Question

1. Describe the function (effects) of the major elements of dental amalgams.

2. Describe, understand, and explain the sequence of steps for the placement and carving of a dental amalgam restoration.

3. Name the instruments and materials used for placement of dental amalgam restorations.

4. Discuss the possible results of poor amalgam placement and carving.

Answer 1

1. Silver causes setting expansion, increases strength, decreases corrosion

-Tin causes setting contraction, decreases strength, decreases corrosion resistance

-Zinc reduces oxidation of other metals, increases life expectancy

-Copper in low copper amalgam functions like silver

2. Steps :-

1. Deliver mouth mirror and explorer to dentist

(Dentist must examine tooth to be restored)

2. Assist dentist in the delivery of anesthetic, topical and local

3. Place isolation items, cotton rolls.

4. Deliver mouth mirror to dentist and inform dentist of the type of bur on the handpiece

5. Adjust the light, retract the patients cheek or tongue and use the HVE and air/water syringe to keep the working area clear for the dentist

6. Transfer the necessary instruments to the dentist during the preparation as needed

7. Rinse and dry prepared tooth for the dentist to evaluate

8. Deliver caries indicator dye to the preparation, wait, rinse, and dry (Repeat until tooth is clear of caries)

9. If the preparation requires a base or liner, mix and deliver to the dentist

10. Activate amalgam capsule and triturate

11. Fill the smaller end of the amalgam carrier and transfer to the dentist. The dentist may want both ends of the carrier filled. Alternate the condenser with the carrier. Continue to supply the dentist with more amalgam until the preparation is slightly overfilled.

12. Exchange the condenser for the burnisher so the dentist can burnish the excess mercury to the tooth surface

13. Deliver the carving instruments of dentists choice until the restoration is complete

14. The dental assistant will continue the HVE to remove particles and for retraction during the continued carving and burnishing

15. The assistant must still use the HVE to remove any pieces of amalgam as well as continue to retract the cheek, lip or tongu

16. Remove all cotton and the dental dam. Rinse and dry the area.

17. Place articulating paper between the maxillary and mandibular teeth to check the occlusion. The patient should bite down carefully and gently so as to not fracture the new restoration. The dentist will continue to adjust the occlusion until the bite is correct. Heavy colored marks will appear on the restoration in areas needing adjustment

18. Inform the patient not to chew on that side of their mouth. The amalgam will continue to harden for several hours after placement.

19. If the patient received anesthetics, inform them to avoid chewing until the anesthetic is gone so as to avoid biting his cheeks or tongue

20. Inform the patient to call the office if they find their occlusion is incorrect. They will need to return to the office for an occlusion adjustment

3. The instruments include :-

mirror, explorer, cotton pliers, spoon excavator, cleoid-discoid

4. Poor results of amalgam placement :-

- Open margin

Results of poor condensation or when an opposing cusp fractures

- Overextension

Thin ledge of amalgam extends beyond the cavosurface margin

- Overhang

Excess amount of amalgam that extends beyond the cavosurface margin

- Premature contact

Areas where the amalgam have been undercarved

- Submariginal area

Results when the margin is over carved created a deficiency of amalgam