Effect of number of uses and sterilization on the instrumented area and resistance of reciprocating instruments.

OBJECTIVES: This study evaluated the effect of repeated uses and autoclaving in the instrumented area, fracture resistance, and time of instrumentation of thermally treated nickel-titanium reciprocating systems. MATERIALS AND METHODS: Two hundred simulated canals were instrumented using Reciproc Blue and WaveOne Gold. Each file was used up to 10 times or until fracture. The instrumented area was measured in pre- and post-operative images, using ImageJ software. Kaplan-Meier survival analysis evaluated the number of uses of instruments before fracture. Instrumented area and time of instrumentation were analyzed by Mann-Whitney U test and Kruskal-Wallis. Correlations among the number of uses and instrumented area were measured. The level of statistical significance was set at p < 0.05. RESULTS: Reciproc Blue presented a higher estimated number of uses in comparison with WaveOne Gold (p = 0.026), but autoclaving did not affect the resistance to fracture of instruments (p > 0.05). The instrumented area was different among the evaluated groups (p = 0.039), and the instrumented area along the uses of both tested instruments was reduced. With the time of instrumentation, there was also a significant difference among the evaluated groups; the groups without sterilization cycles were faster, in comparison to those submitted to autoclaving (p = 0.010). CONCLUSIONS: Reciproc Blue was more resistant than WaveOne Gold, suffering later fracture. Additionally, the sterilization cycles did not influence the estimated number of uses of thermally treated reciprocating instruments, but the instrumented area of root canals was reduced along with the repeated uses of both instruments.

Estudo in vitro da morfologia interna de pré-molares superiores e inferiores por meio de quatro métodos / In vitro study of maxillary and mandibular premolars internal morphology by means of four methods

O objetivo desse trabalho foi avaliar, in vitro, por meio de quatro critérios (radiográfico, macroscópico, microscópico e cortes seriados), a quantidade e configuração dos canais em pré-molares superiores e inferiores. Trata-se de um estudo transversal observacional e descritivo, no qual foram selecionados 100 pré-molares, tendo como critério de exclusão aqueles bastante destruídos por cárie, com tratamentos endodônticos prévios, rizogênese incompleta, reabsorções e/ou fraturas. Os dentes foram divididos em quatro grupos (n = 25): G1 = primeiros pré-molares superiores; G2 = segundos pré-molares superiores; G3 = primeiros pré-molares inferiores; e G4 = segundos pré-molares inferiores. Os resultados obtidos mostraram que 100% do G1 apresentaram dois canais radiculares na avaliação macroscópica, que se fundiam em várias alturas da raiz, possuindo maior prevalência de configuração oval (68%). O G2 revelou 60% de canais radiculares únicos e formato oval (84%). Os resultados obtidos no G3 foram raiz única e canal único (100%) e incidência de configuração oval (72%). Por fim, o G4 apresentou maior prevalência de um canal radicular em uma única raiz (92%) e prevalência de configuração oval (64%). Portanto, por meio da metodologia utilizada nesse estudo, houve prevalência de canais radiculares ovais em todos os grupos, predominando nos primeiros pré-molares superiores a presença de dois canais radiculares, enquanto nos demais grupos prevaleceu apenas um canal radicular.

Intentional Replantation of an Avulsed Immature Permanent Incisor: A Case Report.

This case report discusses the successful endodontic treatment of an open apex maxillary right permanent central incisor that had been avulsed and incorrectly replanted in a 7-year-old patient. The tooth was carefully re-extracted followed by cleaning of the alveolar socket and immediate replantation. However, pulp necrosis was diagnosed, and regenerative endodontic treatment was performed. The root canal system was disinfected by passive ultrasonic irrigation with 2.5% sodium hypochlorite. At the first visit, the tooth was repositioned and immobilized with an appropriate semirigid splint. After 14 days, the splint was removed, and the diagnosis of pulp necrosis was confirmed by thermal testing. The root canal was emptied, disinfected, and filled with calcium hydroxide paste, which was left in place for 7 days. At the third visit, calcium hydroxide was removed with hand files and passive ultrasonic irrigation, and the canal was filled with a mixture of double antibiotic paste (metronidazole/ciprofloxacin) and zinc oxide. The antibiotic paste was left in place for 30 days. At the final visit, the paste was removed and the periapical area stimulated with a #80 K-file to encourage clot formation within the pulp cavity. A mineral trioxide aggregate paste cervical plug was placed, and the tooth was restored with glass ionomer cement. Clinical and imaging (radiographic and tomographic) follow-up at 3, 6, 12, and 36 months showed endodontic success with continued root formation.

