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1.
JDR Clin Trans Res ; : 23800844241246198, 2024 May 10.
Article En | MEDLINE | ID: mdl-38733110

KNOWLEDGE TRANSFER STATEMENT: Obstructive sleep apnea has been proven to have a great negative impact on patients, and the relationship between sleep apnea and dental caries is still inconclusive. Our study shows that patients with sleep apnea and those older than 45 y have a significant risk of dental caries.

2.
J Neurosurg Case Lessons ; 5(15)2023 Apr 10.
Article En | MEDLINE | ID: mdl-37039291

BACKGROUND: Dural arteriovenous fistulas (dAVFs) are aberrant vascular communications between meningeal arteries and venous sinuses or cortical veins. dAVF pathogenesis is incompletely understood; however, formation likely occurs as a result of angioneogensis. OBSERVATIONS: A 78-year-old man presented after trauma with basal and cortical subarachnoid hemorrhage (SAH). Computed tomography revealed a parietal bone fracture overlying the superior sagittal sinus (SSS). Catheter angiography performed within 24 hours of the injury demonstrated an SSS dAVF supplied by the middle meningeal artery, adjacent to the fracture. LESSONS: The authors present the case of an acute traumatic dAVF adjacent to a calvarial fracture. In this case, the authors proprose that the underlying pathogenesis is suggestive of direct vessel injury rather than the pathway commonly associated with this pathology.

3.
J Clin Neurosci ; 80: 238-241, 2020 Oct.
Article En | MEDLINE | ID: mdl-33099353

Colloid cysts are uncommon, intracranial lesions frequently arising from the anterior aspect of the third ventricle. Rarely a cyst presents greater than 30 mm diameter as a giant colloid cyst. This case reports a patient with a giant colloid cyst occupying a cavum septum pellucidum et vergae. The clinical and operative significance of this anatomical variation is discussed and the giant colloid cyst literature reviewed.


Colloid Cysts/diagnostic imaging , Colloid Cysts/surgery , Septum Pellucidum/diagnostic imaging , Septum Pellucidum/surgery , Third Ventricle/diagnostic imaging , Third Ventricle/surgery , Adult , Humans , Male
4.
Br Dent J ; 222(1): 21-25, 2017 Jan 13.
Article En | MEDLINE | ID: mdl-28084388

Objectives To evaluate long-term outcomes of modified crown lengthening procedures for crown-root fractured teeth, and to analyse factors that affect the periodontal health of the treated teeth.Methods The present study retrospectively analysed data from 22 patients (13 males and 9 females) who had presented with crown-root fractured teeth and received modified crown lengthening procedures combined with crown restoration for ≥13 months. In total, 26 crown-root fractured teeth were treated and examined for plaque index, probing depth, bleeding index, bleeding on probing, mobility and the crown margin location. The contralateral tooth and ipsilateral teeth mesial and distal to the treated tooth were used as controls. Data were assessed descriptively or analysed statistically with Mann-Whitney-U test at α=0.05.Results Recorded periodontal indices revealed stable periodontal status in 25 of 26 treated teeth with the mean values for aesthetic and functional VAS scores at 9.5. A negative correlation was observed between the subgingival crown margin location and the bleeding index.Conclusions The modified crown lengthening procedure is a feasible and minimally invasive therapeutic option for management of crown-root fractured cases.


Crown Lengthening , Periodontal Diseases/etiology , Tooth Crown/injuries , Tooth Fractures/surgery , Tooth Root/injuries , Adult , Crown Lengthening/methods , Dental Plaque Index , Female , Humans , Male , Middle Aged , Periodontal Index , Retrospective Studies , Tooth Crown/surgery , Tooth Root/surgery , Young Adult
5.
Andrology ; 5(1): 58-62, 2017 01.
Article En | MEDLINE | ID: mdl-27636882

