid artery surgery (ligation, resection, revascularization) is of rtmost importance both for the surgeons and the patients. Many methods have been proposed in the literature as simple and accurate means of evaluation the adequacy of cullateral hemispheric blood flow to compensate for a potentially resectable earoted artery. including Matas test, DSA, intraoperative measurement of stump pressure or back pressure, preoperative and intraoperative EEC monitoring, ocular plethysmograph (OPG),temporary balloon neelusion (TBO) alone or with single photon emission computerized tomography (SPECT). venon-enhanced computed tomography cerebral blood flow (Xe/CT CBF), and transcranial color Doppler (TCD). However, there is no single review and elinical studies showed that the combination of preoperative TBO and SPECT cerebral blood flow imaging significantly increases the safety of ICA/CCA resection, which can be used rontinely to predict the patients‘tolerance for earotid artery sacrifiee sithout developing neurologie deficits. Supported by Research Fund of the Ministry of Public Health (Grant No.96-1-340) and Sustentation Plan for Excellent Aeademic Leader of Shanghai Munieipality (Grant No.96XD14013).  相似文献   
72.
OBJECTIVES: The study series aims at testing the feasibility of the clinical application of tissue-engineered oral mucosa. The preliminary results were gathered over a period varying from 6 months to 12 years depending on the surgical method. METHODS: Tissue-engineered oral mucosa was used to cover defects in various surgical procedures like vestibuloplasty (n=42), freeing of the tongue (n=10), prelaminating the radial flap (n=5) and reconstruction of the urethra (n=16). In all interventions small samples of oral mucosa were harvested, cut into small pieces, resuspended in culture medium and seeded into a culture flask. Cultured keratinocytes were transferred onto membranes which then were used to cover mucosal defects in the oral cavity. RESULTS: To gain a graft of 15 cm(2) size a mucosa biopsy of 4-8 mm(2) and 40 ml autologous patients serum is needed. Tissue-engineered oral mucosa was applied successfully in all four surgical methods. Six months after transplantation a regular epithelial layering with a histological delimitation of the stratum, epithelial crest and a strong basal membrane appeared. According to the reception site the tissue engineered oral mucosa differentiated in several ways. CONCLUSION: Tissue-engineered oral mucosa fulfils the requirements for clinical routine. With view to healing time and outcome it does not appear to be superior to regular harvested oral mucosa transplants. Because of a smaller harvesting defect and primary wound closure at the actual operation site the patients' convenience is increased. Thus this method reduces morbidity and advances the quality of life.  相似文献   
73.
借助体外人工龋方法从形态和内部结构变化上探讨了氯化镧(La3+)对人牙釉质龋的影响。磨片光镜下显示La3+预处理阻抑龋病发展的作用不如氟化钠(F-),但La3+与F-先后预处理能明显减轻龋损程度。扫描电镜观察发现La3+及F-预处理均能在牙面形成覆盖物,但以La3+与F-先后预处理产生的覆盖物较致密且与牙面结合较紧密。电子探针分析显示La3+处理后釉质表层内钙(Ca2+)含量明显减少,而La3+显著增加,表明La3+能与Ca2+发生离子交换反应而进入釉质。这种牙面覆盖物的形成及La3+-Ca2+交换反应可能是La3+预处理能防龋的关键之一。  相似文献   
74.
OBJECTIVES: The purpose of the present parallel-design, controlled clinical trial was to evaluate the treatment outcome of periodontal furcation defects following flap debridement surgery (FDS) procedure in cigarette smokers compared to non-smokers. MATERIALS AND METHODS: After initial therapy, 31 systemically healthy subjects with moderate to advanced periodontitis, who presented at least one Class I or II molar furcation defect, were selected. Nineteen patients (mean age: 40.3 years, 15 males) were smokers (>or=10 cigarettes/day) and 12 patients (mean age: 44.8 years, 3 males) were non-smokers. Full-mouth plaque score (FMPS) and full-mouth bleeding score (FMBS), probing pocket depth (PPD), vertical clinical attachment level (v-CAL), and horizontal clinical attachment level (h-CAL) were assessed immediately before and 6 months following surgery. RESULTS: Overall, statistically significant v-CAL gain was observed in smokers (1.0 +/- 1.3 mm) and non-smokers (1.3+/-1.1 mm), the difference between groups being