RESUMEN
Keloids present a challenging clinical problem due to their propensity for recurrence and need for adjuvant therapy. We present a case where a large keloid resection required free tissue transfer and immediate radiation therapy was employed 24 hours postoperatively. There were no significant issues with flap survival, wound healing, or recurrence 2 years postoperatively. This is the first case report of successful radiation treatment 1 day after reconstruction of the head and neck with a free flap. Laryngoscope, 131:E1818-E1820, 2021.
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Colgajos Tisulares Libres/trasplante , Queloide/radioterapia , Queloide/cirugía , Cuello , Terapia Combinada , Humanos , Queloide/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Cicatrización de HeridasRESUMEN
To date, the outcomes of cartilage repair have been inconsistent and have frequently yielded mechanically inferior fibrocartilage, thereby increasing the chances of damage recurrence. Implantation of constructs with biochemical composition and mechanical properties comparable to natural cartilage could be advantageous for long-term repair. This study attempted to create such constructs, in vitro, using tissue engineering principles. Bovine synoviocytes were seeded on nonwoven polyethylene terephthalate fiber scaffolds and cultured in chondrogenic medium for 4 weeks, after which uniaxial compressive loading was applied using an in-house bioreactor for 1 h per day, at a frequency of 1 Hz, for a further 84 days. The initial loading conditions, determined from the mechanical properties of the immature constructs after 4 weeks in chondrogenic culture, were strains ranging between 13% and 23%. After 56 days (sustained at 84 days) of loading, the constructs were stained homogenously with Alcian blue and for type-II collagen. Dynamic compressive moduli were comparable to the high end values for native cartilage and proportional to Alcian blue staining intensity. We suggest that these high moduli values were attributable to the bioreactor setup, which caused the loading regime to change as the constructs developed, that is, the applied stress and strain increased with construct thickness and stiffness, providing continued sufficient cell stimulation as further matrix was deposited. Constructs containing cartilage-like matrix with response to load similar to that of native cartilage could produce long-term effective cartilage repair when implanted.
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Cartílago , Condrogénesis , Tereftalatos Polietilenos/química , Membrana Sinovial , Ingeniería de Tejidos , Andamios del Tejido/química , Animales , Cartílago/citología , Cartílago/metabolismo , Bovinos , Colágeno Tipo II/biosíntesis , Estrés Mecánico , Membrana Sinovial/citología , Membrana Sinovial/metabolismoRESUMEN
Although all cases should be approached comprehensively, restoring a limited segment in the esthetic zone presents challenges particularly related to microesthetics. Microesthetics are those criteria related to the subtle intricacies of shade, textures, translucencies, and surface effects that make teeth look like teeth. These are the criteria that aid dentists in fooling the eye and allowing restorations to blend invisibly into the smile. Completing a comprehensive assessment of a patient ensures that the restorative foundation will remain biologically and structurally predictable, durable, and above all, esthetically pleasing. Starting esthetic treatment without first doing a comprehensive assessment will result in a compromised result. Within the criteria of microesthetics, the utilization of a common nomenclature and quantitative means of communication between the restorative dentist and the laboratory ceramist are at the core of success. The use of prototypes during the provisionalization phase and progressive techniques in digital photography are invaluable tools. Along with traditional techniques in acquiring proper shade selection, the use of cross-polarization filters has been proven to be an effective way to eliminate spectral artifacts typically found in flash photography. Additionally, the use of a color-corrected master die system provides the ceramist a method to calibrate shades on the lab bench by capturing images--via the cross-polarization filters--that are similar to what is observed clinically.
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Restauración Dental Permanente , Estética Dental , Adulto , Femenino , HumanosRESUMEN
OBJECTIVES: To compare fatigue resistance and fracture mode of metal-ceramic crowns with all-ceramic crowns containing yttria tetragonal zirconia polycrystal (Y-TZP) frameworks under compressive cycling loading in water. METHODS: Twenty specimens of ivory were randomized and individually prepared to receive anatomically shaped metal-ceramic (n=10) or veneered Y-TZP all-ceramic crowns (n=10). All steps in production were equivalent to clinical situations. Resistance to fatigue fracture was tested under compressive cyclic loading using a universal testing machine, with a loading frequency of 12Hz using a spherical tungsten carbide indenter (6mm diameter) in distilled water. The maximum compressive load was increased as the number of cycles increased (600,000 cycles at 400N, 200,000 cycles at 600 N, 200,000 cycles at 800 N and 200,000 cycles at 1000 N). The specimens were inspected after each loading sequence for initial failures such as infractions. Final failure was considered as any loss of material which automatically ended the test and the number of cycles until final failure was recorded. Fractographic analysis of the fractured specimens was performed with scanning electron microscopy (SEM). RESULTS: The two types of crowns exhibit similar fatigue resistance (P=0.87) to compressive cycling loading under wet conditions. The failure modes as observed with SEM were similar in the two groups and were found in the veneer ceramic, except that three veneered Y-TZP all-ceramic crowns displayed a complete framework fracture. CONCLUSIONS: Within the limitation of this study using simulated oral masticatory function, the results revealed that the fatigue resistance was similar for the two crown types. CLINICAL SIGNIFICANCE: In this study metal-ceramic crowns and veneered Y-TZP all-ceramic crowns showed similar fracture resistance to compressive cycling loading in water. The test conditions were simulating clinical conditions. Thus, the result may predict the long-term clinical performance of these types of crowns.