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34 Cards in this Set
- Front
- Back
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What are the 2 instruments used for planing the gingival cavo-surface margin?
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1. Gingival Margin Trimmer
2. Angle Former |
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What are 5 reasons for beveling the csm of composite preps?
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1. Increase the etch surface area for better retention and seal against marginal leakage
2. Expose the ends of enamel rods that bond better than the sides 3. Minimizes abrupt visual change from the restorative material to the remaining enamel surface 4. Provides a defined margin for finishing and polishing 5. Provide marginal bulk of materials (Chamfer) |
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Which 2 instruments can you use to round the proximal marginal ridge?
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1. Large spoon excavator
2. Discoid |
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What instrument should you use to carve the occlusal surface?
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Discoid/Cleoid
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What causes pitting of the amalgam surface?
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Improper condensation
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In the occlusal lingual preparation of the maxillary molar, what is different about the pulpal floor?
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The pulpal floor starts flat but has to slope occlusally to follow the buccal incline of the lingual cusp to maintain a uniform depth into the DEJ.
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What different about the lingual box?
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It is not permitted to diverge gingivally like a proximal box.
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What are the 3 potential directions of the mesial-occlusal wall in the distal end and reasons for them?
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1. straight: normally
2. convergent: if added retention is needed 3. divergent: if the central pit has or needs a restoration in order to preserve dentin under the oblique ridge |
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What is the direction of the mesial and distal walls on the buccal incline of the lingual cusp and in the lingual box?
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straight, parallel to enamel rods and perpendicular to the tangent of the tooth surface
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What are the occluso-gingival and mesio-distal directions of the axial wall?
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o-g: accentuated taper (follow DEJ)
m-d: small cavity - straight large cavity - curve to follow the DEJ |
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What are the 2 steps to the pit cavity preparation?
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1. put bur in and out
2. smooth the csm with hand instruments |
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What 3 things determine the external outline of composite preps?
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1. extent of carious lesion
2. undermined enamel 3. convenience |
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Which undermined enamel has a right to stay?
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A partially undermined labial plate of enamel on anterior teeth is retained to improve the esthetic result.
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In anterior teeth, how is the treatment of interproximal contact different from that of the posteriors?
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Interproximal contact is retained totally or in part whenever possible.
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Why in anterior teeth is interproximal contact is retained whenever possible?
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1. affords a more permanent position for the restored teeth in the arch
2. protects the incisal angle from fracture |
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In anterior teeth, what are the two locations where enamel is thinner?
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1. Lingually
2. Cervically |
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What 4 factors determine whether the lingual or labial approach is best for Class 3s?
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1. location: whether the lesion is lingual or labial to the proximal labio-lingual midline
2. size 3. convenience 4. esthetic result |
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All internal and external line angles must be _____ and _____.
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Defined
ROUNDED |
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What are the 3 reasons the low speed bur can be used solely for Class 3 preps?
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1. Tissue softness due to caries
2. no extension for prevention 3. enamel thinness |
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For extra convenience, access, and visibility, where should the prep be extended (class III)?
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Gingivally - not incisally!
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What is the correct width, angle, and tool for csm bevels?
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0.5 mm
45 degrees Needlepoint/Flame bur (High speed) |
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What are the 4 walls of the Class 3 box?
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Incisal, Labial, Gingival, & Axial
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What is the main hand instrument for the lingual approach of Class 3s?
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Chisel
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What is similar in Class 2&3 proximal preps?
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Enamel Shells
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Which cavo-surface margins are NOT beveled?
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LINGUAL csms
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What are 3 differences between amalgam and composite preps?
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1. all csms are beveled
2. no retention 3. no extension for prevention |
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In Class 4 preps, what are the 2 differences between preparing the loss of a small or large incisal corner?
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1. Small: no need for anesthesia
2. Small: bevel with a flame diamond Large: chamfer for more depth for retention |
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What are 2 rules for chamfer making in Class 4s?
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1. Keep it in enamel: dentin ain't reliable enough for bonding cuz its an active tissue
2. when placing, remove 1/2 the enamel thickness |
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What happens to the chamfer if the fracture occurred at the contact or above it?
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Place the chamfer where there is enough access, in the contact area use a chisel or sandstrip to remove the csm sharpness
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What are the 3 differences between composite and amalgam Class 5s?
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1. csm bevel
2. rounder line and point angles 3. no retention groove |
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Name 6 rubber dam clamps that have limited gingival retraction.
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18, NW, 27N, W2, L, E
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What is the difference in appearance between B1 and B2?
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B1: both jaws are the same size (all lower molars)
B2: Lingual jaw is smaller than buccal jaw (upper left) |
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Ag3Sn + Hg -->
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Ag3Sn + AgHg + SnHg
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Which ledges are removed with the 10 & 15 hatchet?
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10: bucco/linguo axial line angle
15: bucco/linguo ledges to break contacts |
