A 24 year old male presents to OPD with sensitivity to cold water. On intraoral examination, 46 is carious and dentist decides to restore the teeth with amalgam restorative material with zinc phosphate base. Which of the following is NOT a modification of this cement?
Correct Answer: Resin modified cements
Description: Copper cements are basically modified zinc phosphate cements. Silver salts or copper oxide are sometimes added to the powders of the zinc phosphate cements to increase their ‘antibacterial’ properties. Copper cements gradually fell out of favor because of their poor biological properties. It was highly acidic and the copper was considered toxic to the cell.
This may have been due to the extremely high copper content (97%) in certain cements (Ames). There has been a renewed interest in copper cements recently. New formulations have come out with lower copper content (2%). It is claimed that these new generation copper cements are safe and is especially recommended for indirect pulp capping and where there is active caries.
COMPOSITION
Copper oxide (if cuprous oxide is used—cement is red, if cupric oxide is used, the cement is black)
Zinc oxide
Liquid used is clear phosphoric acid
Key Concept
Copper phosphate and silver phosphate cements were developed to impart antibacterial properties and fluorophosphate cements to impart anticariogenic properties to the zinc phosphate cements. However, these materials are not in use now as they possess many disadvantages compared to conventional zinc phosphate cements.
Reference: Mannapallil p; 98
Category:
Dental
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now