statistically significant (p=0.0003). In proximal furcation defects, v-CAL gain amounted to 2.3+/-0.7 mm in non-smokers as compared to 1.0+/-1.1 mm in smokers (p=0.0013). At 6 months postsurgery, non-smokers presented a greater h-CAL gain (1.3+/-1.1 mm) than smokers (0.6+/-1.0 mm), with a statistically significant difference between groups (p=0.0089). This trend was confirmed in both facial/lingual (1.4+/-1.0 versus 0.8+/-0.8 mm) and proximal furcation defects (1.2+/-1.3 versus 0.5+/-1.2 mm). The proportion of Class II furcations showing improvement to postsurgery Class I was 27.6% in smokers and 38.5% in non-smokers. After 6 months, 3.4% of presurgery Class I furcation defects in smokers showed complete closure, as compared to 27.8% in non-smokers. CONCLUSIONS: The results of the present study indicated that (1) FDS produced clinically and statistically significant PPD reduction, v-CAL gain, and h-CAL gain in Class I/II molar furcation defects, and (2) cigarette smokers exhibited a less favorable healing outcome following surgery in terms of both v-CAL and h-CAL gain.  相似文献   
75.
The overall accuracy of a novel surgical computer-aided navigation system for placement of endosseous implants was evaluated. Five dry cadaver mandibles were scanned using high resolution computed tomography (HRCT). The position of four interforaminal dental implants was planned on the computer screen and transferred to the cadaver mandibles using VISIT, a surgical navigation software developed at the Vienna General Hospital. The specimens were HRCT-scanned again to compare the position of the implants with the preoperative plan on reformatted slices after matching of the pre- and postoperative data sets using the mutual information technique. The overall accuracy was 0.96 +/- 0.72 mm (range 0.0-3.5 mm). No perforation of the mandibular cortex or damage to the mandibular canal occurred. We conclude that computer-aided implant surgery can reach a level of accuracy where further clinical developments are feasible.  相似文献   
76.
AIM: The purpose of the present study was to investigate the effectiveness of a regenerative procedure based on supra-crestal soft tissue preservation in association with combined autogenous bone (AB) graft/enamel matrix derivative (EMD) application in the treatment of deep periodontal intra-osseous defects. METHODS: Thirteen consecutively treated patients, seven females and six males, aged 30-65 years, three smokers, were included. A total of 15 deep, one- to two-wall intra-osseous defects were selected. Immediately before surgery and 6 months after surgery, pocket probing depth (PPD), clinical attachment level (CAL), and gingival recession (REC) were recorded. RESULTS: PPD amounted to 9.4+/-1.8 mm before surgery, and decreased to 4.7+/-1.2 mm post-surgery (p<0.0000). CAL varied from 10.5+/-2.0 mm pre-surgery to 6.2+/-1.7 mm post-surgery (p<0.0000), with CAL gain averaging 4.3+/-1.4 mm. Fourteen (93.3%) defects presented CAL gain >/=3 mm. REC change was 0.4+/-0.7 mm. CONCLUSIONS: Results from the present study indicated that a regenerative procedure based on supra-crestal soft tissue preservation and combined AB/EMD treatment leads to a clinically and statistically significant improvement of soft tissue conditions of deep periodontal intra-osseous defects.  相似文献   
77.
Ten fresh mandibles from adult sheep were stripped of all soft tissues and sectioned in the midline. We did sagittal split osteotomies and 5 mm advancement on all the 20 hemimandibles. Ten hemimandibles were fixed with three 2.0 mm x 13 mm titanium bicortical screws, and the other 10 were fixed with three 2.0 mm x 13 mm poly-l-lactic acid/polyglycolic acid (PLLA/PGA) bicortical screws in an inverted L pattern. All the hemimandibles were then mounted in a servohydraulic testing unit and tested to permanent deformation. Maximum forces that the mandibles resisted before breaking, maximum displacements, and the displacement values under 20, 60, 120, and 150 N were compared using the Mann-Whitney U-test. There were no significant differences in stability between the bones fixed with titanium and those fixed with resorbable screws.  相似文献   
78.

