 Hello everyone welcome back to another session in dentistry and more. So this topic is gingival tissue retraction methods. It comes under fixed partial denture. So as per GPT the definition of gingival retraction or displacement it is a deflection of the marginal gingiva away from the tooth. So it will be the tooth so we have marginal gingiva here. So we are going to reflect this marginal gingiva so we need to reflect this part. So we need to reflect it so that it will be more visible and we get a finer details of the cervical portion of the tooth. So that is gingival tissue retraction. So why it is so important in FPD that is it gives proper access to the prepared tooth then for the reproduction of the finish line. So finish line is what we see here because finish line is very much important in FPD. So there will be finish line it is a cervical part of the preparation. So reproducing the finish line and also to duplicate the sub gingival margins very accurately and providing the best possible condition for the impression material and also it helps in fluid control. So precision of the restoration for prevention of periodontal disease also can be a need of gingival tissue retraction. So there are two types of gingival displacement as possible one is lateral movement or lateral displacement another one is apical or vertical displacement. So this lateral displacement nothing but the tissue is deflected from the tooth okay laterally. So it helps us to take a proper impression because this impression material will be interfaced with the prepared tooth when it is deflected laterally. And another displacement is apical or vertical what it does is it exposes the uncut portion of the tooth apical to the finish line. So the problem is it may cause trauma of the gingival tissue followed by a recession. So we have four methods of gingival retraction the first one is mechanical okay so first one we have mechanical and the second one combination of chemical mechanical and the third one is ginger attached it is nothing but the rotary gingival cure attached okay and we have electro surgery these are the four basic methods and also we may have combination of any of the above. So we will start with the first one that is mechanical tissue dilation. So mechanical it is one of the first and earliest method used for physically displacing the gingival. Okay so this is our tooth and we have this is our gingival marginal gingival. So how do we displace using mechanical method the first one is impression material filled copper band or tube then rubber dam copper band then rubber dam then we have acrylic resin and like metal crown temporary metal crown so all these can be used to physically displace the tissue from the tooth. So this copper band or tube is nothing but we put a copper band which is filled with impression material like the copper band will be filled with impression material okay. So this copper band will be inserted here and it deflects the gingival okay so it will be deflected it will be deflected so it will be filled with the impression material. So we can use Gattavarsha impression compound elastomeric material or auto polymerizing resin as a compound which is filled in this. So the advantage is it is a good method to confirm the gingival margins that is in multiple abutments but the problem is it cause the injury to the gingival tissues and it create excess pressure so it can stipple the tissue from the tooth. The second method the copper this is a copper band the second method is rubber dam rubber dam as all we know we put for the restoration purpose the rubber dam isolation the same technique the main advantages are during the tooth preparation it exposes the finish line in a better way and also the impressions obtained are will be of good quality because of the better fluid control but the problem with the rubber dam is it is useful only when limited number of teeth in one quadrant are being restored and used in simple preparations with minimal sub gingival preparation it cannot be used on many teeth mainly on one quadrant it can be used. So the next one we have the acrylic resin a temporary acrylic resin coping is constructed and the inside it is relieved by 1 mm and adhesive is applied and elastomeric impression material is placed and re-seated the tissue is displaced when the material mechanically filled into the sulcus the same way but thing is we use acrylic resin coping. So a complete arch impression is subsequently made over the coping and it become as integral part of the impression so that is the acrylic resin so we can also use temporary metal crowns filled with thermoplastic stopping material okay so temporary metal crowns. So first we need to select a correct size trim to confirm to the gingival conduit and the margins then it is smoothened after that fill it with compound impression compound over the temperature and under occlusion pressure it is forced into the predetermined position. So the excess material from the gingival and will displace the free gingival then this material is trimmed without excessive pressure and cemented with temporary cement for 24 hours then final impression made in the next appointment okay so that is the temporary metal crown all these are using physical pressure that is where it is known as mechanical method to displace the gingival. So one is copper band, rubber dam, acrylic resin and temporary metal crown. We can also use one more method is there in mechanical that is strings or fibres okay that I forward to mention. So this plain cotton thread or unwaxed flows cotton cord or elastic retraction rings so plain braided knitted or any other type can be used wet or dry can be used to retract the gingival. So the second method we have chemico-mechanical one okay so the chemico-mechanical one the second method it