Disinfection of implant abutment connection using antimicrobial photodynamic therapy and 0.2% chlorhexidine gel applications immediately before prosthesis delivery: Clinical and radiographic status at 1-year of follow-up

ObjectiveThe aim of this 1-year follow-up randomized control trial was to compare the clinicoradiographic status of implants that were disinfected with antimicrobial photodynamic therapy (aPDT) and 0.2% chlorhexidine gel immediately before prosthesis delivery.MethodsForty-five partially edentulous patients with implants placed in the region of missing mandibular first molars and a history of periodontal diseases were included. Immediately before prosthesis delivery, patients were divided into three groups. In groups 1 and 2, implant abutment disinfection (IAD) was performed using aPDT and 0.2% chlorhexidine immediately before prosthesis delivery. In Group-3, IAD was performed using a steaming protocol. Peri-implant modified plaque index (mPI), modified gingival index (mGI), probing depth (PD) and crestal bone loss (CBL) were assessed at 1 year of follow-up. Power analysis was done and group comparisons were done. Logistic regression analysis was done to corelate clinical parameters with demographic variables. P<0.01 was considered statistically significant.ResultsIn total, 15, 15, and 15 implants were present among patients in groups 1, 2 and 3, respectively. There was no statistically significant difference in peri-implant mPI, mBoP, PD and CBL in all groups (Table 2). None of the patients had periodontal disease and there was no statistically significant correlation between peri-implant clinicoradiographic parameters with age, toothbrushing and flossing habits, and duration of implants in function. Eighty percent, 86.7% and 100% individuals in groups 1, 2 and 3, respectively reported that they were brushing teeth twice daily. Flossing of interproximal spaces once daily was reported by 66.7%, 73.3% and 66.7% individuals in groups 1, 2 and 3, respectively.ConclusionAs long as oral hygiene is stringently maintained after implant prosthesis delivery, IAD can be performed using aPDT, 0.2% CHX gel or steam-disinfection.     

单个后牙缺失伴远端基牙倾斜的树脂黏结固定桥修复研究

目的 观察树脂黏结固定桥(RBFPD)修复下颌单个后牙缺失合并桥基牙倾斜患者的临床效果,并总结其适应证和设计特点.方法 选择2002-2003年在解放军总医院口腔科就诊的典型下颌单个后牙缺失、远端基牙近中倾斜的患者18例,所有患者基牙倾斜度不超过50°,基牙无明显松动,牙周无异常.根据基牙倾斜和模型观测结果,设计(牙合)支托和固位体的位置和形态,义齿选择普通钛合金烤瓷或钻铬合金烤瓷修复,并在修复体完成后进行5年随访.随访时进行临床检查、X线片检查并询问患者主观感受.结果 远端倾斜基牙平均倾斜33°.随访5年后,2例修复病例修复体脱落,其余义齿功能良好,牙周无明显炎症.基牙以及桥体下方牙龈无明显红肿,X线片示基牙牙周间隙无异常,患者对于修复体的外观及使用情况满意.5年期间修复体的成功率为88.9%.结论 对于伴有基牙倾斜的单个后牙缺失,采用树脂黏结固定桥进行修复的效果可靠,并具有磨牙少、基牙无需进行根管治疗等优点.     

改良型富血小板纤维蛋白预防下颌阻生智齿拔除术后并发症的效果

 目的 探讨应用改良型富血小板纤维蛋白(advanced platelet-rich fibrin,A-PRF)预防下颌阻生智齿拔除术后并发症的效果。方法 选取20例需拔除双侧下颌智齿患者,每名患者随机筛选一侧牙槽窝,行A-PRF填充(试验组);另一侧行常规缝合处理(对照组)。比较术后1、7d两侧拔牙窝疼痛程度、疼痛发生率及软组织肿胀程度,同时评价不同处理方式后张口度及术后3个月第二磨牙远中牙周袋深度。结果 试验组牙槽窝术后1d后疼痛分级为4.25,低于对照组的6.20(P<0.05),且疼痛发生比例低于对照组牙槽窝。随着时间延长,两侧牙槽窝的术后疼痛级别都显著下降。拔牙后1 d,试验组牙槽窝肿胀度为(0.59±0.09)cm,张口度为(3.79±1.25)cm,皆显著低于对照组(P<0.05);7 d后对照组和试验组两侧肿胀程度分别为(0.025±0.09)cm和(0.013±0.07)cm,两组无统计学差异;术后3个月两侧第二磨牙远中牙周袋探诊深度分别为(4.61±0.27)mm和(3.39±0.29)mm(P<0.05)。结论 A-PRF的应用可以有效减少下颌阻生智齿拔牙术后并发症的发生。     

