Novas tecnologias associadas ao retratamento endodôntico não cirúrgico

Introdução: O trabalho elaborado desenvolve o tema seguinte: Novas tecnologias associadas ao retratamento endodôntico não cirúrgico. Desde o início da medicina dentária que somos deparados com o insucesso nos tratamentos realizados, na endodôntia sendo um acontecimento regular na prática diária. Quando o tratamento Endodontico não cirúrgico não é eficaz na resolução de patologias pulpares e ocorre recidiva da patologia, é necessário a realização do retratamento endodôntico não cirúrgico. Uma vez que o retratamento endodôntico, respeita os mesmos princípios do tratamento Endodontico, sendo estes a desinfeção do sistema de canais radiculares, a sua instrumentação e obturação. Esta prática está indicada por vários motivos, anatómicos, microbiológicos, erros de instrumentação, erros de obturação e as próprias limitações dos materiais. Objetivos: Esta dissertação tem como objetivo analisar, e verificar as razões que levam a necessidade da realização de retratamentos endodônticos não cirúrgicos, aos métodos utilizados na realização de retratamentos comparando-os entre si. Tendo sido realizada uma revisão bibliográfica de modo a verificar: as causas de insucesso, limitações dos materiais, técnicas de obturação, agentes químicos e sistemas de instrumentação. Materiais e Métodos: Para a obtenção da informação necessária para a elaboração da presente dissertação, foi realizada uma pesquiza bibliográfica nas bases de dados da Pubmed, B-on, Scielo, Science Direct e no Google Académico. Através das seguintes palavras-chave: “Root canal treatment”, “Endodontic sucess”, “Endodontic retreatment”, “Endodontic Failure causes”, “Root canal retreatment materials”, “Endodontic retreatment metods”, “Chloroform”, “ProTaper, Reciproc”, “Haloten”, “Orange oil”, “Eucaliptol”, “Ultrassonic instrumentation”, “obturation material”, “root filling”. Conclusão: No trabalho realizado é possível concluir que o insucesso tem múltiplas causas, que hoje em dia existem novos métodos e técnicas que nos permitem a resolução das falhas nos tratamentos primários, sendo que estes novos métodos e técnicas se revelaram mais eficazes que os tradicionais, demonstrando uma maior probabilidade de eliminação dos fatores causais das reinfeções.

Remoção de instrumentos fraturados em Endodontia

A área da Endodontia está em constante progresso. Os materiais utilizados nos instrumentos Endodônticos, primordialmente, eram construídos com base em cordas de piano. Seguiu-se uma fase em que estes eram de aço de carbono, mas sofriam corrosão significativa devido ao cloro presente no hipoclorito de sódio, bem como aos processos de esterilização a vapor. Foi necessário evoluir novamente e foram introduzidos os instrumentos de aço inoxidável. Estes apresentavam alta resistência e dureza, mas algumas desvantagens devido à falta de flexibilidade. Atualmente, os instrumentos de NiTi proporcionam uma melhor flexibilidade e efeito de memória de forma. A fratura de instrumentos em Endodontia pode ocorrer por dois grandes fatores: a torção e a flexão por fadiga cíclica, podendo também ser a conjugação de ambos. Fatores anatômicos, como a curvatura e a largura do canal ou outros fatores como ciclos de esterilização, número de usos, etc., podem influenciar uma fratura mais precoce dos instrumentos. A incidência da fratura de instrumentos, embora seja pouco frequente, pode ser reduzida a um mínimo absoluto se os clínicos usarem as características de torque e de stress adequadas. Um bom conhecimento dos procedimentos clínicos, da anatomia, dos materiais e a utilização de instrumentos como o microscópio podem ajudar a prevenir ou a resolver a fratura dos instrumentos. No entanto, a melhor forma de prevenir a fratura é a sua prevenção. A desinfeção é o procedimento mais importante para o sucesso de um tratamento Endodôntico, portanto para que isto seja possível, é necessária uma boa conformação canalar. A presença de um instrumento no interior do canal pode comprometer a desinfecção, especialmente caso tenha ocorrido numa fase precoce da preparação canalar. Aquando da fratura de um instrumento, deve-se refletir sobre os procedimentos a seguir, podendo-se optar por várias abordagens, nomeadamente pela manutenção do instrumento no canal e obturação incorporando o fragmento, pela remoção do segmento através de diversas técnicas (ultrassons ou técnicas de microtubos, etc.), e ainda pela realização do bypass ou pela cirurgia Endodôntica. Em última instância pode ser realizada a extração do elemento dentário.

