Millers contribution, along with the research on plaque by G. V. Black and J. L. Williams, served as the foundation for the current explanation of the etiology of caries. Several of the specific strains of lactobacilli were identified in 1921 by Fernando E. Rodríguez Vargas. In 1924 in London, Killian Clarke described a spherical bacterium in chains isolated from carious lesions which he called Streptococcus mutans. Although Clarke proposed that this organism was the cause of caries, the discovery was not followed up. Later, in 1954 in the US, Frank Orland working with hamsters showed that caries was transmissible and caused by acid-producing Streptococcus thus ending the debate whether dental caries were resultant from bacteria. It was not until the late 1960s that it became generally accepted that the Streptococcus isolated from hamster caries was the same as S. mutans.Tooth decay has been present throughout human history, from early hominids millions of years ago, to modern humans. The prevalence of caries increased dramatically in the 19th century, as the Industrial Revolution made certain items, such as refined sugar and flour, readily available. The diet of the "newly industrialized English working class" then became centered on bread, jam, and sweetened tea, greatly increasing both sugar consumption and caries. Etymology and usage
Naturalized from Latin into English (a loanword), caries in its English form originated as a mass noun that means "rottenness", that is, "decay". The word is an uncountable noun. Cariesology or cariology is the study of dental caries.
The teeth most likely affected are the maxillary anterior teeth, but all teeth can be affected. The name for this type of caries comes from the fact that the decay usually is a result of allowing children to fall asleep with sweetened liquids in their bottles or feeding children sweetened liquids multiple times during the day.Another pattern of decay is "rampant caries", which signifies advanced or severe decay on multiple surfaces of many teeth. Rampant caries may be seen in individuals with xerostomia, poor oral hygiene, stimulant use (due to drug-induced dry mouth), and/or large sugar intake. If rampant caries is a result of previous radiation to the head and neck, it may be described as radiation-induced caries. Problems can also be caused by the self-destruction of roots and whole  tooth resorption when new teeth erupt or later from unknown causes. Children at 6–12 months are at increased risk of developing dental caries. For other children aged 12–18 months, dental caries develop on primary teeth and approximately twice yearly for permanent teeth.A range of studies have reported that there is a correlation between caries in primary teeth and caries in permanent teeth. Rate of progression
Temporal descriptions can be applied to caries to indicate the progression rate and previous history. "Acute" signifies a quickly developing condition, whereas "chronic" describes a condition that has taken an extended time to develop, in which thousands of meals and snacks, many causing some acid demineralization that is not remineralized, eventually result in cavities.