“…16,17 In dental practice, factors contributing to denture failure include unbalanced occlusal force, smoking, bone condition, improper handling, and mistakes in denture fitting, including injury, inadequate denture design, nonobservance of oral hygiene rules, presence of concomitant diseases, in particular, diabetes mellitus, and others. 16,[18][19][20] Bacterial infection is considered to be the most important factor contributing to denture failure, and the microbiota includes Prevotella intermedia, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Bacterioides for sythus, Treponema denticola, Prevotella nigrescens, Pepto streptococcus micros, Fusobacterium nucleatum, and several other microorganisms causing peri-implantitis. 12,14,21,22 Bacteria are a key etiological factor in periodontal disease, so the composition of the microbiota in the areas surrounding the denture may have a significant impact on the condition of this area in the following.…”