 So now we are in the second part. So this session is about the cells of Cementum and its functions and little bit about the developmental anomalies and other problems seen in Cementum. So we have two types of cells. They are Cementoblasts and Cementocytes. Cementoblasts are which is derived from dental follicle, okay hope you remember dental follicle giving rise to Cementum, Peridontolegamon and Alvulabon whereas Papilla giving rise to Pulp and Tentane. So the transformation of mesenchymal cells of dental follicle giving Cementoblasts. So these Cementoproginator cells synthesize collagen and protein polysaccharide. So these cells have numerous mitochondria, well formed Golgi apparatus and large amount of granular endoplasmic reticulum. So while seeing the histology the root resorption areas showing that the Cementoblasts can arise wherever viable dentine is exposed to the soft tissues of Peridontolegamon. So the induction of Cementoblastrum Peridontolegamon cells can apparently take place throughout the life as evidently as evidenced by the physiological areas of Cemental repair. So the Cemental repair will be happening throughout the life wherever there is loss of tissues happen or resorption happens the Cementoblasts will act and produce new Cementum. So cellular turnover among Cementoblasts is slow compared with that in the osteoblast. So the bone and Cementum are adjacent between these two we have Peridontolegamon. So the turnover rate is comparatively low in Cementum compared to the Alvulabon. Furthermore it appears that Cementoblasts are capable of altering the rate of Cementum deposition. Whereas the Cementocytes, Cementocytes in Lacune and the channels in which their process extents which are known as canalicule. So canalicule are the extended processes Cementocytes are seen in Lacune and the central cell mass may appear round or oval which is having 8 to 15 micrometer and the cytoplasm is padley basophilic and the nucleus is centrally located which has a central nucleus with basophilic cytoplasm. So Cemento enamel junction is another feature we know what is Cemento enamel junction it is the boundary between the tooth crown and root in clinically but anatomically it is a junction between enamel and Cementum. So it has basically 4 types the first type is Cementum overlaps enamel the Cementum overlapping enamel 60% is second one is Cementum meets at a point Cementum and enamel meets at the cervical end and 10% enamel and Cementum does not meet and 1.6% that is the least where the enamel overlaps Cementum that is the least percentage most common is Cementum overlaps enamel. If the Cementum is not meeting enamel there will be exposed dentin because root dentin is covered by Cementum so exposed dentin means there will be chances of hypersensitivity. So CEJ can be located various methods like conventional modified tactile, bivisual method using probes, bite wings, RVG so we can use many probes like fluorida probes, periopropes so many probes are there to locate CEJ. So another junction is Cemento-Dentinal junction so it is a terminal apical areas of Cementum where it joins the internal root dentin is called as Cemento-Dentinal junction okay the apical area of Cementum this is apical area of Cementum where it joins with the internal root dentin so it joins with the internal root dentin is on a Cemento-Dentinal junction. So the nature of CDJ is of particular importance because it forms an interface between two very different mineralized tissues, okay these are the two mineralized tissues, cementum and dentine and it is also of clinical importance because of the processes involved in maintaining tooth function while repairing a deceased root surface. So it is of clinical importance because it has repairing functions involving repairing of a deceased root surface. It is 2 to 3 micrometer. Now let us move on to the functions. We have three basic functions, anchorage, adaptation, repair and resorptions. In anchorage it is to furnish a medium for the attachment of collagen fibers that bind the tooth to the alveolar bone. So the connective tissue attachment to the tooth impossible without cementum, okay so we know that periodontal fibers are giving anchorage. So it is attaching to the cementum. So without connective tissue it is not possible. So in hypophosphatasia where the phosphatasia the element of cementum is missing, loosening and premature loss of anterior deciduous teeth occurs that itself showing that without cement there is no possibility of anchorage and exfoliated teeth are characterized by an almost total absence of cementum, okay. So that is a clinical evidence of cementum and its anchorage. Whereas adaptation the second one it is a continuous deposition of cementum is of functional importance because cementum is not resorbed under normal condition. As most superficial layer of cementum as age increases a new layer is deposited that keeps attachment apparatus intact. So a new layer will be continuously deposited it is happening throughout the life. The repair process it is a major reparative tissue for root surfaces. So damage to roots such as fracture resorption can be repaired by the deposition of new cementum. And resorption of cementum. Cementum although is less susceptible to resorption than bone but it is carried out by multi-nuclear Odentoclast. So sometimes question might ask what is the functions of Odentoclast it is a multi-nuclear to transfer it causes destruction or resorption and may continue into the root ending. So what are the factors of resorption? So we have local factors and systemic factors. Local factors are trauma from occlusion, orthodontic movement, pressure from malaligned erupting teeth, cysts, tumors, teeth without functional antagonist if proper antagonist is not there that also chance of resorption. Embedded teeth replanted and transplanted teeth, periopical and periodontal diseases whereas the systemic factors calcium deficiency it could be due to hypothyroidism, hereditary, fibrous, osteodystrophy, Paget's disease and also could be an idiopathic reason. So cementum resorption appears microscopically as bare like concavities on the root surface so these multi-nucleated giant cells and large mononuclear macrophages they are generally found adjacent to the cementum which is undergoing active resorption. Okay so resorption occurs most commonly in the apical third than middle third and ginger third so here it is a most