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64 Cards in this Set
- Front
- Back
Class II caries: Anatomically the caries initiates in the...
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enamel apical to the proximal contact.
It extends as a cone to the DEJ; commonly described as two cones (or triangles) tip to base |
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Black’s Principles of Cavity Preparation
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1. Outline form
2. Retention form 3. Resistance form 4. Convenience form 5. Removal of carious dentin 6. Finishing of the walls 7. Toilet of the cavity |
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In a Class II prep, the pulpal and gingival walls are ________ to the long axis of the tooth.
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perpendicular
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Axial wall must be at least __ mm for premolars and __ mm for molars.
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1.2
1.5 |
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True/False?
For a class II prep., occlusal and proximal boxes must have independent retention |
True
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For a Class II prep: the “reverse, or “S” shaped”, curve” on the buccal serves what purposes?
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1. It preserves the mesiobuccal cusp ridge
2. Extends the wall into the buccal embrasure space 3. Leaves the enamel wall parallel to the enamel rods |
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the enamel rods on the gingival wall are inclined...
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gingivally.
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The ideal gingival extension for a proximal box is how far below the contact area?
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0.5mm
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What Classes of Cavity Preparations Need Matrices?
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ALL CLASSES
Class I- e.g., OB or OL preparation Class II- any proximal wall Class III- any proximal wall Class IV- proximal wall Class V- when preparation extends past line angles into proximal area Class IV- preparation extends including facial or lingual |
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Function of wedges during tooth preparation
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Protects adjacent tooth during preparation from being hit by bur
Protects interseptal dental dam from tearing Protects dental papilla from laceration |
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Wedges are usually placed from...
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lingual to fill the larger gingival embrasure
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Thickness of Tofflemire Matrix bands
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Regular = 0.002” (0.05 mm)
Thin = 0.0015” (0.038 mm) Extra thin = 0.001” (0.025 mm) usually used for composite restorations |
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Matrix is placed so that __ mm extends apical to gingival margin, __ mm extends occlusal to marginal ridge
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1; 2
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Mylar matrices are used only for...
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composite resin materials
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Classes of amalgams that always need matrices
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Class II
Class III Class IV |
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Root caries are typically found on what surfaces?
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facial and lingual
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pH needed for demineralization of root surface
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pH 6.2-6.7
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The population typically affected
by root caries |
Elderly patients
Patients with poor oral hygiene Patients with reduced salivary flow |
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The prevalence of root caries in the elderly population
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65-74 years: 47%
>75 years: 55% |
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The prevalence of gingival recession of 1 mm or more in patients 65 or older
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86.5 %
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Xerostomia
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Oral dryness and reduced salivary flow
Salivary flow will be reduced by 50% before the patient becomes noticeably symptomatic less minerals and fluoride to remineralize the hard tissue There is less ability to clear debris off the teeth and thus there is bacterial overgrowth |
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Minimal depth of a class V preparation
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1 mm
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Class V prep: mesial and distal should be...
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divergent
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Glass Ionomer Cements
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Less esthetic than composite
Has a chemical bound to the tooth structure Will adhere in conditions that are not completely dry Releases Fluoride Some are self curing agents |
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Compomers
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Composite and Glass ionomers
Superior to Glass ionomers in tensile strength, flexural strength and wear resistance They are bonded to teeth like composites, therefore the area must be dry There is less Fluoride release than with RM-GIC More esthetic than glass ionomers, but less than composites |
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Diagnosis Frequently Associated with Xerostomia
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Medication side effects
Autoimmune Disorders Parkinson’s Disease Psychological Disorders Radiation of Salivary Glands Diabetes Sjögren’s Syndrome Dehydration |
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Technology for enhanced caries detection
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Fiber optic transillumination
Magnification Digital radiographic assessment Light emitting caries detection devices |
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Sensitivity
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The ability to detect disease when it is truly present.
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longevity of posterior composite and amalgam restorations
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Composite resin :
91.7% at 5 years 82.2% at 10 years Amalgam: 89.6% at 5 years 79.2% at 10 years |
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What is a clinical defect requiring restoration replacement?
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Restorative material partially/completely lost (fracture of restoration)
Fracture of surrounding tooth structure Recurrent caries at a margin Poor esthetics Loss of occlusal function |
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What does “conservative dentistry” mean?
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Minimize restoration failure “repeat restorative cycle”
Retention by adhesion and/or mechanical means “Lesion-focused” preparation designs |
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Conservative alternatives to Class I preparation:
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Fissure sealant
Sealant with Fissurotomy/Fissuroplasty Preventive Resin Restoration |
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Disadvantages of Preventive Resin Restoration
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Same concerns as sealants- loss rate of 5-10% per year
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Laser Cavity Preparation
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• Advantages:
– No anesthesia usually required – Absence of vibration and sound of air turbine – Laser micro-etches dentin and enamel improving micro-mechanical retention • Disadvantages: – Lack of tactile sense when cutting – Requires open cavitated lesions for maximum efficiency – Restricted to adhesive materials due to the inability to prepare fine retentive features such as slots, grooves – Cost of initial purchase |
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accessory retention for amalgam restorations
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pins (placed into the dentin)
posts (within root canals after endodontic treatment) slots (within tooth) channels (within tooth) grooves (placed within cavity walls) |
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True/False?
amalgam is reinforced by pins |
False
Pins only RETAIN the amalgam |
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Pin must be in dentin
Surrounded by at least __ mm of dentin |
0.5
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If pin drill breaks in channel...
