Premature failure of a screw-retained ceramic single crown: A clinical report and fractographic analysis.

Screw-retained implant-supported ceramic restorations have shown increased rates of technical complications compared with their cemented counterparts, including fracture and chipping of the ceramic structures. The present clinical report identified the causes leading to the catastrophic failure of a screw-retained lithium disilicate veneered crown cemented to a zirconia abutment with a titanium base by using a systematic fractographic approach. A combination of occlusal overloading, a deficient design and inadequate material selection was identified as being responsible for the fracture. These findings highlight the importance of a thorough analysis of the anatomic conditions and loading scenario of screw-retained implant-supported restorations.

Seguimiento a 5 años de prótesis híbrida con subestructura sinterizada. Reporte de caso

RESUMEN: La rehabilitación de rebordes severamente atróficos mediante prótesis híbridas con subestructura cromo-cobalto fabricadas por sinterizado láser asegura el ajuste pasivo, aumentando la estabilidad de los tejidos de soporte a largo plazo. Los controles periódicos y enseñanza de técnicas de higiene son fundamentales para el éxito de rehabilitaciones complejas sobre implantes. El propósito de este reporte de caso es realizar la evaluación clínica y radiográfica a 5 años de prótesis híbridas maxilar y mandibular fabricadas mediante sinterizado láser, encontrándose resultados satisfactorios en la evaluación y seguimiento.

ABSTRACT: Rehabilitation of severely atrophic ridges using hybrid cobalt-chrome substructures manufactured by laser sintering ensures passive fit, increasing support tissue stability. Regular check-ups and the teaching of hygiene techniques are essential for the success of complex implant restorations. The purpose of this case report is to perform a 5-year clinical and radiographic evaluation of hybrid maxillary and mandibular prostheses manufactured using laser sintering, achieving satisfactory results in the evaluation and follow-up.

Polifluoruro de amonio como alternativa de acondicionamiento para laminados ultradelgados de disilicato de litio. Reporte de caso / Ammonium polyfluoride as an alternative for the surface conditioning of ultrathin lithium disilicate veneers. A case report

RESUMEN: Los laminados vitrocerámicos ultradelgados constituyen una alternativa conservadora para la resolución de alteraciones estéticas. Sin embargo, su acondicionamiento con ácido fluorhídrico suele no estar exento de complicaciones, por lo que el uso de un sistema autograbante en base a polifluoruro de amonio (Monobond Etch&Prime, MEP) permite disminuir el riesgo de sobregrabado, simplificando la técnica. El presente reporte presenta el seguimiento a dieciocho meses de un caso clínico resuelto mediante laminados vitrocerámicos acondicionados únicamente con MEP. Caso. Paciente joven con alteraciones estéticas en el sector anterosuperior. Se realizaron preparaciones conservadoras para la confección de laminados ultradelgados en disilicato de litio (e.maxPress). Las vitrocerámicas fueron acondicionadas sólo con MEP y se cementaron con Variolink Esthetic LC. Al año y medio las restauraciones se observaron indemnes, manteniendo un buen ajuste marginal y ausencia de tinciones. Conclusiones. MEP aparece como una alternativa prometedora para reemplazar al ácido fluorhídrico en la cementación de laminados vitrocerámicos.

ABSTRACT: Ultrathin glass-ceramic veneers are a conservative approach for the restorative treatment of aesthetic disorders in the anterior region. However, surface conditioning with hydrofluoric acid of the thin structures can be usually a challenging step. Therefore, the use of a self-etching ceramic primer containing ammonium polyfluoride (Monobond Etch&Prime, MEP) offers a simplified technique with a reduced risk of overetching. Here we present an 18-month follow-up of ultrathin glass-ceramic veneers conditioned with MEP only. Case. Young female patient with an aesthetic disorder in the front region. The four upper incisors were conservatively prepared for ultrathin lithium disilicate (e.maxPress) veneers. Pre-treatment of the glass-ceramics consisted only of MEP application, followed by adhesive cementation with Variolink Esthetic LC. At the 1.5-year recall, the restorations appeared undamaged, with no marginal gap or staining. Conclusions. MEP constitutes a promising alternative to hydrofluoric acid for the adhesive cementation of glass-ceramic veneers.

