Physicochemical properties and filling capacity of an experimental iodoform-based paste in primary teeth

Abstract In this study, we evaluated the physicochemical properties (PCP; radiopacity, flow, pH, and solubility) and the quality of root canal filling provided by an experimental industrialized paste (EP), with the same active ingredients as those of the Guedes Pinto paste, compared with the Vitapex® paste. PCP were analyzed according to the ANSI/ADA laboratory testing methods for endodontic filling and sealing materials. To analyze filling capacity, 120 artificial primary teeth (60 maxillary incisors [MIs] and 60 mandibulary molars [MMs]) were endodontically treated. The teeth were divided into eight groups based on the dental group (MIs or MMs), filling material (Vitapex® or EP), and insertion method (syringe or lentulo). The Image J® software was used to analyze the initial an final digital radiographies of each tooth, measuring and comparing root canal and void areas. The percentage of filling failure areas was obtained. Data were submitted to ANOVA and Tukey test of mean comparison. Regarding PCP, both pastes presented results according the ANSI/ADA standards. Flow capacity: Vitapex: 19.6 mm, EP: 25 mm (p < 0.01); radiopacity: Vitapex: 4.47 mmAl, EP: 6.06 mmAl (p < 0.01); pH after 28 days: Vitapex: 7.79, EP: 8.19 (p = 0.12); and solubility after 28 days: Vitapex: 2.68%, EP: 2.89% (p > 0.05). Regarding filling capacity analysis, EP demonstrated 12.5% of failure against 31.5% of Vitapex (p < 0.01). Compared to Vitapex, EP presented statistically significantly better results in flow, radiopacity, pH, and filling capacity. Molars presented more filling failures than incisors. The insertion method using a syringe and a thin tip was significantly better than that using Lentulo spiral carriers.

Craneosinostosis sindrómica: Características craneodentofaciales, tratamiento ortodón-tico-quirúrgico y factores asociados a tipos de síndrome / Craniossinostose sindrômica: Características craniodentofaciais, tratamento ortodônti-co-cirúrgico e fatores associados aos tipos de síndrome / Syndromic Craniosynostosis: Craniodentofacial features, orthodontic-surgical treatment and factors associated to types of syndrome

Objetivos: Describir las características craneodentofaciales, tratamientos ortodónticos-quirúrgicos y establecer una aso-ciación entre los tipos de síndrome presentes en pacientes con craneosinostosis sindrómica (CS). Material y métodos: Estudio retrospectivo de registros médicos y de ortodoncia de pacientes con CS. Los datos se recogieron en una forma específica y se sometieron a un análisis estadístico descriptivo para observar la distribución de frecuencias y se utilizó la prueba de Chi cuadrado con un nivel de significación del 5% para asociar el síndrome y los tipos de variables. Resultados: El síndrome de Crouzon fue el tipo predominante (59.2%) y la braquicefalia fue el tipo más frecuente de craneosinostosis (63.6%). Hubo una asociación significativa entre las variables braquicefalia (p = 0,014), presencia de paladar hendido (p = 0,043), mordida cruzada posterior (p = 0,013), distracción osteogénica realizada por elásticos intermaxilares (p = 0,030), barra de Erich (p = 0.007) y la extracción (p = 0.041) y los síndromes estudiados. Conclusión: Los pacientes con CS a menudo tienen cambios craneodentofaciais y algunas variables tienen asociaciones significativas en relación con los tipos de síndromes.

Objectives: Describe the craniodentofacial characteristics, orthodontic-surgical treatments and establish an association between the syndrome types present in patients with syndromic craniosynostosis (SC). Material and methods: Retros-pective study of medical and orthodontic records of patients with SC. Data was collected on a specific form and subjected to descriptive statistical analysis to observe the distribution of frequencies and chi-square test with level of significance of 5% was used to associate syndrome and the types of variables. Results: Crouzon syndrome was the predominant type (59.2%) and brachycephalia was the most prevalent type of craniosynostosis (63.6%). There was a significant association between the variables brachycephaly (p=0.014), presence of cleft palate (p=0.043), posterior cross bite (p=0.013), distrac-tion osteogenesis performed by intermaxillary elastics (p= 0.030), Erich bar (p= 0.007) and extraction (p=0.041) and the syndromes studied. Conclusion: Patients with SC often have craniodentofaciais changes and some variables had signifi-cant associations in relation to the types of syndromes.

