The Periodontal - Restorative Interface

Question 1

What relationship does gingival margin have with the crestal bone

Answer 1

Healthy gingival margin appears to maintain a predetermined relationship to underlying crestal bone

Question 2

Biological width =

Answer 2

Biological width = summation of supra-crestal conn. tiss. attachment & junctional epithelium
BW approx. 2.0 - 3.0mm but variable

Question 3

Dento-gingival complex

Answer 3

Question 4

Suggested effects of violating the biologic width

Answer 4

Physical trauma & plaque retention may cause gingival inflammation
Crestal bone resorption & apical migration of dento-gingival complex to re-establish BW

Question 5

Requirements of ideal restoration margin

Answer 5

Shape contributes to minimal marginal opening
Strength of material to resist distortion or fracture during function (CSA)
Good appearance
Convenient to prepare & record by dentist
Easy to locate on die & work with in lab
Contribute to maintenance of periodontal health

Question 6

Location of restorations margins

Answer 6

1908 – Black’s sub-gingival extension for prevention

1970’s Sub-gingival margins challenged
Assoc. with increased incidence & severity of gingival & periodontal disease
Overhanging margins correlated with clinical & radiographic evidence of alveolar bone

Question 7

Supra-gingival margins - why are they good?

Answer 7

Good access / visibility
Convenient to prepare / record impression
Simple to locate & work to in lab
Allows better evaluation of margins clinically
Easier for patients to clean (sub gingival margins are hard to clean)

Question 8

Reasons for sub-gingival margins ?

Answer 8

Extension of dental caries
Sub-gingival fracture of teeth
Previous restoration extended sub-gingival
Mechanical retention (lack of crown height)
Strength (ferrule effect = 1.5mm)
Aesthetics

Question 9

Crown lengthening procedures

Answer 9

Periodontal surgery
Gingivectomy/gingivoplasty
Apically repositioned flaps with bone removal
Orthodontic extrusion

If not enough height, - gingivectomy / gingivoplasty / crown lengthening surgery

Question 10

Design/form of restoration margins ?

Answer 10

• Direct restorations
• Indirect restorations
  Knife / feather edge
  Bevel
  Chamfer
  Shoulder
  Shoulder bevel

Question 11

Fit & quality of margins - what causes them to be PRF?

Answer 11

Open margins
Overhangs (different types)
Micro-porosity
Surface roughness
Shrinkage
All margins are imperfect & collect plaque!

Question 12

Insertion of direct restorations - how to decrease chance of overhangs

Answer 12

Accurately contoured & positioned matrix
Wedges

Question 13

Gingival displacement around margins

Answer 13

Mechanical
Mechanical/chemical
Gingitage
Electrosurgey

Retraction cord
Electrosurgery

Question 14

Restoration contours & Embrasures

Buccal & lingual contours

Answer 14

Emergence profile = tooth profile that emerges from the gingival sulcus
Greater convexity = more difficult to remove plaque
Flat or slightly concave desirable

Note furcation areas and shape accordingly
If emergence profile incorrect, then all other contours will be wrong’s,,.,k

Question 15

Embrasure space

Answer 15

Embrasure form depends upon
Clinical crown height
Root proximity
Cervical contour
Root anatomy
Aesthetics

Question 16

Embrasures

Answer 16

Contact areas in occlusal 1/3 & buccal
Sufficient tooth reduction critical
Embrasure space large enough to allow for normal papilla – avoid impingement of col

Question 17

Embrasures

Answer 17

Contact areas in occlusal 1/3 & buccal
Sufficient tooth reduction critical
Embrasure space large enough to allow for normal papilla – avoid impingement of col

Question 18

Traditional occlusal teachings

Answer 18

Forces directed along long axis
Minimize lateral forces
Contacts in ICP (intercuspal position) / RCP
Anterior & lateral guidance
Occlusal stability

Question 19

Occlusion & periodontal disease

Answer 19

Trauma from occlusion = pathological alterations or adaptive changes which develop in the periodontium, as a result of excessive occlusal forces from premature contacts or parafunction
Primary & secondary occlusal trauma

Question 20

Occlusion & periodontal disease -

What does Trauma in the presence of marginal periodontitis cause

Answer 20

Trauma in the presence of marginal periodontitis increases alveolar bone loss radiographically, BUT loss of connective tissue attachment is controversial

Question 21

Occlusal therapy

Answer 21

May reduce occlusal load by occlusal adjustment of tooth during initial therapy
Can spread load by splinting teeth, (after initial therapy to reduce plaque related inflammation)

Question 22

Occlusal therapy

Answer 22

May reduce occlusal load by occlusal adjustment of tooth during initial therapy
Can spread load by splinting teeth, (after initial therapy to reduce plaque related inflammation)

Question 23

Splinting – suggested indications?

Answer 23

Occlusal trauma
Increasing mobility of teeth
Mobility decreases function
Patient comfort
To retain orthodontically repositioned teeth
To prevent drifting & overeruption
Temporary splints for CRT & surgical treatment

Question 24

Prosthodontics & the Periodontium

Justify replacing missing teeth?

Answer 24

Benefits?
Risks?
“28 tooth syndrome”
“Shortened dental arch concept”

Question 25

Fixed bridges

Answer 25

Types of bridges ?
F-F, F-M, Cantilever, complex
Pontics ?
Level of periodontal support needed?

1. Pontics
   Hygienic / sanitary / wash through
   Bullet shaped
   Saddle / ridge lap
   Modified ridge lap
   Ovate pontic
2. Perio-restorative fixed bridge case

Question 26

Removable partial dentures

Answer 26

Effect on oral environment
Tooth / mucosa support
Materials
Gingival coverage
Design features

• may increase plaque accumulation
• changes in plaque composition
• gingivitis scores increase in 24hr wear

Question 27

Implants and periodontology

Answer 27

When do we extract perio involved teeth in order to place implants?
Are perio susceptible patients more prone to implant bone loss & failures?
Is peri-implantitis common and how do we treat it?

Question 28

Gingival recession management

Answer 28

Management

Preventative / maintenance (NSPT)

Restorative-
Removable prosthesis
Pink porcelain on C & B
Interproximal build up with composite or veneers to close black trangles

Surgical-
FGG
CT Graft
Coronally Repositioned Flaps
Allografts

Question 29

Scope of presentation

Answer 29

The dento-gingival complex
Restoration margins
Restoration contours & Embrasures
Occlusal considerations
Splinting
Prosthodontics
Recession

Question 30

Periodontal aspects of Restorative Dentistry

Answer 30

Supra- gingival margins
Avoid overcontoured restorations
Occlusal stability

Restricted indications for splinting mobile teeth
Hemi-section of extensive furcations
Restricted indications for replacement of lost molars