Constatação e influência da zona crítica de instrumentação, do ângulo de flexão da lima e dos pontos anatômicos no planejamento do desgaste anticurvatura

The anatomy root canal interferences impose the necessity during endodontic treatment of change in professional perception and clinical maneuvers to try to overcome them. The aim of this study was to evaluate the anatomic interference of root canal in endodontic instrumentation, considering for this: (1) the presence of critical instrumentation zone (CIZ), (2) the influence of flexion angles of files, (3) the identifying of anatomical points on the planning of anticurvature filing in molar teeth. Forty-five mandibular incisors were instrumented with rotatory files (Protaper). Thirty were analyzed before and after chemical mechanical preparation, for determining and quantifying the CIZ area, by means of digital periapical radiographs in two incidences (bucco-lingual and mesio-distal) and cross sections obtained by micro-computed tomographic (μCT). The other fifteen samples were analyzed before and after preparation to evaluate the influence of the files bending angle, also using two views radiographs (BL and MD) and μCT cross sections. The radiographs were analyzed using Image J software and microtomographys using μCT software. Two hundred digital periapical radiographs were used to evaluate the influence of the anatomy in the planning of anticurvature filing in mesiobuccal roots of maxillary molars and mesial of mandibular molars. In this moment, the analysis was performed using Excel 2007 and ImageJ software. The CIZ results showed differences in morphology and root canal area when compared with radiographs in BL incidence and MD incidence. The CIZ was verified after buccal and lingual walls instrumentation, in mesio-distal radiographs and in cross sections. In respect of flexion angles of files, it was observed a decrease after instrumentation in both radiograph views. While in the cross-sections were observed at BL way deviation of file in the original canal path between 23.08 to 100% of cases and at MD way only in 7.69%. The highest values of dentin removal the root canal wall were observed in the MD direction of the tooth. When anatomical points and their distances in the roots of maxillary molars with the lower were compared, there was statistical difference in most of them (p<0.001). However, in data collected after the anticurvature filing simulation, statistical difference was only found in the remaining dentin of the root safety zone (p<0.001). The Straight Access filing showed higher values of dentin removed in the crown and in the root. Considering the results, it was concluded that the irregularities of the root canal and the force vectors generated by flexion angles interfere with the action of files during preparation; causing file decentralization and permanence of unprepared areas. From these results it was concluded that to do an efficient anticurvature filing without unnecessary and excessive removal of dentin, it s necessary knowledge and radiographic localization of anatomical points advocated in the present study.Fundação de Amparo a Pesquisa do Estado de Minas GeraisDoutor em OdontologiaAs interferências da anatomia do canal radicular impõem a necessidade durante o tratamento endodôntico de mudança na percepção do profissional e de manobras clínicas para tentar superá-las. O objetivo do presente estudo foi avaliar as interferências anatômicas do canal radicular na instrumentação endodôntica, considerando para isso: (1) a presença da zona crítica de instrumentação (ZCI); (2) a influência dos ângulos de flexão da lima; (3) a determinação dos pontos anatômicos no planejamento do preparo anticurvatura dos molares. Quarenta e cinco incisivos inferiores foram instrumentados com limas rotatórias (Protaper). Trinta foram analisados antes e após o preparo químico mecânico, para constatação e quantificação da área da ZCI, por meio de radiografias periapicais digitais em duas incidências (vestíbulo-lingual e mésiodistal) e de secções transversais obtidas por meio de microtomografia computadorizada (μTC). As outras quinze amostras foram analisadas antes e após o preparo para avaliar a influência do ângulo de flexão das limas, utilizando também radiografias em duas incidências (VL e MD) e secções transversais de μTC. As radiografias foram analisadas utilizando o software ImageJ e as microtomografias com o software do próprio aparelho de μTC. Duzentas radiografias periapicais digitais foram utilizadas para avaliação da influência da anatomia no planejamento do preparo anticurvatura nas raízes mésio-vestibular de molares superiores e nas mesiais de molares inferiores. Nesta etapa, a análise foi realizada por meio dos softwares Excel2007 e ImageJ. Os resultados referentes a ZCI apresentaram diferença na morfologia e área do canal radicular quando comparadas as radiografias na incidência VL com a MD. A ZCI foi constatada após a instrumentação nas paredes vestibular e lingual, nas radiografias mésiodistal e nas secções transversais. Com relação aos ângulos de flexão da lima observou-se diminuição após a instrumentação nas duas incidências radiográficas. Nas secções transversais foram observados no sentido VL, desvio da lima dentro do trajeto do canal original entre 23,08 a 100% dos casos e no sentido MD em somente 7,69%. Os maiores valores de desgaste de dentina da parede do canal radicular foram observados no sentido MD do dente. Quando comparados os pontos anatômicos e suas distâncias nas raízes dos molares superiores com as dos inferiores, houve diferença estatística na maioria deles (p<0,001). Entretanto, nos dados coletados após a simulação do desgaste anticurvatura, somente foi encontrada diferença estatística no remanescente de dentina da zona de segurança da raiz (p<0,001). O desgaste Acesso Reto apresentou os maiores valores de desgaste de dentina radicular e coronária. Diante dos resultados, concluiu-se que a irregularidade do canal radicular e os vetores de força gerados pelos ângulos de flexão interferem na ação das limas durante o preparo; causando descentralização do instrumento e permanência de áreas não instrumentadas. Além disso, para execução de um desgaste anticurvatura eficiente, mas sem remoção desnecessária e excessiva de dentina, faz-se necessário o conhecimento e localização radiográfica dos pontos anatômicos preconizados no presente estudo

