RESUMO
PURPOSE: To evaluate the effect of replacement of inadequate complete dentures on salivary flow and taste perception in geriatric patients. MATERIALS AND METHODS: Thirty-three patients, 13 males and 20 females, with a mean age of 64.4 years were submitted to stimulated and unstimulated salivary flow rate and salivary pH measurements, and sense of taste evaluation. Tests were performed 3 months before complete denture substitution and 3 weeks after denture insertion. RESULTS: The mean for unstimulated saliva (USS) was 2.1 ml before and 2.7 ml after replacement (p = 0.003). The mean volume of stimulated saliva was 6.3 ml before and 8.2 ml after replacement (p = 0.004). The pH mean of USS was 7.8 ± 0.44 before and 8.02 ± 0.41 after replacement (p = 0.005). No statistically significant difference was determined in the sense of taste before and 3 weeks after complete denture replacement. CONCLUSIONS: The replacement of inadequate complete dentures increases saliva flow; however, it does not improve taste perception.
Assuntos
Prótese Total , Salivação , Paladar , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: To determine the effects of different aging methods on the degradation and flexural strength of yttria-stabilized tetragonal zirconia (Y-TZP) METHODS: Sixty disc-shaped specimens (∅, 12mm; thickness, 1.6mm) of zirconia (Vita InCeram 2000 YZ Cubes, VITA Zahnfabrik) were prepared (ISO 6872) and randomly divided into five groups, according to the aging procedures (n=10): (C) control; (M) mechanical cycling (15,000,000 cycles/3.8Hz/200N); (T) thermal cycling (6,000 cycles/5-55°C/30s); (TM) thermomechanical cycling (1,200,000 cycles/3.8Hz/200N with temperature range from 5°C to 55°C for 60s each); (AUT) 12h in autoclave at 134°C/2bars; and (STO) storage in distilled water (37°C/400 days). After the aging procedures, the monoclinic phase percentages were evaluated by X-ray diffraction (XRD), and topographic surface analysis was performed by 3D profilometry. The specimens were then subjected to biaxial flexure testing (1mm/min, load 100kgf, in water). The biaxial flexural strength data (MPa) were analyzed by 1-way ANOVA and Tukey's test (α=0.05). The data for monoclinic phase percentage and profilometry (Ra) were analyzed by Kruskal-Wallis and Dunn's tests. RESULTS: ANOVA revealed that flexural strength was affected by the aging procedures (p=0.002). The M (781.6MPa) and TM (771.3MPa) groups presented lower values of flexural strength than did C (955MPa), AUT (955.8MPa), T (960.8MPa) and STO (910.4MPa). The monoclinic phase percentage was significantly higher only for STO (12.22%) and AUT (29.97%) when compared with that of the control group (Kruskal-Wallis test, p=0.004). In addition, the surface roughnesses were similar among the groups (p=0.165). SIGNIFICANCE: Water storage for 400 days and autoclave aging procedures induced higher phase transformation from tetragonal to monoclinic; however, they did not affect the flexural strength of Y-TZP ceramic, which decreased only after mechanical and thermomechanical cycling.
Assuntos
Cerâmica/química , Materiais Dentários/química , Ítrio/química , Zircônio/química , Algoritmos , Cristalografia , Imageamento Tridimensional/métodos , Teste de Materiais , Maleabilidade , Distribuição Aleatória , Estresse Mecânico , Propriedades de Superfície , Temperatura , Fatores de Tempo , Água/química , Difração de Raios XRESUMO
A literatura mostra escassez de informações sobre o envelhecimento de cerâmicas Y-TZP de uso odontológico. O objetivo deste estudo foi o de avaliar o efeito do envelhecimento in vitro inicial em autoclave e avaliar a curva cinética de transformação de fase através do envelhecimento em reator hidrotérmico pressurizado em zircônia odontológica (Y-TZP). Especificamente: a - identificar o início da degradação, b - avaliar a resistência mecânica após envelhecimento inicial em autoclave, comparar diferentes métodos de leitura quanto à transformação de fase e análise topográfica, d determinar a cinética de cristalização isotérmica por meio do envelhecimento em reator, e -comparar os métodos de quantificação a partir da equação de Garvie e Nicholson e o método de Rietveld. Discos de zircônia (12mm Ø x 1,2mm em espessura) foram divididos em grupos: A) envelhecido em autoclave (n=10); B) envelhecido em reator (n=4). O grupo A foi submetido ao envelhecimento em autoclave (134 oC, 2 bar), em tempos de 6, 15, 30, 42, 60, 90, 144, 198,240, 300 e 360 minutos. O grupo B foi submetido ao envelhecimento em reator (130 oC, 2 bar), em tempos de 6, 8, 10, 12, 14, 20, 30, 40, 48, 60,84, 108 e 138 horas. A caracterização superficial e cristalográfica foi realizada antes e depois em microscopia de força atômica (MFA), Perfilometria óptica, Difração de Raios-X e, também foram realizadas análises em microscopia eletrônica de varredura (MEV) e Raman. O grupo envelhecido em autoclave foi submetido ao teste de flexão biaxial. Os valores de Ra (nm) obtidos em Perfilometria Óptica, os valores de resistência (MPa) e os valores de transformação de fase cristalina t-m (%)foram submetidos à análise de variância de 1 fator e ao teste de Tukey(α=0,05). Houve aumento gradual de concentração de fase mono clínica com o aumento do tempo de envelhecimento em autoclave, da mesma forma que os valores de rugosidade. Os valores de resistência mostraram haver tendência à diminuição com o aumento...
