Endodontic treatment is one of the most complicated treatments in dental practice , this is due to the limitation in vision and the anatomical complexity of the teeth.
access cavity preparation is the most effective step in making the procedure workflow easy and minimise the stress during completing the other steps.
designing off the access cavity in a way free of any vision obstacles or over hanged dentin on orifices is important to facilitate locating of the canals orifices and in shaping them with stressless procedure on the files.
in order to have a clear and direct vision on the pulp chamber we must do the following:
-COMPLETE CARIES REMOVAL:
this will show you the restorability situation of the tooth and helps you to get an easy entrance to the chamber, caries removal should be done circumferentially from the outer surface towards the center of the tooth , as we know there are pulp horns which are the most coronal part of the pulp chamber and they are the first part of the chamber that effected by caries so after caries removal we can find the pulp horns easily which makes the entrance to the chamber easier.
-DESIGNING OF THE CAVITY:
this will give a tooth without unsupported enamel and makes the path of vision,all the angles should be rounded no sharp or undermined enamle should be left because they could be fractured easily between visits.
-KNOWING THE MAP OF CHAMBER DESIGN:
this will help in imaginary designing of the cavity after caries removal and localisation of the chamber position in mind,as we know every tooth has its own chamber design by knowing the chamber shape of the tooth that we are treating how it looks like this will gives us the ability to draw an imaginary map on the cavity we did, from the pulp horns we have we can initiate our access designing by connecting each pulp horns together making the shape of the chamber that we should already know from models for each tooth,this will give you a complete access with no roof covering the chamber,after roof removal again all sharp edges should be removed abd the wall of the chamber is continuous with the wall of crown with no overhang dentin on the orifices should be left because this will interfere with file insertion and motion inside the canal.
-RIGHT TOOLS:
to remove,design,refine,expose and locate what we are searching for,caries removal should be done with round or cylindrical burs(diamond burs used to remove caries from enamel and carbide burs remove caries from dentin) cylindrical or 102gc bur can be used in refining the cavity,EndoZ bur can be used to connect pulp horns and deroofing of the chamber because of its non cutting end which is harmless to the pulp floor,finaly we can ise a very sharp probe such as dg16 for orifice locating acoording to canal map and floor map of each tooth.
after all these steps we can now get a conventional straight and direct vision access cavity preparation which makes the procedure easier and joyful.
Thank you
Dr.Ahmed Hameed
B.DS
basra dental collage-Iraq
microscopic endo at ALFARIS dental clinic and ALHARRAN dental clinic
lecturer at idex Iraq and arabian endo series
