Bone resorptive activity in symptomatic and asymptomatic apical lesions of endodontic origin.

OBJECTIVES: The aim of this study is to assess the levels and diagnostic accuracy of a set of bone resorption biomarkers, including TRAP-5, RANKL, and OPG in symptomatic and asymptomatic apical lesions and controls. MATERIALS AND METHODS: Apical tissues from symptomatic and asymptomatic apical periodontitis patients and periodontal ligaments from healthy teeth extracted for orthodontic reasons were processed for tissue homogenization and the levels of TRAP-5, RANKL, and OPG were determined by multiplex assay. Marker levels were analyzed by Kruskal Wallis test, and diagnostic accuracy was analyzed with ROC curves. RESULTS: Higher levels of RANKL, OPG, and RANKL/OPG ratio were determined in both types of apical lesions compared to healthy periodontal ligament, whereas higher TRAP-5 levels were found only in symptomatic apical lesions (p < 0.05). OPG, RANKL, and RANKL/OPG ratio showed diagnostic potential to identify apical lesions versus healthy controls (AUC = 0.69, p < 0.05); while TRAP-5 showed a potential to discriminate symptomatic versus asymptomatic apical periodontitis (AUC = 0.71, p < 0.05) and healthy controls (AUC = 0.83, p < 0.05). CONCLUSIONS: Apical lesions showed higher RANKL and OPG levels than healthy tissues. TRAP-5 levels were the highest in symptomatic apical lesions, suggesting that these represent a progressive state, and showed diagnostic potential. CLINICAL RELEVANCE: Clinically symptomatic apical periodontitis might represent biologically progressive apical lesions based on TRAP5 levels. TRAP5 has diagnostic potential to identify these lesions, representing a candidate prognostic biomarker.

Asociación entre niveles de TNF-a en fluido crevicular gingival de dientes con periodontitis apical asintomática / Levels of TNF-a increase in gingival crevicular fluid of teeth with asymptomatic apical periodontitis

Introducción: Como consecuencia de necrosis pulpar séptica, el ingreso de productos bacterianos en el periápice induce la producción de citoquinas pro-inflamatorias como el Factor de Necrosis Tumoral (TNF)- a, que entre otras funciones participa en la diferenciación y activación de los osteoclastos para inducir reabsorción ósea, fenómeno característico de la periodontitis apical asintomática (PAA). El fluido crevicular gingival (FCG) ofrece un gran potencial como fuente de factores asociados con la actividad osteoclástica. El objetivo del presente estudio fue determinar los niveles de TNF- a en FCG de dientes con PAA y controles sanos contralaterales. Métodos: Se incluyeron 14 pacientes en la Clínica de Endodoncia de la Facultad de Odontología de la Universidad de Chile con diagnóstico clínico de PAA y se obtuvieron muestras de FCG con tiras de papel a partir de los dientes afectados y sanos contralaterales por un periodo estandarizado de 30 segundos. Se determinaron las concentraciones de proteínas totales mediante el método del ácido bisciconitico y los niveles de TNF- a, mediante ensayo ELISA. Los datos se analizaron con Test-t pareado utilizando el programa StataV11. Resultados: Se detectaron niveles de TNF- a significativamente mayores en el FCG de dientes con PAA estandarizados, tanto por 30 segundos de toma de muestra como por mg de proteínas totales. Conclusiones: Este estudio provee evidencia preliminar de que los niveles de TNF- a en el FCG reflejan la presencia de PAA y podría ser de utilidad como complemento al diagnóstico clínico y monitoreo del estado de salud o enfermedad de los tejidos perirradiculares.

Introduction: As a consequence of septic pulp necrosis, the entry of bacterial products into periapical tissues induces the release of pro-inflammatory cytokines, such as the tumor necrosis factor (TNF)- a. This pleiotropic cytokine is involved in the differentiation and activation of osteoclasts to induce bone resorption, a hallmark of asymptomatic apical periodontitis (AAP). Gingival crevicular fluid (GCF) has a great potential as a source of factors associated with osteoclastic activity. The aim of this study was to determine the levels of TNF- a in GCF of teeth with PAA and contralateral healthy controls. Methods: A total of 14 patients with clinical diagnosis of AAP were enrolled from the Clinic of Endodontics, Faculty of Dentistry, Universidad de Chile during 2009 and 30-second GCF samples were obtained with paper strips from AAP teeth and contralateral healthy controls. Total protein concentration and TNF- a levels were determined through bisciconitic acid method and ELISA assay, respectively. Paired t test and StataV11 software were used for statistical analysis. Results: Levels of TNF- a were significantly higher in GCF from teeth with AAP than controls when standardized by either 30s of sampling and total protein content. Conclusions: The present study provides preliminary data supporting that TNF- a levels in GCF reflect periapical status. Screening of TNF- a levels in GCF might represent a useful side-diagnostic tool to the monitoring of the apical status.