Fatores que favorecem a obturação tridimensional e hermética do sistema de canais radiculares / Factors favoring the three-dimensional hermetic obturation of the root canal system

Objetivo: o presente estudo tem por objetivo demonstrar a possibilidade e a importância da obturação dos diferentes tipos de canais acessórios nos variados grupos dentários. Métodos: foram selecionados 11 casos clínicos em que o conhecimento da anatomia interna do sistema de canais radiculares, associado à boa utilização da técnica de preparo Crown-Down — com o uso de irrigação de hipoclorito de sódio a 1% e solução de EDTA trissódico a 17%, para uma eficiente limpeza e remoção da smear layer —, possibilitou o escoamento dos diferentes tipos de cimentos obturadores. Resultados: os cimentos Endométhasone, Sealapex e o cimento obturador de óxido de zinco e Eugenol propiciaram uma eficiente obturação do sistema de canais radiculares, com o auxílio da técnica obturadora híbrida de Tagger, na execução de um tratamento endodôntico de qualidade. Conclusão: pode-se concluir que, com a conciliação dos conhecimentos de anatomia, técnicas e substâncias, é possível obter resultados extremamente satisfatórios na obturação tridimensional e hermética do sistema de canais radiculares, resultando, assim, no sucesso do tratamento endodôntico

Avaliação radiográfica do sucesso e da qualidade do tratamento endodôntico em uma população brasileira

Objetivo: esta investigação tem como objetivo avaliar a prevalência de periodontite apical detectada na radiografia periapical e a relação entre a doença e a qualidade da obturação de canais radiculares realizada por estudantes de graduação. Métodos: foi investigada uma amostra aleatória de 131 prontuários de pacientes que haviam recebido tratamento do canal radicular na Faculdade de Odontologia de Araçatuba, Universidade Estadual Paulista. Realizou-se anamnese, radiografias e exame clínico quanto à sintomatologia dolorosa, presença e qualidade da restauração, bolsa periodontal, mobilidade dentária e trauma oclusal. Resultados:a porcentagem de sucesso obtido com o tratamento realizado pelos estudantes de graduação foi de 87,7%.Quando o tratamento foi adequado (43 casos), o percentual de sucesso foi de 90,69% (39 casos), enquanto para os tratamentos inadequados (14 casos), o percentual de sucesso foi de 78,57% (11 casos), sem diferença estatisticamente significativa(p>0,05). Não foi observada diferença estatisticamente significativa na taxa de sucesso relacionada ao sexo(p>0,05). A condição pulpar também não interferiu na taxa de sucesso (p>0,05). Conclusão: concluiu-se que o tratamento endodôntico foi satisfatório e alcançou uma taxa de sucesso adequada, em torno de 90% dos casos

Tissue reaction to Endométhasone sealer in root canal fillings short of or beyond the apical foramen.

OBJECTIVE: This study evaluated the response of periapical tissues to the endodontic sealer Endométhasone in root canal fillings short of or beyond the apical foramen. MATERIAL AND METHODS: Twenty root canals of premolars and incisors of 2 mongrel dogs were used. After coronal access and pulp extirpation, the canals were instrumented up to a size 55 K-file and the apical cemental barrier was penetrated with a size 15 K-file to obtain a main apical foramen, which was widened to a size 25 K-file. The canals were irrigated with saline at each change of file. The root canals were obturated either short of or beyond the apical foramen by the lateral condensation of gutta-percha and Endométhasone, originating 2 experimental groups: G1: Endométhasone/short of the apical foramen; G2: Endométhasone/beyond the apical foramen. The animals were killed by anesthetic overdose 90 days after endodontic treatment. The individual roots were obtained and serial histological sections were prepared for histomorphological analysis (H&E and Brown & Brenn techniques) under light microscopy. The following parameters were examined: closure of the apical foramen of the main root canal and apical opening of accessory canals, apical cementum resorption, intensity of the inflammatory infiltrate, presence of giant cells and thickness and organization of the apical periodontal ligament. Each parameter was scored 1 to 4, 1 being the best result and 4 the worst. Data were analyzed statistically by the Wilcoxon nonparametric tests (p=0.05). RESULTS: Comparing the 2 groups, the best result (p<0.05) was obtained with root canal filling with Endométhasone short of the apical foramen but a chronic inflammatory infiltrate was present in all specimens. CONCLUSIONS: Limiting the filling material to the root canal space apically is important to determine the best treatment outcome when Endométhasone is used as sealer.

