immediate implant loading

1. BHUVANESH KUMAR .D.V
IMPLANT LOADING

2. IMMEDIATE
LOADING OF
IMPLANTS

3. Table of Contents
Terminologies
 Immediate loading
Advantages, and Disadvantages,
 Indications and Contraindications
Rationale of immediate loading
 Factors influencing them

4. Immediate Occlusal Loading : An implant is
placed with adequate primary stability its
corresponding restoration has full centric
occlusion in maximum intercuspation and
must be placed within 48 hours post
surgery.

5. • Early loading : Early Loading Protocol is wherein a
provisional prosthesis was inserted at a subsequent
visit prior to osseointegration (between 2 days to 3
months after surgery). Though the implants, were not
loaded the same day, this protocol directly challenged
the healing process by introducing loading during
wound healing. A fundamental goal of early loading is
improving bone formation in order to support occlusal
loading at two months.

6. • Conventional Loading Protocol : is the original
healing periods as envisaged by different implant
systems, typically after 12 to 24 weeks.
• Delayed Loading Protocol : is one in which the
healing period was extended due to the
compromised host site conditions and, typically,
prosthesis connection is later than the conventional
healing period.

7. • Occlusal loading : means that the immediately or
early loaded prosthesis is in contact with the
opposing dentition.
• Non-occlusal loading : means that the
immediately or early loaded prosthesis is not in
contact with the opposing dentition. It should be
recognized that in non-occlusal loading, forces on
implants could be generated through the oral
musculature and food bolus.

8. • Immediate Non Occlusal Loading : An implant is
placed with adequate primary stability but is not in
functional occlusion. These implant restorations are
essentially used for esthetic purposes, frequently in
single tooth or short span applications. Immediate
non occlusal loading is often performed to provide
the patient with aesthetic or psychological benefit
during implant therapy, particularly when a
provisional removable prosthesis is undesirable
during the healing period.

9. Evolution of the Concept of Implant
loading
The surgical and prosthetic protocols for
the development of a predictable direct
bone-to-implant interface were first
developed and reported by Branemark et
al.

10. • BRANEMARK’S ORIGINAL PROTOCOL :
• 3 - 6 months
• Osseointegration
4-6 Months
Period
Tooth Extraction
Stage I Surgery
or Implant Placement
Stage II Surgery or
Prosthesis Placement

11. A non submerged, one stage surgery
where loading of implant with
provisional restoration is done at the
same appointment or shortly thereafter.
Immediate loading

12. Successful reports of early and
immediate loading
Presently, early and immediate loading
protocols are reported by an enhancing number
of clinical (Schnitman et al 1990 , Henry et al
1994, Tarnow et al 1997) and experimental
publications.

13. INDICATIONS
• Adequate bone quality ( type I, II and III)
• Sufficient bone height ( i.e. approximately 12mm )
for a minimum length of 10 mm implant
• Sufficient bone width ( i.e. approximately 6 mm)
• Ability to achieve an adequate antero posterior
spread between the implants. A poor AP spread
decreases the mechanical advantage gained by
splinting and the ability to cantilever the restoration

14. CONTRAINDICATIONS
• Poor systemic health
• Severe parafunctional habits
• Bone of poor quality ( e.g. type IV)
• Bone height less than 10 mm
• Bone width less than 6 mm
• Inability to achieve an adequate AP spread

15. Rationale for Implant Immediate Loading
• Thermal injury & Surgical trauma- MINIMIZE
• Implant osteotomy & implant insertion- lamellar bone
becomes woven bone
• The interface weakest, at risk of overload at 3 to 6 weeks
after surgical insertion- failure
• Temp : 38 ˚C – 41 ˚ C (Shawaray et al 2002)
• Slow intermittent pressure with irrigation and sharp drills

16. Bone remodelling
A rationale for immediate loading- to reduce the risk of fibrous tissue
formation & to minimize woven bone formation and promote lamellar
bone maturation to sustain occlusal load.
• Bone is loaded by the implant prosthesis, the interface begins
to remodel again, the trigger for this process is strain, not the trauma
• Remodeling - bone turnover
• Reactive bone- the woven bone
formed from the mechanical response

17. Guidelines for immediate loading (Misch &
Scortecci)
to reduce stress and resulting micro strain at the
developing interface.
Bone Microstrain:
 Loaded bone changes its shape. This change may be
measured as strain.
 Frost has developed a microstrain language for bone
based on its biological response at different microstrain
levels.

