Comparison of dental dimensions in models developed with digital procedures and plaster models / Comparación de dimensiones dentales en modelos desarrollados con procedimientos digitales y modelos en yeso

Aim: This study aimed to collect evidence on the validity and reliability of measurements obtained from digital impression techniques. Materials and Methods: This comparative study was conducted on 31 patients. Intraoral scanner was applied to all patients. For each patient, an alginate impression of the upper maxilla was taken and later the 3D digital model was extracted by dental cone-beam computed tomography (CBCT). For preparation of plaster models, alginate impressions were taken and immediately poured with dental stone. In the next stage, a comparison was performed among the intraoral scanner, CBCT, and plaster models in terms of tooth size, dental width, and intra-arch dimensions. Results: Measuring tooth size and intra-arch dimensions in digital images obtained from intraoral scanner and CBCT were in most cases lower than the results obtained in the plaster models but the differences between digital techniques and plaster models are not clinically noticeable. Conclusions: Digital systems including intraoral scanner and CBCT are acceptable for clinical use in terms of accuracy.

Objetivo: Este estudio tuvo como objetivo recopilar evidencia sobre la validez y confiabilidad de las mediciones obtenidas a partir de técnicas de impresión digital. Materiales y Métodos: Este estudio comparativo se realizó en 31 pacientes. A todos los pacientes se les aplicó escáner intraoral. Para cada paciente, se tomó una impresión de alginato del maxilar superior y posteriormente se extrajo el modelo digital 3D mediante Tomografía computarizada de haz cónico (CBCT) dental. Para la preparación de los modelos de yeso se tomaron impresiones de alginato y se vertieron inmediatamente con yeso dental. En la siguiente etapa, se realizó una comparación entre el escáner intraoral, CBCT y los modelos de yeso en términos de tamaño de diente, ancho dental y dimensiones intraarcada. Discusión: Se encontró que la apariencia microscópica de las células fusiformes era comparable en ambos grupos. Los resultados de la citometría de flujo demostraron expresiones comparables en ambos grupos, siendo las muestras positivas para CD90, CD73, CD105, HLA ABC y negativas para CD34, CD45 y HLA DR. Hubo variaciones en la expresión de los marcadores cuando se evaluaron los potenciales de diferenciación. Conclusión: Los sistemas digitales como el escáner intraoral y el CBCT son aceptables para uso clínico en términos de precisión.

Effect of ibuprofen and low-intensity pulsed ultrasound on the reduction of pain after initial archwire placement: a double-blind randomized clinical trial / Efecto del ibuprofeno y el ultrasonido pulsado de baja intensidad en la reducción del dolor después de la colocación inicial del arco de ortodoncia: un ensayo clínico aleatorizado doble ciego

Objective: This study aimed to compare the effect of ibuprofen and low intensity pulsed ultrasound (LIPUS) on the reduction of pain after the placement of initial archwire in orthodontic patients. Material and Methods: This double-blind clinical trial study was carried out on 60 female candidates for fixed orthodontic treatment referring to the Orthodontic Department of School of Dentistry in Mashhad University of Medical Sciences, Mashhad, Iran, during 2015-2016. The subjects were divided into four groups of ibuprofen, LIPUS, placebo, and mock LIPUS. A questionnaire and a rectangular and flexible cubic silicone were given to each patient to record the severity of pain based on the visual analog scale at specified time points (i.e., 2 h, 6 h, at bedtime, 2nd, 3rd, and 7th days after archwire placement) when biting the silicone block with the anterior and posterior teeth and without biting at all. Repeated measures analysis of variance was used in order to compare the pain severity at different time points. Results: The comparison of pain severity at various time points showed that the highest and lowest mean scores of pain were reported at bedtime and seven days after the intervention (p<0.001). In each of the three conditions (i.e., biting the silicone block with the anterior and posterior teeth and without biting the teeth) at six time points (i.e., 2 h, 6 h, at bedtime, 2nd, 3rd, and 7th days following archwire placement), no significant difference was observed in the severity of pain (p>0.05). Conclusion: In conclusion, LIPUS (with a frequency of 1 MHz and an intensity of 100 mW) and ibuprofen have no significant effects on reduction of the pain severity at different time points and various conditions in orthodontic patients.