Tissue reaction to Endométhasone sealer in root canal fillings short of or beyond the apical foramen

OBJECTIVE: This study evaluated the response of periapical tissues to the endodontic sealer Endométhasone in root canal fillings short of or beyond the apical foramen. MATERIAL AND METHODS: Twenty root canals of premolars and incisors of 2 mongrel dogs were used. After coronal access and pulp extirpation, the canals were instrumented up to a size 55 K-file and the apical cemental barrier was penetrated with a size 15 K-file to obtain a main apical foramen, which was widened to a size 25 K-file. The canals were irrigated with saline at each change of file. The root canals were obturated either short of or beyond the apical foramen by the lateral condensation of gutta-percha and Endométhasone, originating 2 experimental groups: G1: Endométhasone/short of the apical foramen; G2: Endométhasone/beyond the apical foramen. The animals were killed by anesthetic overdose 90 days after endodontic treatment. The individual roots were obtained and serial histological sections were prepared for histomorphological analysis (H&E and Brown & Brenn techniques) under light microscopy. The following parameters were examined: closure of the apical foramen of the main root canal and apical opening of accessory canals, apical cementum resorption, intensity of the inflammatory infiltrate, presence of giant cells and thickness and organization of the apical periodontal ligament. Each parameter was scored 1 to 4, 1 being the best result and 4 the worst. Data were analyzed statistically by the Wilcoxon nonparametric tests (p=0.05). RESULTS: Comparing the 2 groups, the best result (p<0.05) was obtained with root canal filling with Endométhasone short of the apical foramen but a chronic inflammatory infiltrate was present in all specimens. CONCLUSIONS: Limiting the filling material to the root canal space apically is important to determine the best treatment outcome when Endométhasone is used as sealer.

Influência do hipoclorito de sódio no processo de reparo de dentes de cães tratados em sessão única

Introdução: a eliminação de bactérias dos canais radiculares é essencial no tratamento endodôntico de dentes com polpas necrosadas, desde que bactérias não só causam,mas também mantêm, as lesões periapicais. Objetivo:analisar in vivo a influência de soluções irrigantes (NaOCl 1%, NaOCl 2,5%, solução salina estéril 0,9%) no tratamento de dentes de cães com lesão periapical crônica em sessão única. Métodos: quarenta canais radiculares de três cães da raça Beagle permaneceram expostos à cavidade bucal para permitir a contaminação e a formação de lesões periapicais crônicas. Em seguida, os canais radiculares foram preparados biomecanicamente. Durante a instrumentação, três soluções irrigantes foram utilizadas: G1 – NaOCl 2,5%; G2 – NaOCl 1%; G3 – solução salina estéril 0,9%. O grupo controle (G4) não recebeu tratamento nem selamento coronário. Os canais radiculares foram obturados com cones de guta-percha e Sealapex. As aberturas coronárias foram seladas com IRM e amálgama. Após 6 meses, os animais foram sacrificado se blocos de tecido processados histologicamente para serem corados com hematoxilina e eosina, ou Brown eBrenn. Resultados: não houve diferença histológica significativa entre a utilização de hipoclorito de sódio a 1%ou 2,5% (p>0,05), mas houve entre eles e a solução salina estéril a 0,9% (p<0,05). Conclusão: concluiu-se que o uso de soluções irrigantes com potencial antibacteriano (hipoclorito de sódio a 1% e 2,5%) proveu condições mais favoráveis ao processo de reparo

Avaliação do curativo de hidróxido de cálcio para a prevenção da infiltração coronária por um período curto

