Cav1.2 regulated odontogenic differentiation of NG2+ pericytes during pulp injury.

NG2+ pericytes, as the possible precursor cells of mesenchymal stem cells (MSCs), have drawn attention due to their ability to differentiate into odontoblasts. Cav1.2 is involved in the differentiation process of stem cells, but its role in the differentiation of NG2+ pericytes is not clear. The aim of the present study was to examine the role of Cav1.2 in the differentiation of NG2+ pericytes into odontoblasts. NG2+ pericytes were obtained from human dental pulp cells by magnetic-activated cell sorting. During the odontogenic differentiation of NG2+ pericytes, the effects of the Cav1.2 inhibitors, nimodipine and Cav1.2 knockdown shRNA, were analyzed by real-time polymerase chain reaction and alizarin red staining. NG2CreERT2/Rosa26-GFP lineage-tracing mice were established to further investigate the roles of NG2+ pericytes and Cav1.2 in incisor self-repair after injury in vivo. At 10 min, 1 day, and 3 days after pulp injuries in transgenic mice, NG2-GFP+ and Cav1.2 immunofluorescence co-staining was performed on the incisors. Nimodipine treatment and Cav1.2 knockdown showed similar inhibition of calcium nodule formation and mRNA levels of osteogenic markers (DSPP, DMP1, and Runx2, p < 0.05). NG2+ pericytes migrated from their inherent perivascular location to the odontoblast layers after pulp injury. Cav1.2 showed a similar response pattern as NG2+ pericytes and gradually returned to normal levels. In addition, many co-stained areas of Cav1.2 and NG2+ pericytes, both near the perivascular and odontoblast layers, were observed. These results indicate that Cav1.2 played a vital role in the odontogenic differentiation of NG2+ pericytes, and that it might be closely linked to the NG2+ pericytes-mediated repair of dental pulp injury in vivo.

Root Fractures in the Primary Teeth and Their Management: A Scoping Review.

(1) Background: Traumatic dental injuries constitute a major global health problem. Primary deciduous teeth of the upper frontal group are frequently affected by trauma, especially at an early age. It is important to treat primary traumatic injuries because early tooth loss can lead to aesthetic and functional alterations. The most common injuries are extrusion, lateral luxation, and intrusion. Root fracture is a less common complication that can lead to tooth extraction if not properly diagnosed and managed. However, there are a lack of data regarding primary root fracture treatment. The literature was reviewed to study the current knowledge on the treatment of these injuries, and to propose an operative protocol based on the results obtained. (2) Methods: A literature search was performed on Web of Science, PubMed/MEDLINE, and SCOPUS. The research focused on the following features: age of the patient; localization of the root fracture and type of displacement suffered (intrusive, extrusive, or lateral); type of emergency treatment or diagnostic test performed and their compliance with IADT guidelines; follow-up duration. (2) Results: Only 8 articles fully met the inclusion criteria, with a total of 46 patients and 62 root fractures. Out of a total of 62 root fractures, regarding only upper incisors, the most common treatment was splinting (n = 39) for a period ranging from 3 weeks to 3 months (with an average of six weeks). No treatment was performed for 23 of the root fractures. The splinting performed in most of the included cases was semi-rigid, with the splint held in place using a composite resin material. An orthodontic splint using brackets and 0.5 mm stainless steel wire was used in only in one study. (4) Conclusions: We deduced that the root fracture of primary teeth is a rare traumatic dental injury that can cause numerous complications, such as eruptive problems in the permanent teeth. Correct radiological diagnosis, immediate repositioning and semi-rigid splinting could be conservative methods to prevent premature tooth loss in very young patients.

Root Fracture and Extrusive Luxation in Primary Teeth and Their Management: A Case Report.

BACKGROUND: Extrusion, lateral luxation, and intrusion are among the most serious types of dental trauma. Only a few studies have specifically focused on extrusion; the present one was aimed at reporting a case of domestic traumatic dental injury to primary tooth and describing the measures taken in managing the trauma in order to avoid future consequences to the underlying permanent tooth germ. CASE REPORT: A 3.5-year-old boy reported a dental injury with extrusion and root fracture of deciduous tooth 5.1. After intraoral and radiographic evaluation, the element was repositioned and stabilized by an orthodontic flexible splint attached to the adjacent teeth. Several follow-up checkups were made and showed good healing of the tissues and physiological exfoliation of the tooth, with a healthy and unaffected corresponding central permanent incisor. CONCLUSION: This case report strengthens the importance of well-timed diagnosis and treatment and of regular follow-up of traumatized teeth as they may affect both dentitions with a negative impact on Oral Health-Related Quality of Life. Conservative treatment should be taken into consideration when possible, being in some cases more appropriate.

Comportamiento de las enfermedades pulpares en la Escuela "Arides Estévez", La Habana, 2009 / Pulp diseases behavior in "Arides Estévez" school, La Habana, 2009

Introducción: como consecuencia de la acción de la caries dental sobre los dientes de la cavidad oral, la pulpa se convierte en un albergue de bacterias y sus subproductos, lo que origina la enfermedad pulpar. La respuesta a estas infecciones puede dar lugar a enfermedades agudas o crónicas que constituye la mayoría de las urgencias estomatológicas en Cuba. Objetivo: caracterizar el comportamiento de las enfermedades pulpares; así como el proceder terapéutico frente a las mismas en la escuela Arides Estévez. Material y Métodos: se realizó un estudio descriptivo transversal con 162 estudiantes quienes acudieron a la consulta estomatológica de dicha escuela y fueron diagnosticados con algún tipo de enfermedad pulpar, en el período comprendido entre octubre de 2008 a diciembre de 2009. Resultados: el 69,1 por ciento de los afectados por enfermedades pulpares fueron del sexo masculino y el grupo etario más afectado fue el de 19-25 años con 65,4 por ciento. La pulpitis transitoria afectó a 50 por ciento de los casos, mientras que la caries dental estuvo presente en 46,9 por ciento de los mismos. El 60,4 por ciento de los pacientes recibieron tratamiento conservador. Conclusiones: la enfermedad pulpar más frecuente en la población estudiada es la pulpitis reversible y de esta la transitoria; las edades más afectadas están entre los 19 y 25 años, y los varones son los más aquejados. La caries dental, seguida de las obturaciones deficientes, es la causa de la mayor cantidad de lesiones pulpares. El tratamiento conservador es la terapia más usada en estos casos(AU)

Introduction: as consequence of action of dental caries over the teeth in oral cavity, the pulp becomes a shelter of bacteria and their products resulting in pulp disease. The respond to these infections can be acute or chronic constituting major cause of stomatological emergencies in Cuba. Objective: to characterize the behaviour of pulp diseases, as well as the therapeutic procedure against them at the Arides Estévez school. Material and Methods: a cross-sectional study was performed with 162 students who attended the school dentist consultation and were diagnosed with some type of pulp´s disease in the period from October 2008 to December 2009. Results: 69, 1 percent of affected students were males and 65, 4 percent belonged to 19-25 years age group. Transient pulpitis affected 50 percent of cases; while dental caries were present in 46.9 percent. 60,4 percent of patients were treated with conservative treatment. Conclusions: among the studied population, the most common pulp´s disease is reversible and transitory pulpitis. The most affected students are males and from 19-25 years age group. Dental caries, followed by poor seals are the most frequent causes of pulp disease. Conservative therapy is the most widely used therapy in these cases(AU)