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).

Influence of Filling Material Remnants on the Diffusion of Hydroxyl Ions in Endodontically Retreated Teeth: An Ex Vivo Study.

AIM: To assess the influence of remnants of filling material on hydroxyl ion diffusion from calcium hydroxide (CH) paste, measured by the pH value, in retreated teeth. MATERIALS AND METHODS: A total of 120 single-rooted extracted teeth were prepared up to a size 35 hand file and filled. For retreatment, the specimens were divided into four groups (n = 20): ProTaper Universal Retreatment (PUR), PUR with additional instrumentation (PURA), Mtwo Retreatment (MTWR), and MTWR with additional instrumentation (MTWRA). Negative (NEG) and positive (POS) control groups were composed by 20 specimens each one. The specimens, except NEG, were filled with CH paste. The retreated groups were scanned using cone-beam computed tomography (CBCT) for analysis of filling remnants. The pH assessment was performed at the baseline, after seven, 21, 45, and 60 days of immersion in saline. Data were analyzed using Shapiro-Wilk and Levene's test, followed by a two-way analysis of variance (ANOVA) and Tukey's test. RESULTS: Additional instrumentation (PURA and MTWRA) were superior regarding removal of the filling material (p <0.05); however, without significant difference (p >0.05). The mean pH value in all groups increased (p <0.05). After 60 days, no statistical difference was observed among POS and PURA; and MTWR and MTWRA. There was less diffusion of hydroxyl ions when the amount of remnants was greater than 59%. CONCLUSION: Additional instrumentation improved the ability to remove filling material in both systems. All groups presented increasing pH; however, the higher the amount of remnants, the lower the diffusion of hydroxyl ions. CLINICAL SIGNIFICANCE: The amount of remnants allows less diffusion of calcium hydroxyl ions. Thus, additional instrumentation improves the ability to remove these materials.

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

Educational approaches for assessing knowledge about and actions of educators in response to dental avulsion.

BACKGROUND: Dental trauma affects especially schoolchildren and adolescents. Educators, the responsible for the first appointment, have a fundamental role in the prognosis of dental avulsion that occurred in this environment. AIM: To evaluate the educational approaches for assessing knowledge and actions in response to dental avulsion among educators. SETTINGS AND DESIGN: This cross-sectional and quanti-qualitative study included 197 teachers and 24 pedagogical coordinators (PCs), from the public schools of Pato Branco, Paraná, Brazil. METHODS: A questionnaire was initially administered regarding the knowledge about avulsion to all participants. Teachers just read a manual and answered the questionnaire after 30 days. PCs were divided into (n = 12): G1 - manual + fictitious scenario of avulsion and G2 - active methodology + fictitious scenario. The questionnaire was re-administered to all. STATISTICAL ANALYSIS: Quantitative data were analyzed statistically. For the qualitative stage, two questions were proposed and the Bardin's analysis was performed. RESULTS: For teachers, knowledge about avulsion increased after the intervention (P < 0.001), except as related to cleaning the tooth (P = 0.21). Activities involving G1 and G2 also led to an increase in knowledge, but no difference occurred in this increase between the approaches (P = 0.14). Qualitative analysis highlighted the need for calm and for performing actions that could favor a good prognosis in cases of avulsion. CONCLUSIONS: The level of knowledge increased after interventions, but no significant differences between the educational approaches were found.

Endodontic Retreatment Using a Single Instrument from four Nickel-Titanium Systems - A Micro-CT Study.

This study evaluated the efficiency of using a single instrument from three different rotary multi-file systems and compared them with that of a reciprocating single-file for endodontic retreatment by means of micro-CT. Sixty extracted canines were prepared using a size F2 ProTaper Universal file and obturated. After 30 days of storage at 37ºC and 100% humidity, the teeth were randomly divided into four groups (n=15) based on the type of instrument used to retreatment: ProTaper Next (PTN), ProTaper Gold (PTG), TRUShape 3D (TS), and WaveOne (WO). The canals were retreated using only the size 40 instrument from each system according to the manufacturer's recommendations for torque and speed. The time required to remove the filling material was recorded in seconds. The amount of initial and residual filling material and the quantity of dentin removed were assessed by means of micro-CT. Data were statistically analyzed (ANOVA and Kruskal-Wallis) at a 5% significance level. TS instruments required the highest (p<0.05) amount of time (mean, 384.80 ±144.92) compared with the WO (229.67±68.16) and PTG (248.67±64.22) and not so different from PTN instruments (327.67±133.3). No differences in the amount of dentin removed, initial and residual filling volume, and percentages of filling material were observed among the groups. The use of a single rotary instrument from the PTG, TS, and PTN systems was as effective as that of the single-file reciprocating WO system. However, none of the instruments was able to remove the filling materials completely.

