António Ginjeira

Worldwide Prevalence of Mandibular Second Molar C-Shaped Morphologies Evaluated by Cone-Beam Computed Tomography

Introduction The aim of this study was to evaluate and compare the C‐shaped mandibular second molar prevalence in different regions around the world with the aid of cone‐beam computed tomography technology. Methods Nine field observers from 9 different geographic regions were calibrated. A total of 400 samples were collected in each region. The prevalence of C‐shaped anatomy was calculated. The number of roots and the configuration of the C‐shaped canals at 3 different axial levels were also evaluated. The z‐test was used to analyze the difference between the means of each independent group. Intrarater reliability was also tested. Results A total of 3600 teeth from 2735 patients were included in this research; 499 teeth presented C‐shaped root canal configuration, representing a global prevalence of 13.9%. China had a prevalence of 44.0%, which was significantly higher than any other region. The C‐shape prevalence in women was 16.5%, which was significantly higher than the 10.4% prevalence found in men. No difference between sides (37 or 47) was evident in the global sample. Conclusions Cone‐beam computed tomography is a valuable tool to evaluate the C‐shaped root canal configuration in vivo. In the present study, China presented the highest prevalence of C‐shaped mandibular second molars when compared with other regions. Women exhibited a higher prevalence than men.

Glossário de Termos Endodônticos

The existence of a glossary of contemporary endodontic terminology was long felt need for everyone with a particular focus on this area of knowledge, who want and need to communicate, and therefore feeling the necessity that the terminology has a precise meaning and simultaneously that it will be understood by others, even from different schools. The fast technological and scientific development of Endodontics has determined a permanent evolution of the used lexicon, and so any glossary must be perceived as something dynamic, evolving constantly, something that it will be updated regularly and will not stay fossilized in time. This is the second of three papers, which are our contribution to the Glossary of Endodontic terminology Key-words: Glossary; Endodontics; Terminology (Capelas JA, Albuquerque B, Paulo S, Ferreira MM, Ginjeira A. Glossário de Termos Endodônticos Parte II. Rev Port Estomatol Cir Maxilofac 2008;49:57-62) *Médico Dentista, Professor Associado de Endodôncia da FMDUP ** Médico Dentista, docente voluntário de Endodôncia da FMUC *** Médico Dentista, Assistente de Endodôncia da FMUC ****Médico Dentista, Assistente de Endodontia da FMDUL Continuamos nesta II parte a nossa contribuição para um glossário de termos endodônticos. Esperamos vir a contar com as contribuições dos colegas interessados no tema, de forma a manter o nosso léxico sempre actualizado. • Galvanismo (electrogalvanismo) – fluxo de corrente eléctrica directa entre dois ou mais metais não similares; pode ocorrer na cavidade oral, quando restaurações com materiais metálicos de diferentes composições entram em contacto, resultando em sensações de vários graus. • Geminação – distúrbio durante a odontogenese no qual ocorre clivagem do gérmen dentário resultando num dente com uma “dupla coroa”. Usualmente estas coroas não estão completamente separadas e partilham uma mesma raiz e espaço pulpar. • Gluteraldeído – óleo tóxico (C5H8O2) solúvel na água, comummente utilizado numa solução de 2% para desinfecção, esterilização e fixação de tecidos. • Granuloma – massa tumoral delimitada, composta por elementos inflamatórios, resultante de uma irritação crónica, como restaurações mal adaptadas, espículas ósseas, introdução de substâncias químicas ou causas bacterianas. É constituído por elementos angioblásticos, células inflamatórias e elementos fibroblásticos. • Granuloma de reabsorção interna – destruição de dentina à volta da câmara pulpar ou canal radicular, pela acção de teciINTRODUÇÃO Glossário de Termos Endodônticos

