18. DRUGS USED IN DENTISTRY I .pptx

DRUGS USED IN DENTISTRY I: Bleaching, Disclosing, Desensitization agents Dr Nadia Halib (BSc., Phd, UKM) Department of Basic Sciences & Oral Biology, Faculty of Dentistry, Universiti Sains Islam Malaysia Learning objectives Identify drugs that are commonly used in dentistry. Describe their ch...

DRUGS USED IN DENTISTRY I: Bleaching, Disclosing, Desensitization agents Dr Nadia Halib (BSc., Phd, UKM) Department of Basic Sciences & Oral Biology, Faculty of Dentistry, Universiti Sains Islam Malaysia Learning objectives Identify drugs that are commonly used in dentistry. Describe their characteristics (clinical uses, adverse effects, toxicity). Describe the probable mechanisms of action of the drugs. ASTRINGEN T AND OBTUNDEN TS  ASTRINGENT Agents that precipitate superficial protein when apply to the skin @ mucous membrane Chemical compound that tends to shrink or constrict body tissues Arrest capillary oozing, promote clotting and precipitate proteins on the bleeding surface. The different types of astringents used in dentistry are: Tannic Acid Zinc Chloride Zinc Sulphate Copper Sulphate Alum Tannic Acid A vegetable astringent from nutgalls. It precipitating protein and gelatin as tannates (salt or ester of tannic acid) owing to its acid radical. Tannic acid preparations - used as astringent mouth wash, astringent dentifrices, local haemostatics, mummifying agent and obtundent. Other vegetable astringent : catechu is also used as an astringent mouthwash. Zinc Chloride It is a caustic (corrosive) astringent Used as 5-10% solution in ulcerative gingivitis, pyorrhoeal pockets and apthous ulcers. Zinc Sulphate It is used as astringent. 0.5-1% concentration in the form of mouthwash and lotion in mastoiditis, stomatitis and chronic alveolar abscess. Copper Sulphate It is used as astringent mouth in 0.5- 2% concentration in indolent ulcer of gums. Alum It has an astringent, antiseptic and haemostatic properties. Used in 1-2% concentration to harden the gum or for inflamed and ulcerated gums. Certain other metallic astringents e.g. ferric chloride solution, lead acetate, silver nitrate. OBTUNDENTS Agents that diminish dentine sensitivity. Use to make excavation painless. Due to the availability of local anaesthetics e.g. xylocaine for painless excavation, the use of obtundents is very limited.  Class of Obtundents Classified into three according to their mechanism of action. 1) Act by destroying the nervous tissue ⮚ Absolute alcohol 2) Act by paralysing the sensory nerve endings ⮚ Phenol creosote ⮚ Benzyl alcohol ⮚ Camphor ⮚ Thymol ⮚ Menthol ⮚ Eugenol (clove oil) 3) Act by precipitating proteins ⮚ Silver nitrate ⮚ Zinc chloride Ethyl Alcohol Ethyl alcohol (70%) is nontoxic to the pulp and penetrates rapidly. It does not cause staining. Applied locally. (* allow the alcohol to evaporate and carry out the extraction). *Phenol On local application, it causes irritation followed by numbness. It is used alone and in combination with chloroform and olive oil in a 2:4:10 ratio. It acts rapidly but does not penetrate deeply. *Creosote Its characteristics and action is same as that of phenol. Penetration is relatively more. *Benzyl Alcohol Due to its local anaesthetic property it is used as obtundent agent. It can be used either alone or in combination of chloroform and ethyl alcohol in a 5:3:2 ratio. *Camphor, Thymol, Menthol All three are volatile oils and are used in a mixture in a ratio of 1:2:1 for rapid action. The mixture acts initially stimulating and then paralysing the sensory nerve endings. Eugenol (Clove Oil) Clove oil is used due to the presence of eugenol as its main constituent. It acts by paralysing the sensory never endings. It is non-irritating but give yellow stains. *Silver Nitrate It is an astringent and cause pain on application followed by desensitization. It acts by precipitating dentine proteins and liberating acid and stains the dentine black. *Zinc Chloride Its action is similar to that of silver nitrate but it causes sharp pain. Does not stain the dentine. MUMMIFYI NG AND BLEACHIN G AGENTS  Used to harden & dry the tissue of pulp and root canal so that tissue may maintain an aseptic conditions. MUMMIFYI To prevent infection, especially in cases where it is impossible to remove the pulp and contents of NG the root canal completely. AGENTS Mummifying agents are used in the form of paste or semi-liquid preparation like tannic acid glycerine. The following are mummifying agents used in dentistry: Tannic Acid It is used along with glycerine and it hardens the tissues and precipitates proteins and thereby avoids bacterial action. Paraform PARAFORMALDEHYDE It is a prodrug used in combination of zinc oxide or zinc sulphate glycerine and creosote and act by slow liberation of formaldehyde. It is also used alone as obtundents. Its main disadvantage - formaldehyde may penetrate the pulp and can cause inflammation. Formaldehyde is also used in the form of paste with zinc oxide, glycerine along with local anaesthetic. It hardens the tissue without causing the shrinkage. Iodoform It acts by slow liberation of iodine and has both antiseptic and local anodyne (substance that relieves pain) properties. It is used in the form of paste which contains tannic acid, phenol, eugenol (clove oil), cinnamon oil and glycerine. Toothache Drops These are the preparations used for temporary relief of toothache. Application - small pledge of cotton soaked with the product into the tooth cavity. Certain local anaesthetic compounds (benzocaine, eugenol or clove oil, camphor, menthol, creosote and alcohol) has been considered safe and effective for toothache. Restricted its use only for first aid type or temporary relief.  