The effect of different plaque control modalities on the keratinizing potential of the sulcular epithelium in monkeys

The purpose of this study was to determine if various plaque control regimes would be effective in permitting the gingival sulcular epithelium to keratinize. Three adult Rhesus monkeys had their teeth scaled and were placed on specific plaque control regimes including various combinations of prophylaxes, topical chlorhexidine and systemic tetracycline. Over the 2-month experimental period, weekly Plaque and Gingival Indices were determined. Subgingival plaque samples were obtained during the first 2 treatment weeks and at the end of the 1st month. Block sections of individual teeth from the different experimental regimes were serially sectioned to be evaluated histologically for inflammation and keratinization. Plaque and Gingival Indices were significantly reduced by the end of the 8th week compared to the pretreatment levels for all experimental regimes, except that the regime consisting only of three prophylaxes per week failed to reduce the Gingival Index significantly. Rubber cup prophylaxes were less effective in reducing plaque and inflammation than when the prophylaxes were combined with topical chlorhexidine application or systemic tetracycline administration. However, all experimental regimes were capable of reducing the subgingival bacterial flora to a level permitting sufficient reduction in gingival inflammation so that sulcular keratinization would occur. Some degree of sulcular keratinization was observed for every tooth of all experimental regimes. All regimes caused a significant decrease in the Inflammatory Indices relative to the control values. A negative correlation was found between the Crestal Inflammatory Index and the Keratin Width and Keratin Length, while a positive correlation was apparent between the Keratin Width and Keratin Length.