EFFECT OF PREEXPERIMENTAL MAINTENANCE CARE DURATION ON THE DEVELOPMENT OF GINGIVITIS IN A PARTIAL MOUTH EXPERIMENTAL GINGIVITIS MODEL

The present study was designed to evaluate if different periods of sup ervised oral hygiene prior to the experimental gingivitis trial have a n effect on the amount of inflammation which develops in the 'toothshi eld' model. Two groups were compared. One group (Group A) was supervis ed over a 5-month period before experimental gingivitis. Six months la ter Group A participated in a second trial, this time receiving only a 1-month pretrial. A second group (Group B) which served as a control was supervised over a pre-trial period of 1-month prior to the start o f the experimental gingivitis phase. During the pre-trial period all s ubjects undertook a regime of vigorous oral hygiene which included pol ishing of the test quadrant in the upper jaw and supervised subgingiva l brushing, interdental taping or the use of toothpicks. The presence of plaque and bleeding were assessed. Following the pre-trial period a ll plaque control measures in the experimental area were prevented dur ing oral hygiene periods by the temporary placement of soft, loosely f itting vinyl toothshield guard. During this period they accumulated pl aque rapidly and developed a generalized gingivitis. The results of th is study indicate that, irrespective of the length of the pretrial per iod, subjects by group develop a comparable mean level of plaque and g ingival bleeding. However, the extent to which gingivitis develops dif fers among individuals and was for a number of subjects not consistent . Therefore, in designing an experimental gingivitis trial care should be taken to include a sufficient number of subjects to account for in dividual variation.