Objetivo: o objetivo desse estudo in vivo foi avaliar a influência da infiltração coronária no reparo apical de dentes de cães que receberam curativo de demora com hidróxido de cálcio e foram mantidos, ou não, em contato com o meio bucal. Métodos: após o preparo biomecânico e preenchimento com pasta de hidróxido de cálcio, 26 canais foram divididos aleatoriamente em dois grupos experimentais (Grupo 1 = selamento coronário com material restaurador temporário; Grupo 2 = não selados). Os animais foram sacrificados após 7 dias e os espécimes foram preparados para análise histológica.Resultados: em ambos os grupos, os resultados foram semelhantes, células inflamatórias não estavam presentes no tecido apical ou no cemento. Além disso, observou-se necrose na superfície do terço coronário do coto pulpar em contato com o hidróxido de cálcio, e microrganismos foram observados apenas em contato com resíduos que estavam presentes na câmara pulpar dos espécimes sem selamento, mas não no canal radicular. Conclusão: concluiu-se que o hidróxido de cálcio utilizado como curativo impediu a contaminação do canal radicular e manteve seu mecanismo de ação nos tecidos apicais, mesmo sem selamento coronário, por um período de 7 dias

Influence of apical foramen widening and sealer on the healing of chronic periapical lesions induced in dogs' teeth.

OBJECTIVE: The aim of this study was to evaluate the influence of apical foramen widening on the healing of chronic periapical lesions in dogs' teeth after root canal filling with Sealer 26 or Endomethasone. STUDY DESIGN: Forty root canals of dogs' teeth were used. After pulp extirpation, the canals were exposed to the oral cavity for 180 days for induction of periapical lesions, and then instrumented up to a size 55 K-file at the apical cemental barrier. In 20 roots, the cemental canal was penetrated and widened up to a size 25 K-file; in the other 20 roots, the cemental canal was preserved (no apical foramen widening). All canals received a calcium hydroxide intracanal dressing for 21 days and were filled with gutta-percha and 1 of the 2 sealers: group 1: Sealer 26/apical foramen widening; group 2: Sealer 26/no apical foramen widening; group 3: Endomethasone/apical foramen widening; group 4: Endomethasone/no apical foramen widening. The animals were killed after 180 days, and serial histologic sections from the roots were prepared for histomorphologic analysis. Scores were assigned according to preestablished histomorphologic parameters and analyzed statistically by Kruskal-Wallis and Mann-Whitney U tests. RESULTS: Regarding new cementum formation, repair of cementum and bone resorption areas, presence of microorganisms, inflammatory cell infiltrate and periodontal ligament conditions, significantly better periapical healing was obtained when foramen widening was done and Sealer 26 was used. CONCLUSION: Apical foramen widening and calcium hydroxide-containing sealer were more favorable to the healing of chronic periapical lesions.

Tissue reaction of the EndoREZ in root canal fillings short of or beyond an apical foramenlike communication.

This study evaluated the response of periapical tissues to the endodontic sealer EndoREZ in root canal fillings short of or beyond the apical foramenlike communication. Twenty root canals of premolars and incisors of 2 mongrel dogs were used. After coronal access and pulp extirpation, the canals were instrumented up to a size 55 K-file and the apical cemental barrier was penetrated with a size 15 K-file to create an apical foramenlike communication, which was widened to a size 25 K-file. The canals were irrigated with saline at each change of file. The root canals were obturated either short of or beyond the apical foramenlike opening by the lateral condensation of gutta-percha and EndoREZ, originating 2 experimental groups: G1, EndoREZ/short of the apical foramenlike opening, and G2, EndoREZ/beyond the apical foramenlike opening. The animals were killed by anesthetic overdose 90 days after endodontic treatment. The individual roots were obtained and serial histological sections were prepared for histomorphological analysis (H&E and Brown and Brenn techniques) under light microscopy. The following parameters were examined: closure of the apical foramenlike communication and apical opening of accessory canals, apical cementum resorptions, intensity of the inflammatory infiltrate, presence of giant cells, and thickness and organization of the apical periodontal ligament. Each parameter was scored 1 to 4, 1 being the best result and 4 the worst. Data were analyzed statistically by the Wilcoxon nonparametric tests (P = .05). Comparing the 2 groups, the best result (P = .05) was obtained with root canal filling with EndoREZ short of the apical foramenlike opening. In conclusion, limiting the filling material to the root canal space apically was important to determine the best treatment outcome when EndoREZ was used as the sealer.

