Influence of concentration, irrigation method, and root canal third on intratubular penetration of sodium hypochlorite - a broad statistical analysis.

Background: The permanence of microorganisms in the root canal system represents the main cause of endodontic failure. Considering the impossibility of effective action of the endodontic files in ramifications of the main canal and mainly inside the dentinal tubules, a better understanding of the irrigation dynamics to enhance endodontic prognosis is essential. Objective: To evaluate the depth of intratubular penetration values of sodium hypochlorite (NaOCl) (dependent variable) by comparing different concentrations, methods of irrigation, and root canal thirds (independent variables) and to investigate the existence of interactions among them, capable of influencing the dependent variable. Material and Methods: 40 roots from extracted human maxillary central incisors were stained and instrumented according to four irrigation protocols (n. 10): conventional irrigation (CI) at each use or change of instrument, and final irrigation with 5ml of 2.5% or 5.25% NaOCl, with or without passive ultrasonic irrigation (PUI), respectivelly. Measurements based on stereomicroscopic images were obtained, and the data were subjected to statistical analysis (p< 0.05). Results: The highest depth values of intratubular penetration of NaOCl were observed in the cervical third, at 5.25%, and by PUI. When only two independent variables were analyzed in association, the highest penetration depth values of NaOCl were obtained at 5.25%, regardless of irrigation method, at 5,25%, in the cervical third, and; in the cervical third, despite of irrigation method. Considering the three independent variables simultaneously, the highest depth values of intratubular penetration of NaOCl were observed in the cervical third, at 5.25%, no matter the irrigation method. The interaction between the independent variables on the penetration depth values of NaOCl was only confirmed considering the irrigation method and root canal third. Conclusions: Intratubular penetration of NaOCl was influenced by the three independent variables individually and when the irrigation method and root canal third were considered simultaneously. Key words:Dentinal tubules, Depth, Disinfection, Irrigation, Root canal system, Sodium hypochlorite.

Effects of using different root canal sealers and protocols for cleaning intraradicular dentin on the bond strength of a composite resin used to reinforce weakened roots / Efectos del uso de diferentes selladores de conductos radiculares y protocolos para limpiar la dentina intrarradicular sobre la fuerza de unión de una resina compuesta utilizada para reforzar raíces debilitadas

Background: This study evaluated the effects of using different root canal sealers and protocols for cleaning intraradicular dentin on the bond strength of a composite resin used to reinforce weakened roots. Material and Methods: Sixty-four roots of extracted human maxillary canines were weakened, prepared and filled with two different endodontic sealers (Endofill and AH Plus). In half of the sample, set aside for each respective sealer, excess filling material was cleaned. In the other half, the weakened areas were not cleaned, and the excess of sealer was spread on the intraradicular dentin. Intentionally worn areas inside each root were restored with a microhybrid light-cure composite resin (Z100) to reinforce them, with and without acid etching. Prefabricated metal posts were fixed with a dual resin cement (RelyX ARC), and the specimens were submitted to a pull-out test. Statistical analysis was performed by means of Shapiro-Wilk, analysis of variance (one-way ANOVA) and Tukey-Kramer tests (p<0.05). Results: The groups filled with Endofill (GI, GII, GIII, GIV) had the lowest bond strength values, which were similar among each other (p>0.05).The greatest bond strength values were observed in roots filled with AH Plus (GV, GVI, GVII, GVIII), mainly without cleaning of the weakened areas, and followed by acid etching (GVII), and also with cleaning of the weakened areas, however, with no acid etching (GVI) (p<0.05). Conclusion: The greatest bond strength values were observed in roots filled with AH Plus; (1) without cleaning of the weakened areas and with acid etching, and; (2) with cleaning of the weakened areas, but without acid etching.

