ABSTRACT
PURPOSE: A technique whereby the practitioner could improve the esthetic appearance of anterior stainless steel crowns (SSC) could provide a cost-effective alternative to more expensive commercially available preveneered SSCs, which may not be uniformly available. The purpose of this study was to evaluate the effects of ultraviolet (UV) irradiation of the metal crown surface on the shear bond strength of composite resin adhered to stainless steel crowns. METHODS: Seventy extracted anterior bovine teeth randomly divided into 2 groups (n=35/group), were restored with primary maxillary left central incisor SSCs. Surface roughening with a green stone was performed on the labial surfaces, and the crowns of the experimental group were exposed to UV irradiation for 80 minutes. All samples were treated with metal-composite adhesive, followed by composite opaquer. Standardized composite blocks were bonded on the treated surfaces, and the shear bond strength was tested at 1 mm/minute. The values were recorded in MPa and statistically analyzed. RESULTS: The mean value of shear bond strength was significantly higher for the experimental group (19.7 ± 4.3 MPa) than the control group (16.3 ± 4.5 MPa). CONCLUSION: Ultraviolet irradiation of primary tooth stainless steel crowns significantly increased the shear bond strength of composite resin adhered to the facial surface.
Subject(s)
Composite Resins/radiation effects , Crowns , Dental Alloys/radiation effects , Dental Bonding , Dental Materials/radiation effects , Stainless Steel/radiation effects , Ultraviolet Rays , Adhesiveness , Animals , Cattle , Cementation/methods , Composite Resins/chemistry , Dental Alloys/chemistry , Dental Materials/chemistry , Dental Stress Analysis/instrumentation , Esthetics, Dental , Glass Ionomer Cements/chemistry , Incisor/pathology , Magnesium Oxide/chemistry , Polycarboxylate Cement/chemistry , Random Allocation , Shear Strength , Stainless Steel/chemistry , Stress, Mechanical , Surface Properties , Time Factors , Zinc Oxide/chemistryABSTRACT
La mordida cruzada es una relación vestibulolingual inversa o anormal al contacto de los dientes u oclusión fisiológica, por lo que es de vital trascendencia su diagnóstico y tratamiento. En lo que respecta al tratamiento existe gran variedad de aparatos para solucionar esta patología, por esto se realizó un estudio comparativo entre dos aparatos de expansión maxilar: el Quad-Helix y la Placa de expansión en paralelo. Dentro de los parámetros a valorar se tomó en cuenta el tiempo de solución del problema, el incremento en mm que se lograba, número de visitas que se requerían, costo del aparato, el tiempo de su elaboración, así como su estabilidad y durabilidad