Effect of calcium hydroxide-based materials on periapical tissue healing and orthodontic root resorption of endodontically treated teeth in dogs.

This study evaluated periapical tissue healing and orthodontic root resorption of endodontically treated teeth sealed with calcium hydroxide in dogs. The sample consisted of three contralateral pairs of maxillary incisors and two contralateral pairs of mandibular incisors in each of two dogs using a split mouth design. After biomechanical preparation of the teeth in the first group (n = 10), a Ca(OH)(2) dressing was placed for 14 days before root canal filling with Ca(OH)(2)-based sealer (Sealapex) and gutta-percha points. In the second group (n = 10), root canals were obturated immediately after the mechanical preparation with gutta-percha points and zinc oxide and eugenol (ZOE)-based sealer (Endofill). After completion of endodontic treatment, the teeth were moved with an orthodontic appliance with a calibrated force of 200 g, reactivated every 21 days. After 105 days, the animals were killed and the teeth were removed upon completion of active treatment, without a period of recovery, and prepared for histomorphological analysis. All sections of each tooth were graded subjectively on a scale from one to four to obtain the average of the 16 histomorphological parameters analysed. Evaluation of the differences between the two treatment protocols was made with Mann-Whitney U-test. It was observed that the teeth treated with Ca(OH)(2)-based materials provided better outcomes (P = 5%), with complete repair of all root resorption areas, high rate of biological closure of the main canal and apical accessory canals by newly formed cementum, less intense and extensive chronic inflammatory infiltrate, and better organization of the periodontal ligament. Under the tested conditions, Ca(OH)(2)-based materials had a favourable action on periapical tissue healing and repair of orthodontic root resorption in endodontically treated dogs' teeth.

Tratamento endodôntico de dens invaginatus / Endodontic treatment of dens invaginatus

O presente relato descreve o tratamento endodôntico não-cirúrgico de um incisivo lateral superior direito portador da malformação conhecida como dens invaginatus, com lesão periapical e ápice incompletamente formado. O tratamento realizado com medicação intracanal prolongada com pasta de hidróxido de cálcio/iodofórmio e propilenoglicol, e obturação definitiva do canal radicular com cimento Sealapex conduziu ao sucesso clínico, representado pelo reparo da lesão periapical e apicificação.

This case report describes a nonsurgical endodontic treatment of dens invaginatus in a maxillary right lateral incisor with periradicular lesion and incompletely formed apex. The treatment realized with a long-term intracanal dressing with calcium hydroxide paste with iodoform and propylene glicol and definitive filling of the root canal with Sealapex sealer, leaded to the clinical success, represented by the periradicular lesion healing and apicification.

A importância da restauração definitiva da coroa dentária pós-tratamento endodôntico / The importance of the definitive restoration of the dental crown after endodontic therapy

Assim como a infiltração marginal apical, a infiltração marginal coronária também vem sendo salientada e destacada com a publicação de numerosos trabalhos na literatura mais recente. Porém, houve um alerta para o assunto desde o século passado, quando se verificou que os materiais restauradores definitivos ou temporários têm as suas limitações. O presente relato aborda o problema da infiltração coronária em dentes tratados endodonticamente, decorrente de uma restauração definitiva inadequada. Aponta, ainda, para a necessidade de um tratamento endodôntico que vede hermeticamente todo o sistema de canais radiculares, bem como a durabilidade e eficiência dos materiais restauradores provisórios e definitivos. Aborda, por fim, outro fator complicador, quando o paciente não procura o profissional para completar o tratamento restaurador da coroa dentária.

