 Hello everyone, welcome back to another session in dentistry and more today. We have sharpening of ham instruments from our ham instrument sessions So as we all know over a period of time anything any sharp Blunt or it become dull because of its continuous use So these dull instruments or the dull cutting edges cause more pain it prolongs the operating time and It will become less controllable It reduces the quality and precision in tooth preparation So resharpening requires little time and is very rewarding so we have basically three types of Equipments to sharpen the instruments one is stationary Sharpening stones then mechanical sharpeners The last one is handpiece sharpening stones So stationary stones are block or stick of abrasive material Such as oil stones. They are stationary stones a cutting of oil is given to aid in sharpening process They are of coarse grit medium grit or fine grit in nature So course and medium grit stone they use for initial reshaping of a badly damaged instrument or for sharpening other dental equipments Such as bench knives. So cause a great use as little as needed for reshaping And then final sharpening done with a fine stone. So the fine grit stones sharpening dental instruments to be used for tooth preparation The stationary stones they can be flat grooved cylindrical tapered the flat one Useful sharpening instruments with straight cutting edge the cylindrical one with concave cutting edge the tapered Permit using a portion of stone with curvature matching that of instrument So it can be a natural or synthetic the stones So the four types of materials most commonly used the first one is Arkansas stone Which is naturally occurring which containing micro crystalline quartz It is semi translucent white or grain color, which is hard enough to sharpen steel but not for carbide instruments It is available in hard and soft varieties should be lubricated with Light machine oil before using should be covered in the thin film of oil and store Next one is silicon carbide Which is an industrial abrasive which is available as grinding wheels or sandpapers Which is hard enough to cut steel but not hard enough to sharpen carbide instruments, which is available in course and medium varieties Which is basically moderately porous require lubrication with a light oil to prevent cloggy The third one is aluminum oxide, which is being increasingly used now a days clothes and medium varieties are there Which is pickled tan or bromide in color Fine which is white less porous and it requires less lubrication The last one is diamond, which is the hardest abrasive most effective capable of sharpening carbide and Steel instrument diamond horns small blocks of metal with fine diamond particles impregnated in surfers held in place by electroplated layer of corrosion resistant metal Which is not porous, but Lubrication is required just cleave with mild detergent and medium bristle brush Mechanical sharpness nowadays hand sharpening is decreased because it requires a lot of energy And there is a lot of high-speed rotary cutting instruments The treatment honing machine is an example of mechanical sharpener Move a horn in a reciprocating manner at a low speed while instrument is held at the appropriate inclination and supported by a rest So what are the principles of sharpening one thing is the sharpened instruments only after when they have been cleaned and sterilized Established proper bevel that is 45 degree and the desired angle of cutting edge To the blade before placing the instrument against the stone and maintain these angles while sharpening So use a light stroke or pressure against the stone to minimize frictional heat And use rest or guide whenever possible remove as little metal from blade as possible and likely On the unbeveled side of the blade after sharpening to remove the fine bur that may be created After sharpening Raise sterilize the instruments along with other items on the instrument tray set up keep sharpening stones clean and free of metal cuttings So mechanical techniques blade is placed against the steady rest and proper angle of the cutting edge Of the blade is established before starting the motor light pressure of instrument against reciprocating bone Which it will which will be maintained with a firm grasp on instrument A trace of metal debris on the face of a flat horn along the length of the cutting edge Which is an indication that the entire cutting edge is contacting the horn which is a very quick method and hand piece stones used for instruments with curved blades Whereas a stationary stone technique Stationary sharpening stone at least two inch wide and five inch long Should be of medium grit thin film of oil lubricant placed on working surface 45 degree angle of weevil and cutting edge should be used to the stone So the rules are lay stone on flat surface and do not tilt the stone while sharpening Grasp the instrument firmly. Usually they're modified pen grasp So it will not rotate or change angles while we sharpen So to ensure stability during the stroke that is the sharpening strokes Use a ring and little finger as a wrist and guide along a flat surface or along the stone This prevents rolling or dipping of the instrument which results in a distorted and uneven bevel And use a light stroke to prevent the creation of heat and the scratching of the stone Use different areas of the stone surface while sharpening because This helps prevent the formation of glue on the stone That imbare efficiency and accuracy of the sharpening procedure So we have a test to check the Efficiency of the newly sharpened instrument that is By lightly resting the cutting edge on a hard plastic surface If the cutting edge digs in during an attempt to slide the instrument forward over the surface The instrument is sharp If it slides the instrument it is not sharp. It is still dull. It needs to be Redone Only very light pressure is exerted in testing for sharpness. It cannot be over emphasize that sharp instruments are necessary for optimal operating procedures So that was all about sharpening. So we learned sharpening test and various No sharpening instruments sharpening stones mechanical sharpeners and hand piece Sharpening stones we have stationary ones Basically four types of consas silicon carbide aluminum oxide and diamond And we have mechanical sharpness and principles of sharpening And stationary techniques and finally the sharpness test So that's all about the sharpening of the instrument. I'll come up with a new topic in the industry and more. Thank you