Dynamic Cyclic Fatigue Resistance of Heat-treated Nickel Titanium Instruments in Reciprocating Motion.

OBJECTIVE: To compare the fatigue resistance of different heat-treated reciprocating instruments tested in a dynamic cyclic fatigue model. METHODS: Forty-eight new instruments were inspected under magnification and selected for this study, and then divided as follows (n=12): X1 Blue (MK Life, Porto Alegre, RS, Brazil), Pro-R (MK Life), Reciproc (VDW, Munich, Germany), and Reciproc Blue (VDW). Artificial canals presenting a curvature of 60° angle and 5 mm radius were milled in zirconia. The block containing the artificial canals was mounted in a container filled with water kept at 37°C. A specially designed device was used to perform controlled axial movements while the instruments were activated inside the canals. Time to failure was recorded in seconds, and fragment lengths were measured (mm). Data were analyzed statistically with the significance level set at 5% (One-Way ANOVA and Tukey test). RESULTS: Pro-R and Reciproc Blue instruments presented the highest fatigue resistance, being significantly different from the other tested files (p<0.05). Reciproc presented intermediate results, significantly different X1 Blue (p<0.05). The fractographic analysis showed typical features of cyclic fatigue for all instruments. CONCLUSION: Pro-R and Reciproc Blue instruments are more resistant to dynamic cyclic fatigue than the Reciproc and X1 Blue. (EEJ-2022-10-124).

Produtividade dos estudantes de Odontologia na clínica integrada em duas universidades do Sul do Brasil / Productividad de los estudiantes de Odontología en la clínica integrada en dos universidades del sur de Brasil / Productivity of dental students in integrated clinics attwo universities in Southern Brazil

Este estudo avaliou e comparou a produtividade clínica dos estudantes de Odontologia em duas instituições de ensino privadas, com diferentes tempos de experiência no modelo de clínica integrada, preconizado pelas Diretrizes Curriculares Nacionais (DCN). Asuniversidades utilizam o modelo de clínica integrada desde 2001 [A] e 2009 [B], com cursos de graduação de 5 anos e 4 anos, respectivamente. O estudo foi realizado no período de fevereiro a dezembro de 2019. Foram incluídos dados relativos a 205 estudantes (56 da universidade [A] e 149 da [B]) matriculados nas clínicas de baixa/média (n=99) e alta complexidades (n=106). Avaliou-se a quantidade de procedimentos realizados por nível de complexidade nas duas instituições. Os dados foram submetidos aos testes de Mann-Whitney e qui-quadrado (α=0,05). O número de procedimentos analisados foi de 9706, sendo 4693 na instituição [A] e 5013 na [B]. Nas duas instituições a quantidade de procedimentos curativos (54,8%) foi significativamente maior que a de procedimentos de diagnóstico e atenção à saúde (45,2%) (p<0,001). Nas clínicas de baixa/média complexidade foram observadas diferenças estatísticas na quantidade de procedimentos e/ou na quantidade de estudantes que não realizaram determinados procedimentos clínicos. Nas clínicas de alta complexidade foram observadas diferenças estatísticas entre as instituições na quantidade de procedimentos e/ou na quantidade de alunos que não realizaram determinados procedimentos específicos de Dentística, Cirurgia, Periodontia e Prótese. A instituição com maior tempo de experiência no modelo de clínica integrada apresentou melhores resultados nas especialidades de Dentística, Endodontia e Prótese (AU).

Este estudio evaluó y comparó la productividad clínica de estudiantes de odontología de dos instituciones de enseñanza privadas, con diferentes tiempos de experiencia en el modelo clínico integrado, recomendado por las Directrices Curriculares Nacionales (DCN). Las universidades han utilizado el modelo clínico integrado desde 2001 [A] y 2009 [B], con carreras de grado de 5 y 4 años, respectivamente. El estudio se realizó de febrero a diciembre de 2019. Se incluyeron datos de 205 estudiantes (56 de la universidad [A] y 149 de la [B]) matriculados en clínicas de baja/media (n=99) y alta complejidad (n=99) n=106). Se evaluó el número de procedimientos realizados por nivel de complejidad en ambas instituciones. Los datos fueron sometidos a las pruebas de Mann-Whitney y chi-cuadrado (α=0,05). Elnúmero de procedimientos analizados fue de 9706, 4693 en la institución [A] y 5013 en la [B]. En ambas instituciones, el número de procedimientos curativos (54,8%) fue significativamente superior al de procedimientos diagnósticos y asistenciales (45,2%) (p<0,001). En las clínicas de baja/media complejidad se observaron diferencias estadísticas en el número de procedimientos y/o en el número de alumnos que no se sometieron a determinados procedimientos clínicos. En las clínicas de alta complejidad se observaron diferencias estadísticas entre las instituciones en cuanto al número de procedimientos y/o el número de alumnos que no se sometieron a determinados procedimientos en Odontología, Cirugía, Periodoncia y Prótesis. La institución con mayor experiencia enel modelo de clínica integrada presentó mejores resultados en las especialidades de Odontología, Endodoncia y Prótesis (AU).