As well as apicalleakage, coronary leakage have also recently acquired its due importance. However, such theme has been reported since last century, and it is well known that definitive or temporary restoring materiaIs have their limitations. This paper analyses this controversial subject, coronary leakage in endodontically treated teeth, as a result or not of definitive sealing. It also points out to the necessity of an endodontic approach that can hermetically seal all the root canal system, as well as to the durability and efficiency ofthe temporary and definitive restoring material. Itfinally approaches a complicatingfactor, thefact that the patient do not seekfor professional help to comply with the complete restoration of dental crown.

Evaluation of mineral trioxide aggregate and calcium hydroxide cement as pulp-capping agents in human teeth.

This study evaluated the histomorphologic response of human dental pulps capped with mineral trioxide aggregate (MTA) and Ca(OH)2 cement (CH). Pulp exposures were performed on the occlusal floor of 40 human permanent premolars. After that, the pulp was capped either with CH or MTA and restored with composite resin. After 30 and 60 days, teeth were extracted and processed for histologic exam and categorized in a histologic score system. The data were subjected to Kruskal-Wallis and Conover tests (alpha = .05). All groups performed well in terms of hard tissue bridge formation, inflammatory response, and other pulpal findings. However, a lower response of CH30 was observed for the dentin bridge formation, when compared with MTA30 and MTA60 groups. Although the pulp healing with calcium hydroxide was slower than that of MTA, both materials were successful for pulp capping in human teeth.

Reaction of the lateral periodontium of dogs' teeth to contaminated and noncontaminated perforations filled with mineral trioxide aggregate.

It has been shown that the mineral trioxide aggregate (MTA) used to seal lateral/furcal perforations stimulates the deposition of newly formed cementum. Nevertheless, when the site of the perforation is contaminated, the healing process might occur under less favorable conditions. This study evaluated the repair healing process of noncontaminated and contaminated lateral perforations filled with MTA and the effect of previously filling the contaminated perforations with a bactericidal agent. Thirty lateral root perforations were prepared in endodontically treated dog's teeth, thus forming 3 groups with 10 specimens each. In group 1 the perforations were immediately sealed with MTA. In group 2 the perforations were left open for 7 days and thereafter sealed with MTA. In group 3 the perforations were left open for 7 days, filled temporarily with a calcium hydroxide-based paste for 14 days, and then sealed with MTA. The animals were killed after 90 days, and the pieces were prepared for histomorphologic and histomicrobiologic evaluations. The statistical analysis showed that group 1 had significantly better repair than groups 2 (P < .05) and 3 (P < .05), which validates the superior results obtained when MTA was immediately used to seal root perforations. Groups 2 and 3 had statistically similar repair to each other (P > .05). There were a larger number of cases of complete or partial biologic seal in group 1 compared with the contaminated groups. It might be concluded that the lateral root perforations sealed with MTA after contamination presented worse repair than the noncontaminated, immediately sealed perforations. The temporary filling with a bactericidal agent (calcium hydroxide-based paste) did not improve the repair of perforations exposed to contamination, and the contaminated groups presented similar results to each other.

Mineral trioxide aggregate as a root canal filling material in reimplanted teeth. Microscopic analysis in monkeys.

This study analyzed mineral trioxide aggregate (MTA) as a root canal filling material for the immediate reimplantation of monkey teeth. Four adult capuchin monkeys Cebus apella were used, which had their maxillary and mandibular lateral incisors on both sides extracted and reimplanted after 15 min. During the extra-alveolar period, the teeth were kept in saline solution and after reimplantation retention was performed with a stainless steel wire and composite resin for 14 days. After 7 days, the reimplanted teeth were submitted to endodontic treatment with biomechanics up to file n. 30 and irrigation with a saturated solution of calcium hydroxide [Ca(OH)(2)], and then divided into two study groups: group I - root canal filled with a Ca(OH)(2) paste, and group II - root canal filled with MTA. Radiographic follow up was performed at 30, 60 and 90 days postoperatively, and after 180 days the animals were killed and specimens were processed for histomorphological analysis. The results revealed that most specimens of both groups presented organized periodontal ligament with no inflammation. The resorptions observed were surface resorptions and were repaired by cementum. Both MTA and Ca(OH)(2) were good root canal filling materials for immediately reimplanted teeth, providing good repair and also allowing biological sealing of some lateral canals. There was no significant difference between the study groups (alpha = 29.60%).

