The Procera crown â Procera is a milled ceramic on the inside with a more traditional porcelain baked onto the outside. The advantage of Procera is its exceptional strength. However, the milled ceramic core is opaque white, so many cosmetic dentists feel that it isnât as natural-looking as the more translucent materials.
1 February: On February 15 the Romans celebrated the festival of forgiveness for sins; (februare, Latin to purify), 2  March: Mars, the Roman god of war,  April: Roman month Aprilis, perhaps derived from aperire, (Latin to open, as in opening buds and blossoms) or perhaps from Aphrodite, original Greek name of Venus,
The origin of the term cloud can be found in the old English clud or clod, meaning a hill or a mass of rock. Around the beginning of the 13th century, it was extended as a metaphor to include rain clouds as masses of evaporated water in the sky because of the similarity in appearance between a mass of rock and a cumulus heap cloud.