The literature shows a lack of information about Y-TZP aging of dental ceramics. The aim of this study was to evaluate the initial in vitro aging effect and evaluate the kinetic curve of phase transformation through the pressurized hydrothermal reactor of dental zirconium. Specifically: a- the identification of the beginning of degradation; b- evaluation of the mechanical resistance after steam aging; c- compare different methods of phase transformation and topographic analysis, d- determine the kinetic of crystallization through the reactor; e- compare the phase quantification methods between the Garvie and Nicholson equation and RietveldMethod. Discs of zirconium (12mm Ø x 1,2mm thickness) were divided in groups: A) steam aged (n=10); B) Hydrothermal reactor aged (n=4). The group A was submitted to water steam aging (134 oC, 2 bar) for 6, 15, 30,42, 60, 90, 144, 198, 240, 300 and 360 minutes. The group B was submitted to reactor aging (130 oC, 2 bars), for 6; 8; 10; 12; 14; 20; 30; 40;48; 60; 84; 104 and 138 hours. The surface and crystallographic characterization before and after aging were made using atomic force microscopy (AFM), Optical Profilometry, X-ray diffraction (DRX), scanning electron microscopy (SEM) and Raman spectroscopy. The steam aged group was submitted to biaxial flexure test. The values of Ra (nm)obtained by optical profilometry and the crystalline phase transformation values t-m (%) were submitted to One Way ANOVA and Tukeytest(α=0,05). A gradual increase was observed at the monoclinic phase concentration as the time increased and in the same way the roughness values increased. The resistance values demonstrated a tendency todecrease with the increase of aging time. The group aged by the reactor presented the increase of monoclinical phase reaching 60% of saturation through the Garvie and Nicholson equation in 40 hours and 80% in 40hours throughout the Rietveld method
Assuntos
Materiais Dentários , Microscopia EletrônicaRESUMO
A disfunção temporomandibular é um termo aplicado à condição de dor e/ou de disfunção mastigatória, sendo encontrada em 750f0 da população e tem a maloclusão como um dos possíveis fatores predisponentes. Este artigo relata a seqüência de tratamento de uma paciente que apresentava um posicionamento maxilo-mandibular sugestivo de mordida classe III de Angle, com prognatismo mandibular acentuado, mordida cruzada anterior e ausência de suporte posterior. Observou-se a diminuição marcante da dimensão vertical de oclusão que resultava na condição postural mandibular relatada, o que gerou desconforto, dificuldade mastigatória, sintomatologia dolorosa nos músculos elevadores da mandíbula bilateralmente e assimetria facial. O tratamento de eleição consistiu na recuperação da DVO por meio da instalação de uma prótese temporária removível inferior. Além disto, foi feito um "dispositivo anterior" que possibilitou o equilíbrio de contatos em posições excêntricas, além de proporcionar conforto, função e estética. Concluiu-se que a técnica proposta foi de simples aplicação clínica e determinou remissão da sintomatologia dolorosa, além de facilitar a elaboração do planejamento clínico e sua execução.
Temporomandibular dysfunction is a term applied to a pain and/or masticatory dysfunction con- dition, find in 750f0 of population and has malocclusion as one of the potential predisposition factors. This article report a sequence of treatment in one patient that used to present a maxilo-mandibular position suggesting bite Angle's class 111, with an accented mandibular prognathism, anterior crossbite and absence of posterior support. It was observed a pronounced decrease of vertical occlusion dimen- sion that resulted in a mandibular postura I condition related, that generated discomfort, masticatory difficult, painful symptomatology in the bilateral mandibular elevator rnuscles and facial asymmetry. The selected treatment consisted in a vertical dimension of occlusion recovery through the installation of a lower temporary removable prosthesis. Furthermore, it was made an "anterior appliance" that made possible the contacts equilibrium in eccentrics position also provides comfort, function and esthetic. It was concluded that the technique proposal was the simple clinical application and determined painful symptomatology remission, besides facilitating an elaboration of a clinical planninq and execution.