18. However, at levels of
20% to 40% of this
value, bone already
starts to disappear or
form fibrous tissue
and is called the
pathologic overload
zone.
Bone fractures at 10,000 to 20,000 microstrain units. (1-
2% strain)

19. The ideal microstrain for bone is called
the physiologic or adapted zone.
The mild overload zone corresponds to
an intermediate level of microstrain
between the ideal load bearing zone and
pathologic overload. In this strain region,
bone begins a healing process to repair
micro fractures, which are often caused
by fatigue.

20. Therefore one method to decrease
microstrain and the remodeling rate in
bone is to provide conditions that
increase functional surface area to the
implant-bone interface.
The surface area of load may be
increased in a number of ways:
implant number, implant size,
implant design, and implant body
surface conditions

21. Surface area factors :
1. Implant number:
8 or more (splinted) maxillary arch
6 or more (splinted) the mandible

22. 2. Implant size: Larger-diameter
 Each 3 mm increase in length- 20% more
surface area.
 Initial stability
 wider root form implants provide greater
bone contact
 implant diameter also varies according to
region

23. 3. Implant design :
 more threads ( Biohorizon -0.4mm, ITI -1.5 mm
pitch)
 deeper threads (Sterioss, NB -0.22mm, Biohorizon-
0.44mm)
 square or plateau-shaped threads
Threaded implant – more depth of bone from day 1.

24. 4. Implant surface condition :
 Hydroxyapatite-coated ( D4).
 Rough versus smooth or machine
 surface condition implants

25. Force factors :
1. Patient condition: Parafunction, crown height
, muscular dynamics
Parafunctional forces like clenching and
bruxism-
significant magnitude and duration of forces
with more shear component (horizontal
forces)

26. 2. Implant position:
• maxilla- bilateral canine position &
bilateral molar position
• mandible- at least three implants,
one in the anterior and one in each
posterior region
• Increased anticipation of forces –
Increase the implant number

27. 3. Occlusal load direction
• Narrow occlusal tables and no
posterior offset loads
• Long-axis loads to the implant bodies
• No posterior cantilevers should exist
on transitional restorations

28. FACTORS INFLUENCING
IMMEDIATE LOADING
The majority of immediate implant loading
studies reported similar success rates when
compared to the traditional 2-stage approach.
Data from the current available literature
already suggest that several factors may
influence the results of immediate implant
loading.

29. These could be divided into the following four categories:
1) Surgery-related factors
Primary implant stability
Surgical Technique
2) Host- related factors
Bone quality and quantity
Wound healing
3) Implant-related factors
Implant design confiquration
Implant surface coating
Implant length
4) Occlusion-related factors.
Quality and quantity of force
Prosthetic design

30. SURGERY-RELATED FACTORS
• Primary Implant Stability
Of all factors involved, Primary Stability seems to
be the most important determining factor on
immediate implant loading.
Functional loading placed on an immobile implant
is an essential ingredient to achieve
osseointegration (Roberts et al. 1984)..

31. If an implant is placed in the soft spongy
bone with poor initial stability, it often
results in the formation of connective
tissue encapsulation, similar to the
pseudoarthrosis observed in an
unstabilized fracture site

32. Micromovements of more than 100 µm are sufficient
to jeopardize healing with direct BIC.
Micromotions at the bone–implant interface beyond
150 µm resulted in fibrous encapsulation instead of
osseointegration.
It can be further speculated that these movements
would be detrimental in cases with immediate
implant loading.

33. • In summary, when primary stability is
achieved and a proper prosthetic
treatment plan is followed, immediate
functional implant loading is a feasible
concept.
• However, if the primary fixture stability
cannot be achieved or is questionable, it
is strongly recommended to follow a
conventional treatment protocol including
an adequate healing time before loading.

34. Surgical Technique
Gentle surgical placement is also a key element for
implant success regardless of the applied treatment
protocol.
Excessive surgical trauma and thermal injury may lead
to osteonecrosis and result in fibrous encapsulation
of the implant. 1988).
Heat generated during drilling without adequate
cooling is associated with bone damage.

35. It has been shown that a temperature over
47˚C for 1min causes ‘heat necrosis’ in the
bone (Eriksson & Albrektsson 1983).
Without irrigation, drill temperatures above
100 ˚ C are reached within seconds during
the osteotomy preparation, and consistent
temperatures above 47 ˚ C are measured
several millimeters away from the implant
osteotomy (Yacker & Klein 1996).

