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1.
BMC Med Educ ; 23(1): 767, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37833687

RESUMO

BACKGROUND: The Coronavirus Disease (COVID-19) outbreak has caused especially health workers to face mental and physical problems all over the world. The aim of this study is to evaluate burnout, stress perception and perceived social support levels of clinical (the fourth and fifth year) dental students during the COVID-19 pandemic. METHODS: The Sociodemographic Information Form (SIF), Maslach Burnout Inventory (MBI), Sense of Coherence-13 (SoC-13), Perceived Stress Scale-10 (PSS-10), and Multidimensional Scale of Perceived Social Support (MSPSS) were used for data. Questionnaires were answered directly or online by the participants. RESULTS: A total of 211 participants, 67.8% were female, 32.2% were male. Of these, 96.2% were aged 20-24 years, 84.4% were nuclear family, 11.8% were extended family, and 3.8% were blended family, and 91.5% were willingly for dentistry choice. Based on the results; the total burnout score indicated moderate burnout (41.99 ± 9.94), the SoC-13 scale indicated a strong sense of coherence (55.24 ± 7.21), the PSS-10 score (22.44 ± 3.44) indicated moderate perceived stress and the MSPSS score (65.92 ± 13.22) indicated high perceived social support. A positive correlation was found between perceived stress and burnout. Based on the personal accomplishment subscale; females, those living in extended family, and those who unwillingly choose dentistry among the clinical dental students had higher intense burnout (p < 0.05). CONCLUSIONS: The findings demonstrated that clinical dental students were affected by the emotional stress caused by the COVID-19 pandemic conditions. In the education of dentistry faculties, it would be appropriate to carry out comprehensive studies on adaptation to the changing living conditions with the COVID-19 pandemic and taking the necessary measures for the psychological distress caused by the difficulties experienced.


Assuntos
Esgotamento Profissional , COVID-19 , Humanos , Masculino , Feminino , Estudantes de Odontologia/psicologia , Pandemias , Estresse Psicológico/epidemiologia , COVID-19/epidemiologia , Esgotamento Psicológico/epidemiologia , Esgotamento Profissional/epidemiologia , Esgotamento Profissional/psicologia , Inquéritos e Questionários
2.
Ann Med ; 55(1): 860-868, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-36896488

RESUMO

BACKGROUND: The coronavirus disease-2019 (COVID-19) pandemic has caused healthcare professionals to face unequal acute workplace stress and burnout. This study aimed to analyze the potential impact of COVID-19 on the burnout and associated emotional stress conditions of Turkish dental technicians. METHODS: A 20-question demographic scale, Maslach Burnout Inventory (MBI), Sense of Coherence-13 (SoC-13), and Perceived Stress Scale-10 (PSS-10) were used to obtain data. A total of 152 participants answered these surveys directly and reported their stress burnout levels during the COVID-19 pandemic. RESULTS: Of all participants who agreed to participate in the survey, 39.5% were females and 60.5% were males. Regardless of demographic variables, the MBI-total (37.2 ± 11.71), SoC-13 total (53.81 ± 10.29), and PSS-10 total (21.25 ± 5.5) scores indicated moderate burnout, SoC, and perceived stress levels. According to sub-scores of the MBI; mean emotional exhaustion and depersonalization indicate low-level burnout, and mean personal accomplishment indicates moderate burnout. Long working hours increase burnout. No significant differences were observed according to demographic variables, except for work experience. A positive correlation was found between perceived stress and burnout. CONCLUSIONS: The findings showed that dental technicians working during the COVID-19 pandemic are influenced by emotional stress due to the outcomes of the pandemic. One reason for this situation might be the long working hours. Working arrangements, under-controlled disease risk factors, and lifestyle changes may improve stress levels.Key MessagesCOVID-19 outbreak exposed psychological returns to the general population, and especially to healthcare workers.Questionnaire method was applied to evaluate the burnout and stress levels among dental laboratory technicians during COVID-19 outbreak.Moderate levels of burnout and stress perception were detected. Long working time was one of the effective factors.


