TOPIC: FIXED PARTIAL DENTURE

🎯 KEY POINTS:

🔸Maxillary first molar has maximum root surface area of 433 mm2 and Mandibular first molar has root surface area of 431 mm2; among Anterior maxillary teeth, Canine has maximum root surface area of 273 mm2 and Mandibular central incisor has minimum 154 mm2; among Posterior mandibular teeth, first premolar has minimum root surface area of 180 mm2.

🔸Tooth preparation becomes difficult, if the long axis of the tooth diverges or converges more than 25 degrees from parallelism.

🔸Multirooted posterior teeth provide better periodontal support than single conical roots.

🔸Bending or flexion of the fixed bridge varies directly to the cube of the length and inversely with the cube of cervicoincisal thickness of the pontic.

🔸More parallel the opposing walls of the preparation, more will be the retention.

🔸Optimum taper for prepared walls is 2–6 degrees.

🔸For short clinical crown, additional retentive features such as grooves, pins, slots and boxes are advocated.