Stress exerted against the teeth and their attachment apparatus by occlusal forces may be within the adaptive capacities of the tissues or else the tissues may not be capable of compensation and adaptation and the result is tissue destruction

1. STRESS
BREAKERS IN
RPD
Presented by:
Dr. Kumari
Kalpana
Pg 2nd year

2. C
O
N
T
E
N
T
S
Introduction
Definition
Types of stresses created on the abutment teeth
Philosophy of design
Classification
Attachments
Conclusion
References

3. INTRODUCTION
Stress exerted against the teeth and their
attachment apparatus by occlusal forces
may be within the adaptive capacities of
the tissues or else the tissues may not be
capable of compensation and adaptation
and the result is tissue destruction
3

4. • Various approaches are been made to distribute the stress or
forces acting on a partial denture between the soft tissue and
teeth one among them is stress breaker. The stress breaker is
suggested as a means to allow the base to move slightly with
less strain to the abutments
4

5. DEFINITIONS1
5
1. The Glossary of Prosthodontic Terms. J Prosthet Dent 2017 ;117(5S):e1-e105.

6. • STRESS BREAKER :a device or system that
relieves specific dental structures of part or all of
the occlusal forces and redirects those forces to
other load bearing structures or regions (GPT9)
6
The Glossary of Prosthodontic Terms. J Prosthet Dent 2017 ;117(5S):e1-e105.

7. • Attachment: A mechanical device
for the fixation, retention, and
stabilization of a prosthesis
• A retainer consisting of a metal
receptacle (matrix) and a closely
fitting part (patrix); the matrix is
usually contained within the
normal or expanded contours of
the crown on the abutment
tooth/dental implant and the
patrix is attached to a pontic or
the removable dental prosthesis
framework.
7

8. PRECISION ATTACHMENT :
• An interlocking device, one component of which is fixed to an
abutment or abutments, and the other is integrated into a removable
dental prosthesis in order to stabilize and/or retain it.
(GPT-9)
8

9. • Semiprecision Attachment: A laboratory
fabricated rigid metallic extension (patrix) of a fixed
or removable dental prosthesis that fits into a slot-type
keyway (matrix) in a cast restoration, allowing some
movement between the component
9

10. TYPES OF STRESSES CREATED ON THE
ABUTMENT TEETH
Vertical-vertical stress
results from a lack of
distal tooth support.
Lateral- lateral stress
results from a horizontal
movement of the denture
Oblique/anteroposterior-
anteroposterior stress is
a result of a combination
of the first two.
In general there are three types of stresses on the abutment
teeth

11. In all types of stress, the abutment becomes the fulcrum. To
control these stresses and to distribute them between mucosa
and the adjacent teeth requires a careful consideration of:
1] The condition of the teeth and mucosa
2] The impression techniques
3] The denture design
4] The distribution of stress between the mucosa and as
many supporting teeth as possible
11

12. PHILOSOPHY OF
DESIGN

13. • Philosophy of design
• Of the various philosophies relating to removable partial denture
design, none is backed by overwhelming scientific evidence. They
are the ideas of experienced dentists who have formulated rules for
the design of removable partial dentures.

14. • Nearly any removable partial denture design can be made to work
successfully if respect for the physiologic limits of the supporting
structures is observed.
• In partial denture design, the main concern is for prostheses that are
partially supported by teeth and partially supported by soft tissues

15. • Prostheses that are entirely supported by teeth are generally very
straight forward. Because these partial dentures derive all of their
support from the remaining teeth, a single impression may be used to
record the teeth and soft tissues.
• The length in design, then, lies primarily in Class I and Class II
arches and to some extent in Class IV arches. There is ongoing
controversy about the design requirements for free end or extension
base removable partial dentures (le, Class I, Class II, and long-span
Class IV applications).

16. The debate centers upon the amount of support that should be derived from
the edentulous ridge and that which should be derived from the remaining
teeth. These philosophies are based upon three approaches to force
distribution. These approaches may be described as follows:
1. Stress equalization
2. Physiologic basing
3. Broad stress distribution

17. Stress equalization
• The stress equalization approach to partial
denture design emphasize that the vertical
displaceability of a natural tooth is not as great
as that of the soft tissues covering the
edentulous ridge.

