INBDE Bootcamp High-Yield Operative Dentistry PDF

INBDE Bootcamp High-Yield Operative Dentistry | Bootcamp.com Composition of teeth Mineral Description...

INBDE Bootcamp High-Yield Operative Dentistry | Bootcamp.com Composition of teeth Mineral Description Apatite Inorganic calcium phosphate mineral group, main constituent of teeth Carbonate-substituted apatite, hexagonal in structure Hydroxyapatite Main component of enamel and dentin Makes enamel rods, which are organized in a crystal lattice structure ○ Have a head and tail – tail has a higher component of organic material and is more susceptible to decay Fluorapatite Fluoride-substituted apatite, more resistant to demineralization from acid challenge Stephan curve Stephan curve - shows the normal curve during the introduction of acid to the oral cavity Critical pH of dentin and cementum: 6.2-6.7 Critical pH of enamel: 5.5 Critical pH of fluorapatite: 4.5 When salivary pH is lower than the critical pH, demineralization will occur Progression of a cavity occurs due to the process of demineralization: Hydroxyapatite ⇌ Ca2+ + PO43- + H+ ⇌ Ca2+ + H3PO4 When sugar is introduced the equation is pulled to the right, the direction of demineralization, by LeChatelier’s principle Saliva contains bicarbonate (HCO3-) which helps buffer the acid and shifts the equation to the left, the direction of remineralization Caries Progression of lesions E0: No caries or E1: Caries in outer half of the E2: Caries in inner half of the D1: Caries into the D2: Caries into the middle D3: Caries into the inner radiolucency enamel enamel but not the dentin first third of the dentin third of the dentin third of the dentin © Bootcamp.com  INBDE Bootcamp High-Yield Operative Dentistry | Bootcamp.com Smooth surface V-shaped May have a double V, one in the enamel and one in the dentin Lesion characteristics Pit and fissure Inverted V shape Look for change in translucency of the enamel Root surface Rapidly progressing Due to high critical pH of cementum Terminology Infected dentin Wet, soft, mushy dentin that has been infiltrated by Simple Caries covers one surface of tooth (ex. O) bacteria Must be excavated during caries removal Affected dentin Dentin that is demineralized but contains no bacteria Compound Caries covers two surfaces of tooth (ex. MO, DO) Affected dentin can be left during caries removal Incipient lesion Appears opaque when air dried, disappears when wet Complex Caries covers three or more surfaces of tooth (ex. MOD, Can remineralize DOL) Enamel is not intact, typically caries have progressed Cavitated lesion to dentin Primary Original lesion Irreversible Acute/rampant caries Light-colored, soft, highly infectious Secondary/recurrent Found at the junction of the tooth and previous restoration Chronic caries Dentin that is almost remineralized, discolored, and Residual Caries that remain after completed cavity preparation fairly hard Arrested caries Brown/black, not progressing Contains sclerotic dentin formed by tooth to protect pulp Erosion Attrition Abrasion Abfraction Chemical loss of tooth Pathologic, mechanical structure without bacterial Heavy occlusal forces tooth wear Loss of tooth structure in involvement against natural teeth Ex. toothbrush trauma, cervical areas due to tooth Ex. acidic drinks, acid reflux Ex. bruxism ceramic crowns against flexure natural teeth © Bootcamp.com  INBDE Bootcamp High-Yield Operative Dentistry | Bootcamp.com Cavity preparation Cavosurface margin: Where preparation meets natural tooth External walls: Walls of preparation that touch cavosurface margin (ex. buccal, lingual, mesial, distal, gingival) Internal walls: Walls that touch external walls (ex. pulpal floor, axial wall) Line angle: Junction between two walls Point angle: Junction between three walls GV Black classification Class I Class II Class III Pits and fissures Interproximal posterior Interproximal anterior with no incisal edge Class IV Class V Class VI Interproximal anterior with incisal edge Buccal or lingual surface, cervical 1/3 Cusp tip or incisal edge only Tooth preparation 1. Outline form Defined by the extent of caries