Descrever as características craniodentofaciais, tratamentos ortodôntico-cirúrgicos e estabelecer uma associação entre os tipos de síndrome presentes em pacientes com craniossinostose sindrômica (CS). Material e métodos: Estudo retrospectivo de prontuários médicos e ortodônticos de pacientes com CS. Os dados foram coletados em formulário específico e submetidos à análise estatística descritiva para observar a distribuição das frequências e o teste qui-quadrado com nível de significância de 5% foi utilizado para associar a síndrome e os tipos de variáveis. Resultados: A síndrome de Crouzon foi o tipo predominante (59,2%) e a braquicefalia foi o tipo mais prevalente de craniossinostose (63,6%). Houve associação significativa entre as variáveis braquicefalia (p = 0,014), presença de fissura de palato (p = 0,043), mordida cruzada posterior (p = 0,013), distração osteogênica realizada pelos elásticos intermaxilares (p = 0,030), barra de Erich (p= 0,007) e extração (p = 0,041) e as síndromes estudadas. Conclusão: Pacientes com CS frequentemente apresentam alterações craniodentofaciais e algumas variáveis apresentaram associações significativas em relação aos tipos de síndromes.

Low-intensity laser phototherapy enhances the proliferation of dental pulp stem cells under nutritional deficiency

Abstract Dental trauma in immature permanent teeth can damage pulp vascularization, which leads to necrosis and cessation of apexogenesis. Studies on tissue engineering using stem cells from human exfoliated deciduous teeth (SHEDs) have yielded promising results. Laser phototherapy (LPT) is able to influence the proliferation and differentiation of these cells, which could improve tissue engineering. SHEDs (eighth passage) were seeded into 96-well culture plates (103 cells/well) and were grown in culture medium supplemented with 15% defined fetal bovine serum (FBS) for 12 h. After determining the appropriate nutrition deficiency status (5% FBS), the cells were assigned into four groups: 1) G1 - 15% FBS (positive control); 2) G2 - 5% FBS (negative control); 3) G3 - 5% FBS+LPT 3 J/cm2; and 4) G4 - 5% FBS+LPT 5 J/cm2. For the LPT groups, two laser irradiations at 6 h intervals were performed using a continuous wave InGaAlP diode laser (660 nm, with a spot size of 0.028 cm2, 10 mW) in punctual and contact mode. Cell viability was assessed via an MTT reduction assay immediately after the second laser irradiation (0 h) and 24, 48, and 72 h later. We found that G3 and G4 presented a significantly higher cell growth rate when compared with G2 (p < 0.01). Moreover, G4 exhibited a similar cell growth rate as G1 throughout the entire experiment (p > 0.05). These findings indicate that LPT with 5 J/cm2 can enhance the growth of SHEDs during situations of nutritional deficiency. Therefore, LPT could be a valuable adjunct treatment in tissue engineering when using stem cells derived from the dental pulp of primary teeth.

CT study of the performance of reciprocating and oscillatory motions in flattened root canal areas

Root canal preparation is an important step in endodontic treatment. The anatomical complexity of the middle third of the root compromises the effective cleaning of this area. Thus, advances have been made in instrumentation techniques and instruments for this purpose. The aim of this study was to evaluate the effects of three different instrumentation systems on the enlargement of the middle thirds of root canals in mandibular incisors. The preparation methods used were the reciprocating systems Reciproc (Group I) and WaveOne (Group II) and the oscillatory system Tilos (Group III). Comparisons were made by three-dimensional image reconstruction with cone-beam computed tomography before and after instrumentation. Changes in area, perimeter, centering ability, and pattern of preparation were analyzed. The results were subjected to ANOVA complemented by the Tukey’s test. Changes in area, perimeter, and tendency of transportation showed similar results among groups. The transportation index of the Tilos system was significantly lower than that of the other groups. Qualitative analysis of the preparation pattern showed that the Tilos system had a more uniform preparation, although Reciproc and WaveOne preparations appeared more rounded, incompatible with the original canal anatomy. There was similarity in the systems’ performance on flattened areas, although the Tilos system presented a better pattern of root canal preparation and a lower index of transportation.