Antecedentes: este estudio evaluó los efectos del uso de diferentes selladores de conductos radiculares y protocolos para limpiar la dentina intrarradicular sobre la fuerza de unión de una resina compuesta utilizada para reforzar las raíces debilitadas. Material y Métodos: Sesenta y cuatro raíces de caninos maxilares humanos extraídos fueron debilitadas, preparadas y rellenadas con dos selladores endodónticos diferentes (Endofill y AH Plus). En la mitad de la muestra, reservada para cada sellador respectivo, se limpió el exceso de material de relleno. En la otra mitad, las áreas debilitadas no se limpiaron y el exceso de sellador se esparció sobre la dentina intrarradicular. Las áreas desgastadas intencionalmente dentro de cada raíz se restauraron con una resina compuesta fotopolimerizable microhíbrida (Z100) para reforzarlas, con y sin grabado ácido. Los postes metálicos prefabricados se fijaron con un cemento de resina dual (RelyX ARC) y los especímenes se sometieron a una prueba de extracción. El análisis estadístico se realizó mediante Shapiro-Wilk, análisis de varianza (ANOVA de una vía) y pruebas de Tukey-Kramer (p<0,05). Resultados: Los grupos rellenos con Endofill (GI, GII, GIII, GIV) presentaron los valores más bajos de fuerza de unión, los cuales fueron similares entre sí (p>0,05). Los mayores valores de fuerza de unión se observaron en raíces rellenas con AH Plus (GV, GVI, GVII, GVIII), principalmente sin limpieza de las áreas debilitadas, seguido de grabado ácido (GVII), y también con limpieza de las áreas debilitadas aunque sin grabado ácido (GVI) (p<0.05). Conclusión: Los mayores valores de fuerza de unión se observaron en las raíces rellenas con AH Plus; (1) sin limpieza de las áreas debilitadas y con grabado ácido, y; (2) con limpieza de las áreas debilitadas, pero sin grabado ácido.

Evaluation of 17% EDTA and 10% citric acid in smear layer removal and tubular dentin sealer penetration.

The purpose of this study was to compare the efficacy of different chelating solutions (17% EDTA and 10% citric acid) on the smear layer removal, and their effect on tubular dentin sealer penetration. Sixty root canals were prepared and distributed into four groups (n = 15) according to the final irrigation protocol: G1, final irrigation with 2.5 mL of distilled water; G2, final irrigation with 2.5 mL of 2.5% sodium hypochlorite solution; G3, final irrigation with 2.5 mL of 17% EDTA; and G4, final irrigation with 2.5 mL of 10% citric acid. Five specimens from each group were not filled to assess smear layer removal by scanning electron microscopy. Ten specimens from each group were filled for analysis of sealer penetration into dentinal tubules by confocal laser scanning microscopy. Smear layer removal (Kruskal-Wallis and Dunn's tests) and sealer penetration (F and Tukey's tests) were statistically analyzed with 95% of significance level. G3 and G4 had greater smear layer removal rates in the cervical and middle thirds, in comparison with G1 and G2 (p < .05). G3 and G4 had the highest percentages of sealer penetration in all thirds, in comparison with G1 and G2 (p < .05). Smear layer removal was effective only at the cervical and middle thirds when the chelating solutions were used. Sealer penetration into the dentinal tubules significantly increased in all root thirds when the specimens were treated with both chelating solutions.

Surgical resolution of an aggressive iatrogenic root perforation in a maxillary central incisor: a case report with a 4-year follow-up.

The prognosis of teeth with root perforations depends on several factors, including size, location, and time since occurrence. Root perforations are clinical situations that can be solved by either nonsurgical or surgical approaches. The purpose of this article is to present a case of an aggressive iatrogenic root perforation in a maxillary right central incisor solved surgically using mineral trioxide aggregate (MTA). Even in an unfavorable situation, MTA was able to induce new bone formation and reestablish gingival and periodontal health, as confirmed in follow-up examinations at 2 and 4 years.

Management of progressive apical root resorption 13 years after dental trauma and primary endodontic treatment.