Avaliação da influência do remanescente de hidróxido de cálcio na infiltração marginal de dentes tratados endodonticamente

The presence of calcium hydroxide intracanal medicament residual even after its clinical removal, regardless of the technique or material used, is a fact proven by the literature. The aim of this study was to evaluate the influence of remaining Ca(OH)2 on marginal leakage of endodontic treated teeth. Two levels of leakage were considered: through apical foramen and root s medium third and the dye diffusion was quantified in length and depth. Seventy-two single-rooted bovine teeth after root canal biomechanical preparation were divided into two groups GI and GII (n=36). Specimens of the GI group, after canal preparation were immediately obturated and the GII samples were filled with Ca(OH)2 associated with saline solution. After seven days the medication was removed and the canals were filled likewise GI group by lateral condensation technique with a zinc oxide-eugenol sealer. Half of the specimens of GI and GII (n = 18) had their apical third and part of the medium third removed and alongside with the full-length roots , were immersed in India ink for 72 hours. For the evaluation of dye leakage the experimental specimens were cross-sectioned, photographed and had the infiltration perimeter measured by means of the Image Tool 3.00 software. After the analysis of length and depth infiltration, the lowest dye penetration values were found in Ca(OH)2 medicament receiving groups, independently of the leakage level. Therefore, we concluded that the use of Ca(OH)2 intracanal medicament significantly decrease the dye leakage through both apical foramen and root s medium third regarding length and depth.Fundação de Amparo a Pesquisa do Estado de Minas GeraisMestre em OdontologiaA permanência de resíduos da medicação intracanal de hidróxido de cálcio mesmo após sua remoção clínica, independente da técnica ou material usado, é um fato comprovado pela literatura. O objetivo da presente pesquisa foi avaliar a influência do resíduo de Ca(OH)2 na infiltração marginal de dentes tratados endodonticamente. Foram considerados dois níveis de infiltração, via forame apical e via terço médio radicular, sendo que a difusão do corante foi quantificada em extensão e profundidade. Setenta e dois dentes bovinos unirradiculares após o preparo biomecânico foram divididos em dois grupos (GI e GII) de 36 raízes cada. As amostras do grupo GI, após o preparo do canal foram imediatamente obturadas e as do grupo GII foram preenchidas com pasta de Ca(OH)2 associada ao soro fisiológico. Decorridos sete dias a medicação foi removida e os canais foram obturados como o grupo GI pela técnica de condensação lateral com cimento à base de óxido de zinco e eugenol. Em metade das amostras do GI e GII (n=18) o terço apical e parte do terço médio foi removido e juntamente com as raízes que ficaram com o comprimento completo, foram imersas em corante tinta nanquim por 72 horas. Para avaliação da infiltração do corante foram realizadas secções transversais das amostras experimentais, as quais foram fotografadas e tiveram o perímetro infiltrado quantificado com o auxílio do software Image Tool 3.00. Após a análise dos valores relativos à extensão e à profundidade de infiltração, os menores valores de infiltração do corante foram encontrados nos grupos que receberam o Ca(OH)2, independente do nível de infiltração. Diante dos resultados, concluiu-se que o uso da medicação intracanal de Ca(OH)2 diminuiu significativamente a infiltração marginal do corante tanto via forame apical quanto via terço médio radicular em relação à extensão e profundidade