Changes in irradiance and energy density in relation to different curing distances

The present study aimed to assess the influence of curing distance on the loss of irradiance and power density of four curing light devices. The behavior in terms of power density of four different dental curing devices was analyzed (Valo, Elipar 2, Radii-Cal, and Optilux-401) using three different distances of photopolymerization (0 mm, 4 mm, and 8 mm). All devices had their power density measured using a MARC simulator. Ten measurements were made per device at each distance. The total amount of energy delivered and the required curing time to achieve 16 J/cm2 of energy was also calculated. Data were statistically analyzed with one-way analysis of variance and Tukey’s tests (p < 0.05). The curing distance significantly interfered with the loss of power density for all curing light devices, with the farthest distance generating the lowest power density and consequently the longer time to achieve an energy density of 16 J/cm2 (p < 0.01). Comparison of devices showed that Valo, in extra power mode, showed the best results at all distances, followed by Valo in high power mode, Valo in standard mode, Elipar 2, Radii-Cal, and Optilux-401 halogen lamp (p < 0.01). These findings indicate that all curing lights induced a significant loss of irradiance and total energy when the light was emitted farther from the probe. The Valo device in extra power mode showed the highest power density and the shortest time to achieve an energy density of 16 J/cm2 at all curing distances.

Penetration of a resin-based filling material into lateral root canals and quality of obturation by different techniques

The aim of this study was to evaluate the penetration of a resin/polyester polymer-based material (Resilon Real Seal; SybronEndo Corp., Orange, USA) into simulated lateral canals, and the quality of obturations by different techniques. A total of 30 standardized simulated canals were divided into three groups according to the technique of obturation used: MS (McSpadden), SB (SystemB/Obtura II), and LC (Lateral Condensation). To analyze the penetration of the filling material, the simulated canals were digitalized and the images were analyzed using the Leica QWIN Pro v2.3 software. The data of the middle and apical thirds were separately submitted to analysis of variance (ANOVA), followed by the Tukey’s test for the comparison of the techniques. Results showed a significant difference (p < 0.05) between groups (LC < SB) in the middle third, and a significant difference (p < 0.05) between groups (LC < SB and MS < SB) in the apical third. To analyze the quality of the obturations, the canals were radiographed and evaluated by three examiners. The Kappa test on interexaminer agreement and the nonparametric Kruskal-Wallis test indicated no significant difference between filling techniques. It was concluded that Resilon achieves greater levels of penetration when associated with thermoplastic obturation techniques.

Como podemos otimizar a endodontia em dentes decíduos?: relato de caso / How can we optimize endodontics in primary teeth?: a reported case

O tratamento endodôntico em dentes decíduos decorrente de lesões cariosas ou traumáticas com envolvimento pulpar muitas vezes é necessário na Clínica Odontopediátrica. Entretanto, nota-se que a qualidade da técnica endodôntica em dentes decíduos muitas vezes é deixada de lado, justificada pelo difícil comportamento das crianças e pelas características anatômicas internas dos dentes decíduos. Assim, seria interessante resgatar e agregar novos conceitos à endodontia de dentes decíduos para facilitar o dia-a-dia clínico e otimizar o tratamento. Este trabalho teve como objetivo descrever um caso clínico de uma paciente atendida na Clinica de Graduação de Odontopediatria da Uniararas, onde se realizou o tratamento endodôntico no incisivo central superior decíduo esquerdo, através de uma nova proposta que tem por objetivo melhorar a qualidade da técnica endodôntica em dentes decíduos utilizando localizadores apicais eletrônicos e um sistema de instrumentação mecanizado. Concluiu-se que a utilização de novas tecnologias apresentou-se como uma alternativa viável no tratamento endodôntico do incisivo decíduo relatado, auxiliando e alcançando um resultado satisfatório em relação ao preparo mecânico do conduto e ao seu preenchimento com o material obturador. Mais estudos futuros deveriam ser realizados para avaliar a utilização dessas novas tecnologias no tratamento endodôntico de dentes decíduos.

