Emailed questions

On xrays, you find D2 caries on the proximal surface of a maxillary premolar. When would you NOT do a slot prep? (it has something to do with cariology)

-tba-

What are the 3 things you must always have out on your bracket table?

1) mirror 2) explorer (17 & 23) 3) college pliers

9 steps of cavity prep

1) outline form & initial depth 2) primary resistance form (prevents fracture) 3) primary retention form (prevents falling out of filling) 4) convenience form (modification of ideal form) 5) removal of decay 6) pulp protection if indicated 7) secondary resistance and retention form 8) cavosurface finish 9) debridement of prep

If you are doing a class I amalgam and there is only 0.5 mm of enamel left, how far do you carry the prep into dentin?

1.2 mm amalgam must be 1.7 mm in depth (0.5 mm + 1.2 mm = 1.7 mm)

Tell me the difference between a 1556 burr and a 56 burr. And if you're really good, tell me about a 556 burr. And if you're really really good, what is the length of the cutting portion of the burr and what is the diameter.

1556 is crosscut, curbside, 56 is straight fissured, 556 is straight fissured crosscut Diameter is 0.8mm and cutting length is 3.8mm

How soon after an amalgam is placed can the patient eat (chew on it)?

At least 1 hour

Rounding the axial-pulpal line angle is what step of the prep?

Beveling the axio-pulpal line angle is part of the Resistance Form step

You are about to restore #13 DO and #14 DO with composite. Which one would you restore first? Same scenario as above and you are going to restore with amalgam. Which one would you restore first?

Composite - order doesn't matter Amalgam - you would do #13 first because you might accidentally touch the still soft amalgam while you're working on #14

What is the most common cause of sensitivity after placing a composite restoration? (has nothing to do with technique)

Due to exposure to moisture. The mechanical bond between dentin and dental adhesive is compromised leading to a gap formation, which exposes part of dentin. It is called DE-bond.

I am sure you all remember the 9 steps of cavity preparation, here is a little question. You are about to prepare an MO on tooth #30, which step(s) are involved in preserving the uninvolved marginal ridge?

For the cavity prep/uninvolved marginal ridge question above, it's: Step 1: outline form Step 3: primary retention form

Why would you not plane the gingival margin of a class II prep?

If we go deep enough, we will go into dentin and there would be no unsupported enamel rods Bucklan said (root surface)

What is the last step of rubber dam placement?

Inverting the dam

Can you condense composite with pressure?

No, it just squishes

In a Class V preparation, where do you break contact?

Nowhere, should be centered MD

Band is in place, held with a V3 retainer. Wedge is in place. What would you do to make sure you have good contact with the adjacent tooth? (should also be done for amalgam - has something to do with the band)

Push the band with a small burnisher to make sure there is no gap between the drilled tooth and the band to prevent overhang of the filling materials

Amalgam is easier to obtain contact due to the fact that you can

condense amalgam with pressure

The tapering form in the proximal box of a Class II is what step of cavity preparation?

step 3 - retention form

Amalgam preps: all the steps of cavity preparation must be strictly adhered to. So the preps must be into dentin, approximately 1/2mm. Why??? It has nothing to do with the thickness of amalgam, which is important.

the dentin is more flexible and therefore augments the mechanical strength of the amalgam material so that it can better withstand the forces of mastication. explanation: As Dr. Hirata explained, the enamel's incredible strength is a function of its being supported by the more flexible, less mineralized dentin. He used the example of plate glass adhered to a wall using a rubberized lining. As a result, the glass is far more shatter-resistant. Similarly, the amalgam material's inherent strength is augmented by the underlying support of the dentin in order to better withstand the punishing masticatory (and other mechanical) forces to which it will be subjected in the oral cavity.

Decay in smooth surface and pit and fissures have a V shape in both enamel and dentin. Where is the base of the V in the enamel of an occlusal pit?

the point on the surface of the enamel / dentin occlusally for pits and fissures? It would be the opposite for smooth surfaces as indicated by the image.

Which rubber dam do we use?

the purple nylon rubber dam (the green rubber dam are for children in the 2nd year)