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1.
World J Microbiol Biotechnol ; 40(9): 276, 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39037634

RESUMO

Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne's disease, or paratuberculosis (PTB) in ruminants, besides having zoonotic potential. It possibly changes the gut microbiome, but no conclusive data are available yet. This study aimed at investigating the influence of MAP on the faecal microbiome of cattle naturally infected with PTB. In a follow up period of 10 months, PTB status was investigated in a herd of dairy cattle with history of clinical cases. Each animal was tested for MAP infection using serum and milk ELISA for MAP anti-bodies and IS900 real-time PCR and recombinase polymerase amplification assays for MAP DNA in the faeces and milk monthly for 4 successive months, then a last one after 6 months. The faecal samples were subjected to 16S rDNA metagenomic analysis using Oxford Nanopore Sequencing Technology. The microbial content was compared between animal groups based on MAP positivity rate and production status. All animals were MAP positive by one or more tests, but two animals were consistently negative for MAP DNA in the faeces. In all animals, the phyla firmicutes and bacteroidetes were highly enriched with a small contribution of proteobacteria, and increased abundance of the families Oscillospiraceae, Planococcaceae, and Streptococcacaceae was noted. Animals with high MAP positivity rate showed comparable faecal microbial content, although MAP faecal positivity had no significant effect (p > 0.05) on the microbiome. Generally, richness and evenness indices decreased with increasing positivity rate. A significantly different microbial content was found between dry cows and heifers (p < 0.05). Particularly, Oscillospiraceae and Rikenellaceae were enriched in heifers, while Planococcaceae and Streptococcaceae were overrepresented in dry cows. Furthermore, abundance of 72 genera was significantly different between these two groups (p < 0.05). Changes in faecal microbiome composition were notably associated with increasing MAP shedding in the faeces. The present findings suggest a combined influence of the production status and MAP on the cattle faecal microbiome. This possibly correlates with the fate of the infection, the concern in disease control, again remains for further investigations.


Assuntos
Doenças dos Bovinos , DNA Bacteriano , Fezes , Leite , Mycobacterium avium subsp. paratuberculosis , Paratuberculose , RNA Ribossômico 16S , Animais , Bovinos , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Mycobacterium avium subsp. paratuberculosis/genética , Fezes/microbiologia , Paratuberculose/microbiologia , RNA Ribossômico 16S/genética , Doenças dos Bovinos/microbiologia , Leite/microbiologia , DNA Bacteriano/genética , Microbioma Gastrointestinal , Feminino , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Metagenômica/métodos
2.
Ann R Coll Surg Engl ; 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37489547

RESUMO

INTRODUCTION: A novel referral pathway for exhibited breast symptom (EBS) referrals to manage increasing referrals of urgent suspected cancer (USC) was implemented in our trust. We report on the safety and effect on compliance with the 2-week-wait rule (2WW). METHODS: A single-centre longitudinal observational study included all patients referred to a UK breast unit during 13 May 2019 to 27 March 2020 (period 1) and 8 February 2021 to 31 January 2022 (period 2). USC referrals were assessed in a one-stop clinic (red flag clinic [RFC]); EBS referrals were assessed in a new clinic in which clinical evaluation was performed and imaging occurred subsequently (blue flag clinic [BFC]). Patients were followed up to determine the symptomatic interval cancer rate. RESULTS: There were 9,695 referrals; 1,655 referrals (17%) were assessed in the BFC after 63 exclusions. Some 95.9% of patients had a benign clinical examination (P1/P2), 80.1% had imaging (mammogram or ultrasound) and 4% had a tissue biopsy. In total, 16/1,655 (0.97%) BFC patients and 510/7,977 (8.2%) RFC patients were diagnosed with breast cancer (breast cancer detection rate). Some 1,631 patients (with 1,639 referrals) were discharged and followed up for a median of 17 months (interquartile range 12-32) with one subsequent cancer diagnosis (symptomatic interval cancer rate, 0.06%). Implementation of the BFC pathway increased 3-month average trust performance of USC referrals with 2WW standard from 8.5% to 98.7% (period 1) and from 30% to 66% (period 2). CONCLUSIONS: The BFC pathway for EBS patients is safe and implementation led to improvement against the 2WW target for USC referrals, ensuring resources are prioritised to patients with the highest likelihood of breast cancer.

