Community Dent Oral Epidemiol. 1995 Oct; 23(5): 319-20.

Periodontal condition and comparison of toothcleaning using chewing sponge, chewing sticks and toothbrushes in 14-year-old schoolchildren in Ghana.

Clerehugh V, Laryea U, Worthington HV.

Department of Periodontology, Leeds Dental Institute, England.