Continuous Wave of Condensation Improves the Filling of Curved Canals: a Micro-CT Study / La condensación de onda contínua mejora el selle de canales curvos: un estudio de micro-CT

Abstract The aim of this study was to compare the filling capacity in curved root canal using a new continuous wave of condensation technique (Termo Pack II, Easy Dental Equipments, Brazil) or lateral compaction. The percentage of voids in the filling of mesial root canals of mandibular molars was assessed by micro-computed tomography (micro-CT). Mesial root canals (n=24) of mandibular molars with a degree of curvature between 20° and 40° were prepared using rotary system (ProDesign Logic, Easy, Brazil) up to #35, .05 taper. The root canals were filled by using the continuous wave of condensation system or lateral compaction and AH Plus sealer (n=12). Scanning at 9 µm was performed after preparation and after filling by using micro-CT SkyScan 1176. The volumetric percentage of filling material and voids (total length and in each root canal third) were calculated. Data were analyzed using ANOVA/ Tukey and Student's t tests (α=0.05). Before the filling techniques, the root canals volume after preparation was similar (p>0.05). The root canals filled by the continuous wave of condensation technique presented the lowest percentage of voids, and the greatest percentage of filling material in total length and thirds (cervical, middle and apical) (p<0.05). Both techniques were not able of completely filling the root canals. The continuous wave of condensation technique Termo Pack II promoted better root canal filling in curved root canals, when compared with lateral compaction.

Resumen El objetivo de este estudio fue comparar la capacidad de obturación en conductos radiculares curvos utilizando una nueva técnica de condensación de onda continua (Termo Pack II, Easy Dental Equipments, Brasil) vs compactación lateral. El porcentaje de brechas en la obturación de los conductos radiculares mesiales de los molares mandibulares se evaluó mediante microtomografía computarizada (micro-CT). Se prepararon conductos radiculares mesiales (n=24) de molares mandibulares con un grado de curvatura entre 20° y 40° utilizando un sistema rotatorio (ProDesign Logic, Easy, Brasil) al #35, conicidad 0,05. Los conductos radiculares se obturaron utilizando un sistema de condensación de onda contínua o compactación lateral y cemento AH Plus (n=12). Se realizó un escaneo de 9 µm después de la preparación y después de la obturación usando el micro-CT SkyScan 1176. Se calculó el porcentaje volumétrico de material de obturación y vacíos (longitud total y en cada tercio del conducto radicular). Los datos se analizaron utilizando las pruebas ANOVA/Tukey y t de Student (α=0,05). Antes de las técnicas de obturación, el volumen de los conductos radiculares después de la preparación fue similar (p>0,05). Los conductos radiculares obturados con la técnica de condensación por onda contínua presentaron el menor porcentaje de vacíos y el mayor porcentaje de material de obturación en longitud total y en tercios (cervical, medio y apical) (p<0,05). Ambas técnicas no fueron capaces de llenar completamente los conductos radiculares. La técnica de condensación de onda contínua Termo Pack II promovió un mejor relleno del conducto radicular en conductos radiculares curvos en comparación con la compactación lateral.

Immunoexpression of ALDH1A1, FGFR2, CD44 and Caspase-3 in Oral Squamous Cell Carcinoma and Leukoplakia: A pilot study

Current research highlighted the importance to recognize feasible biomarkers for early diagnoses and treatment in oral cancer. Our study analyzed the expression and spatial distribution of ALDH1A1, FGFR2, caspase-3, and CD44 in Oral Squamous Cell Carcinoma (OSCC) and leukoplakia with and without oral mucosal dysplasia. Paraffin-embedded samples of OSCC (n=5), leukoplakia with (n=5) and without (n=5) dysplasia obtained by incisional biopsies were processed using conventional histochemical techniques. Immunohistochemistry was performed using antibodies against ALDH1A1, FGFR2, caspase-3, and CD44. Images of the immunohistochemically stained tissue sections were analyzed according to the intensity of the immunostaining of each marker and classified in Scores. The Kruskal- Wallis test was performed (p≤0.05). Our results demonstrated a statically difference in the expression of all immunomarkers between OSCC and leukoplakia without dysplasia, being more significant in FGFR2 and ALDH1A1. Within the limitations of this study, our data showed that all biomarkers were overexpressed in OSCC and leukoplakia with oral mucosa dysplasia, suggesting that the presence of dysplasia is a significant clinic-pathologic predictor for malignant transformation.