Influência do cimento endodôntico e do plug intracanal na infiltração coronária após obturação de canal radicular e preparo para pino / Influence of the endodontic sealer and the intracanal protection plug in the coronal leakage after root canal filling and postspace preparation

Ultimamente, a infiltração marginal coronária tem sido objetivo de muita preocupação. Demonstrou-se que, após preparo para pino, o emprego de um plug" protetor pode diminuir essa infiltração. Verificou-se também que não só o "plug" como o tipo de cimento obturador podem influenciar significantemente nos resultados. Assim, foi propósito deste trabalho obturar os canais de 90 dentes humanos unirradiculares, extraídos, com os cimentos AH Plus, Endofil ou Apexit, efetuar preparo para pino e proteger ou não os remanescentes das obturações com os cimentos temporários Tempfill ou Tempore. Após o tratamento, os dentes permaneceram imersos por 15 dias em saliva artificial, antes de serem colocados no azul de metileno a 2 por cento em ambiente com vácuo. A infiltração marginal coronária foi avaliada após partir os dentes ao meio no sentido longitudinal. Os resultados obtidos foram submetidos á análise de variância e ao teste de Tukey. Observou-se que os dados do cimento provisório Tempfill foram significantemente melhores que os do Tempore (p = 0,05). Além disso, demonstrou-se que os três cimentos obturadores de canais radiculares estudados podem ser ordenados do melhor selador para o pior da seguinte forma: a) Apexit, b) AH Plus, c) Endofill (p <0,05).

Influence of the type of vehicle and limit of obturation on apical and periapical tissue response in dogs' teeth after root canal filling with mineral trioxide aggregate.

The purpose of this study was to investigate the influence of the type of vehicle (distilled water or propyleneglycol) on the response of apical tissues of dogs' teeth after root canal filling with mineral trioxide aggregate (MTA) at two different limits. Forty roots of incisors and premolars of two adult dogs were used. After pulpectomy, the root canals were prepared biomechanically, and the roots had the apical cemental barrier penetrated with a #15 K-file and widened to a #25 K-file. The root canals were assigned to four groups according to the vehicle used for MTA (ProRoot-MTA; Tulsa Dental, Tulsa, OK) preparation and the limit of root canal filling: group 1, filling with MTA/distilled water to the limit of the cemental canal; group 2, overfilling with MTA/distilled water; group 3, filling with MTA/propyleneglycol to the limit of the cemental canal; and group 4, overfilling with MTA/propyleneglycol. The animals were killed by anesthetic overdose 90 days after endodontic treatment, and the anatomic pieces were prepared for histomorphological analysis. The sections were stained with hematoxylin and eosin and Brown and Brenn techniques. The results showed that MTA pastes prepared with either distilled water or propyleneglycol as vehicles had similar biological behavior (p > 0.05); root fillings placed at the cemental canal limit showed better results than the overfillings (p = 0.01), and MTA/propyleneglycol paste was more easily placed into the root canals than MTA/distilled water paste.

Periapical tissue healing after post space preparation with or without use of a protection plug and root canal exposure to the oral environment. Study in dogs.

