Operative Dentistry II Final Exam Review

Three Surface Class II Preps

• Composite resins have different opacities:
  • Dentin: high opacity
  • Body: opacity between dentin and enamel
  • Enamel: low opacity
  • Incisal: translucent
• Shade selection:
  • Timing: before isolation
  • Location: middle third of the tooth
• Instruments for composite resin placement:
  • Plastic instruments
  • Metal instruments
  • Lightly dampened alcohol gauze
  • Adhesive with no primer
  • Finishing and polishing burs

Advantages and Disadvantages of Resin as a Posterior Restorative Material

• Advantages:
  • Esthetics
  • Conservation of tooth structure
  • Adhesion to tooth structure
  • Low thermal conductivity
  • Elimination of galvanic currents
• Disadvantages:
  • Polymerization shrinkage (C-Factor)
  • Secondary carious lesions
  • Postoperative sensitivity
  • Decreased wear resistance
  • Bonding technique sensitivity

Ideal Radiograph and Cavity Preparation

• Ideal radiograph for Class II caries detection:
  • Bitewing radiograph
• Class II cavity preparation general elements:
  • Preservation of tooth structure
  • Access for adequate caries removal
  • Round internal line angles
  • Clear cavosurface without beveling

Composite Restorations

• Best isolation for posterior resins:
  • Rubber dam
• Matrix system:
  • Sectional matrix is the first choice when possible
  • Seal gingival margin
  • Wedge from lingual, open embrasure
  • MOD composite technique
• Dental bonding components:
  • Conditioner (acid: 35-42% phosphoric acid)
  • Primer (hydrophilic monomers when bonding dentin)
  • Adhesive (low viscosity filled or unfilled resin)
• Dental bond in CU clinics:
  • Opti Bond FL (three-step etch, rinse, and bonding system)
• Dental bonding procedures:
  • Acid etch on enamel first and then dentin (no more than 15 seconds)
  • Rinse for 15 seconds, removing excess moisture from the operating field
  • Apply primer with a micro brush for 30 seconds
  • Air dry primer from a distance, do not desiccate
  • Apply an even coat of adhesive, remove excess with a micro brush, and use an air syringe to disperse
  • Light cure for 20 seconds
  • Apply resin
  • DIFFERENCE FOR ENAMEL: NO PRIMING
• Incremental placement:
  • 1st increment always at the gingival floor
  • Equals the area of highest contamination potential
• Flowable resin characteristics:
  • Micro hybrids and nano fills
  • 0.5 mm or less
  • Very careful with voids (as viscosity goes down, the risk of porosities increases)
  • Higher polymerization shrinkage
• Plowing flowable technique:
  • Pushing flowable resin to the sides to seal the margins

Complex Composite Restorations

• Foundation definition:
  • Initial restoration of a severely involved tooth
  • Serving in place of tooth structure to provide retention and resistance forms during the development of the final indirect restoration
  • Type of restoration: Direct complex restoration
• MODL preparation:
  • MOD preparation first
  • DL depth cut parallel to cusp incline (1.5-2 mm deep)
  • Several depth cuts
  • Join the depth cuts
  • Internal line angles must be round
  • Clear cavosurface without beveling
• MODL foundation composite shade choice:
  • Lighter composite = better depth of cure and better visualization
• Tofflemire matrix for composites:
  • Must be ultra-thin matrix, burnished between increments in order to ensure contact
• Composite restorative steps:
  • Dental bonding
  • First increment placed on the gingival floor (1mm thick max, light shade)
  • All other increments no more than 2 mm
• Finishing:
  • #12 scalpel clean excess at the gingival margin
  • Finishing burs
  • Shofu snap disks/Shofu Strips
  • Rinse between grits
  • Dicomp polishing points
  • Green – slow with water
  • Grey – fast and dry
• Bulk fill composites:
  • Flowable base bulk-fill composites
  • Majority of bulk fills require a conventional composite as the occlusal increment
  • Full bulk fill composites (Filtek One Bulk Fill)
  • Replace both dentin and enamel
• Core composite materials at CU:
  • Filtek Supreme Ultra
  • Nanofill/Nanohybrid
  • Radiopaque
  • High strength
  • Choose opaque shade
  • Incremental technique
  • Cosmecore
  • Dual-cure composite core build-up material
  • Radiopaque
  • High strength and depth of cure
  • 3 shades
  • Bulk fill – cures 7mm depth