Explantación y reposición de implante con dehiscencia vestibular en la zona estética. Reporte de caso / Explantation and replacement of an implant with a facial dehiscence in the aesthetic region. Case report

RESUMEN: La incidencia de complicaciones en los tejidos periimplantarios, como recesiones y dehiscencias, ha ido en aumento en los últimos años, principalmente asociados a un incorrecto posicionamiento espacial de los implantes. El objetivo de este reporte de caso es presentar el manejo quirúrgico de una complicación estética debida a la mal posición de un implante en la zona anterior. Caso. Paciente se presenta con recesión mucosa y dehiscencia por vestibular del implante 1.2, causados por su mal posicionamiento. Se realiza explantación mediante llave de alto torque e inserción de un nuevo implante en combinación con regeneración ósea (sticky bone) e injerto de tejido conectivo, lo que recupera la armonía gingival. Conclusión. La explantación conservadora acompañada de regeneración tisular ofrecen una interesante alternativa para el tratamiento de defectos estéticos severos asociados a la mal posición de implantes. La sistematización de este tipo de protocolos es fundamental para mejorar su predictibilidad.

ABSTRACT: An increase in the incidence of peri-implant soft tissue complications, such as facial recession and dehiscence, has been observed in the last years, mainly associated with an incorrect spatial placement of the implants. This case report focuses on the surgical management of an esthetic complication due to an incorrect implant position in the anterior region. Case report. Patient presented with recession and dehiscence in the facial area of implant 1.2, due to its incorrect placement. Explantation was performed with a high torque wrench, followed by the immediate placement of a new implant in combination with bone regeneration (sticky bone) and soft tissue augmentation. Conclusion. The use of atraumatic explantation techniques followed by guided tissue regeneration offers an interesting alternative for the treatment of severe defects in the esthetic region due to incorrectly placed implants. An adequate systematization of these protocols is key to improve their predictability.

Diferentes Protocolos de Grabado Ácido en Dentina; Estudio Micromorfológico / Different protocols for acid etching in dentin; micromorphological study

RESUMEN: El objetivo fue evaluar las características de túbulos dentinarios expuestos por acción de diferentes protocolos de grabado en distintas zonas dentinarias. Se midió densidad tubular y diámetro. Se estudiaron 60 primeros premolares humanos sanos sometidos a tratamiento de endodoncia. Se realizaron cortes de las raíces a 5mm del límite amelocementario y en sentido longitudinal bucolingual, obteniendo mitades iguales (mesial y distal) que se agruparon según tratamiento acondicionador a recibir: Control, EDTA, H3PO4 15 y 45 seg., y H3PO4 15 y 45 seg. + NaOCl. Se realizó análisis en MEB en tres sectores: dentina coronaria, cámara pulpar e inicio del conducto radicular. La comparación entre las secciones se analizó mediante prueba t de Student para datos apareados, fijando valor p<0,05 para significación estadística. Se utilizó programa Infostat versión profesional 2009. No se observaron diferencias significativas en los grupos al comparar densidad tubular para las tres zonas estudiadas. Al comparar diámetro de los túbulos, se obtuvieron valores mayores cuando se acondicionó con ácido ortofosfórico al 45% + NaOCl. Los resultados ponen de manifiesto el comportamiento clínico heterogéneo de las distintas zonas dentinarias luego de diferentes protocolos para adhesión con técnica de grabado total. Protocolo tradicional de acondicionamiento con ácido ortofosfórico al 35% por 15 segundos no asegura grabado uniforme de las tres zonas dentinarias estudiadas. Protocolos donde se aumenta el tiempo de grabado y/o se incorpora NaOCl al 5% por un minuto como agente desproteinizante podrían permitir patrones más predecibles y apropiados de grabado en las tres zonas estudiadas de dientes endodonciados.