Endodontic retreatment using a single instrument from four nickel-titanium systems - a micro-ct study

Abstract This study evaluated the efficiency of using a single instrument from three different rotary multi-file systems and compared them with that of a reciprocating single-file for endodontic retreatment by means of micro-CT. Sixty extracted canines were prepared using a size F2 ProTaper Universal file and obturated. After 30 days of storage at 37ºC and 100% humidity, the teeth were randomly divided into four groups (n=15) based on the type of instrument used to retreatment: ProTaper Next (PTN), ProTaper Gold (PTG), TRUShape 3D (TS), and WaveOne (WO). The canals were retreated using only the size 40 instrument from each system according to the manufacturer's recommendations for torque and speed. The time required to remove the filling material was recorded in seconds. The amount of initial and residual filling material and the quantity of dentin removed were assessed by means of micro-CT. Data were statistically analyzed (ANOVA and Kruskal-Wallis) at a 5% significance level. TS instruments required the highest (p<0.05) amount of time (mean, 384.80 ±144.92) compared with the WO (229.67±68.16) and PTG (248.67±64.22) and not so different from PTN instruments (327.67±133.3). No differences in the amount of dentin removed, initial and residual filling volume, and percentages of filling material were observed among the groups. The use of a single rotary instrument from the PTG, TS, and PTN systems was as effective as that of the single-file reciprocating WO system. However, none of the instruments was able to remove the filling materials completely.

Resumo Este estudo laboratorial avaliou por meio de micro-CT a eficiência do uso de um único instrumento de três sistemas rotatórios em retratamentos endodônticos, comparados a um instrumento único reciprocante. Sessenta caninos extraídos foram preparados usando o sistema ProTaper Universal (F2) e obturados. Após 30 dias de armazenamento a 37 ºC e 100% de umidade, os dentes foram divididos aleatoriamente em quatro grupos (n = 15), de acordo com o instrumento utilizado para remover as obturações endodônticas: ProTaper NEXT (PTN), ProTaper Gold (PTG), TRUShape 3D (TS) e WaveOne (WO). Os canais foram retratados usando apenas o instrumento tamanho 40 de cada sistema, seguindo as recomendações do fabricante para torque e velocidade. O tempo necessário para remover a obturação foi registrado em segundos. A quantidade de material remanescente e o volume de dentina removida foram avaliadas por meio de micro-CT. Análise estatística foi realizada (ANOVA e Kruskal-Wallis), com nível de significância de 5%. O tempo de trabalho no grupo TS foi significativamente maior (p<0.05) (média, 384,80 ± 144,92) comparado a WO (229,67 ± 68,16) e PTG (248,67 ± 64,22), e similar a PTN (327,67 ± 133,3). Não houve diferenças entre os grupos na quantidade de dentina removida e nas porcentagens de material obturador residual. O uso de apenas um instrumento rotatório dos sistemas PTG, TS e PTN foi tão eficaz quanto o do sistema WO reciprocante na remoção do material obturador. No entanto, nenhum dos instrumentos conseguiu remover completamente os materiais obturadores.

Maintenance of Pulp after Horizontal Root Fractures in Three Maxillary Incisors: A Thirteen-Year Evaluation.

This case report documents the clinical approach adopted for three upper incisors with horizontal root fracture in the middle or cervical third. The proposed procedures involved maintaining pulp vitality and periodontal stability of the fractured teeth with 13 years of follow-up.

Types of External Root Resorption of Replanted Teeth: Analysis of the Clinical Aspects and of Interleukin-4 Gene Polymorphisms Involvement.

