Influência da penetração de instrumentos, empregados na condensação lateral ativa, na qualidade da obturação de canais radiculares

PURPOSE: the purpose of this study was to compare the quality of the obturation and the difference of penetration depth inside the root canal of the instruments Finger Spreader, file type Kerr, Flexofile and Nitiflex when used as spreaders during the filling by Active Lateral Condensation Technique. MATERIAL AND METHOD: 40 extracted permanent human teeth were instrumented by the Modified Goerig Technique and divided in four groups. In the group I the finger spreader was used; in the group II, files type Kerr was used; in the group III, files Flexofile was used and, in the group IV, files Nitiflex, all number 30, for space opening for placement of the secondary cones, during the Technique of Active Lateral Condensation. The radiographic quality of the obturation and the depth of penetration of the instruments was evaluated and analysed statisticaly (Kruskal-Wallis and Dunn's Test). RESULTS AND CONCLUSION: with relationship to the radiograph analysis of the quality of the filling, the group II was what it presented the best result, followed by the groups I, IV and III, respectively. In relation to the depth of penetration of the instruments, the group IV approached more the desired distance, or, 1 millimeter less than the length of the work, followed, respectively, by groups II, III and I.OBJETIVO: comparar a qualidade da obturação e a diferença de profundidade de penetração, no interior do canal radicular, dos espaçadores digitais (Finger Spreader), limas tipo Kerr, Flexofile e Nitiflex, quando utilizados como espaçadores, durante a obturação pela Técnica da Condensação Lateral Ativa. MATERIAL E MÉTODOS: foram utilizados 40 dentes molares permanentes humanos, extraídos, instrumentados pela Técnica de Goerig Modificada e divididos em quatro grupos. No grupo I foi utilizado o espaçador digital C; no grupo II, lima tipo Kerr; no grupo III, lima Flexofile e, no grupo IV, lima Nitiflex, todos com diâmetro (D1) ou diâmetro da ponta correspondente ao diâmetro de uma lima 30 (0,30mm), para abertura de espaço para colocação dos cones secundários, durante a Técnica da Condensação Lateral Ativa. Avaliou-se e submeteu-se à análise estatística (Kruskal-Wallis e teste de Dunn) a qualidade radiográfica da obturação e a profundidade de penetração dos instrumentos. RESULTADOS E CONCLUSÃO: quanto à análise radiográfica da qualidade da obturação, o grupo II foi o que apresentou o melhor resultado, seguido dos grupos I, IV e III, respectivamente. Em relação à profundidade de penetração dos instrumentos, o grupo IV aproximou-se mais da distância desejada, ou seja, 1 milímetro aquém do comprimento de trabalho, seguido, respectivamente, dos grupos II, III e I

Efficacy of the NaviTip FX irrigation needle in removing calcium hydroxide from root canal

Objective: To evaluate the effectiveness of the NaviTip FX, brush-covered irrigation needle, in removing calcium hydroxide from the root canal. Study Design: Thirty single-rooted teeth were randomly divided into three groups: A - irrigation with a hypodermic needle inserted as far as possible without binding and activation with #30 K-type file; B - Irrigation with a hypodermic needle without activation; C - irrigation with NaviTip FX needle. Sodium hypoclorite 1% was used in irrigation. The root canals were examined trough scanning electron microscopy. Calcium hydroxide removal was recorded at 1, 5, and 10mm from the working length (WL) and the data were analysed using one-way ANOVA test (p<0.05). Results: NaviTip FX and hypodermic needle activated with #30K-type file showed lower score at 10 and 5mm with no significant difference between them. Comparison within groups did not show significant differences. All groups showed significantly better smear layer removal at 5 and 10 mm from the WL. Conclusion: The apical third (1mm) of the root canal was found to be the most critical site for Ca(OH)2 removal

A scanning electron microscopic study of hypercementosis

The purpose of this study was to evaluate morphological characteristics of teeth with hypercementosis that are relevant to endodontic practice. Twenty-eight extracted teeth with hypercementosis had their root apexes analyzed by scanning electron microscopy (SEM). The teeth were divided according to tooth groups and type of hypercementosis. The following aspects were examined under SEM: the contour and regularity of the root surface; presence of resorption; presence and number of apical foramina, and the diameter of the main foramen. The progression of club shape hypercementosis was directly associated with the presence of foramina and apical foramen obstruction. Cases of focal hypercementosis presented foramina on the surface, even when sidelong located in the root. Circular cementum hyperplasia form was present in 2 out of 3 residual roots, which was the highest proportion among the tooth types. The detection of a large number of foramina in the apical third of teeth with hypercementosis or even the possible existence of apical foramen obliteration contributes to understand the difficulties faced during endodontic treatment of these cases

