Acquisition of mutans streptococci and caries prevalence in pediatric sickle cell anemia patients receiving long-term antibiotic therapy.

PURPOSE The purpose of this study was to: (1) evaluate the prevalence of mutans streptococci (MS) and dental caries in sickle cell anemia (SCA) patients receiving long-term prophylactic penicillin therapy; and (2) determine changes in MS colonization and dental caries upon discontinuing the antibiotic. METHODS Sixty subjects with SCA and 60 age- and race-matched control subjects participated in this study. The SCA subjects were divided into 2 separate age groups: (1) group 1 subjects were under 6 years of age and received penicillin twice a day; and (2) group 2 subjects were 6 to 12 years old and received no daily prophylactic antibiotics, although up to age 6 they had received daily penicillin before it was discontinued. DMFS/dmfs scores for all subjects were obtained through a comprehensive dental examination including bitewing radiographs. Stimulated salivary samples to assess MS levels were obtained on all subjects. Data on medical, dental, fluoride, and dietary history were obtained on all patients through a written parental questionnaire. RESULTS No group 1 patients had positive cultures for MS. In contrast, 70% of marched controls cultured positively for MS (P<.01). The DMFS/dmfs score for group 1 was 0.21 vs 5.1 for the control group (P<.01). Differences in surfaces affected were also noted, with no group 1 patients having interproximal lesions compared to 47% of control subjects having these lesions (P<.01). Group 2 also had significantly lower levels of MS than matched controls (47% vs 97%, P<.01), although there was no statistically significant difference in caries prevalence or surfaces involved. CONCLUSIONS These findings demonstrate that long-term penicillin prophylaxis in SCA patients likely prevents the acquisition of MS, resulting in significantly lower caries rates in these patients. This benefit occurs only during active administration of the drug, however, and only delays the acquisition of MS.