INTRODUCTION: The absence or presence of root resorption on the surface of a replanted tooth indicates an immune-inflammatory reaction. Recent research even suggests the participation of host predominant immunologic profile on types of resorptions detected on the root surface. Because interleukin 4 (IL-4) is an important anti-inflammatory cytokine, this study aimed to investigate the association of clinical variables and polymorphisms in IL4 with types of resorption of replanted teeth after 1 year of follow-up. METHODS: One hundred twenty-seven avulsed teeth that were replanted were selected. Periapical radiographs were taken after replantation and for 1 year to detect the types of root resorption. Real-time polymerase chain reaction was used to genotype IL4 polymorphisms. The χ2 and Z tests were performed to verify the association of clinical and genetic variables with the outcomes of replanted teeth (P < .05). RESULTS: An association was observed of extra-alveolar time, storage medium, and development of the root (P < .05), but not of IL4 polymorphisms, with the outcomes of replanted teeth (P > .05). CONCLUSIONS: Extraoral time, storage medium, and development of the root, but not IL4 polymorphisms, may influence the types of resorption of avulsed and replanted teeth in the first year after trauma.

Efficacy of protaper instruments during endodontic retreatment.

INTRODUCTION: The effectiveness of ProTaper Universal and ProTaper Retreatment rotary instruments was compared to the Hedström files in the removal of filling material from root canals. MATERIALS AND METHODS: Thirty-six extracted human mandibular premolars with a single straight root canal were shaped and filled with gutta-percha and AH Plus. The specimens were stored for 6 months at 37°C and at 100% relative humidity, and then randomly divided into three groups: PTU - removal of filling material performed with ProTaper Universal instruments; PTR - removal of filling material performed with ProTaper Retreatment instruments; HF - removal of filling material performed with Gates-Glidden burs, Hedström files and solvent. After the filling material removal and diaphanization, the specimens were longitudinally sectioned and images of the canal surfaces were scanned. The remaining areas of filling material were measured (Image Tool 3.0), and data was analyzed statistically (Kruskal-Wallis and Dunn tests). The time required for filling removal in each group was also recorded (one-way ANOVA and Tukey's HSD test). RESULTS: All groups presented remnants of filling material; PTU had the smallest amount and HF group presented the highest mean value (P< 0.05) in all the thirds. The cervical third had the smallest amount of material when compared with the other thirds (P< 0.05). HF group required a longer mean time, presenting significant difference (P< 0.05). CONCLUSION: Considering the time required and the amount of the filling removal, ProTaper Retreatment were not superior to ProTaper Universal, but both rotary instruments were more effective and less time-consuming than Hedström manual files.

Capacidade de selamento e penetração intratubular do MTA Fillapex e do AH Plus em dentes humanos / Sealing ability and penetration intratubular MTA Fillapex and AH Plus in human teeth

Introdução: O MTA é um importante material de uso na odontologia, com boas propriedades biológicas. As respostas experimentais aos cimentos endodônticos que utilizam este composto no selamento e preenchimento do sistema de canais radiculares, aliados a uma boa instrumentação e limpeza, podem ser importantes no processo de reparo periapical. Objetivo: Avaliar in vitro a profundidade de penetração de dois diferentes cimentos endodônticos nos túbulos dentinários e a infiltração bacteriana em obturações com os cimentos AH Plus e MTA Fillapex. Material e método: 34 pré-molares monorradiculados humanos foram selecionados, suas coroas removidas e suas raízes padronizadas em 16 mm, a seguir foram, então, divididos aleatoriamente em dois grupos de 15 espécimes e instrumentados com o sistema rotatório Pro Taper. Um grupo foi obturado com o cimento AH Plus (Grupo AH) e outro com MTA Fillapex (Grupo FI). Nestes grupos, avaliaram-se a infiltração coronária de bactérias para Enterococcus Faecalis e a profundidade de penetração nos túbulos dentinários. Para a aferição da infiltração bacteriana, usou-se o teste exato de Fisher; para a penetração intratubular, usou-se o teste-t. Resultado: Para a infiltração bacteriana, considerando o número de amostras infiltradas para AH e MTA Fillapex, houve diferença estatística significativa (p=0,0341). Na avaliação da penetração intratubular, a diferença entre os dois grupos de cimentos foi considerada estatisticamente significativa (p=0,0006). Conclusão: Ambos os cimentos apresentaram infiltração bacteriana, sendo que o MTA Fillapex teve pior desempenho. A capacidade de penetração nos túbulos dentinários do AH Plus foi significativamente maior que a do MTA Fillapex.