36. In addition, it is critical for the success of implants
that adequate load be placed on the drill during
the preparation of osteotomies.
It has been demonstrated that independently
increasing either the speed or the load caused an
increase in temperature in bone.
Interestingly, increasing both the speed and the
load together allowed for more efficient cutting
with no significant increase in temperature
(Brisman 1996).

37. Other factors related to heat generated
into bone include amount of bone
prepared (Eriksson et al. 1984a), drill
sharpness and design (Matthews & Hirsch
1972; Wiggins & Malkin 1976; Eriksson et
al. 1984b), depth of the osteotomy
(Babbush & Shimura 1993; Haider et al.
1993), and variation in cortical thickness
(Hobkirk & Rusiniak 1977; Eriksson &
Albrektsson 1984

38. It is shown that implant surgery generates
micro-fractures in the surrounding bone,
especially when press-fitting is intended. These
fractures heal according to the following
cascade (Schenk & Hunziker1994) :
 angiogenesis,
 osteoprogenitor cell migration,
 woven bone scaffold formation,

39. When a proper surgical/prosthodontic technique
is followed, the crestal bone loss around
immediately loaded implants seems to be in the
normal range when compared to a submerged
protocol.
Crestal bone loss was found to be 0.14mm in
immediately loaded implants vs. 0.07mm in the
delayed approach in a period between 6 and 18
months (Ericsson et al. 2000a).

40. • Cooper et al. (2001) reported a mean
change in marginal bone level of
0.4mm at 12 months in single early
loaded implants

41. HOST-RELATED FACTORS
Bone quality & quantity
Histological data on immediately loaded
implants have demonstrated not only a direct
bone interface contact, but also a favorable
bone quality around the fixtures.
Clinically, host bone density plays an important
role in determining the predictability of the
immediate implant loading success.

42. An implant placed in compact dense
bone is more likely to ensure initial
stability and, hence, better able to
sustain such immediate forces.

43. Resonance frequency analysis indicated that
implants are as stable at the time of placement
as when measured at 3–4 months postsurgery,
when placed into dense bone.
These results support the concept of direct
loading of implants when inserted in the
mandibular interforaminal regions. Therefore,
this homologous, dense bone type may
present several advantages for immediate
loading implant dentistry.

44. The cortical lamellar bone may heal with
little interim woven bone formation,
ensuring good bone strength while healing
next to an endosteal implant (Roberts et al.
1987; Roberts 1993).
In addition, its fine porosity (10%) favors
better mechanical interlocking compared
to soft cancellous bone.

45. As mentioned earlier, fine trabecular
bone presents the most difficult
endeavor to obtain rigid fixation, no
matter which implant is used.
For the reasons just mentioned, this
type of bone may be unsuitable for
immediate loading implant
techniques

46. Within the limited available information, it
appears that primary stability, more than
the arch (anatomic) location, may be the
fundamental requirement for immediate
implant loading techniques.
On the other hand, there has been no
unanimous protocol to be followed
regarding bone density and number of
implants, or type of prosthesis to be used in
immediate loading cases.

47. MECHANICAL PROPERTIES OF BONE
The modulus of elasticity is related to bone
quality. The less dense the bone, lower the
modulus. The amount of bone- implant contact is
also less – dense bone.
The strength of the bone is directly related to
density of the bone. Softer the bone, weaker the
bone trabeculae.

48. Wound Healing
Metabolic diseases that directly affect bone
metabolism such as osteoporosis/osteopenia
or hyperparathyroidism may significantly
influence implant wound healing.
Human trials have demonstrated that dental
implant placement in patients diagnosed with
osteoporosis may be successful over a period
of many years if an extended healing period is
advocated.

49. So far, no attempt has been made in loading
implants immediately in patients who are
diagnosed with systemic diseases such as
diabetes and hyperparathyroidismas well as
smokers.
A similar situation is also true for patients who
have undergone radiation therapy. Therefore, it
is strongly suggested to follow the standard 2-
stage protocol or even utilize longer periods of
healing in patients diagnosed with these
disorders.

50. The same standard guidelines are
suggested to be used in smokers or
patients under radiation therapy on the
oral cavity, until future research proves
otherwise.
Prior to surgery, a medical consultation
and thorough explanation of possible risks
to patients should be mandatory.

51. Under optimal conditions (atraumatic surgery), it has
been demonstrated that only after 6 weeks of
implant placement, lamellar bone was present at or
near the implant surface (Roberts et al. 1984).
The surrounding bone heals according to the cascade
mentioned earlier: angiogenesis, osteoprogenitor cell
migration, woven bone scaffold formation,
deposition of parallel- fibered or lamellar bone, and
secondary bone remodeling.