Assuntos
Esgotamento Profissional , COVID-19 , Pessoal de Laboratório , Masculino , Feminino , Humanos , Pandemias , COVID-19/epidemiologia , Esgotamento Profissional/epidemiologia , Esgotamento Profissional/psicologia , Esgotamento Psicológico/epidemiologia , Inquéritos e Questionários , Percepção
3.
BMC Oral Health ; 22(1): 524, 2022 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-36419112

RESUMO

BACKGROUND: The roughening of the inner surface of a fixed ceramic restoration is an important factor for the bonding process. The aim of this study is to investigate the effect of combined surface treatments (acid etching, air-abrasion and Er: YAG Laser) on surface roughness of CAD/CAM fabricated zirconia (ZrO2) and lithium-disilicate glass ceramics (LDS). METHODS: Sixty ZrO2 (Ceramill Zi) and LDS (IPS e.max CAD) specimens, (5 mm in width, 5 mm in length and 1.5 mm in height) were fabricated using CAD/CAM and sintered according to the manufacturer's instructions. All specimens subjected to three surface treatment combinations; etching with 4% hydrofluoric acide (HF), airborne-particle abrasion with 110-µm alumina (Al2O3) (AP) and Er:YAG laser (Er:YAG) (Group A-HF + AP; Group B-Er:YAG + AP, and Group C-Er:YAG + HF). Perthometer was used to measure the surface roughness of the specimens before and after the tretments. RESULTS: Group A presented the highest Ra (LDS 0.81 ± 0.27 and ZrO2 0.67 ± 0.21 after treatment) and Group C the lowest (LDS 0.45 ± 0.13 and ZrO2 0.26 ± 0.07, after treatment). Compared with before treatment, the Ra were significantly different only in Group A both ZrO2 and LDS after treatment (p < 0.05). Qualitative SEM images suggested the surface topography of the ZrO2 was smoother than the LDS. Less surface changes were observed in the Er:YAG combined procedures than HF + AP. CONCLUSIONS: HF + AP was significantly succesful in modifying the ceramic surface. Er:YAG did not sufficiently promote the surface topography, even if combined with any other treatments. Overall, surface tretments on ZrO2 not easier than LDS.

4.
J Med Life ; 14(5): 683-689, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35027971

RESUMO

This study aimed to assess Oral Health-Related Quality of Life (OHQoL) and satisfaction in patients who had complete denture treatment and were diagnosed with systemic diseases. Eighty edentulous patients using new complete dentures were separated into four groups according to their diseases [diabetes mellitus (DM)/osteoporosis (OP)/hypertension (HP)/healthy (control)]. The groups answered the Turkish version of the United Kingdom-Oral Health-Related Quality of Life (OHQoL-UK) and Visual Analog Scale (VAS) questionnaire four weeks after treatment. OHQoL-UK scores were slightly higher for females regardless of the type of disease. Compared with the control participants (57.95±5.33), the scores of the OHQoL-UK were not significantly different in OP and HP groups except for the DM group (58.7±5.37, 58.9±6.44, 45.3±5.19 respectively). DM was significantly associated with the increase of OHQoL values (p<0.05). Patients in all groups reported significantly higher "physical health" scores than other subdomains of OHQoL-UK, although positive correlations were determined among them. Presence of disease had no relationship to the VAS scores. This study shows that systemic diseases might not affect and predict patients' satisfaction with their complete dentures and OHQoL. DM is an independent risk factor for oral health. Satisfaction with the prosthesis might concern a patient's level of OHQoL.


Assuntos
Saúde Bucal , Qualidade de Vida , Prótese Total , Feminino , Humanos , Satisfação do Paciente , Inquéritos e Questionários
5.
J Prosthet Dent ; 118(4): 551-560, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28385440