The endodontic treatment in primary teeth due to caries or trauma with pulp involvement is often necessary in Pediatric Dentistry. However, it has been observed that the technical quality of endodontic primary teeth is often left out justified by the difficult behavior of children and the internal anatomical features of the deciduous teeth. Thus, it would be interesting to recover and add new concepts to endodontics in primary teeth to facilitate the day-to-day clinical and optimized treatment. The aim of this study was to describe a clinical case of a patient treated in the Pediatric Dentistry Clinic of the Graduate UNIARARAS, where they performed endodontic treatment in deciduous left maxillary central incisor, through a new proposal, which aims to improve the quality of endodontic technique in primary teeth using electronic apex locators, ultrasound, mechanical instrumentation system. It was concluded that the use of new technologies introduced as a viable alternative to endodontic treatment of deciduous incisor reported, aiding and achieving a satisfactory outcome in relation to the mechanical preparation of the canal and fill it with filling material. Further studies should be performed to evaluate the use of these new technologies in endodontic treatment of deciduous teeth.

Micro-CT assessment of two different endodontic preparation systems

The aim of this study was to compare two endodontic preparation systems using micro-CT analysis. Twenty-four one-rooted mandibular premolars were selected and randomly assigned to two groups. The samples (n = 12) of Group 1 were prepared using the ProTaper Universal rotary system, while Group 2 (n = 12) was prepared using the EndoEZE AET system complemented by manual apical preparation with K-type hand files up to #30. A 2.5% sodium hypochlorite solution was used in both groups for irrigating. Both groups were scanned by high-resolution microcomputed tomography before and after preparation (SkyScan 1172, SkyScan, Kontich, Belgium). The root canal volume and surface area was measured before and after preparation, and the differences were calculated and analyzed for statistically significant differences using ANOVA complemented by the Tukey test (p < 0.05). The results showed no statistically significant differences between the mean volumes of dentin removal by the two systems. However, the EndoEZE AET system presented a significantly greater mean surface area compared to the ProTaper system (p < 0.05). The EndoEZE AET system enabled preparation of a greater root canal surface area when compared to the ProTaper Universal system. There seemed to be no difference in dentin volume loss between the two systems used.

Influence of prior 810-nm-diode intracanal laser irradiation on hydrophilic resin-based sealer obturation

Dentin wall structural changes caused by 810-nm-diode laser irradiation can influence the sealing ability of endodontic sealers. The objective of this study was to evaluate the apical leakage of AH Plus and RealSeal resin-based sealers with and without prior diode laser irradiation. Fifty-two single-rooted mandibular premolars were prepared and divided into 4 groups, according to the endodontic sealer used and the use or non-use of laser irradiation. The protocol for laser irradiation was 2.5W, continuous wave in scanning mode, with 4 exposures per tooth. After sample preparation, apical leakage of 50% ammoniacal silver nitrate impregnation was analyzed. When the teeth were not exposed to irradiation, the RealSeal sealer achieved the highest scores, showing the least leakage, with significant differences at the 5% level (Kruskal-Wallis test, p = 0.0004), compared with AH Plus. When the teeth were exposed to the 810-nm-diode laser irradiation, the sealing ability of AH Plus sealer was improved (p = 0282). In the RealSeal groups, the intracanal laser irradiation did not interfere with the leakage index, showing similar results in the GRS and GRSd groups (p = 0.1009).

Nd:YAG laser irradiation effect on apical intracanal dentin - a microleakage and SEM evaluation

The purpose of this in vitro study was to evaluate the effect of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser irradiation on intracanal dentin surface by SEM analysis and its interference in the apical seal of filled canals. After endodontic treatment procedures, 34 maxillary human incisors were randomly assigned to 2 groups. In the negative control group (n=17), no additional treatment was performed and teeth were filled with vertically condensed gutta-percha; in the laser-treated group (n=17), the root canals were irradiated with Nd:YAG laser (1.5 W, 100 mJ, 15 Hz) before filling as described for the control group. Two specimens of each group were prepared for SEM analysis to evaluate the presence and extent of morphological changes and removal of debris; the other specimens were immersed in 0.5 percent methylene blue dye (pH 7.2) for 24 h for evaluation of the linear dye leakage at the apical third. SEM analysis of the laser-treated group showed dentin fusion and resolidification without smear layer or debris. The Student’s t-test showed that the laser-treated group had significantly less leakage in apical third than the control group. Within the limitations of this study, it may be concluded that the morphological changes on the apical intraradicular dentin surface caused by Nd:YAG laser resulted in less linear dye apical leakage.

