Results: 259

Deformation of nickel-titanium closed coil springs: an in vitro study

ABSTRACT Objective: The aim of this paper was to determine the amount of deformation in four commercial brands of nickel-titanium closed springs. Methods: A total of 130 springs were divided into 13 subgroups, according to their features and manufacturers (Morelli, Orthometric, Ormco and GAC) and acti...

Assessment of rotary and reciprocating movements in root canal filling material removal

The aim of this study was to evaluate the effects of preparation, filling removal material, reinstrumentation and reobturation of root canals with different Ni-Ti alloys in endodontic retreatment. Firstly, the selection and pairing of mesial root canals of mandibular molars (n = 45) were performed by com...

Alterações morfológicas e químicas do esmalte humano após o clareamento dental: avaliação in situ

Introdução: A alteração de cor dos dentes apresenta-se como um dos fatores que mais concorrem para o desequilíbrio do sorriso, sendo o clareamento dental amplamente difundido e solicitado pelos pacientes. Objetivo: Este estudo in situ teve como objetivo avaliar as mudanças morfológicas e químicas...

Análise in vivo da modulação óssea em implantes de titânio com superfície em nanoescala

Nas últimas décadas houve um aumento considerável na utilização dos implantes metálicos para aplicações na área da ortopedia e odontologia, por isso as pesquisas têm como foco estudar os mecanismos biológicos de interação osso-implante. A nanotopografia de superfície de implantes osseointeg...

Avaliação do efeito de modificações topográficas e químico-estruturais de superfícies de titânio no potencial osteogênico de células tronco mesenquimais e pré-osteoblásticas

Os efeitos de modificações topográficas e químico-estruturais em superfícies de implantes e sua relação com o comportamento celular na interface com o biomaterial, não foram totalmente elucidados. Avaliou-se o efeito de modificações na topografia, composição química e estrutura cristalina de...

A study of the modification of Y-TZP and resin cement with titanium dioxide nanotubes

Titanium dioxide nanotubes (TiO2) have been applied to enhance the mechanical properties of dental materials. Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) has been increasingly used in dentistry. Aside from its optimal clinical results, Y-TZP is prone to failures related to insufficient thi...

Evaluation of deflection forces of orthodontic wires with different ligation types

Abstract The aim of this study was to evaluate deflection forces of orthodontic wires of different alloys engaged into conventional brackets using several ligation types. Stainless steel, conventional superelastic nickel-titanium and thermally activated nickel-titanium archwires tied into conventional br...

Clinical performance and failure modes of pulpless teeth restored with posts: a systematic review

Abstract The aim of this systematic review was to compare the clinical performance and failure modes of teeth restored with intra-radicular retainers. A search was performed on PubMed/Medline, Central and ClinicalTrials databases for randomized clinical trials comparing clinical behavior and failures of ...

Characterization and coating stability evaluation of nickel-titanium orthodontic esthetic wires: an in vivo study

Abstract The objective of this study was to compare coating dimensions and surface characteristics of two different esthetic covered nickel-titanium orthodontic rectangular archwires, as-received from the manufacturer and after oral exposure. The study was designed for comparative purposes. Both archwire...

In situ effect of titanium tetrafluoride varnish on enamel demineralization

Abstract The effect of a 4% titanium tetrafluoride (TiF 4 ) varnish on enamel demineralization was evaluated. Twelve volunteers participated in this double-blind, randomized crossover study. Six enamel specimens were positioned in intraoral appliances throughout four treatment stages: 4% TiF 4 varnish (e...