Introduction: The MTA is an important use in dentistry material with good biological properties. The experimental responses to sealers using this compound in the sealing and filling of the root canal system, combined with a good instrumentation and cleaning, may be important in the periapical healing process. Objective: To evaluate in vitro penetration depth of two different sealers in dentinal tubules and bacterial infiltration in fillings with AH Plus and MTA Fillapex cements. Material and method: 34 premolars human monorradiculados were selected, their removed and their standardized root crowns in 16mm, after then randomly divided into two groups of 15 specimens, and instrumented with rotary system Pro Taper. One group was obturated with cement AH Plus (group HA) and another MTA Fillapex (FI Group). These groups are evaluated for coronary infiltration of bacteria Enterococcus faecalis and the depth of penetration in the dentinal tubules. For the measurement of bacterial infiltration used Fisher's exact test for Intratubular penetration we used the t-test. Result: For bacterial infiltration, considering the number of infiltrated samples AH and MTA Fillapex, there was a statistically significant difference (p = 0.0341). In the evaluation of intratubular penetration, the difference between the two groups of cement was statistically significant (p = 0.0006). Conclusion: Both cements showed bacterial infiltration and the MTA Fillapex had worse performance, capabilities to enter the dentinal tubules AH Plus was significantly higher than the MTA Fillapex.

Influence of Atopy in the Outcome of Avulsed and Replanted Teeth during 5 Years of Follow-up.

INTRODUCTION: The goal of replantation after dental avulsion is to maintain the tooth in its socket. Presence of vital periodontal ligament cells on the root surface of the replanted tooth and the immunologic status of the patient are factors that protect against root resorption. It is known that dental constituents play an active role in root resorption by inducing specific and non-specific immune responses; however, little information exists regarding the influence of the acquired immune response on replantation. Therefore, the aim of this study was to evaluate the 5-year outcome of replantation in non-atopic and atopic patients. METHODS: Clinical and radiographic examinations were performed in 62 replanted teeth during a 5-year period. The evaluation of atopy was based on the patients' personal and family histories and skin prick test results. The χ2 and the Z tests were used to assess the association between atopy and the outcome of the replanted teeth (P < .05). RESULTS: There were significant differences between the 1-year and 5-year outcomes of the replanted teeth (P < .05) and atopic and non-atopic patients who had their teeth extracted because of inflammatory or replacement root resorption after 5 years (P < .05). CONCLUSIONS: Being atopic may offer the advantage of loss of fewer teeth because of replacement resorption, whereas being non-atopic may create an advantage of loss of fewer teeth because of inflammatory root resorption during the first 5 years after trauma.

Influence of the Calcium Hydroxide Intracanal Dressing on Dentinal Tubule Penetration of Two Root Canal Sealers.

OBJECTIVE: The aim of this study was to evaluate the effect of a calcium hydroxide (CH) dressing on the tubular penetration of two endodontic sealers, AH Plus (Dentsply Maillefer, Ballaigues, Switzerland) and MTA Fillapex (Angelus, Londrina, Brazil). METHODS: Seventy-two mandibular premolars with a single root canal were prepared with ProFile.04 rotary instruments (Dentsply Maillefer) and divided into four groups. In two groups, an intracanal CH dressing was placed for 15 days. The obturations were performed with lateral condensation of gutta-percha in combination with one of the tested sealers. The roots were transversely sectioned at the apical and middle levels. The percentage of sealer penetration in the root canal walls and the percentage of impregnated dentin area in the transverse sections were obtained using confocal laser scanning microscopy. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Games-Howell test. RESULTS: The CH dressing reduced the mean value of tubular penetration in the middle third of teeth obturated with AH Plus (P<0.01), whereas no difference was observed at the apical sections for both sealers. CONCLUSION: The CH dressing did not interfere with the apical penetration of both tested sealers, however, decreased the tubular penetration in the middle third of the AH Plus root canal fillings. Overall, MTA Fillapex presented higher tubular penetration than AH Plus obturations.

Apical extrusion of debris in flat-oval root canals after using different instrumentation systems.

