Dr. Mahmoud Ramadan

Rem. Prosthodontics502

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Dr. Mahmoud Ramadan

Overlay Denture*Advantages-:

1-Superior method of treatment of certain cases as congenital defects. E.g. (cleft palate, class III pt's& pt's have few remaining teeth).

2-Simplicity of construction: as those for conventional complete denture.3-Ease of maintenance: (repairs, alteration or refitting of over-denture)

as those for conventional complete denture.4 ↑-stability as in fixed& complete dentures.

5-↑ retention because, of ↑ stability of over-denture.6-↑ esthetics: due to restoring bony defects & selection of teeth freely.

7-Open (roofless) palate is possible when anterior& posterior are saved.8-Reasonable cost: ↓ than fixed partial denture.

9-familiar procedure: no special training should be required.10-Ease in making measurements: the vertical dimension of occlusion

maintained with high degree of accuracy – stabilization of the recording bases.

11-Ideal occlusion: the occlusion is acceptable esthetically.12-Excellent pt. acceptance: because, loss of all teeth at an advanced age,

more traumatic to the pt.13 ↓-trauma to supporting structure: ↓ resorption of alveolar ridge.

14-Stabilisation& support of existing structures: vertical dimension of occlusion is maintained and lip& face support is maintained.

15-Minimal adjustment: because, of ↑ stability& support.16-Possibility of using attachments( ↑ retention )& soft liners( when it is

difficult to maintain a seal ).17-Transitional (training) denture: for preparing to receive complete

denture.18-Conversion to complete denture: loss of one or all retainable teeth

corrected by relining& rebasing.19-Reversibility.

20-Ease of cleaning: being removable →easier to clean than fixed partial denture.

*Disadvantages-:

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Dr. Mahmoud Ramadan

1-↑ expensive than conventional complete denture(endo- perio- surgery).

2-Bulker than fixed partial denture or removable partial denture.3-Some prefer fixed partial dentures& don't like removable dentures.

4-Caries& periodontal diseases can progress in pt's with↓oral hygiene.

*Indications-: 1 -Presence of few remaining teeth.

2 -Pt's with only one root or tooth remaining.3 -Pt's with poor prognosis for complete dentures.

4 -Pt's with class II & IV Angle classification.5 -Pt's with abnormal jaw size or bony defects.

6 -Pt's with congenital defects (cleft palate or microdontia).7 ↓ -periodontal health of teeth (↓ crown-root ratio ↓ mobility).

*Contraindications-:1 -Poor oral hygiene.

2 -Low inter-arch space (can't accept the denture& the abutments).3 -Grade II mobility of teeth.

Examination, Diagnosis, Treatment planning& Prognosis

A)History & Records-:

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Dr. Mahmoud Ramadan

[I ] Medical history-:→ + ) ve( correlation between emotional state& denture problems.

→ Debilitating medical or psychiatric disorders.→ Pt. ability to maintain an adequate level of oral hygiene.

[II ] Dental history-:→ Past dental history gives information about previous experiences

which may influence his attitude, motivation& expectation.→ Why did the pt. loose teeth& what difficulties did he have with

replacements?→ Pt. should be formed about expectations within treatment capabilities

to avoid disappointment.→ Pt. with acceptable oral hygiene have much better over-denture

prognosis than those of bad oral hygiene.

[III ] Pretreatment records-:1 -Accurate diagnostic casts mounted in a suitable articulator which

supply information about the pt.& selection of the abutments.2 -Color transparences or photographs .

3 -Cephalometric radiographs.

B)Examination-:♥ Visual& Digital Examination-:

a- Visual Examination-:→ Lips, buccal Mucosal, gingiva, floor of the mouth, hard& soft palate

should be examined.→ Possible pathologic changes should be evaluated.

→ Evaluation the response of supporting tissues to existing prosthesis, such as inflammation or hyper plastic tissue.

b- Digital Examination-:→ Exostosis, sharp mylohyoid ridges, displaceable tuberosity tissue,

displaceable tissues on the residual ridges, tissue undercut areas in need for surgical correction.

♥ Dental Examination-:

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Dr. Mahmoud Ramadan

1 -Carious lesions& defective restorations.2 -Vitality tests.

3 -Missing teeth .4 -Condition of replacements.

5 -Occlusion.6 -Adequate denture space.

7 -Clenching or Bruxism.8 -Abnormal tongue or lip habit.

9 -Oral hygiene status.10 -Pt. denture cleaning methods.

♥ Periodontal Examination-:

→ Diagnosis of-:1 -Signs& symptoms of chronic periodontal disease.

2 -Generalized bone loss.3 -Increased periodontal pocket depth.

4 -Hyper-mobility.5 -Crevicular& pocket depths as well as furcation should be probed.

6 -Teeth with horizontal& Vertical displacement are poor choice.→ It is essential to evaluate the pt. oral hygiene in relation to the

periodontal status.→ Maintaining an adequate oral hygiene is important in achieving a

reasonable service life for the overlay denture.

