Dental Material and Laboratory Procedure PDF

Dental material and laboratory procedure Day 1 - 2 Mechanical Properties Force cause physical change through energy and strength. - - Create stres...

Dental material and laboratory procedure Day 1 - 2 Mechanical Properties Force cause physical change through energy and strength. - - Create stress or strain Stress - Reaction within material that cause distortion Create stress and strain - Strain of stress change in product in result - of stress and strain Types Tensile stress - pulls and stretch material Compressive stress Pushes materials together Eg chewing -. snear stress - Breakdown over sliding of two materials Ductility and Malleability withstand permanent deformation tensile Measure a metals ability to. Using or compressive force. Ductility Material tensile force without fracturing to change shape by pulling or. malleability Material to be extended by compressive force. Change shape to thin sheet or plate, Thermal properties (contraction/expansion) (cold) Hot to cold food/drinks within sudden contraction and seconds causing - expansion (Hot) - Restorative materials pull away from tooth. Cause microleakage or cracked tooth. Microleakage occurs during temperature changes. Dental material will contract and expand. - separation of material to tooth could allow fluids debris , , and microorganisms to enter material and wall of between cavity preparation. Percolation Process of liquid substance slowly passing through porous substance Application properties (Flow , adhesion retention , , curing ( Flow Dental material should have proper flow (pliable/soft) to fill in preparation - of teeth. Adhesion - Proper adhesion to prevent microleakage and loss of restorations. Force adhere to each other. - causes unlike materials to Affects adhesion process. Wetting Liquid (saliva) to flow over surface. - Viscosity Property of liquid to not flow easily -. of liquid flow of and ability a to is described in terms wetting viscosoty. Surfacharacteristics Liquid flows surface easily on a rough surface than on a very smooth. Film thickness Thinner the film adhesive junction. , stronger - 25 microns  Retention Hold two things firmly when they will not adhere to each other curing Setting process by chemical reaction or light in a blue wave spectrum. auto cured - hardens by chemical reaction mixing together mixed and placed and must be within working setting time -. Light cured Only hardens under curing light Dual cured As soon as base and catalyst is mixed -Final cure must be under curing light Dew Point - Water or moisture is created of - Temp changes , when moisture is deposited as droplets. water 1-s of Day 1 of -P age notes (only * notes Electrical properties (galvanic) or shock two different or dissimilar metals are present in the oral carity. Saliva (containing sal It is good electrical conductor - a two different metals (metal fillings ( - Solubility (dissolving ( - substance will dissolve in a given amount of another substance. (liquid ( Eg Material in oral that dissolves will wash -. cavity easily away and leave tooth structure exposed. Sugar-high solubility sand-low solubility  corrosive properties Reaction of metal in contact with temperature and a humidity saline. - , , - food can cause corrosion of dental material only surface discoloration - Most Corrosion is ↑ Page 1-5 of what was not marked DT Direct Restorations -Material applied directly to the tooth. Material is pliable and can still be adapted , carved , + finished Dental models reproductions of teeth of soft tissue are surrounding patients in mand , and max , arches. Dental amalgam alloy powder mixed with mercury - Technique of and Eames : one to one ratio alloy - mercury. 143-54 % of mercury equal to 46-57% of alloy powder - Soft pliable mixture. Placed in tooth , condensed , carved and hardened Mixture hardens to permanent amalgam filling -. Composition of amalgam powder allow. 