The relevance of pH to gingivitis and periodontitis.

Although the resting pH of the oral cavity is between 5 and 9, it is also known to vary widely depending on a number of factors. While this phenomenon has been extensively studied in relation to dental caries, little research has been undertaken of its possible significance in relation to gingivitis and periodontitis. This study aimed to investigate any possible correlations between pH and gingivitis and periodontal pocketing. Forty-two subjects with gingivitis and periodontitis were included in this study. Strips of pH indicator paper were placed on the floor of the mouth, soft palate, healthy gingival margins, sites of superficial gingivitis, and in periodontal pockets. It was shown that pH varies in different sites in the mouth. Statistically significant correlations between pH and gingivitis were not identified, but significant correlations between pH and periodontal pocketing were evident, although wide variations were observed between pockets. Randomly distributed pH readings ranging from 2-9 were observed within a single periodontal pocket. This implies that the physiology of processes taking place within periodontal pockets is wide ranging and complex. Different levels of pH indicate different chemical environments which may imply that different disease and reparative processes are occurring simultaneously within each periodontal pocket. The limitations of the assessment technique used in this study were highlighted and compared in relation to results obtained from other studies using more sophisticated techniques and it was found that the results obtained using this unsophisticated technique were in agreement with most of these other studies. Therefore, this technique may have applications in screening for disease activity in clinical practice. However, the need for further work to confirm the observations of this study is necessary to corroborate these associations.