La actual evidencia científica enfatiza la importancia de reconocer biomarcadores viables para el diagnóstico y tratamiento temprano del cáncer oral. Nuestro estudio piloto analizó la expresión y distribución espacial de ALDH1A1, FGFR2, caspasa-3 y CD44 en carcinoma oral de células escamosas (COCE) y en leucoplasia con o sin displasia de la mucosa oral. Las muestras incluidas en parafina de COCE (n=5), con (n=5) y sin (n=5) displasia fueron obtenidas mediante biopsias incisionales, las cuales se procesaron utilizando técnicas histoquímicas convencionales. El análisis inmunohistoquímico se realizó utilizando anticuerpos contra ALDH1A1, FGFR2, caspasa-3 y CD44. Las imágenes de las secciones de cada muestra fueron analizadas según la intensidad de inmunoexpresión de cada marcador y se clasificaron en diferentes escalas (scores). Se realizó la prueba de Kruskal-Wallis (valores de p<0,05). Nuestros resultados demostraron una diferencia estadística en la expresión de todos los inmunomarcadores entre COCE y las muestras con leucoplasia sin displasia, siendo más significativa en FGFR2 y ALDH1A1. Considerando las limitaciones de este estudio, los datos sugieren que la presencia de displasia en la mucosa oral es un importante predictor clínico-patológico de transformación maligna.

Irrigation protocols effects on radicular dentin: Cleaning, disinfection and remaining ultrastructure / Efecto del protocolo de irrigación en la dentina radicular: limpieza, desinfección y ultraestructura remanente

A successful endodontic treatment requires a combination of satisfactory mechanical instrumentation, adequate irrigation protocols, and three-dimensional obturation of the canal system. Irrigation is considered the most critical procedure to ensure cleaning and disinfection. To date, a large variety of irrigants has been proposed. However, sodium hypochlorite (NaOCl) remains the gold standard. In order to achieve complete cleaning and disinfection, final irrigation with EDTA and ultrasonic devices has been used as an ideal protocol. Most endodontic research focuses on the cleaning and antibacterial properties of the irrigant solutions. Recent evidence demonstrated that the irrigation protocols cause erosion, affecting the radicular dentin ultrastructure. This article aims to describe the clinical features of the present knowledge concerning the effect of irrigation protocols on radicular dentin.

Un tratamiento de endodoncia exitoso requiere de una satisfactoria instrumentación mecánica, protocolos de irrigación adecuados y obturación tridimensional del sistema de conductos radiculares. La irrigación se considera el procedimiento más crítico para garantizar la limpieza y desinfección. Hasta la fecha, se ha propuesto una gran variedad de irrigantes. Sin embargo, el hipoclorito de sodio (NaOCl) sigue siendo el estándar de oro. Para lograr una limpieza y desinfección completa, se ha utilizado como protocolo ideal la irrigación final con EDTA y dispositivos ultrasónicos. La mayor parte de la investigación en endodoncia se enfoca en las propiedades antibacterianas y de limpieza de las soluciones de irrigación. Reciente evidencia demostró que los protocolos de irrigación provocan erosión, afectando la ultraestructura de la dentina radicular. Este artículo tiene como objetivo describir algunas consideraciones clínicas del conocimiento actual sobre el efecto de los protocolos de irrigación en la dentina radicular.

Immunohistochemical characterization of stem cell, vascular, neural, and differentiation markers in the apical papilla and dental pulp of human teeth at various stages of root development.

This study aimed to evaluate the expression of several differentiation markers in the apical papilla (AP) and dental pulp (DP) of human permanent teeth. Twenty young human teeth were extracted and classified according to three Moorrees tooth development stages: initial root formation (Ri), root length ½ (R1/2), and root length complete (Rc). Immunohistochemical assays were performed using STRO-1, VEGF Receptor-2, Neurofilament heavy (NFH), and Nestin antibodies and analyzed under light microscopy. Decalcified, formalin fixed paraffin embedded tooth sections stained with hematoxylin and eosin showed an apical cell rich zone between the DP and AP. The AP revealed fewer vascular and cellular components than the DP. STRO-1 was expressed on vascular and neuronal elements beneath the odontoblast (OB) and in the sub-odontoblastic (SOB) zone, and VEGFR-2 positive cells were observed in the endothelium, arterioles, and blood vessels. Neuroepithelial stem cell protein (Nestin) was highly expressed in differentiated odontoblasts in the predentin odontotoblast and odontoblast cell processes. Neurofilament heavy (NFH) was expressed in mature axons throughout the DP. STRO-1 and VEGFR-2 microvascular expression was higher at the stages Ri and R1/2 while STRO-1 and NFH expression showed strong spatial distribution of Rc neuronal elements as compared to Ri and R1/2. Differentiated OB and SOB cells showed Nestin expression, indicating a reservoir of newly differentiated odontoblast-like cells.

