• Extraction of teeth is followed by continuous ridge
resorption and poor denture foundation
• Loss of periodontal receptors responsible for proper
masticatory function and accurate jaw movements.
• Retention of few remaining teeth will preserve
alveolar bone and preserve periodontal receptors.
A removable partial denture or complete denture
that covers & rests on one or more remaining
natural teeth, the roots of natural teeth, &/or
•Tooth supported denture
•Overlay denture/ Onlay denture/ Inlay denture
• Telescopic denture
• Superimposed prosthesis
• Hybrid denture
o The roots of the tooth offers the best available
support for occlusal forces.
o Accelerated rate of bone resorption is prevented.
o It increases pt’s manipulative skills in
handling the denture. (periodontal membrane
is preserved ,thus proprioceptive impulses, part of
myo-facial complex are retained.)
Occlusal forces are transmitted on
oblique fibres and dissipated as tension
resulting in osteoblastic respose
Heartwell 4th Ed page 503
• LEDGER (1856)prescribed a prosthesis
resembling an over denture. His restorations
were referred to as plates covering fangs
• EVANS(1888) described a method for using
roots to retain restorations after intentional
devitalisation of the roots.
• ESSIG(1896) described a telescopic‐like
• 1906–WILLIAM HUNTER put forward his focal
sepsis theory and this dealt a great blow to the
overdenture mode of treatment.
The main point of contention was that the
exposed roots act as foci of infection.
• 1916‐PEESO was employing removable
telescopic crowns. Later on, the bar type of
construction was developed.
• MILLER (1958 ) published his classic article
where the retention of previously unusable
teeth and their advantageous use in
overdenture treatment was explained as a
basic tenet in management.
• Prieskal(1968)described various
commercially available overdenture
Preiskel HW. Prefabricated attachments for compete overlay dentures.
Br Dent J 1967;123:161.
• Ridge preservation
• Superior patients acceptance
• Open palate possible
• Definitive vertical stop for denture base
• Support, stability and retention are improved
• Less trauma to supporting tissues
• Fever post insertion problems than conventional
• Conversion to complete denture
• Increased biting force (Pacer FJ, Bowman DC. Occlusal force
discrimination bydenture patients. J Prosthet Dent 1975;33:602–9)
• Physiological Advantage
Patient with badly worn teeth.
Pt. with few natural remaining teeth.
Poor prognosis for routine complete denture.
Congenital or acquired intra oral defects.
Mandibular arch where loss of bone is more rapid
Edentulous maxilla opposing intact mandibular
Post traumatic or post surgical cases.
Severe attrition and loss of vertical dimension.
Cleft palate causing large free way space.
Tooth wear cases
High caries index.
Poor oral hygiene.
Poor prognosis of abutment.
Reduced inter-arch space.
Sufficient attached gingiva not present.
Where endo and perio treatment can not be
Grade III mobility
ACCORDING TO METHOD OF
Tooth supported Implant supported
Non Coping Coping Attachments
BASED ON TYPE OF OVER DENTURE
(Brewer and Morrow)
Immediate over denture
• Constructed prior to preparation & ready for
insertion after preparation & reduction
• It enhances patients ability and adaptability
to wear dentures
Interim over denture
• Used for patients in transition or preparation
phase until permanent overdenture
• Patient old partial denture can be modified &
used by extending the denture and add new
artificial teeth using self cure acrylic resin
Remote or Definitive over denture
• Conventional complete over denture
constructed over one or more abutment teeth
• Could be made entirely of acrylic resin or in
conjunction with metal bases
NON COPING ABUTMENTS
Selected tooth abutments are reduced to a
coronal height of 2 to 3 mm. and then
contoured to a convex or dome shaped surface.
Most teeth required endodontic therapy and
in final step are prepared conservatively to
receive an amalgam or composite type
• Least expensive option
• More amenable to treatment, retreatment and
modification in contingency situations
• Greater degree of flexibility in formulating
ABUTMENTS WITH COPINGS
• Coping is a cover for the exposed tooth surface
• Cast metal coping with a dome shaped surface
and a chamber finish line at the gingival
margin are fabricated and cemented.
