implant loading part 1

1. IMPLANT LOADING
BHUVANESH KUMAR.D.V

2. Terminologies

3. Brànemark's loading protocol
Flush with bone level, cover with gingiva.
Final prosthesis after 3 to 6 months of
initial healing.
Soft/ hard diet.

4. Progressive loading
Flush with bone level, covered with gingiva.
Provisional prosthesis brought progressively
into occlusion, depending upon bone
density.
Soft/ hard diet.

5. Non submerged single stage protocol
Non-submerged implants, flush within 1-2 mm
of gingival level
Soft diet
Immediate functional loading
Temporary restoration fitted on the same day
as surgery, in occlusion
Soft diet

6. Immediate non-functional loading
Temporary restoration fitted on the same day
as surgery, not in occlusion
Soft diet
Early loading
Final crowns within 3 weeks from surgery, in
occlusion
Soft/ hard diet

7. Delayed loading
Implant subjected to loading after more than
6 weeks post surgery
Soft/ hard diet
Anticipated loading
Provisional prosthesis is fitted after about 2
months after surgery
Soft/ hard diet

8. Prosthetic rehabilitation of missing structures in
the oral and maxillofacial region in accordance
with DeVan's principle of preservation has been
the ultimate challenge to the prosthodontist.
Over the years, traditional methods of tooth
replacement are slowly and steadily being
replaced by newer modalities like implants.

9. Dental implants were commonly loaded at
placement because immediate bone
stimulation was considered to avoid crestal
bone loss (Linkow & Chercheve). Fibrous
tissue interposition was considered the
optimal response to implants as it was
mimicking the natural periodontal
ligament.

10. In contrast to all the experimental studies
of that time, Branemark et al (1969)
showed that direct bone apposition at the
implant surface was possible and lasting
under loading at the condition that
implants were left to heal in a submerged
way.

11. Success with Brànemark's protocol still has a
deterring factor in the form of extended
treatment period, which sometimes preclude
patients from resorting to implant therapy.
Increasing functional and aesthetic challenges
have prompted implantologists to reduce the
treatment period by loading the implant
immediately at the time of placement.

12. After an initial direct bone–implant interface has
been obtained and confirmed at the post healing
stage II surgery, the implant is most at risk for
failure or crestal bone loss within the first year
after loading
The three most common causes of early
prosthetic-related implant complications are non-
passive superstructures, partially unretained
restorations, and loading of the implant support
system beyond the strength of the bone– implant
interface

13. The external (cortical) and internal (trabecular) structure
of bone may be described in terms of quality or density
which reflects the
The density of available bone in an edentulous
site is a determining factor in treatment
planning, surgical approach, implant design,
healing time, and the need for initial progressive
bone loading during prosthetic reconstruction.

14. Misch first proposed the concept of progressive or
gradual bone loading during prosthetic
reconstruction to decrease early implant failure
Misch et al. reported on 364 consecutive implants
in 104 patients with 98.9% survival at stage II
uncovery followed by a progressive loading
format and found no early loading failures during
the first year of function
Misch CE, Hoar JE, Hazen R, et al: Bone quality based implant system: a
prospective study of the first two years of prosthetic loading, J Oral
Implantol 25:185–197, 1999.

15. Misch CE: Gradual load on an implant restoration, St Petersburg,
FL, 1980, Tatum Implant Seminars lecture
Misch CE, Poitras Y, Dietsh-Misch F: Endosteal implants in the
edentulous posterior maxilla—rationale and clinical results, Oral
Health 90:7–16, 2000
Kline R, Hoar JE, Beck GH: A prospective multicenter clinical
investigation of a bone quality based dental implant system,Implant
Dent 11:224–234, 2002.

16. Scientific Rationale of
Bone Density–Based
Implant Treatment

17. Bone Strength and Density
Bone density is directly related to the
strength of bone before microfracture
The different
densities of bone
have a
different strength.
Type D1 bone is
strongest, and
type D4 bone is
the weakest.

18. It should be noted that the strength of bone
studies were performed on mature bone
types. Bone is 60% mineralized at 4 months
after implant surgery, and the strength of
bone is related to the amount of
mineralization

19. Hence , a healing period after
surgery of 3 to 4 months is
adequate for D1 and D2 bone.
A healing period of 5 to 6 months
is beneficial in D3 to D4 bone.