Accuracy of three electronic apex locators in the presence of different irrigating solutions

The present study compared the accuracy of three electronic apex locators (EALs) - Elements Diagnostic®, Root ZX® and Apex DSP® - in the presence of different irrigating solutions (0.9 percent saline solution and 1 percent sodium hypochlorite). The electronic measurements were carried out by three examiners, using twenty extracted human permanent maxillary central incisors. A size 10 K file was introduced into the root canals until reaching the 0.0 mark, and was subsequently retracted to the 1.0 mark. The gold standard (GS) measurement was obtained by combining visual and radiographic methods, and was set 1 mm short of the apical foramen. Electronic length values closer to the GS (± 0.5 mm) were considered as accurate measures. Intraclass correlation coefficients (ICCs) were used to verify inter-examiner agreement. The comparison among the EALs was performed using the McNemar and Kruskal-Wallis tests (p < 0.05). The ICCs were generally high, ranging from 0.8859 to 0.9657. Similar results were observed for the percentage of electronic measurements closer to the GS obtained with the Elements Diagnostic® and the Root ZX® EALs (p > 0.05), independent of the irrigating solutions used. The measurements taken with these two EALs were more accurate than those taken with Apex DSP®, regardless of the irrigating solution used (p < 0.05). It was concluded that Elements Diagnostic® and Root ZX® apex locators are able to locate the cementum-dentine junction more precisely than Apex DSP®. The presence of irrigating solutions does not interfere with the performance of the EALs.

Evaluation of the maxillary premolar roots dissociation using radiographic holders with conventional and digital radiography

This in vivo study evaluated the dissociation quality of maxillary premolar roots combining variations of vertical and horizontal angulations by using X-ray holders (Rinn -XCP), and made a comparison between two types of intraoral radiography systems - conventional film (Kodak Insight, Rochester, USA) and digital radiography (Kodak RVG 6100, Kodak, Rochester, USA). The study sample was comprised of 20 patients with a total of 20 maxillary premolars that were radiographed, using the paralleling angle technique (GP), with a 20º variation of the horizontal angle (GM) and 25º variation of the horizontal angle combined with 15º vertical angle (GMV). Each image was independently analyzed by two experienced examiners. These examiners assigned a score to the diagnostic capability of root dissociation and the measurement of the distance between the apexes. Statistical data was derived using the Wilcoxon Signed Rank test, Friedman and T test. The means of the measured distances between buccal and lingual root apexes were greater for the GMV, which ranged from 2.3 mm to 3.3 mm. A statistically significant difference was found between GM and GMV when compared to GP with p < 0.01. An established best diagnostic dissociation roots image was found in the GMV. These results support the use of the anterior X-ray holders which offer a better combined deviation (GMV) to dissociate maxillary premolar roots in both radiography systems.

In vitro analysis of thermocompaction time and gutta-percha type on quality of main canal and lateral canals filling

The aim of this study was to evaluate the quality of filling in main and lateral root canals performed with the McSpadden technique, regarding the time spent on the procedure and the type of gutta-percha employed. Fifty simulated root canals, made with six lateral canals placed two apiece in the cervical, middle and apical thirds of the root, were divided into 5 groups. Group A: McSpadden technique with conventional gutta-percha, performed with sufficient time for canal filling; Group B: McSpadden technique with conventional gutta-percha, performed in twice the mean time used in Group A; Group C: McSpadden technique with TP gutta-percha, performed with sufficient time for canal filling; Group D: McSpadden technique with TP gutta-percha, performed in twice the mean time used in Group C; Group E: lateral condensation technique. Images of the filled root canals were taken using a stereomicroscope and analyzed using the Leica QWIN Pro software for filling material flow, gutta-percha filling extension and sealer flow. Data were analyzed by analysis of variance (ANOVA) and Tukey test (p < 0.05). The best values of penetration in lateral canals in the middle third occurred in the groups where TP gutta-percha was used. However, in the apical third, group B showed the best values. Although a longer time of compactor use allows greater penetration of the filling material into the lateral canals, the presence of voids resulted in bad quality radiographic images, suggesting porosity. The best quality of filling material was observed in Group A (McSpadden technique with conventional Gutta-Percha, performed with sufficient time for root canal filling).

