RECONSTRUCTION OF A MAXILLARY ARCH (KENNEDY CLASS IV) INVOLVING CROWNS IN COMBINATION WITH A METAL-BASED REMOVABLE PARTIAL DENTURE By Jako Fouche In partial fulfilment of BTech: Dental Technology

CONTENTS  Patient history  Condition and background  Current situation  Possible treatment options  Treatment option of choice  Laboratory procedures  References

PATIENT HISTORY  Female  61 years old  Choir singer

CONDITION AND BACKGROUND  5 unit porcelain bridge  Preparations failed  Root canal treatments were done  Acrylic partial overdenture made  Problems with phonetics  Wanted upgrade on aesthetics

CURRENT SITUATION  Kennedy class IV 4  2 x Root canals Red = Crowns Black = Fillings

POSSIBLE TREATMENT OPTIONS  5 unit porcelain bridge a. Post-retained b. Post and Implant-retained  12 unit porcelain bridge  2 x post-retained crowns and cobalt- chromium denture

5 UNIT PORCELAIN BRIDGE (POST-RETAINED) ADVANTAGES  Excellent aesthetics  Less bulky than RPD 2  Very natural feel 2 DISADVANTAGES  Weak anchorage available  Previous preparations failed  Cost ±R4,500.00

5 UNIT PORCELAIN BRIDGE (POST + IMPLANT-RETAINED) ADVANTAGES  Excellent aesthetics  Excellent stability 2  Very natural feel 3  Excellent anchorage DISADVANTAGES  Only option involving trauma  Cost ± R5,000.00

12 UNIT PORCELAIN BRIDGE ADVANTAGES  Best aesthetics  Excellent blending of tooth colour  Removal of existing crowns + fillings  Restoration of entire maxillary arch DISADVANTAGES  Cost ±R8,  Most expensive  Possible heavy metal poisoning

2 X CROWNS ON POSTS WITH COBALT-CHROMIUM DENTURE ADVANTAGES  Cost ±R2,  Least expensive  Good aesthetics  Better distribution of forces  Good retention DISADVANTAGES  Responsibilities involved 4  Plaque accumulation 5  Abrasive on anchored teeth 5

TREATMENT OPTION MOST SUITABLE  12 Unit porcelain bridge  Current poor restorations  Restoration of entire arch  Improve aesthetics

TREATMENT OPTION OF CHOICE  2 x Crowns on post with cobalt-chromium removable partial denture  Decided by dentist and patient

LABORATORY PROCEDURES  Posts  Porcelain crowns  Cobalt-chromium metal framework with teeth placed for try-in  Acrylic teeth secured on metal framework

POSTS  Posts on 1.3 and 2.2  Out of the bite  In-line with adjacent teeth  Sufficient space for coping and porcelain

PORCELAIN CROWNS  Crowns on posts  Prepared to accommodate metal framework  Mesial surfaces of 1.3 and 2.2 parallel 4  To accommodate guide plates

COBALT-CHROMIUM METAL FRAMEWORK WITH WAX-UP FOR TRY-IN  Horse-shoe shaped major connector  Anterior rests placed on 1.3 and 2.2  Posterior rests interproximally between 2 nd premolars and 1 st molars

 Acker’s clasps on 1st molars  One arm clasps on 2nd premolars  Finished and polished  Senator shade C3 teeth  Placed after excessive trimming  Waxed-up  Ready for try-in

ACRYLIC TEETH SECURED ON METAL FRAMEWORK (final procedure)  Final finishing and contouring of the wax- up  Pack and flask  Cast with denture base acrylic  Trim and polish  Planned to be completed 15 October 2004

REFERENCES 1. Johnson JF. Modern Practice in Crown and Bridge Prosthodontics. USA:WB Saunders Murray HV. Fixed Restorative Techniques. USA:North Carolina Press. 1989: Naylor WP. Introduction to Metal Ceramic Technology. Illinois:Quentessence. 1992: Owen CP. Fundamentals of Removable Partial Dentures. South Africa:UCT. 2000: ; Stratton RJ. An Atlas of Removable Partial Denture Design. London:Quentessence. 1988: ;