Typically, when patients are faced with replacing lost teeth, they have 3 choices to pick from. Plastic removable teeth, partial dentures, can be fabricated to cover the area. Although the least expensive option, it tends to be the least popular because it needs to be removed, it's bulky in the mouth, and prone to fracturing. The second option available would be a porcelain cementable bridge. This has the advantage of being cemented into place, however, they are tricky to cleanse, and I agree with your dentist, that it unnecessarily destroys the tooth structure of the surrounding teeth. Dental implants should be your first consideration to solve your problem. They don't require surrounding teeth to be shaved down, they are not susceptible to decay, and are secured firmly in place. They act and feel like natural teeth.