RESUMEN
The introduction of nickel-titanium (NiTi) mechanical instruments dramatically changed clinical endodontics over the last few decades. Before NiTi, it was necessary to use more instruments to create an ideal root canal shape, and many approaches, sequences and techniques were developed over the years. Recently, NiTi endodontic instruments have undergone a series of changes brought about by modifications in design, surface treatments, and thermal treatments to improve their root canal preparation outcomes and reduce associated canal preparation risks during root canal treatment. Heat treatment is one of the most fundamental approaches to improving the fatigue resistance and flexibility of NiTi endodontic instruments. In addition, new kinematics have been developed to offer greater safety and efficiency. This narrative review describes the general properties and manufacturing of NiTi instruments, and the mechanical system evolution of NiTi instruments.
Asunto(s)
Aleaciones Dentales , Preparación del Conducto Radicular , Humanos , Preparación del Conducto Radicular/métodos , Níquel , Titanio , Diseño de Equipo , Ensayo de Materiales , Instrumentos DentalesRESUMEN
BACKGROUND: The platform switching concept involves the reduction of the restoration abutment diameter with respect to the diameter of dental implant. Long-term follow up around these wide-platforms showed higher levels of bone preservation. AIM: The aim of this article is to carry out a literature review of studies which deal with the influence of platform-switched implants in hard and soft oral tissues. MATERIALS AND METHODS: All papers involving "platform switching" that are indexed in MedLine and published between 2005 and 2011 were used. Clinical cases, experimental and non-experimental studies were included, as well as literature reviews. RESULTS: In our search, we analized 18 clinical cases and 3 reviews. The results indicate that peri-implant bone resorption is reduced with platform switching system. CONCLUSIONS: All papers written by different researchers show an improvement in peri-implant bone preservation and satisfactory aesthetic results. Further long-term studies are necessary to confirm these results.