IDENTIFICATION OF INTRARADICULAR BIOFILMS: CLINICAL SIGNS AND DIAGNOSTIC METHODS

Abstract

The success of endodontic therapy is intrinsically linked to the effective elimination of bacterial biofilms, the main etiological agents of apical periodontitis. Due to their self-produced extracellular matrix, these complex communities are highly resistant to host defense mechanisms and antimicrobial agents, persisting in areas of difficult anatomical access (isthmuses, ramifications, and dentinal tubules), which is the primary cause of treatment failures. The clinical identification and accurate diagnosis of these biofilms represent one of the greatest challenges in contemporary endodontics. This research is a narrative literature review designed to synthesize the most recent scientific evidence regarding the identification, clinical signs, and diagnostic methods of intraradicular biofilms. The results indicate the complexity of microbial dynamics, highlighting Enterococcus faecalis due to its strong association with persistent infections. Indirect clinical signs, such as persistent pain and fistulas, suggest an unresolved microbial load. The diagnosis is further enhanced with Cone Beam Computed Tomography (CBCT) to identify anatomical variations and bacterial reservoirs, and in research, Confocal Laser Scanning Microscopy (CLSM) is used to visualize the effectiveness of removal. The discussion reinforces the gap between clinical diagnosis and microscopic reality, indicating that efficient biofilm removal in isthmuses requires irrigant activation techniques, such as passive ultrasonic irrigation or sonic activation (EDDY). It is concluded that the diagnosis should be deepened in understanding bacterial occupation to optimize chemical disinfection protocols and that the inability to eradicate E. faecalis is the main impediment to periapical healing.