This study assessed and compared the clinical productivity of dental students in two private teaching institutions, with different lengths of experience in the integrated clinical model, recommended by the National Curriculum Guidelines (DCN). The universities have used the integrated clinical model since 2001 [A] and 2009 [B], with 5-year and 4-year undergraduate courses, respectively. The study was carried out from February to December 2019. Data were included for 205 students (56 from [A] and 149 from [B]) enrolled in low/medium (n=99) and high complexity clinics (n=106). The number of procedures performed by level of complexity in both institutions was assessed. Data were submitted to Mann-Whitney and chi-square tests (α=0.05). The number of procedures analyzed was 9706, 4693 in institution [A] and 5013 in [B]. In both institutions, the number of curative procedures (54.8%) was significantly higher than that of diagnostic and health care procedures (45.2%)(p<0.001). In low/medium complexity clinics, statistical differences were observed in the number of procedures and/or in the number of students who did not perform certain clinical procedures. In high-complexity clinics, statistical differences were observed between the institutions in terms of the number of procedures and/or the number of students who did not perform certain specific procedures in restorative dentistry, surgery, periodontics and prostheses. The institution with the longer experience in the integrated clinic model presented better results in the specialties of restorative dentistry, endodontics and prosthesis (AU).

Periapical Lesions Associated with Demographic Variables, Dental Conditions, Systemic Diseases, and Habits.

AIM AND BACKGROUND: The aim of this study was to analyze the prevalence of periapical lesions and possible associations with demographic, dental conditions, systemic diseases, and habit variables in patients from a private Brazilian university. MATERIALS AND METHODS: Data from 452 patients of both sexes, aged 18-78 years, from a Brazilian university were evaluated. Panoramic radiographs were analyzed, and the presence of periapical lesions was recorded. In these cases, the dental condition was assessed for the presence or absence of endodontic treatment. Medical records provide information related to general health (diabetes, cardiovascular diseases, altered cholesterol, autoimmune diseases, gallstones, or kidney stones) and habits (smoking or alcoholism). The data were descriptively analyzed, and then logistic regression and the Wald test were performed in Stata/SE v.14.1. RESULTS: A rate of 58.4% of participants were women, and the mean age was 36.4 (±14.6) years. Periapical lesions prevailed in 193 (42.7%) patients, and 281 (72.4%) teeth were not previously endodontically treated. Mandibular first molars (19%) and men (48.9%) were the most affected. The adjusted model showed that the age group of 26-45 years was 5 times more likely [odds ratio (OR) = 5.01; 95% confidence interval (CI): 2.85-8.82] to have lesions than those aged ≤25 years. Participants aged above 46 years were 19.1 times more prone (OR = 19.1; 95% CI: 10.2-36.0) to morbidity than younger ones (≤25 years). CONCLUSION: The studied sample showed that periapical lesions were more prevalent in males, in mandibular molars, and without prior endodontic treatment. There was no observed association between periapical lesions and comorbidities or habits; however, a significant correlation occurred with advancing age. CLINICAL SIGNIFICANCE: Comorbidities and habits were not associated with the presence of periapical lesions. However, aging has been identified as a significant risk factor for the development of periapical lesions. This finding is clinically relevant as it highlights the importance of monitoring and maintaining oral health in patients with advanced age. How to cite this article: dos Santos VC, de Oliveira Kublitski PM, Marques da Silva B, et al. Periapical Lesions Associated with Demographic Variables, Dental Conditions, Systemic Diseases, and Habits. J Contemp Dent Pract 2023;24(11):864-870.

Cleaning of long oval canals with WaveOne Gold system associated with different irrigant agitation protocols

Aim: The aim of the study was to evaluate the cleaning of mandibular incisors with WaveOne Gold® (WO) under different preparation techniques. Methods: A total of 210 human mandibular incisors were selected and divided into seven groups (n = 30), prepared by WO single-files (Small 20/.07 ­ WOS; Primary 25/.07 ­ WOP; Medium 35/.06 ­ WOM; or Large 45/.05 - WOL) and sequential-file techniques (WOS to WOP; WOS to WOM; and WOS to WOL). Further subdivision was made according to irrigation protocol: control group (manual irrigation - CON), E1 Irrisonic® - EIR, and EDDY® - EDD. Debris removal and the smear layer were evaluated by scanning electron microscopy. Data were analyzed by using Spearman's correlation test. The significance level was set at 5%. Results: For debris and smear layer removal, WOS and WOP, EIR differed from CON and EDD (p <0.05). Conclusion: Regardless of the instrumentation used, the agitation of the irrigant solution provided better cleanability. These findings reinforce the need for agitation techniques as adjuvants in cleaning root canal systems in mandibular incisors

