 Hello everyone welcome back to another session on dentistry and more so we are continuing our sessions and the instruments so last session we finished the instrument design, instrument formula, the nomenclature and various classification. This session is about various instruments and its uses in operative dentistry. Mouth mirrors there are basically two types of mouth mirrors. The first one is the front surface reflecting and the second one is rear surface reflecting. The basic difference between these two is this rear surface reflecting shows a double image so you can see the picture here it shows a double image. It appears to be a little inside the mouth mirror so this is a front surface which is appears to be on above the case of that mouth mirror ring. Mouth mirror is a very commonly asked short knot. Now though it looks very easy there are many points to be written in mouth mirror that is two types of mouth mirrors and why it is different. So this flat mirrors that is this one most commonly used and preferred for most procedures. There are concave that is magnifying mirrors are also available in the market nowadays. So as I mentioned there are two types front surface and rear surface. So the rear surface has a reflective surface beneath the glass. Okay so that the image is actually seen through the thickness of the glass twice. Okay so this is a double image. So this can produce a double image when it is necessary to look at the mirror from an angle but the glass surface means that it is resistant to damage. The front surface mirrors produce a clearer image particularly at ankles but they are easily scratched and so care should be taken particularly during the cleaning and surly session because it is very prone to scratching and breakage. This is a little bit a protected which is present inside this casing. So the rear surface mirrors can be used for general purposes and for retracting the tongue and cheeks or reserving the front surface mirror for detailed examination. So this is a handle of mouth mirrors. There are many types of handles present. Next we have forceps and tweezers that all of you know what is the purpose of forceps and tweezers. We have cotton forceps, hemer strats, articulating paper forceps, tweezers are hand instruments with two narrow and pointed straight or curved beaks to grasp small objects. It is packed arms with a locking device which is joined at one end and other end remains apart. So it is basically helping us to carry things to and from the mouth carrying cotton rolls, sponge pellets and carrying saliva soaked cotton rolls from the oral cavity to the waist unit. And the locking tweezers, it has a locking device to maintain the beaks in a closed position until released. So this avoids the unnecessary anxiety of the operator at the possibility of slippage of whatever is carried by the tweezer. Next is a common restoring instruments such as mixing instrument, cement spatula, agate spatula. It is very easy one. All of you must be knowing spatula is flat and wide neaps with blend edges, straight shanks and it is made up of stainless steel and plastic double ended instrument like blend end for manipulating in pressure materials and the sharp end for mixing cements. So it is used for manual mixing of cements applied as powder and liquid. The problem when these types of question comes you might be knowing it very well but you won't get exact points because only the points will fetch your marks. So these are these the points like the types stainless steel plastic and the two ends one is double ended and the next one is sharp end. When you write all these points you get both marks. Now the packing instruments like amalgam carrier, it's a stainless steel instrument used for carrying mixed amalgam to the cavity. So there will be a hollow tip of an amalgam carrier which will be inserted into the mixed amalgam then it will carry to the cavity. Condensing instruments like amalgam condenser, mechanical is there, hand instruments is there, gold condenser also present. These hand condenser are double entered instruments with the neaps coming in different size one is small and one is bigger. We can use it depending upon the size of the cavity. So neaps will be of round elliptical dam and triangular, parallel rectangular, large, small, serrated, non-serrated types are there and we have burnishing instruments. They are rounded edges used to polish or burnish the surface of metallic restoration. Again it is also having various types ball, egg, apple shaped, conical, aglass, fishtail. Then we can use these burnishers to shape metal matric spam so that they impart more desirable contours to the restoration when we use it for the class 2 amalgam restoration and also to bend cast gold near the margins to narrow the gap between the gold and the tooth. Next we have carving instruments, hand instruments with a blade or knife used to contour the surface of filling material in their plastic state. So Holland back cover it is knife edged elongated by beveled one then the diamond cover, waltzy cover, discolored, cleared cover and epoxy cover. So Holland back diamond and waltzy blade is parallel to the long axis of the instrument and the other is