3.
Interdiscip Perspect Infect Dis ; 2018: 4325752, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29568312

RESUMO

This study aimed to determine the prevalence of H. pylori infections among schoolchildren and investigate the associations between H. pylori seropositivity and existence of gastrointestinal symptoms. Methods. A prospective cross-sectional study was conducted during a period from January to December 2012 at Kassala state, east of Sudan. Schoolchildren from different primary schools were enrolled in the study. Sociodemographic characteristics and gastrointestinal symptoms were recorded from each child. A rapid immunochromatographic test was performed for the detection of H. pylori IgG antibodies. Data on patient demographic characteristics, clinical diagnosis, and findings of H. pylori infection were analyzed by simple descriptive statistics. Results. Among 431 schoolchildren, H. pylori seropositivity was found to be 21.8%. The majority of children (79; 84%) had BMI below the normal range. The most frequent symptoms associated with H. pylori infections were nausea (25.5%), followed by gastric pain (24.5%) and heart pain (20.2%). There were statistically significant differences in H. pylori seropositivity between boys and girls (p = 0.003). Conclusions. The prevalence of H. pylori infection among schoolchildren in Kassala city has been documented. Although the majority of the disease was associated with several gastrointestinal symptoms, the role of infection in the etiology of abdominal symptoms needs further investigations.

4.
Trop Anim Health Prod ; 45(2): 469-72, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22843216

RESUMO

Bovine tuberculosis (BTB) is a widespread zoonosis in developing countries but has received little attention in many sub-Saharan African countries including Sudan and particularly in some parts such as Darfur states. This study aimed to detect bovine tuberculosis among caseous materials of cattle slaughtered in abattoirs in South Darfur State, Sudan by using microscopic and PCR-based methods. The study was a cross-sectional abattoir-based study which examined a total of 6,680 bovine carcasses for caseous lesions in South Darfur State between 2007 and 2009. Collected specimens were examined for the presence of acid-fast bacilli (AFB) by using microscopic and culture techniques. Isolated mycobacteria were identified by selected conventional cultural and biochemical tests in comparison to a single tube multiplex PCR (m-PCR) assay which detect Mycobacterium bovis-specific 168-bp amplicons. Of the total 6,680 slaughtered cattle examined in South Darfur, 400 (6 %) showed caseations restricted to lymph nodes (86.8 %) or generalized (13.2 %). Bovine tuberculosis was diagnosed in 12 (0.18 %), bovine farcy in 59 (0.88 %), unidentified mycobacteria in 6 (0.09 %), and missed or contaminated cultures in 7 (0.1 %). Out of 18 cultures with nonbranching acid-fast rods, 12 amplified unique 168-bp sequence specific for M. bovis and subsequently confirmed as M. bovis. With the exception of the reference M. tuberculosis strains, none of the remaining AFB amplified the 337-bp amplicon specific for M. tuberculosis. It could be concluded that bovine tuberculosis is prevalent among cattle in South Darfur representing 4.5 % from all slaughtered cattle with caseous lesions. The study sustains microscopy as a useful and accessible technique for detecting AFB. m-PCR assay proved to be valuable for confirmation of BTB and its differentiation from other related mycobacteriosis, notably bovine farcy.


Assuntos
Doenças dos Bovinos/diagnóstico , Microscopia/métodos , Reação em Cadeia da Polimerase Multiplex/métodos , Infecções por Mycobacterium não Tuberculosas/veterinária , Mycobacterium bovis/isolamento & purificação , Tuberculose Bovina/diagnóstico , Matadouros , Animais , Autopsia/veterinária , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Contagem de Colônia Microbiana/métodos , Contagem de Colônia Microbiana/veterinária , Estudos Transversais , Pulmão/microbiologia , Linfonodos/microbiologia , Microscopia/veterinária , Reação em Cadeia da Polimerase Multiplex/veterinária , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Mycobacterium bovis/classificação , Prevalência , Sudão/epidemiologia , Tuberculose Bovina/epidemiologia , Tuberculose Bovina/microbiologia
5.
Stand Genomic Sci ; 9(1): 1-13, 2013 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-24501641

