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

Infiltração marginal apical após obturação de canais retos e curvos pela técnica da condensação lateral e do cone único: influência do tipo de cimento obturador empregado / Marginal leakage after filling of straight and curved root canals by the lateral condensation and single cone technique: influence of the type of sealer applied

O objetivo deste estudo foi avaliar in vitro o selamento marginal apical obtido com a obturação dos canais radiculares retos e curvos pela técnica da condensação lateral e do cone único os cimentos endodônticos Sealapex® e Endofill®. Foram empregadas 90 raízes de dentes humanos recém-extraídos, retas e curvas. A instrumentação do canal radicular foi realizada utilizando a técnica da condensação lateral e do cone único, sob abundante irrigação com solução de hipoclorito de sódio a 2,5%. Em seguida as raízes foram obturadas. As raízes obtidas, retas e curvas, foram distribuídas em número de 10 para cada grupo experimental e em número de 5 para o grupo controle positivo e 5 para o grupo controle negativo. As raízes foram submetidas ao teste de infiltração de corante com azul de metileno 2% por 48 horas, utilizando bomba a vácuo. As raízes foram partidas ao meio, longitudinalmente, e a avaliação da infiltração marginal foi realizada do ápice para coroa. Os resultados obtidos foram submetidos ao teste ANOVA e ao teste de Tukey. Os resultados mostraram que o Sealapex® apresentou menor infiltração, canais retos demonstraram melhores resultados que canais curvos e não houve diferença nos resultados entre as técnicas de obturação

The aim of this study was to evaluate in vitro the apical sealability obtained with a root canal filling straight and curved by the lateral condensation and single cone technique with Sealapex® and Endofill® sealers. Ninety freshly extracted root teeth were used, straight and curved. The instrumentation of the root canal was accomplished using the technique of lateral condensation and single cone, with abundant irrigation with solutions of 2.5% sodium hypochlorite. Then the roots were filled. The roots obtained, straight and curved, the roots were divided in groups of 10 specimens for each experimental group and 5 specimens for the positive control group and 5 for the negative control group. The roots were submitted to dye leakage with 2% methylene blue for 48 hours but using vacuum. The roots were cut longitudinally and the leakage was measured in a linear fashion from apex to crown. Data were analyzed by ANOVA and Tukey test. The results showed that the Sealapex® had lower leakage, straight canals showed better results than curved canals and there was no difference in results between the filling techniques

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.

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.

Evaluation of tissue response to periodontal dressings: histological study in tooth sockets of rats.

Although the use of periodontal dressings is currently limited, there are some indications for their use. Selection of any material that will have direct contact with live tissues, such as periodontal dressings, should be careful in order to allow surgical wound healing. The aim of this study was to evaluate the intensity of inflammatory response and bone formation in tooth sockets of rats after implantation of three periodontal dressings. After removal of the right maxillary incisors of 84 male rats, each tooth socket received implantation of a polyethylene tube, 63 of which were filled with non-eugenol periodontal dressing and the remaining 21 tubes remained empty (control group). Histological evaluation assessed the intensity of inflammatory response and presence and location of bone tissue formation at postoperative periods of 7, 14 and 28 days. Statistical analysis was performed by the Kruskal-Wallis test at 5% significance level. Regarding the inflammatory infiltrate, at 28 days, there was statistically significant difference between one of periodontal dressings and control group (p<0.05). Analysis of postoperative periods, showed that the control group presented statistically significant reduction in the inflammatory infiltrate comparing the 14- and 28-day periods (p<0.05). Regarding bone tissue formation, there was difference in control group between the 7- and 28-day periods (p<0.05). Within the experimental conditions, it may be concluded that no differences were found in the inflammatory response among the groups at 7 and 14 days and that Voco pac dressing induced a more intensive inflammatory reaction at 28 days.

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.

