Which type of teeth requires more parallel preparation?

Molars require more parallel preparation due to their unique anatomical features and functional roles. These teeth are generally larger and possess multiple cusps that can vary significantly in size and shape. To ensure an appropriate fit for prosthetic appliances, like crowns or bridges, molars necessitate a preparation that allows for the precise alignment of these devices with the adjacent and opposing dentition.

The parallelism in preparation is crucial to facilitate proper seating and to minimize any potential for movement or dislodgment of the prosthetic restoration. Additionally, maintaining parallel lines helps in achieving an optimal retention form, especially in molars, where the forces during chewing are substantial. This is particularly important because molar preparations must also account for the occlusal load during function, which can greatly affect the longevity and stability of the restoration.

While other teeth do require preparation, molars demand a more careful approach with more pronounced parallelism due to their position in the mouth and the degree of stress they encounter during daily function.