Recent studies have focused on the relationship between nocturia and serum testosterone because testosterone is thought to be an important factor of prostate growth. However, it remains unclear whether altered serum concentrations of testosterone is associated with an increased risk of nocturia because patients who were taking diuretics or who had a large prostate, which may precipitate nocturia, were not excluded from most previous studies. We analyzed the clinical records of 596 non-benign prostatic enlargement (BPE) male patients to explore the relationship between serum total testosterone and nocturia. All patients were evaluated using a serum prostate-specific antigen (PSA) assay, measurement of serum total testosterone, transrectal ultrasonography, uroflowmetry, and a compilation of the International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF) questionnaires. Nocturia was defined as ≥2 nocturnal voiding episodes. The number of nocturia episodes was assessed using IPSS question 7. To evaluate the effect of serum testosterone on nocturia, multivariate regression analysis was performed including the covariates of age, IPSS, IIEF score, body mass index, PSA, prostate volume, and maximal urine flow rate. Based on multivariate linear analysis, serum testosterone level was not significantly associated with the severity of nocturia. However, with regard to the relationship between prevalence of nocturia and serum testosterone, prevalence of nocturia was significantly positively associated with age (OR = 1.048, p = 0.005), total IPSS (OR = 1.217, p < 0.001), and testosterone level (OR = 1.150, p = 0.041). Therefore, in men without an enlarged prostate, testosterone may play an opposing role in the etiology of nocturia.


Nocturia/blood , Prostatic Hyperplasia/blood , Testosterone/blood , Adult , Humans , Male , Middle Aged , Nocturia/complications , Prostate , Prostatic Hyperplasia/complications , Prostatic Hyperplasia/pathology
6.
East Asian Arch Psychiatry ; 26(4): 121-8, 2016 Dec.
Article En | MEDLINE | ID: mdl-28053279

OBJECTIVES: To evaluate the prevalence of affective disorders and identify their associated factors among Chinese mothers of preschool children diagnosed with autism spectrum disorders. METHODS: This cross-sectional study was conducted at the Autism Spectrum Disorders Multidisciplinary Clinic of the United Christian Hospital from August 2012 to June 2013. All mothers of a consecutive series of preschool children diagnosed with autism spectrum disorders at their first visit to the clinic were recruited. Information regarding the child-related, maternal, and environmental factors was collected. Psychiatric diagnoses were made according to the Chinese-Bilingual Structured Clinical Interview for DSM-IV Axis I Disorders. Independent factors associated with maternal affective disorders were determined by univariate and multivariate analyses. RESULTS: Of the 121 subjects, the point prevalence of affective disorders as a group was 29.8%. The point prevalence of major depressive disorders, adjustment disorders, anxiety disorders, and bipolar affective disorders was 14.9%, 10.7%, 3.3% and 0.8%, respectively. A higher level of disruptive and self-absorbed behaviours in the children (as assessed by the Developmental Behaviour Checklist), a higher level of affiliate stigma (as assessed by 22-item Affiliate Stigma Scale), and a history of psychiatric disorders were independently associated with current affective disorders. CONCLUSION: Psychiatric disorders, predominantly affective disorders, are common among Chinese mothers of preschool children with autism spectrum disorders. Identification of independent factors associated with maternal affective disorders can aid in the early detection of cases and planning of early intervention programmes to address both child and maternal psychological needs.


Autism Spectrum Disorder/epidemiology , Mood Disorders/epidemiology , Mothers/psychology , Mothers/statistics & numerical data , Adult , Autism Spectrum Disorder/psychology , Child, Preschool , China/epidemiology , Cross-Sectional Studies , Female , Humans , Male , Mood Disorders/psychology , Mother-Child Relations , Prevalence
7.
Oper Dent ; 41(3): E48-56, 2016.
Article En | MEDLINE | ID: mdl-26652018

OBJECTIVES: To evaluate the effect on both bond strength and microleakage of incorporation of a novel antibacterial nanoparticulate metal-titanate complex (nMT) into a dental adhesive system. MATERIALS AND METHODS: Eighty extracted human molars were prepared to determine whether incorporation of nMT into bonding agents can affect shear bond strength (SBS) and adhesive strength fatigue. SBS was measured with a universal testing machine, and the peak force at failure was recorded. An electromechanical fatigue machine was used for cyclic loading treatment of specimens. Differences in the SBS values among groups were identified using analysis of variance and Tukey post hoc analyses (α=0.05). Twenty standard Class V cavities were restored to examine microleakage when the primer/bonding resin was modified with 10 wt% nMT. Microleakage at the enamel and dentin margins was calculated as a percentage of the full length of the cavity. Results of the microleakage experiment were analyzed with paired and independent sample t-tests (α=0.05). RESULTS: The mean (± standard deviation) shear bond strength values of before fatigue and after fatigue ranged from 21.9 (2.5) MPa to 23.9 (3.8) MPa and from 17.1 (2.5) MPa to 17.7 (2.5) MPa respectively. No statistically significant differences in failure force were observed among groups (p=0.70). Microleakage under all conditions was significantly greater in the dentin margins than in the enamel margins (p<0.05). There was no evidence that microleakage differed between the experimental groups with modified primer and bonding resin. CONCLUSIONS: Incorporating nMT into a dental adhesive system will not compromise the resin composite's tooth bonding and sealing ability.


