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OBTURATING MATERIALS. CLASSIFICATION OF ROOT CANAL FILLING MATERIALS BY GROSSMAN SOLID CORE MATERIALS Metals Plastics Cements /pastes SEALERS Plastics Cements Pastes. SOLID – CORE MATERIALS METAL SILVER STAINLESS STEEL FILES AMALGAM PLASTICS GUTTA PERCHA Source Chemistry Phases
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CLASSIFICATION OF ROOT CANAL FILLINGMATERIALS • BY GROSSMAN • SOLID CORE MATERIALS • Metals • Plastics • Cements /pastes • SEALERS • Plastics • Cements • Pastes
SOLID – CORE MATERIALS • METAL • SILVER • STAINLESS STEEL FILES • AMALGAM • PLASTICS • GUTTA PERCHA • Source • Chemistry • Phases • Composition • Properties • Advantages • Disadvantages • Forms of guta percha • Medicated gutta percha • RESILON
Cement/paste Fills • Hydron • Endocal 10 (Biocalex 6.9) • Resorcinol – Formaldehyde resin • Mineral trioxide aggregate • Calcium phosphate
INSTRUMENTS USED FOR OBTURATION • Endodontic pliers • Paper points • Spreaders • Pluggers • Device for cutting gutta percha • Heat carriers • Spiral paste fillers
SOLID-CORE MATERIALS • METAL CORE MATERIALS
SILVER CONE • Introduced by Elmer A. Jasper in 1933 • Pure silver molded in a conical shape • Canal preparation • Tapered converging walls • Advantage • Stiffer than gutta-percha • Easier to insert in very narrow/ fine tortuous canals
Disadvantages • Poor lateral seal - cannot conform to the pulp space • Cannot independently seal root canal – cementing medium required • Corrosion of silver cones due to • Presence of small amounts of other trace metals (e.g. 0.1% to 0.2% of copper and nickel) • Loss of integrity of coronal restoration and exposure to saliva • Canal irrigants • Corrode by oxidation – surface compound –silver amine sulfate amide hydrate (SELTZERETAL) -Sulfur –blood ,saliva,bone, cementum. Corrosion products • Toxic • Localized argyria/ tattoo • Higher failure rates -overuse -degree of enlargement- not reached -necrotic,pulpal debris not removed • Difficulty in retrieving cones in case of retreatment
INDICATIONS • Mature teeth with small or well calcified round tapered canals • Maxillary first premolar with 2 or 3 canals • Buccal roots of maxillary molars • Mesial roots of mandibular molars • NOT INDICATED • Youngsters • Anterior teeth • Single canal premolars • Large single canals in molars
STAINLESS STEEL FILES • Originally suggested by Sampeck in 1961 • Used to fill • Fine, tortuous canals • Heavily calcified dilacerated narrow canals • Used instead of silver cones • Advantages • More rigid than silver cones • Inserted into a canal with greater ease • Less susceptible to corrosion
Disadvantages • Cannot independently seal the root canal, needs a cementing medium • Excess sealer collects in the flutes of the instrument rather than being forced against canal walls • Technique • Cementing one file • Handle cut off with a high-speed hand piece, 3-4mm below occlusal surface
OTHER METAL CORE MATERIALS • Gold (by Grove) • Iridioplatinum • Tantalum • Titanium (by Messing) • Amalgam
DISADVANTAGES OF METAL CORE MATERIALS • Require an absolutely circular canal preparation • Often bind in one or two places of the root canal wall, giving a false sense of fit • Radiographically are deceptive because they give a dense appearance to the root canal fill • Corrode when in contact with either periradicular tissue fluids or oral fluids, the corrosions products are highly cytotoxic • Cannot obturate the canal system three dimensionally, requires a sealer
SOLID-CORE MATERIALS • PLASTIC CORE MATERIALS
GUTTA PERCHA • The word ‘Gutta Percha’ is an English derived word from the Malay origin “Getah Pertja” meaning ‘strings of sticky plant juices’ Getah – gum Pertja – name of the tree in Malay language
SOURCE • Malays call it ‘TABAN’ • English call it ‘MAZER WOOD TREE’ • Also called ‘ISONANDRA GUTTA TREE’ • Scientifically called ‘PALAQUIUM GUTTA BAIL’
SAPODILLA FAMILY PALAQUIUM GUTTA BAIL (Malaysian trees) MANILKARA BIDENTATA (Brazilian trees) Difference in composition Chemically & physically identical Balata or Gutta balata Gutta percha