RESUMO

Staphylococcus aureus subsp. anaerobius is responsible for Morel's disease in animals and a cause of abscess in humans. It is characterized by a microaerophilic growth, contrary to the other strains of S. aureus. The 2,604,446-bp genome (32.7% GC content) of S. anaerobius ST1464 comprises one chromosome and no plasmids. The chromosome contains 2,660 open reading frames (ORFs), 49 tRNAs and three complete rRNAs, forming one complete operon. The size of ORFs ranges between 100 to 4,600 bp except for two ORFs of 6,417 and 7,173 bp encoding segregation ATPase and non-ribosomal peptide synthase, respectively. The chromosome harbors Staphylococcus phage 2638A genome and incomplete Staphylococcus phage genome PT1028, but no detectable CRISPRS. The antibiotic resistance gene for tetracycline was found although Staphylococcus aureus subsp. anaerobius is susceptible to tetracycline in-vitro. Intact oxygen detoxification genes encode superoxide dismutase and cytochrome quinol oxidase whereas the catalase gene is impaired by a stop codon. Based on the genome, in-silico multilocus sequence typing indicates that S. aureus subsp. anaerobius emerged as a clone separated from all other S. aureus strains, illustrating host-adaptation linked to missing functions. Availability of S. aureus subsp. anaerobius genome could prompt the development of post-genomic tools for its rapid discrimination from S. aureus.

6.
J Infect Dev Ctries ; 4(4): 235-8, 2010 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-20440061

RESUMO

BACKGROUND: The aim of the present study was to examine the phenotypic and genotypic relatedness of 17 Staphylococcus aureus subsp. anaerobius isolates recovered from sheep abscesses in Khartoum state, Sudan, during the period 2007-2008. METHODOLOGY: This sample was characterised using antibiogram typing, biochemical typing with the commercial PhenePlate system (PhP-CS) and multilocus sequence typing (MLST). RESULTS: Low levels of resistance were noted to the 11 antimicrobial agents tested. All the isolates corresponded to a single PhP type, and to a single, novel, multilocus sequence type, designated ST1464. CONCLUSION: These results demonstrate that the vast majority of cases of sheep abscess disease in Khartoum state are caused by a single novel clone of S. aureus subsp. anaerobius.


Assuntos
Abscesso/veterinária , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/classificação , Abscesso/epidemiologia , Abscesso/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Análise por Conglomerados , Impressões Digitais de DNA , Genótipo , Testes de Sensibilidade Microbiana , Análise de Sequência de DNA , Ovinos , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/fisiologia , Sudão/epidemiologia
7.
Saudi J Gastroenterol ; 16(1): 35-7, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20065572

RESUMO

BACKGROUND/AIM: Dyspepsia is a common gastrointestinal disorder and is the most common indication for upper gastrointestinal endoscopy (UGIE). In recent years, it has been observed in several centers that there is a change in the causes of dyspepsia as revealed by UGIE. Our main objectives were: (1) To study the pattern of upper gastrointestinal pathology in patients with dyspepsia undergoing upper endoscopy; (2) Compare that with the pattern seen 10-15 years earlier in different areas of KSA. MATERIALS AND METHODS: Retrospective study of all UGI endoscopies performed at Aseer Central Hospital, Abha, Southern Saudi Arabia during the years 2005-2007 on patients above 13 years of age. Patients who underwent UGIE for reasons other than dyspepsia were excluded. The analysis was performed using the SPSS 14 statistical package. RESULTS: A total of 1,607 patients underwent UGI endoscopy during the three-year study period (age range, 15-100). There were 907 males (56.4%) and 700 female (43.6%). Normal findings were reported on 215 patients (14%) and the majority had gastritis (676 = 42%), of whom 344 had gastritis with ulcer disease. Moreover, 242 patients (15%) had gastro-esophageal reflux (GERD), with or without esophagitis or hiatus hernia. Also, a total of 243 patients had duodenal ulcer (DU) (15%) while only 12 had gastric ulcer (0.7%). DISCUSSION AND CONCLUSION: There is clear change in the frequency of UGIE lesions detected recently compared to a decade ago with an increasing prevalence of reflux esophagitis and hiatus hernia. This could be attributed to changes in lifestyle and dietary habits such as more consumption of fat and fast food, increased prevalence of obesity, and smoking. These problems should be addressed in order to minimize the serious complications of esophageal diseases.