Many studies have focused on the search for a restorative material with good sealing properties and biocompatibility for treatment of teeth with open apices and necrotic pulps, which can result from periradicular disease and root resorption. Mineral trioxide aggregate (MTA) has exhibited promising clinical results in retrograde fillings and pulpotomies as well as for treatment of root perforations, root resorptions, incomplete root formations, and pulpal necrosis. This case report describes the management of a progressive apical root resorption in a previously traumatized tooth that had been endodontically treated. Five years of clinical and radiographic follow-up demonstrated the clinical efficacy of MTA in limiting the inflammatory resorptive process and promoting apexification and regeneration of periradicular tissue.

The Impact of Apical Patency in the Success of Endodontic Treatment of Necrotic Teeth with Apical Periodontitis: A Brief Review.

Accumulation of soft tissue or dentinal remnants in the apical region is a common event that can cause blockage of root canals. This event can be avoided if apical patency is performed during the root canal shaping procedures. However, there is no consensus on the role of apical patency in relation to the success of endodontic treatment of necrotic teeth with apical periodontitis. Therefore, the purpose of this paper was to conduct a brief review on the role of apical patency in guaranteeing the success of endodontic treatments of necrotic teeth with apical periodontitis considering two other key points; the root canal anatomy and microbiology.

Antimicrobial activity of calcium hydroxide associated with anew vehicle (Triethanolamine) / Atividade antimicrobiana do hidróxido de cálcio associado à um novo veículo (Trietanolamina)

Objetivo: O objetivo deste estudo foi avaliar a capacidade antimicrobiana do hidróxido de cálcio associado à dois veículos convencionais (anestésico líquido e azeite de oliva) e um novo veículo (Trietanolamina). Material e Métodos: Inicialmente, os micro-organismos foram coletados de quatro incisivos superiores de um mesmo paciente que apresentavam tratamentos endodônticos insatisfatórios e periodontites apicais persistentes utilizando cones de papel absorvente esterilizados inseridos nos canais radiculares após a remoção do material obturador. Em seguida, estes foram cultivados em BHI durante 24 h e colocados em 10 placas de Petri com três orifícios preenchidos com as medicações avaliadas. Após 48 e 72 h, os halos de inibição foram aferidos. Resultados: Após aplicação do teste de Kruskal-Wallis com nível de significância de 1% (α = 0,01) foi observado que, hidróxido de cálcio associado à Trietanolamina, apresentou resultados semelhantes àqueles produzidos pelo líquido anestésico. Ambas as combinações foram superiores ao hidróxido de cálcio veiculado ao azeite de oliva. Conclusão: Considerando os resultados deste estudo in vitro, é possível concluir que Trietanolamina pode ser uma alternativa viável para ser utilizada como veículo associado ao hidróxido de cálcio.

Objective: The aim of this study was to evaluate the antimicrobial effectiveness of calcium hydroxide associated with a two conventional (anesthetic liquidand olive oil) and a new vehicle (Triethanolamine). Material and methods: Initially, microorganisms were collected from four upper incisors presenting unsatisfactory root canal treatments and persistent apical periodontitis from the same patient using sterile absorbent paper cones placed inside the root canal following initial access and root filling removal. Next, they were grown in a BHI culturemedium for 24 h. Afterwards, they were placed in 10 Petri dishes with 3 holes, where different formulations of the medications studied were placed. After 48 and 72 h, readings were taken of the growth inhibition halos. Results: After using Kruskal-Wallis test with significance level of 1% (α = 0.01) it was observed that, calcium hydroxide associated with Triethanolamine, produced results similar to those produced by the anesthetic liquid. Both combinations were superior to the association with olive oil. Conclusion: Considering the results of this in vitrostudy, it is possible to consider that Triethanolamine can be a viable alternative to be used as a vehicleassociated with the calcium hydroxide.

Maxillary first molar with 8 root canals detected by CBCT scanning: a case report.