20. Elastic Modulus and Density
The elastic modulus of bone is more flexible than
titanium.
The difference between the two materials may create
microstrain conditions of pathologic overload and cause
implant failure.
When the stresses applied to the implant are low, the
microstrain difference between titanium and bone is
minimized and remains in the adapted window zone,
maintaining load-bearing lamellar bone at the interface

21. Misch et al. found the elastic modulus of the
trabecular bone in the human jaw to be different
for each bone density

22. when a stress is applied to an implant prosthesis in D1
bone, the Ti–D1 bone interface exhibits very small
microstrain difference.
In comparison, when the same amount of stress is applied
to an implant in D4 bone, the microstrain difference
between is greater and may be in the pathologic overload
zone

23. Bone Density and Bone–Implant
Contact Percentage
Misch noted that the bone density influences the
amount of bone in contact with the implant
surface.
The BIC percentage is significantly greater in
cortical bone than in trabecular bone.

24. D1 bone provides the highest percentage
of bone in contact with an endosteal
implant and may approximate more than
85% BIC.
 D2 bone, after initial healing, usually has
65% to 75% BIC.
D3 bone typically has 40% to 50% BIC
after initial healing
The bone–implant contact for D4 bone is
less than 30% after initial healing.

25. Bone stress
Crestal bone loss after loading may occur
from excess stress at the implant–bone
interface.
A range of marginal bone loss has been
observed in implants in different bone
densities with similar load conditions.
Tada et al. evaluated the three-dimensional
changes around different length implants in
different bone qualities

27. Since these variables cannot be eliminated
relative to bone density, the treatment
plans - including
implant number,
size, and
design should be modified to achieve a
successful prosthesis.

28. Studies Supporting Progressive
Loading
Many studies were done to assess the pros and
cons of progressive loading one such clinical
assessment was done using 250 implants over a 2-
year period using a Periotest
Misch CE: Progressive bone loading. In Misch CE, editor:
Contemporary implant dentistry, St Louis, 1993, Mosby
This instrument evaluates the dampening effect of
implants, prostheses, and teeth, which is related
directly to mobility.

29. The Periotest values can range from −8 to +99.
A range of −8 to + 9 Periotest value is applicable
to a structure with an absence of clinical mobility.
The implants in D1 bone, after progressive loading, did
not improve statistically, although a −7 Periotest value
was recorded more often.
The implants in D2 bone exhibited a mean decrease of 1
Periotest value.
The implants in D3 bone had a slightly greater than 2
Periotest value decrease after progressive loading.
The greatest change was seen in D4 bone where the
mean decrease in Periotest value was almost 4 units.

30. Therefore, the poorer the bone density
-- D3 and D4 -- the more dramatic the
decrease in Periotest values –which
relates to mobility and density of bone
around the implant.

31. The implementation of progressive
loading is more critical for lesser bone
densities because they are several
times weaker than those with
significant cortical bone.

32. Parafunction, cantilevers, and other stress
magnifiers can increase the forces applied
to the prosthesis and their shear
components and cause bone microfracture
or microstrains in the pathologic zone
around the implant.
Progressive bone loading aims at
oincreasing the density of bone,
odecreasing the risk of implant–bone
failure, and
odecreasing crestal bone loss.

33. Progressive
Loading
Protocol

34. The concept of progressive loading
is to allow the bone to adapt to
increasing amounts of
biomechanical stress.
Hence, rather than immediately
loading the bone–implant interface,
methods to slowly increase the
stress over time are a benefit.

35. The progressive loading protocol uses a
cement-retained prosthesis when
implants are splinted together.
Because a screw retained splinted
restoration is not completely passive and
a torque force applied to a screw is
greater than a bite force, a traditional
screw-retained restoration cannot use
progressive loading to gradually load the
bone

36. A longer healing time between
stage I and stage II is suggested
when forces are greater or bone is
softer.
This time allows greater
mineralization of bone and a more
mature lamellar bone interface to
form next to the implants before the
load of the screws is applied to the
implant bodies

38. Time - Initial Healing
The ideal bone for implant prosthetic
support is lamellar bone.
Lamellar bone is highly organized but takes
about 1 year to mineralize completely after the
trauma induced by implant placement.
Woven bone is the fastest and first type of
bone to form around the implant interface;
however, it is mineralized only partly and
demonstrates an unorganized structure

39. At 16 weeks, the surrounding bone is only 70%
mineralized and still exhibits woven bone as a
component.
The percentage of bone mineralization and the type of
supporting bone influence whether a load to the
bone– implant interface is within its physiologic limits.
Four prosthodontic steps are suggested for the
reconstruction of a partially or completely edentulous
patient, with endosteal Implants & they are separated
by a period of time related to the bone density
observed at the initial time of surgery.

