Overdentures are a useful treatment option in many clinical situations. A simple complete lower overdenture which encloses the roots of two root-treated canines has been shown above (Fig. 12.51). Cases can be more complicated than this. The reduction in the crowns of the teeth may have occurred due to tooth wear from a combination of erosion and attrition. In the elderly, where such tooth reduction has occurred, root canal treatment may not be necessary. The removal of the roots will not benefit the patient and the overdenture is the best form of treatment. Less common situations, such as partial anodontia, cleft palate or loss of tooth crown substance in dentinogenesis imperfecta, may also require restoration using overdentures. The distinction between an onlay and an overdenture is not clear-cut and a potentially difficult partial denture treatment, such as the restoration of a free end saddle, may be helped by the coverage of a canine or molar tooth with a reduced crown rather than a more involved crown restoration. In the case illustrated in Figure 12.53, an elderly patient has severe tooth surface loss. The aetiology of this wear must be diagnosed before treatment is commenced. For instance, is this wear a result of parafunction or erosion from the consumption of acidic drinks? The remaining dentition has been restored and a definitive overdenture placed.

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R.R Dental College And Hospital
DEPARTMENT OF PROSTHODONTICS
AND CROWN & BRIDGES
TOPIC : OVERDENTURE
SUBMITTED BY : SHAHEEN PARVEEN
( 4th Year )

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OVERDENTURE
CONTENT
1. Introduction
2. Rationale/ purpose
3. History
4. Classification
5. Indications and Contraindications
6. Advantages and Disadvantages

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7. Technique / Procedure
8. Retention of overdenture
9. Summary
10. Reference
INTRODUCTION
The dental profession has expanded the preventive dentistry
concepts into prosthodontics by treatment with overdenture.
The drawbacks of conventional complete dentures can be
masked by the use of overdentures, which dictates the
preservation of tooth structure or placement of implants.
Tooth-supported overdentures alleviate some of the

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consequences of conventional complete dentures like:
 Residual ridge resorption
 Loss of occlusal stability.
 Undermined aesthetic appearance.
 Compromised masticatory appearance.
Hence, it is regarded as a ‘preventive’ therapy. The treatment
involves preservation of teeth (usually canines) on either side of
the arch and extraction of all other teeth. abutments are restored
to good periodontal health, treated endodontically and coronal
portion is reduced to the desired level depending on the type of
overdenture (usually 2-3 mm above gingival margin). A
conventional complete denture is then fabricated over these
abutments. Attachments can be used on the abutments to retain
the denture.
Synonyms
1.tooth supported dentures
2. overlay dentures
3. onlay dentures
4.telescoped dentures
5.hybrid dentures

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6. biologic dentures
7.coping prosthesis
8.superimposed dentures.
RATIONALE / PURPOSE
Maintenance of health - Most important aspect is the
maintenance of the health of the underlying tooth structure.
abutment teeth must first be evaluated for their periodontal
condition. increased crown-to- root ratio, extensive bone loss,
and mobility do not necessarily negate the use of a tooth for an
abutment.

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Reduction in crown to root ratio -Shortening the natural tooth
changes the crown root ratio.
This reduces the lateral stresses.
It also reduces lever action on the tooth.
The load is now in a more occlusal direction.
The complete denture resting on these shortened teeth exerts
largely vertical forces.
The roots of the tooth offers the best available support for
occlusal forces.
Rate of bone resorption is prevented.

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IMPLANT SUPPORTED OVERDENTURE

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TOOTH SUPPORTED OVERDENTURE
DEFINITION
It is defined as, “A dental prosthesis that replaces the lost or
missing natural dentition and associated structures of the maxilla
and/or mandible and receives partial support and sta- bility from
one or more modified natural teeth”
Or

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“Any removable dental prosthesis that covers and rests on one
or more remaining natural teeth, the roots of natural teeth,
and/or dental implants; a dental prosthesis that covers and is
partially supported by natural teeth, natural tooth roots, and/or
dental implants also called overlay denture, overlay prosthesis,
superimposed prosthesis (GPT8).”
HISTORY
The idea of leaving roots of natural teeth to support an
overdenture is far from new.
1856 - Ledger had described a prosthesis resembling an
overdenture.
paper published by Atkinson (5 years later).
1861 there appeared to be an increasing awareness of the
value such roots might play in supporting a covering denture,

