RESUMEN
Resumen Un material de retroobturación como el MTA (Mineral Trioxide Aggregate) debe de ser de fácil manejo, biocompatible, tener baja o nula solubilidad y ser dimensionalmente estable para evitar filtraciones asociadas a los cambios volumétricos. Objetivo: Medir la filtración en un cemento dental tipo MTA modificado con wollastonita y vidrio bioactivo. Material y métodos: Se establecieron ocho grupos: MTA Angelus (control), MTA Exp (cemento Portland blanco más 20 wt% de trióxido de bismuto), otros seis grupos se formaron con la adición de 10, 20 y 30 wt% de wollastonita y vidrio bioactivo al MTA Exp. Dientes permanentes uniradiculares, raíz recta y con ápice cerrado fueron preparados con técnica crown-down con fuerzas balanceadas para obtener un diámetro estandarizado a lima apical maestra #40. Se cortaron 3 mm del ápice se prepararon retrocavidades de 3 mm de profundidad con punta de ultrasonido donde fueron colocados los cementos, el extremo apical fue sumergido en solución de azul de metileno al 2% durante 24 horas. Resultados: MTA Exp fue el que presentó menor filtración con un promedio de 0.66 mm, mientras que el grupo de WO10 fue el de mayor con 1.61 mm. MTA Angelus usado como control presentó 0.71 mm de microfiltración, se encontraron diferencias estadísticamente significativas con WO10, (ANOVA p < 0.001, Dunett p < 0.001). Conclusiones: Se observa que en el caso de los cementos con los agregados de wollastonita y vidrio bioactivo la microfiltración disminuye conforme aumenta el porcentaje del agregado, se sugiere el uso de otras técnicas complementarias para medir la microfiltración.
Abstract Retro-filling material such as MTA (mineral trioxide aggregate) should be biocompatible, easy to handle, with low or nil solubility as well as dimensionally stable in order to avoid filtrations associated to volumetric changes. Objective: To measure filtration in a MTA-type dental cement modified with wollastonite and bioactive glass. Material and methods: Eight groups were established: MTA Angelus (control), MTA Exp (white Portland cement plus 20% wt of bismuth trioxide), another six groups were formed with the addition to MTA Exp of 10, 20 and 30% wt of wollastonite and bioactive glass . Single rooted teeth, with straight root and closed apex were prepared with crown-down technique with balanced forces in order to obtain standardized diameter to fit a number 40 master apical file; 3 mm from the apex were excised, 3 mm deep retro-cavities were prepared with ultrasound point, where cements were placed, apical end was submerged in a 2% methylene blue solution for 24 hours. Results: MTA Exp exhibited least filtration with an average of 0.66 mm, WO10 group exhibited the greatest leakage with average of 1.61 mm. MTA Angelus, used as control exhibited 0.71 mm microleakage. Statistically significant differences were found with WO10, (ANOVA p < 0.001), Dunett p < 0.001). Conclusions: It was observed that in the case of cements with aggregate of wollastonite and bioactive glass, microleakage decreased according to the aggregate's percentage. For microleakage measurement, use of other supporting techniques is advised.
RESUMEN
Glass ionomer cement (GIC) has the unique fluoride release property and able to form ionic bond with tooth structure. However, the brittleness of the material results in low hardness. In the present study, a new approach in utilization of local waste materials as fillers for improvement of hardness of GIC is reported. The synthesized wollastonite and mine-silica by-product were individually incorporated into commercial GIC and the Vickers hardness were evaluated. The results shown that the incorporation of 1 % wollastonite into GIC gave ~ 6 % increment in hardness compared to the control GIC (66.53HV ± 7.37 versus 62.66HV ± 2.98) but not for the mine-silica. Thus, wollastonite could be a potential material to be utilized as fillers in dental restorative composite.
RESUMEN
PURPOSE: To investigate in vivo reaction of newly developed glass-ceramic, we inserted an iliac crest prosthesis using apatite- and wollastonite-containing glass-ceramic. The efficacy and side effect of this prosthesis, if any, were studied clinically and radiologically. MATERIALS AND METHODS: A full-thickness bone graft of the iliac crest was made in 20 patients who needed revisional surgery for THR loosening. Different sized blocks (ranging from 3 cm to 7 cm in length) of bioactive glass-ceramic prosthesis were made and implanted in a complete and large bony deficiency of the iliac crest. The postoperative follow-up period ranged from 8 to 13 months (average 11 months). Following the operations, clinical and radiological examinations were performed postoperatively at 2 weeks, 3, 6 and 12 months. RESULTS: Clinically, no foreign body reactions, including swelling and irritation, were noted. Radiologically, no displacement and no breakdown of the iliac prostheses were seen 11 months after surgery and the radiolucent line between the prosthesis and the iliac bone gradually disappeared with time in all cases. CONCLUSIONS: The apatite- and wollastonite-containing glass-ceramic supplementation for the iliac bony defect was successful experimentally and this glass-ceramic, which contains sufficient mechanical strength and can strongly bond with host bone, may be a promising prosthesis in the repair of large bone defect.