Impact of various luting cements on the fixed dentures bonding strength

BACKGROUND/AIM: Various luting cements are used to fix dental crowns to prepared teeth, and should provide an adhesive bond to the tooth structure giving reliable retention. The aim of this study was to establish in vitro which type of the tested luting cement provided the strongest adhesive bond of the prepared teeth to the fixed denture. METHODS: Testing was carried out on the sample of 100 intact human premolars extracted for orthodontic reasons. The preparation of the teeth was performed by a heavy-duty machine. The surfaces of the prepared teeth were mathematically calculated. Dental crowns from the Nickel-Chromium-Molybenum (Ni-Cr-Mo) alloy were made in a standard fashion, and fixed to prepared teeth (two samples of each group) with 5 different types of luting cements. The strength of force applyed to separate the cast crowns from the prepared teeth was measured by an electronic dynamometer, after 7 days. RESULTS: The obtained results revealed the connection between the type of luting cement and the values of retention power. The best adhesive bond under the constant convergence angle of the prepared teeth was provided by the resin cement. CONCLUSION: When choosing a luting cement for fixing dental crowns to prepared teeth, the advantage should be given to the resin cement in case the glassionomers are not available.     

Hemangioblastomas of the lower spinal region: report of four cases with preoperative embolization and review of the literature

BACKGROUND AND PURPOSE: Hemangioblastomas (HBs) are rare lesions accounting for 1-5% of all spinal cord tumors. Seventy-five percent of spinal HBs are intramedullary. Lesions of the conus medullaris and the cauda equina are uncommon, and the filum terminale location is very rare. HBs of the lower spinal region are highly vascular tumors requiring surgery that is potentially complicated by excessive bleeding. In the literature, there are few reports concerning preoperative embolization of HBs, and only few cases are reported in spinal location. Presurgical embolization of HBs located in the lower spinal region has not been described. Although lower spinal HBs are predominantly fed by the anterior spinal artery (ASA), embolization of these lesions is possible and can reduce tumor vascular supply, thus facilitating surgery. We report our experience in four rare cases of solitary HBs occurring in the lower spinal region. METHODS: Clinical charts and radiologic studies of four patients with a preoperatively embolized HB of the lower spinal region were retrospectively reviewed. The lesions were located in the conus medullaris in one case, at the level of the cauda equina in another, and in the filum terminale in two. In the conus medullaris case, the neoplasm was associated with a syrinx. In three patients, the HB was sporadic, while the patient with the HB of the cauda equina had Von Hippel-Lindau disease. Devascularization of the tumor was performed through the ASA in all cases and also through the posterior spinal artery in one by using non reabsorbable calibrated microspheres in three cases and polyvinyl alcohol particles in the other one. RESULTS: Embolization caused no permanent complications, although one patient with a cauda equina HB mildly worsened after the endovascular procedure but recovered before surgery. At surgery, the tumor was completely removed in all cases. Blood loss was reported to be less than usually observed (100, 200, 200, and 400 mL). In addition, manipulation and removal of the tumor was reported to be easy in three of four tumors. Histologic examination confirmed the diagnosis. At 1-year postsurgical follow-up, two patient recovered completely from neurologic deficits, and two showed significant recovery. No tumor recurred during a follow-up period of 1-6 years (mean, 3.5 years). CONCLUSION: Our results indicate that preoperative embolization of HBs of the lower spinal region is an useful procedure in aiding surgical resection of these highly vascular tumors. With a meticulous technique, embolization can be performed through the ASA.     