Influence of reuse and cervical preflaring on the fracture strength of reciprocating instruments.

OBJECTIVE: This study sought to assess the influence of cervical preflaring and reuse after resterilization, on fracture strength and plastic deformation and/or surface cracking in reciprocating nickel-titanium [NiTi] endodontic instruments after root canal instrumentation of extracted human teeth. MATERIALS AND METHODS: Forty engine-driven reciprocating NiTi instruments (20 Reciproc® [RC], VDW; 20 WaveOne® [WO], Dentsply) were used in root canal instrumentation of extracted human molars. A total of 485 human upper molars with similar anatomical features were selected and randomly distributed across four groups according to the instrumentation procedures performed (G1 and G3: RC; G2 and G4: WO). Reciprocating instruments were used as per manufacturer instructions. In groups G3 and G4, cervical preflaring was performed prior to instrumentation. After each use of each instrument, sterilization was repeated and scanning electron microscope (SEM) images were obtained to check for plastic deformations and/or cracks on instrument surfaces. Each instrument was used repeatedly until fracture occurred. RESULTS: Regardless of flaring, RC files exhibited greater fracture strength than WO instruments (P <0.01) with and without preflaring. Cervical preflaring significantly reduced the risk of instrument fracture (P <0.01). No plastic deformations were observed before fracturing. However, cracks were found on WO instruments shortly after their first use. RC and WO instruments resisted fracturing after autoclave sterilization. CONCLUSIONS: Cervical preflaring allowed a significant increase in the number of times RC and WO files could be reused safely.

Avaliação da descontaminação de cones de guta-percha usando diferentes métodos de desinfecção / Evaluation of gutta-percha points decontamination through different disinfection methods

A suscetibilidade ao crescimento bacteriano em cones de guta-percha (GP) e a forma de descontaminação desses cones usando quatro diferentes substâncias químicas foram avaliadas. Seis cones de GP foram selecionados de um ambiente clínico e levados com pinça estéril para um meio de cultura de Brain Heart Infusion (BHI), para avaliação de crescimento bacteriano. Outros doze cones foram divididos em quatro grupos experimentais de três cones, sendo: Grupo 1, hipoclorito de sódio a 2,5%; Grupo 2, álcool a 70%; Grupo 3, clorexidina gel a 2%; e Grupo 4, clorexidina líquida a 0,12%, onde cada cone ficou submerso na substância por um minuto, foi seco por meio de esfregaço com gaze estéril e inserido em meio de cultura BHI, para se avaliar a presença ou não de contaminação. Os resultados encontrados mostraram que os cones de guta-percha não apresentavam contaminação, independentemente de serem submetidos ou não a um processo de descontaminação. Dessa forma, conclui-se que não há necessidade de descontaminação dos cones de guta-percha, contanto que seja respeitada a cadeia asséptica do tratamento endodôntico.

Cyclic fatigue resistance of different continuous rotation and reciprocating endodontic systems.

OBJECTIVE: The objective of this study is to compare the cyclic fatigue resistance of nine types of endodontic instruments of nickel-titanium. MATERIALS AND METHODS: Five files of 25 mm of length of each group: Reciproc (RC) R25; WaveOne (WO) Primary; Unicone (UC) L25 25/0.06; K3XF 25/0.06; ProTaper Universal F2 (PTF2); ProTaper Next X2 (PTX2); Mtwo 25/0.06; BioRaCe 25/0.06; One Shape L25 25/0.06 were subjected to a cyclic fatigue resistance test on a mechanical apparatus. The mean fracture time was analyzed statistically by one-way analysis of variance and Tukey's honest significant difference post hoc test, with significance set at P< 0.05. CONCLUSION: It was observed that the groups PTX2, RC, R25, UC L25 25/0.06, and WO Primary presented greater cyclic fracture resistance than the other groups (P< 0.001).