Influence of different reciprocating systems on the apical extrusion of debris in flat-oval canals

Aim: To evaluate the apical extrusion of debris in flat-oval canals, using three reciprocating systems at two different working lengths (WL), 0 mm and 1 mm from the apical foramen. Methods: Ninety mandibular incisors were randomly divided into three groups based on the systems: WaveOne Gold #25.07 (WOG), ProDesign R #25.06 (PDR), and X1 Blue #25.06 (X1B). Extruded debris were collected and dried in pre-weighed Eppendorf tubes. Three consecutive weighings were performed for each tube, and the mean was calculated. If the assumptions of normality and homogeneity of variance were not met, the Kruskal-Wallis test was used to analyze the amount of extruded debris between groups with the same WL, and the Mann-Whitney U test was used for comparison within groups for each WL. Results: All groups had extruded debris, with higher median values occurring at 1 mm. No significant difference regarding the amount of debris extrusion was observed at 0 mm (p>0.05) and 1 mm (p>0.05) between groups. However, within the groups, at different WL, there was greater extrusion at 1 mm (p<0.05), with PDR differing significantly from the other systems (p<0.05). Conclusion: The extrusion of debris occurred regardless of the group, with higher values at 1 mm. However, using PDR at 1 mm from the apical foramen showed the highest values of extrusion

Postoperative Pain after Endodontic Treatment under Irrigation with 8.25% Sodium Hypochlorite and Other Solutions: A Randomized Clinical Trial.

INTRODUCTION: The aim of this study was to evaluate the postoperative pain in patients after endodontic treatment using 8.25% sodium hypochlorite (NaOCl) compared with other concentrations and 2% chlorhexidine (CHX). METHODS: In this double-blind randomized trial, 180 patients were evaluated who underwent a single session of endodontic treatment under irrigation with 2.5%, 5.25%, or 8.25% NaOCl or 2% CHX solutions. The presence of postoperative pain was assessed 24, 48, and 72 hours after treatment and recorded using the visual analog scale (VAS). A descriptive analysis, logistic regression, and Wald test were performed. RESULTS: Altogether 169 patients participated, of whom 107 were women, and the mean age was 38.1 ± 14.4 years. No significant differences occurred between the irrigants and the pain outcomes, not even for the use of postoperative pain medication and responses to VAS (P > .05). In the multivariate model including irrigants, after 24 hours or at any time, a significant difference (P < .05) remained in preparation time ≥10 minutes and the presence of overfilling. Also, in relation to the VAS, the overfilling presented significantly different results (P < .05). CONCLUSIONS: There was no significant difference in the presence of postoperative pain between the 8.25% NaOCl and the other irrigation solutions. However, the extended preparation time and the overfilling material were responsible for the increase of postoperative pain.

Descoloração da coroa após obturação endodôntica com diferentes cimentos: estudo clínico / Crown discoloration after endodontic obturation with different cements: a clinical study

Objetivo: O objetivo do presente estudo foi avaliar clinicamente a descoloração da coroa dentária após obturação do canal radicular com diferentes cimentos endodônticos. Métodos: Trinta e dois dentes foram tratados endodonticamente e obturados com AH Plus (AHP), Endofill (END), MTA Fillapex (MTA) ou Sealer 26 (SEA), divididos em oito pacientes por grupo. O registro das cores foi realizado com um espectrofotômetro antes da intervenção (T0 ), aos 30 (T1 ) e aos 90 dias após a intervenção (T2 ). As avaliações foram feitas no centro da coroa dentária e a variação de cor (ΔE) foi calculada por meio da Commission International de l'Eclai- rage (CIE) L*a*b. Um operador, especialista em Endodontia, realizou os procedimentos clínicos. Os dados foram submetidos a medidas repetidas ANOVA e teste de Tukey (Δ=5%). Resultados: Não houve diferença estatisticamente significativa na variação de cores entre os cimentos (AHP ΔE=4,11; END ΔE = 6,34; SEA ΔE = 8,77 e MTA ΔE = 12,15), p>0,05. Porém, houve diferença entre os períodos analisados (T1ΔE= 5,65; T2 ΔE = 10,02). Conclusões: Dentro das limitações deste estudo, todos os cimentos endodônticos causaram alterações cromáticas clinicamente perceptíveis na coroa dentária. No entanto, o AH Plus promoveu menos alterações cromáticas na coroa dentária (AU).

