الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Polymethyl methacrylate (PMMA) has been the most popular
material used for denture fabrication since its introduction in 1937,
it has several advantages. The traditional use of the metal clasp
materials as cobalt chromium Co-Cr hampers esthetics, increases
the weight of the prosthesis and leads to allergic reactions. All these
problems have led to the introduction of thermoplastic resin
materials.
More recently, the thermoplastic monomer free semi-rigid
microcrystalline polymer (karadent by TCS, INC, USA) is
introduced to the market and became a good alternative framework
material for removable denture construction.
Twelve mandibular bilateral partially edentulous male patients
(Class I Kennedy classification) were selected for this study and
randomly divided into two equal groups, control group received a
mandibular removable partial denture (RPD) constructed of Cobalt
Chromium and test group received a mandibular removablepartial
denture (RPD) constructed of the thermoplastic semi-rigid
microcrystalline polymer material (karadent).
Clinical evaluation were carried out for every patient at
insertion, 6, and 12 months by recording the gingival index and
pocket depth scores at mesiobuccal, midbuccal, distobuccal,
mesio-lingual, midlingual and distolingual of each abutment tooth.
The average of these records was calculated and recorded, the mean
was calculated and then the patient recalled for reassessment of oral
hygiene and gingival health.
Summary and Conclusion
(84)
Radiographic evaluation were carried out for every patient at
insertion 6, and 12 month by making radiographic records to
evaluate Changes in bone height and width of the residual ridge,
carried using CBCT radiography.
The mean of changes were collected, tabulated, and statistically
analyzed. The following results were obtained:
1. Bony changes of the supporting structures was greater in
Karadent than in Vitallium in both sides of theridge.
2. Pocket depth scores were greater in Vitallium than in Karadent
in distal abutments of both sides.
3. Gingival index scores were greater in Vitallium than in
Karadent in distal abutments of both sides.
Conclusion
RPD effect on the supporting structures of Kennedy class I
cases is an ongoing process, controllable rather than stoppable by
addition of distal implants and alteration of materials of RPD
components.
Within the limitations of this study, it was concluded that:
1) The use of karadent with its superior properties, is better
accepted by the patients, regarding esthetics.
2) The metallic partial denture appears to make less adverse
effect on the supporting bone in Kennedy Class I partially
edentulous patients than semi rigid thermoplastic ones ( karadent ).
3) The abutment teeth reacted more favorably and offers superior
results regarding gingival condition around the terminal abutment
with the use of the thermoplastic semi-rigid microcrystalline
polymer (karadent).
Summary and Conclusion
(85)
Recommendation
The thermoplastic PRD lacks an important factor of the
traditional PRD, in particular, a rigid framework. Therefore, the
recommendation of this study is to reinforce it with metal (hybrid
design) to provide the PRD with sufficient rigidity with a metallic
major connector and sufficient support with metallic rests and to
compare its effect on supporting structure of distally extended
cases with cobalt chromium RPDs