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1888 Evans had described a method of using roots actually to
retain restorations.
1896 Essig had prescribed a tele- scopic-like coping.
1909 - a great blow was delivered by William Hunter with his
so-called focal sepsis theory.
Rothman (1976) stated that Hunter’s comments gave dentistry
a black eye.
The reasons for retaining the roots were not specified.
Most of the retention systems that were developed between
the wars, and after the Second World War, provided support,
stability and retention.
CLASSIFICATION
Based on method of abutment preparation
1.Non-coping
With endodontic therapy
Without endodontic therapy
2.Coping
With endodontic therapy (short coping)

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Without endodontic therapy (long coping)
3.Attachments
Based on type of overdenture
1.Immediate over denture
2.Transitional over denture
3.Remote over denture
A) A tooth should be endodontically treated
B) The crown should be reduced to about 2-3mm
C) The entrance filled with amalgam

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BASED ON METHOD OF ABUTMENT PREPARATION
Noncoping abutmemts with endodontic treatment
Require endodontic therapy.
Abutment reduced to a coronal height of 2 to 3 mm.
Contoured to a convex or dome shaped surface.
Noncoping abutmemts without endodontic treatment
Sufficient interocclusal space present.
Indicated in patients with partial anodontia and severe attrition.
Coping abutments
A coping is a thin covering.
Give better protection against caries.
Cast metal copings with dome shaped surfaces.
Champer finish lines at the gingival margins are made and
cemented.
(1) Short cast copings
2 to 3mm long
Require endodontic treatment
Coping is attached by means of a post in the root canal

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A) The abutment teeth are endodontically treated and reduced in height
and a post space is created.
B) Dome - shaped cast metal copings 2-3 mm in height with a chamfer
finish line and a post are fabricated and cemented

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Canal obturated with gutta percha
(2) Long cast copings
5 to 8 mm long
Conservative reduction
Greater level of osseous support
Abutments with attachments
To increase retention, special retentive devices are attached to
the abutment
BASED ON TYPE OF OVERDENTURE
Immediate over denture
It’s constructed for insertion immediately after extraction of
natural teeth.
Transitional over denture
It is obtained by converting RPD into an over denture.
Remote over denture
It is constructed after the extraction of the teeth, endodontic
therapy, cast copings or any other procedures.

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INDICATIONS
 For better support and aesthetics in morphologically
compromised dental arches.
 Cleft palate cases.
 Dentures for patients with maxillofacial trauma.
 Patients with worn-out dentition.
 For congenital anomalies like microdontia, amelogenesis
imperfecta, dentinogenesis imperfecta and partial anodontia.
 Patients with abnormal jaw size and position where
orthognathic surgery is contraindicated. This treatment is
usually indicated for:
Group 1 : patients with few remaining teeth that may be healthy
or periodontally involved, with intact or grossly destroyed
crowns.
Group 2 : patients with severely compromised dentition.
Selective extraction should be carried out after a thorough
examination of the patient.

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CONTRAINDICATIONS
 High caries index and poor oral hygiene.
 When the abutments have a doubtful prognosis.
* When endodontic treatment is not possible.
 Failure to establish a sufficient zone of attached gingiva.
 Uncooperative, terminally ill, or senile patients.

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ADVANTAGES
 Preservation of the alveolar bone. Presence of the abutment
teeth reduce resorption.
 Preservation of the proprioception. Oral function and feeling
is improved.
 Improved support :because of the abutment teeth.
 Improved retention: Retention devices can be attached to the
abutment teeth when increased retention is needed.
 Less psychological trauma as patients are able to retain their
original teeth.
 Can be converted to a routine complete denture in case of
abutment failure.
 Used universally.

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DISADVANTAGES
 High risk of caries especially for the noncoping abutments.
 Risk of periodontal problems due to improper care by the
patient.
 High initial cost due to the castings, precision attachments,
preceding endodontics, periodontal and other therapies.
 Long bony undercuts are often found near the abutment teeth.
They cause many problems like :
* Tissue injury during insertion and removal.
* To avoid the undercuts the flanges are sometimes shortened
which can reduce the peripheral seal.
* Blockage of the undercuts results in a flange placed away
from the tissues.
This can result in esthetic problems due to the bulging of the lips.
Spaces between the tissues and the flange can also create a food
trap.
 Tooth arrangement is difficult in some cases because of the
reduced interocclusal distance.
 Frequent reviews are needed to verify the health of the

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supporting tissues of the overdenture abutments.
 More expensive than conventional dentures.
 Additional designing and laboratory work is needed.

