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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.

The objective was to present a way of using cone-beam computed tomographic (CBCT) images to classify alveolar bone tissue. CBCT images were acquired from PreXion3D tomography. Sagittal images of right and left maxillary and mandibular central incisors were obtained. A new grading scale was created based on the presence or absence of bone in each third of the tooth in buccal and lingual surfaces. The tooth was classifi ed into nine alveolar bone conditions: B1L1, B1L2, B1L3, B2L1, B2L2, B2L3, B3L1, B3L2, B3L3. This classifi cation is an additional tool to provide orthodontic and periodontic professionals the precise information needed in order to prevent periodontal problems or to avoid exacerbating them, both situations that might arise during orthodontic therapy. Furthermore, the grading will assist and enhance eff ective communication between professionals in dentistry.