Anti-Bacterial Agents , Dental Bonding , Dentin-Bonding Agents , Resin Cements , Composite Resins , Dental Leakage , Dentin , Humans , Materials Testing , Metals , Shear Strength
8.
Dis Esophagus ; 29(4): 342-9, 2016 May.
Article En | MEDLINE | ID: mdl-25708811

Belching may result from transient lower esophageal sphincter relaxation; therefore, it has been proposed that belching may be a manifestation of gastroesophageal reflux disease (GERD). This study was conducted to investigate the frequency of belching during esophagogastroduodenoscopy (EGD) and its association with GERD. A retrospective review was performed on prospectively collected clinical and endoscopic data from 404 subjects who underwent EGD without sedation from December 2012 to May 2013 in a training hospital in Korea. All detectable belching events during endoscopy were counted. Frequency and severity of belching events were compared between the group with and without GERD using an ordinal logistic regression model. There were 145 GERD patients (26 erosive reflux disease and 119 nonerosive reflux disease [NERD]). In the multivariable analysis, GERD was significantly associated with a higher frequency of belching events (odds ratio = 6.59, P < 0.001). Central obesity, female, and younger age were also risk factors for frequent belching during EGD. Subgroup analyses were performed in subjects without erosive reflux disease (n = 378) and NERD (n = 293). NERD was also a predictive factor for frequent belching during EGD (odds ratio = 6.61, P < 0.001), and the frequency of belching was significantly correlated with GERD severity according to the Los Angeles classification (P < 0.05). Frequent belching during EGD was associated with GERD, including NERD. Future research should focus on its adjuvant role in the diagnosis of GERD/NERD and the necessity for applying differentiated endoscopy strategies for GERD patients, leading to less discomfort during EGD in patients at risk for intolerability.


Endoscopy, Digestive System , Eructation , Esophageal Sphincter, Lower , Gastroesophageal Reflux/physiopathology , Adult , Age Factors , Endoscopy, Digestive System/adverse effects , Endoscopy, Digestive System/methods , Eructation/diagnosis , Eructation/etiology , Eructation/physiopathology , Esophageal Sphincter, Lower/diagnostic imaging , Esophageal Sphincter, Lower/physiopathology , Female , Gastroesophageal Reflux/complications , Gastroesophageal Reflux/diagnosis , Humans , Male , Middle Aged , Outcome Assessment, Health Care , Risk Factors , Sex Factors , Statistics as Topic
9.
Childs Nerv Syst ; 31(12): 2375-8, 2015 Dec.
Article En | MEDLINE | ID: mdl-26156777

PURPOSE: We describe an extremely rare and previously unreported presentation of acute progressive paraparesis secondary to traumatic thoracic disc herniation in a child presenting to our institution. METHODS: A 12-year-old girl presented with progressive paraparesis 24 h after falling from standing height while playing at school. She was being lifted up by her friends and fell landing on her feet then rolled onto her back initially with no pain or neurological sequelae. Over the next few hours, she developed back pain followed by progressive paraparesis associated with urinary retention and sensory impairment. RESULTS: MR imaging demonstrated an unusual lateral and dorsally based lesion at T7/8 causing cord compression which was thought to represent an epidural haematoma. Urgent posterior decompressive surgery was performed but no evidence of haematoma was seen, a large well-circumscribed solid piece of soft tissue was found in the extradural space causing significant cord compression. This was sent for histological analysis and subsequently reported as showing cartilaginous disc material. Postoperative MR imaging at 2 weeks and 3 months demonstrates complete resection of this disc material with no significant kyphotic deformity on standing X-ray at 18 months. Complete neurological recovery occurred over the subsequent 3 months following emergent surgery, and at 18-month review, the patient remains asymptomatic and fully independent.