18. • Forces applied to a removable partial denture are
transmitted to the abutments. As a result, proponents
believe that rigid connections between denture bases
and direct retainers are damaging, and that stress
directors are essential to protect the abutments

19. • Stress directors may take several forms. The most commonly
used stress directors are simple hinges interposed between the
denture bases and the adjacent clasping assemblies.
• These hinges are designed to permit vertical movement of the
denture bases without causing undue loading of the
abutments. In addition, many of these devices can be adjusted
to control the amount of vertical travel that is permitted.

20. • Advantages
• Stress director designs usually call for minimal direct
retention because the denture bases operate more
independently than do those used in conventional removable
partial denture applications.
• Theoretically, stress directors minimize the tipping forces on
abutment teeth, thereby limiting bone resorption.

21. • Disadvantages
• Stress directors are comparatively fragile and their
incorporation into removable partial denture frameworks can
be costly.
• These devices require constant maintenance and may be
difficult or impossible to repair.

22. Physiologic basing
• Physiologic basing believe that there is a significant disparity between the
apical displaceability of teeth and the compressibility of the soft tissues.

23. • These practitioners believe that equalization can best be
accomplished by recording the anatomy of the edentulous ridge in its
functional form and ensuring that the associated denture base
accurately reflects this anatomy.
• It can be accomplished by depressing the mucosa during impression-
making procedures or by relining the denture base after it has been
constructed.

24. • This theory believe that denture bases
formed over compressed tissues will
show an increased ability to withstand
vertical forces. These practicioners also
recognize that the prosthetic teeth and
occlusal rests will be positioned above
the existing occlusal plane when the
prosthesis is not in function

25. • To permit vertical movement of the partial denture from its
rest position to its functioning position, the number of direct
retainers must be limited. Furthermore, these direct
retainers must be designed to provide minimal retention.

26. • Advantages Proponents of this theory believe that
denture base movement occurring as a result of soft
tissue compression and recovery exerts a
physiologically stimulating effect on the tissues of the
residual ridges.
• They also believe that this action promotes tissue
health and reduces the necessity for frequent relining
or rebasing procedures.

27. • The minimal retention requirements associated with physiologic
basing result in lightweight prostheses requiring minimal
maintenance and repair.
• The forgiving nature of retentive clasps (eg, combination clasps
with wrought-wire retentive arms) produces a significant reduction
in the forces transmitted to the abutment teeth. As a result,
advocates of this theory believe that abutments are retained for
longer periods.

28. Disadvantages
• Because the artificial teeth are slightly above the occlusal plane when the
denture is not in function, there will always be premature contacts
between the opposing teeth and the prosthesis during closure. This may be
somewhat annoying to the patient and may result in some discomfort.

29. • It is difficult to produce effective indirect retention because of the
vertical movement of the denture and the minimal retention provided
by the direct retainers.
• In addition to the foregoing factors, prostheses constructed in
accordance with physiologic basing principles are not well stabilized
against lateral forces. This is related to the minimal number of direct
retainers used in conjunction with these designs.

30. Broad stress distribution
• Advocates of broad stress distribution believe that trauma to the
remaining teeth and residual ridges can be prevented by distributing
forces over as many teeth and as much of the soft tissue area as
possible.

31. • This is accomplished by using additional rests and
clasp assemblies and by ensuring that the associated
denture bases provide broad coverage

32. • Advantages Proponents of this philosophy believe that forces transmitted
to the supporting teeth and residual ridges may be minimized by
distributing these forces over a greater number of teeth and a larger soft
tissue area.
• Advocates of this philosophy also believe that increased contact with the
remaining teeth and soft tissues minimizes the lateral forces on the
remaining structures. The use of multiple clasp assemblies is not intended
to increase retention.

33. • In addition to the advantages already listed, proponents of this
philosophy believe that the resultant prostheses are easier and less
expensive to construct.
• There are no moving parts, so there is less danger of fracture and
distortion. In addition, the rigid components minimize rotational
movements and provide excellent horizontal stabilization.

34. Disadvantages
• The increased coverage provided by such prostheses may not be
accepted by some patients.
• This coverage also may complicate oral hygiene. As a result,
preventive dental programs must be instituted and oral hygiene
must be carefully monitored.