Effects of bleaching agents and adhesive systems in dental pulp: a literature review

The dental pulp may be exposed to several irritants that are potentially noxious to the health and functions of this tissue. Each type of irritant or injury has different effects on the pulp, which are generally characterized by acute inflammation, chronic inflammation or necrosis. Common examples of irritants are dental caries, cavity preparation procedures, traumatic injuries, and chemical substances like bleaching agents and adhesive systems. The present study aimed to review the current knowledge about the effect of bleaching agents and adhesive systems in the human dental pulp. The review covered literature from 2004 to 2009, and only relevant manuscripts were included. Hand search of the references completed the review. Based on literature review, it may be concluded that all dental procedures associated with bleaching agents or adhesive systems involve risks to cause pulp damage. However, these risks can be minimized if the causal factors were known and avoided

A extensão em ação nos atendimentos e tratamentos endodônticos e restauradores em dentes molares na Faculdade de Odontologia da UFU para a comunidade de Uberlândia, Minas Gerais

O projeto "Atendimento clínico de pacientes com necessidade de tratamento endodôntico e restaurador em dentes molares" foi criado em 2015, visando ampliar o atendimento e tratamento endodôntico e restaurador da comunidade de Uberlândia advinda do Pronto Socorro Odontológico e clínicas de graduação da Faculdade de Odontologia da Universidade Federal de Uberlândia (FOUFU). Além do caráter assistencial prestado à comunidade por meio de atendimento clínico, o projeto contou com atividades de capacitação para acadêmicos permitindo que vivenciassem um campo de atuação com mais habilidade. Este trabalho apresenta as atividades realizadas nos dois primeiros anos de atuação do projeto. Os atendimentos foram realizados semanalmente no Hospital Odontológico da FOUFU por estudantes da graduação, em pacientes previamente triados. Nos dois primeiros anos do projeto, 198 pacientes foram triados, 151 encaminhados para outras clínicas da FOUFU, 47 tiveram os tratamentos concluídos e 24 acadêmicos foram capacitados. Conclui-se que o projeto conseguiu realizar os seus objetivos com sucesso ao: a) atender e encaminhar os pacientes da comunidade de Uberlândia que ainda estariam na fila de espera para tratamento ou que teriam perdido o dente caso o projeto não existisse; b) aumentar a habilidade clínica dos estudantes participantes nos tratamentos de dentes molares

Effects of bleaching agents and adhesive systems in dental pulp: a literature review

tal pulp may be exposed to several irritants that are potentially noxious to the health and functions of this tissue. Each type of irritant or injury has different effects on the pulp, which are generally characterized by acute inflammation, chronic inflammation or necrosis. Common examples of irritants are dental caries, cavity preparation procedures, traumatic injuries, and chemical substances like bleaching agents and adhesive systems. The present study aimed to review the current knowledge about the effect of bleaching agents and adhesive systems in the human dental pulp. The review covered literature from 2004 to 2009, and only relevant manuscripts were included. Hand search of the references completed the review. Based on literature review, it may be concluded that all dental procedures associated with bleaching agents or adhesive systems involve risks to cause pulp damage. However, these risks can be minimized if the causal factors were known and avoided

Influence of calcium hydroxide on marginal leakage of endodontically treated teeth

Aim: To evaluate the influence of residual calcium hydroxide (CH) intracanal medication considering two dye leakage locations (apical foramen and middle root canal third) by quantifying the diffusion of India ink in length and depth. Methods: After biomechanical preparation, 72 single-rooted bovine teeth were divided into two groups in which half was filled with a CH and saline paste. After 7 days, the medication was removed and the canals in both groups were filled. Half of the samples had the apical third and part of middle third removed for infiltration of India ink at the middle third (MTI), while the rest were infiltrated at the apical foramen (AI). The following experimental groups were formed (n = 18 each): A1 - CH-medicated + AI, A2 - CH-medicated + MTI, B1 - non-medicated + AI, B2 - non-medicated + MTI. For evaluation of dye leakage, the experimental specimens were cross-sectioned, photographed and had the infiltration perimeter measured using the Image Tool 3.00 software. The Mann-Whitney U-test was used for statistical analysis (p <0.05). Results: The lowest values of dye penetration in length and depth were found in the groups receiving intracanal medication (A1 and A2). Conclusions: Lower dye penetration in length and depth at the two different locations was observed in the canals with residual CH intracanal medication