Intervertebral Disc Displacement/complications , Paraparesis/diagnosis , Paraparesis/etiology , Thoracic Vertebrae , Child , Female , Follow-Up Studies , Humans , Intervertebral Disc Displacement/surgery , Magnetic Resonance Imaging , Paraparesis/surgery , Thoracic Vertebrae/surgery
10.
Clin Neurol Neurosurg ; 135: 22-6, 2015 Aug.
Article En | MEDLINE | ID: mdl-26005741

BACKGROUND: Re-haemorrhage is a negative, prognostic predictor of outcome in aneurysmal subarachnoid haemorrhage (aSAH). The process of aSAH care has changed however, and most reports on re-haemorrhage are from a time when aneurysms were treated predominantly by open microneurosurgery. The current frequency and impact of re-haemorrhage on outcome in the 'post-ISAT' era is therefore unknown. The aim of this study was to review current outcome, risk factors and causes for inpatient re-haemorrhage in aSAH patients. METHOD: The departmental aSAH database was reviewed between Jan 2008 and March 2014 (N = 1008) to identify cases of re-haemorrhage. Re-haemorrhage was defined as inhospital deterioration in neurological status with CT confirmation of rebleeding. Binary logistic regression was used to (a) determine the impact of re-haemorrhage on outcome adjusted for age and injury severity and (b) to identify any independent predictors of its occurrence. RESULTS: Re-haemorrhage occurred in 55 (5.4%) of patients and most cases had occurred within 24h of ictus (32, 58.1%). Re-haemorrhage was an independent predictor of death (AOR 10.0, p < 0.0005, 95%CI 4.9, 20.2) and unfavourable outcome (AOR 5.8 p < 0.0005, 95%CI 2.4, 14.0). Only WFNS grade on admission was an independent predictor (AOR 1.7, p < 0.0005, 95%CI 1.4, 1.9) of re-haemorrhage. Of the patients who re-bled, in 20 there was no intention to treat due to severe brain injury and in the remainder, the majority occurred early (<24h) (19/35, 54%), or had complicated aneurysm morphology (10/35, 31%) which necessitated a delayed treatment strategy. CONCLUSIONS: Re-haemorrhage remains a poor prognostic predictor in aSAH and the grade of SAH is an independent risk factor. Earlier treatment of complex aneurysms could offer the most immediate improvements in its incidence.


Aneurysm, Ruptured/diagnostic imaging , Intracranial Aneurysm/diagnostic imaging , Subarachnoid Hemorrhage/diagnostic imaging , Adult , Aged , Aged, 80 and over , Aneurysm, Ruptured/mortality , Cerebral Angiography , Databases, Factual , Female , Humans , Intracranial Aneurysm/mortality , Logistic Models , Male , Middle Aged , Prognosis , Recurrence , Retrospective Studies , Risk Factors , Severity of Illness Index , Subarachnoid Hemorrhage/mortality
11.
Clin Neurol Neurosurg ; 115(8): 1356-61, 2013 Aug.
Article En | MEDLINE | ID: mdl-23332943

OBJECTIVE: Coiling of small (≤3 mm) cerebral aneurysms can be technically challenging and is associated with increased procedural-related morbidity and mortality. The authors report the clinical and radiological results following coiling of ruptured small cerebral aneurysms in a single-institution, and define the rates of intra-procedural rupture and thromboembolism. METHODS: A retrospective analysis was conducted on consecutive patients from 01/01/2008 to 31/12/2010 with subarachnoid haemorrhage (SAH) from ruptured cerebral aneurysms (≤3 mm) managed in a tertiary neurosurgical institution in the United Kingdom. RESULTS: Of the 108 patients identified, 72 patients (66.7%) underwent coil embolisation. A favourable outcome, defined as a Glasgow outcome score of 4-5, was achieved in 63 (87.5%) of these patients. Intra-procedural complications were observed in 11.1% (±7.3% 95% CI) of cases, wherein the rate of intra-procedural rupture was determined to be 8.3% (±6.4% 95% CI) and intra-procedural thromboembolism to be 2.8% (±3.8% 95% CI). CONCLUSION: Although coil embolisation of small ruptured cerebral aneurysms is technically feasible and an efficacious means of treatment, it is associated with an increased rate of intra-procedural complications. This should be taken into account when embarking upon treatment of patients with ruptured small cerebral aneurysms.


