RPD DESIGN - BRACING AND RECIPROCATION Flashcards Preview

BDS2 CLINICAL Prosthodontics > RPD DESIGN - BRACING AND RECIPROCATION > Flashcards

Flashcards in RPD DESIGN - BRACING AND RECIPROCATION Deck (13)
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1
Q

When are horizontal forces generated

A

During function by occlusal contacts and by the oral musculature surrounding the denture

2
Q

What do horizontal forces do to a denture

A

Displace the denture in the antero-posterior and lateral directions

3
Q

What are horizontal forces resisted by

A

Placing rigid components of the denture (bracing components) against suitable vertical surfaces on the teeth and residual ridges

4
Q

When can bracing only occur

A

When the denture is fully seated

5
Q

What are lateral forces capable of doing

A

conflicting considerable damage on the periodontal tissues and alveolar bone in the edentulous areas

6
Q

How may bracing on teeth be achieved

A

by means of rigid portions of clasp arms or plates

7
Q

How may bracing be achieved on ridges and in the palate

A

by means of major connectors and flanges

8
Q

When is a clasp effective in its retention

A

in the retention distance

9
Q

What is the retention distance

A

position when the denture is fully seated to where it escapes over the bulbosity of the tooth

10
Q

What should a reciprocal element be doing for it ot be effective

A

should be in continuous contact with the tooth surface as the retentive arm transverses the ‘retention distance’

11
Q

What can effective reciprocation be achieved by

A

○ A clasp arm contacting a guide surface of a similar height to the retention distance
○ A plate making continuous contact with the tooth surface as the retentive arm moves through its ‘retention distance’

12
Q

What happens if a reciprocal arm is not placed on a guiding surface

A

it will loose contact with the tooth before the retentive arm has passed over the maximum bulbosity of the tooth and fail to provide reciprocation

13
Q

Why is reciprocation important

A

The clasp deforms as it goes over the bulbosity - it puts pressure on the tooth which can result in horizontal movement so reciprocation keeps contact with the tooth as the clasp deforms to oppose the horizontal movement and maintain the tooth in its position