R_Bibb_Medical_Modelling_The_Application_of_Adv.pdf

232 Medical modelling
tasks associated with spruing and casting. Although the Perfactory ® pattern
cast well, the accuracy was poor due to distortion infl icted on the fl exible
pattern during handling. The stiffer patterns produced by SL were easy
to handle, accurate and produced satisfactory results. The layer effect
exhibited by all RP processes was not evident after fi nishing and the difference
between the high-resolution and standard SLA-250 patterns was
negligible.
The techniques undertaken and described above outline a stage in the
development of machine-produced RPD frameworks and point to many
possible advances that can be achieved in the future. The application of
CAD would allow access to new RP technologies that build parts directly
in metal alloys, including chromium-cobalt and stainless steel. Sacrifi cial
pattern manufacture and casting may be eliminated altogether. This will be
explored in future studies.
The introduction of digital design and RP production into current practices
would present a signifi cant change in the fi eld of dentistry and this is
unlikely to happen quickly. Studies so far have shown how CAD and RP
may be applied and some principles have been developed and established.
Possible future benefi ts and the potential shortfalls have also been
discussed.
6.13.5 References
1. Hughes C W, Page K, Bibb R, Taylor J, Revington P (2003), ‘The custom-made
titanium orbital fl oor prosthesis in reconstruction for orbital fl oor fractures’,
British Journal of Oral and Maxillofacial Surgery, 41, 50–53.
2. Bibb R, Brown R (2000), ‘The application of computer aided product development
techniques in medical modeling’, Biomedical Sciences Instrumentation, 36,
319–24.
3. Van der Zel J, Vlaar S, de Ruiter W, Davidson C (2001), ‘The CICERO system
for CAD/CAM fabrication of full ceramic crowns’, Journal of Prosthetic Dentistry,
85, 261–7.
4. Williams R, Bibb R, Rafi k T (2004), ‘A technique for fabricating patterns for
removable partial denture frameworks using digitized casts and electronic surveying’,
Journal of Prosthetic Dentistry, 91 (1), 85–8.
5. Williams R, Eggbeer D, Bibb R (2004), ‘CAD/CAM in the fabrication of removable
partial denture frameworks: A virtual method of surveying 3-dimensionally
scanned dental casts’, Quintessence Journal of Dental Technology, 2 (3),
268–76.
6. Bibb R, Freeman P, Brown R, Sugar A, Evans P, Bocca A (2000), ‘An investigation
of three-dimensional scanning of human body surfaces and its use in the
design and manufacture of prostheses’, Proceedings of the Institute of Mechanical
Engineers Part H, Journal of Engineering in Medicine, 214 (6), 589–94.
7. Budtz-Jorgensen E, Bocet G (1998), ‘Alternate framework designs for removable
partial dentures’, Journal of Prosthetic Dentistry, 80, 58–66.