partial dentures design

Question 1

Kennedy Classifications

Answer 1

Class I- Bilateral free end saddle
Class II- Unilateral free end saddle
Class III- Unilateral bounded saddle (doesn’t cross
the midline)
Class IV- Anterior bounded (crosses midline)

Question 2

Craddock Classifications

Answer 2

Tooth borne (I) - Teeth provide hard tissue resistance to occlusal loading, i.e when there is abutment teeth with support on bounded saddles - 1
Mucosa borne (II) - Large coverage provides resistance to occlusal loading, i.e when the vertical biting force of the denture is resisted
entirely by soft tissue
Tooth and Mucosa Borne (III) - Reduced number of teeth and large edentulous saddles, i.e large free end saddle with mesial rest and therest is mucosal support

Question 3

With reference to the basic principle of partial denture support, where would the supporting component be positioned on tooth 14?

Answer 3

Mesial occlusal rest due to the saddle being free ended

Question 4

On surveying the study cast you observe that: 14 presents a useable undercut (0.25mm) on the buccal aspect; 27 presents a useable undercut (0.25mm) on distal buccal aspect; 23 does not present a suitable undercut for a direct retainer (clasp).

Describe one clinical option that would facilitate a retainer being placed on 23?

Answer 4

The build up of composite on the bulbosity on the labial surface to create an undercut that would be suitable for a clasp

Question 5

What pattern of retention would be the best in this situation and which teeth would be involved?

Answer 5

Direct retention via clasps on the 14, 23 (after clinical adjustment) and 27 which would prevent vertical displacement of the denture. Indirect retention via the matching rests to prevent horizontal displacement

Question 6

With reference to the basic principle of partial denture retention, what type of clasps could be considered for each abutment tooth?

Answer 6

Ring clasp on the 27, I-bar clasp on the 14 and 23

Question 7

With reference to the basic principle of connection & stability, what would be the default choice of connector in this case?

Answer 7

Cobalt Chrome Ring

Question 8

If required, which component(s) provide indirect retention?

Answer 8

Claps on the 27 and 14