RESUMEN
The purpose of this investigation was to evaluate the outcome of treatment with implant-retained prostheses in patients suffering from Sjögren syndrome. Eight women were included in the study; all had suffered oral symptoms of Sjögren syndrome for many years. Seven patients were edentulous in both arches, and 1 patient was edentulous in the maxilla only. All patients reported poor or very poor comfort levels with their conventional dentures. It was the intention to treat each arch that showed subjective and objective denture problems with a complete fixed prosthesis after placement of 6 implants. In all, 54 Brånemark dental implants were placed in these patients. No implants were lost, but 7 implants in 4 patients were clinically not osseointegrated at the time of the abutment connection procedure. Because of nonosseointegrated implants and lack of jawbone, 3 arches were treated with an implant-retained overdenture. Fixed prostheses were made with a titanium framework of premachined components welded together (Procera) and acrylic resin teeth and flanges. Patients answered a questionnaire regarding their oral function before the onset of treatment and 1 month and 2 years after treatment. An average radiographic bone loss of 0.7 mm from the time of implant placement to 1 year after treatment was observed; additional bone loss of less than 0.6 mm was recorded 4 years after treatment. During the first year of function 2 implants lost osseointegration. No prostheses were lost or remade. Treatment with implant-retained prostheses considerably increased the prosthetic comfort and function of the patients. Two years after prosthetic treatment, only 1 patient indicated poor comfort of the prostheses, while the remaining patients reported good or very good comfort levels.
Asunto(s)
Implantación Dental Endoósea , Implantes Dentales , Prótesis Dental de Soporte Implantado , Síndrome de Sjögren/complicaciones , Resinas Acrílicas , Anciano , Resorción Ósea/diagnóstico por imagen , Pilares Dentales , Porcelana Dental , Fracaso de la Restauración Dental , Bases para Dentadura , Diseño de Dentadura , Dentadura Completa , Prótesis de Recubrimiento , Femenino , Humanos , Enfermedades Mandibulares/diagnóstico por imagen , Enfermedades Maxilares/diagnóstico por imagen , Aleaciones de Cerámica y Metal , Persona de Mediana Edad , Boca Edéntula/diagnóstico por imagen , Boca Edéntula/rehabilitación , Boca Edéntula/cirugía , Oseointegración , Satisfacción del Paciente , Radiografía , Titanio , Resultado del TratamientoRESUMEN
PURPOSE: The purpose of this in vitro study was to evaluate the influence of post and ferrule length on the resistance to cyclic (fatigue) loading of teeth with prefabricated titanium posts (ParaPost) and crowns. MATERIALS AND METHODS: Ninety bovine teeth with similar dimensions were mounted in acrylic blocks with artificial silicone periodontal ligaments. Combinations of post lengths of 5 mm, 7.5 mm, and 10 mm, and ferrule lengths (i.e., the vertical dentinal overlap of the crown) of 0 mm, 1.25 mm, and 2.5 mm made up 9 different groups consisting of 10 teeth each. The posts were cemented with zinc phosphate cement. Composite-resin cores were made and crowns were cemented. Each test specimen underwent cyclic loading of 400 N with a frequency of 1 load per second at an angulation of 45 degrees to the long axis of the tooth. RESULTS: All but 2 specimens failed with a root fracture; in the remaining 2 specimens the core lost retention. A large variation in the results between the various groups was observed. A nonparametric 2-way analysis for groups with a natural order revealed that the fracture resistance to cyclic loading increased statistically significantly with increasing ferrule length (P < 0.01), whereas increasing post length did not increase fracture resistance (P = 0.44). CONCLUSION: Ferrule length was more important than post length in increasing fracture resistance to cyclic loading of crowned teeth.