Aneurysm, Ruptured/complications , Aneurysm, Ruptured/therapy , Embolization, Therapeutic/adverse effects , Intracranial Aneurysm/complications , Intracranial Aneurysm/therapy , Adult , Aged , Aneurysm, Ruptured/mortality , Cerebral Angiography , Databases, Factual , Female , Glasgow Outcome Scale , Humans , Intracranial Aneurysm/mortality , Magnetic Resonance Imaging , Male , Middle Aged , Nervous System Diseases/etiology , Prospective Studies , Retrospective Studies , Risk , Tomography, X-Ray Computed , Treatment Outcome , Vasospasm, Intracranial/etiology , Vasospasm, Intracranial/therapy
12.
J Clin Neurosci ; 20(4): 514-9, 2013 Apr.
Article En | MEDLINE | ID: mdl-23317752

A retrospective analysis was conducted on consecutive patients with intracranial germ cell tumours diagnosed and treated from 1 January 1997 to 31 December 2007 to assess and determine demographic factors and treatment outcomes of children with these tumours treated in a major paediatric referral hospital in Australia. In this study, intracranial germ cell tumours represented 4.8% of paediatric brain tumours seen. Of the 21 patients identified, 15 (71.4%) were diagnosed with pure germinoma and six (28.6%) with non-germinomatous germ cell tumours (NGGCT) or mixed tumours. One patient received chemotherapy alone, two patients were treated with radiation alone and the remaining 18 received a combination of chemotherapy and radiotherapy. A total of 33 neurosurgical operations were performed with 15 biopsies via open, endoscopic or transphenoidal means; nine open resections; and nine procedures for hydrocephalus comprising seven third ventriculostomies and two ventriculoperitoneal shunts. For patients with pure germinomas, the 5-year disease-free rate (DFS) was 93.3%, and overall survival (OS) rate was 100% compared to NGGCT or mixed tumours (DFS 50%; OS 50%) (DFS p=0.019, OS p=0.004). The data presented show that pure germinomas carry a favourable prognosis. The data also support that treatment with induction chemotherapy followed by dose-attenuated radiotherapy is an effective alternative with results comparable to historical controls treated with craniospinal irradiation. Although chemoradiotherapy has become the mainstay of treatment in intracranial germ cell tumours, surgery remains integral to the management of this condition. Surgery remains important in establishing the histological diagnosis, as well as in the treatment of hydrocephalus. Furthermore, debulking procedures may be advocated in NGGCT as they are often resistant to chemotherapy.


Brain Neoplasms/therapy , Neoplasms, Germ Cell and Embryonal/therapy , Adolescent , Australia/epidemiology , Biomarkers, Tumor/blood , Brain Neoplasms/epidemiology , Brain Neoplasms/pathology , Chemoradiotherapy , Child , Combined Modality Therapy , Disease-Free Survival , Female , Humans , Male , Neoplasm Metastasis/pathology , Neoplasms, Germ Cell and Embryonal/epidemiology , Neoplasms, Germ Cell and Embryonal/pathology , Neurosurgical Procedures , Retrospective Studies , Treatment Outcome
13.
J Neurosurg Pediatr ; 6(4): 372-6, 2010 Oct.
Article En | MEDLINE | ID: mdl-20887112

Desmoid-type fibromatosis, aggressive fibromatosis, or desmoid tumor is an uncommon benign but locally aggressive fibroblastic lesion. Although intraabdominal desmoid-type fibromatoses are well described in association with adenomatous polyposis syndrome, their occurrence along the neuraxis is extremely rare. The authors report the case of a 14-year-old boy with metachronous intracranial and spinal desmoid-type fibromatoses with preceding medulloblastoma. He was ultimately diagnosed with adenomatous polyposis syndrome. This is the first reported case of spinal desmoid-type fibromatosis in association with adenomatous polyposis syndrome. The identification of an underlying genetic instability allows for screening to detect lesions and institute measures to avoid preventable mortality from nonneurological tumors.