Final irrigation protocols affect radicular dentin DMP1-CT expression, microhardness, and biochemical composition.

OBJECTIVE: To evaluate the effect of several final irrigation protocols on radicular dentin microhardness, biochemical composition, and DMP1-CT expression. MATERIALS AND METHODS: A total of 140 single-rooted human teeth were prepared with WaveOne Gold files and randomly distributed into 7 groups (n = 20) according to the final irrigation protocol: distilled water (DW); sodium hypochlorite-EDTA (NaOCl-EDTA); EDTA (EDTA); EDTA-NaOCl (EDTA-NaOCl); EDTA-chlorhexidine (EDTA-CHX); passive ultrasonic irrigation (PUI:NaOCl-EDTA); and PUI:NaOCl-EDTA-NaOCl. Dentin microhardness (n = 10) was evaluated in the root canal lumen using Vickers hardness tester. Immunohistochemical analysis (n = 5) was used to evaluate DMP1-CT expression. Dentin ultrastructure and biochemical composition were evaluated by using Raman and energy dispersive X-ray analysis (EDAX) (n = 5) with a scanning electron microscope (SEM). Analysis of variance (ANOVA) and Tukey test were performed (p˂0.05). RESULTS: Raman spectra of the organic content and DMP1-CT expression were lower at the lumen canal in EDTA-NaOCl, PUI:NaOCl-EDTA, and PUI:NaOCl-EDTA-NaOCl when compared to control (p < 0.05). EDAX showed reduced values for calcium and phosphorus in EDTA-NaOCl, PUI:NaOCl-EDTA, and PUI:NaOCl-EDTA-NaOCl. SEM microphotography's showed completely cleaned dentin, permeable tubules, and dentin erosion, mainly when PUI was used. NaOCl-EDTA presented significantly higher microhardness values than PUI:NaOCl-EDTA-NaOCl (p < 0.05). PUI:NaOCl-EDTA-NaOCl exhibited the lowest Vickers hardness values of all groups. CONCLUSION: The final irrigation protocols that used a final rinse with NaOCl and PUI showed a detrimental effect on radicular dentin DMP1-CT expression, biochemical composition, and microhardness. CLINICAL RELEVANCE: The adequate irrigation protocol could be advantageous to preserve the radicular dentin ultrastructure, promote adequate adhesion, and sustain favorable conditions for biomineralization and regeneration.

Social inequality in incidence and mortality of malignant neoplasms of lip, oral cavity and pharynx: Is Costa Rica an international paradox?

OBJECTIVES: Low socioeconomic position (SEP) has been associated with higher incidences and mortality of lip, oral cavity and pharynx (LOP) cancers in the vast majority of countries with available data. The origins of health inequalities in cancer are socioeconomic, although they vary by time and country. Evidence from Low-and Middle-income Countries (LMICs) remains scarce. This study aims to identify and describe socioeconomic inequalities in LOP cancers incidence and mortality in Costa Rica. The hypothesis tested is that people leaving in low-SEP districts in Costa Rica have greater incidence and mortality rates of lip, oral cavity and pharynx cancers. METHODS: The 10th revision of the International Classification of Diseases (ICD-10) was used to define cancer sites. Data come from a national population-based Cancer Registry with 100% completeness to study incidence. Incidence rate included all new cases of LOP cancer diagnosed from January 1, 2011, and December 31, 2015, for a total of 2 798 517 individuals, 13 832 524 years of follow-up and 601 LOP cases. Mortality rate was extracted from the National Death Index, including 2 739 733 individuals, 23 950 240 person-years of follow-up and 586 LOP cancer deaths, from January 1, 2010, to December 31, 2018. The 2011 Census (with 94% of Costa Rican inhabitants) was used to characterize the urbanicity and wealth of 477 districts. Survival models were performed for both incidence and mortality, allowing to consider existing competitive risks. Cox models were used for incidence, and parametric survival models based on a Gompertz distribution for mortality. RESULTS: The study found that people who lived in the most socioeconomically disadvantaged areas had lower probabilities of developing LOP cancers than people in the richest districts. The same pattern for mortality, however, was not significant. CONCLUSIONS: The hypothesis that incidence and mortality of LOP cancers will show a positive social gradient was not confirmed in this study, contradicting the existing literature. This could be explained by the social distribution of risky health behaviours, more frequent in socially advantaged populations.