INTRODUCTION: The purpose of this study was to evaluate the amount of apically extruded debris in flat-oval root canal systems during cleaning and shaping with different instrumentation systems. METHODS: Seventy-two mandibular incisors were randomly assigned to 4 groups (n = 18) according to the instrumentation system to be used: the ProTaper Next rotary system (PTN; Dentsply Tulsa Dental, Tulsa, OK), the WaveOne reciprocating system (WO, Dentsply Tulsa Dental), the Twisted File Adaptive (TFA; SybronEndo, Orange, CA) rotary/reciprocating system, and the Self-Adjusting File (SAF) system (ReDent-Nova, Ra'anana, Israel). Debris extruded during the instrumentation was collected and dried in preweighed Eppendorf tubes. Three consecutive weights were obtained for each tube, and the average was calculated. The data were analyzed using the t test and analysis of variance (Games-Howell test). RESULTS: The SAF produced significantly more debris compared with the other systems (P < .05). No significant difference was noted amongst the PTN, WO, and TFA (P > .05). CONCLUSIONS: Regardless of the instrumentation system used, apical extrusion of debris was exhibited at some level, regardless of the instrumentation system used. The SAF was associated with the highest amount of debris extrusion compared with PTN, WO, and TFA.

Lack of correlation between tubular dentine cement penetration, adhesiveness and leakage in roots filled with gutta percha and an endodontic cement based on epoxy amine resin.

OBJECTIVE: To analyze possible correlations among tubular dentine cement penetration, adhesiveness and apical leakage in fillings performed with gutta percha and an endodontic cement based on epoxy amine resin. MATERIAL AND METHODS: Sixty similar, extracted human mandibular central incisors were irrigated, instrumented and filled following the same protocol. First, apical leakage was quantified by fluid filtration tests. Then, these same specimens were sectioned for analysis of tubular dentine cement penetration and the middle thirds were submitted to push-out tests to analyze the adhesiveness of the fillings. RESULTS: In brief, the means and standard deviations with a confidence interval of 95% were as follows: tubular dentine cement penetration (8.875±4.540), adhesiveness (4.441±2.683) and apical leakage (0.318±0.215). The data were confronted using the Pearson's test (P>0.05), and it was possible to prove that there was no correlation between (1) tubular dentine cement penetration and apical leakage (r2: 0.08276), (2) tubular dentine cement penetration and adhesiveness (r2: -0.2412) and (3) adhesiveness and apical leakage (r2: 0.1340). CONCLUSION: After analysis of these data, it could be observed that there exists no correlation among the variables analyzed in this study.

Lack of correlation between tubular dentine cement penetration, adhesiveness and leakage in roots filled with gutta percha and an endodontic cement based on epoxy amine resin

Objective: To analyze possible correlations among tubular dentine cement penetration, adhesiveness and apical leakage in fillings performed with gutta percha and an endodontic cement based on epoxy amine resin. Material and Methods: Sixty similar, extracted human mandibular central incisors were irrigated, instrumented and filled following the same protocol. First, apical leakage was quantified by fluid filtration tests. Then, these same specimens were sectioned for analysis of tubular dentine cement penetration and the middle thirds were submitted to push-out tests to analyze the adhesiveness of the fillings. Results: In brief, the means and standard deviations with a confidence interval of 95% were as follows: tubular dentine cement penetration (8.875±4.540), adhesiveness (4.441±2.683) and apical leakage (0.318±0.215). The data were confronted using the Pearson's test (P>0.05), and it was possible to prove that there was no correlation between (1) tubular dentine cement penetration and apical leakage (r2: 0.08276), (2) tubular dentine cement penetration and adhesiveness (r2: -0.2412) and (3) adhesiveness and apical leakage (r2: 0.1340). Conclusion: After analysis of these data, it could be observed that there exists no correlation among the variables analyzed in this study. .