Factors associated with the technical quality of root canal fillings performed by undergraduate dental students in a Malaysian Dental School

Aim: A retrospective clinical audit was carried out on records of endodontic treatment performed by dental undergraduates. The audit was performed to evaluate the technical quality of root canal fillings performed by dental undergraduates and determine the associated factors. Methods: 140 records of patients who had received root canal treatment by dental undergraduates were evaluated through periapical radiographs by two examiners (κ =0.74). The root canal fillings had their quality evaluated according to extent, condensation and presence of procedural mishap. Possible factors associated with technical quality such as tooth type, canal curvature, student level and quality of record keeping were evaluated. Data were statistically analyzed using chi-square test (p<0.05). Results: Among the 140 root-filled teeth, acceptable extent, condensation and no-mishap were observed in 72.1%, 66.4% and 77.9% cases respectively. Overall, the technical quality of 68 (48.6%) root-filled teeth was considered acceptable. Overall, non-acceptable root canal fillings were significantly more likely to be observed in molars (69.2%), moderately and severely curved canals (71.4%) and junior students (61.5%). There was no association between acceptable root canal fillings and quality of record keeping. Conclusions: The technical quality of root canal fillings was acceptable in 48.6% cases and it was associated with tooth type, degree of canal curvature and student seniority.

Analysis of root canal organic tissue dissolution capacity according to the type of irrigation solution and agitation technique

Aim: To analyze the root canal organic tissue dissolution capacity promoted by irrigating solutions, with or without the use of different agitation techniques. Methods: Bovine pulp tissue fragments were initially weighed. The following irrigating solutions were tested: 2.5% sodium hypochlorite, 2% chlorhexidine digluconate solution, and distilled water. The irrigating protocols were: immersion, mechanical agitation with endodontic files, and ultrasonic or sonic systems (Endoactivactor® and Easy Clean®). At the end of the protocols, the pulps were weighed to determine their final weight. For comparison, the average percentage of tissue dissolution in relation to the groups was analyzed using the Kruskal-Wallis nonparametric test complemented by multiple comparisons test. The significance level was set at 5%. Results: Among the irrigation solutions, 2.5% sodium hypochlorite showed a higher dissolving power than 2% chlorhexidine digluconate and distilled water. Furthermore, ultrasonic and sonic systems were more effective irrigating protocols than immersion and mechanical agitation with endodontic files. Conclusions: The combination of sodium hypochlorite with an agitation system promotes a greater degree of tissue degradation.

Apical Leakage of Three Resin-Based Endodontic Sealers after 810-nm-Diode Laser Irradiation

Objective: To evaluate the influence of 810-nm-diode laser irradiation, applied before root canal filling, on apical sealing ability of three different resin-based sealers (AH Plus, EndoRez, and RealSeal). Background: Lasers have been widely used in endodontics. The dentin wall changes caused by laser irradiation could improve the sealing ability of endodontic cements. Methods: Sixty single-rooted human teeth were divided into six groups, according to the endodontic sealer used and previous 810-nm-diode laser irradiation. The protocol for laser irradiation was 2.5W in a continuous wave, in scanning mode, with four irradiations per tooth. After sample preparation, they were analyzed according to apical leakage with silver nitrate impregnation. Results: The RealSeal sealer achieved minimum leakage rates (1.24 mm), with significant differences at the 1% level (Tukey's test, p < 0.01) from AH Plus (1.84 mm) in nonirradiated groups. When the laser was used, there were also significant differences at the 5% level (p < 0.05) between irradiated groups (1.31 and 1.78 mm, respectively). Conclusion: The 810-nm-diode laser irradiation did not promote significant differences in apical leakage.

Physical Properties and Interfacial Adaptation of Three Epoxy Resin-based Sealers

Introduction: The aim of the study was to evaluate the radiopacity, solubility, flow, film thickness, setting time, and adaptation to the root canal walls of 3 epoxy resin based sealers: AH Plus, Acroseal, and Adseal. Methods: Physical tests were performed following American National Standards Institute/American Dental Association`s requirements. For interfacial adaptation analysis, 30 maxillary canines were shaped by using Pro Taper instruments. The specimens were divided into 3 groups (n = 10): group 1, AH Plus; group 2, Acroseal; and group 3, Adseal. The sealers were mixed with rhodamine B dye, and the canals were filled by using the lateral compaction technique. The percentage of gaps and voids area was calculated at 2, 4, and 6 mm levels from the apex. Statistical evaluation was performed by using analysis of variance for physical analysis and nonparametric Kruskal-Wallis and Dunn tests for interfacial adaptation (P<.05). Results: No statistical differences were found for adaptation, percentage of voids, solubility, flow, and film thickness among the sealers (P>.05). AH Plus was significantly more radiopaque (P<.05). For the setting time, there were statistical differences among all the studied sealers (P<.05). Conclusions: AH Plus, Acroseal, and Adseal presented similar root canal adaptation, solubility, flow, and film thickness. Statistical differences were found for radiopacity and setting time (P<.05). (J Endod 2011;37:1417-1421)

