Physicochemical properties and penetration into dentinal tubules of calcium hypochlorite with surfactants

Abstract The aim was to assess the physicochemical properties and the penetration into dentinal tubules of calcium hypochlorite solution [Ca(OCl)2], with or without surfactants. The surfactants benzalkonium chloride, cetrimide, Tween 80 and Triton X-100 were mixed at different concentrations with sodium hypochlorite solution (NaOCl), Ca(OCl)2 and distilled water (control). Once the critical micellar concentration (CMC) of the surfactants in Ca(OCl)2 and NaOCl was determined, pH, free chlorine, surface tension and free calcium ions were evaluated. The penetration into dentinal tubules of NaOCl and Ca(OCl)2, with or without benzalkonium chloride and Triton X-100 [surfactants that promoted the lowest surface tension of Ca(OCl)2], was assessed using human premolars stained with crystal violet. The statistical tests were one-way ANOVA and Tukey's post-test, Kruskal-Wallis and Dunn's post-test, two-way ANOVA and Bonferroni's post-test, and t-test; depending on the assay. The addition of surfactants reduced the surface tension of NaOCl and Ca(OCl)2, and did not alter the pH or the free available chlorine of either solution. The addition of all surfactants increased the availability of free calcium ions in Ca(OCl)2, especially benzalkonium chloride. Ca(OCl)2 exhibited lower penetration into dentinal tubules than NaOCl, and the addition of surfactants did not improve the penetration of Ca(OCl)2, but did increase the penetration of NaOCl. It can be concluded that the addition of surfactants to Ca(OCl)2 did not increase the penetration into dentinal tubules, but it did promote lower surface tension, without changing the pH or free available chlorine values, and higher availability of free calcium ions in Ca(OCl)2.

Resumo O objetivo foi avaliar as propriedades físico-químicas e a penetrabilidade nos túbulos dentinários da solução de hipoclorito de cálcio [Ca(OCl)2], com ou sem surfactantes. Os surfactantes cloreto de benzalcônio, cetrimida, Tween 80 e Triton X-100 foram misturados em diferentes concentrações com a solução de hipoclorito de sódio (NaOCl), Ca(OCl)2 e água destilada (controle). Uma vez determinada a concentração micelar crítica (CMC) dos surfactantes em Ca(OCl)2 e NaOCl, foram avaliados o pH, cloro livre, tensão superficial e íons de cálcio livre. A penetrabilidade nos túbulos dentinários de NaOCl e Ca(OCl)2, com ou sem cloreto de benzalcônio e Triton X-100 [surfactantes que promoveram a menor tensão superficial de [Ca(OCl)2] foi avaliada utilizando pré-molares humanos corados com cristal violeta. Os testes estatísticos foram ANOVA de uma via e pós-teste de Tukey, Kruskal-Wallis e pós-teste de Dunn, ANOVA de duas vias e pós-teste de Bonferroni, e teste t; dependendo do ensaio. A adição de surfactantes reduziu a tensão superficial do NaOCl e Ca(OCl)2, e não alterou o pH ou cloro livre das soluções. A adição de todos os surfactantes aumentou a disponibilidade de íons de cálcio livre de Ca(OCl)2, principalmente o cloreto de benzalcônio. Ca(OCl)2 apresentou menor penetrabilidade nos túbulos dentinários do que NaOCl, e a adição de surfactantes não aumentou a penetrabilidade de Ca(OCl)2, mas aumentou a penetrabilidade de NaOCl. Pode-se concluir que a adição de surfactantes no Ca(OCl)2 não aumentou a penetrabilidade nos túbulos dentinários, mas promoveu menor tensão superficial, sem alterar os valores de pH ou cloro livre, e maior disponibilidade de íons de cálcio livre em Ca(OCl)2.

Different formulations of peracetic acid: effects on smear layer removal, dentine erosion, cytotoxicity and antibiofilm activity

