Final answer:
In dentistry, a principal point should be fitted to a prepared canal with a definite apical seat, giving a 'tug back' sensation to ensure a proper seal without being too loose or overextending beyond the apex. option A is the correct answer.
Step-by-step explanation:
When fitting a principal point to a prepared canal in dentistry, the primary consideration is to have a definite apical seat, often described with the sensation of "tug back." Tug back refers to the slight resistance a dentist feels when trying to withdraw a point that fits snugly at the apical portion of the prepared root canal. This ensures that the point is neither too loose, which could result in a poor seal and potential canal contamination, nor too tight, which could lead to overextension and damage beyond the apex. The goal is not to fit the point to the exact apex or to be a specific distance from the apex, but to ensure that the point fits well within the confines of the prepared canal and provides a proper seal.
The primary consideration when fitting a principal point to a prepared canal is that the point should fit to the exact apex. When fitting a principal point to a prepared canal, the primary consideration is that the point fit to the exact apex. This means that the point should be placed accurately at the apex or tip of the canal. It should not be placed too far away or too loosely within the canal.