3 65 % Silver-strength Tin = workability and strength 29 % 6% * % Copper = strength and corrosion resistance Zinc suppress Oxidization 2% Indications of using amalgam - Small to medium sized cavities in post , teeth. - Patient has poor oral hygiene - Foundation of metal-ceramic , cast metal , and ceramic restorations Severe destruction of tooth structure - Primary and teeth. problem is control - permanent moisture - Contradictions of using amalgam patients with allergy to mercury amalgam components - or large restorations is needed and restorative materials is not significant factor - a esthetics are important -  Amalgam Composition alloy mixed with mercury - soft pliable - mixture & -placed in tooth , condensed , carved , and hardened to a filling Physical Characteristics Mercury Liquid at room temperature - Highly poisonous-nausea headache , and - , swollen glands. Mercury absorption - skin contact and inhalation of vaporized mercury -. heat vaporizes with - of advantages mercury - Best restorative material for post teeth - "User friendly" readily mixed , placed , and carved on to teeth. High strength and withstand biting forces. - compression Resist recurrent decay better than composite resin. - last time. very long - of Disadvantages mercury colour not aesthetically pleasing does not match natural tooth - - considered contains so dangerous. - mercury Personal Hygiene face after avoid touching hair handling - or wash hands - Mercury combines with silver and gold. ( Jewelry Store sealed containers - in , and unbreakable. Preparation amalgam is supplied of in single alloy powder - use capsules. Includes proper ratio and mercury (separated by membrane ) - One side alloy powder. One side thin amalgam. of alloy 600mg - = small restorations of alloy 800mg Larger restorations - = Trituration of and form amalgam. process mixing alloy mercury to = - Direct application of amalgam. Mixed placed in well. 1 amalgam amalgam. 2 Amalgam carried to tooth preparation.. 3 Amalgam placed in increments in prepared tooth. 4. each increment is condensed immediately to remove excess mercury. to into 5. Carvers carve anatomy amalgam. Burnisher to smoothen 6. amalgam , 7. New restorations occlusal is checked.  Composite Resin. Properties of composite resin - Withstand environments of oral carity. Match natural tooth colour - easily shaped to anatomy of tooth. = Can bonded directly - be to tooth. Indications of composite resin - For Class 1-5 restorations Restorations for surface defects hypocalcification attrition abrasion , and such as congenital - , , abnormalities. Closure of diastema - Esthetic of teeth laterals. - such recontouring as peg ContraIndications - esthetic is not an important factor Patient hygiene especially in posterior teeth. - has poor oral , - cost of restorative material is an important factor in the treatment decision. Composition ↓ Material fluid material Dimethacrylate Fluid used. Organic Resin like AKA BIG-GMA monomer -. 1 is not restorative material. to make synthetic resin. Alone strong enough to use as fillers to restorative materials (Quartz glass, silica, coolants (. 2 Inorganic add strength -. , stronger by chemically filler to. 3 Coupling agent makes resin bonding resin matrix -. 4 Pigments Inorganic substance to match restorative material to tooth- -. of Types composite. 1 Molars / Macrofilled : Conventional composite resin contains larger filler particles , has the greatest strength but duller and rougher. , lincisors) Microfilled contains inorganic filler that produces a highly polished : restoration , used for anterior teeth restorations. (Ant post ) Composite contains both macrofill + microfill particles. Can polished. +. Hybrid : be and used for anterior and posterior restorations.  Flowable composite I Supplied with hybrid nanofilled with enough filler to make it wear resistant. - or Flow is key describing this - term to composite. - Material is designed to flow into conservative restorations syringe tip is added to material to be extruded into - a syringe type minute preperations. Poly merization - Resin material is changed into plastic state into hardened restoration. Light-cured - auto-cured. occurs through Composite - - Blue light Application. 1 Select shade of tooth. 2 Tooth preparation (acid etch). 