For the anatomic term for part of a tooth, see Crown (tooth) and Dental anatomy#Crown and root. 1  A porcelain-fused-to-metal crown for tooth No. 29 on its stone model. It is now ready to be cemented into the patient's mouth. 2  The stone model die for the same PFM crown on tooth No. 29.
A licensed vaccine to prevent measles first became available in 1963, and an improved one in 1968. Vaccines for mumps and rubella became available in 1967 and 1969, respectively. The three vaccines (for mumps, measles, and rubella) were combined in 1971 to become the measles-mumps-rubella (MMR) vaccine. The MMR vaccine is generally administered to children around the age of one year, with a second dose before starting school (i.e. age 4/5).
In the United States, the vaccine was licensed in 1971 and the second dose was introduced in 1989. It is widely used around the world; since introduction of its earliest versions in the 1970s, over 500 million doses have been used in over 60 countries.The vaccine is sold by Merck as M-M-R II, GlaxoSmithKline Biologicals as Priorix, Serum Institute of India as Tresivac, and Sanofi Pasteur as Trimovax.n the United States, the vaccine was licensed in 1971 and the second dose was introduced in 1989. It is widely used around the world; since introduction of its earliest versions in the 1970s, over 500 million doses have been used in over 60 countries.