Revisión por pares en la publicación científica: recomendaciones desde ODOVTOS / Peer Reviews in Scientific Journals: Recommendations from ODOVTOS

Resumen El proceso editorial de una revista, específicamente la revisión por pares, valida la publicación científica con el respaldo de la experiencia y el conocimiento de los revisores. Sin embargo, a pesar de que existen programas que capacitan en la parte investigativa a los miembros de la comunidad científica, son escasas las herramientas de capacitación para participar en el arbitraje de un manuscrito. El propósito de este artículo es presentar una guía con una serie de recomendaciones sobre cómo un artículo científico debe ser revisado por pares. Se realiza una sumatoria de recomendaciones y criterios que servirán para que los revisores de Odovtos-International Journal of Dental Sciences puedan utilizar como referencia y respaldo para su labor.

Abstract The editorial process of a journal, specifically peer review, validates the scientific publication supported by the experience and knowledge of the reviewers. However, despite the fact that there are programs that instruct members of the scientific community in research, there are few training tools to participate in the arbitration of a manuscript. The purpose of this article was to present a guide with a series of recommendations on how a scientific article should be peer-reviewed. A synopsis of recommendations and criteria is presented and will be used by the reviewers of Odovtos-International Journal of Dental Sciences as a reference to support their work.

Sodium Hypochlorite and Chlorhexidine Downregulate MMP Expression on Radicular Dentin.

OBJECTIVE: Matrix metalloproteinases (MMPs) are present in radicular dentin and can convert structural matrix proteins into signaling molecules; thus, these enzymes play an essential role in dentin biomineralization and tissue regeneration therapies. Their expression on radicular dentin may be affected by the irrigation solutions used during root canal treatments. This study aimed to evaluate the effects of the most common irrigants on radicular dentin MMP expression. MATERIALS AND METHODS: The experimental solutions were distilled water (control), 5% sodium hypochlorite (NaOCl), 18% ethylenediaminetetraacetic acid (EDTA), and 2% chlorhexidine (CHX). Samples were prepared from extracted human teeth. For zymography analysis, root sections were powderized, and dentin proteins were extracted to observe gelatinolytic activity. Root dentin slices were treated with the experimental solutions for immunohistochemical analysis using anti-MMP-2 and anti-MMP-9 antibodies. ANOVA and the Tukey test were performed. RESULTS: Zymograms revealed the presence of MMP-2, MMP-8, and MMP-20 in the control group and the EDTA-treated group. Immunohistochemistry confirmed the presence of MMP-2 and MMP-9 mainly associated with the dentinal tubule lumens and occasionally with intertubular dentin. NaOCl- and CHX-treated groups showed lower expression of MMPs than the control group. Immuno-staining for both proteinases in the EDTA-treated group showed higher expression compared to the other experimental groups. CONCLUSION: Our results showed that most common irrigants affect MMP expression on radicular dentin. Treatment with NaOCl and chlorhexidine resulted in lower expression of MMPs, while EDTA increased their expression in root canal dentin.

Push-Out Bond Strength, Characterization, and Ion Release of Premixed and Powder-Liquid Bioceramic Sealers with or without Gutta-Percha.