Tratamento de perfurações radiculares com pasta de hidróxido de cálcio e iodofórmio : influência da aplicação de curativo à base de corticóides; estudo histológico em dentes de cão

Esta pesquisa teve como proposta avaliar histopatologicamente,os efeitos do tratamento de perfurações radiculares, empregando medicamentos à base de corticóide e antibiótico como curativo, seu posterior preenchimento com uma pasta aquosa de hidróxido de cálcio e iodofórmio e, também, a utilização dessa pasta durante todo o período experimental. Para tanto, foram utilizados os segundos e terceiros pré-molares superiores e os terceiros e quartos inferiores de 6 cães adultos jovens. Nestes dentes, sob isolamento absoluto do campo operatório com dique de borracha, efetuou-se a obturação dos canais radiculares, e após a limpeza da câmara pulpar, procedeu-se a perfuração radicular na raiz mesial para a região interradicular e lateralmente disposta à furca. Como curativo foram utilizados o Rifocort e o Otosporin, que permaneciam por 7 dias no trajeto perfurado e em contato com os tecidos periodontais da região. Passado esse período, o curativo era substituído por uma pasta aquosa de hidróxido de cálcio e iodofórmio e todos os dentes eram radiografados antes e depois da substituição do material. Decorridos 90 dias, os animais foram sacrificados por meio de perfusão e as peças removidas, radiografadas e preparadas para se obter cortes histológicos, os quais foram corados pela hematoxilina e eosina e pelo tricrômico de Masson. Pelos resultados obtidos neste trabalho, é válido concluir que: a) as perfurações seladas imediatamente com a pasta aquosa de hidróxido de cálcio e iodofórmio apresentaram melhores resultados no exame histológico, onde ficaram evidenciadas menor quantidade do processo inflamatório e maior hiper-plasia de cemento; b) não houve diferença significante entre as perfurações tratadas com os medicamentos Rifocort e Otosporin; c) os dentes cujas perfurações permaneceram sem nenhum tratamento durante 7 dias, exibiram uma resposta menos favorável e sem evidência de reparação na área perfurada; d) as imagens radiográficas, no que se refere á extensão de destruição do tecido ósseo alveolar, foram compatfveis com os quadros histológicos, não havendo evidências, porém, da neoformação do tecido cementário.

Avaliação da eficiência da técnica de obturação pela compressão hidrùlica vertical após instrumentação automatizada

The purpose of this study was to evaluate through radiographic and microscopic analysis the efficiency of the filling techniques by vertical hidraulic compression after the root canal mechanical instrumentation in vitro as well to evaluate the marginal apical leakage through macroscopic and microscopic analysis. Thirty human mandibular molars were used , they were divided on three groups, these were subdivided on six subgroups with five specimens each, come down to 106 root canals filled. Initially, the teeth were instrumented with Profile system series 29 and filled with two ways: single accessory cone or single cone associated with gutta-percha secundary cone, with Fill Canal sealer or Sealer 26. Completed the filling, the teeth were coated with araldit and finger -nail polish except for the apical 2 mm and dried for 3 hours, thep radiographs were taken of the teeth in orto and disto-radiai directions. Next, the coronal seal was carried out with composite resin photopolymerized and with their process of making impermeable. Teeth of positive controls were used without araldit and finger-nail polish whereas the negative controls were used with total coat of araldit and finger-nail polish. The specimens were placed in 2% Methylene Blue dye for 24 hours and thermocycled for 7 days. Afterwards, sections were made of each tooth at mesial and distal roat, after this the teeth were radiographed at buccolíngual direction for a macroscopic analysis and at buccolingual and mesiodistal directions for assessment of the marginal apical leakage. Cross sections were made 3 mm to 3mm since the tooth apice. The sections obtained for each group were observed with a stereomicroscope to evaluate the quality of the root canal filling and the marginal apical leakage. The results showed that: In the four techniques the marginal dye leakage was present in the apical third; in all groups the quality of the root canal filling in the radiography was better at mesial root canal and the single cone technique showed inefficient when only a single distal root canal was present. In the radiographic evaluation the best quality of the root canal filling was observed in the 1A group (single accessory cone + FiIl Canal), as in the mesial root as in the distal root wich Shcwed twe root canals: when the distaI root had only one canal. the best result was showed by 28 group (single accessory cone associated with secundary cone + Fill Canal) In the macroscopic analysis of longitudinal !eaKage (outside surface). less leakage was showed as In the mesial root as in the distal root in the negative control group (3) followed 2A group (single accessory cone + Sealer 26). When the microscopic analysis of tranversal leakage of both roots (inside surface) was carried out. the groups that showed less dye leakage were the negative control (38) followed the 28 group (single acessory cone associated with secundary cone + Sealer 26). The homogeneity o filling was best noted in the 1 A group (.single accessoty cone + Fill Canal). The groups that showed less dye penetration in the tranversal leakage (total area) were negative control (3B) and 2B