Asunto(s)
Diseño de Prótesis Dental , Técnica de Perno Muñón/instrumentación , Fracturas de los Dientes/prevención & control , Animales , Bovinos , Análisis del Estrés Dental , Ensayo de Materiales , Estadísticas no Paramétricas , Titanio , Raíz del Diente/lesionesRESUMEN
This in vivo study evaluated the fracture resistance of bovine teeth with prefabricated carbon fiber posts. Fourteen bovine teeth having similar lengths and dimensions were mounted in an acrylic resin block having a simulated periodontal ligament. The post space was prepared using two calibrated drills that provided an 8.5-mm post length. The prefabricated carbon fiber post was luted with a resin luting agent, and the core was made using the system's autopolymerizing resin core material. A crown was luted to each prepared tooth. Each test specimen was intermittently loaded (250 N) at an angulation of 45 degrees to the long axis of the tooth at a frequency of 2 loads per second. Four of the roots had an incomplete longitudinal fracture after loading. The results of this study were compared to a previous study by the authors that had been conducted under similar conditions with prefabricated parallel-sided posts (Para-Post) and tapered, individually cast posts. The failure rates of the two types of posts from the previous study were significantly higher (Logrank test; P<.02) than those of the carbon fiber posts.
Asunto(s)
Técnica de Perno Muñón/instrumentación , Fracturas de los Dientes/prevención & control , Animales , Bisfenol A Glicidil Metacrilato , Carbono , Fibra de Carbono , Bovinos , Coronas , Retención de Prótesis Dentales , Elasticidad , Diseño de Equipo , Humanos , Tablas de Vida , Ensayo de Materiales , Técnica de Perno Muñón/efectos adversos , Titanio , Fracturas de los Dientes/etiología , Raíz del Diente/lesionesRESUMEN
Sparse data are available concerning the survival rate of porcelain inlays or onlays to inform the dentist and address the expectations of patients. A total of 25 posterior porcelain inlays were inserted by two dentists at a private Danish clinic; the time elapsed since cementation was 20 to 57 months (average 40.4 months). Tooth preparations for MOD porcelain inlays were completed for 13 premolars and 12 molars but most did not include cuspal coverage. All inlays were constructed at the same commercial dental laboratory and according to the manufacturer's recommendations; they were etched and treated with silane before they were cemented. The cementation included etching of cavosurface enamel and treatment of the dentin with a dentinal bonding system. A thin layer of composite resin luting agent was applied to the tooth preparation before the porcelain inlays were cemented. The first 10 porcelain inlays were cemented with a light-curing composite resin cement and the remaining 11 with a dual-curing composite resin cement. Twelve of the 25 porcelain inlays failed and were replaced during the observation period. Ten failures were due to a fracture of the inlay, one was caused by secondary caries, and the final failure was attributed to a marginal gap between the inlay and proximal tooth surface. Porcelain inlays cemented with light-curing composite resin exhibited more failures (p = 0.05) than those cemented with dual-curing composite resin. In addition, more failures (p = 0.07) were recorded among inlays inserted in molars than among those in premolars.
Asunto(s)
Cementos Dentales/química , Porcelana Dental , Incrustaciones , Grabado Ácido Dental , Resinas Compuestas/química , Preparación de la Cavidad Dental , Recubrimientos Dentinarios , Humanos , Tablas de Vida , Falla de Prótesis , Análisis de SupervivenciaRESUMEN
This study compared the resistance to intermittent loading of teeth with tapered, individually cast posts and cores or prefabricated parallel-sided posts (Para-Post, Whaledent) and composite cores. Bovine teeth mounted in acrylic resin blocks with a simulated periodontium were used for the study. Two conditions were studied. One group received individually fabricated posts and cores, the second had titanium prefabricated posts and resin composite cores placed. All teeth receiving posts and cores had cast crown restorations placed. Teeth were intermittently loaded using a force of 250 N twice each second at an angle 45 degrees to the long axis until failure occurred. Teeth with prefabricated posts and resin composite cores showed a significantly higher resistance to intermittent loading than did teeth with tapered, individually cast posts and cores. Additional restored teeth were sectioned and the adaptation of the posts to the root were measured. The adaptation of the prefabricated posts was better than that of tapered, individually cast posts.