Assuntos
Dispepsia/etiologia , Dispepsia/patologia , Refluxo Gastroesofágico/complicações , Hérnia Hiatal/complicações , Adolescente , Adulto , Idoso , Endoscopia Gastrointestinal , Feminino , Refluxo Gastroesofágico/patologia , Hérnia Hiatal/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Arábia Saudita
8.
Saudi Med J ; 29(4): 530-2, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18382793

RESUMO

OBJECTIVE: To compare the usefulness of 4 commonly used tests in the diagnosis of Helicobacter pylori H. pylori infection in Saudi patients with dyspepsia. METHODS: Patients presenting with dyspepsia at the gastroenterology clinic of Aseer Central Hospital, Abha, Kingdom of Saudi Arabia between October 2005 to May 2006, who consented to participate in the study were enrolled. Patients who received anti-Helicobacter treatment or proton pump inhibitors within 30 days, or in whom endoscopy revealed cancer or gastro-esophageal reflux, were excluded from the study. Stool sample for H. pylori stool antigen HpSA were tested using the enzyme immunoassay technique 2-7 days before endoscopy. At endoscopy, gastric antrum mucosal biopsies were taken for campylobacter-like organism CLO test, histology and culture. RESULTS: There were 72 males and 43 females, age range from 18-75 years, mean age 40.09+/-15.68. Seventy-nine patients out of the 115 68.7% samples were positive for H. pylori, by culture. Culture and histology agreed in 112 cases 97.4% and disagreed in 3 cases 2.6%. The sensitivities and specificities % of histology were 97.5 and 97.2, of HpSAg were 91.9 and 98.6, and of CLO were 79.7 and 97.2 tests against culture. CONCLUSION: Culture, histology, and H. pylori stool antigen tests all have comparable results, and there is no need to use all 3 at the same time, for the diagnosis of H. pylori infection. The CLO test is less sensitive, and of low negative predictive value.


Assuntos
Infecções por Helicobacter/diagnóstico , Helicobacter pylori/isolamento & purificação , Adolescente , Adulto , Idoso , Antígenos de Bactérias/análise , Técnicas Bacteriológicas , Fezes/microbiologia , Feminino , Infecções por Helicobacter/patologia , Helicobacter pylori/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
9.
SADJ ; 61(7): 304-10, 312, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17133792
10.
SADJ ; 61(8): 352, 354, 356 passim, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17165249

RESUMO

Night Guard Vital Bleaching (NGVB) or dentist-monitored bleaching technique is probably the most widely used bleaching technique because of its relative ease of use, low cost, safety and high success rate. There are many non-vital bleaching techniques available, all of which have one thing in common, usually a successful result in the procedure returning the discoloured tooth to its original colour and beyond that when required. This article will give an overview of various home bleaching techniques: materials and regimens used, bleaching procedure and treatment of side-effects. In addition, it will review various in-surgery and at home techniques used for bleaching non-vital teeth.


Assuntos
Clareamento Dental/métodos , Peróxido de Carbamida , Combinação de Medicamentos , Humanos , Oxidantes/administração & dosagem , Satisfação do Paciente , Peróxidos/administração & dosagem , Autocuidado/métodos , Clareamento Dental/instrumentação , Ureia/administração & dosagem , Ureia/análogos & derivados
11.
Br Dent J ; 200(11): 631-4; discussion 619, 2006 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-16767142

RESUMO

OBJECTIVE: To measure the surface and pulp chamber temperature increases in vitro on upper and lower anterior teeth during a tooth whitening procedure using a diode laser. METHOD: A thermocouple was used to measure the temperature increase on the surface of an extracted upper central incisor tooth. Pulp chamber temperature readings were made on upper and lower central incisors, lateral incisors and canines. A diode laser recommended for tooth bleaching was tested at three different power settings (1W, 2W, 3W). Temperature measurements were made with and without the bleaching agent present on the labial tooth surface. RESULTS: The increase in surface temperature readings ranged from 37 degrees C (1W) to 86.3 degrees C (3W) with no bleaching gel present. Pulp chamber temperature increases ranged from 4.3 degrees C (1W) to 16 degrees C (3W). The presence of the bleaching gel reduced temperature increases seen at the tooth surface and within the pulp. CONCLUSIONS: The increase in the pulp chamber temperature with the laser used at 1-2W was below the critical temperature increase of 5.5 degrees C thought to produce irreversible pulpal damage. However, a power setting of 3W produced a pulp chamber temperature increase above this threshold (16 degrees C) and caution is advised when using this setting.