3 Place required amount of material onto treated pad or light-protected well. 4. Place material in increments 5. Light cure material 6. Material is finished and polished Shade Selection colour with matching is critical when working composite resin. - If not colour matched properly this will be obvious to patient after restoration is complete. Y , shade guide for shading application = correct - Determine shade in natural light. (not under ambient lighting  Acid etch only for composite Dry cavity thoroughly - prep etch to wall for 15-30 seconds -apply enamel Treated will chalky /frosted - area appear If prep becomes contaminated with saliva , repeat for half of time. - Repeat and isolate tooth. Only 7-15 sees for second. try (Half the time) Removes saliva and creates microporisites - smear layer , Precautions avoid contact with soft tissue , if contaminated. rinse thoroughly - Highly acidic , protects the pulp -. Bonding procedures - chemically bonds composite filling material to tooth structure(adds micro mechanical retentions) -Light cured so no mixing. Precautions - Protective shield when curing binding agent to protect eye hazard to provider and patient. Light should guided properly the right surface. - be on Step 1= Primer Step 2 = Bond. Light cure 20-30 sees following manufacturer. apply bonds to etched surface tooth. Bonding agents Chemically bonds composite filling material to tooth structure, - Micro mechanical retention - Supplemental in - retention to mechanical some cases. 1 + 2 (prime + bond) - - Cannot be used interchangeably (substituted Follow manufacturers instructions - Advantages Bonds further support of tooth structure prevent breakage and to tooth damage -. , Bond is colour blended to match natural tooth. - Fix misshaped chipped or discoloration to tooth - ,. , One last 6-12 procedure - years - food Little sensitivity to not and cold amalgam filling - , common in. -Won't need of tooth structure to drill much , such as amalgam fillings. Disadvantages Composite is time than amalgam filling consuming - more. Procedure specific (etch Bond) - + High cost - Precautions of shield ensure use proper protective - Dispense material prior to use (sets once exposed to light) - Darker shades longer curing time - = For before next application. larger restorations , increments is cured Micro mechanical retention Bonding agents used to microscopically to interlock wh = enamel porosities , dentinal tubules , and other structures. Macro Mechanical retention = Undercuts made in dentin to retain non bonded amalgams and self or auto cure comp  a -microchanical mechanica Application of composite vs amalgam - Cavity preparation of composite resin is designed to hold the resin to material by micro mechanical retention. certain dental materials is not compatible with composite resin. - the will with composite resin. system - matrix vary & between applied in increments and light cured in - Glass ionomer (GC) - most versatile dental material excellent biocompatibility with oral environment. - of GIC to alter chemical for different uses adaptability abilities to them to be used in the mouth. - allow - GIC used for perm. restorations, liners , bonding agents , and cement. Primary teeth children's fillings. - > - For adults > restorations only - - minor Not for stress high - Indications Primary teeth - - Final restorations for non bearing areas Intermediate restorations - - Core material for build ups - Provisional restorations Binds chemically not - mechanically. Bonds directly enamel/dentin and metal - to , restorations - Slow fluoride release Types of GIC (crowns + veeners) Type. For 1 cementation of metal restorations and direct bonded ortho. brackets. of Type 2 Restoring erosion near gingiva. - areas Type 3-used as liner and dentin bonding agents. Reinforced GIC-Silver and Tin. For stress. high GlC- Amalgam -3 Mechanical varnish of GIC Supply Comp. micro mechanical - etch Powder and liquid treated paper pad slab. mixed manually cool glass dry = on or = Cool glass slab will extended of. working time cement Premixed paste (tubes) = auto mixes being dispensed Light while. cure and auto cure. Pre measured capsules = mechanically triturated and dispensed through a dispenser (Like amalgam capsules Precautions - avoid water contamination and contact with material when disappears setting stage - glossy appearance , has begun. band Material will adhere to material protect the matrix -.. Temporary Restorative Materials aka Intermediate filling material (irm) maintain , restore , and function , and keep pt Comfortable for limited time. ~. a Temp utilized for various dental situations ~ , restorative materials are Indications Reduce sensitivity and discomfort of tooth to determine diagnosis ~ maintain function and esthetics until