title: Decreasing prevalence of salivary lactobacilli in Swedish schoolchildren 1987-1998.
abstract: The prevalence and number of salivary lactobacilli was determined in all schoolchildren starting the 7th grade (12-13 yr; n = 1,578) in comprehensive school located in Kumla, Sweden between 1987 and 1998. Whole saliva samples were collected and transferred to dip-slides (Dentocult-LB) and incubated in room temperature for 7 d. Caries data were collected from the dental records and from bitewing radiographs. Both the number of lactobacilli and the prevalence of manifest caries and restorations exhibited a decreasing tendency and were significantly lower in 1998 than in 1987. The mean caries prevalence (DFS) declined from 5.2 to 1.8. In 1987, 45% of the children harboured high or very high lactobacilli counts ( > or =10(5) CFU/ml) in their saliva compared to approximately 10-15% at the later examinations. The proportion of children with no detectable counts varied between 4-29% during the study period, while children with low counts (10(3)-10(4) CFU/ml saliva) constituted a clear majority at the recent samplings. With such low levels in the population, the use of lactobacilli counts as a didactic tool in dietary counselling must be called into question.
authors.affiliation: Public Dental Clinic, Kumla, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Nylander
authors.forename: I
authors.initials: I
authors.lastname: Kumlin
authors.forename: M
authors.initials: M
authors.lastname: Martinsson
authors.forename: S
authors.initials: S
authors.lastname: Twetman
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D002648:Child; D015169:Colony Count, Microbial; D003376:Counseling; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D004032:Diet; D006801:Humans; D007778:Lactobacillus / Q000302:isolation & purification*; D015995:Prevalence; D011313:Preventive Dentistry / Q000379:methods; D012463:Saliva / Q000382:microbiology*; D013548:Sweden / Q000453:epidemiology