This study aimed to validate or invalidate non-inferiority in the plaque removal efficacy of old versus new toothbrushes in the hands of 7-9 year old children. This study was conducted in 93 Iranian students aged between 7-9 year old.

At baselines, each student is given a new toothbrush which they will use for 3 months. The amount of wearing the 3-month-old brushes will determine by measurement of brushing surface areas using NIH imaging software. The outcomes will be measured after 3 month. The tooth brush which used in this study is "Jordan" with the following specifications: Length: 128 mm, 9 rows of bristles, 27 tufts, 24 monofilaments per tuft, height of monofilaments 10 mm and diameter of filaments 0.3 mm. The students will attend on two occasions following 48 hour periods of no oral hygiene. Following plaque scoring, students will brush with a new tooth brush at one visit and with a brush that they had used previously for 3 months at the other visit. Brushing time was 60 seconds. Plaque then will be re-scored and the percentage reduction in plaque score will be calculate using the Turesky plaque index. All plaque scoring will be performed by one examiner who is blind with the groups allocations.

Inclusion Criteria:

1. subjects should be have central and lateral incisors, first permanent molar in each quadrant of maxilla and mandible
2. they should be without restoration on facial, lingual surfaces
3. subjects should be healthy without any disabilities

Exclusion Criteria:

1. subjects who wearing oral prosthesis,orthodontic brackets or removable appliances
2. subjects using mouthwashes which improve the oral hygiene