Influence of calcium hydroxide on marginal leakage of endodontically treated teeth

evaluate the influence of residual calcium hydroxide (CH) intracanal medication considering two dye leakage locations (apical foramen and middle root canal third) by quantifying the diffusion of India ink in length and depth. Methods: After biomechanical preparation, 72 single-rooted bovine teeth were divided into two groups in which half was filled with a CH and saline paste. After 7 days, the medication was removed and the canals in both groups were filled. Half of the samples had the apical third and part of middle third removed for infiltration of India ink at the middle third (MTI), while the rest were infiltrated at the apical foramen (AI). The following experimental groups were formed (n = 18 each): A1 CH-medicated + AI, A2 CH-medicated + MTI, B1 non-medicated + AI, B2 non-medicated + MTI. For evaluation of dye leakage, the experimental specimens were cross-sectioned, photographed and had the infiltration perimeter measured using the Image Tool 3.00 software. The Mann-Whitney U-test was used for statistical analysis (p<0.05). Results: The lowest values of dye penetration in length and depth were found in the groups receiving intracanal medication (A1 and A2). Conclusions: Lower dye penetration in length and depth at the two different locations was observed in the canals with residual CH intracanal medication

Influence of flexion angle of files on the decentralization of oval canals during instrumentation

The aim of this study was to evaluate the influence of the flexion angle of files on the decentralization of root canals during instrumentation. Fifteen lower incisors were instrumented with Protaper Universal files and radiographed in two directions (mesiodistal and buccolingual) before and after instrumentation with a #15 K-file in position for evaluating the flexion angle of files. The specimens were also scanned before and after instrumentation using micro-computed tomography to obtain the canal area and the distance from the center position of the file to the canal walls. Sections located 1.0 mm (end of the canal), 3.0 mm (apical third), 9.0 mm (middle third), and 15.0 mm (cervical third) from the apex were verified. After instrumentation, the flexion angles of files decreased by an average of 0.76º in the buccolingual direction and 1.92º in the mesiodistal direction (p < 0.001); the canal area increased by an average of 0.58, 0.37, 0.23 and 0.13 mm2 from the cervical to the end of the root canal (p < 0.001). Non-instrumented areas were observed on the buccal and lingual walls, and effective action of files was determined on the mesial and distal walls. The sections from the end of the canal showed canal deviation toward the lingual wall, whereas the other sections showed deviation toward the buccal wall. The flexion angles of files influence the final shape of the root canal, resulting in file decentralization along the pathway of the canal

Use of bioceramics in conventional endodontic treatment associated with endodontic surgery of teeth with extensive periapical lesion: case report

Pesquisa sem auxílio de agências de fomentoTrabalho de Conclusão de Curso (Graduação)Este estudo relatou o caso clínico de paciente do sexo masculino, 56 anos, com extensas lesões periapicais associadas aos dentes 12, 21 e 22, sugestivas de periododontite apical crônica ao exame radiográfico e rompimento de corticais ao exame tomográfico. Foi realizada uma abordagem endodôntica convencional e de retratamento, associadas a cirurgia parendodôntica utilizando materiais biocerâmicos, com 27 meses de acompanhamento. Os biocerâmicos utilizados foram: Bio-C Temp, Bio-C Sealer e MTA Repair HP. Na proservação, foi observada ausência de sintomatologia, formação óssea ao redor dos dentes 12 e 22 e diminuição do tamanho da lesão do 21. Diante do diagnóstico histopatológico de lesões císticas de origem odontogênica, ficou constatado que a cirurgia parendodôntica era realmente necessária como forma de complementação ao tratamento convencional. Quanto ao uso dos biocerâmicos, estes provavelmente ajudaram no processo de cicatrização óssea, viabilizando ainda mais a manutenção dos elementos dentários