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Endodontic Materials. The main objectives of root canal therapy are: Removal of the pathologic pulp. Cleaning and shaping of the root canal system. Three dimensional obturation to prevent reinfection. Functions of irrigants.
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The main objectives of root canal therapy are: • Removal of the pathologic pulp. • Cleaning and shaping of the root canal system. • Three dimensional obturation to prevent reinfection.
Functions of irrigants Irrigants are used to clean the root canal and are used in association with the shaping instruments. Functions of irrigants include: Lubrication of instruments used to shape the canal. Flushing out of gross debris. Dissolution of organic and inorganic tissue. Antimicrobial effect.
Irrigants Ideal properties: Lubricant Antimicrobial Dissolve organic debris Flushing Biocompatible Cheap
Classification of irrigants Chemically inactive irrigants Water Saline Local anaesthetic solution Chemically active irrigants Sodium hypochlorite (NaOCl). Oxidizing agents as Hydrogen peroxide (H2O2) Chelating agents as EDTA.
Irrigants Use Adequate volume required Stays within the confines of root canal Never deliver with excessive force Apical extrusion results in pain and possible swelling. Use luer-lok 27 gauge endodontic needle Efficiency enhanced with ultrasonic, sonic and mechanical instruments
Sodium hypochlorite 0.5-5.25 % Antibacterial Dissolve organic matter Corrosive/caustic Low toxicity Apical reaction Rubber dam
Hydrogen peroxide 3% +/- NaOCl Production of O2 eliminate anaerobes Bubbles may prevent adequate contact of irrigant with debris Limited shelf life
Chlorhexidine Hibisrcub(HIBISCRUB is an antimicrobial preparation for pre-operative surgical hand disinfection, antiseptic handwashing Usually used in 0.2% concentration Antibacterial, Substantivity. Flushing Lubricant Does not dissolve organic debris
Chelating agent Ethylene DiamineTetracetic Acid “EDTA” (File-eze, RC Prep) Remove smear layer allowing cleaning of tubules Soften dentine Not antibacterial File-eze is water soluble unlike RC Prep which contains carbowax and is difficult to remove
Irrigants Sterile water Local anaesthetic Saline (0.9%) They only provide lubrication and gross debris removal functions.
Intracanalmedicamanets If root canal treatment can’t be finished in a single visit, root canals are dressed with medicaments. Functions of intracanal medicaments: Primary function: antimicrobial activity Antisepsis(is the destruction or inhibition of (slowing the growth of) microorganisms ) Disinfection(Cleaning an article of some or all of the pathogenic organisms which may cause infection ) Secondary functions Hard-tissue formation Pain control Exudation control Resorption control
Intracanal medicament Ideal properties Antibacterial Penetrates dentinal tubules Control exudation or bleeding Biocompatibile. Eliminates pain Induce calcific barrier No effect on temporary Radio-opaque Does not stain tooth
Calcium hydroxide Hypocal(contains calcium hydroxide and barium sulfate) Ca(OH)2, 34-50% Ba SO4,5-15% Methylcellulose. Antibacterial (pH>12) Denatures protein Synergestic with NaOCL Cytotoxic-local necrosis, calcific barrier Cheap Dries weeping canals
Antibiotics Combination of drugs required to be effective Resistant strains becoming more difficult to treat Allergies
Steroids Triamicinolone, prednisolone Pain relief but no evidence of more effective than Ca(OH)2 ?use in root resorption by inhibiting odontoclasts ?depresses the host inflammatory response Not antibacterial but can be mixed with Ca(OH)2 Ledermix= triamicinolone+ tetracycline
Phenol based agents, Aldehydes and Halidyes Phenol, parachlorophenol(PCP), camphorated mono PCP, cresol, creosote, formacresol and chlorine. Antibacterial agents. Highly toxic agents. Possible mutagenic and carcinogenic effect.
Obturating materials Ideal properties of root canal filling materials: Antimicrobial Biocompatible. Good flow Adhesive in nature Dimensionally stable Not affected by moisture Radio-opaque Good handling Easily removed, post prep or retreat Does not stain dentine Cheap
GuttaPercha Guttapercha “ Isoprene” (C5H8) is one of the oldest and most common root filling material in use today. A natural latex produced from a genus of tropical trees Polymers of isoprene: Cis-natural rubber Trans-guttapercha.