Abstract Objective: To assess the effects of different peracetic acid (PAA) formulations on smear layer (SL) removal, dentine erosion, cytotoxicity, and antibiofilm activity. Methodology: SL removal and dentine erosion were assessed using 90 premolars, distributed into six groups, according to final irrigation: PAA formulations (1% Sigma, 1% Bacterend OX, 1% Arposept, and 0.09-0.15% Anioxyde), 17% ethylenediaminetetraacetic acid (EDTA), and water (control). Cytotoxicity was assessed by methyl-thiazol-tetrazolium (MTT) and neutral red assays. Antibacterial and antibiofilm effectiveness was evaluated against Enterococcus faecalis. For cytotoxicity and antibiofilm activity assessment, the 2.5% NaOCl was also included. Results: EDTA, Sigma, and Bacterend OX removed more SL than Arposept, Anioxyde, and water (p<0.05). EDTA caused more severe dentine erosion than Sigma and Bacterend OX (p<0.05). Sigma and Bacterend OX had higher cytotoxicity than the other solutions (p<0.05). NaOCl, Bacterend OX, Sigma, and Anioxyde significantly reduced E. faecalis colony-forming units (CFU) (p<0.05). The 2.5% NaOCl solution promoted greater biofilm biomass reduction (p<0.05) than the other solutions. All PAA formulations promoted greater biomass reduction than 17% EDTA (p<0.05). Conclusions: Although Sigma and Bacterend OX had higher cytotoxicity, they had a SL removal capability similar to that of EDTA, were as effective as NaOCl against E. faecalis biofilm, and promoted less dentine erosion than EDTA. Arposept and Anioxyde failed to remove the SL, had lower cytotoxicity, and showed less bacterial activity than NaOCl.

Management of Tooth Discoloration after Orthognathic Surgery Complications: Report of Two Cases

ABSTRACT: Orthognathic surgery is performed for the correction of craniofacial discrepancies. However, complications, such as tooth discoloration are possible. This case report presents two patients who underwent bilateral sagittal split ramus osteotomy associated with segmental Le Fort I osteotomy and genioplasty. During surgeries, the apical region of anterior teeth was accidentally injured in both cases. After three-week surgery follow-up, the injured teeth showed a change in color to dark pink. In both teeth, the root canal treatment was performed followed by the non vital tooth bleaching. Three sessions were necessary to achieve a significant color change of the teeth. The two-year follow-up showed that both teeth preserved an acceptable color. It was concluded that tooth discoloration after orthognathic surgery is a possible complication, which could be overcome following a conservative approach. Additionally, patients should be informed preoperatively.

RESUMEN: La cirugía ortognática es comúnmente realizada para corregir las discrepancias cráneo-faciales. Sin embargo, se pueden producir complicaciones tales como la pigmentación dentaria. Este reporte de casos presenta a dos pacientes que fueron sometidos osteotomía sagital bilateral de la rama mandibular asociada a osteotomía segmentaria Le Fort I y genioplastía. Durante la fase quirúrgica, la región apical de dientes anteriores fueron accidentalmente dañados en ambos casos. Después de tres semanas de seguimiento de la cirugía, los dientes afectados mostraron un cambio de color a rosado oscuro. Se realizó el tratamiento de conductos seguido de aclaramiento interno en ambas piezas dentarias. Fueron necesarias tres sesiones para lograr un cambio de color significativo. El seguimiento de dos años mostró que ambos dientess conservaron un color aceptable. En conclusión, la pigmentación dentaria después de la cirugía ortognática es una posible complicación, sin embargo, puede ser tratada por medio de un enfoque conservador. Además, los pacientes deben ser informados antes de la cirugía.

Influence of voxel size on dentinal microcrack detection by micro-CT after root canal preparation

Abstract The aim of this study was to assess the influence of micro-computed tomography (micro-CT) voxel size on dentinal microcrack detection after root canal preparation using rotary heat-treated nickel-titanium files. Curved mesial root canals (n = 24) of mandibular molars were prepared using ProDesign Logic 30/.05 (PDL) or HyFlex EDM 25/.08 (HEDM). The specimens were scanned by micro-CT at 5 μm voxel size before and after root canal preparation. The percentage of microcracks was evaluated in images at 5, 10 and 20 μm voxel size, by two examiners at two moments. The Kappa and McNemar tests (α = 0.05) were used. The percentage of dentinal microcracks was similar before and after PDL and HEDM preparations, at 10 and 20 μm (p > 0.05). HEDM showed a higher percentage of dentinal microcracks in the middle third at 5 μm after preparation (p < 0.05). The detection of dentinal microcracks before and after instrumentation using PDL was more accurate at 5 μm than at 20 μm, in all thirds (p < 0.05). Within the limitations of this ex vivo study, as expected, the results showed that different resolutions influence the micro-CT analysis of microcracks. The highest accuracy in detecting microcracks was observed for analyses performed at 5 μm voxel size. HyFlex EDM caused even more microcracks to develop in the middle third, detectable only by visualization of images made at 5 μm voxel size.

