basics about implants

1. DENTAL IMPLANTS – BASICS ,
CLASSIFICATION, TIMING, CASE SELECTION
Presented by
Cathrine Diana PG II

2. • INTRODUCTION
genera of implants
• Terminologies
• Classification
• Implants
• Bone
• Bone – implant interface- theories
• Case selection and treatment planning
• Surgical procedure
• Complications
• Conclusion

3. Introduction
• Dental Implant:- “A graft or insert set firmly or deeply into or
onto the alveolar process that may be prepared for its
insertion

4. GENERA OF IMPLANTS

5. • A thousand years earlier, Egyptians nailed
copper studs with seashells carvings that
looked like teeth
• In 1913, one of the first implant systems was
introduced by Greenfield in Boston.
• In 1939, also in Boston, Strock made solid
vitallium screws in root forms for dental
implants.
• in 1943 in Germany, Dahl developed his
button inserts, which are also known as
intramucosal Implants

6. • Goldberg and Gershkoff published
their findings regarding subperiosteal
implants in 1946.
• Success rates for subperiosteal
implants are around 90% at five years,
65% at 10 years.
• Possible risk factors are
• bone resorption,
• paresthesia,
• fracture of the mandible, and
• soft tissue problems

7. l
• The same year, Sollier and Chercheve reported
the vertical transfixation implant, or staple
implant.
• This implant is tapped from under the anterior
mandible and has three, four, five or seven pins
protruding into the mouth.
• In 1969, Linkow designed his blade implant
system.
• The system is still used
today very rarely

8. • Roberts, who introduced the ramus
implant idea in 1970.
• The ramus implant is inserted into three
locations, the ramus right and left sides
and the anterior mandible
• modern endosseous dental implants and
the titanium alloy
that Osseo integrates with bone and forms a
strong firm bond by Per-Ingvar Brånemark, a
Swedish medical professor, in 1951

9. TERMINOLOGIES

10. – IMPLANT COMPONENTS
– Crest module
– Body
– Apex region

11. • Abutment:- “it is the portion of the
implant, supports or retains
prosthesis or implant
superstructure (metal framework
that attaches to the implant
abutment and provide retention
for removable or fixed prostheses)
• Cement retention
• Screw retention
• To retain removable prostheses

12. Prosthetic component:
– Healing screw/PME Impression coping
Lab analog

13. • Immediate loading:
• Implant placement with primary stability and prosthetic
loading with a provisional prosthetic tooth at the same clinical
visit or With in 2 wks
• Early loading:
• Implants placed with primary stability and loaded with a
provisional prosthesis at a subsequent clinical visit .
• should follow the onset of osteogenesis since bone formation
is enhanced by mechanical stimulation. Therefore, early
loading should occur only after approximately 3 weeks of
healing

14. Conventional loading
• Implant placement (typically achieving primary stability) and
healing for 3 to 6 months in a submerged or non-submerged
mucosal orientation.
• This time frame reflects the requirement for osteogenesis and
woven bone remodelling to load-bearing lamellar bone and
acknowledges the original recommendations of Brånemark .

15. Classifications

16. • 1 )Depending on anatomic
site:
• Subperiosteal
• Transosteal
• Ramus frame

17. • Mucosal inserts /
subdermal /
Intramucosal
• Endosseous
• Endodontic

18. • 2) Depending upon surgical
procedure
• Single stage surgery procedure
• Two stage surgery procedure
• Direct single stage

19. • 3) Depending upon histological
features
• Fibro-osseous integration
• Osseo integration

20. • Depending upon shape
• Screws Cylinder screw
• Bullet shaped
• Basket
Plates / blades
• Root form

21. • 5 )Depending upon material used:
• Bioactive
• Ceramics Hydroxyappetite
• Bioinert
• Titanium carbon

22. Surface modifications of implant
materials
• Passivation
• Ion implantation
• Surface texturing

23. The implant- bone interface
• There are two basic theories regarding the bone-implant
interface.
a)Fibro-osseous integration
b) Osseointegration
Greek osteon, bone, and the Latin integrare, to make whole.

24. • To obtain a successful osseointegration Branemark and coworkers
proposed numerous factors.
• According to the proponents the oxide layer should not be contaminated
or else inflammatory reaction follows resulting in granulation tissue
formation.
• The temperature during drilling should be controlled by copious irrigation,
if not can inhibit alkaline calcium synthesis there by preventing
osseointegration.
• The first month after fixture insertion is the critical time period for
initial healing period. When loads are applied to the fixture during this
period primary fixation is destroyed.