ABSTRACT: Evaluate in endodontically treated teeth the effects of different etching protocols on dentinal tubule exposure and diameter at three dentin zones. Sixty healthy first premolars from human volunteers were studied. Each tooth received endodontic treatment. Teeth were transversely sectioned 5 mm below amelocemental junction and longitudinaly sectioned in the buccolingual direction, obtaining two crown halves. Each crown half was grouped according to etching protocol into: Control, EDTA, H3PO4 15 and 45 sec., y H3PO4 15 and 45 seg. + NaOCl. Three dentinal areas were analyzed with scanning electron microscope (SEM) within each tooth: coronal dentin, pulp chamber dentin and the beginning of the root canal. Comparison between dentin zones for each treatment was made with Student's t-test for paired data, using P<0.05 for statistical significance. No significant differences in dentinal tubule exposure within the three studied zones were found. However, when comparing tubule diameter, higher values were obtained at the three dentin zones studied when H3PO4 and NaOCl wer used in combination. The results of this study showed heterogeneous behavior of different dentin zones after exposing them to various total etch protocols. The use of 37% H3PO4 for 15s did not ensure a uniform etch in the three studied zones. Protocols with H3PO4 for 45s with 5%NaOCl for 1 min, incorporated as a deproteinizing agent, could allow more predictable and appropriate etching patterns in endodontically treated teeth.

Esthetic rehabilitation with ultra-thin ceramic veneers and direct mock-up in the treatment of dental erosion ­ case report

Dental erosion is a high prevalence condition characterized by the loss of dental substance due to chemical agents. it can also be associated with physical wear, affecting function and aesthetics. ceramic veneers can provide effective solutions to patients affected by erosive disorders, by means of an indirect approach and minimal intervention. recent advances in cementation techniques and ceramic materials have allowed their use in reduced thicknesses, known as "dental contact lenses" or "ultra-thin veneers". they contribute significantly to the preservation of the dental structures, having excellent mechanical properties and providing satisfactory aesthetic solutions. their manufacture requires rigorous planning and the use of three-dimensional models or mock ups in order to preview the final outcome. case: the aim of this report is to communicate the use of this technique for the treatment and successful 12-months follow-up of a patient affected by dental erosion of the maxillary central incisors. special interest was placed on direct mock-up, which is a simple technique not requiring laboratory steps. luting of the lithium disilicate veneers was carried out with a light-curing resin cement and try-in pastes, yielding a very satisfactory result. conclusion: diagnosis and early treatment of this disorder allows the application of conservative techniques, such as ultra-thin veneers, which are seen as a promising alternative treatment to full coverage restorations and traditional ceramic veneers.

Cerámica libre de metal terminada y caracterizada por pulido manual / Metal free ceramic finished and characterized by manual polishing

RESUMEN: La rehabilitación oral mediante prótesis libres de metal ha dado solución funcional y estética a diversas situaciones clínicas, sin embargo, coronas unitarias anteriores aún son consideradas un gran desafío estético. En ellas, al igual que en estructuras métalo-cerámicas, brillo y lisura superficial se obtienen comúnmente mediante glaseado. Esta técnica puede presentar algunas limitaciones para replicar características de superficie, especialmente en dientes con gran riqueza microanatómica. Caso: El objetivo es presentar la rehabilitación anterior unitaria mediante corona IPS E.max® terminada mediante pulido manual, logrando así ajustes clínicos, personalización microanatómica y una superficie suave y brillante, culminando con un resultado estético muy satisfactorio. Conclusiones: El acabado manual es un procedimiento ampliamente documentado, de fácil ejecución y bajo costo. Podría disminuir envíos repetidos al laboratorio protésico y así los efectos asociados a la sobrecocción cerámica, sin embargo, requiere conocimiento del tipo de cerámica a pulir y una aplicación sistemática.

ABSTRACT: Oral rehabilitation through metal free prosthetics has given functional and aesthetic solutions to various clinical conditions; nevertheless, single-tooth rehabilitation in the anterior region is still considered a major challenge. In these crowns as well as in metallo-ceramic structures, the finishing is obtained by the glazing technique. This technique could show some limitations to replicate the surface characteristics, especially in teeth with a rich micro-anatomy. Case Report: The aim is to present an anterior single-tooth rehabilitation with IPS E.max® crown, and its finishing by hand polishing technique, achieving clinical adjustments and customized surface anatomy, a smooth surface, excellent brightness and a very satisfactory aesthetic result. Conclusions: Manual finishing technique is well documented, easy to execute and with low cost. Eventually, it could decrease repeated laboratory shipments and so the associated effects of the over-cooking of ceramic; nevertheless it requires knowledge of the type of ceramic to polish and a systematic clinical protocol implementation.