common site of resorption so it is always associated with multi-nucleated giant cell I said Odentoclast or cementoclast. Now let's see few anomalies we have covered in detail about the anomalies but especially the cementicals so cementicals are small globular masses of cementum which is found approximate in around 35 percentage of foment roots so may not always be attached to cementum surface but may be located in free as a free appearance in paranormal ligament though these may be result from micro-trauma when extra stress on sharpies fibers cause a tear in the cementum and they are more commonly found in the apical and middle third of root and also in root percussion areas and it may develop from calcified epithelial rest and as by specules of cementum or alveolar bone when it is traumatically displaced. Next one is enamel pearl we have seen so in some of the hard week epithelial root sheath cells remain attached to the forming root surface they can produce a focal deposit of enamel that is known as enamel pearl so which is plaque retentive structures which promote periodontal lysis they look like calculus but it is actually enamel pearl which cannot be scaled off we cannot remove it in scaling procedure and some of the abnormalities of cementum we have many abnormalities of most common one is cemental hypoplasia hypoplasia means over functioning so hyper cementosis or cemental hypoplasia it is abnormal thickening of cement there will be large amount of cementum compared to the normal one it is a largely an age-related phenomenon it can be localized one-tooth or maybe generalized affect the entire condition so if the overgrowth improves the functional qualities of cementum it is termed as cemental hypertrophy if the overgrowth occurs in non-functionality or if it is not correlated with increased function it is known as cemental hypoplasia okay so these are different what is cemental hypertrophy and hypoplasia different hypertrophies if the overgrowth improves the functional qualities of cementum that is not a problem it is it is improving its functional quality that is known as hypertrophy but if the overgrowth occurs in a non-functionality or if it is not correlated with increased function that is known as hyposementosis or cemental hypoplasia so it occurs as a generalized thickening of cementum with nodular enlargement of the apical third of the root it also appears in form of spike like cemental spikes created by either the coalescence of cementacles that are added to the root or the calcification of ferrodontal fibers at the site of insertion into the cementum it is usually associated with the situations like teeth without antagonist, teeth with pulpal and periapical infections so hyposementosis of entire condition may be seen in patients with pager's disease so pager's disease is a bone disease that is problem associated with the bone formation so in that case also hyposementosis can be seen in a generalized form so some of the other problems are seen hyposementosis are acromegaly calcinosis thyroid goreter arthritis and treatment is basically does not need any treatment it could pose a problem if an affected tooth requires extraction so if extraction we don't go for a normal extraction instead a surgical extraction is opted cemental eplasia or hypoplasia eplasia may hypoplasia means normal function is not happening so hypophosphatasia there is a absence or paucity of cellular cementum so hypophosphatasia is due to an inborn error of metabolism the basic disorder is a deficiency of enzyme alkaline phosphatase so due to that there is no proper cellular cementum or absence or paucity so this is characterized by loosening and premature exfoliation of deciduous teeth mainly anterior so cemental hypoplasia means there's no proper cementum so this angrage function is impaired so there will be loosening and premature exfoliation so exfoliated teeth microscopically show complete absence of cementum or isolated areas of abnormally formed cement. Cemental tear is another thing that is a detachment of a fragment of cementum is known as cemental tear the last one is ankylosis ankylosis is fusion of cementum and alveolar bone so cementum and alveolar bone will be fused and obliteration of the periodontal ligament space so if periodontal ligament space is not proper there will be fusion so results in resorption of root and and its replacement by bond tissue this condition is uncommon occurs in teeth without cemental resorption and it represents a form of abnormal repair so it can also occur after chronic periapical infection 2-3 implantation occlusal trauma and more common in primary dendition okay so this periodontal ligament space is obliterated so the cementum will be joined with alveolar bone so there will be very problem uh problem facing and extraction so clinically there will not be any physiological mobility and periodontal ligament space is replaced with bone in ankylosis so proprioception is lost teeth have special metallic percation sound so we can make out whether it is ankylosteron on by tapping on the tooth we will get a metallic percation sound so when uh cementum is exposed to the oral environment in cases of gingeral recession there will be and pocket formation there will be hypersensitivity so that's all about uh cementum so we were talking about the cell cemento blasts and cemento sites and we discussed about cemento enamel junction and its four types cemento dental junction and its various functions anchorage adaptation repair and resorption and the developmental anomalies associated with cementum that is cementicals enamel pearls cemental hypoplasia i told you what is hypoplasia and hypotrophy cemental hypoplasia or hyposemintosis cemental eplasia or hypoplasia that is hypophosphatasia and ankylosis so uh these are the short knots like cemento enamel junction is a short knot all these are short knot cementicals enamel pearls hyposemintosis and the functions of cementum and cemento blasts cemento sites are again could be a short knot so i'll come up with our next topic alveolar bone msx sessions hope you understood about the cementum cementum is a little uh small topic compared to our periodontal ligament and ginger but uh questions will be asked in the first session we had seen the cementum and its basic characteristics and the parts of cement that is cellular and cellular cement so i'll come up with alveolar bone in my next session thank you