25. Osseointegration Vs bio integration
• Meffert et al, (1987) redefined and subdivided the term
osseointegration into “adaptive osseointegration” and
“biointegration”.
• “Adaptive osseointegration” has osseous tissue approximating
the surface of implant without apparent soft tissue interface
at the light microscopic level.
• “Biointegration” is a direct biochemical bone surface
attachment confirmed at the electron microscopic level.

26. • Dr.charles Weiss, stated that the collagen fibers invest the implant,
originating at the trabeculae of cancellous bone on one side, weaving
around the implant, and reinserting into a trabeculae on the other side
• However, there was no real evidence to suggest that these fibers
functioned in the mode of periodontal ligament.
• the forces applied resulted in widening fibrous encapsulation,
inflammatory reactions, and gradual bone resorption there by leading to
failure.

27. Factors influencing the BIC
• Implant biocompatibility
• Implant surface/dimension
• Implant bed
• Loading condition
• Primary implant stability
• implant length and diameter.
• Surgical technique
• Bone quality and quantity

28. • Implant biocompatibility
• Materials used are:
• Cp titanium (commercially pure titanium)
• Titanium alloy (titanium-6aluminum-4vanadium)
• Zirconium
• Hydroxyapatite (HA), one type of calcium phosphate ceramic
material

29. • Implant surface
• Pitch, the number of threads per unit length, is an
important factor in implant osseointegration.
• Increased pitch and increased depth between
individual threads allows for improved contact area
between bone and implant.
• Moderately rough surfaces with 1.5µm also, improved
contact area between bone and implant surface.
• Reactive implant surface by anodizing (Oxide layer),
acid etching or HA coating enhanced osseointegration
• Implant bed

30. • Primary implant stability
• micromotion of less than 30 μm – no effect on osteointegration
• adequate‟ insertion torque
• the additional torque used to secure or evaluate fixation of an implant in
bone (30-35Nw)
• But may actually result in pressure necrosis and/or increase the strain
magnitude at the interface and therefore increase the amount of damage.
• implant length - > length better success rate
• less than 10 mm – 50% failure
Schnitman, Wohrle, Rubenstein, DaSilva, & Wang, 1997).

31. • Surgical technique:
• 47°C at less than 1 minute to avoid overheating the bone
The Heat generated is related to
• The presence and temperature of irrigation
• Amount of bone being prepared
• Drill sharpness and design
• Time of preparation
• Depth of the osteotomy
• Pressure on the drill
• Drill speed
• Variation in cortical thickness.

32. • Drill speed
• The speed of drills may be adjusted in relation to the quality of the bone
being prepared.
• D3 – 800 rpm
• D1- 2500 rpm proceed without exerting excessive pressure .
• Time of preparation
• pause approximately every 5 to 10 seconds.
• Pressure on the drill
• The average force placed on a hand piece during preparation of an osteotomy
is 1. 2Kg. Enough pressure should be used to proceed at least 1 mm every 5
seconds
• Lavelle has demonstrated lower drilling temperatures in cortical bone with
internally cooled drills.

33. • The zone of non-vital bone formed after surgical trauma has been
observed to be progressively remodelled and substituted by vital,
functional bone after 6 months, with peaks of activity in the very early
stages after implant placement .
• mechanical trauma that may cause micro-fracture of bone during implant
placement.
• Mechanical trauma can lead to osteonecrosis and possible fibrous and
granulation tissue encapsulation around the implant instead of Osseo
integration.

34. • Bone quality and quantity: The modulus of density and elasticity of bone
is an indicator of its quality and quantity. The less dense the bone, the
lower the modulus and the less amount of bone–implant contact
• These factors are critically important in relation to the success or failure of
osseointegration
• Based on the above, there is a general agreement among clinicians that
the mandibular interforaminal area contains the best quality bone
• (Misch, 1990; Misch, Qu, & Bidez, 1999).

35. BONE CLASSIFICATION SCHEMES
RELATED TO IMPLANT DENTISTRY

36. DIVISIONS OF AVAILABLE BONE
• Division A (Abundant Bone)
• >10-13mm height
• >5mm width
• >7mm mesio-distal length
• <30 degrees angulation
• C/I ratio <1
• Division A is most often restored with Division A root form implant.