Maxillary molars are prone to exhibit some of the most complex root canal configurations in endodontics. These complexities can result in diagnostic dilemmas, as well as management challenges. This case report illustrates how a cone beam computed tomography (CBCT) scan confirmed an unusual maxillary first molar with 3 root canals each in the mesiobuccal and distobuccal roots and 2 canals in the palatal root. This article illustrates how CBCT scanning and a dental operating microscope can facilitate a better understanding of complex root canal anatomies, ultimately allowing the dentist to clean, shape, and obturate root canal systems more efficiently.

Histological analysis of the biocompatibility of calcium hydroxide associated with a new vehicle.

BACKGROUND: Several substances have been researched to act as vehicles associated with calcium hydroxide. The specific type of vehicle is directly related to the effectiveness of the ionic dissociation, antimicrobial action, and biocompatibility of this medication. AIM: To make a histological evaluation of the biocompatibility of calcium hydroxide associated with a new vehicle (triethanolamine), compared with polyethylene glycol, saline solution, and olive oil. MATERIALS AND METHODS: Fifty mice of guinea pig species were randomly divided into five groups (n = 10) according to each vehicle used--Group 1: calcium hydroxide, Group 2: triethanolamine, Group 3: polyethylene glycol, Group 4: saline solution, and Group 5: olive oil--and further divided into subgroups according to the two analysis periods--(a) 30 and (b) 90 days. Teflon carriers filled with the evaluated substances were placed in standardized bone cavities in the anterior mandible region. The animals were euthanized to perform a histological analysis after the time periods analyzed. RESULTS: In 30 days, specimens from Groups 1, 3, and 5 showed a very pronounced inflammatory response. Specimens from Group 2 showed an inflammatory reaction ranging from mild to severe, with rapid resorption of the material and progressive advancement of osteoid tissue into the teflon carriers. Specimens from Group 4 showed a moderate inflammatory reaction. In 90 days, specimens from Group 1 showed a very pronounced fibrous replacement. In regard to Group 2 specimens, the tested material was solubilized and replaced by newly formed bone tissue. For Groups 3 and 5 specimens, the inflammatory reaction went from acute to moderate. In relation to Group 4 specimens, an organized bone formation process was observed. CONCLUSIONS: Specimens from Group 2 showed higher biocompatibility, especially as compared with the specimens from Groups 3 and 5.

Ausência de correlação entre a densidade radiográfica da obturação e sua capacidade seladora / Lack of correlation between radiographic density of filling and fluid infiltration

Objetivo: o objetivo deste estudo foi avaliar a existênciade correlação entre a densidade radiográfica das obturaçõese sua capacidade de selamento. Material: foramselecionados para esta pesquisa 56 incisivos inferiorescom canais únicos e retos, completa formação radiculare sem complexidades anatômicas. Essas característicasforam observadas visualmente e radiograficamente.Todos os espécimes foram instrumentados utilizandoo sistema Profile 04 até o instrumento 35 seguindo omesmo protocolo de irrigação. As obturações foramexecutadas pela técnica de condensação lateral e cimentoAH Plus. Em seguida, foram feitas radiografias nosentido mesiodistal para análise da densidade radiográ-fica das obturações pela mensuração de espaços vaziosutilizando o software Axiovision. Resultados: As médiase os desvios-padrão foram de 0,311 ± 0,215μL/min e7,97 ± 3,93% para a infiltração e a porcentagem de espaçosvazios nas obturações, respectivamente. Conclusões:de acordo com os resultados deste estudo, nenhumacorrelação foi encontrada entre e porcentagemde espaços visíveis radiograficamente e a capacidade deselamento das obturações (p = 0,587).