RESUMO

STATEMENT OF PROBLEM: Several factors affect the prosthetic outcome of patients with mandibular defects. However, it is questionable whether fixed or removable implant-supported prostheses meet the expectations and satisfaction of the patients. The perspectives of these patients are important in managing the prosthetic treatment strategies. PURPOSE: The purpose of this prospective clinical study was to evaluate the satisfaction and oral health-related quality of life of patients with marginal mandibulectomies with implant-retained overdentures and fixed metal-acrylic resin prostheses. MATERIAL AND METHODS: Twenty-two participants with marginal mandibulectomies were included in the study. They completed an oral health impact profile questionnaire designed for patients with edentulism (OHIP-Edent) for the assessment of quality of life and visual analog scales (VASs) to validate their general satisfaction before treatment. Ten participants received 4 implant-retained fixed metal-acrylic resin prostheses, whereas 12 participants were treated with 2 implant-supported overdentures. Six months after delivery of their prostheses, the participants completed the OHIP-Edent questionnaire and VAS again. For the statistical analyses, Student t tests together with descriptive statistics (mean, standard deviation, frequency) were used in the 2 intergroup parameter comparisons that showed normal distribution. The Mann-Whitney U test and Kruskal-Wallis test were used for intergroup comparisons, and the Wilcoxon signed rank test was used for intragroup comparisons. RESULTS: Compared with pretreatment mean values, a statistically significant (P<.05) decrease in mean scores of all OHIP-Edent values and an increase in VAS scores were found in both groups. After patients were treated, their OHIP-Edent values in the group with an overdenture prosthesis were higher than those in the group with a fixed metal-acrylic resin prosthesis (P<.05). CONCLUSIONS: These results demonstrate that implant-retained overdentures and fixed metal-acrylic resin prostheses provide better function and, thus, oral health-related quality of life for patients with marginal mandibulectomies.


Assuntos
Resinas Acrílicas , Prótese Dentária Fixada por Implante , Revestimento de Dentadura , Osteotomia Mandibular/métodos , Metais , Qualidade de Vida , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
6.
J Oral Implantol ; 41(1): 30-5, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23270595

RESUMO

The purpose of this study was to clinically monitor the stability of dental implants in patients with and without a history of radiotherapy, using resonance frequency analysis over 1 year. The stability of patients with 80 implants was monitored with resonance frequency analysis (Osstell Mentor) over 1 year. Data were assessed with Mann-Whitney U test and correlation analysis. Irradiated maxillary implants showed statistically lower values than the mandibular implants at a significant level (P < .05).


Assuntos
Implantes Dentários , Retenção em Prótese Dentária , Neoplasias de Cabeça e Pescoço/radioterapia , Osseointegração/fisiologia , Adulto , Projeto do Implante Dentário-Pivô , Implantação Dentária Endóssea/métodos , Feminino , Seguimentos , Humanos , Masculino , Mandíbula/efeitos da radiação , Mandíbula/cirurgia , Maxila/efeitos da radiação , Maxila/cirurgia , Pessoa de Meia-Idade , Osseointegração/efeitos da radiação , Análise de Sobrevida , Vibração
7.
Gerodontology ; 31(1): 19-24, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22672143

RESUMO

OBJECTIVES: There is a lack of data regarding whether edentulous subjects should remove dentures during spirometric measurements or not. The purpose of this study is to determine influences of complete dentures on spirometric parameters in edentulous subjects. MATERIALS AND METHODS: A total of 46 complete denture wearers were included in this study. Respiratory functions of the subjects were evaluated by spirometric tests that were performed in four different oral conditions: without dentures (WOD), with dentures, lower denture only and upper denture only. Forced vital capacity (FVC), peak expiratory flow, forced expiratory volume in 1 s and forced expiratory flow between 25% and 75% were evaluated. The data were analyzed with Friedman, Wilcoxon and paired-samples t tests (α = 0.05). RESULTS: Significant differences were found between spirometric parameters in different oral conditions (p < 0.05). In all spirometric parameters, the most important significant differences were found between conditions WOD, FVC and with lower dentures (FVC), and WOD (forced expiratory volume in 1 s) and with upper dentures (forced expiratory volume in 1 s) (p < 0.001). CONCLUSION: It was observed that complete dentures may unfavourably affect spirometric values of edentulous subjects. However, current findings need to be confirmed with advanced respiratory function tests.


