Hi Bruno. There can be risks to any dental procedure and y/our dentists would explains these to you before the treatment commences. Crowns can be placed over existing healthy teeth. This would be an "elected" procedure and the risks would be yours to take. Crowns can be made into any shape or colour. Having long canines may affect your mastication. Your jaw is meant to slide along your canines (canine guidance) while you chew your food. You may be uncomfortable having vampire fangs over a long period. Sincere regards Michael.