 Hello everyone, welcome back to another session in Dentistry and Work. Today's topic in Paradontics is Socoransky criteria for Paranodal Pathogen. So when a baby born, the baby's oral cavity is completely devoid of microorganisms. Not a single bacteria is present in baby's oral cavity. From where does the bacteria is coming from? So the baby gets these bacterias from the baby's mother, caregivers or any person who gets contact with the baby. So that's how it all starts. So all of us will be having many types of bacterias in our oral cavity. Not all bacterias are pathogenic, some are pathogenic, some are not very pathogenic. So the pathogenic bacteria also not present in the same amount in all person, all person's oral cavity. It may vary from person to person, depends upon the person's oral hygiene, its habits, its body health, the systemic diseases. And many factors are involved in depending upon the amount of bacteria, that is pathogenic bacteria. If a person is having a periodontal disease, the periodontal pathogen will be very high in his oral cavity compared to a healthy person. So the many types of bacteria is present such as Fusibacterium, Porphyromonase, Pryvortyla, Tryponema, the Plasmodium group, Tryponema, Denticola, many types of spirochetes and all these are various types of periodontal pathogen. So moving on to Sokran's criteria, if a group of bacteria or a group of microorganism is to be named as pathogen, it should follow these five principles. We have heard this principle before but not the Sokran's criteria. We have heard the famous coach postulates regarding the bacteria in the last of 19th century coach postulates. So it was rejected anyway but this is similar to coach postulates but in a different way. So what are the criteria for a group of bacteria to be named as pathogen, especially periodontal pathogen? The Sokran's criteria, the first one is these group of bacteria or microorganisms must be associated with a disease and there should be increase in number of organism at diseased sites. So if a particular tooth is having localized periodontitis, then we should have more number of that particular microorganism. The Porphyromonase, Dinjevalis or Actinomycetamcomitants, so compared to the other sites or compared to a healthy site. So that is the first criteria, there will be increased number at the diseased site. If that is happening, we can say that that group is a periodontal pathogen. And the second one is it should be eliminated or decreased in sites that demonstrate clinical resolution of disease with treatment. If we are doing a treatment to control the disease, it should be eliminated or reduced in number. If it is getting eliminated or if the count is getting reduced after a treatment, we can say that that particular group is a periodontal pathogen. Because it is subjected to the treatment modalities that decrease in number by the effect of treatment. The third one is it should be demonstrate a host response in the form of an alteration in the host, cellular or the humeral immune response. So you know when an antigen enters a body, what happens? The body's immune system tries to attack against it. The body tries to protect ourselves by making an immune response. So if a pathogen, if a bacteria, a group of microorganisms can create a host response, we can say that it is a pathogen. Especially in case of this one, it is a periodontal pathogen. And the fourth one is it must be capable of causing disease in experimental animal model. So all the things, if we can recreate in a sterile animal or an experimental animal model, we can say that it is a periodontal pathogen. So if we can prove the same disease, if we can create the same disease in a healthy experimental animal model, it could be a rat, it could be a rabbit or anything, we can say that it is a periodontal pathogen. And the last one is it must demonstrate the virulence factor responsible for enabling the microorganism to cause the destruction of periodontal disease. And the fifth one is it must demonstrate the virulence factor responsible for enabling these microorganisms to cause destruction of periodontal tissues. Virulence factors are nothing but molecules which helps these bacteria to get colonized and cause the destruction of periodontal tissues. So it should demonstrate virulence factor, then we can call it as a periodontal pathogen. So these are the five criteria Socrates' key put forward to name any group of bacteria or microorganisms as a periodontal pathogen. One is the increased number at diseased sites should be eliminated after treatment. It must demonstrate a host response and it must cause disease in experimental animal and it must demonstrate virulence factor. That's all for now. I hope you understood the very small concept just like the course postlates how a bacteria or a group of microorganism is to be named as periodontal pathogen. So I'll come up with a new topic in periodontics. Thank you. And lastly guys, we have started channel membership in the industry 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. You will get answered through WhatsApp text messages or voice messages. And we have one more option that is the PDF notes will be available. But as of now we have only the public health industry topic. The more topics will be uploaded soon. And the last option is one to one interaction session. 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