Enxerto autógeno e alterações pulpares / Autogenous graft and pulp alterations

Introdução: as cirurgias orais com remoções ósseas e secções profundas nos tecidos moles, evidentemente, causam alterações significantes em tais estruturas, destacando-se as vasculares, inclusive dos vasos que irrigam diretamente a polpa dental. Dependendo da extensão do leito cirúrgico, pode-se cessar a irrigação do tecido pulpar. Tais alterações estão confirmadas na literatura, principalmente em cirurgias Le Fort I, suturas intermaxilares e osteotomias. Relato de caso: foi descrito e discutido um caso proveniente do ambulatório do curso de residência em cirurgia bucomaxilofacial no qual após a retirada de tecido ósseo do mento para enxerto na maxila dois elementos dentários apresentaram alteração de cor. Posteriormente, foi evidenciada a necrose asséptica dos referidos dentes, os quais receberam tratamento endodôntico e clareamento interno. Considerações finais: nos procedimentos cirúrgicos onde ocorre uma profunda intervenção em vasos sanguíneos da face são necessários rigorosos planejamentos aliados a acompanhamento pós-cirúrgico em razão das, entre outras possibilidades, alterações pulpares.

Efficacy of five rotary systems versus manual instrumentation during endodontic retreatment.

The purpose of this study was to evaluate the efficiency of ProFile, GT, ProTaper, Race and K3 rotary instruments compared with hand K-files for removal of gutta-percha during retreatment. Sixty mandibular premolars were instrumented with GT rotary files and filled by thermomechanical compaction of gutta-percha and AH Plus sealer. The teeth are randomly divided into 6 groups of 10 specimens each. The roots were split longitudinally, digital images were created using a flatbed scanner, and the areas with remaining filling material were demarcated using Image Tool 1.21 software. The results indicate that GT left significantly less (p<0.05) remaining filling material (1.18 ± 1.47) than hand (3.70 ± 3.16) and Hero instruments (2.99 ± 2.58). There was no statistically significant difference (p<0.05) among the others techniques: ProFile (1.99 ± 2.66), ProTaper (2.00 ± 1.99) and K3 (2.71 ± 2.87) when compared with GT. In conclusion, GT, ProFile, ProTaper and K3 were more effective in removing gutta-percha than manual and Hero instruments.

Accuracy of Root ZX II in locating foramen in teeth with apical periodontitis: an in vivo study.

INTRODUCTION: This study was conducted in vivo to investigate the accuracy of Root ZX II in locating the apical foramen in teeth with apical periodontitis (AP). METHODS: Twenty-seven single-root teeth scheduled for extractions were selected; in AP group, there were 12 teeth with pulp necrosis and radiographic evidence of apical lesions, and VT group consisted of 15 vital teeth. After endodontic access, the coronal portion of the canal was flared, and electronic measurement was performed by using a 15 K-file until the device level reading "APEX" was reached. The file was fixed in place, and the tooth was extracted. The apical third of the root was shaved until exposure of the file. The distance from the file tip to the most coronal border of the apical foramen was obtained. RESULTS: The mean distance in AP group was +0.117 (standard deviation, 0.373) and in VT group was -0.105 (standard deviation, 0.218). The unpaired t test showed no difference between the groups when comparing the mean distances (P > .05). The apical foramen was accurately located within ±0.5 mm in 83% of the teeth in AP group and in 100% of VT group. Statistical analysis showed no difference between the groups (P = .1092). CONCLUSIONS: The Root ZX II device was accurate in locating the apical foramen regardless of the presence of AP.

Prospecção de atividade inibitória da pasta de hidróxido de cálcio e acetazolamida sobre Enterococcus faecalis e Candida albicans / Antimicrobial effect of calcium hydroxide paste and acetazolamide against the Enterococcus faecalis and Candida albicans

Introdução: A medicação intracanal é fundamental para o tratamento de um dente avulsionado, sendo a pasta de hidróxido de cálcio comumente indicada. A acetazolamida é uma substância inibidora da anidrase carbônica e da reabsorção óssea, podendo ser sugerida como medicação intracanal em dentes avulsionados. Contudo, para que uma substância seja sugerida, estudos devem comprovar sua eficácia tanto in vitro como in vivo. Objetivo: Avaliar in vitro a ação antimicrobiana da pasta de hidróxido de cálcio e da acetazolamida, associadas a diferentes veículos, contra os micro-organismos Enterococcus faecalis e Candida albicans. Materiais e métodos: As formulações selecionadas foram: acetazolamida (pó) com soro fisiológico; acetazolamida (pó) com glicerina; acetazolamida e hidróxido de cálcio (pó) em porções iguais com soro fisiológico; acetazolamida e hidróxido de cálcio (pó) em porções iguais adicionando-se glicerina; acetazolamida (líquido) e hidróxido de cálcio (pó) com soro fisiológico. Como controle positivo foram utilizadas concentrações de clorexidina de 20%, 10%, 5%, 2,5%, 1,25% e 0,65% e como controle negativo a glicerina. O experimento foi realizado por teste de difusão em ágar. Resultados: Não houve inibição do crescimento das bactérias com os medicamentos utilizados, apenas com o controle positivo.Conclusão: As formulações de hidróxido de cálcio e acetazolamida não apresentaram atividade inibitóriacontra o E. faecalis e C. albicans.