Guttapercha points used in clinic consists of: Guttapercha 20% Zinc oxide 60-75% Metal sulphides, waxes, resin, opacifiers Guttapercha is available in 2 phases; Alpha and Beta.
Guttapercha taken from trees is in Alpha phase. Guttapercha in points used in the clinic is in Beta phase. Both phases differ in Melting temperature, volumetric changes and flow characteristics when molten.
Guttapercha Advantages of guttapercha: Biocompatible Dimensionally stable Compactable Easily removed Cheap Disadvantages of guttapercha: Does not adhere to dentine Lacks rigidity
Metal points • Silver (gold, tin, lead and titanium have been used) • Introduced in 1930’s • Silver preferred due to antibacterial effect • Rigid, unyielding • Impossible to adapt to canals • Poor seal as canal not commonly circular in shape • Corrosion • Difficult to remove for post • Titanium- biocompatible and avoids corrosion
Sealers Sealers are used in association with Guttapercha. Functions of sealer Cementing (luting, binding) the core material (guttapercha) into the canal. Filling the discrepancies between the canal walls and core material Acting as a lubricant to enhance the positioning of the core filling material Acting as a bactericidal agent
Root canal sealers Most sealers are toxic when freshly mixed Toxicity substantially reduced when set Most sealers are absorbable to some extent when exposed to tissue fluid Ideally sealer should flow backwards out of the canal However, no evidence that apical extrusion reduces success rate providing preparation and obturation are meticulous
Zinc-oxide eugenol Grossmans, Tubliseal Antibacterial Radio-opaque Slightly toxic when freshly mixed. Good flow and working time Does not adhere soluble
Calcium hydroxide based sealers Sealapex, Apexit Radio-opaque Soluble Biocompatible Preserve vitality of pulp stump and promote healing Does not adhere
Resin based sealers AH26, AH Plus, Endorez, Epiphany, RealSeal. Adhesive Antibacterial Toxic when freshly mixed Show setting shrinkage when set
Glass-ionomer based sealers Ketac Endo and ActiV GP. Mildly antibacterial Adheres to dentine Slightly soluble Unset GIC is cytotoxic but when set this reduces with time Very difficult to be removed
Silicone based sealers Roekoseal sealer. Slightly expands when set. Addition type silicone. GuttaFlow is Roekoseal sealer with added guttapercha particles. Does not adhere to root canal.
New root canal filling materials Resilon: resin-based cones. Similar in appearance and handling to guttapercha cones. Used with any resin-based sealer. Endorez cones: resin-coated guttapercha. Used with endorez sealer or any other resin-based sealer. ActiV GP: glass ionomer coated guttapercha. Used with glass ionomer based sealers.
Retrograde root filling materials Ideal properties Seals apex Biocompatible Ease of handling Moisture and blood tolerant Low solubility Radio-opaque Good tissue response Bonds to dentine
Amalgam Corrosion Apical inflammation Poor sealing ability Mercury toxicity
IRM Modified zinc oxide-eugenol Seals better than amalgam Need high powder to liquid ratio to decrease toxicity and solubility Short working time
Super EBA Modified zinc oxide-eugenol High compressive and tensile strength Neutral pH Low solubilty Not affected by blood Good tissue response
Composite Problems with moisture control Some good results in sealing ability but further work required
Glass Ionomer Cements Bonds to tooth substance Biocompatibilty (Toxicity reduces when set) Some antibacterial properties Seal superior to amalgam
New materials Diaket (Tricalcium phosphate paste) Polyvinyl resin Good tissue response ?cementum forming Mineral Trioxide aggregates (MTA) Seals better than amalgam or super EPA Not adversly affected by blood Marginal adaptation better than amalgam, IRM or super EBA ?cytotoxicity Laser Hydroxyapatite
MTA Mineral trioxide aggregate: Pulp capping Nonsurgical apical closure Perforation repair Surgical root end filling