Perfuração radicular apical iatrogênicarealizada durante o retratamento de umincisivo central inferior: relato de um caso clínico com cinco anos de acompanhamento / Iatrogenic apical root perforation performed during retreatment of a mandibular central incisor: a five-year follow-up case study

Introdução: as perfurações radiculares iatrogênicas ocorremem cerca de 2 a 12% dos casos. Estas estão associadas,principalmente, à realização de acessos incorretos, tentativade localização de canais, instrumentações, reinstrumentaçõese remoção de instrumentos fraturados. Quando ocorrem nosterços apicais, podem levar, inclusive, à perda do elementodentário devido à maior complexidade do tratamento. Objetivo:o objetivo deste trabalho foi relatar a ocorrência de umaperfuração radicular apical iatrogênica realizada durante o retratamentode um incisivo central inferior. Métodos: após arealização dos exames clínicos e radiográficos, chegou-se a umdiagnóstico de necrose pulpar e lesão periapical assintomáticano incisivo central inferior direito. Consequentemente, o tratamentoendodôntico não cirúrgico foi recomendado. Após arealização da primeira intervenção, foi possível observar umresultado radiográfico insatisfatório. Por este motivo, decidiu--se pelo retratamento. Após a realização deste procedimento,a radiografia final evidenciou uma ampla perfuração apicaldecorrente de um desvio durante a fase de instrumentação.Em virtude da ausência total de sintomatologia e pela complexidadedo caso, optou-se somente pelo acompanhamento.Resultados: o monitoramento clínico e radiográfico apóscinco anos mostraram o êxito do tratamento. Conclusão:Em situações com características semelhantes, tão importantequanto as ações clínicas propriamente ditas, é estabelecer umacorreta decisão visando tanto o conforto do paciente quanto alongevidade do elemento dentário na cavidade bucal.

Cirurgia paraendodôntica utilizando o cimento de Portland como material retrobturador: relato de um caso clínico com cinco anos de acompanhamento / Paraendodontic surgery using Portland cement as retrofilling material: A 5-year follow-up case report

Cirurgia paraendodôntica utilizando o cimento de Portland como material retrobturador: relato de um caso clínico com cinco anos de acompanhamento

S-Shaped Canals: A Series of Cases Performed by Four Specialists around the World.

Recognition of anatomical variations is a real challenge for clinicians undertaking therapy regardless of the teeth that are to be treated. The extent of the curvature is one of the most important variables that could lead to instrument fracture. In clinical conditions, two curves can be present in the same root canal trajectory. This type of geometry is denoted as the "S" shape, and it is a challenging condition. This report describes a different clinical and educational scenario where four specialists around the world present different approaches for the treatment of root canals with double curvatures or S-shaped canals. Endodontic therapy is a very nuanced and challenging science and art. The clinical and teaching experience of the authors show different approaches that can be successfully employed to treat challenging teeth having roots with multiple curves. The necessity of precise knowledge of the root canal morphology and its variation is also underlined.

Constricted canals: a new strategy to overcome this challenge.

Negotiation of constricted canals can be a challenge during endodontic treatment. Over the years, several strategies have been presented in order to overcome the difficulties imposed by this anatomical feature. This paper presents three cases using a different protocol from that recommended by the manufacturer of the Protaper System in order to facilitate the negotiation of constricted canals. These cases suggest that the modified protocol shown is able to perform the shaping process with less resistance, reducing the risk of instrument separation and performing an effective process to reach the apical thirds in constricted canals.

Maxillary premolar with 4 separate canals.

INTRODUCTION: Recognition of anatomic variations is a challenge for clinicians regardless of which tooth is treated. Maxillary premolars usually have 2 root canals, but the presence of 3 distinct root canals has been reported in 1%-6% of cases. METHODS AND RESULTS: This report describes the case of a maxillary right second premolar with 4 separate canals: 1 mesial, 1 palatal, and 2 distal canals. This was confirmed by using cone-beam computed tomography and was successfully treated with rotary files and obturated by using a warm vertical compaction technique. CONCLUSIONS: The clinical significance of the present case is that this is the first report of 3 roots and 4 separate canals in a maxillary premolar. Precise knowledge of root canal morphology and its variation is also underlined. Cone-beam computed tomography examination and the operating microscope are excellent tools for identifying and managing these complex root canal systems.

