Influence of different working lengths on the shaping ability of Reciproc Blue in the apical third and apical foramen: a micro-computed tomographic study

Aim: This study aimed to assess the shaping ability of Reciproc Blue in the apical third and apical foramen of moderately curved canals at different working lengths (WLs), by micro-computed tomography. Methods: Thirty-six mesial roots (mesiobuccal and mesiolingual canals) were included, each with 2 separate root canals and independent apical foramina, according to type IV of Vertucci's classification of first and second mandibular molars. The canals were instrumented at three different WLs: G-1, 1mm short of the major apical foramen; G0, at the major apical foramen; G+1, 1mm beyond the major apical foramen. The groups were assessed for changes in root canal volume and untouched wall area in the apical third. Groups G0 and G+1 were also compared for percentage of untouched walls at the apical foramen. One-way ANOVA (post hoc Tukey test) and Student's t-test adopted a 5% level of significance. Results: Root canal volumes (mm3) in the apical third were 22.86±10.46, 44.48±24.91, and 55.71±21.32 in G-1, G0 and G+1, respectively. G-1 volume following instrumentation increased significantly less than that of G0 or G+1 (P>.05); G0 did not differ from G+1. The percentage of untouched wall area in the apical third did not differ among the three groups (P>.05). G0 and G+1 did not differ regarding untouched walls in the major apical foramem walls. Conclusion: Extending the WL from 1mm short of the apical foramen to a point at and beyond the WL increases the apical third volume without increasing the prepared area. Untouched surface areas of the apical foramen were not modified by instrumentation at or beyond the foramen

Os pricipais efeitos colaterais do clareamento dentário: como amenizá-los / Tooth whitening: main T collateral effects and how to smooth them

Introdução: em busca de uma perfeita harmonia na forma e nas cores dos dentes, a dentística desenvolveu diversas alternativas para a melhoria da estética dentária, sendo que para o tratamento das alterações cromáticas, o procedimento mais utilizado atualmente é o clareamento dental. Objetivo: realizar uma revisão de literatura a cerca dos possíveis efeitos colaterais advindos das técnicas de clareamento dental e como minimizá-los. Material e Métodos: revisão de literatura por meio de busca bibliográfica nas bases de pesquisa online: PubMED, Medline, Lilacs, Scielo e Scopus, através do rastreio de artigos relevantes publicados entre o período de 2010 a 2016. Resultados: dentre os efeitos colaterais apresentados pelo clareamento dental, a sensibilidade durante e após o clareamento tem sido um dos efeitos adversos mais apontados na literatura, fato que pode ser resultado do aumento da permeabilidade do esmalte, com uma possível difusão do peróxido até a polpa, os tratamentos mais eficazes no controle da sensibilidade são: nitrato de potássio a 5%, fluoreto de sódio neutro a 2%, a terapia a laser e o uso de analgésicos e anti-inflamatórios. O gel clareador deve ser removido totalmente ao final do clareamento, porém se alguma quantidade do mesmo é deixada para trás, o paciente pode eventual deglutir, o que pode levar a irritação na mucosa gastrointestinal, dessa forma é importante que seja evitado o excesso de produto e de aplicações, atentando com a remoção cuidadosa dos excessos, para evitar sua ingestão e contato com tecidos moles. Conclusão: independentemente da técnica de clareamento a ser utilizada é necessária a supervisão e acompanhamento de um cirurgião-dentista, pois com o seu criterioso diagnóstico e adequado tratamento é que os resultados satisfatórios serão alcançados e os efeitos colaterais evitados e/ou minimizados. (AU)

Introduction: in order to achieve a perfect harmony in the shape and colors of the teeth, the dentistry has developed several alternatives for the improvement of dental aesthetics, and for the treatment of chromatic alterations, the most commonly used procedure is tooth whitening. Objective: to carry out a literature review about the possible side effects of dental bleaching techniques and how to minimize them. Material and Methods: a review of the literature was carried out through a bibliographic search in the following online databases: PubMED, Medline, Lilacs, Scielo and Scopus, through the screening of relevant articles published between 2010 and 2016. Results: among the side effects of tooth whitening, sensitivity during and after bleaching has been one of the most commonly reported adverse effects in the literature, a fact that may be a result of increased permeability of the enamel, with a possible diffusion of the peroxide to the pulp. The most effective treatments for sensitivity control are: 5% potassium nitrate, 2% neutral sodium fluoride, laser therapy and the use of analgesics and anti-inflammatories. The bleaching gel should be removed completely at the end of bleaching, but if any amount is left behind, the patient may eventually swallow, which may lead to irritation in the gastrointestinal mucosa, so it is important to avoid excess product And applications, with the careful removal of excess, to avoid its ingestion and contact with soft tissues. Conclusion: regardless of the technique of whitening to be used, it is necessary the supervision and follow-up of a dental surgeon, because with his careful diagnosis and appropriate treatment, satisfactory results will be achieved and the side effects avoided and/or minimized. (AU)