SHORT CAST COPINGS
• Short copings are 2-3 mm and normally
require endodontic therapy because the
required coronal root reduction would expose
Long cast coping
Long cast copings are normally 5-8 mm
long, conservative reduction of coronal tooth
structure is done.
The end result is long ellipsoidal shaped
coronal coping and a larger crown root ratio.
Consequently, long cast coping require a
greater level of osseous support.
Attachments are small precision devices.
Objective is to improve retention of denture base.
Most attachments are secured to abutment by a
Consists of two parts
Requirements for the Attachments
Patients should have a low caries index.
Perform proper home care
Sound periodontal health
Proper bone support
Disadvantages of attachments
Difficult to construct
Repair is difficult
Requires careful manipulation by the
patient, not recommended for mentally and
• Doesn’t allow movement of denture base
• Provide adequate retention
• May induce more torque on abutment
• Allows some control of movements
• Induces less torque on abutments
1. Stud attachment
simplest of all attachments
Consists of two parts
• The stud(male component) usually attached
to metal coping cemented over prepared
• Housing (female component) embedded in
the fitting surface of over denture
Extra radicular stud attachment
Male element projects from the root surface
The stud is attached to the metal coping
cemented over the prepared abutment, while the
housing is embedded in the fitting surface of
• Readily replace able male or female
attachments by unscrewing the worn unit.
• Male part consists of groove
• Female part (housing) consists of C shaped
ring which fits in deeper part of retaining
• Male part round with cementable titanium
• Female part in titanium alloy with
replaceable plastic part that is flexible and
compressible (split vertically into four
Other attachments of importance
Intra radicular stud attachment
The stud is attached to the fitting surface
of the denture and the housing is
incorporated in the abutment.
• Zest Anchor
Zest anchor system
• Female sleeve is cemented in post space made
within the root
• Male portion consists of nylon
• The attachments should be aligned to each
• Should be in line with the path of insertion
of the denture.
• A divergence of 10 degree can be tolerated
• Significant divergence of roots or implants
should be considered a contra indication for
• One stud attachment on either side of the arch
will suffice; the remaining roots can be covered
by simple copings.
• Increasing the number of attachments does not
necessarily increase retention; it may
contribute to improved stability, but leads to a
• Two stud attachments on adjacent roots are
unnecessary as it would complicate hygiene
measures and also weaken the denture base
o A bar contoured to connect abutment teeth
together, run parallel & overlie residual ridge
o Preformed metal or plastic.
The purpose of using bars are:
• Splinting of abutment teeth
• Retention and support of prosthetic appliance
o Spreads loading
o Soldered to copings
Plaque control difficult
• The bulk of bar and related structures raises
• Vertical and buccolingual space
requirements limit their applications.
• Bar attachments also demand more oral
hygiene maintenance from the patients.
o Rigid type
o No movement between bar and sleeve
o Transmits occlusal stresses totally to
o Thus Tooth born
o Allow some movement of rotational type
between bar and sleeve.
o Utilize support both from residual ridge
o Thus tooth tissue born
Bar attachments of importance
• Haden bar
• Dolber bar
• Baker clip
• Ackerman clip and CM clip
• King connector
o Detachable keeper element
• Made of stainless steel that is fixed to abutment
o Denture retention element
• Has paired, cylindrical Co- Sm magnets
axially magnetized and arranged with their
opposite poles adjacent
• Small, strong mini magnets
• One of poles cemented in the prepared cavity
in endodontically treated abutment and the
other attached to denture base.
PLANNING AND CASE
If you don’t know where you go,
you never get lost
Possibility of fixed or removable
• If the remaining teeth are capable of
supporting a fixed or removable prosthesis,
then that should be the primary mode of
• Extractions are to be avoided in a young
patient as far as possible, so overdenture do
play a major role in treating young patients
with mutilated dentition.
