The Chamfer finish line is most preferred in fixed prosthodontics because it provides a clearly defined margin with sufficient bulk for the restoration material, especially ceramics and metal-ceramics. It offers better stress distribution and reduces the risk of marginal chipping compared to other finish lines. Additionally, the chamfer design allows for easier impression making and accurate marginal adaptation. It also conserves more tooth structure than a shoulder finish line, ensuring optimal periodontal health and strength of the tooth. This margin design balances esthetics, function, and biological considerations effectively.

Reference: Textbook of prosthodontics, Deepak Nallaswamy, 1st Edition.