52. In conclusion, it can be speculated that
immediate loading of dental implants
may accelerate bone formation, but it
is also imperative to state that primary
stability is essential for this process to
occur.

53. IMPLANT-RELATED FACTORS
Implant Design/Configuration
Implant configuration has long been considered
as an essential requirement for implant success.
As a general concept, the screw type implant
design develops higher mechanical retention as
well as greater ability to transfer compressive
forces (Skalak 1985; Wolfe & Hobkirk 1989;
Lefkove & Beals 1990; Randowet al. 1999

54. The screw design not only minimizes micro-
motion of the implant but also improves the
initial stability, the principal requirement for
immediate loading success.

55. Additionally, the thread increases surface area
(Misch 1999). Studies have shown the absence
of fibrous tissues at the interface of
screwshaped implants, even if they are loaded
immediately after insertion (Skalak 1985; Wolfe
& Hobkirk 1989).
Hence, due to its mechanical retention
properties, it is generally recommended to use
threaded-type implants for immediate loading
cases.

56. However, the cylinder type implant would
appear contraindicated for immediate or
early loading regimens due to lowering of
primary stability and less resistance to
vertical movement and shear stress.

57. Implant Surface Coating
Rough implant surfaces render a significant increase
of BIC (Buser et al. 1991; Wennerberg et al. 1995;
Trisi et al. 1999).
The shear strength of implants with a rough surface was
shown to be about 5 times as high as that of
implants with a smooth surface (Li et al. 1999).
In addition, greater forces are required to remove
implants with a rougher surface compared to
implants with a smoother surface.

58. Human histological data reported by Piatelli
et al. (1993, 1997b) showed that a mature,
compact, cortical bone was formed around
the immediately loaded implant, with 60–
90% BIC.

59.  The reason for clinical success regardless of implant
surface coating may be due to the type of bone utilized
in a majority of human trials.
 As mentioned before, most of the studies have
focused on using the anterior mandible, where the
densest bone is located.
 It seems to suggest that the initial mechanical
interlocking between threads and dense bone may
overcome the beneficial properties that each coating
type provides.
 The same parameters showed that thread design was
more of a determinant than surface characteristics for
primary stability into softer type IV bone.

60. • Implant Length
The implant length may also influence the outcome of
immediate implant loading.
For every 3mm increase in length, the surface area of a
cylinder-shaped implant increases by an average of 20–
30% (Misch 1999b).
One study has reported 50% failure rate with immediate
loading for implant lengths less than 10mm (Schnitman
et al. 1997).
The majority of studies have suggested that implants
should be 10mm long to ensure high success rates.

61. OCCLUSION-RELATED FACTORS
Quality and Quantity of Force
o Controlling functional forces is one of the ingredients for
obtaining success of immediate implant loading.
o Sagara et al. (1993) found more crestal bone loss in the
loaded 1-stage implant group when compared to the 2-stage
unloaded control group (Sagara et al. 1993).
o It was suggested that the early occlusal loading during
healing may account for this observation, since early loading
may interfere with the ability of new one being formed to
replace the necrotic bone at the implant/bone interface
resulting from surgical trauma (Albrektsson et al. 1981).

62.  Vertical forces applied during function
are less detrimental to implant stability
rather than oblique or horizontal forces.
Therefore, bruxism/occlusal overload
has been considered as a possible
contraindication for immediate implant
loading due to higher implant failure
rates.

63. Prosthetic Design
 Primary stability can be enhanced when cross-arch
implant splinting is performed.
Therefore, this prosthetic approach is recommended
in immediate implant loading (Ledermann 1979,
1983; Salama et al. 1995; Spiekermann et al. 1995;
Tarnow et al. 1997; Randow et al 1999). Glantz et al.
(1984a, 1984b) have demonstrated that the most
favorable loading conditions were achieved via rigid
fixed devices.

