Questions and Answers
Class II cavities originate on the _______ surfaces of premolars and molars.
proximal
What are different types of Class II cavity preparations?
slot, conventional: MO/DO, MOD, complex
What are the advantages of a slot prep?
minimally invasive, resistance
What are the different slot prep variations?
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It is okay to leave non-carious grooves or pits ______!
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What is the occlusal outline form for amalgam Class II cavity preparations?
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Proximal outline form: Break contact buccal, lingual, and gingival walls approximately _____ mm.
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Buccal and lingual walls should be parallel or slightly ______.
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Resistance form prevents dislodgment or fracture of the restoration or fracture of the remaining tooth structure by oblique or ______ forces.
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How does retention form prevent dislodgement of the restoration along the path of insertion?
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What is the axial extension of the gingival box for premolars and molars?
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How should the gingival floor be established?
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Why must enamel spurs be removed?
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Cave surface margin needs to be at ___ degrees to avoid undercutting enamel rods.
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What are retention grooves?
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What might recurrent decay around amalgam restorations be indicative of?
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Why do we burnish the matrix at the contact area?
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What is considered clinically acceptable for the axial wall?
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What is the clinically acceptable width for gingival seat M/D for molars?
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What is important for clinically acceptable proximal box and cavosurface?
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What is the requirement for clinically acceptable retention?
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What are clinical requirements for proximal and gingival preparation?
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Why do we pre-wedge?
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Study Notes
Class II Slot Preparation Key Concepts
- Class II cavities are found on the proximal surfaces of premolars and molars.
- Types of Class II cavity preparations include slot, conventional (MO/DO, MOD), and complex.
Advantages of Slot Preparation
- Minimally invasive approach reduces tooth structure removal.
- Increased resistance to fracture; larger isthmus correlates with a higher fracture risk.
Slot Preparation Variations
- Variants include 1 contact, M/D, and modified 1 contact.
Non-carious Structures
- Non-carious grooves or pits can be left unrestored.
Occlusal Outline Form for Amalgam Cavity Preparations
- Focus on carious grooves when fissures are sealable; avoid sharp corners.
Proximal Outline Form Specifications
- Break contact on buccal, lingual, and gingival walls by approximately 0.5 mm.
Wall Orientation
- Buccal and lingual walls must be parallel or slightly convergent.
Resistance Form Characteristics
- Prevent displacement or fracture from oblique or compressive forces with flat floors and rounded line angles.
Retention Form Requirements
- Prevent dislodgment of restoration along the insertion path through cavity depth, box form convergence, and effective wall relationships.
Axial Extension Guidelines
- Premolars: 1 mm, Molars: 1.2-1.5 mm for axial extension of the gingival box.
Establishing Gingival Floor
- Place gingival floor just below caries, ensuring 0.5 mm separation with the adjacent tooth using an explorer tip.
Importance of Removing Enamel Spurs
- Necessary for achieving a 90-degree cavosurface margin for amalgam restorations.
Cavosurface Margin Angle
- Must be at a 90-degree angle to prevent undercutting of enamel rods.
Retention Groove Specifications
- Extend from the axial wall to the facial and lingual axio line angles, avoiding pulp by cutting on the upstroke.
Recurrent Decay Indications
- Presence of recurrent decay around amalgam restorations may signify inadequate retention form.
Matrix Contouring Technique
- Burnishing the matrix band at the contact area creates a convex contour, assisting in achieving a larger contact area.
Acceptable Axial Wall Profile
- The axial wall should be convex and follow the contours of the facial and lingual surfaces.
Acceptable Gingival Seat Width
- Molar: 1.2-1.5 mm; Premolar: 1.0 mm for gingival seat width.
Proximal Box and Cavosurface Requirements
- Slight convergence (6 degrees) of occlusal and proximal walls, occlusal walls must form a 90-degree angle to cavosurface margins, and no unsupported enamel should remain.
Acceptable Retention Groove Placement
- Groove depths of 0.25 mm extending from the base of the gingival floor to the level of the pulpal floor.
Contact Break Specifications
- Facial and lingual contacts (M or D) should be broken by 0.3-0.5 mm, with the depth of preparation determined by gingival contact break distance, and axial wall height should exceed 1.5 mm.
Purpose of Pre-wedging
- Protects gingival tissue and adjacent teeth, creates room for occlusal embrasure, and facilitates matrix insertion, while preserving tooth strength with a smaller outline form.
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Description
Test your knowledge about Class II cavity preparations with this informative quiz. Covering definitions, advantages, and types of cavity preps, it's perfect for dental students and professionals alike. Prepare effectively for your examinations with these flashcards.