Factors influencing selection
of abutment teeth
• Periodontal status
• Endodontic considerations
Periodontal & Mobility status
• Ideally tooth should present minimal
mobility, have acceptable bone support and be
responsive to periodontal therapy.
• Circumferential band of attached gingiva is
an absolute necessity.
• Compromised teeth with good treatment
prognosis are suitable candidates even when
horizontal bone loss is present
• Slight tooth mobility with horizontal bone
loss is not contraindicated as decrease in C-
R ratio required for abutment preparation
Reduces the length of the lever arm
• Vertical bone loss particularly accompanied
by Class II or III mobility excludes tooth
• Ideal: Two teeth per quadrant (stress is
distributed over a rectangular area)
• Tripod is next most favorable form for
support and stability.
• Clinical experience recommends at least one
tooth per quadrant.
• Isolated teeth are preferred to several adjacent
teeth as inter dental areas are difficult to
clean and susceptible to gingivitis.
Robert M. Morrow, Colonel , Ret. USAFDC, Virginia, 1970
• Anterior mandibular ridge is most
vulnerable to time dependent RRR
• Canines and premolars are regarded as best
• In maxilla central incisors are ideal
as overdenture abutments( Protects
• Canines are next (Longest Root)
• Lateral incisors(widely spaced,
facilitating plaque control)
• Preserve teeth that are already
• Usually anterior teeth are preferred as they are
easier to prepare and economical too.
• Whenever pulpal recession to the extent of
calcification has occurred , endodontic
treatment usually can be avoided.
• Ettinger in 1990 showed that the most
common cause of abutment failure was vital
teeth developing periapical lesions as a result
of pulpal necrosis ( 53.8%).
According to Zarb 13th edition
• After 5-6years, about 10% of abutment teeth
supporting overdentures were lost
Periodontal disease 70%
Endo complications 5%
• Patient is motivated to maintain adequate
oral hygiene to prevent abutment loss.
• Patients must clean all exposed dentin and
use 0.4% stannous fluoride daily.
Thayer, H. H. Overdenture and the periodontium. DCNA 24:369-377, 1980.
FOLLOWING SEQUENCE OFT TREATMENT CAN BE USED AS A
GENERAL GUIDE BUT MAY NOT BE SPECIFICALLY APPLICABLE
TO ALL PATIENTS:
1. Construct an immediate treatment clasp less
denture. It replaces missing and hopelessly
involved teeth for esthetic reason and retain jaw
2. Remove hopeless teeth and insert the removable
3. During the healing period, institute the
periodontic and endodontic treatment.
• Remove sufficient tooth structure to provide
favorable root crown ratio.
• Reduce the crown length up to 2 mm above the
gingival crest or extend a chamber type margin
slightly beneath free gingival margin.
• Taper the preparation in occlusogingival
• Consequently optimal abutment preparation
is achieved that has following features:
• Dome shaped
• Chamfer finish line
The finished tooth with cast coping is male
member of denture. The female member is
part of denture base.
• As a cost containment method, use of cast
coping has been largely eclipsed by composite
and alloy restoration with or without
adjunctive inter radicular attachments
• Make an accurate impression
of the abutment and pour a
• Carve the wax pattern.
• Cast the coping
• Cement the polished coping to
• Instruct the pt. in home care
of abutment tooth.
IMPRESSION FOR THE DENTURE
• Follows the same technique that is used in constructing a
conventional complete denture.
• PRELIMINARY IMPRESSION
• BORDER MOLDING
• FINAL IMPRESSION
RECORD BASES AND OCCLUSAL RIMS
RECORDING MAXILLO MANDIBULAR RELATIONS
• A face bow transfer is used to relate the maxillary cast to the
• Jaw relations and arrangement of teeth for phonetics are
verified at the time of try in.
• 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,
TRYING THE DENTURE
• Verify jaw relation records
• Make eccentric jaw relation records and adjust the
• Assure esthetic acceptability by the patient.
• Verify phonetic acceptability.