Must remove friable and unsupported enamel 2. Primary resistance form Preparation must withstand masticatory pressure Pulpal floor should be flat, internal line angles should be rounded Initial 3. Primary retention form Prevents dislodgement of restorative material (convergent walls and dovetail) Composite relies more on bond strength for retention 4. Convenience form Allows the operator to visualize and access the preparation and restoration 5. Remaining caries removal Remove all infected dentin or faulty restorative material Water usage is important to avoid heat damage to pulp 6. Pulp protection ≥2 mm from dentin to pulp: desensitizer (seals dentinal tubules) Deep or approximating pulp: indirect pulp cap + liner + base Final ○ Liner: Calcium hydroxide, insulates and protects the pulp. Stimulates © Bootcamp.com  INBDE Bootcamp High-Yield Operative Dentistry | Bootcamp.com odontoblasts to form tertiary dentinal bridges. ○ Base: RMGI used over liner for protection < 1 mm pulp exposure/asymptomatic: direct pulp cap + liner + base > 1 mm pulp exposure/symptomatic: root canal therapy 7. Secondary resistance and retention Grooves, beveled enamel margin (composite), pins and slots (amalgam) 8. Finishing external walls Ensure preparation is smooth and clean Moisture control is essential during tooth preparation and restoration. Teeth can be isolated with a dry angle, cotton roll, rubber dam, or high suction evacuator. Additionally, a rubber dam provides protection from aspirating dental materials and from instrument laceration. Amalgam Material can conduct heat, so patients may experience post-operative sensitivity to heat and cold Galvanism: electric shock-like sensation from contact between amalgam and another metal Features of amalgam tooth preparation Bur Retention Resistance for tooth Resistance for amalgam Use carbide bur for smooth walls Create occlusal convergence 90° cavosurface margin 90° amalgam margins 245 carbide creates retention form because Utilize grooves, slots, and pins Maintain cusps and ridges 1.5 mm–2 mm depth of amalgam to prevent of its pear shape Remove unsupported enamel material fracture Flat pulpal floor, rounded line angles Handling Trituration Mercury toxicity Mixes amalgam so elemental mercury reacts with alloy powder Type of mercury in amalgam is elemental mercury Normal mix: putty-like, shiny, and smooth Inhalation is the greatest risk factor Under-triturated: dry, dull, crumbly, and sets quickly Important to work with good ventilation Over-triturated: warm, wet, soft, and is difficult to condense Mercury is most likely element in amalgam to cause an allergic reaction Composite resin Isolation from water and saliva is critical for bond success Enamel bonding is more predictable than dentin bonding because dentin has more organic matter and water Composite restorations can fail due to inadequate bonding and secondary caries A bevel on the preparation is indicated for class IV and V restorations to improve shade match and increase bond surface area © Bootcamp.com  INBDE Bootcamp High-Yield Operative Dentistry | Bootcamp.com Etch, prime, and bond Acid etch Prime Bond Acid etching provides micromechanical retention for composite Primer helps promote penetration of composite material into The bonding agent contains monomers that are restorations by removing the smear layer, creating surface dentin to increase bond strength. It infiltrates enamel prisms hydrophilic and hydrophobic that will bond through MMA irregularities and opening dentinal tubules. and dentinal tubules and prevents collagen collapse. bonds. Composition: 37% phosphoric acid Composition: Resin monomer wetting agent (HEMA) Composition: Bis-GMA (bisphenol A glycidyl Etch→rinse→lightly dry and solvent (acetone, EtOH, and/or H2O) methacrylate) ○ Do not overdry and desiccate the enamel Can cause contact dermatitis, a type IV The key to adhesive dentistry is the Etched enamel will have a frosty white appearance hypersensitivity reaction micromechanical bond! Types of composite Composition Resin matrix: Bis-GMA Types of filler Filler particles: Silica ○ Powdered ceramic glass, radiopaque