placed. ~ permanent restoration is ~ protect margins of a prepared tooth until permanent casting. ~ prevent shifting of adjacent teeth caused by open or opposing space. Intermediate Restorative material (1 km) - IRM is Reinforced Zinc Oxide Eugenol composition The engeno has sedative/soothing effect the pulp. - on - Place temp crowns with Zoe. cavity (replaced with dissolves oral flora. Dissolves in oral permanent filling) in - - IRM is for short term restorations Commonly used for restorative (pain/trauma - emergencies - Last for several months. (6 months) Used for temp. restorations. - Crown Supplied powder/liquid form Mix treated paper pad/glass slab. - as. on Not and strong - Tooth whitening materials AKA Cost effective way of restoration of teeth. bleaching -. Tooth from peroxide-based whitening made ingredients - (Hydrogen peroxide) Gel in %, 16 %, 22% - comes 10 concentrations. (Higher concentration , more effective , more sensitivity) - Peroxide based work deep within enamel to remove staining. - Peroxide breaks down and enters enamel and denting bleaching discolouration. oxygen , Indications ~ Discoloration of teeth ~ Trauma Tetracycline staining ~ ~ Excessive fluoride - old restorations Consumption of staining ~ substances Aging ~ ~ Nerve degeneration Treatment options In office expensive - Fast results (High concentration) - Professionally applied - At home ~ Custom filled bleaching trays ~ vacuum formed like ortho. positioners / mouth gaurds ~ Prescribed concentration Over the counter ~ Strip/toothpaste ~ Paint on solutions Indirect Restorative Materials -aka castings ~ Restorations made outside of the dental lab technician. mouth by tooth final impression Preparing ~ restorative material in , taking , and setting place. Material (casting) is bonded cemented in place. ~ Indirect Restorative or Noble Metal Alloys ~ Gold , pallidium + Platinum Base Metals ~ low value - IROn , Zinc , TIN. Ceramic castings Made of material with clay glaze ~ a Porcelain type of ceramic in dentistry ~ Most common. Liners , Base , + Bonding Systems. (Dycall Materials used restorative and esthetic procedures for the health and ~ in well of the teeth. being Tooth depend if 1 of 5 materials in tooth. depth will protecting ~ on. Liners , varnish bonding · dentin sealer base , , , agent To make tooth less sensitive , put Zoe under filling to sedate pulp. Pulp Responses Types of Stimulus - Physical - Thermal (Hot + cold) · Electrical > Handpiece - Mechanical Trauma Occlusion - , Chemical - - Acid from dental - materials Biological - - Bacteria from Saliva. Pain sensitivity and discomfort after is placed Happens decay - , , restoration. when has progressed through enamel and into dentin. Immediate several after - or months - Give Medication for protection against pulp response. Lines deepest portion of prep - - Seals exposed surfaces of prepared tooth. Seals dental tubules - - Protects pulp tissue from physical , mechanical , Chemical , and biological. - Thin layer (0 Smm) g. Not placed in thick amounts - Stimulate Calcium Hydroxide production of dentin. - (Dycal) Protects the ~ pulp. Compatible w/ all types of restorative materials Calcium Hydroxide. (Dycal ~ available in both ight cure and to cure ~ uses and Characteristics · Protects pulp from chemical irritation its sealing ability. the by Stimulates production · and dentin. or reparative secondary pulp exposure is expected. · use when Compatible of restorative material · with all types. used under restorative material · of any type soluble · Highly Preparation mixed in circular motion until uniform Mixing time-10-15 seconds - in colour. I Setting time- 2-3 minutes in mixing pad if not light cured version. Calcium two Hydroxide comes in paste system. Dispense equal amount of and catalyst. - base Application of Calcium Hydroxide Mixed Calcium Hydroxide is placed dentin in deepest portion of the preperation. ~ on used from enamel · explorer is to remove excess material or undercuts before it dries. Cavity varnish ~ Most common brand is Copalite/Copal Varnish Conly for amalgam not compl Resin based material that seals tooth Structure interface amalgam restoration and - between · Prevents discoloration of tooth caused of free to by migration metallic ions tooth structure. Indications of Cavity varnish ~ Seals dentinal tubules ~ Reduce leakage