Oral hygiene and periodontitis ( Color Atlas of Dental Medicine : Periodontology 2nd edition 1989 P.160 ) As meaningful as oral hygiene is for disease prevention, gingivitis treatment, and oral health maintenance, it is relatively ineffective, when used alone, for treatment of periodontitis. Even for a highly motivated and dextrous patient, there exist clear limitations: The best efforts in home care cannot reach the deep subgingival plaque. Concrements and endotoxin-containing cementum can never be removed by the patient. Moderate to severe periodontitis thus can scarcely by influenced by oral hygiene. Cercek et al. (1983) demonstrated this in a human clinical study: Patients with periodontitis were treated in three phases: A. In an initial 5-month phase, patients were instructed and motivated in the use of the toothbrush and dental floss. No professional tooth cleaning was performed. B. In a second, 3-month phase, the same patients were provide with instruction for use of the Perio-Aid, in addition to their previous oral hygiene. Patients used the rounded toothpick to clean the marginal areas as deeply as possible subgingivally. C. Following these two hygiene phases, a professional scaling (Cavitron) was performed supra- and subgingivally using local anesthesia. Patients were than examined for 9 months. The results of this study clearly demonstrated that the oral hygiene efforts of the patients alone ( first and second phases ) were effective in dramatically reducing the Plaque Index ( Supragingival plaque ) as well as the Gingival Bleeding Index. On the other hand, probing depth did not significantly decrease. Deeper pockets of severe and more millimeters experienced scarcely 1 mm reduction. This small reduction in pr probing depth was probably due to tissue shrinkage. The level of attachment did not change during the first two phases. Only in the third phase, following professional supra- and subgingival scaling did a significant reduction of probing depths and actual attachment gain occur, especially in deeper pockets. These results demonstrate that oral hygiene alone cannot positively influence periodontitis. Oral hygiene following periodontal treatment Home care is, however, one of the most important factors for maintenance of the results of successful periodontal therapy. Only with optimum plaque control by the patient, enhanced by the dentist or dental hygienist at recall appointments, can recurrence of disease be prevented ( Rosling et al. 1976b, Nyman et al. 1977, Knowles et al. 1979 )