The cariogenicity of a substance depends on many factors like pH, sucrose concentration, physical properties of the substance, time etc. Out of these factors, which is the most important factor that determines the cariogenicity of a substance?
Ralph Steinman, DDS was a cariologist I studied under in dental school. He discovered Parotid Hormone. He did a study involving removing the Parotid glands from rats and gave the test group a high sugar diet supplemented with Parotid Hormone. The test rats did not develop the caries of the control group. The acid producing bacteria, of course, metabolize the sugars and excrete acids which can dissolve the susceptible substance or tooth. Fluoride will neutralize the acids. It seems to me that any of the triad participants in the decay process could be the major factor if one is to the extreme. I once had a patient who kept her teeth very clean but had acidic erosion of her teeth because she dissolved a stomach acid pill in her mouth as she did not like swallowing pills.
Others have been following up on Dr. Steinman's work. Ken Southward in Canada wrote on his systemic theory in the Academy of General Dentistry in 2011. Here is a link to one of his earlier papers: www.dentaltown.com/Images/dentaltown/magimages/0906/DTSep06pg12.pdf
This is the NCIB link to his AGD paper abstract: : www.ncbi.nlm.nih.gov/pubmed/22313822
There certainly seems to be more to think about regarding decay. I know we all wish we had the complete answer. Hope this helps.
In the answers above there is a strange mix of cariogenic and erosive potential. Tooth erosion is the direct effect of a low-pH substance on teeth. The low pH of the consumed food will cause direct dissolution of the tooth. This has nothing to do with Caries. Caries is a much slower process caused by the metabolization of sugars by oral bacteria. Bactera produce acids when they metabolize sugars. It is generally accepted that after the consumption of sugar containing foods, the pH of the plaque will be reduced for some time (stephan-curve) and then will come back to more neutral values. There is no clear answer if the sucrose concentration in the food has a direct link to the cariogenicity of the food. If the sugar concentration in the food is reduced by half, the cariogenic challenge might still be high. The pH in dental plaque will drop rapidly and at reduced pH values most organisms do not consume sugar anymore and will not produce additional acids. So, if the sugar content is higher, part of the sugars will not be consumed. To my opinion caries risk is more related to the number of sugar exposures (eating/snack frequency) than to the sugar concentration in the food.
caries is bacterial origin disease, caries initiation mainly depend on sucrose depending bacteria, however, caries progression.may be affected more by reduced pH which offers suitable media for nonsucrose dependent bacteria
The cariogenicity of a substance depends on several factors, for example today the association between sucrose and the caries experience no longer has such a strong association due to the presence of fluorides, so the data of a strong association were established in the era before fluorides. See (Burt BA, Pai S. Sugar consumption and caries risk: a systematic review, J Dent Educ. 2001; 65: 1017-1023).
I am agree with Rob Exterkate clearly expressed, cariogenicity on some particular food, depends not only on it´s sucrose concentration or pH. We must consider oral bacteria on the caries process, virulence of microorganisms and CFU. Phisycal properties of a food have a direct relation on it´s solubility, adhesive properties ( sticky foods) . Salivary flow , as a protective factor, has an important rol in pH recovery and clearance time in the oral cavity.