Histologic evaluation of the effects of intrasulcular toothbrushing on human sulcular epithelium

Nineteen young adult Caucasian males had an average Gingival Index Score of 0.47. Each was asked to demonstrate his present method of toothbrushing: thirteen used the scrub method, and six combined the scrub and roll methods. Control gingival tissue specimens were taken from the mandibular left first bicuspid or first molar regions, and the area was allowed to heal for 40 days. Following complete healing, intrasulcular brushing was used in the mandibular left posterior segment, for 30 seconds daily for a period of 40 days. The brushing was done by the investigator on 28 days and by the subjects on 12 days. The average Gingival Index Score following intrasulcular brushing was 0.25. A gingival specimen was taken from the experimental area of the mandibular left second bicuspid region. Histological findings in control specimens from 13 subjects showed parakeratinization for varying distances in the sulcus epithelium apical to the gingival crest. In six specimens a complete absence of sulcus keratinization was observed. The average Inflammatory Index Score was 1.21. Following intrasculcular brushing, 18 specimens showed a parakeratin layer apical to the gingival crest; in 14, it extended the entire length of the coronal sulcular epithelium or apparent clinical sulcus, whereas in four more it extended well beyond the gingival crest into the sulcus. In the six subjects whose control specimens showed an absence of keratin apical to the gingival crest, parakeratinization of part or all of the clinical sulcus was found following intrasulcular brushing. The average Inflammatory Index Score was 1.015. A moderately intense acute inflammatory reaction was observed within the attachment epithelium in three subjects. Possible therapeutic benefits and hazards of intrasulcular brushing are discussed.