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

HYPERCEMENTOSIS: MACROSCOPIC, STEREOMICROSCOPY, RADIOGRAPHIC AND SCANNING ELECTRON MICROSCOPIC STUDY

A hipercementose é caracterizada pela formação excessiva de cemento além do limite necessário para cumprir suas funções normais resultando em espessamento anormal com alteração da forma macroscópica da raiz. Inicialmente, procedeu-se à realização do exame macroscópico e estereomicroscópico e radiográfico de 576 dentes permanentes humanos com hipercementose em espécimes pertencentes ao Departamento de Patologia da Faculdade de Odontologia de Bauru - Universidade de São Paulo. Os critérios morfológicos analisados radiograficamente foram o término do canal principal, canais secundários, acessórios, delta apical, constrição apical e observação da hipercementose e sua junção com a dentina. Selecionaram-se 28 dentes e analisaram-se seus ápices radiculares à microscopia eletrônica de varredura. Verificou-se que a progressão da hipercementose em forma de clava está diretamente associada ao fechamento gradativo das foraminas e forames apicais; a forma focal de hipercementose apresenta foraminas em sua superfície, mesmo quando lateralmente localizadas nas raízes dentárias; a hipercementose em forma de boca de manga de camisa acomete principalmente raízes residuais. Sendo assim, o clínico, nas várias especialidades, durante a escolha da técnica terapêutica, deve considerar as variações anatômicas interna e externa dos dentes portadores de hipercementose, visto que radiograficamente não é possível, com precisão e segurança, determinar essas variações e suas implicaçõesHypercementosis is characterized by the excessive formation of the cementum beyond its physiological limits resulting in abnormal thickening with alteration of the macroscopic root appearance. This study analyzed 576 permanent human teeth with hypercementosis though macroscopic and stereomicroscopy means. The teeth were radiographed and some morphologic aspects were observed such as: the end of the main root canal, secondary and accessories canals, apical delta, apical constriction, hypercementosis manifestation and its junction with the dentin. Out of these specimens 28 were selected and analyzed its root apexes through scanning electron microscopy. It was verified that the progression of hypercementosis in club form is directly associated to foraminas and apical foramen obstruction; the focal form of hypercementosis presents foraminas in its surface, even they are sidelong located in its dental roots; the hypercementosis in "shirt mouth sleeve form" attacks mainly residual roots. Based in these findings it must be considered during dental practice a proper therapeutic technique and also the teeth's anatomical variations due to hypercementosis, since it is not possible with accuracy and safety to determine radiographically, the anatomical modifications and its implication

HYPERCEMENTOSIS: MACROSCOPIC, STEREOMICROSCOPY, RADIOGRAPHIC AND SCANNING ELECTRON MICROSCOPIC STUDY

A hipercementose é caracterizada pela formação excessiva de cemento além do limite necessário para cumprir suas funções normais resultando em espessamento anormal com alteração da forma macroscópica da raiz. Inicialmente, procedeu-se à realização do exame macroscópico e estereomicroscópico e radiográfico de 576 dentes permanentes humanos com hipercementose em espécimes pertencentes ao Departamento de Patologia da Faculdade de Odontologia de Bauru - Universidade de São Paulo. Os critérios morfológicos analisados radiograficamente foram o término do canal principal, canais secundários, acessórios, delta apical, constrição apical e observação da hipercementose e sua junção com a dentina. Selecionaram-se 28 dentes e analisaram-se seus ápices radiculares à microscopia eletrônica de varredura. Verificou-se que a progressão da hipercementose em forma de clava está diretamente associada ao fechamento gradativo das foraminas e forames apicais; a forma focal de hipercementose apresenta foraminas em sua superfície, mesmo quando lateralmente localizadas nas raízes dentárias; a hipercementose em forma de boca de manga de camisa acomete principalmente raízes residuais. Sendo assim, o clínico, nas várias especialidades, durante a escolha da técnica terapêutica, deve considerar as variações anatômicas interna e externa dos dentes portadores de hipercementose, visto que radiograficamente não é possível, com precisão e segurança, determinar essas variações e suas implicaçõesHypercementosis is characterized by the excessive formation of the cementum beyond its physiological limits resulting in abnormal thickening with alteration of the macroscopic root appearance. This study analyzed 576 permanent human teeth with hypercementosis though macroscopic and stereomicroscopy means. The teeth were radiographed and some morphologic aspects were observed such as: the end of the main root canal, secondary and accessories canals, apical delta, apical constriction, hypercementosis manifestation and its junction with the dentin. Out of these specimens 28 were selected and analyzed its root apexes through scanning electron microscopy. It was verified that the progression of hypercementosis in club form is directly associated to foraminas and apical foramen obstruction; the focal form of hypercementosis presents foraminas in its surface, even they are sidelong located in its dental roots; the hypercementosis in "shirt mouth sleeve form" attacks mainly residual roots. Based in these findings it must be considered during dental practice a proper therapeutic technique and also the teeth's anatomical variations due to hypercementosis, since it is not possible with accuracy and safety to determine radiographically, the anatomical modifications and its implication