RESUMEN
STATEMENT OF PROBLEM: Component fracture and screw loosening are prevalent concerns of contemporary dental implants. PURPOSE: This laboratory investigation examined the influence of design factors such as the platform diameter and the hex height on the mechanical strength and quality of fit of the implant-abutment interface. MATERIAL AND METHODS: Static and cyclic compressive bending tests were conducted on 4 and 5 mm diameter bone density-based implants. SEM evaluation of the implant-abutment interface was also conducted to assess quality of fit between the mating components.Results. The 5 mm diameter implant was stronger in both static and fatigue conditions than the 4 mm diameter implants. A comparison of the results to published literature indicated that both implants were equal to or superior to alternative prosthetic connections in an identical testing configuration. CONCLUSION: Test results demonstrated the validity of wide diameter implants to reduce the likelihood of component fracture in contemporary dental implant systems.
Asunto(s)
Implantación Dental Endoósea/instrumentación , Diseño de Prótesis Dental , Pilares Dentales , Implantación Dental Endoósea/métodos , Implantación Dental Endoósea/estadística & datos numéricos , Diseño de Prótesis Dental/métodos , Diseño de Prótesis Dental/estadística & datos numéricos , Fracaso de la Restauración Dental , Análisis de Falla de Equipo/métodos , Análisis de Falla de Equipo/estadística & datos numéricos , Humanos , Ensayo de Materiales/métodos , Ensayo de Materiales/estadística & datos numéricos , Microscopía Electrónica de Rastreo/instrumentación , Microscopía Electrónica de Rastreo/métodos , Propiedades de Superficie , Resistencia a la TracciónRESUMEN
This work describes the design and construction of a device that facilitates the loading of DNA samples onto polyacrylamide gels for detection in the Perkin Elmer/Applied Biosystems (PE/ABI) 373 and 377 DNA sequencing instruments. The device is mounted onto the existing gel cassettes and makes the process of loading high-density gels less cumbersome while the associated time and errors are reduced. The principle of operation includes the simultaneous transfer of the entire batch of samples, in which a spring-loaded air cylinder generates positive pressure and flexible silica capillaries transfer the samples. A retractable capillary array carrier allows the delivery ends of the capillaries to be held up clear of the gel during loader attachment on the gel plates, while enabling their insertion in the gel wells once the device is securely mounted. Gel-loading devices capable of simultaneously transferring 72 samples onto the PE/ABI 373 and 377 are currently being used in our production sequencing groups while a 96-sample transfer prototype undergoes testing.