implant dentistry

1. Prosthodontic components
in Dental implantology.
Maundu c. n

2. Outline
• Classify abutments
• Materials
• Advantages limitations, performance
• Customised abutments
• Dynamic abutments
• Connection between abutment and implant-
• internal hex perFomance of
• Platform shift
• Prosthesis , screw retained, cement retained , challenges, advantages etc
• Perfomamce
• Failures mechanisams about prosthetic phase. What to decide whne to use which .

3. Definition.
• ABUTMENT Portion of implant that supports and retains a prosthesis
or implant super structure (GPT - 9)

4. Classification
• TYPES
1. Depending upon retention
• Abutment for screw retention
• Abutment for cement retention
• Abutment for attachment
(Biden etal 2000)

5. Classification continued
2.Depending upon angulation
• Straight abutment
• Angled abutment

6. CLASSIFICATION CONTINUED
3.Depending upon design
• Flat topped abutment
• Tapered shouldered abutment
• Direct gold copings
(Biden etal 2000)

7. CEMENT RETAINED ABUTMENTS TYPES
• Types of abutment for cement retention
1.Single unit or one piece abutment
Single unit or one piece abutment - does not engage anti rotational hex
but fits flush with the implant platform
2 . Two piece abutment
Has one component to engage anti rotational hex of implant body and
other component to fixate the abutment and implant body together
(Biden etal 2000)

8. CEMENT RETAINED ABUTMENTS
ADVANTAGES
• Better passivity
• Easier to obtain esthetics
• Fewer porcelain fractures – due to occlusal surface integrity
• Less fatigue
• Manipulation in posterior region is easier with cement
• Loosen less often compared to that of screws
• Occlusal surfaces remain intact as there are no screw holes
Better axial loading(Bragger etal 2015) (Biden etal 2000)

9. DISADVANTAGES
• Difficult to retrieve unless soft cements are used
• Abutments sometimes must be prepared intraorally
• Gingival retraction may be needed
• When permanent cements are used evaluation and maintainence of
implants is difficult
• Increase in the momentum of force
(Bragger etal 2015)

10. • Elimination of screw access hole from the occlusal surface
• Control the thickness of metal and porcelain in an anterior restoration
• Develop proper emergence profiles

11. SCREW RETAINED ABUTMENTS
ADVANTAGES
• Low profile of retention
• Less momentum of force
• No risk of cement in the sulcus
• Easily retrievable
(Biden etal 2000)

12. DISADVANTAGES
• Loosening of the screws
• Difficult to obtain passivity
• Difficult to obtain esthetics
• Greater chances of porcelain fracture
• Access in posterior regions difficult risk of aspiration
(Biden etal 2000)

13. Literature review ; performance of screw
retained vs cement retained abutments
• There are few publications that comprehensively compare the 2 types of
retention.
• The aim of this review of the literature was to provide an overview of the
advantages and disadvantages of the cement- and screw-retained
restorations, and also to suggest some clinical situations that advocate for
one method of retention over the other.
• The factors that are affected by different methods of retention of the
prostheses to the implants are: ease of fabrication and cost, esthetics,
access, occlusion, retention, incidence of loss of retention, retrievability,
passivity of fit, restriction of implant position, effect on peri-implant tissue
health, provisionalization, immediate loading, impression procedures,
porcelain fracture, and clinical performance. (Rola shadid 2012)

14. CONCLUSIONS OF THIS STUDY
• The authors did not prefer one type of restoration over the other
because both types of restorations, screw-retained and cement-
retained, have certain advantages and disadvantages.
• However, based on reviewing the related literature, it has been
demonstrated that one type of restoration is more appropriate than
the other in some clinical situations. (Rola shadid 2012)

15. (Rola shaded 2012)

16. (Rola shaded 2012)

17. Factors that affect screw connection
1. Misfit
2. Poor abutment screw tightening
3. Excessive occlusal loading
4. settling of screws or abutment
5. inadequate screw design
Misfit has been reported to be as high as 66 micrometer between implant
and abutment in vertical direction , 10 degrees in rotational dimension and
99 micrometer in horizontal dimension Guidelines usually recommend the
screw to be tightened by 50 – 70 % of yield strength
(Bragger etal 2015)

18. ABUTMENT DESIGNS
(NASRIN 2010)

19. STRAIGHT ABUTMENT
-Indicated for replacing single tooth for large prosthesis up to full arch,
implant borne reconstructions
- used only when emergence profile are parallel
- if abutments are not parallel
– can be prepared by • Direct method
• Indirect method
(Nasarin 2012 )

