Preventive prosthodontics emphasizes the importance of any procedure that can delay or eliminate future Prosthodontic problems. The concept of overdenture is far from new. It is almost 150 years back when Ledger (1856) encouraged the idea of leaving roots of natural teeth to support a complete denture. It provides better function than conventional tissue supported complete denture through a variety of parameters such as improved masticatory efficiency, preservation of proprioceptive response, better stability support and retention, aesthetic excellence, less trauma to supporting tissues. This book summarizes overdentures and attachments and their advantages and treatment planning.