Operative Final Exam - Lectures: Amalgam Restorations and Quadrant Dentistry Flashcards
If the mouth was divided into a sextant, how many sections would there be and name their location.
- 6 sections
- maxillary left, right, and anterior
- mandibular left, right, and anterior
What is quadrant dentistry?
treating all of the affected teeth in 1 quadrant/sextant during the same visit as opposed to 1 tooth at a time
What are the advantages of quadrant dentistry?
- less number of appointments for patient
- less discomfort for patient
- more efficient and productive for dentist
What are the disadvantages of quadrant dentistry?
- increased chairside time
- does not follow the ideal treatment sequence (3 phases: get the patient out of pain, remove caries, and then restorative care)
What are some reasons to perform (indications) quadrant dentistry?
- adjacent interproximal caries (“kissing caries)
- multiple faulty restorations
- pediatric dentistry
- medically compromised patients
What are some reasons not to perform (contraindications) quadrant dentistry?
- lack of dental experience
- patient who have TMJ dysfunction syndrome
- patients who cannot stay in a reclined position for a long time
What is the formula of a low-copper amalgam?
Ag3Sn (gamma) + Hg –> Ag2Hg3(gamma1) + Sn7-8Hg(gamma2) + Ag3Sn (unreacted gamma)
What is the weakest phase of low-copper amalgam?
gamma2
What is the most corrosion-prone phase in low-copper amalgam?
gamma2
Which type of amalgam (high or low copper) has high creep? Why?
low-copper because gamma2 doesn’t prevent gamma1 from sliding
What is creep?
the tendency of a solid material to flow or permanently deform under constant cyclic loading over time
What percentage of copper is considered a low-copper amalgam? A high-copper amalgam?
- low-copper amalgam = 6% Cu
What is the difference in phases between high-copper and low-copper amalgams?
high-copper amalgam has a n’ phase of Cu6Sn5 so there is no gamma2
What is the composition of gamma?
Ag3Sn
What is the composition of gamma1?
Ag2Hg3
What is the composition of gamma2?
Sn7-8Hg
What is the composition of n’?
Cu6Sn5
What are the two types of high-copper amalgams?
- admixed alloy (lathe-cut and spherical)
- unicompositional (spherical)
What is the difference in the reaction formula of admixed alloy and unicompositional high-copper amalgams?
- admixed alloy has two steps: first step in which gamma2 forms and then second step in which n’ forms so no gamma2 is left
- unicompositional is only one step in which n’ forms (in addition to gamma1)