20. ANGLED ABUTMENT
• Available in angulations from 10-30 degrees
• Improved esthetics
• To correct path of insertion
• Increase in angle
• Increase risk of fracture
• Placed as deeply as possible with most favorable axis orientation
• (Biden etal 2000) (Nasarin 2012 )

21. Literature review angled vs non angled
abutments
• Angled vs. Non-Angled Abutments Bruggenkate et al presented certain factors that may limit the
possibilities of placement of dental implant with proper angulation:
1. Anatomic structures. The height and width of the residual alveolar ridge, the mandibular nerve and the
nasal and maxillary sinus.
2. Shape and angle of alveolar process. The shape of the jaws and the maxillomandibular relation may
create problems either for placement of implants or for design and fabrication of the suprastructure. Most
problems are found in maxilla. The shape of the jaw determines the position of the implants that may
produce angulation or non parallel implants.
The solutions for these problems are surgical correction or bone augmentation of alveolar ridge, sinus
elevation or nerve repositioning.
The other alternative is the placement of implants in the area of greatest available bone and then to correct
the implant alignment with the use of angled abutments since the morphology and position of teeth are
determined by esthetic and functional consideration
The use of angled abutment was suggested as the treatment of choice in cases of anatomical limitations that
prevent axial implant placement.
Currently, a wide range of pre-angled abutments are available at specified divergence angles (15 degrees, 25
degrees, 35 degrees).

22. In addition, in certain cases custom angled abutments may be casted to achieve acceptable
esthetic outcome.
The main concern in using angled abutments is the adverse effect of non axial forces on the
survival of implants.
Sethi et al concluded in their five years clinical study of the angled abutments that there was no
difference in the survival rate of implants based on the use of angulated abutments ranging from
0-45 degree.
Significant increase in stress and strain with the increase in abutment angulations was found by
Clelland et al
However, they stated that this stress and strain is within physiological limit of bone. In a 3-D finite
element analysis study by Kao et al und that abutment angulation up to 25 degrees can increase
the stress in periimplant bone by 18% and the micromotion level by 30%.
Dixon et al found no significant dif ference between straight and angled abutments for deflection,
rotation and torque required to loosen abutment screws. Eger et al compared the effect of angled
and standard abutments on clinical outcomes and they stated that clinical examination revealed
no significant differences.

23. ABUTMENT DESIGNS FLAT TOPPED
ABUTMENT
ABUTMENT DESIGNS FLAT TOPPED ABUTMENT
• used to support bars for overdentures/ fixed detachable hybrid prosthesis
• Do not engage anti rotational component.
Advantage
– simplicity
Disadvantage
- Does not have counter rotational forces
- Unsuitable for single tooth replacement
- Straight emergence profileunesthetic in anterior maxilla (Biden etal 2000)

24. Abutment for attachment
• Uses an attachment device to retain a removable prosthesis
• Includes - Mesostructure bars
– continuous and non continuous Super structure attachments
– magnets , custom clips , hader clips of plastic or gold , dolder clips ,
ceka attachments , zest , zag anchors , octalinks , o rings , ERA
attachments , pin locks and lew attachments

25. TAPERED SHOULDERED ABUTMENT
Indicated in
– ars to overdentures, hybrid overdentures, single tooth replacement -
tapered design
-Resistance to lateral forces
-lower profile abutment collars
- subgingival margin
– esthetic -tapered shoulder
- angled at 9-15 degree (Biden 2000)

26. SPLINE ATTACHMENT
• Splines are fin to groove anti rotational design Consist of six external
components called tines which protrude 1mm from implant and are
matched to a female embedded in a abutment bas
• Used for over denture connection

27. MORSE TAPER ATTACHMENT
• Consist of 1 piece abutment post with 5 degree taper -resist rotation
and even removal -also referred to as cold welded design

28. DIRECT GOLD COPING
• Coping bypass abutment entirely
• Consists of two parts- coping and screw -porcelain is baked directly on
to coping
• Results in crown which attaches directly to implant body
• Coping engages antirotational component of implant Indications
• Single tooth restorations that don’t require alteration of angulation
• Limited interocclusal space Minimal soft tissue thickness
• Where subgingival margins are required (Nasarin 2012 )(Biden etal
2000)

29. Implant abutment connection
• The implant/abutment interface connection, by convention, is
generally described as an internal or external connection (Fig 1).
• The distinctive factor that separates the 2 types is the presence or
absence of a geometric feature that extends above the coronal
surface of the implant (Figs 2 to 4).
(Biden 2000 )

30. • The connection can be further characterized as a slip-fit joint, where a
slight space exists between the mating parts, and the connection is
passive,
• As a friction-fit joint, where no space exists between the mating
components and the parts are literally forced together.
(Biden 2000 )