Accuracy evaluation of three electronic apex locators in teeth with immature apices

Introduction and Objective: The aim of this randomized controlled study was to evaluate the accuracy of Root ZX, iPex and YS-RZ-A apex locators in tooth with incomplete apices. Material and methods: Thirty human mandibular pre-molars without dental caries, fracture and with 1-3mm apical diameter and ¾ of root development stage were used. After coronal access, tooth length was determined with the visualization of a K-file, compatible with the root canal diameter, at the apex. To determine the root canal length using electronic methods, the teeth were included in alginate. The 30 teeth were measured with the three apex locators until achieving the apex foramen. During the measurement, the canals were inundated with 1% sodium hypochlorite. Statistical analysis was performed using Qui-square test (p < 0.05). Results: The Root ZX apex locator showed the higher accuracy (53.3%), with statistical difference in relation to iPex apex locator (33.3%) and YS-RZ-A apex locator (26.7%) (p < 0.05). Regarding the security limit of ±1 mm, the Root ZX apex locator did not show statistical difference in comparison with iPex apex locator (p > 0.05), but both were statistically different in relation to YS-RZ-A apex locator (p < 0.05). Conclusion: The results showed that all the studied apex locators were efficient in determining the root canal length in tooth with incomplete apex, considering the tolerance of ±1 mm. The Root ZX apex locator showed the highest accuracy with 100% of agreement.

Prevalência de lesão endodôntica em pacientes diabéticos / Prevalence of apical periodontitis in diabetic patients / Prevalencia de lesión endodóntica de pacientes diabéticos

Investigar a prevalência de lesões endodônticas em pacientes diabéticos e não diabéticos. Métodos: Em estudo transversal, exames radiográficos (panorâmica e seriografia) de 80 pacientes, sendo 40 diabéticos tipo II e 40 não diabéticos, receberam avaliação, por meio de um índice de escores periapicais, das regiões perioendodônticas de todos os elementos dentais presentes. Os dados foram analisados pelo programa BioEstat 5.3®. Resultados: Encontrou-se pelo menos 1 dente apresentando lesão apical em 90% (n=32) dos pacientes diabéticos e 52% (n=21) dos pacientes não diabéticos (p=0,0001). Quanto aos dentes tratados endodonticamente, nos pacientes diabéticos, foram encontrados 44% (n=51) com lesões endodônticas, e apenas 17% (n=17) (p=0,0004) no grupo controle. Os pacientes diabéticos apresentaram maior quantidade de lesões endodônticas em relação aos pacientes não diabéticos (p=0,0189). Conclusão: De acordo com esses resultados, podese concluir que a Diabetes Mellitus tipo II está associada ao aumento da prevalência de lesões endodônticas...

To investigate the prevalence of apical periodontitis (AP) in diabetic and nondiabetic patients. Methods: Cross-sectional study, in which the radiographic records (panoramic and full-mouth periapical radiographs) of 80 patients, being 40 type II diabetic patients and 40 nondiabetic subjects, had the periapical and endodontic regions of all teeth present evaluated by means of the periapical index score. Data was analyzed through BioEstat 5.3TM software. Results: At least one tooth was found with apical periodontitis in 90% (n=32) of the diabetic patients and in 52% (n=21) of nondiabetic subjects (p=0.0001). Regarding root-filled teeth, 44% (n=51) presented AP amongst the diabetic patients, whereas only 17% (n=17) (p=0.0004) were affected in the control group. Conclusion: According to these results, type 2 Diabetes Mellitus is associated with an increase in the prevalence of apical periodontitis...

Investigar la prevalencia de lesiones endodónticas de pacientes diabéticos e no diabéticos. Métodos: Estudio transversal con pruebas radiológicas (panorâmica y seriografía) de 80 pacientes, siendo 40 diabéticos tipo II y 40 no diabéticos que recibieron evaluación a través del índice de puntuaciones periapicales de las regiones perioendodónticas de todos los elementos dentales presentes. Los datos fueron analizados con el programa BioEstat 5.3. Resultados: Se encontró por lo menos un diente con lesión apical en el 90% (n=32) de los pacientes diabéticos y el 52% (n=21) de los no diabéticos (p=0,0001). Respecto a los dientes tratados endodónticamente, el 44% (n=51) de los pacientes diabéticos presentó lesiones endodónticas y solamente el 17% (n=17) (p=0,0004) en el grupo control. Los pacientes diabéticos presentaron más lesiones endodónticas que los no diabéticos (p=0,0189). Conclusión: A partir de los resultados se concluye que la Diabetes Mellitus tipo II está asociada con el aumento de la prevalencia de lesiones endodónticas...

Two root canals in maxillary central incisor

Introduction and objective: The success of endodontic treatment requires the knowledge of tooth morphology and its variations. Case report: This clinical article reports an unusual root canal configuration that was detected in a maxillary central incisor with two root canals, demonstrated by radiographic and computerized tomography exams. Conclusion: Knowledge of endodontic anatomy as well as the obtainment of both preoperative radiographs and tomography is important to detect abnormal tooth morphology.