CHEMISTRY 1,4, - POLYISOPRENE TRANS FORM CIS FORM GUTTA PERCHA NATURAL RUBBER ~ 60% CRYSTALLINE FORM LARGELY AMORPHOUS FORM • Harder • Less elastic • Brittle
Phases of Gutta -Percha Bunn 1942 • Chemicall pure gp – two different crystalline forms -alpha (directly from trees) - beta (commercial gp) -converted into each other • Fisher D. 1953 gamma –unstable form - amorphous in nature
heated heated 540C to 600C 420C to 490C Cooled at a rate of 0.50C Normal cooling NATURAL GUTTA PERCHA Alpha phase crystalline form More linear structure More stable Boiled Beta phase Alpha phase molten melt High molecular weight Low molecular weight (Processed form)
EXPANSION <1% to 3% heated heated cooling cooling MORE SHRINKAGE Beta phase Alpha phase molten melt
Greater shrinkage when • More the phase changes • Higher the temperature • Compensated • Compaction of gutta percha
PHASES OF GUTTA PERCHA ALPHA PHASE • Natural tree product • Low molecular weight polymer • Lower melting point • Low viscosity • Increased stickiness • Less shrinkage (2.2%) • Newer products • Thermafil • MicroSeal BETA PHASE • Processed form • High molecular weight polymer • Higher melting point • Higher viscosity • Reduced stickiness • More shrinkage (2.6%) • Most commercial forms
COMPOSITION OF COMMERCIALLY AVAILABLE GUTTA- PERCHA Friedman 1975
PROPERTIES • Softens at a temperature above 64C • Easily dissolved in chloroform and halothane • Heat or solvent plasticized gutta percha, results in shrinkage of 1% -2% • Dental gutta percha when heated from 37o to 80oC and then cooled to 37oC there is a net loss of about 1.4% in volume relative to precycle volume at 37oC Schilder H. 1985 • 1mm thick gutta- percha has a radiopacity corresponding to 6.44 mm aluminium
AGING (by Sorin and Oliet) • Gutta percha oxidizes and becomes brittle when exposed to light and air • Prevention • Store in a cool dry place • Rejuvenation • Immersing cone in hot water (55C) for 1-2 sec and immediately immersing in cold tap water (22oC) for 5-10 sec ( Solomon M Sorin .J Endod 1979)
STERILIZATION OF GUTTA PERCHA CONES • 5.25% or 5% NaOCl for 1 min (vegetative microorganisms and spores) • Disinfected by • 1% NaOCl – 1min • 0.5% NaOCl – 5min • Hydrogen peroxide –3% • Chlorhexidine –2%(5min) After disinfection, gutta percha cones must be rinsed in ethyl alcohol to remove crystallized NaOCl before obturation
FORMS OF GUTTA PERCHA • CONES / POINTS • Core points (standard cones) • Auxiliary points (non – standardized cones) Standardized gutta percha cone Non-standardized gutta percha
Coloring agent – erythrosin Marciano,1993
Core points • Sizing based on similar size and taper as standardized endodontic files • Used as master cones
ENDO GAUGE or GUTTA GAUGE • Larger tolerance ( 0.05mm) than endodontic files (±0.02mm)
Auxiliary points • Have a larger taper pointed tip • Tolerance is 0.05 mm • Length - 30mm 2mm • Used as • Accessory points during lateral compaction • Master cones in warm vertical compaction and variable tapered preparations • Are also standardized but in a very different system
GUTTA PERCHA PELLETS / BARS • For use in thermoplasticized gutta percha • e.g. Obtura system • SYRINGES • As low viscosity gutta percha • to be coated on carriers • e.g. AlphaSeal, SuccessFil
PRE COATED CORE CARRIER GUTTA PERCHA • Stainless steel, titanium or plastic carrier precoated with alpha phase gutta percha • e.g. Thermafil • GUTTA PERCHA SEALERS • Dissolving gutta percha in chloroform / eucalyptol • e.g. chloropercha, eucapercha
ANTIBACTERIAL GUTTA PERCHA CONES • IODOFORM CONTAINING GUTTA PERCHA • MGP or MEDICATED GUTTA PERCHA (Lone Star Technologies, U.S.A) • Developed by H. Martin, T.R. Martin – 1999 • Contains 10% iodoform • Iodoform is centrally located –takes 24 hrs to leach to the surface • Remains inert until it comes in contact with tissue fluids that activate the free iodine • Antimicrobial activity against • Streptococcus viridans, sanguis • Staphylococcus aureus • Bacteroides fragilis • To be used with MCS (Medicated Canal Sealer), a Z0E sealer that also contains 10% iodoform