31. • Mating surfaces are further characterized as being a butt
joint, which consists of 2 right-angle flat surfaces contacting,
or a bevel joint, where the surfaces are angled either internally or
externally (Fig 5).
The joined surfaces may also incorporate a rotational resistance and
indexing feature and/or lateral stabilizing geometry.
• This geometry is further described as octagonal, hexagonal, cone
screw, cone hex, cylinder hex, spline, cam, cam tube, and pin/slot.
(Biden 2000 )

32. Internal and external hex

33. INTERNAL HEX

36. PLAT FORM SWITCHING
• Platform switching is a method used to preserve alveolar
bione levels around implants.
• The concept refers to placing screwed or friction fit restorative
abutments of narrower diameter on implants of wider diameter,
rather than placing abutments of similar diameters, referred to
as platform matching. (Gpt 9 )

37. LITERATURE REVIEW
Cumbo etal 2013
BACKGROUND: The platform switching concept involves the reduction of the restoration
abutment diameter with respect to the diameter of dental implant. Long-term follow up
around these wide-platforms showed higher levels of bone preservation.
AIM: The aim of this article is to carry out a literature review of studies which deal with
the influence of platform-switched implants in hard and soft oral tissues. MATERIALS
AND METHODS: All papers involving “platform switching” that are indexed in MedLine
and published between 2005 and 2011 were used. Clinical cases, experimental and
nonexperimental studies were included, as well as literature reviews.
RESULTS: In our search, we analized 18 clinical cases and 3 reviews. The results indicate
that peri-implant bone resorption is reduced with platform switching system.
CONCLUSIONS: All papers written by different researchers show an improvement in peri-
implant bone preservation and satisfactory aesthetic results. Further long-term studies
are necessary to confirm these results. Key Words: Platform switching, Crestal bone
remodeling, Crestal

38. Guidelines for abutment selection
• Depth of soft tissue
• vertical height from implant head to the gingival margin Measured
with periodontal measuring probe
• labial margin of abutment is atleast 1mm subgingival
• Marked discrepancy between gingival heights around the margin
• Diameter close to that of cervical margin of the intended tooth to be
replaced.

39. Emergence profile
• Need atleast 3mm of vertical space from implant head to gingival margin
• Allows gradual transition from implant head.
Orientation
• Ideally implant is placed close to the long axis of missing tooth (thro incisal tip or
just palatally)
• Small degree of labial angulation – easily accomodated with standared
abutments
• If more labial angulation needed – use of standard abutment leads to
• Excessively contoured labial surface Porcelain surface too thin to mask the metal
structure
• Better results achieved with prepable / fully customised abutmen (Nasrin 2012)

40. ABUTMENT RETENTION
The retention of a fixed cemented restoration resist removal of the
retainer along the path of insertion
Resistance – opposes movement of the abutment under occlusal loads
and prevents removal of restoration by forces in apical and oblique
direction (GPT 9)

41. The tenets of retention and resistance include
• Abutment taper
– Retention of a crown decreases as the taper is increased from 6-25 degrees –
Ideal taper was recommended to be within 2-5 degrees of parallelism of path of
insertion
• Parallelism of axial walls has been recognized to be single most factor for
retention – Eames et al – found that clinically acceptable preparations present a
taper of 20 degrees.
• Abutment surface area
• There is linear increase in retention as the diameter increase for preparation with
identical height
• Diameter of an implant abutment for cement retention is often less than 5mm
which is comparable to prepared lateral incisor – so decrease in surface area
results in poorer retention than most natural abutment ( Eames et al 2001)

42. Abutment height
• A tall preparation offers greater retention than a short abutment
• Increase in height – increases surface area , increased resistance to lateral forces
• Height of the abutment must be greater than the arc formed by the crown rotating about a fulcrum at the
margin of the opposite side of the restoration face roughness increases the retention of a restoration by
creating micro retentive irregularities into which the luting agent projects( Eames et al 2001)
Surface roughness
 Retention is depEndent upon the type of burs along with the type and thickness of luting agents
 Large size cross cut fissure bur – reduce height and gross reduction of metal abutment post
 Coarse diamond – increase amount and depth of microscopic scratches on the surface to more than 40
micro meter
 Internal aspect of the casting should be air abraded with 50 micro meter alumina to enhance retention by
64%
( Eames et al 2001)

43. Commercially available
abutments
Review of some commercially available abutments

44. Commercially available abutments
– Steri oss abutment
– Paragon abutment
– Ceraone abutment
– Ceradapt abutment
– UCLA abutment
– Noble bio care abutment
– Estheticone abutment
– Mirus cone abutment
– Noble pharma single tooth abutment
– Branemark system angulated abutment –