Assuntos
Prótese Total , Respiração , Espirometria/métodos , Índice de Massa Corporal , Prótese Total Inferior , Prótese Total Superior , Feminino , Volume Expiratório Forçado/fisiologia , Humanos , Masculino , Fluxo Máximo Médio Expiratório/fisiologia , Pessoa de Meia-Idade , Boca Edêntula/fisiopatologia , Pico do Fluxo Expiratório/fisiologia , Espirometria/instrumentação , Capacidade Vital/fisiologia
8.
Health Qual Life Outcomes ; 11: 11, 2013 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-23351906

RESUMO

BACKGROUND: Facial prostheses are intended to provide a non-operative rehabilitation for patients with acquired facial defects. By improving aesthetics and quality of life (QOL), this treatment involves reintegration of the patient into family and social life. The aim of this study was to evaluate the perception of QOL in adult patients with facial prostheses and to compare this perception with that of a control group. METHODS: The study participants consisted of 72 patients, who were divided into three equal-sized groups according to the type of prosthesis (OP- orbital prosthesis, AP- auricular prosthesis, NP - nasal prosthesis) and 24 healthy control participants without any congenital or acquired deformity of face or body. Clinical and socio-demographic data were gathered from each person's medical chart. Participants completed the Turkish version of the World Health Organization Quality of Life Instrument, Short Form (WHOQOL-BREF). Descriptive statistics, independent sample t-tests, Pearson's chi-square test, ANOVA, ANCOVA, and Pearson correlation were used to analyse the data. RESULTS: Compared with the control participants, patients with NP scored lower on the all domains of QOL and all three patient groups had lower scores on overall QOL and its domains of physical and environmental health. Patients with OP reported significantly lower physical health scores than those with AP, while patients with NP reported significantly lower overall QOL and psychological health scores than those with AP. Female patients had lower environmental domain scores than did male patients. The patient's age and income correlated with social relationships QOL, while the patient's income and the age of facial prosthesis were correlated with environmental QOL. CONCLUSION: Patients with facial prostheses had lower scores in overall QOL, physical and environmental health domains than the control participants. Socio-demographic and clinical characteristics such as age, gender, income, localization of the defect, and age of facial prosthesis were associated with patients' QOL. These findings may provide valuable information about the specific health needs of these patients that may affect their well-being. Further studies are needed to confirm these results. Use of the WHOQOL-BREF may provide valuable information for determining patients' needs and priorities as well as for planning and developing comprehensive prosthetic rehabilitation programs.


Assuntos
Face , Próteses e Implantes/psicologia , Qualidade de Vida/psicologia , Estudos de Casos e Controles , Estudos Transversais , Orelha/anormalidades , Face/anormalidades , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nariz/anormalidades , Implantes Orbitários/psicologia , Inquéritos e Questionários , Turquia
9.
Cleft Palate Craniofac J ; 50(1): 109-12, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22034988

RESUMO

Objectives : Cleft palate is a common congenital maxillofacial defect. We wish to present the fabrication of a modified feeding plate that will adapt to the changing palatal and velopharyngeal morphology during function. Case Report : A neonate with unilateral cleft lip and palate was referred to our clinic for the fabrication of a feeding plate. Intraoral examination revealed a cleft involving the uvula and the soft palate, with an alveolar defect on the left side. An impression was taken and a dental cast was obtained. A 1-mm Bioplast clear soft plate was pressed on the model. After trimming the edges of the plate, several retentive holes were made for its attachment to the hard plate. With the Bioplast soft plate replaced on the cast, plaster was used to cover parts of the soft plate that were not to come in contact with the hard plate. Biocryl resin was put on the retentive holes and 2-mm Biocryl C Rosa-transparent plate was pressed. The edges of the plate were cut, trimmed, and polished. Conclusion : This modified feeding plate effectively obstructed the soft palate defect. The adaptation of the flexible bulb of the appliance with the soft palate was excellent. Evaluation with nasoendoscopy revealed the synchronized movement of the bulb of the appliance with the soft palate during swallowing. Soft extension of the feeding plate eliminated the risk of irritation, and the baby accepted the appliance easily.


Assuntos
Fenda Labial , Fissura Palatina , Humanos , Recém-Nascido , Palato Mole
10.
J Craniofac Surg ; 21(3): 751-8, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20485041

RESUMO

Extraoral implants for the retention of facial prosthesis have been used for better support, stability, and retention. Other than the clinical experiences, treatment outcomes of these prostheses should be evaluated for predicting the long-term success. The aim of this study was to evaluate the survival rates and soft tissue responses of extraoral implants. In total, 52 patients were examined, including 16 with auricular defects, 16 with orbital defects, 13 with nasal defects, and 7 with midfacial defects. Data on implant length and location, radiation-treatment history, systemic diseases, and alcohol and cigarette use were collected and assessed, and data on the health of periimplant soft tissue were recorded for all of the defects. Statistical analyses were performed with t and chi2 tests and correlation and regression analyses for the determination of the survival rate. According to results, the defect area has a significant effect on success rate. The overall success rate was found highest in the auricular area and least in the midfacial area. The presence of diabetes, alcohol use, and age were found as significant factors for implant loss, whereas smoking and radiotherapy were found as insignificant.