35. SYNONYMS
FRICTIONAL ATTACHMENT PARALLEL ATTACHMENT
SLOTTED ATTACHMENT
KEY & KEYWAY
ATTACHMENT
INTERNAL
ATTACHMENT
35

36. EVOLUTION
36

37. • 1 Winders design Screw joint retention
• 2 Parr(1886) Extracoronal socket attachment
• 3 Stair Telescopic abutment restoration
• 4 Ash (1912) Split bar attachment system
37
1
2 3 4

38. • Late 19th century : Dr.Herman, ES Chayes“T shaped”
• Precision Attachment (1906)
• “H shaped”
• Chayes Attachment (1912)
• First attachment to be available in the general market
38

39. •Stress
management
39

40. FACTORS AFFECTING MAGNITUDE OF
STRESS TRANSMITTED
length of span
quantity and
quality of
supporting
ridge
clasp flexibility clasp design
length of clasp
material of
clasp
abutment tooth
surface
occlusal
harmony
40

41. INDICATIONS
Esthetics (clasp elimination)
Remaining root as abutment
Long span edentulous area
Stress equalization
Cross arch stabilization in reduced periodantal support cases
41

42. CONTRAINDICATIONS
Poor dental health
Desire & commitment of patient
Poor oral hygiene
Space constraint
42

43. ADVANTAGES
• Esthetics
• Retention incase of overdentures
• Stress director
• Cross arch stabilization
• Force closer to fulcrum thus less lateral
forces 43

44. DISADVANTAGES
• Cost
• Maintenance
• Repair
• Experience of dentist & lab
• Additional chair & lab time
44

45. • CLASSIFICATION OF ATTACHMENTS: Attachments are
classified in a number of ways:
• Bases on the method of fabrication and tolerance of fit:
• 1. Precision (prefabricated attachments)
• 2. Semi precision (custom made) attachments:

46. • Precision attachments are basically classified as follows
(Goodkind & Baker, 1976):
• Intracoronal
• Resilient
• Non-resilient
• Extracoronal
• Resilient
• Non-resilient

47. • Based primarily on the function of the attachments:
• 1. Rigid: Any attachment employing a mechanical locking
action with the use of clasps, lingual arms, springs, ball
and sockets etc. The removable partial denture is held
firmly in place and the abutment teeth are subjected to all
of the forces in the mouth at all times.
• 2. Passive: An attachment that provides a free movement
of the male when the abutment teeth are exposed to
excessive forces. Such a passive retention mechanism has
the effect of an automatic stress breaker.

48. • Mensor’s classification: An attachment classification based on shape, design and
primary area of utilization of attachment.

49. • Classification by Harold Prieskel:
• 1. Intracoronal attachments:
• A. Those whose retention is entirely frictional
• With adjustment potential: Constant insertion and
removal of the prosthesis will cause the attachments to
wear, so that some form of adjustment is desirable. e.g.:
• a. Chayes attachment
• b. McCollum unit

51. • Without adjustment potential: Lack of adjustment
potential renders this type of unit unsuitable for
removable prosthesis, as repeated insertion and removal
will cause the attachment to wear. They are useful for
joining a series of crowns without a common path of
insertion.

52. • B. Those whose retention is augmented by a mechanical
lock. e.g.: Schatzmann unit.

53. • Depending on the cross sections intra coronal attachments
can be classified into
• 1. H-Shaped flanges: The external frictional flange of H-
Shaped unit strengthens the attachment, without
increasing the size of the female part.
• 2. T-shaped flanges: E.g. Chayes attachment.
• 3. Attachments with a circular cross section. They are
suitable only for joining two sections of a fixed prosthesis.

55. •Attachments with auxiliary retentive
features: Auxiliary retentive features are
incorporated in some attachments in an effort
to provide more retention for a given
frictional area although no extra stability is
provided. A minimum of 4 mm vertical space
is necessary:
• They are screw and tube attachment, key and keyway/
interlocks, Sectional dentures, bar connectors

56. H shaped attachment
Single adjustment slot
MC COLLUM ATTACHMENT
• An H shaped
attachment indicated
for fixed movable
bridgework,
removable partial
dentures and distal
extension partial
dentures when cross
arch stabilized.
56

57. Two adjustment slots
STERN ATTACHMENT
H shaped configuration.
• This attachment is an
intra-coronal, active
friction grip
attachment to which a
distal hinge block has
been added.
• Used as a stress
breaker attachment
and in fixed removal
bridge work and RPDs.
57