37. • Division B (Barely sufficient bone)
• 2.5-5mm width
• >10-13mm height
• >12mm mesio-distal length
• <20o angulation between implant body and occlusal plane
• Crown/Implant ratio <1
• As the bone resorbs, the width of available bone first decreases at the
expense of the facial cortical plate. There is 25% decrease in bone width the first
year, and 40% decrease in bone width within the first 1 to 3 years after tooth
extraction. Once this Division B bone volume is reached, it may remain for more
than 20 years.
• Treatment options
• Modify by osteoplasty to permit the placement of root form implants 4 mm or
greater in width.
• Insert a narrow Division B root form implant.
• Modify the existing Division B bone into Division A by augmentation.

38. • Division C (Compromised Bone)
• Unfavorable in: Width (C-w)
• Height (C-h)
• Angulation (C-a)
• >30 degrees
• C/I ratio >1
• Treatment options :
(1) Osteoplasty
(2) Root form implants
(3) Subperiosteal implants
(4) Augmentation procedures
(5) Ramus frame implants
(6) Transosteal implants

39. Division D (Deficient Bone)
• Severe atrophy
• Basal bone loss
• Flat maxilla
• Pencil thin mandible
• Treatment options :
• most difficult to treat in implant dentistry.
• Autogenous bone grafts to upgrade the division are strongly
recommended before any implant treatment is attempted.
• Once autogenous grafts are in place and allowed to heal for 5 or more
months, endosteal or subperiosteal implants may be inserted, depending
on the division of bone obtained.

40. • Linkow’s classification of bone density (1970)
• Class 1 -this ideal bone type consists of evenly spaced trabeculae with
small cancellated spaces.
• Class 2 - the bone has slightly larger cancellated spaces with less
uniformity of the osseous pattern.
• Class 3 -large marrow filled spaces exist between bone trabeculae

41. • Lekholm and Zarb (1985)
• Quality 1 ; composed of homogeneous compact bone
• Quality 2 : thick layer of compact bone surrounding a core of dense
trabecular bone
• Quality 3 : thin layer of cortical bone surrounding dense trabecular bone
of favorable strength
• Quality 4 : thin layer of cortical bone surrounding a core of low density
trabecular bone

42. • MISCH’S CLASSIFICATION (based on bone density)
• D1: dense cortical bone
• D2: thick dense to porous cortical bone on the crest and coarse
trabecular bone within.
• D3: thin porous cortical bone on crest and fine trabecular bone within.
• D4: fine trabecular bone
• D5: immature, non-mineralized bone.
• D1: > 1250 HU; D2: 850 to 1250 HU; D3: 350 to 850 HU; D4: 150 to 350
HU; and D5: < 150 HU.

43. Type advantage disadvantage
D1
Anterior mandible
, 5 months healing time
dense lamellar bone with
complete haversian
systems
Less stresses -near crest
More BIC
fewer blood vessels
slower rate of 0.6 um /day
more difficult to prepare
Bone is easily overheated
D2-anterior mandible, followed by
the posterior mandible. Occasionally
ant .maxilla
bone healing within 4 month
bone provides excellent
BIC
intrabony blood supply –
reduce overheating
Improve primary stability
due to apical engage
Stress - around the crest greater
magnitude
D3- ant- maxilla post.either arch
TPS/HA
Maximum use of bone width
May need sinus grafting,additional
implant
Minimal osteotomy
Good blood supply
the stripping of the thin facial plates
during the osteotomy
More delecate to manage
less than 1500 rpm
<50% BIC
6month healing
D4-posterior maxilla
Need bone grafting
Maximum use of bone length
little or no cortical crestal bone
<25% BIC
to 8 months of undisturbed healing

44. Indications
• Patients with partially and fully edentulous arches.
• Patients with maxillofacial deformities.
• Patients who are unable to wear removable
dentures and have adequate bone for the
placement of implant.
• Good general health.
• Good oral hygiene & patient motivation.
• Patient should be emotionally stable, cooperative
and willing to keep the appointments required for
completion of treatment and maintenance

45. Contra-indications
• Uncontrolled or controlled diabetes/ medically compromised
• Chronic steroid therapy.
• High dose irradiation
• Smoking and alcohol abuse
• Pathologic conditions of the hard and soft tissues
• Presence of untreated or unsuccessfully treated periodontal diseases.

