HISTOLOGICAL ZONES OF ENAMEL CARIES NEET MDS & INICET 3rd BDS ORAL PATHOLOGY

hi winners this is dr srikanth from team mds conquer now i'm going to discuss about the histological zones of enamel cares of course this is an important area for your university examinations a short answer in your third year and followed by an important area for entrance point of view okay hope you are very familiar with the histological jones of enamel curious and you can remember with a mnemonic a keyword called as td b s okay so you can remember just with this word called as t d b s okay so what is this tdb is t for translate zone d for dark john b for body of lesion s for surface layer so nowadays i hope like most of you are preparing for inic et2 so inact is going to ask a sequence based question so they can ask you what is the sequence of this histological enamel jones from inside outside or from outside to inside sometimes they may link with a diagram also very simple don't need to go for a complicated diagrams even you are planning to write a university exam okay either in your mds first year okay this is an important area or either in your third bds if a question is asked you can go with a simple diagram like this with different color coding okay so from inside to outside it is going to be t d b s okay so now we'll try to go a bit a bit deep into this particular concept so what what happens in each zone what is the significance of each and every john from an entrance point of view and of course you can write the same points for your theory question also so enamel carries zones are divided so you can remember with tdbs simple mnemonic so the zone one okay is called as translate zone t zone two is called as a dark zone and zone three is called as in a body of lesion and zone four is called as a surface zone and surface zone is present outside whereas your transient zone is present inside so any carry starts from the surface mostly like most except few carries most of the kerysis starts from the surface so surface is always present whereas the deepest layer may be absent in some types of histological slides that's what the point one says okay not always present and of course as it is the deepest zone it is going to be the advanced front means it is the one which is going to guide it it is something like an engine to the train it is something like an engine to the occurrence of a dental caries and of course it is the deepest of all the zones because it is present in the lower part and transcendency is because of the pores of the spaces with a volume size of one percentage do remember this is a volume size of one percentage is seen in the case of transient zone whereas a normal dentin has a poor size or a poor volume size of only zero point one percentage means this zone has ten times more pore size right so the second zone is called as dark john dark john is always called as positive zone okay it is called as positive zone it is usually present and i mean it is basically due to the reduction of the minerals per unit volume because basically demineralization occurs here okay so keris is nothing but a shift of uh a shift of this demoniation remuneration cycle towards the demon relations side that is the reason why the carriage occurs and if you see the pore size the pore size is two to four percentage and uh if you see like if you if you talk about the rapid advancing carries it will be narrow in the rapid advancing care is this zone and it will be wider in the slow advancing cares when a slow carries is slow it is wider kerys is rapid rapidly progressing carries it will be narrow and coming to the third zone that is called as body of the lesion body of the lesion is present superficial to the dark zone and it will be deep to the surface zone it will be deep to the surface zone and it will be superficial to that of the dark zone and if you take here the there is a large portion of demineralization when you compare with the dark join when you compare with the dark zone the portion of revelation will be high and if you see the pores i pour size or the poor volume also the poor volume also is very very high in the case of body of the lesion okay so ah and and you can check this this is a clinical significance okay shows an increase prominence in the trial fringes so this this can be asked as a question it was once given in the pga okay so shows i mean uh increasing in the prominence of shreya fridges is seen in the which of the histological joan of and i am curious is a question asked the answer is john three that is the body of lesion and coming to the last zone that is called as surface zone which is the outermost zone okay uh appears really unaffected okay sometimes like if you see subsurface demineralization okay hope you remember your clinical uh point that is called as white spot white spot lesion okay so white spot lesion is basically due to the subsurface means surface is intact but there will be demon relation subsurface so sometimes this surface may be unaffected in some types of sub surface demineralization okay due to greater degree of mineralization and fluoride concentration what is going to happen most of these lesions will be healed self-healed self-healed self-healing will be there okay they can be self-healed that is called as uh you can you can consider it as prevented industry means you don't need to prepare a cavity for this surface zone because the accessibility of this fluorides or your remineralizing agents will be very high on the surface so there are high chances that this area can be remineralized again if it is left untreated then the surface enamel get damaged and the cavity will be formed okay so the if it if it is not properly treated then it moves to the next level okay uh hope hope you can check your ic dust classification if you just correlate the clinical i see this there is something called as i see the scariest classification if you correlate that okay icdas 1 and icds 2 will come under surface areas okay the white spot lesion is nothing but it it moves around the surface zone and the treatment plan for icds 1 and icdhas2 that involves the subsurfaces remineralizing agents you can apply fluorides you can maintain proper oral hygiene you can apply remineralizing agents okay that is cpp acp calcium amorphous calcium phosphate can be applied so that icy does one ice dash through can be healed which are present on the surface zone