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TECHNIQUE / PROCEDURE
Treatment sequence for the overdenture patient
1. Examination, diagnosis and treatment planning. This includes
oral hygiene and periodontal assessment, selection of abutment
teeth, patient education and motivation, and oral hygiene
counseling.
2. Referral for opinion from other specialists and completion of
prerequisite treatment
*Prerequisite oral surgery
*Prerequisite periodontics
*Prerequisite endodontics
3. Preparation and/ or restoration of abutment teeth and fluoride
therapy.
4. Impression and fabrication of copings and cast metal bases.
5. Impression and construction of overdenture.
6. Fixing of attachments (when indicated).
7. Delivery of overdenture and oral hygiene counseling.
8. Periodic recall with assessment of overdenture and abutment
status.

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EXAMINATION & DIAGNOSIS
Medical history :-
Heart disease, Hepatitis, AIDS, Psychiatric disorders etc.
Dental history :-
Much useful information
They are the following:
1. Why did the patient lose teeth?
2. What was the success or failure of earlier prostheses?
3. What did the patient expect from previous prostheses?
4. Is the patient presently wearing a denture?
5. Is there any history of cranio- mandibular disorders?
6. Are there any home care difficulties?

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EXAMINATION
Examination of oral cavity
(1) Visual examination
- General appearance.
- Facial asymmetry.
- Lip support
- Swellings or charge of colour of the
soft tissues.
- The Size and colour of the tongue..
- The slate of Ihe periodontal structures.
- The stale of the remaining dentition including the number,
distribution,angulation and relationships of the remaining
abutments.
- The vertical and buccolingual space available for denture
construction.
- The contours of the edentulous ridges and denture bearing
areas.

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(2) Digital examination:
- palpation of any swollen areas, together with all the edentulous
and denture bearing areas
- Probing depths Should be measured and mobility of the teeth
Individual teeth should be checked for caries, the margins of
existing restorations assessed, temporomandibular joint should
be palpated during opening, closing and lateral movements.
(3) Radiographic examinations:
Extra-oral and panoramic techniques such as
- Orthopantomograph
- Intra-oral radiographs
- Ct scan
- Scanora technique

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SELECTION OF ABUTMENT TEETH
It is concerned with the selection of teeth as overdenture
abutments.
Factors influencing the abutment teeth selection:
Periodontal status
Endodontic consideration
Location
Cost
Number
Space
Mobility
1. The periodontal status
o minimum mobility.
o have acceptable bone support,5-7mm.
o amenable to periodontal therapy.

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2. Acceptability of the tooth or teeth for endodontic treatment
a)inter-occlusal distance.
b) the crown-root ratio .
3. The number and position of the teeth in the arch:
Two teeth in each quadrant (canine or first premolar &a 2nd
molar in each quadrant)
The tripod is the next most favourable form.
two teeth in each arch .6
one tooth in one arch.
Periodontal treatment include:
Initial therapy
Surgical therapy
-root planning with direct visual access.
-surgical reduction of periodontal pockets by gingivectomy
and/or flap procedure.
-surgical crown lengthening.
-Widening of the attached gingiva through mucogingival
surgery.

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TOOTH PREPARATION
1-Simple Tooth Modification and Reduction
teeth are merely reshaped to eliminate undercuts
reduced in vertical height
Indication:
1-good oral hygiene with a low caries index
2-vital pulps must be receded sufficiently 3-partially anadontic
patient
4-severe abrasion of teeth
5-sufficient interocclusal distance
2-Tooth Reduction and Cast Coping:
•minimum reduction in the crown: root ratio
• A cast coping are made after reducing the teeth to prevent
sensitivity or as caries control Indicated when the teeth have :

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1 – Adequate bony support
2 – Good periodontal prognosis
3 – Adequate interocclusal distance
3-Endodontic Therapy and Amalgam Plug:
reduced (1-2mm)gingival level
endodontic therapy
4-Endodontic Therapy and Cast Coping:
• shallow dome shape with the margin slightly supragingival
• recurrent decay on the exposed dentin when there is a history
of carious involvement.
• short post
5-Endodontic therapy with cast coping utilizing some form of
attachment:
• patients with a favourable prognosis

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a- low caries index
b- proper home care
c- good periodontal health
d- Adequate bony support
e- Available inter-ridge distance
6-Endodontic treated tooth with prefabricated retentive
element:
simple and inexpensive
temporary fixation of overdentures
spherical retentive element attached to a threaded post
(Dalbo-Rotex system)
7- The telescopic overdenture:
• endodontically treated, reduced slightly
• smoothed and polished.