Introduction: The aim of this study was to evaluate the crown discoloration after root canal filling with different endodontic cements clinically. Methods: Thirty-two teeth were endodontically treated and filled with AH Plus (AHP), Endofill (END), MTA Fillapex (MTA), or Sealer 26 (SEA), divided into eight patients per group. Color recording was performed with a spectrophotometer before the intervention (T0 ) and at 30 (T1 ) and 90 days post-intervention (T2 ). The evaluations were done in the center of the dental crown and color variation (ΔE) was calculated by means of the Commission International de IEclairage (CIE) L*a*b. The data were subjected to repeated measures ANOVA and Tukeys test (alpha=5%). Results: There was no statistically significant difference in color variation between the cements (AHP ΔE=4.11; END ΔE=6.34; SEA ΔE=8.77, and MTA ΔE=12.15), p>0.05. However, there was a difference between the periods tested (T1 ΔE=5.65; T2 ΔE=10.02). Conclusions: All tested endodontic cements altered the color of dental crowns (AU).

Effects of 1-Ethyl-3-(3-Dimethylaminopropyl) Carbodiimide on Adhesion of Posts in Teeth Obturated With Different Sealers.

The aim of this study was to evaluate the effect of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) on bond strength of fiberglass posts in root canals obturated with different endodontic sealers. Seventy-eight mandibular premolars were obturated with three sealers (n=26): Endofill (END), AH Plus (AHP), and Endosequence BC Sealer (EBS). After preparation of the post space, two subgroups were formed according to the cementation of the posts (n=13): with EDC (EDC), and without EDC (control - CON). The specimens were submitted to a pull-out test, failure mode classification, and root canal surface evaluation by scanning electron microscopy after post displacement. Regarding the bond strength, a significant difference between the EDC and CON subgroups occurred only in the END (p=0.001). No difference was detected among the CON subgroups (p=0.339). However, among the EDC subgroups, AHP presented significantly higher values (END versus AHP: p=0.001; AHP versus EBS: p=0.016). Upon classification of failure modes, score 1 (≥ 50% of cement) was the most commonly observed, except for the END + EDC. Remains of endodontic sealers and resin cements were found in the cervical third, but without statistical difference (p=0.269), while in the middle third, difference occurred (p=0.004). In conclusion, EDC decreases bond strength when associated with END sealer, without changing the failure mode between the resin cement and fiberglass post. The best performance was observed when EDC was combined with AHP sealer.

Comparison of Canal Transportation and Centering Ability of ProGlider and WaveOne Gold Glider in Curved Canals.

OBJECTIVES: The aim of this study was to compare the volume variation and maintenance of the root canal position when using the ProGlider 16.02 (PG) and the WaveOne Gold Glider 15.02 (WOGG) file systems for glide path preparation. MATERIALS AND METHODS: Twenty-four moderately curved mesiobuccal canals of maxil-lary first molars were selected and randomly divided into two groups: PG and WOGG. The selected teeth were scanned using microtomography before and after root canal preparation to assess centralization and linear transport at 1, 3, 5, and 7 mm from the apical foramen. STATISTICAL ANALYSIS: The data were analyzed with the Mann-Whitney U test. The level of significance was 5%. RESULTS: There were no significant differences in volume variation or root canal transport (p > 0.05). There was a significant difference in the centralization of the root canal at 3 mm from the foramen (p < 0.05). CONCLUSIONS: WOGG and PG instruments presented similar results regarding the root canal volume increase and transport. WOGG caused higher decentralization at 3 mm from the apical foramen.

Effects of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide on adhesion of posts in teeth obturated with different sealers

Abstract The aim of this study was to evaluate the effect of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) on bond strength of fiberglass posts in root canals obturated with different endodontic sealers. Seventy-eight mandibular premolars were obturated with three sealers (n=26): Endofill (END), AH Plus (AHP), and Endosequence BC Sealer (EBS). After preparation of the post space, two subgroups were formed according to the cementation of the posts (n=13): with EDC (EDC), and without EDC (control - CON). The specimens were submitted to a pull-out test, failure mode classification, and root canal surface evaluation by scanning electron microscopy after post displacement. Regarding the bond strength, a significant difference between the EDC and CON subgroups occurred only in the END (p=0.001). No difference was detected among the CON subgroups (p=0.339). However, among the EDC subgroups, AHP presented significantly higher values (END versus AHP: p=0.001; AHP versus EBS: p=0.016). Upon classification of failure modes, score 1 (≥ 50% of cement) was the most commonly observed, except for the END + EDC. Remains of endodontic sealers and resin cements were found in the cervical third, but without statistical difference (p=0.269), while in the middle third, difference occurred (p=0.004). In conclusion, EDC decreases bond strength when associated with END sealer, without changing the failure mode between the resin cement and fiberglass post. The best performance was observed when EDC was combined with AHP sealer.