OBJECTIVE: To evaluate the push-out bond strength of premixed and powder-liquid bioceramic sealers with or without gutta-percha (GP) cone. MATERIALS AND METHODS: Radicular dentin samples were prepared from 80 single-rooted human teeth. After root canal preparation using ProTaper® and irrigation with NaOCl and EDTA, teeth were divided according to the root canal sealer (n = 20): AH Plus®, EndoSequence® BC Sealer™, ProRoot® Endo Sealer, and BioRoot™ RCS. Samples were randomly divided into two subgroups (n = 10): GP-S: root canal filling using the single-cone technique, or S: filling with only sealer. Specimens were kept at 37°C and 100% humidity in calcium-free PBS for 30 days. The push-out bond strength was measured in MPa. Fractured specimens were observed at 25x to evaluate the type of failure. pH and calcium ion release were measured at different experimental periods. Raman and SEM-EDAX analyses were performed for root canal sealers. Data were analysed using three-way analysis of variance (ANOVA) and post hoc Tukey test at a significance of P < 0.05. RESULTS: Push-out bond strength was greater for samples obturated with only sealers (S) than samples obturated with the single-cone technique (GP-S) (P < 0.05). BioRoot™ RCS had greater bond strength than EndoSequence® BC Sealer™. Adhesive failures between cement and gutta-percha cone (87.5%) were predominant in the GP-S. Cohesive failures were predominant for S (80%). BioRoot™ RCS and ProRoot® ES presented higher alkalinization potential than the premixed sealer (EndoSequence® BC Sealer™). Powder-liquid bioceramic sealers (BioRoot™ RCS and ProRoot® ES) released the highest cumulative amount of calcium (28.46 mg/L and 20.05 mg/L). CONCLUSION: Push-out test without gutta-percha cone presents higher bond strength for bioceramic sealers. Powder-liquid calcium silicate-based sealers present greater bioactivity related to alkalinization potential and calcium ion release.

Ex Vivo Analysis of MTA FLOW® Biomineralization and Push-Out Strength: A Pilot Study / Análisis ex vivo del proceso de biomineralización y resistencia al desplazamiento del MTA FLOW®: Estudio piloto

Abstract: This study evaluated the biomineralization processes and push-out strength of MTA Flow® with radicular dentine in three different consistencies. The push-out test was performed on an ex vivo model, using 2mm thick dentin discs from the middle third of the root with standardized cavities of 1.5 mm. Samples were filled with MTA-Angelus (Angelus Dental, Brazil), Biodentine (Septodont, France), MTA Flow® Putty (Ultradent, USA), MTA Flow® Thick or MTA Flow® Thin. The samples were divided into 3 groups: subgroup 1 (n=5), analysis of the biomineralization process; 2 (n=20), evaluation of the bonding strength and push-out resistance; and 3 (n=5), evaluation of the cement/ dentin interface. The samples filled with Biodentine had a higher precipitation of carbonate apatite. However, there was no significant difference between MTA-Angelus, MTA Flow® Putty, or Thick (p=0.0536), but there was a significant difference in the Thin group (P<0.05). The samples with Biodentine displayed the greatest release of calcium ions. The formation of a partially carbonated intermediate apatite layer was observed in all groups. Zones of biomineralization were observed at the interface but were not continuous. After 72 hours, a significant difference was found between the Biodentine and MTA Flow® Thin groups (p=0.0090) in the push-out test. The samples submerged in phosphate-buffered saline (PBS) for 15 days showed a significant difference between all groups and MTA Flow® Thin (p=0.0147). Putty or Thick consistencies presented a similar bonding strength to MTA-Angelus and Biodentine. MTA Flow® Putty and Thick consistencies show a good adaptation to dentin, similar to MTA-Angelus. However, the thickness of the interface was lower compared to that of Biodentine. MTA Flow® Thin, despite their tubular infiltration, results in gaps and a defective peripheral seal.Therefore, MTA Flow®, in Putty or Thick consistencies, presents a biomineralization process and push-out strength similar to MTA Angelus and Biodentine, however, both characteristics decreases considerably in Thin consistency.

Resumen: El objetivo de este estudio fue evaluar, en un modelo ex vivo, el proceso de biomineralización y fuerza de adhesión del MTA Flow® en sus tres diferentes consistencias por medio de la prueba de resistencia al desplazamiento (Push-out). Se utilizaron discos de dentina de 2mm de espesor del tercio medio radicular con cavidades estandarizadas de 1.5mm de diámetro, las cuales se obturaron con diferentes materiales entre ellos: MTA Angelus (Angelus Dental, Brasil), Biodentine (Septodont, Francia), MTA Flow® Consistencia Putty (Ultradent, E.E.U.U), MTA Flow® Consistencia Thick (Ultradent, E.E.U.U) y MTA Flow® Consistencia Thin (Ultradent, E.E.U.U). Las muestras se sometieron al proceso de biomineralización y a pruebas de Push-out. Las muestras obturadas con Biodentine promovieron una mayor precipitación de apatita carbonatada, sin embargo, no se presentó diferencia estadística significativa con respecto al MTA Angelus, MTA Flow® Putty ni Thick (p=0.0536). No obstante, si presentó una diferencia significativa con respecto al grupo de MTA Flow® consistencia Thin (P<0.05). Las muestras con Biodentine presentaron la mayor liberación de iones calcio. De acuerdo a las pruebas de resistencia al desplazamiento, a las 72 horas post-obturación, solamente se encontró diferencia significativa entre las muestras obturadas con Biodentine y las correspondientes al MTA Flow consistencia Thin (p=0.0090), sin embargo las muestras sumergidas 15 días en PBS presentaron diferencia significativa entre todos los grupos con respecto al MTA Flow Thin (p=0.0147). En general se observaron zonas de biomineralización en la interface, sin embargo, no fueron continuas. Se concluye que el MTA Flow en consistencia Putty o Thick presenta un proceso de biomineralización y una resistencia al desplazamiento similar al MTA Angelus y al Biodentine, sin embargo, esta última disminuye considerablemente en presentación Thin.

