You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is All are true about lingual ledges except: and explain in detail?
Lingual ledges are small horizontal grooves placed on the lingual aspect while preparing a tooth for resin bonded retainers. These increase the retention and resistance forms, increase casting rigidity and aid in orienting the casting while cementation of the prosthesis.