Assuntos
Temperatura Corporal , Polpa Dentária , Lasers , Clareamento Dental , Coroa do Dente , Esmalte Dentário , Dentina , Géis , Humanos , Incisivo , Oxidantes/química , Clareamento Dental/instrumentação
12.
Dent Update ; 32(8): 463-4, 466-8, 471, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16262034

RESUMO

The causes of tooth discoloration are varied and complex but are usually classified as being either intrinsic, extrinsic or internalized in nature. Dietary chromogens and other external elements deposit on the tooth surface or within the pellicle layer either directly or indirectly to form extrinsic discoloration. Stains within the dentine or intrinsic discoloration often results from systemic or pulpal origin, while internalized stains are the result of extrinsic stains entering the dentine via tooth defects such as cracks on the tooth surface.


Assuntos
Descoloração de Dente/etiologia , Fatores Etários , Amelogênese Imperfeita/complicações , Antibacterianos/efeitos adversos , Dentinogênese Imperfeita/complicações , Fluorose Dentária/complicações , Humanos , Tetraciclina/efeitos adversos , Desmineralização do Dente/complicações , Descoloração de Dente/classificação
13.
Br Dent J ; 199(1): 37-40; discussion 32, 2005 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-16003425

RESUMO

OBJECTIVE: To measure the surface and intra-pulpal temperature increases in vitro on upper and lower anterior teeth during tooth whitening procedures. METHOD: A thermocouple was used to measure the temperature increase on the surface of an extracted upper central incisor tooth. Intra-pulpal temperature readings were made on upper and lower central incisors, lateral incisors and canines. Four lamps recommended for tooth bleaching were tested; a plasma arc lamp, a xenon-halogen lamp, a standard halogen lamp and a diode laser lamp. Temperature measurements were made with and without the bleaching agent present on the labial tooth surface. RESULTS: The increase in surface temperature readings ranged from 0.44 degrees C (luma arch) to 86.3 degrees C (laser) with no bleaching gel present. Intra-pulpal temperature increases ranged from 0.30 degrees C to 15.96 degrees C. The presence of the bleaching gel reduced temperature increases seen at the tooth surface and within the pulp. CONCLUSIONS: The increase in the intrapulpal temperature with most bleaching lamps was below the critical threshold of a 5.50 degrees C increase thought to produce irreversible pulpal damage. The only lamp that produced an intrapulpal temperature increase above this threshold was the laser-based lamp and caution is advised when using this equipment.


Assuntos
Temperatura Corporal/fisiologia , Esmalte Dentário/fisiologia , Polpa Dentária/fisiologia , Clareamento Dental/métodos , Dente Canino/fisiologia , Géis , Humanos , Incisivo/fisiologia , Iluminação/instrumentação , Oxidantes/administração & dosagem , Oxidantes/uso terapêutico , Termômetros , Fatores de Tempo , Clareamento Dental/instrumentação
14.
Dent Update ; 32(2): 101-4, 107-8, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15819154

RESUMO

The use of in-surgery bleaching techniques has increased recently within the profession following the introduction of various new systems. Many dentists and patients alike prefer the in-surgery procedures to lighten teeth as it takes the responsibility for the procedure firmly away from the patient to the dentist; a situation with which both sides may be more comfortable. This article will review various in-surgery or power bleaching procedures. In addition, it will detail the procedure involved and how and when to combine bleaching techniques.


Assuntos
Clareamento Dental/métodos , Queimaduras Químicas/etiologia , Desidratação/induzido quimicamente , Equipamentos Odontológicos , Humanos , Peróxido de Hidrogênio/efeitos adversos , Luz , Oxidantes/efeitos adversos , Seleção de Pacientes , Ultrassom
15.
Dent Update ; 32(1): 39-40, 42-4, 46, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15739663

RESUMO

Night Guard Vital Bleaching (NGVB) or dentist-monitored bleaching technique is probably the most widely used bleaching technique because of its relative ease of use, low cost, safety and high success rate. There are many non-vital bleaching techniques available, all of which have one thing in common, usually a successful result in the procedure returning the discoloured tooth to its original colour and beyond that when required. This article will give an overview of various home bleaching techniques: materials and regimens used, bleaching procedure and treatment of side-effects. In addition, it will review various in-surgery and at home techniques used for bleaching non-vital teeth.