Endodontists perceptions of single and multiple visit root canal treatment: a survey in Florianópolis - Brazil

Introduction: One of the main debates that have occurred in Endodontics is about the amount of sessions required to complete an appropriate treatment. There are very different philosophies regarding this matter. Objective: to the aim of this study was to investigate the Endodontists' point of view regarding single and multiple visit root canal treatment, identifying the basis on which the choice is made and how the information necessary for the choice is acquired. Material and methods: Endodontists registered in the dental practice board of Florianópolis/SC were contacted, and if they agreed to participate, they were interviewed using a questionnaire. The following topics were addressed: demographics, current clinical procedures, treatment rationales and preferences. Forty-three endodontists agreed to participate in the study. Results: Single visit endodontic treatment is carried out in 59.5% of biopulpectomy cases, 31.0% of necropulpectomy cases without lesion and only 11.9% in necropulpectomy cases with periapical lesion. The presence of vital pulp (81.4%) and a canal without exudate (93.0%) are the most important criteria for carrying out single visit endodontic treatment. The most used intracanal medication was calcium hydroxide. The lack of studies comparing long-term success on single visit endodontic treatment is considered an important issue to determine this therapy. Conclusion: It can be concluded that Florianopolis-Brazil endodontists prefer multiple visit over single visit root canal treatment in pulp necrosis cases. When pulp vitality is not compromised there is an increase in the number of endodontists who choose single visit root canal treatment.

Morphological changes related to age in mesial root canals of permanent mandibular first molars.

The aim of this study was to evaluate age-related morphological canal changes in mesial root canals of mandibular first molars of known ages. Fifty-six specimens were selected for this study and distributed into the following four age groups (n. 14): a) Group of children under 13 years, b) Group of adolescents (from 14 to 19 years), c) Group of young adults (from 20 to 39 years) and d) Group of older adults (over 40 years). The specimens were in perfect condition because after extraction they were carefully cleaned, sterilized, identified and stored in water. In order to improve the cleaning, they were placed in 1% sodium hypochlorite solution for four hours and rinsed in 10 vol. hydrogen peroxide for 8 hours. After that, a clearing technique was performed to illustrate root canal anatomy. Digitalized images of all samples were obtained by use of a stereomicroscope. Canals were noticeably simpler in older adults: they were sharply defined and narrow, sometimes too narrow. Calcification nuclei were not found and there were only a few remains of internuclear spaces. The canal system appeared cleaner, clearer and more sharply defined than in the other age groups. It may be concluded that there is a correlation between aging and morphological changes in the mesial root canals of mandibular first molars.

Micro-computed tomography and bond strength analysis of different root canal filling techniques.

INTRODUCTION: The aim of this study was to evaluate the quality and bond strength of three root filling techniques (lateral compaction, continuous wave of condensation and Tagger's Hybrid technique [THT]) using micro-computed tomography (CT) images and push-out tests, respectively. MATERIALS AND METHODS: Thirty mandibular incisors were prepared using the same protocol and randomly divided into three groups (n=10): Lateral condensation technique (LCT), continuous wave of condensation technique (CWCT), and THT. All specimens were filled with Gutta-percha (GP) cones and AH Plus sealer. Five specimens of each group were randomly chosen for micro-CT analysis and all of them were sectioned into 1 mm slices and subjected to push-out tests. RESULTS: Micro-CT analysis revealed less empty spaces when GP was heated within the root canals in CWCT and THT when compared to LCT. Push-out tests showed that LCT and THT had a significantly higher displacement resistance (P<0.05) when compared to the CWCT. Bond strength was lower in apical and middle thirds than in the coronal thirds. CONCLUSIONS: It can be concluded that LCT and THT were associated with higher bond strengths to intraradicular dentine than CWCT. However, LCT was associated with more empty voids than the other techniques.