Ex vivo analysis of root canal cleaning using Endo-PTC associated to NaOCl and different irrigant solutions

The aim of this study was to assess qualitatively, by means of SEM images, the cleaning of the dentin walls of root canals after chemical-surgical preparation using Endo-PTC cream with 0.5 percent and 1 percent sodium hypochlorite and different final irrigating solutions. Seventy-two single-rooted human teeth were divided into eight groups and prepared using Endo-PTC cream with sodium hypochlorite (NaOCl) at different concentrations, and irrigated with NaOCl at different concentrations. Final irrigation was performed with either EDTA-T or EDTA-C. The best results were obtained with Group 1, followed by Groups 5, 2, 7, 8, 3, 6 and 4. We can conclude that the use of 0.5 percent NaOCl during instrumentation and final flush of the root canals was more efficient in cleaning than was 1 percent sodium hypochlorite. EDTA-T was more efficient in removing smear layer than EDTA-C, and the cervical third presented better cleaning of the root canal walls than did the middle third, which showed cleaner dentin walls than the apical third.

Comparação in vitro do tratamento das perfurações de furca com agregado de trióxido mineral e amálgama de prata / In vitro study comparison of furcal perforations treatments using mineral trioxide aggregate and silver amalgam

Introdução - A perfuração na região de furca é considerada um dos mais sérios fatores para o fracasso do tratamento endodôntico. Baseado nisso, o objetivo do estudo foi comparar a capacidade seladora do amálgama de prata e do MTA em perfurações de furca. Materiais e Métodos - Foram utilizados 24 molares superiores e inferiores, que após cirurgia de acesso, tiveram uma perfuração na região da furca feita com broca carbide nº 3 em alta rotação. As paredes externas foram impermeabilizadas com cianoacrilato de etila e os espécimes foram divididos em dois grupos experimentais, com 10 elementos cada, onde G1 foi vedado com MTA e G2 com amálgama de prata. Os dentes foram, então, imersos em corante azul de metileno por 24 horas e, posteriormente, seccionados longitudinalmente para mensuração das infiltrações, classificadas em 3 níveis. Resultados - Sete elementos do Grupo 1 não apresentaram infiltração de corante e 3 tiveram pequena infiltração. Já no Grupo 2, apenas 2 dentes não demonstraram infiltração enquanto que o restante ficou igualmente dividido entre infiltração pequena e severa. O teste de Kruskal-Wallis revelou diferenças significantes entre os grupos experimentais. Conclusão - É lícito concluir que o MTA apresenta capacidade superior para o vedamento das perfurações de furca do que o amálgama de prata.

Introduction - Furcal perforation is considered one of the most serious factors for the endodontic treatment failure. Based on this, the aim of this study was to compare the marginal sealing promoted by the amalgam and MTA in the furcal perforations. Materials and Methods - In present study were used 24 upper and lower molars were used. After the endodontic access, a perforation in the furcal area was made with a carbide drill #3. The external teeth walls received two layers of ethyl cyanoacrylate and then, the specimens were divided in two experimental groups, with 10 teeth each, where G1 was sealed with MTA and G2 with amalgam. The teeth were immersed in methylene blue dye for 24 hours and after that, split longitudinally to measure the leakage index, classified in three levels. Results - Seven samples of Group 1 did not show dye leakage and two showed small leakeage. In Group 2, only 2 specimens did not have any sign of dye leakage whereas the rest of them was divided in small and severe leakage. Kruskal-Wallis test showed significant differences between experimental groups. Conclusion - It was conclude that MTA promoted a better seal for furcal perforations than the amalgam.

Aplicações clínicas da tomografia computadorizada cone beam na Endodontia / Clinical applications of cone beam computed tomography in endodontics

A necessidade em avaliar estruturas em três dimensões na prática endodôntica é notada especialmente em casos complexos, nos quais as radiografias convencionais não revelam com exatidão aspectos importantes para se obter um correto diagnóstico e planejamento do tratamento. A tomografia computadorizada cone beam tem sido muito utilizada na área odontológica, sendo o objetivo deste trabalho uma revisão da literatura sobre a sua aplicabilidade na Endodontia. Concluiu-se que a CBCT é um importante recurso auxiliar na prática endodôntica, principalmente para a localização de canais radiculares, identificação de lesões patológicas, reabsorções e fraturas radiculares.