Introduction: The intracanal medication is essential for the treatment of avulsed tooth, being the calcium hydroxide paste usually indicated. The acetazolamide is an inhibiting substance of carbonic anhydrase and the bone resorption, being suggested as intracanal medication in avulsed teeth. However, for this substance became an alternative as intracanal therapeutic agent, it must be tested in vitro and in vivo. Objective: To evaluate, in vitro, the antimicrobial action of calcium hydroxide paste and acetazolamide associated with different vehicles, against the Enterococcus faecalis and Candida albicans. Materials and methods: The experimental groups were: acetazolamide (powder) with physiological serum; acetazolamide (powder) with glycerin; acetazolamide and calcium hydroxide (powder) in equal portions with physiological serum; acetazolamide and calcium hydroxide (powder) in equal portions added with glycerin; acetazolamide (liquid) and calcium hydroxide (powder) with physiological serum. Clorexidine was used for positive control in concentrations of 20%, 10%, 5%, 2.5%, 1.25% and 0.65% and glycerin was used as negative control. The study was carried through by test of diffusion in agar. Results: No experimental groups showed inhibition of the bacterial growth, only inhibited by the positive control. Conclusion: The groups with calcium hydroxide and acetazolamide did not show antimicrobial activity against the E. faecalis and C. albicans.

Efficacy of five rotary systems versus manual instrumentation during endodontic retreatment

The purpose of this study was to evaluate the efficiency of ProFile, GT, ProTaper, Race and K3 rotary instruments compared with hand K-files for removal of gutta-percha during retreatment. Sixty mandibular premolars were instrumented with GT rotary files and filled by thermomechanical compaction of gutta-percha and AH Plus sealer. The teeth are randomly divided into 6 groups of 10 specimens each. The roots were split longitudinally, digital images were created using a flatbed scanner, and the areas with remaining filling material were demarcated using Image Tool 1.21 software. The results indicate that GT left significantly less (p<0.05) remaining filling material (1.18 ± 1.47) than hand (3.70 ± 3.16) and Hero instruments (2.99 ± 2.58). There was no statistically significant difference (p<0.05) among the others techniques: ProFile (1.99 ± 2.66), ProTaper (2.00 ± 1.99) and K3 (2.71 ± 2.87) when compared with GT. In conclusion, GT, ProFile, ProTaper and K3 were more effective in removing gutta-percha than manual and Hero instruments.

O propósito deste estudo foi avaliar a eficiência dos instrumentos rotatórios ProFile, GT, ProTaper, Race e K3 comparados com limas K para a remoção do material obturador durante o retratamento. Sessenta pré-molares inferiores foram instrumentados com o sistema rotatório GT e obturados usando a técnica de compactação termomecânica de guta-percha com cimento AH Plus. Os dentes foram divididos aleatoriamente em seis grupos de dez espécimes cada. As raízes foram seccionadas longitudinalmente, imagens digitais foram criadas através de um scanner, e as áreas de remanescentes de material foram medidas usando o programa Image Tool 1.21. Os resultados indicaram que o GT deixou significantemente menos material remanescente (1,18 ± 1,47) do que os instrumentos manuais (3,70 ± 3,16) e os instrumentos Hero (2,99 ± 2,58) (p<0,05). Não houve diferença estatisticamente significante entre as outras técnicas ProFile (1,99 ± 2,66), ProTaper (2,00 ± 1,99) e K3 (2,71 ± 2,87) quando comparadas com o GT. Como conclusão, GT, ProFile, ProTaper e K3 foram revelados como mais efetivos em remover a guta-percha do que os instrumentos manuais e os instrumentos Hero.