Objetivo: Este estudio tuvo como objetivo comparar el efecto del ibuprofeno y el ultrasonido pulsado de baja intensidad (LIPUS) en la reducción del dolor después de la colocación del arco inicial en pacientes de ortodoncia. Material y Métodos: Este estudio de ensayo clínico doble ciego se llevó a cabo en 60 candidatas a tratamiento de ortodoncia fija referidas al Departamento de Ortodoncia de la Facultad de Odontología de la Universidad de Ciencias Médicas de Mashhad, Mashhad, Irán, durante 2015-2016. Los sujetos se dividieron en cuatro grupos: ibuprofeno, LIPUS, placebo y LIPUS simulado. Se entregó un cuestionario y un bloque de silicona cúbica rectangular y flexible a cada paciente para registrar la intensidad del dolor según la escala analógica visual en puntos de tiempo específicos (es decir, 2 h, 6 h, hora de acostarse, 2do, 3er y 7mo día después de la colocación del arco) al morder el bloque de silicona con los dientes anteriores y posteriores, y sin morder en absoluto. Se utilizó el análisis de varianza de medidas repetidas para comparar la intensidad del dolor en diferentes momentos.Resultados: La comparación de la intensidad del dolor en varios puntos de tiempo mostró que las puntuaciones medias de dolor más altas y más bajas se informaron a la hora de acostarse y siete días después de la intervención (p<0,001). En cada una de las tres condiciones (es decir, al morder el bloque de silicona con los dientes anteriores y posteriores, y sin morder) en seis momentos (2 h, 6 h, antes de acostarse 2do, 3er y 7mo día después de la colocación del arco), no se observó diferencia significativa en la severidad del dolor (p>0.05).Conclusión: En conclusión, LIPUS (con una frecuencia de 1 MHz y una intensidad de 100 mW) y el ibuprofeno no tienen efectos significativos en la reducción de la severidad del dolor en diferentes puntos de tiempo y diversas condiciones en pacientes de ortodoncia.

Comparison of the High Cycle Fatigue Behavior of the Orthodontic NiTi Wires: An in Vitro Study

Abstract Objective: To compare the high-cycle fatigue behavior of four commercially available NiTi orthodontic wires. Material and Methods: Twelve NiTi orthodontic wires, round, 0.016-in, three per brand, were selected and divided into four groups: G1 - Heat-activated NiTi, G2 - Superelastic NiTi, G3 - Therma-Ti, and G4 - CopperNiTi. The atomic absorption spectrometry method was used to determine the chemical composition of investigated NiTi wires. We also performed a fatigue test at three-point bending using a universal testing machine for 1000 cycles in a 35 °C water bath. For the first and thousandth cycle, the average plateau load and the plateau length were determined in the unloading area of the force versus displacement diagram. In addition, we calculated the difference between the average plateau load of the first and thousandth cycle (∆F), as well as the difference between the plateau length of both cases (∆L). Results: According to our results, there were no significant differences between the average plateau load of the first and thousandth cycles of each group (p>0.05) and in the plateau length of the first and thousandth cycles of the groups (p>0.05). Conclusion: There were no significant differences between the groups changing the superelasticity property after high-cycle fatigue.

The effect of canine disimpaction performed with temporary anchorage devices (TADs) before comprehensive orthodontic treatment to avoid root resorption of adjacent teeth

ABSTRACT Objective: The aim of this study was to evaluate the movement of impacted canines away from the roots of neighboring teeth before full-mouth bracket placement, performed by means of TADs to decrease undesired side effects on adjacent teeth. Methods: The study sample consisted of 34 palatally impacted canines, being 19 in the experimental group and 15 in the control group. In the experimental group, before placement of brackets, the impacted canine was erupted by means of miniscrews. In the control group, after initiation of comprehensive orthodontics, canine disimpaction was performed by means of a cantilever spring soldered to a palatal bar. At the end of treatment, volume of lateral incisors and canine root resorption were measured and compared by means of a CBCT-derived tridimensional model. Visual Analogue Scale (VAS) score, bleeding on probing (BOP) and gingival index (GI) were recorded. Clinical success rate was also calculated. Results: The volume of root resorption of lateral teeth in the control group was significantly greater than in the experimental group (p < 0.001). At the end of treatment, VAS score, GI and BOP were not significantly different between the two groups. Conclusion: Based on our results, it seems that disimpaction of canines and moving them to the arch can be done successfully carried out with minimal side effects by means of skeletal anchorage.

RESUMO Objetivo: o objetivo do presente estudo foi avaliar o uso de dispositivos de ancoragem temporária (DATs) para a movimentação de caninos impactados, afastando-os das raízes dos dentes vizinhos, antes da colagem dos braquetes em todos os dentes, com o objetivo de minimizar os efeitos colaterais indesejáveis nesses dentes adjacentes. Métodos: a amostra consistiu de 34 caninos impactados por palatino, sendo 19 no grupo experimental e 15 no grupo controle. No grupo experimental, antes da colagem dos braquetes, os caninos impactados foram tracionados utilizando-se mini-implantes. No grupo controle, após o início do tratamento ortodôntico, a desimpacção dos caninos foi realizada com uma mola em cantiléver soldada a uma barra transpalatina. Ao fim do tratamento, os valores referentes à reabsorção radicular nos incisivos laterais e caninos foram medidos e comparados por meio de modelos tridimensionais reconstruídos a partir de TCFCs. Foram também registrados os escores relativos à dor sentida pelos pacientes, usando uma escala visual analógica (VAS); além do Índice de Sangramento à Sondagem (ISS) e do Índice Gengival (IG). O índice de sucesso clínico também foi calculado. Resultados: o volume de reabsorção radicular nos incisivos laterais no grupo controle foi significativamente maior do que no grupo experimental (p < 0,001). Ao fim do tratamento, não houve diferença significativa entre os dois grupos quanto aos escores relativos à VAS, ao IG e ISS. Conclusão: esses resultados sugerem que a desimpacção de caninos e a movimentação deles para a arcada dentária podem ser realizadas, com sucesso e com mínimos efeitos colaterais, por meio da ancoragem esquelética.