Evaluation of tissue response to periodontal dressings: histological study in tooth sockets of rats

Although the use of periodontal dressings is currently limited, there are some indications for their use. Selection of any material that will have direct contact with live tissues, such as periodontal dressings, should be careful in order to allow surgical wound healing. The aim of this study was to evaluate the intensity of inflammatory response and bone formation in tooth sockets of rats after implantation of three periodontal dressings. After removal of the right maxillary incisors of 84 male rats, each tooth socket received implantation of a polyethylene tube, 63 of which were filled with non-eugenol periodontal dressing and the remaining 21 tubes remained empty (control group). Histological evaluation assessed the intensity of inflammatory response and presence and location of bone tissue formation at postoperative periods of 7, 14 and 28 days. Statistical analysis was performed by the Kruskal-Wallis test at 5% significance level. Regarding the inflammatory infiltrate, at 28 days, there was statistically significant difference between one of periodontal dressings and control group (p<0.05). Analysis of postoperative periods, showed that the control group presented statistically significant reduction in the inflammatory infiltrate comparing the 14- and 28-day periods (p<0.05). Regarding bone tissue formation, there was difference in control group between the 7- and 28-day periods (p<0.05). Within the experimental conditions, it may be concluded that no differences were found in the inflammatory response among the groups at 7 and 14 days and that Voco pac™ dressing induced a more intensive inflammatory reaction at 28 days.

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.

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.

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).

Análise histomorfológica de dentes decíduos de cães com rizogênese incompleta, após biopulpectomia e obturação dos canais radiculares com hidróxido de cálcio em diferentes veículos / Histomorphological analysis of dogs' deciduous teeth with open apex, after biopulpectomy and root canal filling qith calcium hydroxide in dufferent vehicles

A dentição decídua é passível de ser acometida por traumatismos, lesões cariosas precoces ("cárie de mamadeira") ou outro tipo de injúria, que podem comprometer a vitalidade pulpar desses dentes, inclusive com rizogênese incompleta. A escassez de trabalho específico sobre o assunto, bem como a importância de solucionar adequadamente esse tipo de problema, em dentes decíduos com rizogênese incompleta, estimulam a realização de investigações sobre o assunto. Portanto, o objetivo deste estudo foi avaliar, histologicamente, a resposta dos tecidos apicais e periapicais de dentes decíduos de cães, com rizogênese incompleta, após biopulpectomia e obturação dos canais radiculares com hidróxido de cálcio em diferentes veículos. Assim, os canais radiculares de 80 dentes decíduos anteriores de 6 cães da mesma ninhada, com 50 dias de idade, e com rizogênese incompleta, foram empregados neste estudo. Após o preparo biomecânico, os canais radiculares foram obturados com os seguintes materiais: Grupo 1- pasta Vitapex (hidróxido de cálcio, iodofórmio e óleo de silicone), Grupo 2- hidróxido de cálcio acrescido de iodofórmio e soro fisiológico, Grupo 3- hidróxido de cálcio associado ao Lipiodol e, Grupo 4 - controle - dentes com canais preparados e não obturados. Trinta dias após o tratamento, os animais foram mortos e os espécimes preparados para análise histomorfológica. A análise estatística dos resultados permitiu que os materiais estudados fossem ordenados do melhor para o pior resultado da seguinte forma: a) hidróxido de cálcio acrescido de iodofórmio e soro fisiológico, b) pasta Vitapex (hidróxido de cálcio acrescido de iodofórmio e óleo de silicone), c) hidróxido de cálcio associado ao lipiodol, d) controle. Ocorreu diferença estatisticamente significante (p=0,05) entre os resultados do grupo do hidróxido de cálcio acrescido de iodofórmio e soro fisiológico com os do grupo hidróxido...