46. Preoperative diagnosis
• Clinical examination of the jawbone consists of palpation and
probing through the soft tissue (intra oral bone mapping) to
assess the thickness of the soft tissue at the proposed surgical
site.

47. Diagnostic imaging and technology
• Types of imaging modalities:
• Periapical radiograph
• Occlusal
• OPG
• Cephalometric
• CT – 3 dimentional
• CBCT

48. • Phase 1:
• Pre surgical imaging:
• Identify disease
• Determine bone quality and quantity
• Determine implant position and orientation
•
• Phase 2:
• Surgical and intra operative imaging:
• Focused on assisting in surgical and prosthetic
intervention in pt
• Phase 3:
• Post prosthetic implant imaging –
• to evaluate long term maintenance of implant and function

49. Dental implant site preservation and
development
• Alveolar ridge reconstruction with preprosthetic surgery
• Alveolar bone preservation following tooth extraction (immediate
implants, GBR, osseous grafting etc)
• Sinus lift/ grafting procedures
• Alveolar ridge augmentation using membranes
• Implant site development using ridge splitting technique
• Alveolar ridge development using distraction osteogenesis
• Growth factors in implant site development

50. Treatment planning
1 .prosthesis design
2. patient force factors
3. Bone density/availability in edentulous site
4 .Key implant position and number
5 .Implant size
6.Implant design

51. • prosthesis design-, implant supported denture over denture or fix
denture.
• patient force factors par functional habits- bruxism , clenching,
masticatory dynamic, crown height, opposing arch
• the force applied to the restoration differs by magnitude , duration type
and pre disposing factor
may need 1) additional implants that are wider in diameter
2)proper incisal guidance
3) narrow posterior occlusal table
4) enameloplasty of opposite natural teeth.

52. • Crown height space- should be between 8-12mm when not in range-
1) shorten cantilever length
2 )Increase number and diameter of implant and splint them
3) Fabricate removable restoration that incorporate soft tissue support
Remove them at night
• Bone density- softer bone Increase number and diameter of implant with
more and deeper threads. As more stress over crest so implant diameter is
more significant then length.
• minimum bone height for initial fixation and loading in D1=7mm,
D2=9mm,D3=12mm, D4->12mmm

53. Key implant position and number
• General guidance to determine key implant positions-
• No cantilever
• No three adjacent pontics
• Canine molar rule
• Arch dynamics
• Ideal one implant should replace one tooth and in edentulous implant
they should splint together.

54. Implant size
• Should be 1.5 mm from adjacent teeth
• Should be 3 mm from adjacent implant
• Should be 2 mm from adjacent anatomical
barrier
• Usually for mand. Incisors and max. LI=3-
3.5mm, for max. anterior and PM of both
arch and mand. Canine =4 mm. for all
molars =5-6mm

55. Implant position
• Ideally, occlusal forces should be
directed along the long axis of the
implants. Therefore ,The angle of the
osseous ridge crest is a key determinant
of implant angulation
• Maxilla anterior – 12 degree
• Mandible premolar - 10-15 degree
• Molar – 20-25 degree

56. Surgical procedure
• Implant site evaluation:
• Minimum bucco –lingual width –
7mm
• Mesio –distal 6.5mm
• Height – 11mm
• Soft tissue reflection – mid crestal
incision with a margin of 1.5mm
keratinized tissue buccally extending
to the sulcus of adjacent teeth

57. • Implant osteotomy:
• Start with 2mm end cutting drill at the center of crest
with 2500 rpm and copious irrrigtion upto 7-9mm
• Assess for proper position ,If incorrect position then
side cutting drill is used to stretch the osteotomy site.
• IOPA ensure the proper position with measuring tool
• Osteotomy proceeds with increasing size of twist drill
bit shorter than the size of desired implant
• Final implant position should clear the adjacent tooth
and the outer crestal cortical plate by 1.5mm

58. • Implant placement:
• After final osteotomy, the site is lavaged and aspirated to
remove debris and blood
• The implant is rotated with 30rpm (not more than 35 rpm) by
low speed high torque hand piece /hand ratchet
• The implant should inserted slightly above (one stage) or
below (Two stage). It should be rigid with no mobility on slight
compression

