>the low level hard science

The science is pretty basic. CaCO3 powder made into a paste form provides a source of calcium and alkalinity - protecting the teeth from acid created by bacteria. The rest is marketing. The effective way to deliver flouride is a higher concentration that only touches your teeth, which is how it is used at the dentist after a cleaning.

If toothpaste's success was based on utility there would be brands offering probiotic paste that colonizes your mouth and uses glucose with out making biofilms or having acid as an end product of metabolism. Then you wouldn't even really need to constantly brush your teeth or buy more toothpaste. The maximum utility product would cost a lot to develop and ruin the business model.