occlusal adjustments prior to single denture · mandibular single denture: options other than...

Single Denture

Dr: Hussein Abd El-hady Hussein Taha

Lecturer of Removable Prosthodontics and Implantology

Faculty of Dentistry – Minia University

Definition:

A single complete denture is a complete denture that occludes against some

or all of the natural teeth, a fixed restoration, or a previously constructed

removable partial denture or a complete denture.

*Construction and delivery of single complete dentures is more

complicated than the delivery of upper and lower complete

dentures on a patient.

Problems of single denture:

1.The ability of the patient to generate heavy occlusal forces, due to the

existence of opposing natural teeth.

Problems of single denture:

2. Single denture syndrome. This situation is the result of the displacement

of the maxillary denture due to unfavorable occlusal relationship as a

result of tipped, malposed or supererupted natural teeth. It is presented as

mucosal irritation and ridge resorption of the edentulous ridge.

Problems of single denture:

3. The occlusal form of the remaining natural teeth and the uneven occlusal

plan (“mutilated” dentition).

Problems of single denture:

4. Esthetic and phonetic problems due to the fixed positions of the

mandibular teeth.

How to Overcome These Problems

- The primary consideration for a continued success of a

single complete denture is the preservation of that

which remains.

- All fundamental steps in denture construction must be

followed and completed to perfection( without minor

errors).

How to Overcome These Problems

- The occlusal plane of the natural teeth in the opposing

arch must be made harmonious.

- Maximum base extension within functional anatomical

limits (distributed forces over the largest possible area of

supporting structures and the force per unit area kept at

minimum.)

How to Overcome These Problems

Reduction of the forces to which the denture is subjected:

1- Reducing bucco-lingual width of posterior teeth.

2- Maximum tissue coverage.

3- Balanced harmonious occlusion.

4- Use of resilient denture liner in the mandibular denture.

5- Use of implant supported fixed or overdenture prosthesis.

6- Skeletal class III ( Mandible larger than maxilla).

7- Extraction of remaining teeth and complete denture are constructed.

Diagnosis and treatment planning:

1- Complete case history is taken and oral examination is done.

2- Study upper and lower casts are obtained.

3- The upper cast is mounted on the articulator using a face bow.

4- The lower cast is mounted on the articulator using a provisional centric

inter-occlusal record at an acceptable vertical dimension.

5- Eccentric records are made and the condylar elements of the articulator

are adjusted.

Common Occlusal disharmonies:

The remaining molars are often severely inclined Mesially and then

Distal halves super-erupted.

If this situation is left unaltered there would be no occlusion in protrusive

and lateral excursions except for contact on the distal half of the lower

molar.

This results in the maxillary denture being easily dislodged during

functional movements.

Common Occlusal disharmonies:

Treatment:

a) If the molars are not severely tilted they may be reshaped by selective

grinding.

Common Occlusal disharmonies:

Treatment:

b) When tooth reduction is found necessary, the ideal treatment is to

restore the tilted molars with cast gold crowns, onlays, or a fixed bridge if

a large edentulous space exists mesial to the molars.

Common Occlusal disharmonies:

Treatment:

c) If a large space does exist mesial to the tilted molars, another

alternative treatment is to design a removable partial denture that would

restore the mesial half of the molars by using an onlay mesial rest

Common Occlusal disharmonies:

Treatment:

d) If the molars are severely tilted forward and super-erupted, and

modification is not possible, extraction is necessary.

Methods used for detecting occlusal modifications:

Several techniques could be used to determine occlusal modifications

that are necessary prior to denture construction:

I- Swenson’s Technique

II- Bruce Technique

III- Yurkstas’Technique

IV- Boucher’s Technique

Methods used for detecting occlusal modifications:

1- Swenson’s Technique

Upper and lower casts are mounted on the articulator. The upper denture is

constructed. If the lower natural teeth interfere with the placement of the

denture teeth, they are adjusted on the cast and the area is marked with a pencil.

The natural teeth are them modified using the marked diagnostic cast as a guide.

This technique is simple but time consuming.

Methods used for detecting occlusal modifications:

The occlusal plane discrepancy is readily apparent when the denture teeth are

properly arranged.

This discrepancy can only be corrected by restorative means.

Methods used for detecting occlusal modifications:

2- Bruce Technique :

Use of a clear acrylic resin template fabricated over the modified stone

cast. The inner surface of the template is coated with pressure

indicating paste and placed over the patient's natural teeth.

The Modifications are made on the Stone cast. A Clear Acrylic Resin

Template as fabricated over the modified stone cast.