The purpose of this study was to evaluate the influence of coronal leakage on the healing of dogs' periapical tissues after root canal filling, post space preparation and protection or not with a temporary sealer plug. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta-percha points and Endomethasone or CRCS sealers. After post space preparation, the remaining filling material was protected or not with a plug of temporary Coltosol sealer and exposed to the oral environment for 90 days. Thereafter, the animals were sacrificed and the specimens were removed and prepared for histomorphological and histobacteriological analysis. The findings revealed 35% of microbial leakage in the groups without plugs and 15% of leakage in the groups with plugs. Statistical analysis showed that the use of a Coltosol plug improved significantly the histomorphological results regardless of the type of root canal sealer (p=0.05) and that CRCS and Endomethasone sealers showed similar results (p>0.05).

Periapical tissue healing after post space preparation with or without use of a protection plug and root canal exposure to the oral environment: study in dogs

The purpose of this study was to evaluate the influence of coronal leakage on the healing of dogs' periapical tissues after root canal filling, post space preparation and protection or not with a temporary sealer plug. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta-percha points and Endomethasone or CRCS sealers. After post space preparation, the remaining filling material was protected or not with a plug of temporary Coltosol sealer and exposed to the oral environment for 90 days. Thereafter, the animals were sacrificed and the specimens were removed and prepared for histomorphological and histobacteriological analysis. The findings revealed 35 percent of microbial leakage in the groups without plugs and 15 percent of leakage in the groups with plugs. Statistical analysis showed that the use of a Coltosol plug improved significantly the histomorphological results regardless of the type of root canal sealer (p=0.05) and that CRCS and Endomethasone sealers showed similar results (p>0.05).

O propósito deste trabalho foi avaliar a influência da infiltração coronária no reparo dos tecidos periapicais após obturação dos canais radiculares, preparo para pino e proteção ou não de um "plug" de cimento temporário. Quarenta canais de dentes de cães foram instrumentados e obturados pela técnica da condensação lateral ativa com cones de guta-percha e os cimentos Endomethasone e CRCS. Após preparo para pino os remanescentes do material obturador foram protegidos ou não com um "plug" do cimento temporário Coltosol e expostos ao meio oral por 90 dias. Decorrido este período, os animais foram mortos e os espécimes foram removidos e preparados para análises histomorfológica e histobacteriológica. Foi observado 35 por cento de casos de infiltração bacteriana nos grupos sem "plug" e 15 por cento nos grupos com "plug". Concluiu-se estatisticamente que o "plug" de Coltosol foi eficiente no controle da infiltração coronária de microorganismos (p=0,05), e que os cimentos CRCS e Endomethasone apresentaram resultados semelhantes (p>0,05).

Avaliação da preparação do canal com sistema de rotação alternada e diferentes limas de aço inoxidável / Evaluation of root canal preparation with alternated rotary system and different stainless steel files

Introdução: O objetivo deste trabalho é avaliar o preparo de canais simulados em blocos de acrílico utilizando- se um sistema de rotação alternada e diferentes limas de aço inoxidável para instrumentação. Métodos: Quinze canais artificiais com 17mm de extensão e com curvaturas aproximadas de 33 graus contidos em blocos de resina foram utilizados para analisar o desgaste produzido nas paredes e a incidência de desvios apicais proporcionados pelas limas Flex-R, Flexofile e Dyna-Flex acionadas pelo sistema de rotação alternadaEndo-Gripper. As imagens iniciais dos canais foram capturadas no escâner, após preenchimento com tinta azul, seguindo-se o preparo cérvico-medial com brocas Gates-Glidden até a profundidade de 10mm. Os 7mm apicais dos canais foram, então, preparados com as limas em estudo, acionadas com rotação alternada, iniciando-se com o instrumento #15 e concluindo-se com o #35, com velocidade de 15.000 rpm. Concluído o preparo, os canais foram novamente preenchidos com a mesma tinta azul e as imagens novamente capturadas. Através do programa Imagelab 2.3, compararam-se os valores das mensurações inicial e final de cada espécime, os quais foram analisados estatisticamente através da análise de variância e Teste de Tuckey. Conclusão: Observou-se que a lima Flexofile proporcionou desgaste significativamente maior do que a Flex-R e Dyna-Flex, e entre estas não houve diferença significativa, e que os três tipos de instrumentos empregados não provocaram desvios apicais.

