Reference points in endodontics in posterior teeth

# Reference points in endodontics in posterior teeth are:
A. Buccal and lingual surfaces
B. Pits
C. Cusp tips
D. Marginal ridges

The correct answer is C. Cusp tips.

Gross occlusal reduction should be done on any decayed or filled posterior tooth undergoing root canal therapy.

This reduction should be done before rubber dam placement to check occlusal clearance in all excursive movements. It should be done before the first endodontic treatment, rather than after, in order not to disturb cuspal reference points used to establish proper length of the tooth.

CLICK HERE FOR MORE MCQs 

Palatal root of maxillary first molar is curved:

# Palatal root of maxillary first molar is curved:
A. Mesially
B. Buccally
C. Lingually
D. Distally

The correct answer is B. Buccally.

Palatal root of upper first molar is often curved buccally at apical third. It has the largest  diameter and offers easiest access of all the three roots.

CLICK HERE FOR MORE MCQs 

Root canal of maxillary first molar difficult for instrumentation

# Root canal of maxillary first molar difficult for instrumentation is:
A. Mesiobuccal
B. Distobuccal
C. Distolingual
D. Mesiolingual

The correct answer is A. Mesiobuccal.

Mesiobuccal root has greatest distal curvature and is narrowest of all the three roots. It is flattened in mesiodistal direction. Sometimes, it contains a fourth canal. 

CLICK HERE FOR MORE MCQs 

Conditioning for GIC restoration

# In a cavity to be restored with GIC, it should be conditioned with:
A. Water
B. Polyacrylic acid
C. Phosphoric acid
D. Hydrochloric  acid

The correct answer is: B. Polyacrylic acid.

-Following completion of any cavity, there will be a smear layer left on the surface and floor.
- To remove this smear layer, 10% polyacrylic acid is applied and allowed to remain in place for 10 seconds.

CLICK HERE FOR MORE MCQs