58. Available as Rigid / Resilient
Rigid crismani attachment
Frictional grip
Mechanical grip
CRISMANI
ATTACHMENT
• These come in resilient and rigid
forms.
• The rigid types are available with
both friction and mechanical spring
clip retention mechanisms.
• They come in intracoronal active
friction grip as well as snap grip
varieties.
• The hinged, resilient type attachment
can be used in distal extension cases.
58

59. • 2. Extracoronal attachments:
• a. Projection units: These units are attached to the proximal
surface of a crown. E.g.: ASC -52.
• Those that provide a rigid connection. e.g.: Conex attachment.
• Those that allow play between the components. e.g.: Dalbo,
Ceka attachment.
• b. Connectors: These units connect two sections of a removable
prosthesis and allow a certain degree of play E.g.: Dalbo-fix
used between a telescope crown and partial denture.

60. • c. Combined units: The attachment features an extracoronally
placed hinge type unit connected to an intracoronal attachment.
E.g.: Schatzmann attachment consisting of an intracoronal section
with a projection.

61. STABILEX
• It is a bar with a double tube over
which fits the secondary part
containing two cross split cylinders
as the frictional element
• These split pins are activated with a
special key, which even the patient
can use and with which the pins may
also be unscrewed and replaced
61
Matrix
Patrix
Assembled

62. a) Patrix
b) Matrix
RESILIENT EXTRA CORONAL ATTACHMENT
DALBO / DALLA BONA ATTACHMENT
• These are known as Dalla bona slide
block or Dalbo stud anchor.
• The Dalbo attachment is a good
example of a ball and socket joint in
which the ball is cantilevered off the
abutment tooth and the socket is
attached to the prosthesis. The wall of
the metal socket has several small slits
to provide a resilient entrance to the
socket and offers some direct retention
to the attachment when the socket
engages the ball over its height of
contour .
• They are useful when there is minimal
vertical space available and rotation,
resilience and retention are desired.
62

63. Rigid system
Non-rigid system Stress
breaker
ROLE OF ATTACHMENTS AS STRESS BREAKER (BROKEN
STRESS PHILOSOPHY)
63

64. STRESS BREAKER DESIGNS (ASC-52)
• This is an example of an
extracoronal resilient
attachment that posses universal
resilience.
• It consists of an extracoronal
slide attachment with a spring
activated universal hinge joint
and adjustable retention.
• It is the smallest stress director
in dentistry and is used for distal
extension RPD’s.
64

65. Neys distal extension
stress breaker
• Ney attachments are
intracoronal snap grip
attachments.
• Available in 2 basic designs,
the familiar chayes with
adjustable wings and the
neyloc design with gingival
retention feature.
65

66. • Stud attachments are so called because of the shape of the
male units that are usually soldered to the diaphragm of a
post crown. They are among the simplest of all attachments.
They can provide additional retention, stability and support.
• Few stud attachments are entirely rigid because of their
small size. Gerber, Dalbo, Zest, ERA, Prosnap, Profix all are
stud attachments. Gerber is the largest stud unit.

68. DALLA BONA
• It is a simple attachment,
available in resilient, non-
resilient and stress broken
types.
• It is useful when there is
minimal vertical space available
and rotation resilience and
retention is desired.
• It consist of a single piece male
stud soldered to the coping and
a single unit female processed
within denture.
68

69. ROTHERMAN ECCENTRIC ATTACHMENT
• Advantages
• It is one of the smallest of stud attachments
and hence requires very little space (average
1.6mm).
• It is available in nonresilient and resilient
versions.
• Simple to use with adequate retention and
ease of maintenance.
• Disadvantages :
• Chair –side insertion of keyway is difficult.
69

70. ZEST ANCHOR
ATTACHMENT
• Consists of a metallic funnel shaped tube
cemented into the root canal of the tooth
and a polyethylene stud that is attached
to the denture base.
• The head of the stud squeezes past the
construction in the neck of the funnel to
retain the denture on the tooth. It derives
its retention from within the tooth
70

71. Cut section
SCHUBIGER ATTACHMENT
• Patrix : threaded
post / screw
• Matrix : recessed
collar, cap nut /
lock nut
71

72. • Stud attachments have numerous applications:
• 1. Overdenture being relatively small they can provide
additional stability, retention and support while the
positive lock of certain units can maintain the border seal
of the denture.
• 2. Non-vital partial denture abutments. The loads applied
in these circumstances can be considerable, so one of the
larger and stronger units is recommended.
• 3. For retention of a small tooth supported restoration
with non-vital abutment.