Three Surface Class II Amalgam Prep/Restoration

• Situation where amalgam might be better:
  • Very deep Class II lesions
  • Ability to condense amalgam to seal amalgam
  • Fewer concerns with depth of cure
• Planes of maxillary molars:
  • Two planes: Distal is tilted in comparison to the mesial portion
  • Significance: Need to tilt the bur more towards the distal to prevent undermining of adjacent ridges
• Initial clinical procedures:
  • Anesthesia
  • Occlusal relationship
  • Isolation
• Preparation instruments:
  • 329, 330, 245 for initial access and prep
  • Round 1, 2, 3, 8 for caries removal (Largest that fits)
  • Straight fissure 56, 57 on slow speed to flatten pulpal floor and gingival wall only
  • Hatchets and margin trimmers
• Pre-wedging purpose:
  • Helps to protect adjacent tooth
  • Creates tighter contact
  • Protects rubber dam
  • Prevents gingival overextension
  • NOTE: Remove to evaluate if proximal contact is broken
• Preparation elements:
  • Establish outline
  • Cut around triangular ridge
  • Lean more towards oblique ridge vs. distal incline
  • Pulpal floor is tilted towards the lingual surface
  • Provides strength for amalgam
  • Lingual extension; prep vertical with long axis or perpendicular
  • Create access to and remove faulty structure
  • Create resistance, convenience, and retention forms
  • Pulpal floor smooth and uniform depth parallel with occlusal surface
  • Gingival wall smooth, leveled, and parallel to occlusal
  • Pulpal floor depth into dentin in all areas minimum of 1.5 mm
  • Internal line angles well-defined, slightly rounded
  • Axiopulpal line angle rounded/beveled
  • Undermined enamel included in prep
• Restorative technique:
  • Assessment of prepared tooth
  • Isolation maintained
  • Cleanliness and dryness of prepared tooth
  • Pretest condensers fit all areas of the preparation
  • Desensitizer placement
  • Pulp protection
  • Prepare instruments
  • Matrix placement
  • Select amalgam
  • Trituration
  • Insertion
  • Condensation
  • Pre-carve burnishing
  • Carving
  • Post-carve burnishing
  • Evaluation of occlusal

Foundations Part I

• Complex amalgam restoration:
  • Amalgam restoration that replaces one or more cusps
• Essential elements of a foundation/buildup restoration:
  • Caries removed
  • Pulp status determined
  • Adequate retention established
  • No excess restorative material beyond tooth margins
  • Proximal contact established
  • Occlusion not high
  • Restoration comfortable to the patient
• MOD to MODL transition:
  • Cusp reduction = 1.5-2 mm
  • Level pulpal floor up to lingual groove
  • Gingival floor 1.25-1.5 mm to axial wall
  • Cove 1.75-2 mm from cavosurface
  • Axiopulpal line angle beveled
  • DL wall flat
• Amalgapin placement:
  • Pilot hole – ¼ round bur
  • Place w/ 330 bur
  • 1.5-2 mm deep
  • At least 1 mm from the margin
  • Keeps margin from fracturing
  • Bevel entrance to amalgapin channel
  • 2 or 4 round bur on slow speed
• Retention grooves:
  • Distoaxial and buccoaxial line angles
  • Use ¼ round bur
  • Only the height of the axial wall
• Placement of amalgam for restoration:
  • Begin at amalgapin channel
  • Second at retention grooves
  • Fill mesiolingual box to pulpal floor

Foundations II

• Success of complex amalgam restorations:
  • Long-lasting (50% at 11.5 years, as high as 73% at 15 years)
• Factors for consideration before complex

Review of Three Surface Class II Preps, including composite resin opacities, shade selection, and instrument usage for placement and finishing.