 Hello, everyone. Welcome back to another session in dentistry and more. Today's topic is theories of tendril caries. We are very familiar with the concept of tendril caries that is how the tendril caries starts when there is presence of sucrose and bacteria in oral cavity, there will be production of lactic acid which will result in demonization and ultimately the cavitation which is known as tendril caries. This session is about the theories of tendril caries, what were the theories, the old theories and the new theories and how it was explaining about this concept. So, let us see the details of theories of tendril caries. Dental caries are the resist of civilization. So, there were many theories which we are trying to explain the concept behind this. So, we can classify all the theories as the old theories and new theories. The most accepted one is the acidogenic theory by Miller. So, anyway old theories we have exogenous and endogenous theory. Exogenous are things which is coming from outside that is worm theory, chemical theory and parasitic or septic theory. Endogenous particles which is present within the body, humeral theory and vital theory and the new theories are acidogenic proteolytic theory and proteolysis chelation theory. So, we will start with old theory that is a legend of worm. So, it was during the 5000 BC period, it was believed that the tendril caries was caused by worms. These worm and they drank blood of teeth and they fed on roots of joes. So, that was the worm theory. There was no scientific proof. It was completely unscientific and the second theory is the chemical theory. It was put forward in 1890 by Palm Lee. So, it was highlighting the current concept that is a chemical, but he was not able to explain in detail. He said that there was an unidentified chemical agent which is responsible for caries. So, he stated that caries began on enamel surface where food become putrefied. Then it acquires sufficient dissolving power to produce disease chemically. Still he could not explain the actual concept. The next theory was parasitic or septic theory in 1843. This was given by Palm Lee. This is given by Edel in 1843. This was in 1819. So, parasitic theory, he explained that there is a presence of filamentous parasite in plague. He termed it as denticolate and this denticolate is responsible for dental caries. So, that was a parasitic theory. Now, let us move on to the endogenous theory. The first one is humeral theory. So, this theory explains about the four humors of body. So, the four humors of body which are blood, flame, black bile and yellow bile. These are the four humors of the body. So, any change in, so black bile and yellow bile. So, any change in relative proportion of these elements would result in disease. That means dental caries. That is a humeral theory. Whereas, the second one vital theory. So, it came in 18th century. So, this vital theory explains the tooth decay originated like bone gangrene. So, how the bone gangrene caused in the similar way that dental caries also happening. That is a from within the tooth itself. So, from within the tooth itself just like a bone gangrene dental caries happens. That is a vital theory. So, we learned about the old theories exogenous and endogenous. The exogenous were legend of worm, chemical theory, parasitic or septic theory, then the humeral theory and vital theory. Now, let us move on to the new theories of dental caries. And the first one was the acidogenic or chemical parasitic theory. So, this is also known as chemical parasitic theory which is the most commonly accepted theory put forward by W. D. Miller in 1890. So, he was able to explain the concept that is sucrose and bacteria producing lactic acid which causes deminolization and cavitation leads to the dental caries. So, he explained it in a two stage that is it is a chemical parasitic process. The first one there will be decalcification of enamel and which results in total destruction and followed by dissolution of the softened residue. So, there will be involvement of the chemical action and parasitic action. Parasitic action is nothing but bacteria, chemical is the formation of lactic acid. So, he was highlighting the roles of all the four factors like the role of carbohydrate, the role of microorganism and the role of acid and the role of dental plague. But at that time this tetrad concept was not there. This is actually tetrad given by Neubrand, Neubrand's tetrad theory because the tetrad is highlighting the importance of time. But it was came into action very lately but till that time it was just the three factors that is host factor, tooth, the agent factor, bacteria and the diet that is the sugar. So, these three factors combined to form caries. So, similarly Miller was also highlighting the role of carbohydrate, microorganisms, acids and dental plague because all these bacteria are present on the dental plague. So, only if the presence of dental plague will result in dental caries. If we properly clean our teeth, there is no dental plague, there is no dental bacteria which can cause dental caries that is stuctococcus mutants. There has to be presence of bacteria and also sucrose. Without bacteria there will not be caries. So, it is a multi factorial disease all has to be there. So, the second one is the role of carbohydrate. Carbohydrate such as the sucrose mainly. Sucrose is also known as arch criminal, the highly acid producing sugar, arch criminal sucrose. So, the role of sucrose was also highlighted by Miller. And next we have the theory that is proteolytic theory. Proteolytic theory means the organic components that is a protein part of tooth will be destroyed as the initial process. Then the actual remanolization or the inorganic substance dissolution happens. So, proteolytic theory is concentrating the organic portion. But the actual concept is the inorganic or chemical portion. The enamel has 96% of calcified structure that is the inorganic content. So, this is concentrating on organic. Then after that there will be demanolization of inorganic compound. So, we propose that enamel, lamellae or rod sheath that is proteins may be laced which means proteolysis as first event in further progression of bacterial inversion and demanolization. So, that was the concept of proteolytic theory. And the last one proteolysis chelation theory. So, there will be a process of chelation. Chelation is nothing but removal of calcium by forming soluble chelates. So, oral bacteria attack organic component of enamel which is known as proteolysis. Then breakdown products have chelating ability and which dissolves the tooth mineral. So, chelation theory is nothing but the bacteria attack on the protein component. Then this component will cause chelation by dissolving the tooth mineral and resulting in dental caries. So, that is all about theories of dental caries. We have learned in detail about the old theories and the newer theories. We have almost 3, 5, 8 theories. Exogenous, endogenous theory and newer theory can study in this way, the legend of worm, chemical, parasitic, humeral, vital theory, acidogenic, proteolytic theory, proteolysis chelation theory. So, hope you understood the concept of theories of dental caries. I will come up with a new topic in dentistry and more. Thank you. And lastly guys, we have started channel membership in dentistry and more channel. So, you can explore various exclusives for the channel members. So, you can explore various options by clicking on the join button adjacent to subscribe button. So, we have options of personal whatsapp help. So, you can ask any doubts. 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