Gram‐positive organisms in endodontic infections

Culture‐based studies in endodontics have more or less overlooked the significance of Gram‐positive facultative bacteria in recent decades. By contrast, Gram‐negative anaerobes have been extensively studied because of their frequent recovery in primary root canal infections and their association with acute manifestations of apical periodontitis. More recent years have seen a renewed interest in Gram‐positive facultatives as these organisms are common in samples from root‐filled teeth affected by apical periodontitis. Structural components of the robust bacterial cell wall of Gram positives protect them from noxious environmental factors. Additionally, the majority of these organisms express fast‐adaptive properties when exposed to extreme conditions, thus making them potentially interesting as causal elements in post‐treatment endodontic disease. This review relates to different aspects of Gram‐positive bacteria and their adaptive responses when being exposed to stressful conditions such as endodontic treatment procedures.