MRI in Lyme disease of the spinal cord

We report a case of Lyme myelitis in a 31-year-old man, presenting with a conus medullaris syndrome. MRI demonstrated contrast enhancement on the pial surface of the lower thoracic cord and conus medullaris. Elevated blood immunoglobulins and IgM antibodies against Borrelia burgdorferi in the cerebrospinal fluid (CSF) were found. Leptomeningitis may be the first stage of spinal infection in Lyme disease, preceding parenchymal infection leading to myelitis. Vasculitis is probably the major mechanism. MRI findings are nonspecific and the diagnosis is given by serum and CSF analyses. Early treatment with antibiotics and high doses steroids may result in complete recovery, as in this case. Received: 29 December 1999 Accepted: 31 January 2000     

Measurements of tooth length in panoramic radiographs. 1. The use of indicators.

The aim of this study was to investigate both the actual and the radiographic tooth lengths of the maxillary first molar and second premolar and the mandibular premolars in panoramic radiographs. The actual length of 64 extracted teeth was measured. Steel balls were then attached to the cusp and apex and the teeth embedded in plastic moulds. Each pair of plaster casts with their set of teeth was radiographed with an Orthopantomograph twice at an interval of 1 month. The actual and the radiographic tooth length was measured twice by one observer. The mean tooth length of the molar was shorter than that of the premolars. The mean difference between the repeated measurements of the actual tooth length was small and ranged between 0.47 and 1.16% of the tooth length. The mean difference between repeated measurements of the radiographic tooth length was also small, with a method error of 0.13-0.21 mm. The vertical magnification in panoramic radiography was lower for mandibular premolars (13-15%) than for the maxillary second premolar and first molar (17-28%). The palatal root of the maxillary first molar had the highest vertical magnification (28%). Following the second set of radiographs, the mean difference between the measurements was small, except for the palatal root of the maxillary first molar (P < 0.001). Radiographic measurements of this root should therefore be used with caution. The results for the other roots examined indicate that these could be measured with high reproducibility.     

螺旋断层放疗在分段全身照射中上下靶区衔接处剂量分布的影响因素研究

目的 选取10例身高在120.0 cm左右的急性白血病患者分上下两段行螺旋断层治疗（HT）实现全身照射（TBI）,通过分析衔接处靶区剂量分布的变化情况,寻找最佳靶区间隔距离所对应的计划设计参数。方法 选取的研究对象使用德国Siemens公司定位CT获得层厚为5 mm的全身图像,同时在髌骨上方10 cm处放置铅丝,作为上下两段靶区的分割线。在美国瓦里安Eclipse 13.5医生工作站进行靶区和危及器官的勾画,其中上下靶区在铅丝分割处依次分别内收不同距离,然后传至HT计划工作站进行计划设计,其中射野宽度（FW）分别选择5.0、2.5、1.0 cm,螺距分别选择0.430与0.287,调制因子1.8,剂量计算网格（最精细：0.195 cm×0.195 cm）,其余计划参数都保持一致。将其分两段照射的上下靶区依据不同参数进行计划设计,并将设计好的不同参数的计划分别对应叠加在一起进行分析衔接处靶区剂量分布的变化情况。结果 通过比较不同螺距和射野宽度所对应不同间隔距离的衔接处靶区的剂量分布,发现只有射野宽度才影响衔接处靶区的剂量分布：当射野宽度为5.0 cm时,靶区间隔距离为5.0 cm在衔接处的剂量分布最佳;同理当射野宽度为2.5和1.0 cm时,靶区间隔距离分别为2.0和1.0 cm时最佳,即衔接处靶区的最佳剂量分布所对应的间隔距离与射野宽度保持一致。而螺距对衔接处靶区剂量和总治疗时间比值没有影响,总治疗时间长度与射野宽度保持一致反比关系。结论 对于HT进行分段式TBI治疗时,采用如上的计划设计参数,同时靶区勾画时间隔距离与射野宽度保持一致,能保证在进行分段TBI治疗时衔接处靶区不会出现剂量冷热点,确保了治疗的精确与安全。在实际临床治疗过程中,为达到治疗效果与效率的平衡,需要选择合适的计划参数。     

Placement of venous stents: clinical experience with a self-expanding prosthesis.