Introduction

Most clinical studies on the outcome of apical surgery concentrate on periapical healing based on radiographic and clinical characteristics (signs and symptoms). This study focuses on long-term changes in periodontal parameters after apical surgery.

Methods

Periodontal parameters (ie, probing depth [PD], level of gingival margin [GM], and calculated clinical attachment level [CAL]) were collected at baseline and at 1 and 5 years after apical surgery. Changes in PD, GM, and CAL were calculated over time and were also evaluated in relation to patient-, tooth-, and treatment-related covariables.

Results

One hundred eighty-six of 242 initially identified teeth could be evaluated. Significant changes in GM and CAL were observed at facial sites during the first year after surgery (mean recession of GM was 0.29 mm, mean CAL loss was 0.20 mm), but none of the periodontal parameters significantly changed between 1 and 5 years after apical surgery. With regard to covariables, the type of incision technique was found to be the major factor affecting changes in GM and CAL between baseline and 1 year after surgery. Age, smoking, and type of periapical healing were the variables influencing the periodontal parameters over the longer observation period of up to 5 years.

Conclusions

Patients should be informed about possible changes in periodontal parameters (gingival recession and loss of attachment) after apical surgery. The surgery itself appears to account for changes observed during the first year, whereas patient- and healing-related factors seem to affect periodontal changes seen thereafter.  相似文献   
79.
The purpose of this study was to evaluate the quantitative changes in tooth mobility before and after periodontal surgery using a tooth mobility tester. The tester was so designed as to be able to measure the cycle of sympathetic vibrations produced when a tooth was tapped with a impact hammer. Initially the degrees of tooth mobility, which were clinically classified from 0 to 3, were observed and the mode of mobility was assessed by the tester. Then, we examined the changes of tooth mobility after flap surgery. The following is a summary of findings.
1)  The coefficient of change in measurements had a tendency to decrease at the buccal site and the cervical site.
2)  At 1 week after flap surgery, the degree of tooth mobility was increased significantly.
3)  At the 6th week after surgery, tooth mobility had returned to the preoperative level.
4)  At 6 months after surgery, the mobility was decreased significantly compared to immediatery after surgery.
5)  The extent of bone absorption, probing pocket depth and clinical attachment level did not influence the postoperative changes of tooth mobility.
  相似文献   
80.

Objectives

The purpose of this study was to evaluate the in vitro effectiveness of a new bioglass-containing and two commercial desensitising toothpastes on dentinal tubule occlusion after citric acid challenge or artificial saliva (AS) immersion.

Methods

One hundred dentin discs from human third molars were used. Specimens were randomly divided into five groups (n = 20), Group 1: EDTA-treated dentin; Group 2: brushing with distilled water; Group 3: brushing with Novamin; Group 4: brushing with Sensodyne Freshmint; Group 5: brushing with Colgate Sensitive. In each group, samples were then equally split into two subgroups (n = 10) to test two post-treatments: 6% citric acid challenge or 24 h immersion in artificial saliva. Dentine permeability of each specimen was measured before and after each treatment using a hydrostatic device working at 20 cm H2O pressure. Data were analysed by two-way repeated measures ANOVA to determine if there were any significant differences within or between groups. Dentine morphology and surface deposits were observed by SEM.

Results

All three desensitising toothpastes significantly reduced dentine permeability and created precipitates on the treated dentine surfaces. Moreover, the reductions in dentine permeability showed partial recovery after a citric acid and artificial saliva immersion. Sensodyne showed significant resistant to acid attack and Novamin exhibited the lowest permeability after artificial saliva immersion for 24 h.

Conclusions

The application of the three toothpastes resulted in effective dentinal tubule occlusion. However, the new bioglass-containing toothpaste (Novamin) represented excellent occlusion effects after brushing treatment and AS immersion, while Sensodyne demonstrated more reduction in permeability when citric acid challenged.  相似文献   
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