BLEACHING AGENTS Bleaching agents are used to remove pigmentation of teeth. They are classified as (i) Oxidizing agents e.g. perhydrol, pyrozone, sodium peroxide (ii) Reducing agents e.g sodium thiosulphate (iii) Chlorinated lime (iv) Ultraviolet rays Oxidizing Agents Hyrdrogen peroxide in various percentage. Perhydrol (30% H2O2 in water) Sodium peroxide (50% aqueous solution) are used as oxidizing agents to remove pigmentation of teeth. Reducing Agents Saturated solution of sodium thiosulphate is used to remove superficial stains with silver, iodine or permanganate. Chlorinated Lime It is a chlorine compound, used to remove the pigmentation of teeth. It is also used clinically by packing into the cavity as a dry powder. Ultraviolet Rays To bleach the dentine from a carbon or mercury, arc lamp UV rays have been used. *Other agents used to remove pigmentation of teeth Weak ammonia solution - remove iodine stains. Hypochlorite or iodine solution - remove silver & iron stains. Chlorinated lime and acetic acid - remove dye stains.  STYPTICS (LOCAL HAEMOSTATICS) AND DISCLOSING AGENTS STYPTICS (LOCAL HAEMOSTATICS) After tooth extraction and other dental procedures, bleeding occurs due to disruption of arterioles. Styptics or local haemostatics are used to arrest bleeding, or to control oozing of blood form minute blood vessel By the formation of an artificial clot, or by providing a matrix which facilitates clotting. After extraction of tooth, bleeding from the tooth socket is generally controlled by a cotton gauze pressure pack which may be aided by use of local haemostatics. (i) Gelatine sponge It is used for packing wounds after moistening with normal saline / thrombin solution. Completely absorbed in 2 - 4 weeks Cause no foreign body reaction. Gelatine sponge is available with 5% colloid silver (GELATAMP). Facilitates optimum wound treatment when applied to a surgical cavity. Can be cut to the required size (fit into smaller wound cavities /tooth socket after tooth extraction).  The evenly porous foam structure - absorbs its own weight in blood several time over Promotes thrombocyte aggregation due to large surface and fills the wound cavity. It remains in the wound and is completely absorbed within four weeks. The addition of colloid silver has an antimicrobial effect whilst being nontoxic and these type of preparations can be easily gamma sterilised.  (ii) Fibrin foam Fibrin foam or sheets are prepared from human plasma. These dried sheets are used to cover or pack the bleeding surfaces where it gets absorbed in the body. It is applied directly to the bleeding area and it is also combined with thrombin. (iii) Human or bovine thrombin- Dry powder or freshly prepared solution of human or bovine thrombin can be applied on the oozing surfaces. It is employed in haemophilia, skin grafting and in neurosurgery. Thrombin solution with fibrinogen is also used locally to induce clotting. (iv) Oxidized cellulose It is a surgical gauze, specially treated to promote clotting by reaction between haemoglobin and cellulosic acid. Since it is not well absorbed it is used only for surface haemostatics. (v) Vasoconstrictors Adrenaline (1% solution) is used in the form of cotton gauze pack in the bleeding socket. It stops bleeding by causing local vasoconstriction and useful in epistaxis. (vii) Astringents Tannic acid (20% in glycerine) is used for bleeding gums and bleeding piles. Tranexamic acid, ethamsylate etc. are - also used in the prevention and treatment of capillary bleeding in epistaxis, haematuria and after tooth extraction. DISCLOSING AGENTS A dye used in dentistry as a diagnostic acid Applied to teeth to reveal the presence of dental plague. Erythrosine Erythrosine tablets are dissolved into a solution or chewed to dissolve in the mouth. It stains the plaque area red but also may stain soft tissues. It is the most widely used disclosing agent. Fluorescein Dye Fluorescein dye stains the plaque yellow. It does not stain the soft tissues. But special light is required to see the stained plaque. It is more expensive. Two Tone Dyes A solution containing a combination of two dyes. Mature plaques stained blue. New plaques are stained red. ADVANTAGES- They help to differentiate mature and immature plaques. They do not stain the gingival tissues. Iodine Containing Solutions They have been used as disclosing agents but have the disadvantage of causing a high incidence of allergic reactions. Also have unacceptable taste → hence not preferred. THANK YOU