Adenomatous Polyposis Coli/pathology , Cerebral Ventricle Neoplasms/pathology , Fibromatosis, Aggressive/pathology , Genes, APC , Neoplasms, Multiple Primary/pathology , Adenomatous Polyposis Coli/genetics , Adolescent , Cerebellar Neoplasms/genetics , Cerebellar Neoplasms/pathology , Cerebral Ventricle Neoplasms/genetics , Family Health , Fibromatosis, Aggressive/genetics , Humans , Magnetic Resonance Imaging , Male , Medulloblastoma/genetics , Medulloblastoma/pathology , Neoplasms, Multiple Primary/genetics , Pedigree
14.
J Mater Sci Mater Med ; 21(4): 1289-95, 2010 Apr.
Article En | MEDLINE | ID: mdl-19941042

Amorphous peroxotitantes (APT) are insoluble titanium-based particles that bind a variety of metal compounds with high affinity; these particles could be sequestered locally in a solid phase to deliver metal-based drugs. Previous studies have confirmed the 'biodelivery' of metals from metal-APT complexes to fibroblasts, but not monocytes. Our goal in the current study was to use monocytic cytokine secretion to assess delivery of gold or platinum-based compounds from APT to human THP1 monocytes. Cytokine secretion was not triggered by APT alone or metal-APT complexes. In monocytes activated by lipopolysaccharide (LPS), APT alone enhanced or suppressed IL1beta or IL6 secretion, yet TNFalpha secretion was unaffected. Complexes of APT and Au(III) or cis-platin altered LPS-activated IL6 or IL1beta secretion most, TNFalpha least. Our results suggest that the APT deliver metals to monocytes.


Drug Delivery Systems , Ions/pharmacokinetics , Metals/pharmacokinetics , Monocytes/metabolism , Titanium/pharmacokinetics , Biocompatible Materials/pharmacokinetics , Biocompatible Materials/pharmacology , Cells, Cultured , Cisplatin/administration & dosage , Cisplatin/pharmacokinetics , Drug Carriers/pharmacokinetics , Drug Carriers/pharmacology , Fibroblasts/drug effects , Fibroblasts/metabolism , Gold/pharmacokinetics , Gold/pharmacology , Humans , Interleukin-6/metabolism , Ions/administration & dosage , Lipopolysaccharides/pharmacology , Materials Testing , Metals/administration & dosage , Monocytes/drug effects , Oxides/pharmacokinetics , Oxides/pharmacology , Titanium/pharmacology , Tumor Necrosis Factor-alpha/metabolism
15.
J Oral Rehabil ; 36(3): 168-75, 2009 Mar.
Article En | MEDLINE | ID: mdl-19054290

This study examined the relationship between the subjective food intake of 30 food types and their objective bite force to identify the key food items within the 30 food types to achieve a greater depth of masticatory function in Korean adults. A sample of 308 (112 males and 196 females) adults over the age of 20 (average age, 48.6) was selected among patients who visited four dental hospitals in Seoul, Korea. The subjective masticatory ability was evaluated through an interview with food intake ability questionnaires consisting of 30 food types ranging from hard to soft using a five-step Likert scale. The objective maximal bite force was measured using pressure-sensitive films. The relationship between the food intake ability and bite force was analysed and stratified according to age, gender, number of post-canine teeth lost and several clinical oral health indicators. The key foods were selected using correlation and factor analysis. The subjective food intake ability between the 30 foods and key foods were tested by cluster and one-way anova analysis. The Pearson's correlation coefficient between food intake ability and bite force was 0.45 (P < 0.01). The five key food items selected were dried cuttlefish, raw carrot, dried peanut, cubed white radish kimchi and caramel. The correlation coefficient between the food intake ability and bite force of these items was 0.51 (P < 0.01). These results suggest that the subjective food intake ability using the 30 and five key foods can be used to evaluate the masticatory function in Korean adults.