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RETENTION OF AN OVERDENTURE
- In case of large well formed ridges, overdentures may be
constructed with or without retentive devices.
- However, if increased retention is required, they may be
constructed with embedded retentive devices.
- Types of retentive devices used :
1. Precision attachments
i. Stud attachments
ii. Bar and clip mechanisms
2. Magnets
ATTACHMENTS
- Many overdentures are secured to abutments using attachments.
- There are tiny devices with a male and female portion.
- One part is joined to coping and the other to the overdenture.
- To use attachments, patient should have :
①Good bone support.
②Adequate interocclusal clearance.

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INDICATION :
1.Low caries index
2.Improved periodontal health
3.Good oral hygiene
4.Greater bone support
DISADVANTAGES :
1.More expensive
2.Requires more time to construct
3.Difficult to correct in case of failure.
STUD ATTACHMENTS :
- Stud attachment further classified into :
①Extraradicular attachments
②Intraradicular attachments

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Extraradicular attachments =>
 Male element is fixed to the abutment and projects from the
root surface of the preparation.
 Female component is attached to the denture.
 Attachment of male component to the female component
provides the retention.
 The male parts are available as :-
(a) Prefabricated metal post - cemented directly to the root.
(b) Prefabricated resin patterns - which is cast and cemented to
the root.
 The female component is also termed as ‘retentive anchor’
and it is in form of ‘O’-ring or matrix.
 Examples: ORS-OD, Ceka.
Intraradicular attachments
=>
 Male element forms part
of the denture base and
engages a specially produced

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depression within the root
contour.
 Indicated in situations of
reduced interocclusal spaces.
 Examples: Logic and Zest
attachments.
BAR AND CLIP ATTACHMENTS :
- The typical bar attachment consist of a bar connecting two or
more abutment. eg., a bar joining two canine copings.
Intraradicular attachment.
1) male component 2)
female comp. 3) denture 4)
abutment tooth

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A) Single sleeve bar B) Multiple bars C) Rigid bars D) Dolder bar E) Hader bar
F) Round Ackermann bar

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A)Extraradicular attachment -male part with female (o ring) attachment
B)Extraradicular attachment -male part with female matrix (dalla bona)
attachment

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(A) Extraradicular - Ceka attachment.(B)Guttapercha is removed with Peeso reamer. (C)
Sequential drilling is performed. (D) The final drill should correspond to the shape and size of
attachment. (E) Prepared post space. (F) Male component housing is cemented on abutment.
(G) Male component is attached to housing. (H) Female component with housing is positioned
on male component prior to attaching it to denture. (I) Female component attached to denture
with autopolymerizing acrylic.

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(A) ORS-OD system (1) Housing for O-ring, (2) O-rings. (3)
plastic castable stud attachment and (4) lab analogue for stud.
Zest attachment 1)male component 2)female component

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Function
1. Splinting of the abutments.
2. Allows rotational movement allowing denture to take more
support from the ridges.
3. Provides tge regular functions of retention and support like
the earlier mentioned stud attachments.
Classification
- The bar attachment can also function like a rigid stud when
designed in a certain way. These are known as bar units.
- Thus there are two types of bar attachments :
(a) Bar joints - permits rotational movements.
(b) Bar unit - Rigid fixation. Permits no movements.

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MAGNETS
- Special magnets are available which can be attached to the
overdenture abutments.
- The magnets attract small metal plates embedded in the
overdenture.
- The magnets generates forces of attraction sufficient to provide
retention to the overdenture.
Magnetic attachment -
1) Denture retention element
2) keeper
A lateral dislodging force on
a rigid stud attachment (left)
will transfer all load to the
tooth. In a magnetic
attachment (right) sliding
mechanism prevents transfer of stresses to abutment.

