A comparison between some paralleling instruments.
Five paralleling instruments, Paramax I, Paramax II, Pontostructor type A,P.P.-instrument and PR-ec-in-dent, were investigated concerning paralleling precision. A number of rows of holes were drilled in aluminium plates fixed to the instruments. The holes were sectioned longitudinally and their inclinations measured in a profile projector. The variance and range of these inclinations were calculated for each make with small values indicating good guiding characteristics. F-tests showed that Paramax I and II had better guiding characteristics than the other makes and that Pontostructor had better guiding precision than Prec-in-dent. All the instruments tested had maximum range values for angular deviation far below that regarded as tolerable. Not only the paralleling characteristics of such instruments should be assessed but also other requirements previously presented in the literature.
D003442:Crowns; D000044:Dental Abutments; D003737:Dental Cavity Preparation / Q000295:instrumentation*; D004867:Equipment Design