Bite Force , Eating/physiology , Mastication/physiology , Adult , Aged , Aging/physiology , Cluster Analysis , Female , Food , Hardness , Humans , Male , Middle Aged , Tooth Loss/physiopathology , Young Adult
16.
J Oral Rehabil ; 36(2): 132-41, 2009 Feb.
Article En | MEDLINE | ID: mdl-18681936

The aim of this study was to evaluate the properties of four heat-pressed glass-ceramic materials after repeated heat-pressing. Two commercially available heat-pressed glass-ceramic systems [Optimal pressable glass-ceramics (OPC and 3G) and Empress pressable glass-ceramics (Empress and Empress2)] were selected. Disc samples (14 mm x 1.4 mm) of each tested material were heat-pressed and used as controls. Sprue and button parts of the pressed groups were retrieved and used for repeated heat-pressing to construct specimens of re-pressed group. All the heat-pressed casting procedures were performed according to the manufacturers' instructions. A biaxial flexural strength (BFS) test (ISO 6872) was performed to determine the strength of pressed and re-pressed glass-ceramic disc specimens (n = 10) at a crosshead speed of 0.5 mm min(-1). Ions eluted from etching procedure were collected and examined using inductively coupled plasma mass spectrometer. Surface characteristics were examined with electron probe microanalysis, X-ray diffraction and secondary electron imaging (SEI). The data were analysed statistically (ANOVA + Tukey's HSD post hoc test, P < 0.05). The BFS values obtained ranged from 123.5 +/- 18.5 to 365.9 +/- 35.5 MPa. The re-pressed Empress2 group had a statistically significant higher BFS mean than the pressed control group (P < 0.05). The SEI micrographs of the lithium disilicate-reinforced glass-ceramic material (Empress2) showed a densely packed, interlocking microstructure and an increase in size with preferred orientation of the lithium disilicate crystals after repeated heat-pressing. Repeated heat-pressing treatment produced a statistically significant increase in the flexural strength of Empress2 glass-ceramic material.


Ceramics , Compressive Strength , Dental Materials , Hot Temperature , Tensile Strength , Aluminum Silicates , Dental Porcelain , Electron Probe Microanalysis , Lithium Compounds , Mass Spectrometry/methods , Materials Testing/methods , Surface Properties , X-Ray Diffraction
17.
J Oral Rehabil ; 35(4): 268-75, 2008 Apr.
Article En | MEDLINE | ID: mdl-18321262

The aim of this study was to examine the bond strength between acrylic teeth after various surface treatments and processing with either a heat- or microwave-polymerized denture base material. Specimens were prepared and tested according to the methods described in American National Standard/American Dental Association Specification No.15 (Synthetic Polymer Teeth) using a special assembly. Three brands of acrylic teeth were used with the following treatments: control (no treatment), grinding and grinding plus sandblasting. Treatment groups were further divided into two denture base processing subgroups: heat-polymerized and microwave-polymerized methods. Denture base processing to the acrylic teeth was performed according to the manufacturer's recommendations. Bond strength test was performed using a universal testing machine with five specimens and each specimen is composed of six anterior teeth per experimental group. Data were analysed using a three-way anova and the Scheffe'F-test post hoc pair wise comparison at the 95% significance level. The mean bond strength values ranged from 33.1 +/- 4.1 to 51.6 +/- 2.5 MPa. The bond strength values of sandblasted surfaces were significantly higher than those of the ground surface and the control (P < 0.05). Combined (acrylic tooth and denture base resin) cohesive failures were disclosed in all tested samples. Acrylic tooth surface pre-processed surface treatment with grinding plus sandblasting and processed with a heat-polymerized denture base provided the greatest bond strength between acrylic tooth and denture base.


Dental Bonding , Denture Bases , Materials Testing , Tooth, Artificial , Dental Materials , Denture Repair/methods , Humans , Microscopy, Electron, Scanning , Polymethyl Methacrylate , Shear Strength , Surface Properties
18.
Surg Neurol ; 68(1): 43-9; discussion 49, 2007 Jul.
Article En | MEDLINE | ID: mdl-17586220