A self-expanding vascular prosthesis was used to treat 20 venous stenoses or occlusions in 13 patients. The lesions were caused by tumor (n = 5), postoperative fibrous scars (n = 2), and chronic hemodialysis fistulas (n = 13). Follow-up ranged between 6 weeks and 53 months (mean follow-up, 14.9 months). Acute occlusion occurred in two stents, one within a tumor stenosis and one in a dialysis shunt after 3 days and 2 days, respectively. Balloon angioplasty, thrombolysis, and aspiration in the first case and balloon angioplasty and thrombolysis in the second case successfully restored patency. Definite occlusion occurred in these two patients after 8 weeks and 5 months, respectively. Ten secondary interventions were performed in three patients with 10 restenoses who had stenotic arm veins in chronic hemodialysis at presentation. Five of seven patients who received treatment for stenoses associated with hemodialysis underwent successful kidney transplantation 5-27 months after placement of vascular stents. Both patients who received treatment for benign strictures had patent stents at follow-up examinations performed at 45 and 53 months, respectively. Four of five stents placed for malignant stenoses were patent at venography (n = 3) or autopsy (n = 1).     

In vitro comparison of conventional film and direct digital imaging in the detection of approximal caries

OBJECTIVES: To compare the diagnostic accuracy of conventional film, unenhanced direct digital and inversion grayscale direct digital imaging in the detection of approximal caries. METHODS: 150 approximal surfaces of extracted permanent molars and premolars were selected for the study on the basis of varying lesion depth. The teeth were radiographed using Ektaspeed Plus film; digital images were made with a Schick CMOS-APS sensor. 7 examiners evaluated 58 randomized images of each modality. Histological sectioning of the teeth was used to verify the presence and extent of decay. RESULTS: No significant difference was found between the diagnostic accuracies of the three imaging modalities (P=0.226). Analysis of the diagnostic accuracy of the three modalities on lesion depth showed no statistically significant interaction; however, the main effect of the lesion depth was significant (P<0.001, eta(2)=0.936). CONCLUSIONS: The overall diagnostic accuracy of the three modalities in the detection of approximal carious lesions was comparable. All three modalities performed poorly in the detection of enamel lesions.     

Measurements of tooth length in panoramic radiographs. 2: Observer performance.

Observer performance in tooth-length measurements in panoramic radiography has been examined. Sixty-four teeth, evenly distributed between maxillary first molars, second premolars and mandibular first and second premolars, were fixed in plastic moulds. Each cast was radiographed with an Orthopantomograph, twice with steel balls indicating the cusps and apices of the teeth and once without them. One observer measured the radiographic tooth length twice in both radiographs with indicators in order to estimate the true radiographic tooth length and the repositioning error, and twice in the radiographs without indicators. Seven other observers measured the tooth length on the radiographs without indicators, twice applying their own criteria and twice using defined criteria. The accuracy of the tooth-length measurements was calculated by comparing the true radiographic tooth length with the measurements of the seven observers. The intra-observer variation was defined as the difference between two measurements on the same radiograph. The accuracy and the precision of the tooth-length measurements were highly influenced by the observer performance. The mean radiographic tooth length of the seven observers was closer to the true radiographic tooth length when the observers applied the defined criteria. The inter- and intra-observer variation was higher for the measurements of the maxillary teeth (0.3-1.9 mm) compared with the mandibular teeth (0.3-0.9 mm) for most observers. The highest intra-observer variation was found for the palatal root of the maxillary first molar. The intra-observer variation of four observers decreased somewhat when the defined criteria were used; for the other three observers, however, the variation increased.(ABSTRACT TRUNCATED AT 250 WORDS)     

DTI对脊髓圆锥与终丝界限区分的初步研究

目的 探讨DTI脊髓成像在区分脊髓圆锥与终丝界限的可行性及临床意义.方法 选取10例腰椎MRI检查患者,行常规腰椎矢状位T1WI,T2WI检查,轴位T2WI检查,同时行T11～L4椎体水平脊髓EPI序列DTI成像.结果 DTI能清晰显示脊髓及圆锥的形态及走行,终丝未见显影,脊髓圆锥位于L1椎体下缘及L2椎体上缘,与常规MRI检查二者有较好的一致性.脊髓的ADC值低于脑脊液,FA值高于脑脊液.结论 脊髓DTI能区分脊髓圆锥与终丝的界限.     