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Leave the drill bit broken in channel.
Find a new site to place a new channel approximately 0.5-1 mm away from where the pin drill broke. |
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Copper tube circumferential matrix (no retainer)
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Sometimes only choice for matrix when many walls of tooth are missing
Difficult to fit and stabilize Difficult to attain proximal contact due to the thickness of the band |
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Crown preparations must have a minimum of __ mm of occlusal clearance.
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1.5
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For threaded pins: maximum retention is obtained when the pin extends
__ mm into dentin and __ mm into the amalgam. |
2; 2
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Retentiveness of pins:
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Self-threading pins are the most retentive.
Friction lock are intermediate Cemented pins the least retentive. |
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Pros/Cons of pins for retaining amalgam
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Advantages. Provide resistance to displacement by lateral (non-axial) forces. Axial forces are parallel to the long axis of the tooth.
Disadvantages: Pins are prone to create microfractures in dentin. The larger the pin the greater the likelihood that microfractures will occur. |
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deep cavity depth
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depth of preparation with less than 1.0 mm of remaining dentin over pulp
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pulpal pain due to stimuli
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- not an inflammatory response
- likely due to the hydrodynamic theory - stimulus causes rapid fluid flow through tubules, nerve endings deformed- interpreted as pain - gap at tooth-restorative interface: the restoration is not well sealed |
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base thickness to prevent thermal transfer should be no thicker than __ mm (thicker bases may weaken restoration)
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0.5-0.75
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cavity sealers:
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protective coating on the cavity walls creating a barrier to leakage
- varnish (Barrier) - resin bonding systems (Scotchbond MP and OptiBond Solo) |
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cavity liners:
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cement or resin coating of minimal thickness (less than 0.5mm) placed as a barrier to bacterial or to provide a therapeutic effect (pulpal sedative or antimicrobial effect). Applied to cavity walls adjacent to pulp.
- Calcium hydoxide = Dycal - glass ionomer = VitreBond |
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cavity bases:
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placed to replace missing dentin, placed in thickness of 0.5 - 1 mm; used to block out undercuts in cavity preparations for indirect restorations
glass ionomers = VitreBond, Fuji IX |
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calcium hydroxide (Dycal)
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- Cavity liner
- Ca(OH) used to assist in formation of reparative dentin by its antibacterial effect - best used for direct pulp cap - use only small amount |
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glass ionomer (Vitrebond)
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- cavity liner
- chemical bond - fluoride release - chemically compatible with composite resins - seals dentin - generally not used for pulpal protection - primary use in the past as dentin replacement to decrease bulk of restorative material - primary use to block out undercuts in cavity preparations for indirect restorations (crowns, inlays, onlays) |
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material of choice for cavity bases
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glass ionomer (Vitrebond)
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liners should be applied with a minimal thickness of less than __ mm
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0.5
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calcium hydroxide (Dycal) should be placed only...
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where needed adjacent to pulp
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Base/Liner recommendations for amalgam/composite:
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1. Shallow cavity: Sealer -> Amalgam/composite
2. Moderate cavity: Glass ionomer -> sealer -> amalgam/composite 3. Deep cavity: calcium hydroxide -> glass ionomer -> sealer -> amalgam/composite |
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materials for use with amalgam
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1. cavity sealer
- varnish (Barrier) - resin adhesive (ScotchBond MP) 2. cavity liner - calcium hydroxide (Dycal) - resin modified glass ionomer (Vitrebond) 3. cavity base - resin modified glass ionomer (Vitrebond, Fuji II LC) |
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materials for use with composite resin
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1. cavity sealer
- resin adhesive (ScotchBond MP) 2. cavity liner - calcium hydroxide (Dycal) - resin modified glass ionomer (Vitrebond) 3. cavity base - resin modified glass ionomer (Vitrebond, Fuji II LC) |
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Varnish is only used for _______ restorations
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amalgam
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dispensing and application of sealer (Scotchbond MP) for use with amalgam
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kit contains components for amalgam sealing; used as a dual cure system
preparations with the need for additional retention beyond preparation form 1. Etch for 15 seconds 2. Activator mixed with primer, apply to etched preparation for 15 seconds and dry for 5 seconds 3. One drop adhesive and catalyst. Mix together, apply to preparation; place amalgam. |
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Purpose of adhesive
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- Seal tooth/restorative interface
- Decrease leakage at tooth/restorative interface - Enhance restoration retention by mechanical locking of adhesive to roughened surface |
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Materials for adhesive procedures
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- Multibottle: ScotchBond MP
- Single bottle: Optibond Solo Plus |
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smear layer
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- Layer on tooth surfaces created by rotary cutting instruments
- Made of loosely bound debris, collagen, and hydroxapatite crystals |
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Clinical considerations for indirect pulp capping
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- Tooth must be vital with no history of spontaneous pain
- Pain elicited from cold test or EPT should not linger - Restoration must seal tooth from bacteria - Periapical radiograph demonstrates no periapical pathology - Tooth will not have casting as definitive restoration |
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Clinical considerations for direct pulp capping
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- Pulp tissue minimally exposed (usually less than 1 mm in diameter)
- Tooth must be vital with no history of spontaneous pain - Pain elicited from cold test or EPT should not linger - Restoration must seal tooth from bacteria - Periapical radiograph demonstrates no periapical pathology - Tooth will not have casting as definitive restoration; Critical to success with direct pulp capping - Control bleeding with damp cotton pellet - Don’t use explorer tip to verify exposure |