W.D Miller proposed the bacterial model or theory of decay in the 1890's. And that is exactly what it was - a theory. A theory that the dental profession took hold of and ran with ever since. Yet, as early as the 1920's there were those who contested Miller's theory as flawed.
Miller's theory does not explain dental disease in all cases. As I mentioned above there are exceptions:
Teeth do not always decay in the presence of food debris. Some people are immune to cavities even when there is food on their teeth.
There appears to be an increase in susceptibility to dental decay during pregnancy, times of stress and systemic illness. Which implies that there is a systemic component to dental decay.
Dead teeth appear to be more prone to decay than live ones. If decay happens from the outside, then root filled teeth would be as susceptible to tooth decay as teeth without root canal fillings. Thus teeth without pulp (the nerve and blood supply) should decay at an equal rate as teeth with pulp but dead teeth decay more readily. Could this suggest that something is missing in the nutrient supply to the tooth.
Decay that starts between the teeth often affects only one of the two adjacent teeth. Bacteria don't strike evenly, implying a systemic condition that causes cavities.
Mottled poorly calcified enamel, is not more susceptible to decay than normal enamel.
Because these exceptions occur, it suggests something is missing from the sugar-bacteria theory given by Miller. Dentistry must consider more than sugar and bacteria when it comes to tooth decay and really look at the predisposing factors that lead to tooth decay and how decay relates to the structure of the tooth and the processes that remineralise and nourish it.
Decay and Dentinal Fluid Theory
When tooth enamel was first studied it was found that enamel is made up of an organic matrix that receives nutrients from inside of the tooth from a fluid that flows from the pulp through the tooth out into the mouth. The fluid is called dentinal fluid or dental lymph.
Consider what happens when you sweat - fluid from inside your body passes through your skin to the outside. In a way the flow of dental lymph is like your tooth being able to perspire.
The quality of flow and transportation of nutrients and minerals through the tooth gives the tooth resistance to dental decay. A tooth is a living structure, it needs nutrients supplied on a daily basis just like any other tissue in the body in order to maintain good, decay -free health and for this the tooth relies on the dentinal fluid to keep it strong and healthy.
This proposal as to why teeth decay put forward by Drs. Ralph Steinman and John Leonora is known as the Dentinal Fluid Theory or DFT.
The research clearly demonstrated a flow of body fluids through teeth from the inside to the outside even through the enamel. So long as the direction and pressure of this fluid flow was maintained there was no decay. Reduction in the fluid pressure lead to an increase in decay no matter how much tooth brushing went on. The critical part of this research is that the flow of fluid through the tooth is dependant on diet and stress levels.
The DFT research also discovered a hormone called ‘parotid hormone’ which is made in the major salivary glands in the cheeks called the parotid gland. Parotid hormone regulates dentinal flow. Production of this hormone is dependant on a proper diet and gets inhibited by sugar and refined carbohydrates.
There are certain foods that are universally decay producing. Sweets and soft drinks are the main offenders due to the sugar interfering with your endocrine (hormone) system.
So it would appear there is more to tooth decay than simply improper brushing and flossing and sugar consumption.
Dental decay is a symptom of systemic disease and imbalances.
Often bacteria are present when tooth decay is active, but they are not the sole cause of it.
In order to prevent cavities it is essential to consider all theories behind tooth decay and from there take a holistic approach to prevention by focusing on diet, toxicity, inflammation and lifestyle choices.