Assuntos
Próteses e Implantes , Implantação de Prótese/instrumentação , Adolescente , Adulto , Idoso , Distribuição de Qui-Quadrado , Criança , Orelha Externa , Face , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nariz , Implantes Orbitários , Falha de Prótese , Análise de Regressão , Taxa de Sobrevida , Resultado do Tratamento
11.
Dent Mater J ; 29(2): 147-53, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20379024

RESUMO

Candida albicans, known for its adhesion on prosthetic materials and oral tissues, is the most frequently encountered fungal infection in dentistry. The aim of this study was to evaluate the effects of four different surface treatment methods and immersion in artificial saliva on the surface roughness of and candida adhesion on dental porcelains. The four surface treatment methods were namely: natural glaze, overglaze, dual ion exchange, and polishing. Surface roughness of porcelain was evaluated using a surface profilometer and by SEM. Candida adhesion was examined by culturing two Candida strains on porcelain specimens followed by a colorimetric method using XTT/Coenzyme Q0. It became evident that Candida adhesion was found more in the specimens treated with natural glaze and polishing. Further, by the visual inspection of SEM images and comparison of surface roughness, polished and natural-glazed specimens showed rougher surface characteristics than overglazed and dual-ion-exchanged specimens.


Assuntos
Silicatos de Alumínio/química , Candida albicans/fisiologia , Porcelana Dentária/química , Compostos de Potássio/química , Adesão Celular/fisiologia , Colorimetria , Técnica de Fundição Odontológica , Polimento Dentário , Temperatura Alta , Humanos , Indicadores e Reagentes , Troca Iônica , Cloreto de Lítio/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Saliva Artificial/química , Cloreto de Sódio/química , Propriedades de Superfície , Sais de Tetrazólio , Ubiquinona
12.
Quintessence Int ; 40(7): e41-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19626223

RESUMO

OBJECTIVE: To investigate the effects of porcelain treatment techniques on the color change of feldspathic porcelain before and after exposure to distilled water, coffee, red wine, and cola and examine the surface texture of the porcelain with field-emission SEM. MATERIALS AND METHODS: Test specimens were prepared in the form of discs 15 mm in diameter by 2-mm thick and divided into four groups: Naturalglaze, dual-ion exchange, overglaze and polishing. The specimens were prepared according to their group and stored in red wine, coffee, and cola. After removal, the specimens were dipped in distilled water. Color measurements were made with a spectrophotometer, and color differences were determined using the CIE-LAB system. Statistical analysis was made with SPSS 13.5. RESULTS: Immersion time and types of surface treatment were significant factors for color stability (P < .01).


Assuntos
Bebidas , Porcelana Dentária , Corantes de Alimentos , Café , Cola , Cor , Colorimetria , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Vinho
13.
J Craniofac Surg ; 20(4): 1169-72, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19553846

RESUMO

This article describes the use of computed tomography and rapid prototyping method to produce a wax pattern of a missing ear. Computed tomographic scans were obtained from the patient, and a three-dimensional digital image was produced using a computer-aided design software. Then, the image of the present ear was extracted, and its mirror image was obtained with the software. The pattern of the inverted three-dimensional cast was produced using a rapid prototyping machine. The cast was duplicated in wax of identical dimensions and shape of the opposing ear, and the auricular prosthesis was fabricated with traditional methods.