The need to evaluate structures in 3D in endodontics practice is noticed especially in complex cases, in which conventional radiographs do not reveal, in an accurate way, important aspects to obtain a correct diagnosis and planning. The cone beam computed tomography has been used in the dental , with the aim of this article a review of the literature about its applicability in endodontics. It was concluded that the CBCT is an important resource to assist in endodontic practice, especially for the location of root canals, identification of pathological lesions, root resorption and fractures.

Avaliação da permeabilidade radicular em dentes com rizogênese incompleta após aplicação de hidróxido de cálcio como medicação intracanal / Root permeability evaluation in immature permanent teeth after calcium hydroxyde application as intra root medication

Introdução - Foi avaliada a possível variação da permeabilidade dentinária radicular, em dentes com rizogênese incompleta, após medicação com hidróxido de cálcio veiculado em solução anestésica. Material e Métodos - Decorrido o prazo experimental, os dentes foram re-preparados com quatro diferentes técnicas de remoção da medicação, avaliando-se quantitativamente o índice de permeabilidade dentinária radicular, através da penetração do corante azul de metileno. Observou-se existir diferença estatisticamente significante quanto à porcentagem de penetração de corante em função do tipo de técnica usada na remoção da medicação. Resultados - O uso do EDTA-T seguido ao seu final pelo creme de Endo-PTC neutralizado pelo hipoclorito de sódio a 1%, foi o que melhor proporcionou um aumento no índice de permeabilidade pós-medicação, devolvendo ao dente a condição prévia de permeabilidade conseguida após o preparo químico-cirúrgico, não havendo diferença estatisticamente significante ao nível de 5% entre o Grupo 2 e 6, nos diferentes terços radiculares. Conclusões - A medicação com hidróxido de cálcio interferiu, de forma decisiva, no índice de permeabilidade dentinária radicular, independente do terço radicular analisado

Avaliação da temperatura mínima alcançada por cinco gases refrigerantes / Lowest temperature reached by five cold spray gases

Introdução - O uso de gases refrigerantes é um método largamente utilizado no diagnóstico de possíveis alterações inflamatórias pulpares. O objetivo deste estudo foi avaliar a capacidade destes gases em atingir baixas temperaturas. Material e Métodos - Foram avaliados cinco gases refrigerantes (tetrafluoretano, hidrofluorcarbono, propano/butano e duas associações de butano, etanol, benzoato de sódio, água desmineralizada e mentol) com o auxílio de um termômetro eletrônico digital. Resultados - Após a análise dos resultados, utilizando o teste ANOVA (Tukey), ocorreram diferenças estatisticamente significantes (p<0,01) entre todos os grupos estudados, com exceção da comparação entre os gases hidrofluorcarbono e tetrafluoretano (p>0,05). Conclusão - O hidrofluorcarbono foi o gás que atingiu o menor nível de temperatura, seguido pelo tetrafluoretano e propano/butano.

Introduction - The cold spray gases are frequently used as a diagnosis method of possible pulpal inflammatory alterations. The objective of this study was to evaluate the capacity of these gases to reach low temperatures. Material and Methods - They were evaluated 5 cold spray gases (tetrafluorethane, hydrofluorocarbon, propane/butane and two associations of butane, ethanol, sodium benzoate, distilled water and menthol) with the assist of a digital electronic thermometer. Results - After the results analysis, using ANOVA (Tukey test), statistically significant differences (p<0,01) occurred among all of the studied groups, excepting the comparison between hydrofluorocarbon and tetrafluorethane gases. Conclusion - It was concluded that hydrofluorocarbon gas reached the lowest temperature level, following by tetrafluorethane and propane/butane gases.

Análise comparativa do preparo químico-cirúrgico através das técnicas automatizada híbrida e escalonada em canais curvos / Comparative analysis of the chemical-surgical preparation through the automatized hybrid and step-back techniques in curved canals