Resumo O objetivo deste estudo foi avaliar o efeito da 1-etil-3- (3-dimetilaminopropil) carbodiimida (EDC) na resistência de união de pinos de fibra de vidro em canais radiculares obturados com diferentes cimentos endodônticos. Setenta e oito pré-molares inferiores foram obturados com três cimentos endodônticos (n=26): Endofill (END), AH Plus (AHP) e Endosequence BC Sealer (EBS). Após o preparo do espaço para pino, dois subgrupos formaram-se conforme a cimentação dos pinos (n=13): com EDC e sem EDC (controle - CON). Os espécimes foram submetidos ao teste pull-out, classificação do modo de falha e avaliação da superfície do canal radicular por microscopia eletrônica de varredura após o deslocamento. Quanto à força de resistência de união, uma diferença estatisticamente significativa ocorreu entre os subgrupos EDC e CON apenas no END (p=0,001). Não foi detectada diferença entre os subgrupos CON (p=0,339). Contudo, no subgrupo EDC, o AHP apresentou maiores valores (END versus AHP: p=0,001; AHP versus EBS: p=0,016). Acerca da classificação dos modos de falha, o escore 1 (≥50% de cimento) foi o mais comumente observado, exceto para END + EDC. Restos de cimentos endodônticos e cimentos resinosos foram encontrados no terço cervical, mas sem diferença estatística (p=0,269), enquanto no terço médio, houve diferença (p=0,004). Em conclusão, o EDC diminui a resistência de união quando associado ao cimento END, sem alterar o modo de falha entre o cimento resinoso e o pino de fibra de vidro. O melhor desempenho foi observado quanto o EDC foi usado com o cimento AHP.

Temperature changes affect the rheological properties of a silicone-based and an epoxy resin-based root canal sealers.

To evaluate temperature changes on the rheological properties (setting time and complex viscosity (η*)) of GuttaFlow Bioseal (GFB) and AH Plus Jet (AHPJ). Rheological measurements were performed in oscillating mode at the strain amplitude and angular frequency of 0.01% and 10 rad s-1 , respectively. Each sealer (n = 5) was tested running a temperature ramp (rapid increase to 80°C, 1 min constantly at 80°C, and slower decrease to 37°C). Control groups (n = 5) were tested at a constant temperature of 37°C. Kolmogorov-Smirnov and one-way ANOVA (P < 0.05) statistical tests were performed. The temperature ramp reduced setting time of GFB (24.85 to 4.45 min) (P < 0.05), but did not alter that of AHPJ (P > 0.05). GFB exhibited an increased η*, whereas the AHPJ η* was decreased when heated (P < 0.05). Rheological properties of sealers were negatively affected by temperature changes.

Influence of the Preparation Order in Four-Canal Maxillary Molars with WaveOne Gold System.

INTRODUCTION: The aim of this study was to evaluate the effect of the order of preparation of four-canal maxillary molars on volume variation, instrument deformation, cyclic fatigue, and preparation time by using the WaveOne Gold Primary (WOG 25.07). METHODS: We selected 48 permanent, human, four-canal maxillary molars. The teeth were divided into 4 groups according to the order of initiation of the canal preparation sequence: (1) mesiobuccal (MB), distobuccal (DB), palatal (P), second mesiobuccal (MB2); (2) DB-P-MB2-MB; (3) P-MB2-MB-DB and (4) MB2-MB-DB-P. Pre- and post-preparation microtomography scanning was performed to obtain initial and final canal volume measurements. The instruments were also evaluated by using scanning electron microscopy to determine the wear and deformation present after use. The active instrumentation time was also recorded. The data were statistically compared by using a significance level of 5%. RESULTS: No statistically significant difference was found between groups for volume variation and time of preparation of the canals with the WOG system (P > .05); however, a statistically significant difference was observed in the deformation of the instruments. In the comparison between the groups for MB-DB-P-MB2 and P-MB2-MB-DB, the latter presented greater deformation of the instruments. CONCLUSIONS: Root canal preparation sequence affected deformation of the instruments but did not influence the volume variation or the canal preparation time with the WOG system. To minimize instrument deformation, the preparation order should be MB-DB-P-MB2.

Effect of Vehicle and Agitation Methods on the Penetration of Calcium Hydroxide Paste in the Dentinal Tubules.