Introduction: The objective of this work is to evaluate the preparation of the canals simulated in acrylic blocks using different stainless steel files for instrumentation purposes. Methods: Fifteen artificial canals 17mm long and curved at 33º inside resin blocks were used to analyze wall wearing and deviation of the canals produced by Flex-R, Flexofile and Dyna-Flex files powered by Endo-Gripper as an alternate rotary system. The initial images were obtained by a scanner after the canals were filled with blue ink and prepared with Gates-Glidden burs until 10mm from the cervical portion of the canals. The remaining 7mm was prepared with files under alternate rotation. File#15 was the first to be used and #35 was the last, at15.000 rpm. After the preparation, the canals were filled with the same blue ink and the images were once more obtained. The initial and final measures were statistically compared. Conclusion: It was observed that the Flexfile produced a significantly wider wearing than Flex-R and Dyna-Flex, without statistical differences between them, and none of instruments tested caused apical deviation.

Association of calcium hydroxide and metronidazole in the treatment of dog's teeth with chronic periapical lesion

One of the primary objectives of endodontic treatment of teeth with pulp necrosis is the elimination of microorganisms from the root canal system, as effectively as possible, especially in cases with chronic periapical lesions. AIM: The purpose of this study was to analyze the response of the periapical tissue of dogs' teeth with chronic periapical lesions to endodontic treatment performed with utilization of metronidazole, calcium hydroxide, and an association of both as root canal dressings. METHODOLOGY: Forty root canals were submitted to pulpectomy and the root canals were kept exposed to the oral environment for 6 months. Then, they were submitted to biomechanical preparation and divided into 4 study groups with 10 specimens: group I - no root canal dressing; group II - calcium hydroxide; group III - metronidazole; group IV - calcium hydroxide associated to metronidazole. After 15 days, the root canals were filled with Fill Canal sealer. After 90 days, the animals were killed and the especimens processed for histological analysis. RESULTS: Calcium hydroxide dressing provided a significantly better outcome compared to other experimental groups (alpha = 0.01). Also, the results of the association of metronidazole and calcium hydroxide were similar to those observed for the metronidazole group. The worst results were obtained by the no root canal dressing group. CONCLUSION: The use of metronidazole alone or associated with Calcium hydroxide, did not improve periapical healing when compared to Calcium hydroxide dressing.

Um dos principais objetivos do tratamento endodôntico de dentes com polpa necrosada é a eliminação máxima possível dos microrganismos presentes no sistema de canal radicular, principalmente nos casos que apresentam lesões periapicais crônicas. OBJETIVO: O presente trabalho teve como objetivo analisar a resposta dos tecidos periapicais de dentes de cães com lesão periapical crônica ao tratamento endodôntico utilizando como curativo de demora o metronidazol, o hidróxido de cálcio e a associação das duas substâncias. METODOLOGIA: Foram empregados 44 canais radiculares de 2 cães adultos, portadores de lesão periapical crônica induzida experimentalmente. Após o preparo biomecânico os dentes foram divididos em quatro grupos experimentais de acordo com o curativo de demora empregado: Grupo I - controle - sem curativo de demora; Grupo II - hidróxido de cálcio; Grupo III - associação de hidróxido de cálcio e metronidazol e Grupo IV - metronidazol. Após 15 dias todos os canais foram obturados com cimento Fill Canal e passados 90 dias os animais foram sacrificados. RESULTADOS: Os dados obtidos evidenciaram que o hidróxido de cálcio apresentou resultado superior aos demais tratamentos, com diferença estatísticamente significante (alfa = 0.01) e o metronidazol resultado semelhante à associação do hidróxido de cálcio com o metronidazol. Os piores resultados foram obtidos pelo grupo sem curativo de demora. CONCLUSÃO: O uso de metronidazol ou da sua associação com hidróxido de cálcio, não proporcionou melhoras no reparo quando comparado ao curativo de hidróxido de cálcio.