COVID-19: Perspectives on the Pandemic and its Incidence in Dentistry / COVID-19: Perspectivas sobre la pandemia y su incidencia en odontología

Abstract In December 2019, a novel coronavirus disease (COVID-19) presenting with pneumonia emerged in Wuhan, China. The ongoing spread of COVID-19 worldwide is creating enormous uncertainty. In particular, the dental profession is facing a major challenge. Due to the characteristics of dental settings, the risk of cross-infection is elevated between patients and dental staff. The present review aimed to briefly discuss the overview of the disease, including the basic science, epidemiology, symptoms, routes of transmission and several topics that the authors believe are binding and relevant to the dental practice. The guidelines adopted by governments and international organizations also address all dental associations to protect the health of the community and to contain the spread of COVID-19 infection until a vaccine or an effective/validated treatment becomes available.

Resumen En diciembre del 2019, surgió una nueva enfermedad por coronavirus (COVID-19) que se presentó como una neumonía con etiología desconocida en Wuhan, China. La propagación continua de COVID-19 en todo el mundo está creando una enorme incertidumbre. En particular, la profesión dental se enfrenta a un gran desafío. Debido a las características de los consultorios dentales, el riesgo de infección cruzada es elevado entre los pacientes y el personal. La presente revisión tuvo como objetivo discutir brevemente la visión general de la enfermedad, incluyendo conceptos de ciencia básica, la epidemiología, vías de transmisión, síntomas y varios temas que los autores consideran vinculantes y relevantes para la práctica dental. Las directrices adoptadas por los gobiernos y las organizaciones internacionales también involucran a todas las asociaciones dentales para proteger la salud de la comunidad y contener la propagación de la infección por COVID-19 hasta que una vacuna o un tratamiento eficaz/validado esté disponible.

Ex Vivo Evaluation of a Restoration Protocol for Teeth with Simulated Incomplete Rhizogenesis / Evaluación ex vivo de un protocolo de restauración para dientes con rizogénesis incompleta simulada

Abstract: The use of phosphate buffered saline (PBS) as an intracanal medication triggers a biomineralization process within mineral trioxide aggregate (MTA) apical plugs during the apexification process in teeth with incomplete rhizogenesis. However, no consensus is available in the literature regarding a restorative protocol for this type of treatment. Thus, the objective of this study was to use scanning electron microscopy (SEM) to evaluate the processes of biomineralization and adhesion in a restorative protocol for teeth with simulated incomplete rhizogenesis. Methodology: Root sections with a thickness of 2mm and cavities with a diameter of 2mm were used. The sections were randomly prepared and filled with the following materials: Group 1 (n=12), ProRoot MTA; and Group 2 (n=12): MTA Exp. Subsequently, the samples were immersed in PBS for 35 days. Every 5 days, the PBS was replaced, and the precipitates were collected, dried, and weighed. Two samples from each group were analyzed by SEM. Moreover, 24 single-rooted teeth were standardized, incomplete rhizogenesis was simulated, and 5-mm-long apical plugs were created with Pro Root MTA. As an intracanal medication, PBS was used for different periods of time: Group 1:48 h; Group 2:7 days; and Group 3:15 days. Then, fiberglass posts were cemented with the REBILDA® Post System. The samples were prepared and analyzed by SEM. Results: ProRoot MTA and MTA Exp effectively promoted the formation of carbonated apatite precipitates and biomineralization with dentin. ProRoot MTA yielded more carbonated apatite precipitates compared to MTA Exp (p=0.0536). The use of PBS as an intracanal medication for 7 and 15 days promoted intratubular mineralization (MIT), and treatment for 15 days was more effective (p < 0.05). The REBILDA® Post System effectively promoted the microimbrication of the adhesive system and the formation of resinous tags with lateral adhesive branches. Conclusion: Apexification with MTA associated with the use of PBS as an intracanal medication for 15 days, in addition to the use of the REBILDA® Post System, seems to be a feasible restorative protocol.