Radiopacity of endodontic materials using two models for conversion to millimeters of aluminum

Abstract The aims of the present study were to compare conventional radiography, radiographs digitized with a scanner or photographic camera, and digital radiography, used to evaluate the radiopacity of endodontic materials, and to compare the accuracy of linear and quadratic models used to convert radiopacity values to equivalent millimeters of aluminum (mm Al). Specimens of AH Plus, Endofill, Biodentine and BioMTA materials (n = 8) were radiographed next to an aluminum step-wedge using radiographic films and digital radiography systems (FONA CMOS sensor, Kodak CMOS sensor and photosensitive phosphor plate-PSP). Conventional radiographs were digitized using a scanner or photographic digital camera. Digital images of all the radiographic systems were evaluated using dedicated software. Optical density units (ODU) of the specimens and the aluminum step-wedge were evaluated by a photo-densitometer (PTDM), used in conventional radiographs. The radiopacity in equivalent mm Al of the materials was determined by linear and quadratic models, and the coefficients of determination (R2) values were calculated for each model. Radiopacity of the materials ranged from -9% to 25% for digital systems and digitized radiographs, compared to the PTDM (p < 0.05). The R2 values of the quadratic model were higher than those of the linear model. In conclusion, the FONA CMOS sensor showed the lowest radiopacity variability of the methodologies used, compared with the PTDM, except for the BioMTA group (higher than PTDM). The quadratic model showed higher R2 values than the linear model, thus indicating better accuracy and possible adoption to evaluate the radiopacity of endodontic materials.

In Vitro Cytotoxicity Evaluation of Three Root-End Filling Materials in Human Periodontal Ligament Fibroblasts

Abstract The aim of this study was to evaluate in vitro the cytotoxicity on human periodontal ligament fibroblasts of three root-end filling materials: MTA Angelus(r), EndoSequence Root Repair Material Putty(r) and Super EBA(r). A primary culture of human periodontal ligament fibroblasts was previously obtained in order to evaluate the cytotoxicity of the three extracts from the root-end filling materials after 2 and 7 days of setting. Serial dilutions of these extracts (1:1, 1:2, 1:4 and 1:8) were evaluated at 1, 3 and 7 days using the methyl-thiazol-tetrazolium (MTT) colorimetric assay. Cell viability was evaluated as percentage of the negative control group, which represented 100% cell viability. Statistical analyses were done with t-test, ANOVA and Kruskal-Wallis test at a significance level of 5%. It was found that the main difference among root-end filling materials was in the higher dilutions (p<0.05), but there was a similar behavior in lower dilutions (p>0.05). Cell viability of MTA Angelus(r) was superior for 2-day setting (p<0.05), compared with the other two root-end fillings. There were no statistically significant differences between 7-day set MTA Angelus(r) and EndoSequence Root Repair Material Putty(r). Super EBA(r) showed the lowest percentage of cell viability at higher dilutions (p<0.05). Therefore, MTA Angelus(r) and EndoSequence Root Repair Material Putty(r) were less cytotoxic in the highest dilution (1:1) compared with Super EBA(r).

Resumo O objetivo deste trabalho foi avaliar in vitro a citotoxicidade em fibroblastos do ligamento periodontal humano de três cimentos de retrobturação: MTA Angelus(r), EndoSequence Root Repair Material Putty(r) e Super EBA(r). Uma cultura de fibroblastos primários do ligamento periodontal humano foi obtida anteriormente a fim de avaliar a citotoxicidade dos três extratos dos cimentos de retrobturação após 2 e 7 dias de endurecimento. As diluições em série destes extratos (1:1, 1:2, 1:4 e 1:8) foram avaliados em 1, 3 e 7 dias empregando o ensaio colorimétrico metil-tiazol-tetrazólio (MTT). A viabilidade celular foi calculada em base da porcentagem do grupo de controle negativo, que representou 100% de viabilidade de células. As análises estatísticas foram realizadas com o teste t, ANOVA e teste de Kruskal-Wallis a um nível de significância de 5%. Verificou-se que a principal diferença entre os cimentos de retrobturação estava nas diluições mais elevadas (p<0,05) e houve um comportamento semelhante nas diluições mais baixas (p>0,05). A viabilidade celular dos fibroblastos do ligamento periodontal humano foi superior para MTA Angelus(r) de 2 dias de endurecimento (p<0,05), em comparação com os outros materiais de retrobturação. Não houve diferença significante entre MTA Angelus(r) e EndoSequence Root Repair Material Putty(r) de 7 dias de endurecimento. Super EBA(r) mostrou a menor percentagem da viabilidade celular nas diluições mais altas (p<0,05). Portanto, os cimentos de retrobturação MTA Angelus(r) e EndoSequence Root Repair Material Putty(r) foram menos citotóxicos na diluição mais alta (1:1) em comparação com Super EBA(r).

