An in vitro assessment of the influences of different wire materials and bracket systems when correcting dental crowding.

A recently developed orthodontic wire alloy known as GUMMETAL® is claimed to deliver more physiological forces to correct dental mispositioning. However, its mechanical characteristics have not been fully characterized yet. This study aimed to determine and compare the elastic properties of different wire alloys, such as nickel-titanium (NiTi), stainless steel (SS), and GUMMETAL®, and assess their unloading forces when combined with either conventional or self-ligating brackets (CL and SL) when correcting dental crowding. All wires had a 0.016″ cross-section diameter. A three-point bending test was performed to assess the maximum deflection of each wire. Then, a subsequent analysis measured the unloading force for each wire/bracket system in a dental crowding clinical simulation device. The test was carried out in a universal testing machine with a cross-speed displacement of 0.5 mm/min. Data were recorded in different ranges and statistically evaluated using two-way analysis of variance. GUMMETAL® displayed higher unloading mean forces in SL brackets (2228.78 cN) than CL brackets (1967.38 cN) for the 1.6-3.0 deflection interval (p = 0.018). Within this interval, NiTi showed higher forces when used with CL brackets (2683.06 cN) than with SL brackets (1179.66 cN) (p < 0.0001). For the CL bracket systems, SS wires showed higher forces (2125.31 cN) in the 1.0-1.6 deflection interval than the other two wire alloys (NiTi, 1541.52 cN and GUMMETAL®, 852.65 cN) (p < 0.0001). SS wires also displayed lower forces with SL brackets (1844.01 cN) than in CL brackets (2125.31 cN) (p = 0.049). Thus, only GUMMETAL® revealed to be an optimal choice for SL brackets, whereas NiTi for CL brackets.

Risco perio-ortodôntico: uma sugestão de classificação para diferentes condições de inserção óssea alveolar / Perio-orthodontic risk: a way of classifying different conditions of alveolar bone tissue

A proposta deste artigo foi apresentar uma sugestão de classificação de diferentes condições de inserção óssea alveolar das superfícies vestibular e lingual do elemento dentário em imagens volumétricas tridimensionais geradas pela tomografia computadorizada de feixe cônico. Esta classificação irá auxiliar o ortodontista na avaliação do risco perio-ortodôntico em pacientes adultos, evitando problemas periodontais advindos da terapia ortodôntica, além de permitir uma comunicação mais efetiva entre os profissionais da Ortodontia e da Periodontia.

The purpose of this article is to present a way of using cone-beam computed tomographic images to classify different alveolar bone tissue conditions of buccal and lingual tooth surfaces. This classification will enable the orthodontist to evaluate perio-orthodontic risk in adult patients thus avoiding periodontal problems caused by orthodontic therapy. Furthermore, the grading will assist and enhance effective communication between the orthodontic and periodontic professionals.

Protocolo clínico de desgaste interproximal em dentes posteriores aplicado na técnica lingual / Interproximal enamel reduction protocol in posterior teeth by lingual technique

O desgaste interproximal no esmalte dentário constitui um procedimento comum na prática ortodôntica. O protocolo de execução deve ser preciso e muito bem planejado para evitar desgaste em excesso ou sensibilidade tardia na região. O objetivo do presente trabalho foi descrever passo a passo o desgaste interproximal, assim como mostrar os acessórios utilizados e a sua execução clínica em dentes posteriores.