Evaluation of the dentin remaining after flaring using Gates Glidden drills and Protaper rotary files

INTRODUCTION: The application of rotary instruments for root canal preparation requires a safe, not harming procedure to the root structure remaining. OBJECTIVES: The purpose of this study was to analyze the root thickness in 28 mesial canals of lower permanent first molars before and after flaring using two rotary instruments: Gates-Glidden drills and ProTaper rotary files. MATERIAL AND METHODS: Teeth were embedded into a muffle system. Samples were obtained by cutting 2mm below the furcation. The images were captured by a digital video system (8X and 12X magnification). For image analysis and processing, Pro-Image Plus 4.1 software was used. Each image captured by the computer was gauged, eliminating any possible distortion. Gates-Glidden drills were used in decreasing order of size (GG#4, GG#3, GG#2). ProTaper was used according to the manufacturer's recommendations, with hand-piece powered by an electric motor with low torque. 5.25 percent sodium hypochlorite was utilized as irrigant. RESULTS: The average thickness between the canal and furcation before and after use of rotary instruments were: 0.857 mm and 0.561 mm for Gates-Glidden drills, and 0.858 mm and 0.486 mm for ProTaper, respectively. No statistical differences were found in the root thickness of specimens shaped with ProTaper rotary files and Gates Glidden drills. CONCLUSION: The use of Gates-Glidden drills is as safe as ProTaper rotary files with respect to danger of perforation on the distal side of the mesial roots of lower molars.

Análise da espessura da linha de cimento após o uso de diferentes técnicas de obturação de canais radiculares / Evaluation of the film thickness of a root canal sealer following different filling techniques

Introdução: O objetivo deste estudo foi realizar uma análise quantitativa da espessura da linha de cimento endodôntico formada após o uso de três diferentes técnicas de obturação. Materiais e método: Foram utilizados sessenta pré-molares inferiores. Após os procedimentos de limpeza e modelagem, os dentes foram distribuídos aleatoriamente em três grupos, de acordo com a técnica de obturação a ser empregada: Grupo I - Compressão hidráulica; Grupo II - Condensação lateral; Grupo III - Híbrida de Tagger. Foi utilizado no experimento um cimento a base de óxido de zinco eugenol. Os espécimes foram analisados em quatro cortes: 12 mm, 9 mm, 6 mm e 3 mm aquém do ápice radicular. As imagens dos cortes transversais foram capturadas e a espessura de cimento foi mensurada utilizando-se o programa Image Tool 3.0. A análise estatística foi executada utilizando-se o teste de Wilcoxon (SPSS 12.0). Resultados: A técnica de Tagger foi superior às demais, seguida pela compressão hidráulica e condensação lateral, com os resultados mostrarando-se estatisticamente diferentes entre todos os grupos (p = 0,0109). Conclusões: Em geral, as menores espessuras de cimento foram obtidas para o Grupo III, sendo piores os resultados obtidos para o grupo da condensação lateral.

Filling lateral canals: evaluation of different filling techniques.

OBJECTIVES: The purpose of this in vitro quantitative laboratorial study is to compare the ability of three filling techniques to fill simulated lateral canals. METHODS: Thirty extracted, single-rooted human teeth were used. After cleaning and shaping, three lateral canals were created, one in each third. The teeth were randomly separated into three groups: continuous wave of condensation (Group 1); thermomechanical compaction (Group 2); and lateral condensation (Group 3). The teeth were cross-sectioned, making the cut through points over the lateral canals; thus, 90 specimens were obtained. Each specimen was immersed in a polyester resin, and the blocks were polished. Images were obtained using a stereoscopic lens (40x). Radiographic analysis was performed, followed by a filling linear measure using the Image Tool 3.0 program (University of Texas). Data were statistically analyzed using SPSS 12.0 for Windows (Kruskal-Wallis test). RESULTS: A greater number of simulated lateral canals were obturated in Groups 1 and 2. Group 2 presented the largest percentage of linear measure of lateral canals filling with gutta-percha and sealer. No statistical differences were found between Group 1 and Group 2 when we analyzed the filling with gutta-percha and sealer or just sealer (P>.05). CONCLUSIONS: Thermoplasticized gutta-percha filling techniques (Groups 1 and 2) are better for filling lateral canal with gutta-percha and sealer or with just sealer than lateral condensation (Group 3).

