Tongue coating and salivary bacterial counts in healthy/gingivitis subjects and periodontitis patients

Background: The papillary structure of the dorsum of the tongue forms a unique ecological site that provides a large surface area favoring the accumulation of oral debris and microorganisms. These micro-organisms of the tongue may be of influence on the flora of the entire oral cavity. The normal appearance of the dorsum of the tongue is either pinkish or has a thin white coating. For the present study a scoring method was developed to describe the appearance of the dorsum of the tongue in relation to the extent of color and thickness of tongue coating. Aim: The purpose of this study was to investigate the discoloration and coating of the tongue in healthy/gingivitis subjects and periodontitis patients. Furthermore, to determine the relationship between the appearance of the tongue and the bacterial load in salivary samples. Material and Methods: 2 groups of patients were studied, 70 healthy/gingivitis subjects and 56 periodontitis patients. After scoring of the tongue a salivary sample of each patient was taken and analyzed using a phase-contrast microscope. Results: This investigation showed that most discoloration was found on the distal part of the tongue. The mean number of bacteria per ml sample in relation to a pink, white and yellow appearance of the tongue was 948, 855 and 900 (×106) respectively. The mean number of bacteria per ml sample in relation to no, thin and thick coating was 948, 863, and 895 (×106), respectively. Analysis did not reveal a relationship between discoloration, coating thickness and total bacterial load. The mean number of bacteria per ml in healthy/gingivitis subjects was 860 and in periodontitis patients 918 (×106). Conclusion: No relationship between the appearance of the tongue and salivary bacterial load could be detected. There was no difference in bacterial load between the healthy/gingivitis and the periodontitis group within the present study population.