Glioblastoma multiforme of the conus medullaris in a child: description of a case and literature review

We describe a case of glioblastoma multiforme of the conus medullaris in a child. MR imaging showed at the T12-L1 level an intramedullary mass with signal alteration, with only two nodules of contrast enhancement. The finding was consistent with astrocytoma. Pathologic evaluation was consistent with glioblastoma multiforme. Nine months after the surgical treatment, the patient showed leptomeningeal recurrence. This case appears to be unusual for both the hysto-type and the nonspecific MR imaging features.     

正畸牵引在前牙龈下牙折的临床应用

目的分析与探讨正畸颌向牵引对龈下牙折的临床效果。方法龈下牙折患者17例,共18颗患牙,断端均位于龈缘下2~5 mm。经完善的根管治疗后2周,黏接方丝托槽开始正畸牵引,使其达到直接修复高度,牵引后保持3个月行修复治疗。测量分析不同阶段根尖片上断根根尖区相对骨密度改变。结果 18颗患牙经正畸牵引1~2个月后,断端伸长2~5 mm,保持3个月后,无明显松动,通过烤瓷冠修复均达到理想的美观效果。牵引后保持3个月,根尖区骨密度基本达到正常水平。半年后随访,牙周正常未见异常及复发。结论正畸牵引可有效用于龈下牙折病人的修复前牙根牵引,疗效可靠。     

Technetium-99m sestamibi brain SPECT in the follow-up of glioma for evaluation of response to chemotherapy: first results

The initial treatment of high-grade glioma often consists of surgery and radiation therapy. Chemotherapy is used in cases of recurrence or after incomplete surgery. Because of the many potential serious side-effects of chemotherapy, early tumour response evaluation is necessary to enable clinicians to adapt the treatment. However, response monitoring with computed tomography (CT) or magnetic resonance imaging (MRI) is often difficult. The aim of this study was to assess the value of repeated technetium-99m methoxyisobutylisonitrile (^99mTc-MIBI) single-photon emission computerised tomography (SPECT) for this purpose. Fifteen patients with malignant glioma were investigated with MIBI SPECT. Imaging was performed 1 h after the intravenous injection of 555 MBq of ^99mTc-MIBI, using a dedicated SPECT system (Tomomatic 564, Medimatic, Denmark). Overall, 57 investigations were performed. A MIBI uptake index was computed as the ratio of counts in the lesion to those in the contralateral region. Previous study had shown a cut-off value of 2.0 to be appropriate. SPECT indices were compared with neurological evaluation, CT or MRI. This assessment was performed every 4 months during and after the treatment. Six patients showed an increased MIBI index associated with clinical or radiological progression of disease during chemotherapy. After an initial response to therapy, three patients showed an increased MIBI index despite chemotherapy, demonstrating secondary resistance to therapy. Six patients showed a decreased MIBI index, demonstrating a good response to therapy. The first nine patients died shortly after the last SPECT scan (average duration of survival, 4 months). The therapeutic protocol was modified in six cases, but successfully so in only two. In some cases, tumour progression was diagnosed earlier with SPECT than on the basis of clinical or MRI signs. Early response or resistance to chemotherapy is detectable by^99mTc-MIBI SPECT. Therefore this functional imaging modality could be considered as a valuable tool to permit effective adaptation of the therapeutic regimen in patients treated for recurrent high-grade glioma.     

金属烤瓷修复体在前牙美容修复中的应用

目的　探讨金属烤瓷修复体在前牙美容修复中的临床应用范畴 ,及在某些特殊情况下如何达到最佳修复效果。方法　确定适应证、比色、预备基牙、取模、戴牙。结果　 30 9例金属烤瓷修复的前牙 ,经 3月～ 4年观察 ,1例因牙根纵折失败 ,其余疗效满意。结论　金属烤瓷修复体在满足适应证的情况下 ,在前牙美容修复中应用广泛 ,疗效满意。     

Serial change of TL/BMIPP dual SPECT myocardial scintigram in patients with acute myocardial infarction; meaning of chronic mismatch phenomenon]

