Treatment of carious lesions

Tooth damaged due to caries will affect the structural integrity and providing a perfect restoration can help a long standing restoration. Question and answers related to the restorations and the procedures are discussed here.

1. What are the two main resistance and retention considerations while preparing the cavity?

Having flat pulpal and gingival floors to resist the occlusal forces and the adjacent walls have to be at right angles to the floors so that the finished restorations do not skid or rotate. Also incorporating sufficient undercuts in the cavity will keep the restoration from being dislodged.

Ref: Lloyd Baum,Ralph W.Phillips,Melvin R.Lund.Textbook of Operative Dentistry.W.B.Saunders company;1985; 143

2. How do hardness and texture of the dentin serve as indicators of dentin removal curing cavity preparation?

The soft carious dentin is removed during cavity preparation. Tactile sense with a hand excavator is more reliable than a bur to detect diseased and healthy dentin. After removing the soft dentin, the dentin may still be discolored. But healthy dentin will be very resistant to the excavator, when compared to carious dentin.

Ref: Lloyd Baum,Ralph W.Phillips,Melvin R.Lund.Textbook of Operative Dentistry.W.B.Saunders company;1985; 145

3. Why is paste form of calcium hydroxide is preferred for cavity lining?

The paste form ( Dycal) is preferred because it is easily applied and hardens rapidly, can be applied with the same instrument used to mix it and it can be placed very precisely to avoid random smearing of the other areas.

Ref: Lloyd Baum,Ralph W.Phillips,Melvin R.Lund.Textbook of Operative Dentistry.W.B.Saunders company;1985; 149

4. How is dycal applied in the cavity?

Depending on the handling convenience, any instrument can be used based on the size and location of the preparation. Usually back side of the small excavator will be useful in placing the cement.

Ref: Lloyd Baum,Ralph W.Phillips,Melvin R.Lund.Textbook of Operative Dentistry.W.B.Saunders company;1985; 150

5. How is the structural integrity of the tooth affected by the carious process?

Tooth damaged due to caries can affect the structural integrity like a fracture in the marginal ridge will cause wedging of food between teeth. Loss of proximal contact causes mesial drift and migration of teeth. Cuspal breakage may cause pain and discomfort and loss of occlusal contact from the opposing tooth allows it to erupt into the space interfering with the plane of occlusion.

Ref: Lloyd Baum,Ralph W.Phillips,Melvin R.Lund.Textbook of Operative Dentistry.W.B.Saunders company;1985; 151

6. While manipulation of zinc oxide eugenol cement, why dry cotton is preferred than metal or plastic instrument?

The zinc oxide eugenol cement mix is carried to the cavity with the tip of the explorer and a small pellet of cotton grasped in cotton ploiers is used to pat the material and mold it within the cavity. This is because any metal or plastic instrument will adhere to the cement. Additional increments are also added in the similar fashion.

Ref: Lloyd Baum,Ralph W.Phillips,Melvin R.Lund.Textbook of Operative Dentistry.W.B.Saunders company;1985; 154

7. Why is molding and shaping of polycarboxylate cement difficult?

The super stickiness of the polycarboxylate cement is a factor that makes it difficult to handle. No substance to coat the instrument seems to prevent the cement from sticking to them.

Ref: Lloyd Baum,Ralph W.Phillips,Melvin R.Lund.Textbook of Operative Dentistry.W.B.Saunders company;1985; 161

8. Why is a hermetic seal important during the healing period in direct pulp capping?

A strong. Intact and non dislodgable cement restoration is needed over the exposure site during the healing period because if the dressing is not secure and breaks during mastication, the pulp comes in direct contact with the oral contaminants and successful healing will be affected.

Ref: Lloyd Baum,Ralph W.Phillips,Melvin R.Lund.Textbook of Operative Dentistry.W.B.Saunders company;1985; 162

9. Why is hydrogen peroxide not used over an open pulp to eliminate traces of the blood?

Hydrogen peroxide causes oxygen bubbles to develop in the chamber when comes in contact with blood and strangulate vessels and impede circulation. So it is not used over exposed pulp. Clean fresh distilled waster or saline is acceptable.

Ref: Lloyd Baum,Ralph W.Phillips,Melvin R.Lund.Textbook of Operative Dentistry.W.B.Saunders company;1985; 164

10. How does the degree and kind of hemorrhage in the exposure site influence the prognosis?

Generally, if the blood is red, flowing freely, with a normal clotting time, the prognosis is good. If the blood is pale and associated with serum exudates, the prognosis is poor.

Ref: Lloyd Baum,Ralph W.Phillips,Melvin R.Lund.Textbook of Operative Dentistry.W.B.Saunders company;1985; 164