Methods used for detecting occlusal modifications:

3- Yurkstas Technique

Use of a commercially available U shaped metal occlusal template that

is slightly convex on the lower surface. This template is often an aid

in detecting minor deviations in the occlusal scheme

Methods used for detecting occlusal modifications:

4- Boucher Technique

The interferences are removed by movement of the maxillary porcelain teeth over

the mandibular stone teeth.

Pre-maturities are identified and removed by grinding the natural teeth. The

procedure is repeated for right and lateral excursions until a harmonious

balanced occlusion is established.

METHODS USED FOR A HARMONIES BALANCED OCCLUSION:

Many techniques have been used to achieve a harmonious balanced occlusion of a

complete maxillary denture opposing natural teeth. They basically fall into two

categories:

1. Dynamic equilibration of occlusion by the use of a functionally generating

path.

2. Static equilibration of occlusion with an adjustable articulator.

MATERIALS FOR ARTIFICIAL POSTERIOR TEETH:

Acrylic

resin.

Porcelain.Gold Cast metal

Acrylic resin with amalgam stops.

ESTHETICS OF MAXILLARY SINGLE DENTURE

The fixed positions of mandibular teeth limit the esthetic position of

maxillary anterior teeth. How to solve the esthetic problem?

To create enough horizontal overlap to allow freedom to balance in

eccentric movements.

Or to steeping the posterior cusp angles so that the posterior teeth

will disocclude the anterior teeth during eccentric movement.

MANDIBULAR SINGLE DENTURE:

The prognosis of a mandibular single denture against natural teeth is

less favorable than when the full upper denture is opposed by natural

lower teeth . It would be difficult to classify this case as clinically

successful.

This is due to:

1- Excessive resorption of lower ridge due to greater stresses per unit

area delivered to the mandibular ridge by the natural teeth.

2- Occlusal problems: The presence of natural teeth will present

difficulties in controlling the occlusal scheme.

MANDIBULAR SINGLE DENTURE:

3- Minimal denture foundation area

4- Fracture.

5- Tooth wear.

6- Tissue abuse.

MANDIBULAR SINGLE DENTURE:

The alternative line of treatment plan for such patient could be either:

1- Extraction of remaining teeth and complete upper and lower

denture are constructed.

MANDIBULAR SINGLE DENTURE:

Options other than extraction of maxillary dentition For Preservation of the Residual Alveolar

Ridge

1. Maximize denture base coverage

2. Minimized occlusal forces

3. Preprosthetic surgery

4. Retention of key roots

5. Use of osseointegrated implants

6. Temporary soft liners replaced on a regular basis

7. Permanent soft liners

COMBINATION SYNDROME AND ASSOCIATED CHANGES

(Kelly’s Syndrome)

A Combination Syndrome by Kelly (1972): destructive problems, that

may be encountered as a result of long term use of a mandibular

distal extension partial denture against a complete maxillary denture.

COMBINATION SYNDROME AND ASSOCIATED CHANGES

(Kelly’s Syndrome)

This syndrome consists of:

1. Loss of bone from the maxillary anterior edentulous ridge.

2. Down growth of the maxillary tuberosities .

COMBINATION SYNDROME AND ASSOCIATED CHANGES

(Kelly’s Syndrome)

This syndrome consists of:

3. Papillary hyperplasia of the tissues of the hard palate.

4. Extrusion of the lower anterior teeth and,

COMBINATION SYNDROME AND ASSOCIATED CHANGES

(Kelly’s Syndrome)

This syndrome consists of:

5. Loss of bone beneath the removable partial denture bases.

COMBINATION SYNDROME AND ASSOCIATED CHANGES

(Kelly’s Syndrome)

It usually has six associated changes:

1. Loss of vertical dimension of occlusion.

2. Occlusal plane discrepancy.

COMBINATION SYNDROME AND ASSOCIATED CHANGES

(Kelly’s Syndrome)

It usually has six associated changes:

3. Anterior spatial resorption of the mandible.

4. Development of epulis fissuratum .

5. Poor adaptation of the prosthesis

6. Periodontal changes.

COMBINATION SYNDROME AND ASSOCIATED CHANGES

(Kelly’s Syndrome)

The Combination Syndrome is a result of three main factors:

1. The great magnitude of forces involved from lower anterior teeth.

2. The unsuitability of the denture foundation to resist them

3. The particularly unfavorable occlusal relationship

Sincerely :

Dr. Hussein A. Hady Hussein