perpendicular to the axis of the instrument. So instrument used for placing and condensing restorative material. Acid of 4 titanium nitrate instruments used for placing and shaping composite. This is a composite kit. The surface of the instrument is very hard and is not scratched by the composite filler particles. It is also resisting the composite sticking to it. So this is a flat plastic then the carving in instrument then the burnisher and plaza for the composite. Whereas this one stainless steel plastic instrument used when the materials are in its plastic state that is we can modify it we can mold it we can burnish it we can carve it. Okay once it is set it is no more a plastic nature it is completely a hard restoration. So stainless steel plastic instruments this is an Algam condenser then the burnisher carving instrument and a flat plastic instrument. Cutting instrument application we have excavators ordinary hatchet excavator the cutting edge of plate director in the same plane as that of the long axis of the handle. So it is used primarily on anterior teeth for preparing retentive areas and sharpening internal line angles mainly for the gold restoration. Whereas this one is hoe excavator the cutting edge is perpendicular to the axis used for the tooth preparation walls and forming line ankles commonly used in class 3 and class 5 preparation. The ankle former okay the ankle former used for sharpening the line ankles and creating retentive features in denting in preparation of gold restoration also used in placing bevels on enamel merchants. Whereas the spoon excavator which is very commonly used to excavate the caries and which can be used for carving amalgam and wax pattern blade is slightly curved and cutting edges are either circular or claw like shanks are bi-angle or triple angled to facilitate the accessibility. Now the important one is the shea cells they are primarily for cutting enamels straight chisel a straight shank and blade with bevel on one side primary edge perpendicular to the axis of the handle these are the straight shea cells shank and blade of chisel may be slightly curved primary cutting edge then plain perpendicular to the long axis of the handle and may have either a distal bevel or mesal bevel. Then the enamel hatchet a larger blade heavier and beveled on one side rather than the ordinary hatchet. So the cutting edge in a plain parallel with a long axis of the handle useful cutting enamel and comes as right or left types for use of opposite side of the preparation. Next we have Jinchevel Marginal Trimmer or GA-MT which is very commonly a short knot. It is nothing but to produce proper bevel on Jinchevel enamel margins of proximal occlusion preparation and this blade is curved and primary cutting edge is at an angle. So there are two types right and left type used for mesal and distal side. So the second number in the instrument formula if it is 90 to 100 we can use it for distal marginal or Jinchevel Margin 85 to 75 for the mesal margin 100 and 75 for inlay-onlay preparation with steep ginger bevel. 90 and 85 for amalgam preparation with Jinchevel enamel bevel that declined gingerly and used for rounding or beveling of the axial pulper line angle of two surface preparation. The pair with the end of the cutting edge farthest from the shaft forming an angle is termed as distal and used to bevel the distal marginal or accentuate a mesial axial gingerly angle. So this is the distal ginger marginal ridge where the cutting edge is farthest from the shaft. The cutting edge is this one this is far which is very far from the shaft compared to this one this is closer to the shaft. So the pair with the acute angle of the cutting edge is closest to the shaft is mesial. So this is mesial because cutting edge is closer to the shaft and it is used to bevel a mesial ginger margin or accentuate a distal axial ginger angle. So it is used in proximal box of plaster preparation with horizontal stroke to scrape the Jinchevel wall and margin used in vertical or chopping stock to plane a facial or lingual wall and margin. Other cutting instruments include knives like amalgam knives, gold knives for trimming excess restorative material on Jinchevel facial or lingual margins or trimming and contouring the classifier restoration and also to sharpen the secondary edges of on the heel aspect of the blade. So the sharp secondary edge on the heel aspect of the blade are very useful in scrape pull mode. So we have files that is used to trim excess restorative material which is used at Jinchevel margins and we can use a push or pull instrument. Discard cleoid is used principally for carving occlusion and under mean unset amalgam restoration. So the session was about various instruments which you are very familiarized but you need to have good points to write or to get marks. So this ginger margin trimmer is very commonly asked question. Chisel or hatchet excavators can be asked and this plastic filling instruments or the mouth mirror is commonly asked. So next we have the finger grasp, the grasp techniques and the finger rest. After that we have four hand retentistry. Okay I'll come with the finger grasp and hand rest in my next session. Thank you.