Questions and Answers
What are the steps in the GV Black Cavity Preparation approach? (Select all that apply)
When is the reverse curve more exaggerated?
When the contact is further away from the central groove.
How deep should the pulpal floor be in a Class II preparation?
0.5 mm into dentin.
The bucco-occlusal and linguo-occlusal wall are ______ and make a _____ angle with the pulpal floor.
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What does the extent of the proximal external outline depend on?
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What is the shape of the proximal external outline?
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Why is the proximal external outline a triangle?
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What is the mandibular bucco-proximal wall angle with gingival floor?
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What is the mandibular linguo-proximal wall angle with gingival floor?
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What is the maxillary bucco-proximal wall angle with gingival floor?
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What is the maxillary linguo-proximal wall angle with gingival floor?
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What shape should the axial wall be?
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Bucco and linguo-proximal wall direction (M/D) should make a _____ angle to the tangent of the proximal surface.
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What is flare?
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What is wrong with excess flare?
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What is wrong with lack of flare?
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What shape should the gingival floor have?
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Why should the gingival floor have a C-shape?
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What determines the width of the gingival floor?
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What gives the occlusal segment retention?
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What gives the proximal segment retention?
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Class II cavity preparations can be performed on which teeth? (Select all that apply)
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What hand instruments do you need for a Class II preparation?
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Why use a wedge?
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What are three uses for the medial GMT?
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What are three uses of the distal GMT?
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What are three burs used in a Class II cavity preparation?
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How are Class II carious lesions diagnosed?
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On a radiograph, how can you tell the lesion has penetrated the DEJ?
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What determines the occlusal external outline of the proximal box?
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A minimum of ______ of separation should be allowed between the gingival cavo surface and proximal surface of the adjacent tooth.
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Why is the proximal depth at the level of the pulp-axial line angle greater than at the gingival floor area?
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Where does the proximal contact point lie on maxillary teeth?
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What two things does the reverse curve allow?
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What are four examination instruments?
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Where is retention in the proximal box placed?
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What does proximal segment retention consist of?
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Study Notes
Class II Cavity Preparation Overview
- GV Black's approach includes outlining form, resistance and retention form, convenience form, removal of carious lesions, finishing enamel wall, and cleansing the preparation.
- The reverse curve is more exaggerated when the contact point is further away from the central groove.
- The pulpal floor depth in a Class II preparation should be 0.5mm into dentin.
Wall Angles and Geometry
- The bucco-occlusal and linguo-occlusal walls are parallel and make a 90-degree angle with the pulpal floor.
- Mandibular bucco-proximal wall angle with the gingival floor is acute at 80 degrees, while the linguo-proximal wall angle is acute at 85 degrees.
- Maxillary bucco-proximal wall angle with the gingival floor is 90 degrees, and the linguo-proximal wall angle is acute.
Proximal External Outline
- The proximal external outline's shape is triangular, which conserves tooth tissue, provides retention, and matches the morphology of the proximal surface.
- The outline extent depends on the carious lesion's size, the need to break contact with adjacent teeth, and convenience for placing and finishing the restoration.
Gingival Floor and Flare
- The gingival floor should have a C-shape to prevent unsupported enamel.
- The width of the gingival floor is determined by being 0.5mm into dentin, based on enamel thickness.
Retention Features
- Retention in the occlusal segment is provided by dovetails, wall direction, and defined line angles.
- For the proximal segment, retention relies on triangularity, defined angles, and "U" shaped grooves.
- Retention in the proximal box is entirely located in dentin.
Hand Instruments and Tools
- Essential hand instruments for Class II prep include chisels (15-8-12), hatchets (15-8-14), GMT, and angle formers.
- Wedges are used to depress interproximal gingiva, prevent injury to soft tissue, and minimize seepage of saliva through the rubber dam.
Cavity Preparation Techniques
- Medial GMT can plane the gingival cavosurface margin, bevel mesio-pulpo axial line angle, and accentuate retention grooves in the disto-proximal box.
- Distal GMT serves to plane the gingival cam of the disto-proximal box, bevel disto-pulpo-axial angles, and enhance retention grooves in the mesio-proximal box.
Diagnostic Techniques
- Class II carious lesions are diagnosed using bitewing radiographs.
- Lesions are identified in radiographs when they penetrate at least two-thirds into the enamel towards the DEJ.
Operational Guidelines
- The occlusal external outline of the proximal box is determined by the extent of carious lesions and the need to break contact with adjacent teeth.
- A minimum separation of 0.3mm should exist between the gingival cavo surface and the adjacent tooth's proximal surface.
Additional Considerations
- Proximal depth at the pulp-axial line angle is greater than at the gingival floor due to varying enamel thickness.
- Proximal contact points in maxillary teeth typically lie towards the buccal side.
- The reverse curve allows preservation of cuspal triangular ridges and facilitates an angle between proximal walls and the tangent of the proximal surface.
Instrumentation for Examination
- Examination instruments include a mouth mirror, explorer, calibrated condenser, and cotton pliers.
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Description
This quiz focuses on the essential principles of Class II cavity preparation, highlighting key concepts such as GV Black's approach. It covers outline form, resistance and retention, and considerations for pulpal floor depth. Perfect for students learning dental cavity techniques.