♥ Radiographic Examination-:→ Individual periapical films supplemented by a panoramic radiograph

should be adequate. Also we should observe-:1 -Retained roots.2 -Impacted teeth.

3 -Crown-Root ratio.4 -Carious lesions.

5 -Status of previous endodontic treatment.6 -Radiolucent& radiopaque lesions of the jaw.

7 -Status of periodontium.

C) Treatment Planning-:

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Dr. Mahmoud Ramadan

* Indications for Fixed Partial Denture -: 1 -Properly distributed& healthy teeth to serve as abutments.

2 -Teeth have suitable crown-root ratio after radiographs, diagnostic cast& oral examinations.

* Indications for Removable P a rtial Denture -: 1 -Distal extension situations.

2 -After recent extraction.3 -Long edentulous span.

4 -Need for bilateral bracing.5 -Esthetics in anterior region.

6 -Excessive loss of residual bone.

* Indications for Removable Complete Denture-:1 -Uncooperative& disinterested pt.

2 -No retainable teeth are present.

*Indications for Overlay Denture-:1 -4 or fewer retainable teeth are present in an arch.

2 -Pt. loose teeth in one arch& the other remain dentulous.3 -Unfavorable tongue position or improper muscle attachment.

4 -Any situation in which stability& retention would be a very serious problem with complete denture.

♥ Types of Overdenture-:1 (Immediate Overdenture-:

→ Constructed for insertion immediately after removal of some natural teeth.

→ Used when pt. has many hopeless teeth.→ The abutment teeth are selected, treated and then, Overdenture is

inserted.→ This type is modified as required& can be worn for several years.

2 (Transitional Overdenture-:→ Obtained by converting an existing Removable Partial Denture to

Overdenture status.

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Dr. Mahmoud Ramadan

3 (Remote Overdenture-:→ Constructed for insertion at time remote from removal of hopeless

natural teeth.→ Complete or Partial Overdentures with metal or acrylic bases can be

fabricated.

♥ Abutment Selection-:→ The abutments should be evaluated from the view of points-:

a) Periodontal Status-: *Teeth must have acceptable state of periodontal health prior to

completion of the Overdenture.→ Basis for selection-:

1 -Acceptable state of periodontal health.2 -Use teeth that less than ideal.3 -Teeth with minimal mobility.

4 -Adequate bone support.5 -Accept periodontal treatment.

6 -Good crown-root ratio.b) Caries activity-:

→ Teeth with minimal or no caries involvement should be selected for abutments.

→ Carious teeth can be selected after successful restorative procedure.→ Caries in unprotected abutments can lead to failure of the

restoration.

c) Potential for Endodontic treatment-: *Recommended for Overdenture abutments. *It's advantages overcome it's disadvantages.

→ Successful Endodontic treatment contributes to-:1 -Esthetics: by allowing sufficient reduction of the abutment tooth.

2 -Crown-root ratio: improved by crown reduction.3 -Permits using of: tilted or malposed or hemi-sectioned teeth as

abutments for Overdenture.

d) Positional consideration-:→ Overdentures should be considered with 4 or fewer retainable teeth

(which have less than ideal periodontal support).

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Dr. Mahmoud Ramadan

*Depending on distribution-:♥ 4 abutments in one arch -:

→ Represent an ideal stress distribution. E.g. (2 Canines& 2 second premolars).

→ Factors affecting support in Overdenture-:1 -Number of the abutments.

2 -Distribution of the abutments.3 -Position of the abutments.

♥ 3 abutments in one arch -: → 2 abutments are in one side of the arch& one is on the other side, will

give unbalanced support.→ 2 canines& one central incisor (tripod), will give better distribution.

♥ 2 abutments in one arch -: → Canines& premolars are selected more than any other type of teeth.

Because, they are-:1 -Amenable to endodontic treatment.

2 -Adequate periodontal attachment area.3 -Strategic positions in the arch.

→ The 2 abutments should be situated bilaterally for optimum support.→ Anterior positioning of the canines minimize the soft tissue loading in

anterior arch.

♥ Good results gained when abutments aren't approximating-:1 -Canine& approximating premolar don't give much more support

than one abutment.2 -Approximating abutments are difficult to clean.

3 -Approximating abutments make positioning of teeth in Overdenture more difficult.

e) Occlusal consideration-:→ It is essential to consider occlusion in selecting abutments for

Overdenture-:1 -If an Overdenture is opposed by Removable Complete or Partial

Denture the forces will be less than if the Overdenture is opposed by intact natural dentition.

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Dr. Mahmoud Ramadan

2 -Abutments for Overdentures opposed by a natural dentition should be selected to reflected the high need for support& stability.

D)Prognosis-:1 -Accurate examination& diagnosis affect prognosis of Overdenture.

2 -Oral hygiene level of the pt.3 -Clinical& laboratory procedures.

4 -Post-insertion service& maintenance.

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