Resumen: El uso de solución salina tamponada con fosfato (PBS) como medicamento intracanal desencadena un proceso de biomineralización en los plugs apicales con agregado de trióxido mineral (MTA) durante el proceso de apexificación en dientes con rizogénesis incompleta. Sin embargo, no hay consenso disponible en la literatura sobre un protocolo restaurador para este tipo de tratamiento. Por lo tanto, el objetivo de este estudio fue utilizar microscopía electrónica de barrido (MEB) para evaluar los procesos de biomineralización y adhesión en un protocolo restaurador para dientes con rizogénesis incompleta simulada. Metodología: Se utilizaron secciones de raíz con un espesor de 2mm y se realizaron cavidades con un diámetro de 2 mm. Las cavidades en las secciones se obturaron con: Grupo 1 (n=12), ProRoot MTA; y Grupo 2 (n=12): MTA Exp. Posteriormente, las muestras se sumergieron en PBS durante 35 días. Cada 5 días, se reemplazó el PBS y se recogieron los precipitados, se secaron y pesaron. Dos muestras de cada grupo fueron analizadas por MEB. Además, se estandarizaron 24 dientes de raíz única, se simuló la rizogénesis incompleta y se crearon tapones apicales de 5mm de longitud con Pro Root MTA. Como medicamento intracanal, se utilizó PBS durante diferentes períodos de tiempo: Grupo 1:48 h; Grupo 2:7 días; y Grupo 3:15 días. Posteriormente, los postes de fibra de vidrio se cementaron con el sistema de postes REBILDA®. Las muestras fueron preparadas y analizadas por MEB. Resultados: ProRoot MTA y MTA Exp promovieron efectivamente la formación de precipitados de apatita carbonatada y la biomineralización con dentina. ProRoot MTA produjo más precipitados de apatita carbonatada en comparación con MTA Exp (p=0.0536). El uso de PBS como medicamento intracanal durante 7 y 15 días promovió la mineralización intratubular (MIT), siendo el tratamiento durante 15 días más efectivo (p <0.05). El sistema de postes REBILDA® promovió efectivamente la microimbricación del sistema adhesivo y la formación de tags resinosos. Conclusión: La apexificación con MTA asociada con el uso de PBS como medicación intracanal durante 15 días, además del uso del sistema de postes REBILDA®, parece ser un protocolo factible y eficaz en este tipo de tratamientos.

Non-Collagenous Dentin Protein Binding Sites Control Mineral Formation during the Biomineralisation Process in Radicular Dentin.

The biomineralisation of radicular dentin involves complex molecular signalling. Providing evidence of protein binding sites for calcium ions and mineral precipitation is essential for a better understanding of the remineralisation process. This study aimed to evaluate the functional relationship of metalloproteinases (MMPs) and non-collagenous proteins (NCPs) with mineral initiation and maturation during the biomineralisation of radicular dentin. A standardized demineralisation procedure was performed to radicular dentin slices. Samples were remineralised in a PBS-bioactive material system for different periods of time. Assessments of ion exchange, Raman analysis, and energy dispersive X-ray analysis (EDAX) with a scanning electron microscope (SEM) were used to evaluate the remineralisation process. Immunohistochemistry and zymography were performed to analyse NCPs and MMPs expression. SEM evaluation showed that the mineral nucleation and growth occurs, exclusively, on the demineralised radicular dentin surface. Raman analysis of remineralised dentin showed intense peaks at 955 and 1063 cm-1, which can be attributed to carbonate apatite formation. Immunohistochemistry of demineralised samples revealed the presence of DMP1-CT, mainly in intratubular dentin, whereas DSPP in intratubular and intertubular dentin. DMP1-CT and DSPP binding sites control carbonate apatite nucleation and maturation guiding the remineralisation of radicular dentin.

Incidence of root resorption after concussion, subluxation, lateral luxation, intrusion, and extrusion: a systematic review.