is a mechanical aspect it is a combination okay so we have chemical method and also mechanical so the mechanical aspect involves placement of a string into the gingival sulcus to displace the tissue okay so we have a tooth here so first what we are doing is we keep a string around the gingival to displace the tissue so that part is mechanical part then the chemical aspect involves treatment of the string so treatment of the string with one or more number of chemical compounds that will induce temporary shrinkage okay that will induce temporary shrinkage and there will be control of hemorrhage and fluid seepage so the first part is mechanical there will be a string which will be inserted into the gingival sulcus then we apply some chemicals so that will induce temporary shrinkage of the tissue and control of hemorrhage and fluid seepage. So usually the cotton tools the size of flows are rolled into creamy mixture of zinc oxide cement and these several tools are placed in the sulcus we know 48 hours is recommended for placement but not more than 5 to 7 days but the problem is there will be circular hemorrhage during the packing okay so it is mixed with the chemical with the mechanical method using pressure being applied using a string so retraction code can be it can be twisted knitted braided type okay so that is chemical mechanical methods and there are various wrecks also being used for gingival displacement such as epinephrine that is 0.12 0.8 % epinephrine 100 % potassium alum sulphate and 5 to 25 % of aluminium chloride ferric sub sulphate then zinc chloride tionic acid so all these are chemicals used to retract the gingival so next method we have gingertage so that is nothing but the rotary gingival curatage so it is also known as troughing creation of a trough so a technique of using rotary diamond instrument to enlarge the sulcus so it involves preparation of the tooth sub gingivaly while simultaneously curating the inner lining of the gingival sulcus okay so we use this is gingival we use a diamond bar it will remove the portion of tooth sub gingivaly also the inner lining of gingival okay so this is a part of tooth and this is the inner lining of gingival so the goal is to eliminate the trauma from pressure and the need for electro surgical procedures so suitability of the gingival for gingertage is the absence of bleeding from probing and sulcus tip should be less than 3 mm and presence of adequate carat nice gingiva is very essential so that is a troughing or gingival dilation so the process is a trough is created that extends from the crystal height of the gingival so we can say this is a crystal height so this is a crest okay crystal height of the gingival to a point that is 0.3 to 0.4 millimeter apical to the finish line so finish line will be here so it is from the crest 0.3 to 0.4 apical to the finish line using a fully rectified current so indications are where the areas of inflammation and granulation tissue around the tooth in cases where it is impossible to retract the gingiva and also to enlarge the sulcus and also to control hemorrhage to remove irritated tissue that has proliferated over the finish line in all these cases we can opt gingertage but the main problem with gingertage is it is contraindicated in patients with cardiac pacemakers insulin pump and very fine marginal gingiva with little or no attached gingiva it is highly contraindicated and presence of inflamable anesthetics or other agents and there will be delayed healing due to debilitating disease and radiation therapy and the method next we have is electrosurgery electrosurgery which is also known as electropotry okay so this is actually a confusing term electrosurgery and electropotry because in electropotry which uses direct current okay but we are using alternative current so and during this electropotry the current does not enter the patient's body only the heated wire comes in contact with the tissue in electrosurgery the patient is included in the circuit okay patient is in the patient is in circuit but in electropotry the patient is not in the circuit only the heater wire comes in contact with the tissue the basic mechanism of action is control tissue destruction current flows through a small cutting electrode and it produces high current density and rapid temperature rise so cells directly adjacent to the electrode are destroyed due to the high temperature okay so we need to keep some tissue considerations such as keep the electrode in motion and we should have appropriate current setting larger the electrode greater the current required and five to ten seconds between the applications we need to leave tissue must be moist electrode must remain free of any tissue fragments and electrode must not touch any metallic restorations so the advantages are clear operating area without or no bleeding healing by primary intention lack of pressure to incise tissues and less tissue loss after healing but the main problem with electrosurgery is there will be a unpleasant order there will be burn mark on the root surface and it is not suitable for thin ginger okay so these are the four techniques used for ginger tissue retraction for the fpd construction okay in order to take a proper impression of the ginger area that is a finish line and the cervical area so we have mechanical methods and we learn the types such as rubber dam the temporary crown acrylic all those methods and we have chemical mechanical where the cord will be pushing into the ginger circus and later the chemical will be added then ginger dish using a rotary instrument and this is electro surgery okay so that's all about ginger tissue retraction methods hope you understood this concept so it is commonly asked short not or maybe a short essay okay so i'll come up with a new topic in prosthetics thank you