64. • Tarnow et al. (1997) used cast metal frame-
enforced provisional restoration to ensure
optimal stability and a high success rate for
immediately loading implants. The authors
further suggested that the temporary
prosthesis, once inserted, should not be
peaked or removed during the healing period
to avoid any unnecessary movement
• Avoid using cantilevers in the fixed implant
provisional restorations since they increase
load to the terminal fixture by 2-fold

65. When reviewing the literature, it seems to
suggest that cross-arch splinting as well as
potential load and movement caused by
prostheses removal should be avoided in
immediately loaded implant cases.
 Careful occlusal analysis, such as
assessment of parafunctional habits and
distribution of occlusal support by
remaining teeth, is also essential when a
loading regimen for implants is
considered

66. Implant supported immediate fixed prosthesis for
completely edentulous patient
Primarily 2 different options are available for immediate
occlusal loading for the completely edentulous patient
desiring a fixed prosthesis
• The first option loads the implants the same day as the
surgery.
• The second option is to place the implants and make an
impression at the surgery. Then at the suture removal
appointment 7 to 12 days later, the dentist delivers the
transitional fixed prosthesis.

85. Immediate loading concept in partially
edentulous arch
• Non functional immediate teeth concept (N- FIT Concept) – Carl
E Misch.
• Rather than immediate loading of the implant, most
reports suggest immediate restorations rather than
full occlusal loading.
• Because the patient most often has enough remaining
teeth in contact to function, the transitional
restoration is primarily for esthetics, and the implant
prosthesis is completely out of occlusion.
• Therefore a nonfunctional immediate teeth (N-FIT)
concept is suggested

88. REVIEW

89. • 1990 Schnitman et al initially described
immediate loading off mandibular
implants with a detachable hybrid
prosthesis, however a statistically
significant number of the immediately
loaded implants failed.

90. • 1994 Henry et al placed 6 mandibular implants in a
series of 5 patients 4/6 implants immediately
loaded with provisional removable overdenture
then , at 7 weeks a permanent prosthesis was
placed. 100% implant success.

91. Babbush et al (1986) reported a cumulative success
rate of 88% on 1739 immediately loading TPS
implants. Subsequently, many authors have
shown the possibility of loading implants
immediately.

92. Primary guidelines for immediate
loading ( Tarnow -1997)
In cases where early loading is deemed appropriate,
Tarnow has suggested a set of guidelines to help
achieve clinical success:
Immediate loading should be attempted in edentulous
arches only to create cross-arch stability.
Implants should be at least 10 mm long.
A diagnostic wax-up should be used for template and
provisional restoration fabrication.

93. A rigid metal casting should be used where possible.
A screw-retained provisional restoration should be
used where possible.
If cemented, the provisional restoration should not
he removed during the 4- to 6-month healing
period.
All implants should be evaluated with Periotest (a
measure of the degree of resistance to
perpendicular force) at stage 1, and the implants
that show the least mobility should be utilized to
provide resistance to rotational forces.

94. The widest possible anterior-
posterior distribution of implants
should be utilized to provide resistance
to rotational forces.
Cantilevers should be avoided in the
provisional restorations.

95. Success criteria of implants
Schuitman and Schulman criteria (1979)
1) The mobility of the implant must be less than 1mm when
tested clinically.
2) There must be no evidence of radiolucency
3) Bone loss should be less than 1/3rd of the height of the
implant
4) There should be an absence of infection, damage to
structure or violation of body cavity, inflammation present
must be amneable to treatment.
5) The success rate must be 75% or more after 5 years of
functional service.

96. Albrektson and Zarb G (1980)
1) The individual unattached implant should be immobile when
tested clinically
2) The radiographic evaluation should not show any peri -
implant radiolucency
3) Vertical bone loss around the fixtures should be less than
0.2mm annually after first year of implant loading.
4) The implant should not show any sign and symptom of pain,
infection, neuropathies, parastehsia, violation of mandibular
canal and sinus drainage.
5) Success rate of 85% at the end of 5 year observation period
and 80% at the end of 10 year service.
6) Implant design allow the restoration satisfactory to patient and
dentist. - Smith and Zarb (1989)

97. SUMMARY
The requisites for predictable osseointegration of
immediately loaded implants have yet to be
determined. One parallel consideration is whether
provisional loading of a tissue borne prosthesis over
an implant during the osseointegration (healing)
period will affect the integration of that implant. To
date there is no scientific evidence (and no clearly
documented subjective clinical evidence ) that early
failure of dental implant can be attributed to early -

98. -loading or overload resulting from a tissue-
supported interim prosthesis being worn over a
recently placed dental implant. Loading of implant
through the use of an interim restoration has not
been documented as a cause of early implant
failure. It is also safe to state that, at this time ,
there is no scientific evidence that the factor
associated with implant restoration (provisional or
restorative) have a predictable impact on the
survival of the supporting implant.

100. THANK YOU