OBJECTIVE: Traumatic dental injuries often affect the dental hard tissues, periodontal tissues, and dental pulp. Root resorption (RR) is a significantly concerning phenomenon that could lead to loss of the traumatized tooth. The purpose of this systematic review was to analyze the incidences of different types of RR after concussion, subluxation, lateral luxation, intrusive luxation, and extrusive luxation. MATERIAL AND METHODS: Seven databases were electronically and manually searched for the identification of observational studies that evaluated the incidence of RR after luxation injuries. Following study selection, data extraction, and risk of bias assessment through MAStARI checklist, the GRADE quality of available evidence was assessed. RESULTS: In total, 14 studies were included in the present systematic review. Ten and four studies presented a moderate and low RoB, respectively, and the overall GRADE quality of evidence was "very low" for all outcomes. The highest incidence rates of RR were observed for teeth with intrusive luxation, followed by those with extrusive luxation, lateral luxation, subluxation, and concussion. In general, the most common type of RR documented for all injuries was inflammatory RR, followed by replacement RR, surface RR, and internal RR. CONCLUSIONS: Our findings suggest that RR most commonly occurs in association with intrusive luxation and by inflammatory RR. Awareness regarding the incidence of RR after injuries is useful for clinicians to minimize the risk and severity of its occurrence, because a late diagnosis of RR may limit treatment alternatives and result in tooth loss. CLINICAL RELEVANCE: Knowledge about the incidence of RR in teeth with concussion and different types of luxation injuries can ensure appropriate follow-up protocols and favorable outcomes.

Incidence of Root Resorption after the Replantation of Avulsed Teeth: A Meta-analysis.

INTRODUCTION: An avulsion injury is a serious trauma to pulp and periodontal tissues. After avulsion and replantation, teeth are at risk of infection and root resorption, which may affect treatment outcome and survival rate. Thus, the purpose of this systematic review was to evaluate the incidence of root resorption after the replantation of avulsed teeth. METHODS: Two reviewers searched 7 electronic databases for observational studies involving human subjects that evaluated the incidence of root resorption after tooth avulsion. Risk of bias (RoB) was evaluated using the Meta-Analysis of Statistics Assessment and Review Instrument, and the quality of available evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation tool. RESULTS: Of the 1507 articles, 23 met the inclusion criteria. A meta-analysis was conducted and showed that the incidence of internal root resorption was 1.2% (95% confidence interval [CI], 0.02-5.50). Regarding external root resorption, the incidence of surface root resorption was 13.3% (95% CI, 6.21-22.62), that of inflammatory root resorption was 23.2% (95% CI, 13.94-34.19), and that of replacement root resorption was 51.0% (95% CI, 40.10-62.00). Two studies presented a high RoB, 16 had a moderate RoB, and 11 had a low RoB. The overall level of evidence identified was very low. CONCLUSIONS: The incidence of root resorption after avulsion and replantation in descending order was replacement root resorption > inflammatory root resorption > surface root resorption > internal root resorption.

Effect of temperature and seven storage media on human periodontal ligament fibroblast viability.

BACKGROUND/AIM: Natural resources, such as coconut water, propolis, and egg whites, have been examined as possible storage media for avulsed teeth. However, there is a lack of research focused on the efficacy of these three products together compared with Hank's balanced salt solution and milk. The aim of this study was to evaluate the capacity of seven storage media to maintain the viability of human periodontal ligament fibroblasts (PDLFs). MATERIAL AND METHODS: PDLFs were kept at 5°C and 20°C, in skimmed milk (SMilk), whole milk (WMilk), recently prepared Hank's balanced salt solution (HBSS), Save-A-Tooth® system's HBSS (Save), natural coconut water (Coconut), Propolis, and egg white (Egg) for 3, 6, 24, 48, 72, 96, and 120 h, through the analysis of tetrazolium salt-based colorimetric (MTT) assay. RESULTS: At 5°C, SMilk and WMilk were better than HBSS in maintaining cell viability, from 24 h onward. At 20°C, HBSS was the best storage medium at 96 and 120 h. At both temperatures, from 6 h onward, Coconut, Propolis and Egg were less effective than SMilk, WMilk, and HBSS. In general, the performance of Coconut, Propolis and Egg were not influenced by storage temperature. However, the lowest temperature undermined the effectiveness of HBSS from 24 h and favored SMilk and WMilk, from 96 and 48 h onward, respectively. Save and water were the worst storage media. CONCLUSION: SMilk was the best storage medium, followed by WMilk and HBSS. Coconut, Propolis, and Egg can be indicated for the conservation of PDLF up to 3 h. The lower temperature (5°C) undermined the effectiveness of HBSS and favored SMilk and WMilk.