Assuntos
Desenho Assistido por Computador , Orelha Externa/anormalidades , Desenho de Prótese/métodos , Tomografia Computadorizada por Raios X , Orelha Externa/diagnóstico por imagem , Humanos , Masculino , Modelos Anatômicos , Ajuste de Prótese , Adulto Jovem
14.
Cleft Palate Craniofac J ; 46(1): 53-7, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19115789

RESUMO

Cleft palate is a commonly observed congenital maxillofacial defect. One of the most important problems with clefts is the interference with feeding. An affected infant cannot produce negative pressure in the oral cavity and therefore cannot move the bolus backward to the pharynx. To obtain better nutritional intake prior to surgical correction, a palatal lift obturator is recommended. In this clinical report, a modified technique of obturator fabrication is presented. The new method uses a piece of tulle, a flexible and durable material that is frequently used in theater attire. With the help of this material, the bulb part is connected to the plate as a labile piece, and this connection acts like a natural velopharyngeal extension. Additionally, because of the softer property of the silicone elastomer, the posterior pharyngeal wall is less irritated.


Assuntos
Fissura Palatina/fisiopatologia , Obturadores Palatinos , Palato Mole/fisiopatologia , Comportamento de Sucção , Insuficiência Velofaríngea/fisiopatologia , Resinas Acrílicas , Fissura Palatina/complicações , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/terapia , Humanos , Recém-Nascido , Masculino , Cuidados Pré-Operatórios , Pressão , Desenho de Prótese , Telas Cirúrgicas , Têxteis , Insuficiência Velofaríngea/complicações
15.
Quintessence Int ; 39(7): 603-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19107269

RESUMO

OBJECTIVE: To investigate the effect of the accelerated aging process on the color stability of feldspathic ceramic treated with dual ion exchange, overglaze, polishing, and autoglaze surface treatments. METHOD AND MATERIALS: A total of 40 disks (15 mm in diameter and 2 mm thick) of feldspathic ceramic were made in an A2 shade according to the manufacturer's recommendations. The samples were randomly divided into 4 groups: dual ion exchange, overglaze, polishing, and autoglaze. The samples were subjected to conditions in an accelerated aging machine for 150 and 300 hours. Differences in color before and after accelerated aging were calculated using spectrophotometric analyses. Overall color difference (DeltaE) was determined using the CIE L*a*b* system for measuring small color differences. Scanning electron microscopy was used to evaluate the surface texture of samples. Color difference data were evaluated statistically by Kruskal-Wallis and Mann-Whitney U tests, with a significance level of .05. RESULTS: After 150 and 300 hours of accelerated aging, color changes of the 4 surface treatment groups ranged between 0.35 and 1.31 DeltaE units. All DeltaE values were below a quantitative level that would be considered clinically acceptable. Autoglazed samples were the most color stable, followed by ion exchanged, overglazed, and polished test samples. CONCLUSIONS: All groups demonstrated color stability below a quantitative level that would be considered clinically acceptable, but long-term clinical studies are necessary to verify these findings.


Assuntos
Porcelana Dentária , Pigmentação em Prótese , Silicatos de Alumínio , Cor , Colorimetria , Polimento Dentário , Análise do Estresse Dentário , Troca Iônica , Teste de Materiais , Compostos de Potássio , Distribuição Aleatória , Propriedades de Superfície , Fatores de Tempo
16.
J Prosthet Dent ; 99(3): 185-92, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18319089

RESUMO

STATEMENT OF PROBLEM: In some patients, the pattern of missing teeth may require the use of a fixed partial denture (FPD) with an intermediate pier abutment. Information is needed regarding the biomechanical behavior and the position of a nonrigid connector for this treatment option. PURPOSE: The purpose of this study was to evaluate, by means of finite element method (FEM), the effects of rigid and nonrigid design types on stress distribution for 5-unit FPDs with pier abutments. MATERIAL AND METHODS: A 3-dimensional cross-section FEM model (SAP 2000) simulating a 5-unit metal ceramic FPD with a pier abutment with rigid or nonrigid designs (connector location at the mesial region of the second molar, at the distal region of the second premolar, at the mesial region of the second premolar, and at the distal region of the canine) was developed. In the model, the canine, second premolar, and second molar served as abutments. A supporting periodontal ligament and alveolar bone (cortical and trabecular) were modeled. A 50-N static vertical occlusal load was applied on the cusp of each abutment to calculate the stress distributions. Three different types of load were evaluated: loading of all cusps to simulate maximum centric occlusion contacts, loading of the canine to simulate a single anterior contact, and loading of the second molar to simulate a posterior contact. RESULTS: The analysis of the von Mises stress values revealed that maximum stress concentrations were located at the load areas for all models. Also, for all models, the highest stress values were located at connectors and cervical regions of abutment teeth, especially at the pier abutment. CONCLUSIONS: The area of maximum stress concentration at the pier abutment was decreased by the use of a nonrigid connector at the distal region of the second premolar.