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IMPRESSION FOR THE DENTURE
Follows the same technique that is used in constructing a
conventional complete denture.
• PRELIMINARY IMPRESSION
• BORDER MOLDING
• FINAL IMPRESSION
(1) Record bases and occlusal rims
recording maxillo mandibular relations
• A face bow transfer is used to relate the maxillary cast to the
articulator.

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• Jaw relations and arrangement of teeth for phonetics are
verified at the time of try in.
(2) Tooth selection
Artificial teeth placed over the abutment teeth should be acrylic
resin. When teeth in opposing arch have
i) Gold occlusal surfaces occlusal surfaces of artificial teeth
should be either gold or acrylic” resin, preferably gold.
ii) Restored with porcelain - Porcelain artificial teeth are
preferred.
iii) Natural teeth - Gold occlusals are preferred, otherwise
acrylic
(3) Trying the denture
• Verify jaw relation records
• Make eccentric jaw relation records and adjust the artículator.

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• Assure esthetic acceptability by the patient.
• Verify phonetic acceptability.
(4) Laboratory procedures
• CONTOUR THE WAX
• FLASK THE DENTURE
• ELIMINATE THE WAX .
• PRAPARE RESIN
• PACKING
• RELIEF FOR MARGINAL GINGIVA
(5) Denture insertion
• Review instruction in denture use and care.
• use pressure disclosing paste to locate contacts between female
and male members.
• Evaluate the tissue side of denture base and borders for
pressure areas and over extensions.
• Perfect the occlusion by remounting and selective grinding.
• Recall the patient.

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(6) Delivery and post insertion care.

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SUMMARY
The overdenture is a very valuable option in the treatment of a
patient with multiple missing teeth. Unfortunately, it is not used
to its full potential or is frequently misused. Careful case
selection and abutment preparation as well as periodic recall is
the key to a successful overdenture rehabilitation. The patient
should be made aware of the increased cost and the greater
number of appointments that may be required for the successful
completion of the overdenture. Emphasis should also be placed
on rigorous oral hygiene protocol. The benefits of a successful
overdenture far outweighs its increased cost and difficulty of
construction.
Emphasis must be placed on proper patient selection, patient
motivation, basic prosthodontic principles, and a detailed
program of home- care instruction and frequent recall. In most
cases routine home-care procedures may not be sufficient. Floss,
perio aids, small brushes, rubber tips, and so on must be utilized
judiciously to guarantee that all plaque accumulation is removed
from the tooth surface and sulcus. The dentist and patient should
review the various techniques together to determine the best

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approach. What one patient is capable of doing with his or her
coordination may not be possible with the next patient. For this
reason. each home-care program is set up specifically for each
patient. At times a home-care aid may be developed specifically
for a particular patient The importance of adequate home care
cannot be overemphasized.
The overdenture is an outstanding mode of treatment. The teeth
that are used for support and retention are of critical importance
for the maintenance of health. A breakdown in their structure or
a breakdown in their periodontal support immediately negates
an overdenture concept. If we are to succeed, we must control
the factors that jeopardize success. If we control periodontal
disease by periodontal therapy and proper home care, if we
control caries by home care and chemical protection, and if we
select our patients wisely, we can he relatively assured of a
successful outcome for many years with overdenture patients.

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REFERENCE
1.Sarandha D.L,Textbook of complete denture prosthesis,
overdenture;jaypee publication (2007):149-154
2.Deepak Nallaswamy Veeraiyan,Text book of prosthodontics,
2nd edition(2017):331-334
3.John J.Manappallil, Complete Denture Prosthodontics,
overdentures:2nd edition(2011):347-356
4.Harold W. Preiskel ,Overdenture Made easy, A guide to
implant and root supported prostheses, treatment planning;1st
edition(1996);21-43
5.V Rangarajan |TV Padmanabhan, Textbook of prosthodontics ,
Overdentures 2nd editon( 2019)711-723
6.Sheldon Winkler, Overdentures Essential of complete denture
prosthodontics, (1994) 2nd edition :384-402
7. Varun Kumar,suyashree gupta, yogeshwari Krishna,
International Journal of oral health dentistry,Tooth sopported
overdenture ,July-september, (2018);4(3):184-187
8.Zarb - Bolender ( Ecker. Jacob. Fenton.. Stern),Prosthodontic
Treatment For Edentulous patients ,12th edition ,(2003),160-176