Agentes hemostáticos en cirugía periapical. Revisión de literatura / Hemostatic agents in apical surgery. A review

La zona periapical es una región altamente vascularizada, y exhibe una gran tendencia a la hemorragia, especialmente en presencia de tejido granulomatoso, que suele acompañar las patologías perirradiculares. Esto representa para el clínico un aspecto de suma importancia, ya que solo mediante un campo seco se obtendrá un campo operatorio efectivamente visible que le permita intervenir adecuadamente. Es necesario evaluar consideraciones pre-quirúrgicas y quirúrgicas tales como la historia médica del paciente, así como la manipulación de los tejidos antes de la elección del agente hemostático que se opte por conveniente. Los agentes hemostáticos presentan características que los hacen particularmente muy distintos unos de otros, tanto en su presentación como en su manejo operatorio. La presente revisión bibliográfica describirá y analizará los principales agentes hemostáticos que se encuentran actualmente disponibles en el mercado y su impacto en la cirugía periapical contemporánea...

The apical area is a highly vascular region, and exhibits a tendency to hemorrhage, especially in presence of granulation tissue that usually is present in periradicular pathologies. This is highly important for the clinician, because only with a dry field can be obtained a visible operative field that allows a suitable surgery. It is necessary to assess pre-surgical and surgical considerations such as medical history, as well as tissue manipulation before the election of a hemostatic agent. Hemostatic agents have characteristics that make them particularly very different from each other, both presentation and clinical management. The aim of this review is to describe and discuss the most common hemostatic agents available and their impact on contemporary apical surgery...

Una visión del reimplante intencional como alternativa a la exodoncia dentaria / A view of intentional replantation as alternative to tooth extraction

La filosofía conservadora es lo más importante en la práctica odontológica contemporánea. No sólo implica la conservación de la estructura dentaria, sino también la preservación de los tejidos circundantes. El reimplante intencional está indicado en casos donde realizar un tratamiento de conductos de manera adecuada es sumamente difícil, o cuando una cirugía apical puede verse comprometida por distintos motivos. La presente revisión bibliográfica abordará las indicaciones, contraindicaciones, principios y técnica de este procedimiento quirúrgico para-endodóntico. Asimismo, se discutirá su conveniencia como opción conservadora antes de la extracción dentaria...

A conservative philosophy is the most important in contemporary dental practice. It involves not only the conservation of tooth structure, but also the preservation of the surrounding tissues. Intentional replantation is indicated in cases where a proper root canal is extremely difficult, or when an apical surgery may be compromised for various reasons. This literature review will address the indications, contraindications, and technical principles of this paraendodontic surgical procedure. Also, will discuss its feasibility as conservative option before tooth extraction...

Uso de barreras apicales y apexificación en endodoncia / Apical barriers and apexification in endodontics

Las barreras apicales son un recurso muy eficaz en el tratamiento de piezas dentales que se encuentran con las raíces incompletamente desarrolladas. Sin embargo, es necesario considerar algunos parámetros, los cuales están directamente relacionados con la terapia radicular indicada y éstos serán discutidos en el presente artículo. La ausencia de una constricción natural, indiferentemente de la etiología, hace que el ápice radicular represente un desafío para el profesional, sobre todo en la obturación, debido a que un foramen abierto no proporciona una barrera anatómica. La presente revisión de la literatura incluye el desarrollo radicular y el impacto de cualquier injuria en dientes con ápices incompletamente desarrollados, así como las opciones de tratamiento disponibles según el diagnóstico pulpar y periapical obtenido.

Apical barriers are a very effective resource in the treatment of incomplete root development teeth, however, it is necessary to consider parameters, which are directly associated to a pertinent root canal therapy, and will be discussed in this article. A natural constriction absence, regardless of the etiology, causes that root apex represents a challenge to the professional, even more during root channel filling, because an open foramen does not provide an anatomic barrier. This literature review includes root development and the impact of injuries on teeth with incomplete root development, as well as treatment options available according to the pulpal and periapical diagnosis.