Abutment evaluation

1. Dr. Firas Kassab

2. •a tooth, a portion of a tooth, or
that portion of a dental implant
that serves to support and/or
retain a prosthesis
- GPT

3. • The forces applied to the missing teeth are transmitted through
the Pontic, Connectors and Retainers to the Abutment teeth and
are therefore called upon to withstand the forces normally
directed to the missing teeth, in addition to those usualy applied
to the abutment

4. • Better to select VITAL teeth
• Endodontically treated tooth with good seal & complete
obturation
• If coronal tooth structure is lost, strength regained by Dowel
Core, Pin Retained amalgam or composite resin core
• Never in pulp capped teeth

5. • Evaluated for three factors
- CROWN - ROOT RATIO
- ROOT CONFIGURATION
- PERIODONTAL AREA

6. LENGTH OF TOOTH OCCLUSAL TO CREST OF ALVEOLAR BONE
LENGTH OF ROOT EMBEDDED IN BONE
• OPTIMUM RATIO IS 2:3
• RATIO OF 1:1 IS MINIMUM ACCEPTABLE
• AS THE LEVEL OF ALVEOLAR BONE MOVES APICALLY, THE
LEVER ARM OF THAT PORTION OUT OF BONE INCREASES

8. • Roots that are Broader bucco-lingually than mesio distally are
preferable
• Multi rooted posterior teeth with widely separated roots offer
better support than conical or fused roots
• A single rooted tooth with irregular configuration or some
crvature in the apical third is preferrable
• A well aligned tooth will provide better support

9. • It includes root surface area & periodontal status
• Regarding Root surface area, Ante in 1926 suggested a
law – Ante’s Law
“this law states that abutment teeth should have a
combined pericemental area that the tooth or teeth to be
replaced”