Investigations into the micro-ecology of oral malodour in man and companion animals.

The loads and locations of bacterial types associated with oral malodour on the tongue surface and gingival crevice were investigated in man and the dog respectively. In the human study, samples were taken from 50 subjects with brushes at the dorsal anterior, dorsal middle, dorsal posterior, dorsal posterior to the circumvallate papillae (DPCP), lateral posterior and ventral posterior (VP) surfaces, and cultured appropriately. Malodour was assessed by trained judges. Mean volatile sulfur compound (VSC) producing bacterial counts (colony forming units/brush × 10(5)) were found to be highest (88.94) and lowest (0.33) at the DPCP and VP sites respectively. Anaerobic, gram-negative and VSC counts at DPCP surfaces increased with malodour intensity, whereas aerobic and S. salivarius counts decreased. The prevalence and populations of the VSC producing Porphyromonas and Prevotella species were determined in the dental plaque from 34 dogs. Porphyromonas gulae and Prevotella intermedia were present in 68% and 44% of dogs, and 47% and 23% of plaque samples respectively. P. gulae and Prev. intermedia counts increased with plaque quantity (P < 0.05) and gingivitis (P < 0.1). The close association observed between canine periodontal disease and measurements of oral malodour is supported.