Assessment of apical pressures at different automated irrigant flow rates: an ex vivo study based on computational fluid dynamic analysis / Avaliação de pressões apicais em diferentes taxas de fluxo irrigante automatizadas: um estudo ex vivo baseado em análise dinâmica de fluidos computacionais

Objective: The current study aimed at assessing the induced apical pressure at various simulated irrigant flow rates. Materials and Methods: Forty eight freshly extracted single-rooted premolars were decoronated and prepared to size 30 0.04 taper using HY-Flex CM rotary file system and were scanned using cone-beam computed tomography (CBCT). The scanned images were reconstructed to three-dimensional Computer-aided design models (CAD) and the 3D needle was also reconstructed. Finally, simulations were done by placing the 30 gauge open-ended needle 3 mm short of the working length. Results: There was a statistically significant difference (p<0.05) among the different groups compared. 1 ml/min flow rate induced the least apical pressures (p<0.05) as compared to the other types. Conclusion: 1 ml/min flow rates induced the least apical pressures when open-ended needles are used for irrigation.(AU)

Objetivo: O presente estudo teve como objetivo avaliar a indução de pressão apical em várias taxas de fluxo irrigante simuladas. Material e Métodos: Quarenta e oito raízes de pré-molares unirradiculares recém extraídos tiveram suas coroas removidas, foram preparados para uma conicidade de tamanho 30 0.04 através de um sistema rotatório de limas HYFlex CM e foram escaneados via tomografia computadorizada cone-beam (CBCT). As imagens escaneadas e as agulhas para irrigação foram reconstruídas em modelos tridimensionais de design assistido por computador (CAD). Ao final, foram feitas simulações através de agulhas de calibre 30 e 3 mm a menos que o comprimento de trabalho. Resultados: Houve diferença estatisticamente significativa (p<0.05) entre os diferentes grupos. A taxa de fluxo de 1 ml/min induziu as menores pressões apicais (p<0.05) quando comparada às demais taxas. Conclusão: Taxas de fluxo de 1 ml/min induziram as menores pressões apicais quando agulhas de ponta aberta foram utilizadas para irrigação (AU)

Effects of cervical mobilization and exercise on pain, movement and function in subjects with temporomandibular disorders: a single group pre-post test

ABSTRACT Objective To investigate the effect of a rehabilitation program based on cervical mobilization and exercise on clinical signs and mandibular function in subjects with temporomandibular disorder (TMD). Material and Methods: Single-group pre-post test, with baseline comparison. Subjects Twelve women (22.08±2.23 years) with myofascial pain and mixed TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders. Outcome measures Subjects were evaluated three times: twice before (baseline phase) and once after intervention. Self-reported pain, jaw function [according to the Mandibular Functional Impairment Questionnaire (MFIQ)], pain-free maximum mouth opening (MMO), and pressure pain thresholds (PPTs) of both masseter and temporalis muscles were obtained. Baseline and post-intervention differences were investigated, and effect size was estimated through Cohen’s d coefficient. Results Jaw function improved 7 points on the scale after the intervention (P=0.019), and self-reported pain was significantly reduced (P=0.009). Pain-free MMO varied from 32.3±8.8 mm to 38±8.8 mm and showed significant improvement (P=0.017) with moderate effect size when compared to the baseline phase. PPT also increased with moderate effect size, and subjects had the baseline values changed from 1.23±0.2 kg/cm2 to 1.4±0.2 kg/cm2 in the left masseter (P=0.03), from 1.31±0.28 kg/cm2 to 1.51±0.2 kg/cm2 in the right masseter (P>0.05), from 1.32±0.2 kg/cm2 to 1.46±0.2 kg/cm2 in the left temporalis (P=0.047), and from 1.4±0.2 kg/cm2 to 1.67±0.3 kg/cm2 in the right temporalis (P=0.06). Conclusions The protocol caused significant changes in pain-free MMO, self-reported pain, and functionality of the stomatognathic system in subjects with myofascial TMD, regardless of joint involvement. Even though these differences are statistically significant, their clinical relevance is still questionable.

Static compression regulates OPG expression in periodontal ligament cells via the CAMK II pathway

ABSTRACT Objective This study aimed to investigate the potential role of CAMK II pathway in the compression-regulated OPG expression in periodontal ligament cells (PDLCs). Material and Methods The PDL tissue model was developed by 3-D culturing human PDLCs in a thin sheet of poly lactic-co-glycolic acid (PLGA) scaffolds, which was subjected to static compression of 25 g/cm2 for 3, 6 and 12 h, with or without treatment of KN-93. After that, the expression of OPG, RANKL and NFATC2 was investigated through real-time PCR and western blot analysis. Results After static compression, the NFATC2 and RANKL expression was significantly up-regulated, while partially suppressed by KN-93 for 6 and 12 h respectively. The OPG expression was significantly down-regulated by compression in 3 h, started to elevate in 6 h, and significantly up-regulated in 12 h. The up-regulation after 12 h was significantly suppressed by KN-93. Conclusions Long-term static compression increases OPG expression in PDLCs, at least partially, via the CAMK II pathway.

Influência da aplicação e manutenção de pressão na tampa da mufla durante a presa do gesso, na movimentação dos dentes de uma dentadura / Effect of application and pressure maintenance on the flask top during the plaster setting in the changing of position of artificial teeth of a complete denture

O objetivo deste trabalho foi verificar a pressão exercida pelo excesso de água empregada na manipulação do gesso e confinada no interior da mufla, proveniente da aplicação e manutenção de pressão sobre a tampa, durante o fechamento, provocaria a movimentação dos dentes. Para isso, foram construídas 15 dentaduras superiores, 5 para cada uma de 3 técnicas de inclusão, onde uma era considerada como normal, outra, onde o fechamento da mufla era feito e a tampa mantida sob pressão, e uma terceira, onde no fechamento a tampa era adaptada e mantida sem pressão. As alterações das posições dos dentes foram observadas medindo-se as distâncias previamente marcadas. As alterações das posições dos dentes foram observadas medindo-se as distâncias previamente marcadas, entre os segundos pré-molares e entre os molares, estando as dentaduras enceradas e após a polimerização, porém, sem a remoção do modelo. Os resultados mostraram que o emprego ou não de pressão sobre o gesso, durante o processo de inclusão da dentadura, não interfere na movimentação dos dentes.