BACKGROUND: Nocardia species are aerobic Gram-positive bacteria that are ubiquitous in the environment. Infection usually occurs through inhalation or direct cutaneous inoculation of the organism. It has been reported that infection is more common in warm, dry climates. Cerebral nocardiosis is an uncommon clinical entity, representing only 2% of all cerebral abscesses. It is an illness associated with significant morbidity and mortality. CASE DESCRIPTIONS: We report 4 cases of nocardial brain abscesses presenting to TCH, Australia, within a 1-year period. All 4 cases occurred in men without any significant underlying immunocompromise. In 3 of the cases, the diagnosis was only established after craniotomy. All cases were given prolonged antimicrobial therapy. After more than 8 months of follow-up, there have been no deaths or treatment failures. There has been only one other case of nocardial brain abscess at TCH over the past 15 years. We review the current literature on cerebral nocardiosis. CONCLUSION: Nocardial brain abscesses are uncommonly encountered at our institution. This cluster of 4 cases over a 1-year period has therefore led us to postulate that the severe drought may be aiding in the transmission of the bacteria. The cases also emphasize the propensity of nocardial infections to mimic other conditions, particularly malignancy, which may lead to delays in appropriate surgical treatment and antimicrobial therapy. The diagnosis requires a high clinical index of suspicion, with early tissue and microbiological diagnosis. Prolonged antimicrobial therapy is required to prevent relapse of the infection.


Brain Abscess/microbiology , Nocardia Infections/complications , Aged , Anti-Infective Agents/administration & dosage , Anti-Infective Agents/therapeutic use , Brain Abscess/surgery , Cluster Analysis , Craniotomy , Diagnostic Techniques, Surgical , Drug Administration Schedule , Follow-Up Studies , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Nocardia Infections/diagnosis , Nocardia Infections/drug therapy , Nocardia Infections/microbiology , Nocardia asteroides/isolation & purification , Tomography, X-Ray Computed
19.
Vox Sang ; 93(1): 57-63, 2007 Jul.
Article En | MEDLINE | ID: mdl-17547566

BACKGROUND AND OBJECTIVES: Adequate blood supply is crucial to the health-care system. To maintain a stable donor pool, donation-promotion strategies should not only be targeted in recruitment but also focus on retaining donors to give blood regularly. A study using statistical modelling is conducted to understand the first 4-year donation patterns for drop-out and committed first-time blood donors and to build model for the donor-type identification based on their first 1.5-year donation patterns. SUBJECTS AND METHODS: First-time whole blood (n= 20 631) adult donors recruited in year 2000 and 2001 in Hong Kong were observed for more than 4 years. Cluster analysis was first applied to group donor type by their similarities in donation behaviour under the surveillance period. A decision tree model based on a shorter surveillance period (1.5 years) is then built to predict the donor type. RESULTS: Three donation patterns - one-time, drop-out, and committed donor behaviour - were identified in cluster analysis. Three variables - donation frequencies in the first-year and in the half-year period after first year, and the number of donation centre visits in the following half year after first year, were able to predict drop-out donors with potential to become committed and committed donors with relatively lower donation frequency. CONCLUSIONS: The present statistical modelling is able to identify those donors with potential to become committed donors and those committed donors who can donate more frequently. This information is useful for development of targeted donor retention strategies.


Blood Donors/supply & distribution , Models, Statistical , Adult , Asian People , Female , Forecasting/methods , Hong Kong , Humans , Male , Predictive Value of Tests
20.
J Clin Neurosci ; 14(8): 797-801, 2007 Aug.
Article En | MEDLINE | ID: mdl-17532220

Intracranial schwannoma not associated with the cranial nerves is rare. It is also an intriguing neoplasm since the Schwann cell is not native to the central nervous system. To date only four cases of intracranial schwannoma arising from the tentorium have been reported. We present a 49-year-old woman who harboured a schwannoma with a tentorial attachment in the right cerebellopontine angle and describe the relevant clinical, radiological and pathological findings. In addition, we briefly review the main hypotheses for the origin of this neoplasm and highlight its resemblance to meningioma and inclusion as a differential diagnosis.


Brain Stem Neoplasms/pathology , Cerebellar Neoplasms/pathology , Meningeal Neoplasms/diagnosis , Meningioma/diagnosis , Neurilemmoma/pathology , Brain Stem Neoplasms/surgery , Cerebellar Neoplasms/surgery , Female , Humans , Magnetic Resonance Imaging/methods , Middle Aged , Neurilemmoma/surgery , S100 Proteins/metabolism , Trigeminal Nerve Diseases/surgery , Trochlear Nerve Diseases
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