• CONTOUR THE WAX
• FLASK THE DENTURE
• ELIMINATE THE WAX
• PRAPARE RESIN
• RELIEF FOR MARGINAL GINGIVA
• 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
• Perfect the occlusion by
remounting and selective
• Place pt. on recall system
Final try in
SUBMERGED VITAL ROOTS
Selected vital roots are selected and reduced to 2
mm. below the crestal bone and then covered by
Still in experimental stage.
The method is innovative attempt to obviate the
basic problems like caries, gingivitis,
Major post operative problems are: development of
dehiscences over retained roots and pulpal
The minimum acceptable standard of care for
the treatment of the edentulous mandible
should be the provision of interforaminal osseo-
integrated dental implants to support and
retain the complete lower denture.
Quintessence International, volume 34, Number 1, 2003
Why implant OD and not Full arch
Fixed Implant Prosthesis
• Lesser Implants
• Less cost
• Previous Denture wearer
• Denture is less complicated than Implant Fixed
• Overall esthetic objectives can be addressed and
achieved with greater ease
Inclusion Criteria for Implant
• PT. DESIRE FOR IMPLANT TREATMENT
• SYSTEMIC HEALTH STATUS, WHICH
PERMITS A MINOR SURGICAL
• SUFFICIENT BONE QUANTITY TO
ACCOMMODATE PRESCRIBED IMPLANT
• PT. WILLINGNESS AND ABILITY TO
MAINTAIN ORAL STATUS
Prosthodontic Treatment for edentulous Patients
Zarb 13th edition Pg 331
Exclusion Criteria for Implant
o RESIDUAL RIDGE DIMENTIONS DO NOT ACCOMMODATE
PREFFERED IMPLANT DIMENTIONS
o COMMUNICATION WITH PT. IS NOT POSSIBLE
o PT. HAS HISTORY OF SUBSTANCE ABUSE
o GENERAL HEALTH CONDITIONS PRECLUDEA MINOR
o LOCAL ANAESTHESIA WITH VASOCONSTRICTER IS
o IMMUNOSUPPRESIVE THERAPY, PROLONGED INTAKE
OF ANTIBIOTICS OR CORTICOSTEROIDS, OR BRITTLE
MEABOLIC DISEASE HISTORY
Prosthodontic Treatment for edentulous Patients
Zarb 13th edition Pg 331
FOR A PATIENT WITH IMLANT OVERDENTURE
Treatment Planning concerns for patient
with Implant supported Overdenture
• Number of Implants and their location
• Preferred denture retention devices- The Attachment
• 4- 6 Implants and infrequently connected
using a bar.
• Implant length preferably 10mm or longer.
• 2 un-splinted implants with a selected
attachment method (current & most frequent)
between canine and lateral incisor.
• 12 mm inter implant distance required
• When shorter implants are used more number of
implants can be placed
A healing period of 3-4 months for
mandibular implants and 6 months for
maxillary implants ( conventionally
loading) has been traditionally observed.
• Selection of a specific attachment for an implant
overdenture depends on the following;
• - Type of overdenture fabricated.
• - Location of implants on the ridge.
• - The condition of the residual alveolar ridge.
• - Dexterity of the patient.
• - Psychosocial needs of the patient.
• - Relative need for stability and retention.
• - Length of implant used.
As a general rule, more complicated and
sophisticated the attachment, more difficult it is to
repair and maintain.
• FEMALE PORTION -PROSTHESIS
• MALE PORTION –IMPLANTS
• Ball Attachments
• Bar & Clip Attachments
CM Bar & Rider/Ackermann Clips
Dolder Bar System
Häder Bar System/EDS System
• Over denture is an excellent viable treatment
• Emphasis must be placed on proper patient
selection, pt. motivation, basic prosthodontic
principle & detail program of home care
instruction & frequent recall.
• The overdenture is an out standing mode of
treatment. Breakdown in tooth structure or a
breakdown in their periodontal support
immediately negates an overdenture concept.
IF WE ARE TO SUCEED, WE MUST CONTROL THE
FACTORS THAT JEOPARADIZE SUCCESS.