This study was aimed to elucidate the serial changes and clinical significance of accumulation mismatch with TL and BMIPP dual SPECT myocardial scintigraphy during 6 months in patients with acute myocardial infarction (AMI). The dual SPECT scintigraphy was performed at one, three and six months after onset of AMI in 46 patients who underwent reperfusion therapy. Long axis fractional shortening in infarct-related area and left ventricular end-diastolic volume index (LVEDVI) were measured by left ventriculography performed immediately after reperfusion and at one, six months after onset of AMI. The patients were divided into two groups: those with mismatch (Group (+)) and those without (Group (-)) at one month after reperfusion. Group (+) was subdivided into three groups according to duration of persistence of mismatch; one month persistence (1 M), three months (3 M) and six months (6 M). Improvement of wall motion abnormality (WMA) in infarct-related area was seen at one month after reperfusion in group 1 M and group 3 M, while group 6 M showed no apparent change in WMA throughout the study period. LVEDI did not change at six months after reperfusion in group 1 M and 3 M, while significant increase was seen in group 6 M. It is concluded that the case with disappearance of mismatch between TL and BMIPP until three months after reperfusion indicates myocardial stunning while in the case with long-standing mismatch left ventricular remodeling is suggested.     

Impacted teeth in the maxilla: usefulness of 3D Dental-CT for preoperative evaluation

OBJECTIVE: To compare the shapes of roots of impacted teeth shown in three-dimensional computed tomographic images (3D Dental-computed tomography (CT) images) and plain radiographs and to determine whether 3D Dental-CT images are useful for examination before performing an operation for extraction of a maxillary impacted tooth. METHODS AND PATIENTS: Images obtained from patients who had impacted teeth in the maxilla, including impacted mesial supernumerary teeth in 13 patients, impacted incisors in two patients, impacted canines in 11 patients, impacted premolars in four patients and impacted molars in three patients, were used in this study. In all patients, plain radiographs and 3D Dental-CT images were retrospectively reviewed by an oral radiologist for evidence of root dilaceration before operations to extract the impacted teeth were performed. The findings in the images were compared with intraoperative findings in all cases. RESULTS: The mean specificity and sensitivity of plain radiographs were 95 and 8%, respectively, while those of 3D Dental-CT images were 100 and 77%, respectively. There was a statistically significant (P<0.01) difference between the depiction capabilities of plain radiographs and 3D Dental-CT images with regard to dilacerations of roots of impacted teeth. DISCUSSION AND CONCLUSION: CT may enable radiologists to make a quick and accurate diagnosis of tooth impaction. 3D Dental-CT images are useful for determining the root shape of an impacted tooth in the maxilla.     

Positional changes of the lower and upper anterior teeth after surgical correction of mandibular prognathism

BACKGROUND/AIM: To establish the influence of surgical corrections of mandibular prognathism upon the position of the lower and upper anterior teeth (incisors). METHODS: The changes in position of the lower and upper anterior teeth (incisors) after the surgical correction of mandibular prognathism were analyzed by means of x-ray craniometry in 183 patients (female: n = 110, male: n = 73) in which the correction had been made in accordance with the principles of sagital osteotomy of the mandibular ramus. There were 4 angular and 2 linear parameters determined in the pre- and postoperative tele-x-ray-pictures. The changes of these parameters were tested by means of the parametric statistic tests. RESULTS: The performed surgical procedures did not cause statistically significant changes in the angular parameters. The changes of both linear parameters were thought highly statistically significant. CONCLUSION: Under the influence of the performed surgical procedures no changes were found in the position of anterior teeth (incisors) in relation to SN and the mandibular plane. They were actually moved along with the medium fragment of the lower jaw and that fragment was moved linearly backwards along the occlusal plane with a practically insignificant rotation in the cranial direction.     

Venous prosthetic valves. The first step toward an investigation in the canine model

Bioprosthetic valves were surgically placed in the inferior vena cava of four canines as a first step in the investigation of prosthetic valves for the treatment of nonobstructive chronic venous stasis. Valve patency and thrombus formation involving either the valve or the IVC was evaluated by serial follow-up inferior vena cavagrams in each canine. No thrombus occurred in any of the canines as observed at six months in two canines and eight months in two canines. The ultimate goal of this and other ongoing investigations is to develop a valvular prosthesis which may be placed into the venous system for the management of nonobstructive chronic venous stasis.