59. • Post insertion radiograph should be made to evaluate the
position , adjacent vital structure, crest module position. Any
correction can be made at this time. Low profile cover screw
is inserted into the implant body. Flaps most often
approximated with 4-0 PGA material
• If implant position is not with in the range of ideal , it may be
removed and reinserted after several months later in most
ideal position

60. Implant maintenance
• The principle of this method is to detect peri implant infections as early as
possible and to intercept the problems with appropriate therapy.
• The basis for this system is a regular recall of the implant patient and the
repeated assessment of the following key parameters around each
implant.
• The presence of plaque
• The bleeding tendency of the peri implant tissues
• Suppuration
• Presence of peri implant pockets
• Radiological evidence of bone loss.
• Optimally an implant should yield negative results for all these
parameters. In this case no therapy is needed and one may consider
increasing the length of recall interval.

61. • If plaque and /or an increased tendency to bleed are detected, then the
implants are mechanically cleaned using a rubber cup and polishing paste.
Instruments made of softer material than titanium may be used to remove
hard deposits. Oral hygiene practices should be checked, and the proper
plaque control technique should be instructed and reinforced (A)
• In the presence of pus or if first signs of peri-implant tissue destruction are
detected (pockets 4-5 mm & slight bone loss) regimen A is combined with
application of a local antiseptic (B). The periimplant pockets are irrigated
with 0.2% Chlorhexidene and the patient is advised to rinse twice daily
with 0.12% Chlorhexidene.

62. • If pocket depth > 5mm, radiograph is taken. If there is clear evidence of
bone loss, then a microbiological sample is taken. Evidence of anaerobic
flora, treatment A+B and in addition systemic antimicrobial therapy (c)
• If the bone destruction has advanced considerably, surgical intervention to
correct the tissue morphology on to apply GBR techniques may be
necessary (D).
• The goal of this cumulative treatment approach is to intercept peri
implant tissue destruction as early as possible and to avoid explanation
due to loss of osseointegration

63. Complications
• Inferior alveolar nerve injury is a serious complication with incidence
ranged from 0 to 40% .As a result, many important functions such as
speech, eating, kissing, make-up application, shaving and drinking were
affected. This influences patient’s quality of life and often resulted in
negative psychological adverse effects. The most common causes of
iatrogenic inferior alveolar nerve injuries are discrepancies of radiographs,
surgeon’s mistakes, low resistance of mandibular spongy bone and lack of
mandibular canal superior wall
• Incision line opening :
• Minor opening - proper oral hygiene practice with chlorohexidine rise –
wait for granulation of tissue
• If no granulation occur > 2wks – trim the margins - minor bleeding -
followed by granulation
• Implant exposure:

64. • Partial exposure –
• Remove cover screw- flush with chlorohexidine –insertion of permucosal
extention – hygiene maintenance
• Complete exposure
• Aggressive therapy – removal of cover screw- flush with chlorohexidine-
assess the bone level-reflect the soft tissue- curettage of granulation
tissue –implant surface cleaned wit citric acid/baking soda- followed by
bone grafting and membrane coverage
• Implant failure:
• Mobility of implant during healing period
• Pain , infection
• Radiolucency around implant whatever the cause, the implant should be
removed. Grafting and reinsertion can be done after 8-10wks.

65. Conclusion
• Dental implants have overall had high success rates, but their
placement and restoration still have the boundaries of both
biomedical science and art.
• The effectiveness of different designs of implant-supported
prostheses as well as associated treatment modalities,
prostheses retention and stability, leads to improvement in
speech, function and quality of life trials

66. Reference
1. Implant dentistry- Carl Misch
2. Clinical periodontology- carranza 9th edition
3. Periodontal Ligament formation around Ti implant using
cultural pdl cells; a pilot study. Byung-Ho Choi (I.JOMI
2000, 15:193). .
4. Implants and components: Entering the new millennium.
Paul Binon IJOMI 2000, Vol 15 No.1.
5. Current status of dental implants. A periodontal
perspective. Perry Kokkevold. IJOMI 2000 vol. 15(1)
6. Bone implant interface around titanium implants under
different loading condition. Romanos JP 2003 OCT 74 (10).
7. Longevity of dental implants in type IV bone: a systematic
review Int. J. Oral Maxillofac. Surg. 2014; 43: 1108–1116

67. 9. Heat generation and drill wear during dental implant
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12.Misch CE. Bone density: A key determinant for clinical success. In:
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