around restorations ~ Protects tooth from highly acidic elements , such as Zinc phosphate. -should not be used with comp. resin + GIC restoration. Cavity interferes with and setting reaction. · varnish bonding Application of Cavity Varnish after liner disposable applicator always applied cotton pallet. · or of walls floor of Thin varnish the margin Cavity preperation. - coating on , , apply secondroat-2 · coats is suggested Composite goes with liner Varnish goes everywhere Liner goes on deepest portion. Dentin Sealer/Desensitizer used for comp. + GIC Comp. + GIC doesn't like Varnish Indication Treat prevent hypersensitivity ~ or ~ Seals dentinal tubules to prevent fluids from in between tooth and leaking oral and restorations causing hypersensitivity ~ Ideal for indirect restorations. Application ~ Do not allow contact with soft tissue.S. CHEMA + Glutahaldehyde) ~ all over area of exposed dentin. apply Bonding Agents Function and purpose : added to of restorative material cavity prep just before placement - Reduce microscopic dentin and restorative material - between gap. ↓ · Reduce microleakage · ReduceSensitivity of restoration · Help living tissue recover from stress application self Light cure , cure , and dual cure Complex procedure acid etch drying and light curing. ~ - , , ~ manufacturer's instructions must be followed enamel bonding ex of enamel · bonding · Sealants - occlusal surface of teeth · Bonded or tho brackets Resin bonded bridges · · Bonded veneers Dentin - Bonding placed on prepared dentin to bond Smear layer "natures bond" S - from actual solid prevents bonding agent contracting the Surface of dentin. etching Systems prep for ~ remove smear layer in bonding - Creates microporsities Supplied : Liquid/Gel interferesa GIC - Maleic acid Phosphoric acid (37-41 %) - Spill management Dispose with licensed waste disposal contractor - Do not throw in - away sewages Place - in sealed containers Dental bases Protective Base - Protects pulp from post operative sensitivity and damage. Insulating base deep preps to protect tooth from thermal shock Placed in - Sedative base Soothes pulp from or irritation of removal of damage by decay - decay (mechanical decay of Base material Types and Zinc oxide eugenol-insulating Sedative Zinc phosphate - placed over Liner Thermal. insulator but cause irritation because of phosphoric acid. Protective and insulating Zinc Polycarboxylate. Non-irritating and used for - all of indirect direct restorations. types + Glass Conomer Slow fluoride release. For deep prep teeth. + primary - application powder , liquid apply ~ , -entire pulp is covered w/base thickness 1- 2 mm  Dental Cements intermediate temp restorations ~ perm. + , ~ luting for indirect + or tho bracket/bands ~ Thermal insulator for metallic restorations periodontal packs sedation - zoe - Affecting cements Mixing time Humidity Powder to liquid ratio Temperature luting agents · Permanent · Temporary Ex. Zoe , In phosphate , Polycarboxylate + GIC-slow fluoride release. Perm. Luting cement ~ for long term cementation Inlays laminate or tho appliances · ~ crowns , veneers , , Ex resin.. Zinc phosphate , Polycarboxylate , GIC + composite Temp. cement Luting ~ To monitor tooth before perm. placement ~ Ex Zinc Oxide. engenol ~ for provisional/temp. coverage. & Zinc Oxide Eugeno ( (Zoe Type / , IRM , Temp bond - · for temp. cementation (putty long term durability · lacks and strength + Type 11 (Relyx ( Has reinforcing agents · · for restoration of cast restoration appliances perm. or Supply of 20e Liquid/powder ~ Mixed on oil resistant pad 30-60 seconds Mixing - Setting 3-5 minutes - paste -two paste system as temp cements , - dispensed in equal length on paper pad and mixed of Zinc Phosphate Types ~ Zinc Oxide + phosphoric acid acidic Highly ~ Liquid powder ~ increase -cool glass slab to setting time base perm cement or insulating ~. ~ exothermic  of Zinc Phosphate Types Type 1 (Finegrain) · permanent cementation bridges · Crowns Inlays , , onlays , luting consistency - film thin layer for castings - Type 2 (medium grain ( insulating base for deep cavity · preparations putty consistency · Cement preparation - Powder added and mixed in increments 8 figure ~ motion in mixing. spread out heat time , cooling-setting mixing - - - 15 sees Mixing increments - Mixing time- I'lz-2 mins 1 for