73. BAR
73

74. • Gilmore clip system (1913) - metal bar with retaining sleeve /
clip.
• Bar can be attached to the :
• Coping or crowns over the vital teeth
• Post coping on endodontically treated teeth
• Screwed down into the coping (implant system)
74

75. Customised bar
Dolder bar
Ackermann’s bar
CM rider bar
Hader bar
Andrews bar
75

76. Multiple sleeve bar joints
Single sleeve bar joints
BAR JOINTS 76

77. Round / circular
Oval / egg shaped
‘U’ shaped /
parallel sided bars
Depending on cross section 77

78. DOLDER BAR
• Egg shaped bar
in cross section
• Open sided
sleeve
• Two sizes 3.5mm
x 1.6mm,
• 3.0mm x 2.2mm
• Spacer – degree
of movement
78

79. Sagittal rotation
Rest position Vertical translation
MOVEMENTS SEEN IN DOLDER BAR
79

80. ACKERMANN BAR
• Available in different cross section
• Circular cross section – can be bent
in all planes
• A short extension of 5mm is carried
behind the most distal root and the
sleeve positioned on this section
• Prevents tendency for distal part to
rise when sticky foods are chewed.
• This is recommended where bar is
set an antero-posteriro curve to
prevent hinge rotation and motion.
• Multiple sleeve bar joints are more
versatile than single ones except
bars that have slightly rigidity.
80

81. CM BAR
• It is similar to
circular
Ackermann bar
with diameter
of 1.9 and is of
precious and
semi-precious
alloys, the latter
recommended
for long spans.
81

82. HADER BAR
• Prefabricated plastic
pattern are adapted to
master cast according to
its contour and cast in
alloy of choice .
• Sleeves of plastic have
to be replaced for
adjustments, hence
metal sleeves can be
substituted.
82

83. • Advantages of bar attachments :
• Rigidly splint the teeth
• Provides good retention, stability and support
• Provides cross arch stabilization
• Positioned close to the alveolar bone (exhibit less
leverage)
83

84. • Disadvantages :
• Bulk of bar
• Plaque accumulation
• Wearing
• Soldering procedure
84

86. MAGNET
86

87. • Since 1950 To retain maxillofacial prosthesis
• Alu, Ni, Iron,Cobalt alloy (alnico)
• Limited use – larger size
• 1960 “use of rare earth element” – High field strength
• – Can be used in smaller size.
• Somarium cobalt (Sm-Co) (Joseph Becker Hoffer 1967)
• Neodymium iron boron (Nd-Fe-B) – 20% stronger
• Somarium iron nitride – High magnetization
• Used for retention of mandibular overdentures (tooth and implant
supported over dentures)
87

88. Gilling’s magnetic attachment
(cobalt somarium alloy magnets)
“Split pole paired magnets”
Closed field magnetic system
Magnetic retainer with magnets
Magnetic keeper
88

89. • Advantages of magnetic attachment :
• Smaller size and strong attractive force
• Produce constant force – constant retention
• Easy to incorporate into the prosthesis
• Automatic reseating
• Boon for elderly patients (Parkinsonism, arthritic patient)
• Less lateral force to the abutment tooth
89

90. Jackson magnetic attachment
(cobalt somarium alloy magnets)
Cemented in keeper Screwed in keeper
90

91. • Disadvantages :
• Loss of retention due to corrosion or heat instability
• Requires encapsulation within inert alloys
• Cannot be repaired
• High cost
• Limited force transmission - Magnets can slide on their keepers.
91

92. • Applications:
• 1. They act as relatively rigid connection between the implants to
which they are attached by screws, which overcomes the divergence
between the implants
• 2. Robust and effective retainers.
• 3. When employed to connect roots, the fact that the bar is close to
the alveolar bone supporting the teeth results in far less leverage on
the roots than if the occlusal rests had been employed.
• 4. Bar joints are applicable for over dentures constructions.
• 5. The design and construction of bar attachments can provide the
denture with significant stability and retention.

94. • 5. Auxiliary attachments
• a. Screw units
• b. Friction devices
• c. Bolts
• d. Hinge flanges

95. Swing-Lock Removable Partial Dentures
• In the Swing-Lock removable partial denture, first described by Dr J.
Simmons in 1963, all or several of the remaining teeth are used to retain
and stabilize the prosthesis against vertical displacement.

