[Gingival response by the effect of brushing method and hardness of the toothbrush bristle]

The effect of toothbrushing is plaque removal and gingival massage. However, intensive oral hygiene frequently results in gingival damage. The object of this study was to determine the damage to oral soft tissues resulting from three methods of brushing (roll, scrub, and bass method) and the use of toothbrushing with two different hardness (Hard: 10.2 kg/head, Soft: 3.2 kg/head). Six monkeys were used for this study. The mouth of each was divided into four sections: upper right for a control, upper left for the scrub method, lower right for the roll method, and lower left for the bass method. The roll method was run at 10 strokes per 10 seconds with a load of 800 grams, and the scrub and bass methods were run at 30 back and forth strokes per 10 seconds, with a load of 400 grams for each method. During the experimental period of five months, brushing by each of the three methods were done once a day. The gingival index, the gingival bleeding index, pocket depth, width of attached gingiva, and gingival recession were measured regularly. Analysis was performed by analysis of variance (ANOVA). The scrub method resulted in greater gingival recession and, at the same time, loss of attached gingiva than the roll and bass methods. The use of the hard brush resulted in greater gingival recession and loss of attached gingiva than the use of the soft brush. With the three methods of brushing, a significantly greater distance of gingival recession and loss of attached gingiva were recorded after brushing by the scrub method than by the roll and bass methods. The study also showed that the modest gingival recession and reduction width of attached gingiva seen with the scrub method and increased stiffness of toothbrush bristles were accompanied by increased damage to the soft gingival tissues.