R_Bibb_Medical_Modelling_The_Application_of_Adv.pdf

226 Medical modelling
6.80 a = occlusal rest, b = polymeric retention frame, c = lingual bar,
d = acrylic line, e = non-active clasp, f = guide plate.
• Occlusal rests (a in Fig. 6.80) – a combination of two-dimensional
drawing, three-dimensional creation and manipulation tools was used
to create pieces of clay that were copied and located where required on
the teeth.
• Polymeric retention framework (b in Fig. 6.80), lingual bar (c in Fig.
6.80), acrylic line (d in Fig. 6.80) and non-active clasps (e in Fig. 6.80) –
the ‘draw’ tool was used locate curves directly onto the cast surface.
These formed the centre of the frameworks profi le (Fig. 6.81). The
‘groove’ tool was used to defi ne and create the exact oval and square
sectional dimensions as clay.
• Guide plates (f in Fig. 6.80) – Guide plates were created using the same
method as relief creation. The ‘attract’ and ‘smudge’ tools were also
used to build up plate areas and blend them onto the framework
sections.
• Finishing – ‘smooth’, ‘attract’ and ‘smudge’ tools were used to blend the
components together. The ‘buck’ cast was removed, acting as a Boolean
cutting tool to leave just the clay framework.
• Active clasps – the clasps were designed in the same manner as the
non-fl exible parts of the framework, but using the ‘buck’ cast with