96.  The prosthesis consists of a hinged buccal or labial
bar attached to a conventional major connector.
 Retention and stabilization are provided by this bar.
A Swing-Lock removable partial
denture exhibits a hinged labial bar
The labial bar is attached to the
framework by a hinge mechanism
(arrow) that permits it to open and
close like a gate.

97. Locking mechanism in the open
position
Locking mechanism in the closed
potion,(arrow).

98. • The labial bar is generally designed with
small vertical projection arms that contact
the labial or buccal surfaces of the teeth
gingival to the height of contour
Vertical projections of the labial bar
contact the remaining teeth

99. • These vertical arms look like I- or
T-bars and provide both retention
and stabilization for the prosthesis.
• The labial bars can also be designed
with acrylic resin retention
components, in which case
retention and stability are provided
by an acrylic resin denture base
attached to the labial bar.
A labial bar also may include
beads (arrows) to permit
attachment of an acrylic resin
veneer

100. • This design is used if the vertical projection bars would
produce a poor esthetic result or if extensive loss of gingival
tissue has occurred and a resin gingival veneer is needed to
improve appearance.

101. • Advantages
• The primary advantage of the Swing-Lock concept is that it
provides a relatively inexpensive method for using all or most of
the remaining teeth for the retention and stabilization of a prosthesis.
Alternatives to this type of treatment include (1) removal of the
remaining teeth and (2) fixed splinting of the remaining teeth and
construction of a conventional removable partial denture.

102. Disadvantages
• A Swing-Lock prosthesis can produce a relatively
poor esthetic result for patients with short or
extremely mobile lips.
• Obtaining perfect adaptation of a resin veneer is
difficult because the path of insertion is dictated by
the hinge movement of the labial bar.

103. • The remaining teeth are grasped firmly by the prosthesis.
A long distal extension base is likely to move toward the
tissue under the forces of occlusion.
• This movement can tip the teeth grasped by the prosthesis

104. CONCLUSION

105. • It is critical that the appropriate attachment be utilized for
each individual case situation. These classification systems
aids in having a broader view about the type of attachment
to be judiciously used since each clinical situation for which
an attachment is intended will place specific demands that
can be met, only if we have thorough idea about the diverse
attachments available.

106. REFERENCES

107. 1. The Glossary of Prosthodontic Terms. J Prosthet Dent
2017 ;117(5S):e1-e105.
2. Stewart, Rudd and Kurbker: Clinical Removable Partial
Prosthodontics; 2nd ed., Euro America Inc, Publishers
Tokyo,1997
3. Carr AB, Mc Givney and Brown DT: Mc Craken’s
Removable Partial Prosthodontics; 11th ed.

108. 4. Boitel HR. Precision attachments: an overview. In: Tylman SD,
Malone WFP, eds. Tylman’s theory and practice of fixed
prosthodontics. 7th ed. St Louis: The CV Mosby Co, 1978, chap 22.
5. Zlataric. The Effect of Removable Partial Dentures on Periodontal
Health of Abutment and Non-Abutment Teeth. JPeriodontology,
2002, 73: 137-144
6. Burns and Ward JE Review of attachments for RPD design
Classification and selection IJP 1990; 3(1) : 90-102

109. 7. Rudd KD, Morrow RM, Eissmann HF – Dental Laboratory
Procedures – Removable Partial Dentures. St. Louis, Missouri: CV
Mosby; 1986.
8. Amit Khare, Sumit Makkar, Roshna T. Full Mouth Rehabilitation
with Fixed and Removal Prosthesis using Extracoronal
Attachments: A Clinical Report. People’s Journal of Scientific
Research Vol. 4 (2), July 2011
9. Gerardo Becerra, Micheal Mac Entee. Classification of precision
attachments. J Prosthet Dent 1987; 58 (3): 322-327.

110. 10.Mensor MC. Classification and selection of attachments. J Prosthet
Dent 1973; 29: 494-97.
11.J. M. Sossamon. Spectrum of function- a classification system for
attachments in removable prosthodontic therapy. QI 1986; 17 (3): 52-
56.
12.Dr. Prabhakar angadi et al. Precision attachments-applications and
limitations. Journal of Evolution of Medical and Dental Sciences
2012; 1 (6): 1113-1121.
13.Harold W. Preiskel. Over denture made easy. A Guide to Implant and
Root Supported Prosthesis. 1996 Quintessence books; pgno; 87.

111. THANK YOU