RESUMEN
Os autores apresentam o caso de uma paciente submetida 7 anos após aplicação de polimetilmetacrilato (PMMA) a um facelift com implante de prótese mentoniana, o qual evoluiu com granuloma por corpo estranho em região distante da aplicação do preenchimento. Após quase um ano de tratamento, a paciente evoluiu com resolução do caso.
The authors present the case of a patient who underwent a facelift with a chin implant 7 years after polymethylmethacrylate (PMMA) implantation, which evolved with foreign body granuloma in a region distant from the filling application. After nearly a year of treatment, the patient evolved with resolution of the granuloma.
Asunto(s)
Humanos , Femenino , Persona de Mediana Edad , Historia del Siglo XXI , Prótesis e Implantes , Ritidoplastia , Células Gigantes de Cuerpo Extraño , Granuloma de Cuerpo Extraño , Polimetil Metacrilato , Rellenos Dérmicos , Prótesis e Implantes/normas , Ritidoplastia/efectos adversos , Ritidoplastia/métodos , Células Gigantes de Cuerpo Extraño/patología , Granuloma de Cuerpo Extraño/cirugía , Granuloma de Cuerpo Extraño/patología , Granuloma de Cuerpo Extraño/terapia , Polimetil Metacrilato/normas , Polimetil Metacrilato/uso terapéutico , Procedimientos de Cirugía Plástica , Procedimientos de Cirugía Plástica/métodos , Cara , Cara/cirugía , Rellenos Dérmicos/uso terapéuticoRESUMEN
Microwave irradiation has been used for disinfection of dentures instead of chemical solutions; yet, its effect on resin properties after repeated procedures still is unclear. This study evaluated the cumulative effect of two disinfection methods on Knoop microhardness and tridimensional stability of a poly(methyl methacrylate) denture base resin. For the microhardness measurement, 24-resin discs received mechanical polishing and were submitted to the following treatments: (1) control (no disinfection), (2) chemical disinfection (immersion in 100ppm chloride solution for 24h), or (3) microwave disinfection (irradiation at 690 W for 6 min). Disinfection procedures were performed twice (T1, T2) with a 7-day interval. Knoop microhardness was recorded after polishing (T0) and after T1 and T2. For the dimensional stability test (measured by the adaptation of the denture bases), 36-maxillary denture bases were obtained from type III dental stone casts duplicated from a metallic master model and submitted to the disinfection treatment. Adaptation of denture bases was measured at baseline (T0) and after T1 and T2 by weighing a vinyl polysiloxane film reproducing the gap between resin base and master model. Data were analyzed by ANOVA GLM for repeated measures and Bonferroni's test, alpha = 0.05. Knoop microhardness was not modified by any disinfection procedure but decreased over time. Denture resin bases submitted to microwave disinfection had gradual increase of distortion over time, while bases immersed in chloride solution did not differ from the control group and remained dimensionally stable from T1 to T2.
Asunto(s)
Resinas Compuestas/química , Desinfección/métodos , Polimetil Metacrilato , Cloruros , Resinas Compuestas/normas , Materiales Dentales/química , Materiales Dentales/normas , Desinfección/normas , Mecánica , Microondas , Polimetil Metacrilato/normas , Polimetil Metacrilato/uso terapéuticoRESUMEN
This work reports on the effect of the amount (0, 10, and 30 wt %) and type of HA powder incorporated into an acrylic bone cement on the tensile properties, compression properties, and fracture toughness. The three different types of HA powders used were synthesized in the laboratory and coated with a silane agent prior to incorporation into the cement powder, and differed in particle size, water content, surface area, and crystallinity. It was found that the inclusion of any type of HA powder led to an increase in the tensile modulus (ET), but all the other mechanical properties of the cement decreased (relative to the values of the unfilled cement). The increase in ET is attributed to the good adhesion between the filler and the cement matrix, which is due to the silane coating agent. The decrease in the other mechanical properties may be a consequence of HA powder agglomeration and porosity. Hydroxyapatite morphology and crack-growth mechanisms were analyzed by scanning electronic microscopy (SEM).