Oral microbiota in crevices around dental implants: Profiling of oral biofilm

Large numbers of bacteria (>10⁶/mm²) generally inhabit the surface of the oral cavity, particularly at the interface between teeth and gingiva, as an oral biofilm (microbiota). The establishment of anaerobic bacterial culture and molecular biological techniques has enabled us to isolate and detect various bacterial species from oral biofilm. It has been estimated that more than 600 bacterial species inhabit the oral cavity. Nevertheless, the oral cavity is considered healthy when the oral microbiota is composed of indigenous bacteria. Numerous environmental changes in the oral cavity may lead to accumulation of dental caries-associated or periodontitis-associated bacteria, resulting in the initiation of dental caries or periodontitis, respectively. The environment in crevices around dental implants is considered similar to that in subgingival sulcus, such as neutral pH, anaerobiosis and rich nutrition (e.g., amino acids and peptides). The environment may be supportive of anaerobic growth of the bacteria in microbiota in crevices around implants, particularly at the interface between histocompatible artificial material and mucosal epithelium. The microbiota may trigger inflammation in the tissue around the implants. In this article, the current topics on the profiling of oral microbiota in crevices around implants are reviewed.