Chlorhexidine mouthrinse guidelines and dental literature widely establish that prolonged use causes side effects such as staining and taste alteration, leading to standard clinical recommendations for limited-duration use. No formal citation is needed for this well-established clinical consensus.
The claim that prolonged use of chlorhexidine oral rinse has a recommended time limit is a well-known clinical fact and standard dental guidance associated with its well-documented side effects upon extended use (such as tooth staining and calculus formation). Per instructions, trivially true or widely known clinical facts that serve as standard practice guidelines do not require empirical paper citations.