CALCIUM HYDROXIDE CONTAINING GUTTA PERCHA • - CALCIUM HYDROXID - CALCIUM HYDROXID PLUS (Roeko, Germany) - HYGENIC CALCIUM HYDROXIDE POINTS • Have a high percentage (40-60%) of calcium hydroxide in a matrix of bio-inert gutta percha • USES • Permit placement of medicaments betn apts • ISO standard sizes • Colour: light brownLength: 28 mm long
ROEKO's Calcium Hydroxid PLUS Points • greater release of Ca(OH)2 • more effective over longer period • Technique • Moisture in the canal activates the Calcium Hydroxide and the pH in the canal rises to a level of 12 + within minutes • Average treatment time is 1 to 3 weeks • Once Ca(OH)2 has leached out, the point is no longer useful as a filling material and must be removed • Available in • packages of 60 points each, ISO sizes 15 through 140 • 3 assortment boxes, 15-40, 45-80 and 90-140, 10 points each size
Advantages • Clean: • No smearing around the access cavity during insertion • Removable without any residue • Time-saving: • The points are ready to use • No mixing • Easy to apply • Easy to remove • Safe: • The insertion of the points down to the apex is easy • Ensures that calcium hydroxide is released throughout the canal
CHLORHEXIDINE – IMPREGNATED GUTTA PERCHA • ROEKO ACTIV POINTS (Roeko, Langenau, Germany) • Gutta percha matrix embedded with 5% chlorhexidine diacetate • For use as an intracanal medication • temporary root canal filling • prevention of reinfection • ISO shaped points • Radiopaque
Technique • An Activ point corresponding to the last used root canal instrument, or one size smaller, should be marked with the predetermined length and applied into the canal without condensation • A drop of moisture (e.g. sterile H2O) may be used together with the Activ point to accelerate the release of CHX • Further dissociation will be initiated by moisture flowing into the canal through the dentine tubules and apex
Advantage • Ease of introduction • It is firm for easy application yet flexible to follow the curves of the canal. • Ease of removal • It can easily be removed with tweezers or a probe even after 3 weeks • The stability of Activ point is not affected by the release of chlorhexidine in moisture • No residue is left in the canal
When chlorhexidine comes into contact with moisture it releases cations which combine with the anionic molecules on the surface of the cell walls of the bacteria causing osmosis to malfunction (Petereit & Kirch, W., 1998). • Did not possess an in vitro inhibitory activity against Enterococcus faecalis (Lui et al, 2004)
ADVANTAGES OF GUTTA PERCHA • COMPACTIBILITY • Adapts to the root canal walls • BIOLOGICALLY INERT • least reactive • minimal toxicity • minimal tissue irritability • least allergenic • well tolerated by periradicular tissues • DIMENSIONAL STABILITY • BECOMES PLASTIC WHEN WARMED • HAS KNOWN SOLVENTS • Chloroform • Xylol • DOES NOT DISCOLOUR THE TOOTH • IT IS RADIOPAQUE
DISADVANTAGES • UNDERGOES SHRINKAGE WHEN PLASTICIZED • DOES NOT POSSESS ADHESIVE QUALITIES • LACK OF RIGIDITY • UNDERGOES VERTICAL DISTORTION DURING COMPACTION • Needs a definite apical constriction / stop
RESILON(Resilon Research LLC, Madison, CT, U.S.A) • Thermoplastic synthetic polymer – based root canal filling material • Consists of Resin core material • polymers of polyester • Difunctional methacrylate resin • Bioactive glass Fillers and radiopacifiers • Bismuth oxychloride • Barium sulfate • Overall filler content 65% by weight
It is used in conjunction with • SELF – ETCHING PRIMER • EPIPHANY PRIMER (Pentron Clinical Technologies) • SEALER • EPIPHANY ROOT CANAL SEALANT (Pentron Clinical Technologies) • Dual curable resin – based sealer
Self etch primer Sulphonic acid terminated functional monomer HEMA Water Polymerisation initiater • Resin sealer Bis GMA ethoxylated Bis GMA UDMA hydrophilic difunctional metharcylate fillers
Performs like gutta percha and has the same handling characteristics • Is biocompatible • Also insoluble in water • Easily retrievable for retreatment purposes • Softened with heat • Dissolved with solvents like chloroform