In the absence of disease, the cre- vicular mucosa serves as a barrier to bacterial invasion. As in adults, however, the child s gingival crevice is most likely the source of virtually all transient bacteremia that occur from the mouth, whether from office-based dental procedures or routine activities of daily living such as toothbrushing. Gingival inflam- mation, however, may lead to thinning and ulceration, allowing dense colonies of bacteria and bacterial byproducts ready access to the increased gingival capillary circulation. Bacteremia may then result from minimal gingival manipulation. Children have a much lower prevalence and severity of gingivitis and periodon- titis than adults, and data from bacteremia studies in adults may not be representative of children. Bacteremia From Dental Procedures Dental procedures are a frequent source of bacteremia, par- ticularly from VGS.40 48 Multiple clinical studies of chil- dren over the past 40 years focused on the impact of 1 of the following risks for development of bacteremia: class of prophylactic antibiotic drug49 ; nature and invasiveness of ; indices of oral hygiene and dis- ; timing of blood culture draws before, dur- ing, and after the dental procedure45,48,56 ; various methods of microbial analysis and identification44,57 ; and the impact of these variables on surrogate measures of risk for IE, such as the incidence, duration, nature, and magnitude of bactere- Clearly, these surrogate measures are also influenced by multiple host factors. 