Dentists' knowledge of prosthodontics (2)

Advantages:

The abutment is less stressed and the alveolar ridge is more stressed, which preserves the survival time of abutment.

The lingual side does not need anti-arm, which is comfortable and can be physiologically stimulated.

Beautiful appearance, low dental caries rate and more gum exposure.

The proximal bracket has less torsion on abutment and less squeezing effect on gingival tissue of distal abutment.

RPA snap ring assembly:

Composition: near? Bracket, adjacent panel, Aker buckle arm

The function of indirect retainer:

1. Avoid vertical rotation of denture and reduce the damage of abutment caused by rotation.

2. Resist the lateral movement of the denture and prevent the denture from swinging.

3. Balance, keep the denture stable and prevent the denture from rotating.

4. Disperse the resultant force and reduce the load of abutment and its supporting tissues.

The denture is unstable;

Upper arch

sway

Radial

water channel

The relationship between indirect retainer and fulcrum line;

Fulcrum line: a line connecting two points of the supporting object, a line connecting the main base bracket or a line connecting the bracket and the distal free end.

The indirect retainer is far away from the gap side and outside the fulcrum line.

5. Dalian connector

A. role:

B. Requirements

C. types

Classification of dentition defect and removable partial denture

Kennedy dentition defect classification

Kennedy classified dentition defects into four categories according to the positional relationship between saddle bottom and abutment, mainly according to the posterior alveolar ridge.

The first type: the saddle bottom of denture is at the distal end of two abutments, and the distal end is the free end, that is, bilateral free missing teeth.

The second type: the saddle bottom of denture is at the distal end of an abutment, and the distal end is the free end, that is, unilateral free missing tooth.

The third type: the saddle base of denture is on one side or both sides, and there are abutments before and after the saddle base.

The fourth type: the denture saddle base is located in front of the abutment, that is, the front tooth is missing, and the abutment is far from the gap.

Gaps other than determining the classification are called modifications, and the number of gaps represents the number of subclasses.

Subclasses only consider the number of extra gaps, not the range.

The fourth category has no subcategories.

Advantages:

It expresses the position of missing tooth space and embodies the relationship between RPD saddle base and abutment. This method is simple and easy to master.

Disadvantages:

Can't reflect the number of missing teeth

Subclasses cannot mark parts.

Cannot represent retention mode.

Classification of Wang Zhengshou

Design principle of removable partial denture

I. Basic requirements

Second, the biological principle

Three. Preserve design principles

4. Selection of abutment

Verb (abbreviation of verb) measures to adjust retention

Principles of stability design of intransitive verbs