INTRODUCTION: The aim of this ex vivo study was to analyze the effect of different vehicles combined with agitation methods on the penetration of calcium hydroxide (CH) paste in the dentinal tubules. METHODS: Sixty freshly extracted, single-rooted human premolars were prepared using WaveOne Gold (Dentsply Sirona, York, PA) and randomized into 6 experimental groups (n = 10) according to the vehicle and method of paste agitation as follows: propylene glycol (PG) + Lentulo, PG + Lentulo + ultrasound, PG + Lentulo + sonic, distilled water (DW) + Lentulo, DW + Lentulo + ultrasonic, and DW + Lentulo + sonic. The CH paste was manipulated with sodium fluorescein dye and was inserted to completely fill the root canal. Two 1-mm thick sections at 2 mm and 5 mm from the apex of each root were obtained. The sections were scanned using confocal laser scanning microscopy, and the images were analyzed using ImageJ software (Bethesda, MD) to calculate the percentage penetration and maximum penetration depth of CH paste. Statistical analysis was performed using 1-way analysis of variance and Tukey honestly significant difference post hoc tests. RESULTS: No statistically significant differences between study factors at a distance of 2 mm from the apex were observed (P > .05). However, at 5 mm, a significant difference between the vehicles (P < .05) in percentage penetration was demonstrated with higher means for PG. CONCLUSIONS: Vehicles interfered with the penetration of CH in the dentinal tubules at 5 mm from the apex with better results for PG.

Influence of activation mode and preheating on intracanal irrigant temperature.

This ex vivo study assessed the effectiveness of two activation modes to increase the intracanal temperature of 5.25% NaOCl solution and the time for a preheated-irrigant to return to its initial temperature. Ten single-rooted extracted human teeth were used. Thermocouples were adapted to the root surface and the temperature was registered following two activation modes: ultrasound (US) and thermal. Furthermore, a preheated-solution (45°C/60°C) was flushed into root canal to test the time needed to return to its initial temperature. Data were analysed using two-way ANOVA and Tukey's post-hoc tests (P = 0.05). Statistical analysis showed differences between the activation modes. US and thermal activation increased from 37 to 40.4°C and to 62.8°C respectively in 60 s. Time for preheated-irrigant to return to its initial temperature was longer for 60°C. Preheating irrigant at 60°C and using thermal activation to keep it warm may represent a further step of the irrigation protocol.

Analysis of reciprocating system real-time torque variation during root canal preparation.

OBJECTIVE: This study monitored real-time torque variation of the WaveOne Gold (WOG) and Reciproc Blue (RB) during root canal preparation of mandibular molars. Thirty-six mandibular molars were prepared with WOG Primary 25.07 (WOGP, n = 36) and the RB R25 25.08 (RBR25, n = 36) for the mesial canals, whereas WOG Large 45.05 (WOGL, n = 18) and RB R40 40.06 (RBR40, n = 18) for the distal. Canal preparation was divided into thirds and the torque, maximum torque and time, were recorded. RESULTS: The RBR25 instruments exhibited higher maximum torque in the apical third in contrast to the WOGP instruments (p < 0.05). The intragroup analysis found a significant difference in maximum torque between the cervical and apical thirds, and the middle and apical thirds (p < 0.05) for both instruments (RBR25 and WOGP). The WOGP group had the shortest preparation time (p < 0.05). There were no significant differences between the WOGL and RBR40 for any of the parameters evaluated (p > 0.05). The RBR25 had the highest torque when compared to the WOGP. Both instruments exhibited higher torque in the apical third and there were no significant differences between the instruments in the distal canal.

Pesquisa científica em Endodontia apresentada na Reunião Anual da Sociedade Brasileira de Pesquisa Odontológica: análise bibliométrica de 2010 a 2018 / Scientific production in Endodontics at the Meeting of the Brazilian Society for Dental Research: bibliometric analysis from 2010 to 2018

A Reunião anual da Sociedade Brasileira de Pesquisa Odontológica (SBPqO) é um importante evento da produção científica odontológica no país. A avaliação do perfil dos trabalhos apresentados pode identificar características e a evolução da pesquisa em Endodontia. Por meio desta análise bibliométrica retrospectiva buscou-se investigar a produção científica na área de Endodontia nos suplementos das reuniões da SBPqO, de 2010 a 2018. Os suplementos foram acessados on-line, no sítio web da instituição, e os resumos foram analisados de acordo com a região de origem: Norte, Nordeste, Centro-Oeste, Sul e Sudeste; e categorias temáticas: Terapêutica, Anatomia, Biossegurança, Microbiologia, Citologia/Genética, Diagnóstico, Epidemiologia, Materiais, Técnicas, Instrumentos, Traumatismo e Desfecho clínico. Dos 22.310 resumos publicados no período, foram selecionados 2516 da área de Endodontia. No ano de 2010 houve o maior número de resumos publicados (n=375). Prevaleceram as pesquisas voltadas à análise de materiais (27,1%) e de técnicas (20,6%). As regiões Sudeste e Sul apresentaram frequências de resumos com valores de 65,5% e 17,2%, respectivamente, enquanto a menor participação foi da região Norte (2,5%). A frequência de pesquisas de Endodontia publicadas nos resumos dos suplementos da SBPqO se manteve equilibrada ao longo do período analisado, com destaque para objetivos focados em materiais e técnicas e maior produtividade das regiões Sudeste e Sul (AU).