45. THE ABUTMENT CONNECTION
• Definitive abutment connections
can be characterized in many
different ways.
• The basic categories
available are:
1. One- and 2-piece flat-top
2. One- and 2-piece conical
shouldered
3. UCLA-type plastic castable
4. UCLA machined/plastic cast to
cylinders
5. UCLA gold sleeve castable
6. One-piece fixed post
7. Two-piece fixed shoulder
8. Preangled fixed
9. Telescopic millable post
10. Ceramic
11. Single-tooth direct connection
12. One- and 2-piece overdenture
abutments

47. ESTHETICONE ABUTMENT
• Noble biocare abutment
- hex shaped,tapered sides
- features a female hex which interface with implant male hex head
and is secured by a titanium abutment screw
- indicated in multiple implant situation without causing esthetic
compromise with the metal display
- Designed to allow esthetic veneering material to be placed
subgingivally
- Abutment made of surgical grade titanium and available in 1,2,3 mm

48. CERADAPT ABUTMENT
- All ceramic alternative to metal abutments
- Pre machined precision milled abutment made to fit the implant hex - made up
of densely sintered 99.8% pure aluminium oxide which are pressed into desired
shape and subjected to sintering temperature of 2050 degrees Celsius
- Pore free strong wear resistant stable bio ceramic material
- Andersson and Oden etal showed flexural strength of 690 MPA and
demonstrated that the abutment can withstand tremendous loads without
fracturing it is a non metallic , non corrosive , bio compatible.soft tissue
response is excellent
- tooth coloured and light diffusion property
- more natural and esthetic implant crown
- used for implant supported single and multiple tooth restoration in the anterior
canine and premolar regions - can be either screw or cement retained

49. OCTA ABUTMENT
• Low profile component used with ITI implants
• Used in esthetically sensitive maxillary anterior region
• Pre fabricated gold caps are available for attachment to removable super structures -
Internal octagonal design – resistance against crown rotations
UCLA ABUTMENT
- Improved esthetics
- Gold alloy abutment screw retention increases the preloading force
- Abutment can be custom reangulated
- All abutment have a non rotating configuration
- Improved emergence profile

50. - Each restoration has a tapered interface similar to that of a standard
FPD restoration
- Multiple butt joint prosthesis interface avoided
- Lingual screw retention for fixed retrievability
- - practical and esthetic

51. CUSTOM REANGULATED UCLA ABUTMENT
- Eliminates need for prefabricated angled abutment Simplifies construction
- Results in better esthetics When implants are not parallel , parallelism
cannot be obtained
- Abutment fabricated to interface directly with the implant using a pre
machined gold palladium cylinder
- Secured with titanium abutment screw
- Pre machined internal hex interfaces with implant male hex provides
maximum resistance to lateral forces and screw loosening
– Lingual surface of abutment is tapped to receive a gold screw
– fixed retrievabiltiy.

52. Computer generated Procera abutment
• Custom abutment-designed by a computer and machined to exact
specification
• Head of implant impression made and working model is placed in the
scanner
• Readings of implant angulation and position are taken
• Using cad-cam soft ware, ideal abutment is generated
Advantages
Precise fit Ideal emergence profile
Improved esthetics
Proper restoration contours

53. NOBLE PHARMA SINGLE TOOTH ABUTMENT
- Titanium abutment cylinder connects to the implant fixtures
- Available in various sizes depending upon the thickness of peri implant tissues (
1-5 mm )
- Restorations are designed to be cemented
- Two piece elements (crown and abutment cylinder) is connected to implant
fixture with a titanium screw
MIRUS CONE ABUTMENT
- Used for multiple implant screw retained restorations
- Available with 1,2,3 mm collars
- Soft tissue thickness determines appropriate collar height
- Designed for situations where inter occlusal distance is minimal
- gold alloy screws with hex head retains abutment with implant

54. BRANEMARK SYSTEM ANGULATED ABUTMENT
• Developed by Noble pharma
• Designed to adjust access hole position,prosthetic screw angulation
Improved esthetics 30 degrees, 12 sided internally designed
component which can be in 12 different positions components:
Implant Angulated abutment Abutment screw
• Gold cylinder Prosthetic screw Brass replica Healing abutment
ASTRA ABUTMENT
• Presented with the option of 20 or 40 degree tapered top
• Used for fixed bridges / over dentures

55. Abutment try-in kit
• Provide replicas of abutment types that can greatly assist abutment
selection
• Tried intraorally or on a cast
• Made up of aluminium – not damage the implant
• Color coded for easy recognition
• Used for better screw access position ,marginal height and
emergence

56. References
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