Biocompatibility in vitro tests of mineral trioxide aggregate and regular and white Portland cements

Mineral trioxide aggregate (MTA) and Portland cement are being used in dentistry as root end-filling materials. However, biocompatibility data concerning genotoxicity and cytotoxicity are needed for complete risk assessment of these compounds. In the present study, genotoxic and cytotoxic effects of MTA and Portland cements were evaluated in vitro using the alkaline single cell gel (comet) assay and trypan blue exclusion test, respectively, on mouse lymphoma cells. The results demonstrated that the single cell gel (comet) assay failed to detect DNA damage after a treatment of cells by MTA and Portland cements for concentrations up to 1000 mu g/ml. Similarly, results showed that none of the compounds tested were cytotoxic. Taken together, these results seem to indicate that MTA and Portland cements are not genotoxins and do not induce cellular death.

Short-term vs long-term calcium hydroxide therapy after immediate tooth replantation: a histomorphometric study in monkey's teeth

Endodontic treatment is an important step of tooth replantation protocols, but the ideal moment for definitive obturation of replanted teeth has not yet been established. In this study, a histomorphometric analysis was undertaken to evaluate the repair process on immediate replantation of monkeys teeth after calcium hydroxide (CH) therapy for 1 and 6 months followed by root canal filling with a CH-based sealer (Sealapex (R)). The maxillary and mandibular lateral incisors of five female Cebus apella monkeys were extracted, kept in sterile saline for 15 min, replanted and splinted with stainless steel orthodontic wire and composite resin for 10 days. In Group I (control), definitive root canal filling was performed before tooth extraction. In Groups II and III, CH therapy started after removal of splint, and definitive root canal filling was performed 1 and 6 months later, respectively. The animals were euthanized 9 months after replantation, and specimens were processed for histomorphometric analysis. In all groups, epithelial attachment occurred at the cementoenamel junction or very close to this region; the areas of resorption on root surface had small extension and depth and were repaired by newly formed cementum; and the periodontal ligament was organized. Statistical analysis of the scores obtained for the histomorphometric parameters did not show any statistically significant difference (P = 0.1221) among the groups. The results suggests that when endodontic treatment is initiated 10 days after immediate replantation and an antibiotic regimen is associated, definitive root canal filling can be performed after a short-term CH therapy.

Sealability of MTA and calcium hydroxide-containing sealers

Objectives: The aim of this study was to evaluate the apical sealability of Fillapex (R), Endo-CPM-Sealer (R) and Sealapex (R). Material and Methods: Ninety-four freshly extracted single-rooted teeth were selected and decoronated. All teeth were radiographed to confirm the existence of a single and straight root canal, which was prepared using Protaper Universal and 2.5% sodium hypochlorite. The teeth were randomly divided in groups of 10 specimens each according to the sealer, and the canals were filled using the single cone technique and one of the sealers. Four additional teeth were used as controls. The teeth were submitted to dye leakage with Rhodamine B for 24 h but using vacuum on the initial 15 min. Thereafter, they were cut longitudinally and the leakage was measured in a linear fashion from apex to crown. Data were analyzed by ANOVA and Tukey's tests at 5% significance level. Results: Fillapex (R) and Sealapex (R) showed significantly less dye leakage than Endo-CPM-Sealer (R) (p<0.05). Conclusions: It was concluded that Fillapex (R) and Sealapex (R) were able to prevent apical dye leakage differently from Endo-CPM-Sealer (R).