The annual meeting of the Brazilian Society of Dental Research (Sociedade Brasileira de Pesquisa Odontológica - SBPqO) is an important event of dental scientific production in the country. The evaluation of the profile of the presented research can identify characteristics and the evolution of Endodontics research. Through retrospective bibliometric analysis, meeting supplements from 2010 to 2018 were investigated to determine the scientific production in the area of Endodontics in SBPqO. The supplements were accessed online, via the institution's website, and the abstracts were analyzed according to region of origin: North, Northeast, Midwest, South and Southeast; and thematic categories: Therapeutics, Anatomy, Biosafety, Microbiology, Cytology/Genetics, Diagnosis, Epidemiology, Materials, Techniques, Instruments, Trauma and Clinical Outcome. Of the 22,310 abstracts published in the period, 2516 were selected from the Endodontics area. In 2010 there was the largest number of published abstracts (n = 375). Prevailed the research focused on the analysis of materials (27.1%) and techniques (20.6%). The Southeast and South regions presented summary frequencies with values of 65.5% and 17.2%, respectively, while the lowest participation was from the North region (2.5%). The frequency of Endodontic research published in SBPqO supplement remained balanced over the analyzed period, with emphasis on objectives focused on materials and techniques, and higher productivity in the Southeast and South (AU).

Root Preparation of Deciduous Teeth: Efficacy of WaveOne and ProTaper Systems with and without Passive Ultrasonic Irrigation.

INTRODUCTION: The aim of this study was to compare root preparation of deciduous teeth with WaveOne Large (WO) and ProTaper F4 (PT) instruments with or without passive ultrasonic irrigation (PUI). METHODS AND MATERIALS: Forty-eight deciduous teeth were scanned before and after root preparation and divided in four groups (n=12): WO+EDTA (WO); WO+EDTA with PUI (WOPUI); PTF+EDTA (PT); and PT+EDTA with PUI (PTPUI). Root canal enlargement by micro-computed tomography and root canal cleaning by scanning electron microscopy (SEM) were analyzed. Data were submitted to two-way ANOVA and Tukey's tests to analyze the root canal volume variation, and Kruskal-Wallis followed by Friedman and Wilcoxon tests were used to evaluate the cleaning efficacy. The level of significance was set at 0.05. RESULTS: No significant difference occurred in total volume between groups (P>0.05). On analysis by thirds of the root canal, there was a difference in volume between WO (cervical) compared to WO and PT (apical), and PTPUI (middle and apical) (P<0.05). When cleaning of the thirds within the same group was compared, there was a significant difference in all groups (P<0.05). Among the groups, in the thirds, in the cervical a difference occurred (P=0.028), and the pairwise comparisons indicated statistically difference between WO and PT, and WO and PTPUI (P<0.05). In the pairwise comparisons among thirds, in the groups, difrences occured in all of them when compared the cervical and apical thirds (P<0.05). CONCLUSION: Passive ultrasonic irrigation has not improved the smear layer removal in deciduous teeth. Despite the differences in performance between WO and PT instruments, both were suitable for preparation of deciduous teeth.

Long-term evaluation of crown and root discoloration induced by different endodontic sealers

Aim: To evaluate crown and root discoloration promoted by different endodontic sealers after root canal filling. Methods: Eighty bovine incisors were prepared and filled with: Endofill, Sealer 26, AH Plus, and MTA Fillapex. Color was recorded using a spectrophotometer before endodontic treatment (T0) and at 24 hours (T1), seven days (T2), 30 days (T3), and 90 days (T4) after treatment. Analyses were performed on the middle and cervical regions of the crown, and on the cervical third of the root, immediately below the cementoenamel junction. The color alterations (ΔE) were calculated using Commission International de I'Eclairage (CIE) L*a*b parameters, and data were analyzed by analysis of variance (ANOVA) and Tukey's test (p<0.05). Results: All sealers induced color alterations. Sealer 26 resulted in the smallest changes in color (E = 5.32). The other materials did not present statistical differences (AH Plus E = 6.98; MTA Fillapex E = 6.88; Endofill E = 6.41). Of the three regions analyzed, the largest discoloration was observed at the cervical third of the root (E=10.67). In terms of time, the largest ΔE values (E=7.72) were observed at T4. Color changes at T1 (E=5.88), T2 (E=6.10), and T3 (E=5.89) were statistically similar. Conclusions: All endodontic sealers promoted discoloration on the tooth crown and root

Efficacy of Different Cone-beam Computed Tomographic Protocols in the Identification of Mesiobuccal Canals of Maxillary First Molars: A Tomographic and Ex Vivo Study.

