“…Over forty years ago it was found that dental extractions produced a transitory bacteraemia and it was suggested that this phenomenon had a bearing on the aetiology of infective endocarditis in patients with rheumatic and congenital heart disease (Okell & Elliott 1935). It is known now that most dental manipulations including extractions (Jones et al 1970), scaling (Bandt et al 1964, Conner et al 1967, surgical periodontal procedures (Korn & Schaffer 1962, Bender et al 1963, filling of teeth (Harvey & Capone 1961) and root canal treatment (Farrington 1973) introduce bacteria into the blood stream as do such patient performed procedures as chewing (Cobe 1954), oral irrigation (Romans & App 1971, Berger et al 1974) and tooth-brushing (Cobe 1954, Rise et al 1969, Sconyers et al 1973, Madsen 1974.…”