Introdução - O presente trabalho teve por objetivo avaliar o desvio apical, em raízes mésio-vestibulares de molares superiores, valendo-se de técnica escalonada e técnica mecânico-rotatória Híbrida. Métodos - Foram utilizados 20 dentes molares superiores extraídos e radiografados no sentido vestíbulo – lingual. Procedeu-se a cirurgia de acesso, esvaziamento e odontometria de cada dente e os mesmos foram divididos em dois grupos: GI - técnica manual escalonada e GII - técnica Híbrida. As limas utilizadas foram as do tipo “K” n. 10 e 15 marca Maillefer, limas tipo Flexofile – 1ª serie (15 – 40) 21mm marca Maillefer e limas do sistema Profile 0.4 Maillefer de n. 20 a 35. Durante a instrumentação, utilizou-se como substâncias químicas auxiliares o creme Endo PTC – neutralizado pela solução de hipoclorito de sódio 0,5% e EDTA – T, na irrigação final. Os canais foram secos com cones de papel. A seguir, injetou-se o material de moldagem tipo silicona de condensação no interior de cada conduto radicular preparado. E, então, foram imersos em solução de acido clorídrico a 35% por, aproximadamente, 12hs, e descalcificados durante um período de 96hs. Obteve-se o molde do canal radicular preparado e cada um foi analisado com o auxílio de uma lente com 20 vezes de aumento. Resultados - Apenas um dente em cada grupo apresentou desvio apical. Conclusão - As técnicas de instrumentação propostas para canais curvos , escalonada e híbrida mecanizada, não apresentaram diferenças estatisticamente significantes , ao nível de 5%, no que se refere à ocorrência de desvio apical.

Introduction – The objective of the present study was to evaluate the apical displacement in upper molar vestibular mesial roots through step-back and Hybrid mechanical and rotatory techniques. Methods – Twenty extracted upper molars were used and their radiographies taken in the lingual vestibule direction. Access surgery was performed, as well as emptying and odontometry of each tooth, and the latter was divided into two groups: GI - manual step-back technique and GII - Hybrid technique. The files utilized were Maillefer, type “K” no. 10 and 15, Maillefer’s Flexofile – Series 1 (15 – 40) 21mm, and Maillefer’s Profile 0.4 no. 20 to 35. During instrumentation, Endo PTC cream was used as an auxiliary chemical substance – neutralized by a sodium hipochlorite solution at 0.5% and EDTA – T, in the final irrigation. The canals were dried with paper cones. Next, molding material of silicone condensation was injected in each prepared radicular space. Then, they were immersed in a chloride acid solution at 35% for approximately 12 hours, and decalcified for a period of 96 hours. A mold of the prepared radicular canal was obtained and each of them was analyzed through a 20X lens. Results – Only one tooth in each group presented apical displacement. Conclusion – The instrumentation techniques proposed for curved canals, step-back and mechanized hybrid, did not present statistically significant differences at 5%, with regard to the occurrence of apical displacement.

Análise comparativa entre dois métodos para determinação do grau de curvatura de canais radiculares / Comparative analysis between two methods for root canals curvature degree determination

O objetivo deste estudo foi comparar dois métodos para determinação do grau de curvatura de canais radiculares (ângulo de Schneider e método FKG). Métodos - Foram selecionadas 23 radiografias, realizadas pela técnica do paralelismo, de primeiros molares inferiores humanos com ápice completo e sem tratamento endodôntico, do Curso de Especialização em Endodontia da APCD - Regional São Caetno do Sul. Para a determinação do ângulo de Scheneider, as radiografias foram postas sobre um negatoscópio e nelas foram localizados três pontos sobre a raiz mesial: ponto A - orifício da entrada dos canais radiculares; ponto B - início da curvatura do canal radicular e ponto C - vértice radiográfico. O ponto A foi unido ao B por uma reta e este ao C por outra reta. Estas retas foram transferidas para uma folha, onde com o auxílio de um transferidor, determinou-se o ângulo de curvatura, classificando-o de acordo com a sua severidade em suave, moderada ou severa. Para determinar o grau de curvatura pelo método da FKG, procedeu-se sobrepondo a radiografia sobre a tabela com a da radiografia. As angulações da FKG foram mensuradas de acordo com o método de Schneider para transformar suas medidas em graus, permitindo uma análise comparativa entre os dois métodos. Resultados - A análise estatística dos resultados mostrou existir uma diferença estatisticamente significante ao nível de 1% (teste de Wilcoxon). Conclusões - Não há uma padronização entre os métodos comparados. Todas as angulações classificadas como moderadas pelo método de Scheneider foram consideradas suaves pela tabela da FKG e as angulações suaves e moderadas para a tabela da FKG foram consideradas severas pelo método de Scheneider. A classificação segundo a metodologia de Scheneider se mostra mais confiável em comparação à técnica com o uso da tabela da FKG