Morphological changes related to age in mesial root canals of permanent mandibular first molars

The aim of this study was to evaluate age-related morphologicalcanal changes in mesial root canals of mandibular first molars ofknown ages. Fifty-six specimens were selected for this study anddistributed into the following four age groups (n. 14): a) Groupof children under 13 years, b) Group of adolescents (from 14 to19 years), c) Group of young adults (from 20 to 39 years) and d)Group of older adults (over 40 years). The specimens were in perfectcondition because after extraction they were carefullycleaned, sterilized, identified and stored in water. In order toimprove the cleaning, they were placed in 1% sodium hypochloritesolution for four hours and rinsed in 10 vol. hydrogenperoxide for 8 hours. After that, a clearing technique was performedto illustrate root canal anatomy. Digitalized images of allsamples were obtained by use of a stereomicroscope. Canals werenoticeably simpler in older adults: they were sharply defined andnarrow, sometimes too narrow. Calcification nuclei were notfound and there were only a few remains of internuclear spaces.The canal system appeared cleaner, clearer and more sharplydefined than in the other age groups. It may be concluded thatthere is a correlation between aging and morphological changesin the mesial root canals of mandibular first molars...

O objetivo do presente estudo foi avaliar as alterações morfológicasrelacionadas com a idade em canais radiculares mesial deprimeiros molares inferiores. Cinqüenta e seis espécimes foramselecionados para este estudo. Os espécimes foram distribuídosem quatro grupos etários (n. 14): a) Grupo de crianças menoresde 13 anos, b) grupo de adolescentes (de 14 a 19 anos), c) Grupode jovens adultos (de 20 a 39 anos ) e d) Grupo de adultos (acimade 40 anos). Após as extrações os elementos foram cuidadosamentelimpos, esterilizados, identificadas e armazenadas emágua. A fim de melhorar a limpeza, foram colocados numasolução de hipoclorito de sódio a 1%, durante quatro horas eenxaguados em 10 vol. peróxido de hidrogénio durante 8 horas.Depois, uma técnica de diafanização foi realizada para ilustrar aanatomia do canal radicular. As imagens digitalizadas de todasas amostras foram obtidas através da utilização de um estereoscópio.Os canais foram visivelmente mais simples em adultosmais velhos: eles foram bem definidas e estreito, por vezes,demasiado estreito. Núcleo de calcificação não foi encontrado ehavia apenas alguns restos de espaços internucleares. O sistemade canal apareceu mais limpa, mais clara e mais bem definidado que nas outras faixas etárias. Pode-se concluir que há umacorrelação entre as alterações do envelhecimento e morfológicasnos canais radiculares mesial de primeiros molares inferiores...

Morphological changes related to age in mesial root canals of permanent mandibular first molars. / Morphological changes related to age in mesial root canals of permanent mandibular first molars.

The aim of this study was to evaluate age-related morphological canal changes in mesial root canals of mandibular first molars of known ages. Fifty-six specimens were selected for this study and distributed into the following four age groups (n. 14): a) Group of children under 13 years, b) Group of adolescents (from 14 to 19 years), c) Group of young adults (from 20 to 39 years) and d) Group of older adults (over 40 years). The specimens were in perfect condition because after extraction they were carefully cleaned, sterilized, identified and stored in water. In order to improve the cleaning, they were placed in 1

sodium hypochlorite solution for four hours and rinsed in 10 vol. hydrogen peroxide for 8 hours. After that, a clearing technique was performed to illustrate root canal anatomy. Digitalized images of all samples were obtained by use of a stereomicroscope. Canals were noticeably simpler in older adults: they were sharply defined and narrow, sometimes too narrow. Calcification nuclei were not found and there were only a few remains of internuclear spaces. The canal system appeared cleaner, clearer and more sharply defined than in the other age groups. It may be concluded that there is a correlation between aging and morphological changes in the mesial root canals of mandibular first molars.