The effect of tooth brushing frequency on plaque, gingival indices in Thamar Governorate (primary, intermediate, secondary schools) in Republic of Yemen. MDJ [Internet]. 2004 Jun. 15 [cited 2025 May 12];1(1):113-20. Available from: https://mdj.uomustansiriyah.edu.iq/index.php/mdj/article/view/1101