luting -1 5 inch string.. : Zinc Polycarboxylate. (permanent ~ Properties - Viscosity Strength Bonding , , to enamel Tph acidic - lower ph. powder and liquid ~ irritating under and (luting ~ non base comp. amalgam. ~ perm. Cement for cast , metal crowns , or tho bands (putting supply ~ Limited shelf life. Thickens as water evaporates ~ mixed slab pad on glass + treated paper - Powder/liquid More powder = putty Guidelines for mixing dental cements powder toward one end of paper pad Liquid opposite end glass or. on cement removal - explorer , mouth mirror , spoon excavator fulcrum always use - clean instruments right away cement is sticky - - Articulator Replicates movement of TM) - Sandblaster-Blasts sand and air Polish. castings Dental lather Trimming casting and appliances Model trimmer Trim study models - Heat Source e- Heat waxes.  Chapter 46 agar-Gelatin type derived from seaweed. Used as a thickener. alginate Hydrocolloid material used for impressions - preliminary base-foundation or basic ingredient of a material border adaptation of margins of molding using finger pressure to contour a closer an - impression while still in the mouth. catalyst - substance that modifies or increase the rate of a chemical reaction. centric - Having an object centered. colloid - Suspension of particles in dispersion medium such as water. Two phases sol and get. digital impressions - intraoral scan of a dentition and gingiva. elastomeric - Elastic properties from rubber. hydro--water imbibition absorption of water causing an object to swell. - , occlusal registration - patients bite with wax or elastomeric material. of watering. Causes syneresis loss shrinking , - tempering- bringing a material to a desired consistency viscous flow. Viscosity physical property of fluid related to resistance to - , a > Day 4 Pg 10-17 * ↓. Dental Impressions Taken for indirect restorations , implant , denture , bleaching trays , mouth gaurd and , retainer , dental Negative impressions Positive model created - - Traditional/material based impressions Preliminary Impression of teeth and tissues and surrounding less precise Diagnostic models/casts provisional coverage - orthodontic , custom trays , , appliances stock tray plastic tray - , - Credential DA/Dentist Final impressions Impression of teeth and tissues and surrounding accurate reproductions indirect cast restorations full - , partial or dentures , and implants. Dentist/EFDA/RDA tray - Plastic tray bite - , Bite registrations Produce a reproduction of the occlusal relationship between mand. and. max teeth occluded. when month is Bite tray - Centric relation between Dentist/RDA/EFDA - arches. Bite tray Preliminary Final impressions Impression trays 7) Place impressions to oral cavity 2) Hold material close to teeth 3) Avoid removal breaking during 4) Prevent after removal warping stock trays - Metal , plastic , polystyrene. Edentulous partially edentulous - or months (without teeth) missing teeth ( some Sizes Perforated trays - Holes in tray Quadrant-half of arch (mechanical lock) Section-anterior portion Smooth trays - no mechanical lock Full arch-covers entire arch adhesive spray 15 mins before impr) -. ! Rim lock-Rounded rim on border to hold impression material Selected by tray measuring the patients mouth - in Comfortable for patient - extend facial surface of teeth slightly above - 2-3 mm beyond 3rd molar , retromolar, tuberosity of arch Deep allow of material and incisal occlusal edge of - to 2-3 between mm tray or teeth. Must cover entire arch -  Adaptation If for patients with palate , necessary , unusually high softened wax can be added (beading wax) to impression tray Custom trays Designed to fit month of a specific patient. Types of elastomeric impression material. 1 Polysulfide (poor dimensional stability (. 2 Condensation Silicones (average dimensional stability). 3 Polyether very good I dimensional stability ( 4. Polysiloxane (excellent dimensional stability) Laka lused for accuracy) ? Polysiloxane has low tear resistance making handling , easier. supplied in cartridges and putty consistency. Single impressions - Multi impressions - Custom tray procedural steps 1. Preparing the model al fill the under cuts with block out material on diagnostic model. b) Outline tray w/ pencil c) Place baseplate wax spacer , trim , and adapt wax to cast