Assuntos
Clareamento Dental/métodos , Administração Tópica , Humanos , Oxidantes/administração & dosagem , Oxidantes/efeitos adversos , Oxidantes/uso terapêutico , Autocuidado , Clareamento Dental/efeitos adversos , Clareamento Dental/instrumentação , Dente não Vital/terapia
16.
J Dent ; 33(1): 33-40, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15652166

RESUMO

OBJECTIVES: The aim of the present study was to quantify the penetration of 35% hydrogen peroxide into enamel and dentine and to relate this to the resultant shade change of the tooth. METHOD: The crowns of 24 caries and developmental defect free human maxillary incisors were stained internally with a standardised tea solution. Twelve specimens were power bleached with light activated 35% hydrogen peroxide and 12 placed in water; both exposure times were 30min. Three different shade assessment methods (Vita shade guide [SG], shade vision system [SVS] and a chromometer) were employed prior to, after tea staining and after power bleaching/water treatments. Twelve specimens each from the bleach group and the water control water group were sectioned mesio-distally. An additional 12 specimens from the bleach and the control group were sectioned labio-palatally. The stain area for each specimen was measured using image analysis software. RESULTS: With tea staining, the mean changes in Vita shade guide units (SGU) ranged from 3.66 to 8.33. With the SVS system changes of 3.66-9 units were seen. Chromometer readings showed that following bleaching the L* values moved in the direction of black (3.8-6.7) and a* and b* values were in the red (0.3) and yellow (1.5) direction, respectively. Samples bleached and sectioned mesio-distally showed stain coverage of 28.6-39.4%, while palatal sections showed stain coverage of 58-72%. Control samples, whether sectioned mesio-distally or labio-palatally, showed staining throughout the dentine (97-100% coverage). CONCLUSION: A 35% hydrogen peroxide in-office bleaching gel demonstrated bleaching into dentine of uniform depth.


Assuntos
Dentina/metabolismo , Peróxido de Hidrogênio/farmacocinética , Oxidantes/farmacocinética , Clareamento Dental , Descoloração de Dente/terapia , Análise de Variância , Esmalte Dentário/metabolismo , Permeabilidade do Esmalte Dentário , Permeabilidade da Dentina , Humanos , Peróxido de Hidrogênio/uso terapêutico , Incisivo , Oxidantes/uso terapêutico , Distribuição Aleatória , Chá/efeitos adversos , Descoloração de Dente/induzido quimicamente
17.
J Dent ; 32(7): 581-90, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15386865

RESUMO

OBJECTIVE: The aim of this study was to investigate safety concerns with bleaching procedures by studying the effects of a high concentration hydrogen peroxide (HP) in-surgery bleaching product on enamel and dentine. METHOD: Flat enamel and dentine samples embedded in epoxy resin were prepared from human third molar teeth. Erosion of enamel: groups of enamel samples were treated with 35% HP then citric acid (CA) or brushing with toothpaste or CA alone and water alone. Enamel Loss was measured using a profilometer. Abrasion/erosion of dentine: groups of dentine specimens were treated as follows: Group 1--brushed with water for 30 min. Group 2--brushed with 35% HP for 30 min. Group 3--power bleached for 30 min and then Group 4--brushed with toothpaste for 1 minute. Group 5--water soaked for 30 min followed by brushing with toothpaste for 1 min. Group 6--orange juice soaked for 30 min followed by brushing with toothpaste for 1 min. Treatment effects were measured using a profilometer. Hardness tests: enamel and dentine specimens were hardness tested using a Wallace indenter prior to and post bleaching. Scanning Electron Microscopy: enamel and dentine specimens were taped and the exposed tissue treated with 35% HP and then studied under scanning electronmicroscopy (SEM). RESULTS: Enamel erosion: bleaching enamel samples had no measurable effect on enamel. Pre-bleaching had no significant effect on subsequent CA erosion or brushing. Abrasion/erosion of dentine: no significant differences were found between treatments 1-5 with little change from baseline detected. Orange juice (Group 6) produced considerable and significantly more erosion than other treatments. Hardness tests: there were no significant changes in hardness values for enamel and dentine. SEM: there was no evidence of any topographical changes to either enamel or dentine. CONCLUSION: Using one of the highest concentrations of HP for tooth bleaching procedures and maximum likely peroxide exposure, there was no evidence of deleterious effects on enamel or dentine. It must be assumed that studies which reported adverse effects on enamel and or dentine of bleaches reflect not the bleach itself but the pH of the formulation used.


