Porcelain veneers are shells of porcelain which are glued to the outer surface of the tooth. They are mostly used to improve the esthetics and smile by correcting the shape and color of the teeth and by closing the gaps in between the front teeth. Crowns are used to cover the tooth 360 degrees to reinforce the strength of the tooth. Crowns also improve the esthetics by changing the shape and color of the teeth but they need more teeth preparation compared to veneers.