 Hello everyone, welcome back to another session in dentistry and more. Today's topic in conservative dentistry is tooth resorption. It is a process by which all or part of a tooth structure is lost due to activation of the body's innate capacity to remove the mineralized tissue, which is mediated by cells such as osteoclast or odendoclast. So a part of tooth is lost, okay, so this is a tooth and a part of a tooth root or crown. So any part it can be, so lost due to the action of odendoclast or osteoclast. So this will be related to bone. So it can be two types, one is physiological and next one is pathological. So physiological tooth resorption, all of us know very well that is the tooth eruption. So the deciduous teeth will be resolved once the permanent tooth. So you know this is deciduous tooth and its root. So once the permanent tooth is getting erupted, so this root will be automatically resolved and this will be exfoliated. So this will come to this position that is physiological resorption. Whereas a resorption which is happening within the permanent tooth that is pathological. So what are the causes of tooth resorption? The one is very apical infection that is a periodontitis, apical periodontitis is the most cause of tooth resorption but the effect is usually slight. Next could be the impacted teeth. This results into pressing on the root of adjacent tooth because we know if there is an impacted tooth, we have a tooth here. So this will create pressure here and there will be resorption. Next is the neoplasm. It usually slow growing tumors like amyloblastoma, giant cell tumors which results into resorption of the related teeth and surrounding bone. Then mechanical stimulation, for example, excessive force in orthodontic treatment due to pressure, chemical irritants like 30% hydrogen peroxide which can result into tooth resorption and also idiopathic resorption which the cause is basically unknown. So another classification is internal resorption and external resorption. So this we can say internal resorption which is happening within the tooth, external which is coming from outside the tooth. So the site of tooth where resorption occurs, there it is within the tooth that is internal. So it is mostly starts with the problem with the pulp and external resorption takes place on the surface of the root near epics. That is mainly due to the problem of periapical issues or this one, the impacted tooth which is coming from outside. Okay, so that is external tooth resorption. So in internal tooth resorption where the dentine and pulp walls begin to resolve centrally within the root canal. So this is the root canal. We have a root canal here, so pulp, root canal, so it's a pulp chamber, okay, so root canal. So the dentine and pulp walls begin to resolve centrally within the root canal. So this can be idiopathic but it is usually secondary to pulpitis. So mostly the pulpal infection which ultimately leads to the internal resorption. So internal resorption will result in a peculiar appearance because this tends to be localized and usually affects the incisors teeth and around pink area appears where the vascular pulp has become visible through the attenuated heart tissue. So which is known as pink tooth of mammary. This is the peculiar appearance is known as pink. So this is because the vascular pulp has become visible through the heart tissue, okay, it is usually asymptomatic, may be detected by chance on routine radiographs. So radiographic appearance of internal resorption, the canal shows enlarged area, margins of deletions are sharp, smooth and clearly defined. So the resorption will have a very clear border, okay, so very clear border, sharp border and walls of the root canal's system balloon out. So it can begin with the clinical crown area that is typically enlarged and varies in size and location, okay, so this is a clinical crown. So clinically the presence of a pink spot in the coronal dentin is due to the presence of granulation tissue just under the enamel. So a pulp test is likely to be positive because the pulp remains partially vital because only one part of the pulp has become resolved, the other part is still vital. So pulp test will definitely give a positive result. So next one is external resorption. So external resorption refers to an attack on the root's external edges, slowly dissolving and weakening of the tooth base and eventually the tooth will also weaken and resorption will happen. So external root resorption can be localized or generalized with a major cause being impaction, okay, so this is as I mentioned, it's major cause and sometimes the cause will be idiopathic. So it affects the surface of the root near the apex of the, apex or the crown in case of an impacted tooth. So mostly it affects sometimes the crown, sometimes the root, times both. So in radiographic features, the apex softened, flattened or in square shape, the foreman is that apex and opening can be seen, margins of the lesions are ragged and irregular because it will not be very clearly defined like internal resorption, it will be ragged and irregular. So variation in density due to varying rates of resorption and repair occurs on any external surface of the root. So external root resorption is associated with an infected pulp. So there will be a negative response to pulp sensitive test. So one more category we have that is inflammatory root resorption, okay. So inflammatory root resorption, that is the necrotic infected pulp provides the stimulus for periodontal inflammation. So the most common cause is trauma. So if the symptom has been damaged, leaving the dental tubules exposed, there is an open communication between the internal and external surface of the root. So bacteria and their byproducts diffuse through the dental tubules and stimulate an inflammatory response. So that is inflammatory root resorption. So basically the symptoms of tooth resorption, mostly it will be asymptomatic, sometimes there will be dull ache, discoloration, bad breath. So loosening of the damaged tooth also can be seen in some of the cases. So mainly the complication of tooth resorption, the first one is ankylosis, that is the main problem. That is the periodontal ligament will be destroyed and there will be fusion of the root and bone, direct fusion. So it is due to the excessive deposition of tissue during repair in the resting stages of resorption. So the ankylosis basically can be diagnosed by lack of mobility of the tooth and solid sound on percussion. So there will be very solid sound when we do percussion. So compared to the dull cushioned sound on the normal because it doesn't have a periodontal ligament or periodontal space. So if periodontal space is there, there will be a cushioned sound, that is a dull sound we can listen normally but if it is not there and the bone and tooth is joint or fused so we will get a solid sound. So how do we manage this tooth resorption? The first one is removal of the stimulant factor. So like pressure or infection, so such thing should be removed. If it is impacted tooth, it should be removed, if it is a tumor or any other thing. Then we need to go for pulpectomy or we can apply calcium hydroxide for 6 to 24 months as an intra canal medication because it has a good effect that is antibacterial effect in the root canal and it increases the pH of the dentine so thereby inhibits activity of osteoclast and acid hydrolysis. So in summary, identification of the stimulant factor is useful in order to render proper treatment by removing the etiological factor. So it is internal resorption is commonly asked, short not pink tooth also commonly asked. So if it is asked as a short essay, can write about the physiological, pathological, internal and external resorption and its features, its diagnosis and little bit about the treatment. So I will come up with a new topic in conservative dentistry, thank you.