Computer fluid dynamics as a tool for analysis of endodontic irrigation

Endodontic treatment aims to prevent and treat pulp and periradicular diseases, mainly through mechanical and chemical procedures. The mechanical preparation is critical for successful chemical irrigation and disinfection, as it assures that it can reach all the pulp canal system. This is mostly important where the anatomy is more complex, such as in the mesial roots of lower molars. The aim of this study was to examine the suitability of using computer fluid dynamics (CFD) for endodontic irrigation in the pulp canal system. We were mostly interested in examining the properness of this methodology to compare different mechanical preparations. Data were obtained from mandibular molar roots, scanned by computed tomography (CT) providing a three-dimensional object that was exported to the computer-assisted design (CAD) software. CAD model of an 27G side-vented irrigation needle was created and placed 3mm from the apical foramen. The flow pattern, irrigant re-placement, velocity distribution, wall stress distribution, and apical pressure in the canal can be analysed with the proposed methodology. This approach showed that CFD may be a useful tool for endodontists to evaluate the requirements in attaining a wider mechanical preparation. That will produce a better fluid dynamic of the irrigant inside, where the anatomy of the root canal is more complex, possibly leading to a better disinfection.Endodontic treatment aims to prevent and treat pulp and periradicular diseases, mainly through mechanical and chemical procedures. The mechanical preparation is critical for successful chemical irrigation and disinfection, as it assures that it can reach all the pulp canal system. This is mostly important where the anatomy is more complex, such as in the mesial roots of lower molars. The aim of this study was to examine the suitability of using computer fluid dynamics (CFD) for endodontic irrigation in the pulp canal system. We were mostly interested in examining the properness of this methodology to compare different mechanical preparations. Data were obtained from mandibular molar roots, scanned by computed tomography (CT) providing a three-dimensional object that was exported to the computer-assisted design (CAD) software. CAD model of an 27G side-vented irrigation needle was created and placed 3mm from the apical foramen. The flow pattern, irrigant re-placement, velocity distribution, wall stress dist...

Worldwide Analyses of Maxillary First Molar Second Mesiobuccal Prevalence: A Multicenter Cone-beam Computed Tomographic Study

Introduction: Maxillary first molar second mesiobuccal (MB2) root canal prevalence may change among different populations. The aim of this study was to analyze the worldwide prevalence of the MB2 root canal and understand its possible relation with sex, age, side, and root configuration using in vivo cone‐beam computed tomographic (CBCT) assessment. Methods: Observers from 21 regions were calibrated to achieve a similar CBCT assessment methodology and instructed to collect data from 250 maxillary first molars in previously existing examinations. Intra‐ and interrater reliability tests were performed. The sample size included 5250 molars and was defined by way of a preliminary trial. Data collected included MB2 presence, sex, age, side, number of roots per tooth, and mesiobuccal root configuration. The z test for proportions in independent groups was used to analyze the differences among subgroups. P < .05 was considered significant. Results: The worldwide CBCT‐assessed MB2 prevalence was 73.8%, ranging from 48.0% in Venezuela to 97.6% in Belgium. The prevalence in males and females was 76.3% and 71.8%, respectively (P < .05). Significantly higher MB2 proportions were found in younger patients and 3‐rooted molar configurations. The group intraclass correlation coefficient and the percentage of agreement for the MB2 presence were 0.95 and 0.91, respectively. The intrarater Cohen kappa value was above 0.61 for all observers. Conclusions: MB2 prevalence in the analyzed regions varied widely. The differences may be associated with specificities within each region but also patient demographics. Males, younger patients, and 3‐rooted configurations were associated with higher MB2 proportions.

Intracoronal Whitening of Endodontically Treated Teeth

Several techniques have been used within the last 170 years to lighten discolored endodontically treated teeth. Internal whitening or intracoronal whitening offers some advantages over more invasive treatments, as: (1) it is relatively easy to carry out; (2) it involves the removal of minimal tooth structure; and (3) the cost of treatment is low compared to that of other restorative options including full- and partial-coverage restorations.

Glossário de Termos Endodônticos: Parte III☆

Resumo A existencia de um glossario de termos endodonticos era uma necessidade sentida desde ha muito por todos aqueles que se dedicam mais a esta area da Medicina Dentaria, e que querem e precisam de comunicar entre si, sendo fundamental que a terminologia tenha significado preciso e facilmente perceptivel por colegas oriundos de escolas diferentes. O rapido desenvolvimento tecnologico e cientifico da Endodontia tem determinado uma evolucao constante do lexico utilizado, e nessa conformidade qualquer glossario deve ser encarado como algo dinâmico, em constante evolucao, pretendendo-se que nao cristalize no tempo, mas antes se actualize permanentemente. Este e o terceiro e ultimo de tres artigos, que sao a nossa contribuicao para um Glossario de Termos Endodonticos em Portugues.