INTRODUCTION: Complementary methods of anatomic diagnosis, including cone-beam computed tomographic (CBCT) imaging, may be useful in the diagnosis of mesiobuccal (MB) canals of maxillary molars. METHODS: Thirty-five maxillary first molars were subjected to ex vivo analysis and 4 CBCT protocols: i-CAT Classic (Imaging Sciences International, Hatfield, PA) (ICC group), i-CAT Next Generation (Imaging Sciences International) (ICN group), PreXion 3D (PreXion, San Mateo, CA) (16.8-second acquisition time; PX1 group), and PreXion 3D (33.5-second acquisition time; PX2 group). The images were evaluated by 2 calibrated endodontists who kept records following protocols previously published in the literature. Micro-computed tomographic imaging was used as the control. RESULTS: The correct identification of anatomic variations of MB roots was 54.3% (n = 19) in the ICC group, 65.7% (n = 23) in the ICN group, and 80.0% (n = 28) in the PX1 and PX2 groups. The probability of agreement between the ICC and the control groups was significantly different from the probability of agreement with the PX1 (P < .05) and PX2 (P < .05) groups. The other groups showed no significant differences compared with the control group. There was no difference in the probability of agreement between the tomographic protocols and the ex vivo results. CONCLUSIONS: The PX1 and PX2 groups were more effective for the diagnosis of MB canals. PX1 is the most suitable because it results in a shorter radiation time and diagnostic imaging similar to PX2. The single-canal anatomy was the most prevalent in the study.

Avaliação de métodos de manutenção da esterilidade do órgão dental humano extraído para armazenamento em banco de dentes / Evaluation of methods for maintaining sterility of the extracted human dental organ during storage in a tooth bank

A importância de um banco de dentes humanos em uma instituição de se justifica e se mostra vantajosa, uma vez que permite a máxima aproximação da realidade ao se trabalhar com o órgão extraído. Este estudo teve o propósito de avaliar métodos de manutenção da esterilidade do órgão dental humano extraído armazenado. Foram utilizados 72 dentes incisivos humanos extraídos, obtidos em clínicas de graduação e de pós-graduação da Universidade Positivo, Curitiba, PR, Brasil. Os elementos dentários foram cedidos pelos pacientes, por meio de termo de doação devidamente assinado. Após os procedimentos de limpeza e de desinfecção, 36 dentes foram esterilizados em autoclave e 36 foram somente limpos. Os dentes foram, então, armazenados em recipientes contendo o método (autoclavagem ou limpeza) ou a solução de escolha, por um período de 15 e 120 dias. Testes microbiológicos foram realizados a fim de determinar qual método ou solução de armazenamento promove a manutenção da esterilidade no tempo determinado. Melhores desempenhos foram observados quando as amostras foram armazenadas em Incidin Extra N®, formol e álcool, mesmo para os dentes não autoclavados. As substâncias em análise nos períodos propostos se mostraram capazes de impedir o crescimento microbiano. Este experimento poderá auxiliar o desenvolvimento de um protocolo de processamento e de administração do órgão dental humano extraído em um banco de dentes (AU).

The importance of a human teeth bank in an institution is justified and it is advantageous, since it allows the maximum approximation of reality when working with the extracted organ. This study aimed to evaluate methods for maintaining the sterility of extracted human teeth during storage. A total of 72 human incisors extracted in the undergraduate and graduate clinics of Universidade Positivo (Curitiba, PR, Brazil) were used in this study. The teeth were provided by patients, who signed a donation form. After all teeth were subjected to cleaning and disinfection procedures, 36 teeth were autoclaved as well. Teeth were then stored in various solutions for periods of 15 and 120 days. Microbiological tests were conducted to determine which method or storage promoted maintenance of sterility. Better results were obtained for teeth - including autoclaved teeth - stored in Incidin Extra N®, formaldehyde, and alcohol. The solutions analyzed over the proposed time periods have been shown to prevent microbial growth. Results of this study will aid in developing a protocol of processing for extracted human dental teeth to be stored in a tooth bank (AU).