Ex vivo evaluation of coronal and apical microbial leakage of root canal--filled with gutta-percha or Resilon/Epiphany root canal filling material.

OBJECTIVE: This ex vivo study compared coronal and apical microleakage of root canals filled with Resilon/Epiphany (RE) or gutta-percha/Grossman sealer (GP), using either lateral condensation (LC) or System B (SB) technique. MATERIALS AND METHODS: Specimens in eight experimental groups were obturated using the following materials and techniques: Groups 1 and 3--GP and LC; groups 2 and 4--GP and SB; groups 5 and 7--RE and LC; groups 6 and 8--RE and SB. Apical and coronal leakages were tested using bacterial methods. For coronal analysis, the number of days required for complete contamination of the root canals was recorded according to observation of the brain heart infusion broth turbidity for 15 weeks. For apical analysis, the teeth were cleaved and the leakage was measured at 30 days. Data were collected for each sample and analyzed statistically with the Chi-square and ANOVA tests. RESULTS: Leakage was found in all groups. The difference between filling materials, obturation techniques, and median time of leakage was not statistically significant for coronal ( P=0.847) and apical ( P=0.5789) leakages. CONCLUSION: There were no differences between the different filling materials (gutta-percha/Grossman sealer and Resilon/Epiphany) and obturation techniques (lateral condensation and system B technique) in coronal or apical leakages.

Six root canals in maxillary first molar.

In this clinical article we report an unusual anatomy that was detected in a maxillary first molar with 6 root canals. The possibility of 6 root canals in this tooth is quite small; however, it must be taken into account in clinical and radiographic evaluation during endodontic treatment. Many times their presence is noticed only after canal treatment, owing to continuing postoperative discomfort.

Clinical evaluation of the use of three anesthetics in endodontics.

This study compared three anesthetics widely used in endodontics and analyzed the following variables: amount necessary to achieve adequate anesthesia; anesthetic efficacy, defined as no sensation during endodontic treatment; anesthetic duration; and cost-benefit. Sixty patients diagnosed with irreversible pulpitis of a mandibular molar were selected at the Dental Emergency Center of Universidade de Fortaleza, Brazil. Patients were randomly divided into three groups of 20 and were administered one of three anesthetic solutions for conventional regional block: 2% lidocaine with 1:2500 phenylephrine; 2% mepivacaine with 1:100,000 adrenaline and 4% articaine with 1:100,000 epinephrine. The following variables were studied: number of cartridges necessary to obtain anesthetic success; anesthetic efficacy, defined as no sensation during endodontic procedures; anesthetic duration; cost-benefit ratio for each anesthetic. Mean number of cartridges necessary to obtain anesthetic success was 2.76, and there was no statistically significant difference between the anesthetics used. Lidocaine had the best cost-benefit ratio. All anesthetics used were clinically efficient and had equivalent results for endodontic treatment.

Three root canals in the maxillary second premolar.

In this study, we report an endodontic treatment of the maxillary second premolar with three root canals and distinct foramens. The possibility of three root canals in this tooth is quite small; however, it must be taken into account in clinical and radiographic evaluation during endodontic treatment. Many times, their presence is noticed only after canal treatment due to continuing post-operative discomfort.

Unusual anatomy of maxillary second premolars.

In this study, endodontic treatments of maxillary second premolars with unusual anatomical configuration were presented. Maxillary second premolars usually have one root with one or two root canals. The occurrence of variations in anatomical configuration is also common; therefore, it must be taken into account in clinical and radiographic evaluation during the endodontic treatment. These teeth may also require special shaping and filling techniques. This article reports and discusses the treatment recommendations for unusual occurrences of anatomical configurations in four different maxillary second premolars.

A case of unusual anatomy in second mandibular molar with four canals.

Success in root canal treatment is achieved after thought cleaning and shaping followed by the complete obturation of root canal system. Such treatment may be performed in root canal systems that do not comply with the normal anatomical features described in standard textbooks. This article describes the conventional root canal treatment on an unusual mandibular second molar with four root-canals.

Two palatal root canals in a maxillary second molar.

In this study, we report a case of two palatal root canals in a maxillary second molar that was endodontically treated. The possibility of two palatal root canals in maxillary second molars is quite small; however, it must be taken into account in clinical and radiographic evaluation during endodontic treatment. Often, their presence is noticed only after a canal treatment due to continuing post-operative discomfort.