Do lumineers damage your real teeth?

Lumineers are definitely long term or permanent restorations. They are a brand of porcelain veneers. They do not need to be removed or replaced unless something deteriorates relative to your tooth structure supporting the veneer or the veneer itself. They do not damage your teeth. If you maintain the health of your teeth by daily hygiene and periodic professional cleanings and exams, your veneers/Lumineers can potentially last a life time and never cause any damage to your teeth. 

Lumineers are meant to be a permanent restoration. They don't have an expiration date. At some point you will probably want to replace them due to improvements in technology or changes in your mouth. They are not considered a temporary restoration so you need to make sure you are committed to the result they create for the long term. Removing Lumineers can damage the tooth structure underneath if the dentist isn't careful. Most patients that want Lumineers/ veneers don't want them removed.