Macrofill 80% filler and large filler size Amount of fillers affects properties Lowest wear resistance, highest strength under occlusal Coupling agent: Silane loading ○ Promotes adhesion between resin and fillers Hybrid 80% filler, small filler size Composite has a lower compressive strength than amalgam Smooth surface because of small filler size and can fracture more easily Less wear resistance than micro/nanofill Curing method Microfill 40% filler, small filler size Self–cure Two-paste system Benzoyl peroxide is the initiator Tertiary amine is the activator Nanofill Highly filled, smallest filler particles Highest wear resistance Light–cure Single paste system Flowable Lower filler content Camphorquinone is the photoinitiator Lower wear resistance Darker shades=longer curing times Dual–cure Good for large build-ups where light cannot fully Packable Large fill, giving higher strength penetrate More filler, less water absorption Zinc oxide eugenol is a temporary material that can inhibit the polymerization of composite (self, light, and dual cure). Remove all ZOE before placing resin composite. © Bootcamp.com  INBDE Bootcamp High-Yield Operative Dentistry | Bootcamp.com Glass Ionomer Restoration of anterior teeth (class III and class V sites), restoration of root caries lesions Uses Luting cements Intermediate restorations, liners and bases Advantages Disadvantages Additional information Releases fluoride to tooth structure Low pH can be irritating to pulp Resin modified glass ionomer (RMGI) is a Does not require perfect moisture control Not as strong as composite resin hybrid between resin and GI. It contains Creates chemical bond to tooth structure If the glass ionomer mixture is desiccated, cracks beneficial properties of both materials or craze lines can develop in the restoration Caries risk American Dental Association’s Caries Risk Assessment (Age >6): Low risk = only conditions in “low-risk” column present Moderate risk = only conditions in “low risk” and/or “moderate risk” columns presents High risk = one or more conditions in the “high risk”column present Contributing conditions Low risk Moderate risk High risk Fluoride exposure Yes No Sugary food or drinks Primarily at mealtimes Frequent or between meals Regular dental care Yes No Caries experience of mother, caregiver, and/or other siblings None in the last 24 months Caries in the last 7-23 months Caries in the last 6 months Special health care needs No Yes (over age 14) Yes (ages 6-14) Chemo/radiation therapy No Yes Eating disorders, medications that reduce No Yes salivary flow, or drug/alcohol abuse © Bootcamp.com  INBDE Bootcamp High-Yield Operative Dentistry | Bootcamp.com Cavitated or non-cavitated carious lesions or restorations (past 36 months) None 1 or 2 3 or more Teeth missing due to caries (past 36 months) No Yes Visible plaque No Yes Tooth morphology that compromises hygiene Interproximal restorations Exposed root surfaces Restorations with overhangs, open margins, or open contacts Oral appliances Xerostomia No Yes Ellis classification of tooth fracture © Bootcamp.com  INBDE Bootcamp High-Yield Operative Dentistry | Bootcamp.com Veneers and onlays Veneer indications Veneer contraindications Veneer preparation Peg laterals, diastemas between teeth, staining (e.g. Hypocalcified enamel: will not allow adequate bond Chamfer margin, shoulder/buttjoint incisal tetracycline, fluorosis, amelogenesis imperfecta) strength preparation Bruxism An onlay is an indirect dental restoration that is fabricated by the laboratory and cemented in the mouth. Onlay preparation 1. Walls of onlay preparation should be divergent so the restoration can be fully seated 2. Internal line angles should be rounded 3. Create a collar: a beveled shoulder margin around the capped cusp for bracing 1. Apply hydrofluoric acid to the veneer for cleaning and etching, then rinse and dry the veneer. Cementation protocol 2. Apply silane (containing the primer) to the etched veneer surface, then air-dry. 3. Etch and bond the tooth according to manufacturer instructions 4. Cement the veneer or onlay with resin cement © Bootcamp.com