A comparison of partial and full mouth scoring of plaque and gingivitis in oral hygiene studies

The clinical testing necessary to demonstrate the safety and efficacy of new toothbrushes is complex and expensive. Any modification of methodology that could reduce complexity and cost without compromising quality would benefit both investigators and the public. Results from an 8-week toothbrush study were assessed for the use of partial as compared to full-mouth evaluations. The potential utility of an objective, minimally-invasive bleeding index for the evaluation of gingivitis was also tested. 2 partial evaluations, half-mouth and molar/anteriors, revealed decrements in modified gingival index (MGI), bleeding index and plaque index that were statistically significant and similar in magnitude to those derived from full-mouth examinations. % decrements in MGI and bleeding index based on the Ramfjord teeth were not significant statistically. Results for the new sulcular bleeding index were essentially similar to those for the MGI. However, the bleeding index offered the advantage of improved objectivity for use in both white and non-white subjects. These results suggest that partial evaluations and the new bleeding index may be useful elements in the design of toothbrush efficacy studies.