Histological analysis of the periapical tissues of dog deciduous teeth after root canal filling with diferent materials

O objetivo de encontrar um material ideal para obturar canais radiculares de dentes decíduos ainda não foi alcancado. Esse fato estimulou a realizacão de uma experimentacão para analisar histologicamente a reacão dos tecidos periapicais a 3 materiais obturadores de canal. Assim, oitenta canais radiculares de dentes decíduos anteriores de 6 cães, com 60 dias de idade, fora empregados neste estudo. Após o preparo biomecânico, os canais radiculares foram obturados com os seguintes materiais: pasta lentamente reabsorvível de Maisto, Sealer 26 com iodofórmio, pasta L&C (hidróxido de cálcio com óleo de oliva) e, como grupo controle, dentes cujos canais foram preparados biomecanicamente mas não obturados. Trinta dias após o tratamento os animais foram mortos e as pecas processados para análise histológica. Os resultados permitiram ordenar estatisticamente os materiais do melhor para o pior da seguinte maneira: a- Pasta de Maisto, b- Sealer 26 com iodofórmio, c- grupo controle, d- Pasta L&C. Foi observado diferenca significante (p=0,01) somente quando os resultados dos diferentes grupos foram comparados com o grupo da pasta L&C. Foi também observado que a pasta L&C não foi biologicamente compatível enquanto os outros materiais foram biocompatíveis, porém suas velocidades de reabsorcão não foram a mesma observada com as raízes dos dentes decíduos.

Influence of apical patency and filling material on healing process of dogs' teeth with vital pulp after root canal therapy.

The purpose of this study was to investigate the periapical healing process of dogs' teeth with or without apical patency and after root canal filling with two types of sealers. Forty roots of premolars and incisors were utilized. The root canals were over-instrumented and dressed with a corticosteroid-antibiotic solution for 7 days to obtain ingrowth of periapical connective tissue into the canals. After this period, the tissue was removed in half of the specimens (groups with patency) and preserved in the other half (groups without patency). Canals were filled by lateral condensation technique with gutta-percha points and either a calcium hydroxide-based sealer (Sealer Plus) or a Grossman's cement (Fill Canal). The animals were killed by anesthetic overdose 60 days after the endodontic treatment and anatomic pieces were obtained and prepared for histologic examination. Data were evaluated in a blind analysis on the basis of several histomorphologic parameters. The groups without patency had better results (p=0.01) than those in which the ingrown connective tissue was removed. Comparing the sealers, Sealer Plus had significantly better results (p=0.01) than Fill Canal. In conclusion, both the apical patency (presence or absence) and the type of root canal filling material influenced the periapical healing process in dogs' teeth with vital pulp after root canal treatment. The use of a calcium hydroxide-based sealer in teeth without apical patency yielded the best results among the experimental conditions proposed.

Influence of apical patency and filling material on healing process of dogs' teeth with vital pulp after root canal therapy

Foi propósito deste trabalho observar o processo de reparo de dentes de cães após obturação dos canais com dois cimentos diferentes, fazendo ou não a patência apical. Após uma sobreinstrumentação, os canais receberam um curativo de uma solução de corticosteróide-antibiótico por 7 dias, com o objetivo de obter invaginação de tecido conjuntivo para dentro dos canais. Após esse período, esse tecido foi totalmente removido em metade dos casos (grupos com patência apical) e preservados no restante dos casos (grupos sem patência apical). Os canais foram obturados pela técnica da condensação lateral empregando um cimento a base de hidróxido de cálcio (Sealer Plus) ou um cimento de Grossman (Fill Canal). Os animais foram sacrificados por overdose anestésica 60 dias após o tratamento endodôntico e as peças anatômicas foram obtidas e preparadas para análise histológica. Os dados obtidos foram analisados com base em diversos parâmetros histomorfológicos. Os resultados foram melhores nos grupos sem patência apical (p=0,01) do que nos grupos com patência. Dentre os cimentos estudados, os melhores resultados foram observados com o cimento Sealer Plus (p=0,01). Em conclusão, tanto a patência apical (presença ou ausência) quanto o tipo de material obturador de canal influíram no processo de reparo apical de dentes de cães com polpas vitais após tratamento endodôntico. O emprego de um cimento a base de hidróxido de cálcio em dentes sem patência apical promoveu os melhores resultados, dentre as condições experimentais propostas.