Assuntos
Esmalte Dentário/efeitos dos fármacos , Dentina/efeitos dos fármacos , Peróxido de Hidrogênio/uso terapêutico , Oxidantes/uso terapêutico , Clareamento Dental/métodos , Bebidas/efeitos adversos , Quelantes/efeitos adversos , Ácido Cítrico/efeitos adversos , Citrus sinensis , Frutas , Dureza , Humanos , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Segurança , Estatísticas não Paramétricas , Abrasão Dentária/etiologia , Clareamento Dental/normas , Erosão Dentária/induzido quimicamente , Escovação Dentária , Cremes Dentais/uso terapêutico
18.
Eur J Prosthodont Restor Dent ; 12(1): 15-20, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15058177

RESUMO

There has been some disquiet over the use of mercury containing restorative materials. The most commonly used alternative is composite resin but this has the potential disadvantage associated with wear and marginal leakage, which in turn, has proven to result in secondary caries and sensitivity. To overcome the shortcomings of a directly placed composite restoration, the glass-ionomer/composite open sandwich technique was introduced followed by the subsequent introduction of compomer systems. The aims of this study were to evaluate the wear and clinical performance of a control group of amalgam restorations compared with that of a group of posterior composite resin restorations fillings and a group of compomer/composite open sandwich restorations placed by a single general dental practitioner. The duration of the study was 2 years. One hundred and thirty three (71.4%) patients were successfully recalled and the wear and clinical performance of each restoration after 6, 12 and 24 months was measured, indirectly. There was no statistically significant difference recorded between the groups at 6 months or 1 year (p > 0.05). However, at the end of the 2-year study, there was a significantly lower rate of wear recorded for the control amalgam restorations compared with other two groups (p = 0.033). There was no statistically significant difference in wear recorded between the two groups of tooth-coloured restorations (p > 0.05). With regards to clinical performance of the restorations, occlusal and proximal contacts in each group of restoration remained satisfactory throughout the study.


Assuntos
Desgaste de Restauração Dentária , Restauração Dentária Permanente/métodos , Acetona , Adolescente , Adulto , Compômeros , Resinas Compostas , Amálgama Dentário , Adesivos Dentinários , Humanos , Ácidos Polimetacrílicos , Estudos Prospectivos , Cimentos de Resina , Estatísticas não Paramétricas
19.
J Dent ; 32(4): 295-9, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15053912

RESUMO

AIM: This in vitro study examined the effect that various concentration of hydrogen peroxide (5-35%) had on tooth whitening. METHOD: Extracted third molars were sectioned and stained using a standardised tea solution to Vita shade C4. These stained specimens were then bleached with a series of gels containing 5, 10, 15 or 25% w/w hydrogen peroxide. Each specimen was bleached for a number of sessions with one session being defined as 3 x 10 min exposure. RESULTS: The number of applications of the various concentrations of bleaching gel varied from 12 applications for the 5% gel to one application for the 35% gel. Plotting the number of applications against hydrogen peroxide concentration showed an exponential response curve. CONCLUSIONS: The concentration of hydrogen peroxide in a proprietary bleaching gel had a marked effect on the number of applications required to produce an optimal shade outcome.


Assuntos
Peróxido de Hidrogênio/administração & dosagem , Oxidantes/administração & dosagem , Clareamento Dental , Algoritmos , Análise de Variância , Colorimetria , Relação Dose-Resposta a Droga , Eletrônica , Géis , Humanos , Processamento de Imagem Assistida por Computador , Dente Serotino/patologia , Chá/efeitos adversos , Fatores de Tempo , Descoloração de Dente/terapia , Resultado do Tratamento
20.
Dent Update ; 31(10): 608-10, 612-4, 616, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15656076

RESUMO

The use of a variety of bleaching techniques has attracted much interest from the profession, as they are non-invasive and relatively simple to carry out. Coupled with the uncertain legal situation within the European community, and especially within the UK, this series of articles hopes to give a broad overview of bleaching techniques, their efficacy and relative safety, as well as update the current legal situation. This article will give an overview of bleaching: history, chemistry and safety. In addition, it will summarize types of tooth discoloration, along with indications/contra-indications for bleaching. Future articles will address in detail both home and power bleaching techniques, as well as the various ways to bleach non-vital teeth.


Assuntos
Peróxido de Hidrogênio/uso terapêutico , Clareamento Dental/métodos , Descoloração de Dente/tratamento farmacológico , Contraindicações , Humanos , Propriedades de Superfície/efeitos dos fármacos , Clareamento Dental/efeitos adversos , Descoloração de Dente/etiologia , Reino Unido
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