Assuntos
Dente Suporte , Materiais Dentários/química , Planejamento de Dentadura , Prótese Parcial Fixa , Processo Alveolar/fisiologia , Dente Pré-Molar/fisiologia , Fenômenos Biomecânicos , Força de Mordida , Simulação por Computador , Dente Canino/fisiologia , Oclusão Dentária Central , Elasticidade , Análise de Elementos Finitos , Humanos , Imageamento Tridimensional/métodos , Teste de Materiais , Modelos Biológicos , Dente Molar/fisiologia , Ligamento Periodontal/fisiologia , Estresse Mecânico , Ápice Dentário/fisiologia , Raiz Dentária/fisiologia
17.
Dent Mater J ; 27(6): 775-9, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19241684

RESUMO

The purpose of this research was to investigate if physical properties could be improved by incorporating a tulle reinforcement material into a maxillofacial silicone elastomer. A-2186 silicone elastomer was used in this study. The study group consisted of 20 elastomer specimens incorporated with tulle and fabricated in dumbbell-shaped silicone patterns using ASTM D412 and D624 standards. The control group consisted of 20 elastomer specimens fabricated without tulle. Tensile strength, ultimate elongation, and tear strength of all specimens were measured and analyzed. Statistical analyses were performed using Mann-Whitney U test with a statistical significance at 95% confidence level. It was found that the tensile and tear strengths of tulle-incorporated maxillofacial silicone elastomer were higher than those without tulle incorporation (p < 0.05). Therefore, findings of this study suggested that tulle successfully reinforced a maxillofacial silicone elastomer by providing it with better mechanical properties and augmented strength--especially for the delicate edges of maxillofacial prostheses.


Assuntos
Dimetilpolisiloxanos/química , Elastômeros de Silicone/química , Têxteis , Elasticidade , Humanos , Teste de Materiais , Prótese Maxilofacial , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração
18.
J Craniofac Surg ; 18(5): 1086-90, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17912089

RESUMO

A facial defect results in cosmetic, functional, and psychologic problems and acts as a difficult and challenging procedure for the maxillofacial surgeon and the prosthodontist. Retention of a facial prosthesis is an important key in the patient's satisfaction and acceptance. The introduction of extraoral implant applications have been accepted as an advanced retention method. The purpose of this article is to report the results from our clinical experience with patients wearing facial prostheses anchored to extraoral ITI implants (Straumann, AG, Basel, Switzerland).


Assuntos
Pavilhão Auricular , Traumatismos Faciais/reabilitação , Deformidades Adquiridas Nasais/reabilitação , Implantes Orbitários , Próteses e Implantes , Implantação de Prótese/métodos , Pavilhão Auricular/anormalidades , Deformidades Adquiridas da Orelha/reabilitação , Humanos , Masculino , Pessoa de Meia-Idade
19.
Int J Prosthodont ; 19(1): 37-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16479758

RESUMO

PURPOSE: The purpose of this in vitro study was to demonstrate the dentinal tubule-occluding effect of desensitizing laser treatment on dentin surfaces using environmental scanning electron microscopy (E-SEM). MATERIALS AND METHODS: Ground dentin surfaces were divided into 5 areas. Each area received a different mode of laser irradiation (low potency [LP] versus high potency [HP] and short time [ST] versus long time [LT]). Lased dentin surfaces were viewed and graded under E-SEM at x5000 magnification. RESULTS: The tubule closure rates of 4 different irradiation modes were as follows: LP/LT (74%) > HP/ST (70%) > LP/ST (51%) > HP/LT (46%) > control (6%). CONCLUSION: It was demonstrated that desensitizing laser application was an efficient treatment option for the occlusion of dentinal tubule apertures.


Assuntos
Sensibilidade da Dentina/radioterapia , Dentina/efeitos da radiação , Terapia a Laser , Dentina/ultraestrutura , Humanos , Terapia com Luz de Baixa Intensidade/métodos , Microscopia Eletrônica de Varredura , Doses de Radiação , Fatores de Tempo
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