Lecture 3 - RPD Surveying

what is a surveyor?

a paralleling instrument used in making a dental prosthesis to locate and delineate the contours and relative positions of abutment teeth and associated structures

what is the path of insertion?

specific direction in which a prosthesis is placed

what is the function of an analyzing rod?

analyzing undercuts of teeth and tissue, determining the proper path of insertion

how is a common path of insertion automatically established?

when all clasps are designed with the model set at the same fixed angle of survey table with the spindle

what occurs when the cast is tilted in the surveyor?

change of guide plane, relocation of the height of contour, undercut change, elimination of soft tissue interferences

what are guiding planes?

two or more vertically parallel surfaces on abutment teeth and/or fixed dental prostheses oriented to contribute to the direction of the path of placement and removal of an RPD, maxillofacial prosthesis and overdenture

what is the function of a survey line?

to mark the largest dimension/height of contour of the tooth

what are the steps of surveying?

identify the most favorable path of insertion -> cast tripod -> undercut analysis -> survey lines -> locate and mark undercuts

what is the function of identifying the path of insertion?

identifying presence of suitable undercuts, eliminate hard and soft tissue interferences, creation of desireable esthetics, establishing appropriate guiding planes

what is the function of tripoding the cast?

recording the cast position in relation to the selected path of placement for future reference

what is the purpose of surveying?

determine desirable path of placement, identifying guide planes, locate undercuts, evaluate soft tissue undercuts, determine restorative procedure and abutment tooth modifications, delineate survey line, evaluate esthetics