40. The four prosthetic steps are
(1) abutment insertion, preparation,
final impression and temporary (of the
esthetic zone);
(2) a metal try-in and new bite
registration;
(3) initial delivery of the prosthesis; and
(4) final evaluation of the restoration and
hygiene appointment

41. This schedule allows sufficient time for
mature lamellar, mineralized bone to develop
at the interface and increases the numbers of
trabeculae in direct contact and within the
network region of the implant

42. When the dentist uses multiple implants,
the weakest bone area determines the
gradual load protocol.
Hence, if the anterior maxilla and
posterior maxilla are restored together,
the posterior maxilla would determine
the initial healing period and the time
period between each prosthetic
appointment

43. Diet
During the initial healing phase, the
dentist instructs the patient to avoid
chewing in the area, especially when
the implants are placed in a one-stage
approach.
The implant connected to an abutment
for cement retention is at greater risk
of loading during mastication.

44. The patient is limited to a soft diet such as pasta and
fish, from the final impression stage until the initial
delivery of the final prosthesis
The masticatory force for this type of food is about 10 psi

45. After the initial delivery of the final prosthesis, the
patient may include meat in the diet, which requires
about 21 psi in bite force.
The final restoration can bear the greater force
without risk of fracture or uncementation

46. After the final evaluation appointment, the
patient may include raw vegetables, which
require an average 27 psi of force.
A normal diet is permitted only after
evaluation of the final prosthesis function,
occlusion, and proper cementation

47. Occlusal Material
During the initial steps, the implant has no occlusal
contact but at subsequent appointments, the dentist
uses acrylic as the occlusal material, with the benefit
of a lower impact force than metal or porcelain.
Either metal or porcelain can be used as the final
occlusal material.

48. If parafunction or cantilever length causes
concern relative to the amount of force on
the early implant–bone interface, the
dentist may extend the softer diet and
acrylic restoration phase several months.
In this way, the bone has a longer time to
mineralize and organize to accommodate
the higher forces.

49. Occlusion
No occlusal contacts are permitted during
initial healing (step 1).
The first transitional prosthesis is left out of
occlusion in partially edentulous patients
(step 2)
The occlusal contacts then are similar to
those of the final restoration for areas
supported by implants. However, no occlusal
contacts are made on cantilevers or offset
loads (step 3)

50. Prosthesis Design
The first transitional acrylic
restoration in partially edentulous
patients has no occlusal contact and
no cantilevers.
Its purpose is to splint the implants
together and reduce stress by the
mechanical advantage and to have
implants sustain masticatory forces
solely from chewing.

51. The second acrylic transitional restoration
has occlusal contacts placed over the
implants with occlusal tables similar to the
final restoration but with no cantilevers in
nonesthetic regions.
The final restoration has narrow occlusal
tables and cantilevers designed with occlusal
contacts following implant-protective
occlusion guidelines

52. Progressive
Loading
Phases

53. The dentist instructs the patient with a
posterior implant in a partially
edentulous arch not to wear any
removable restoration.
If anterior teeth are part of the
removable prosthesis, a 7-mm-
diameter hole is placed completely
through the partial denture framework
around each PME
so it will not load the implant.

54. In completely edentulous patients, the
tissue surface of the denture is
relieved at least 5 mm over and around
the implants and replaced by a tissue
conditioner.
The conditioner also is relieved a few
millimeters. The patient returns in 2
weeks for suture removal and to
replace the tissue conditioner with a
soft liner.

56. An abutment for cement retention is
inserted and torqued into the implant bodies

57. The final abutment for cement retention is
torqued into position after a radiograph
confirms its position.

58. The first transitional restoration is
cemented with temporary cement. It is
completely out of occlusion.

59. The laboratory technician fabricates a
metal framework that splints the
abutments together

60. A metal try-in evaluates the casting

61. A closed-mouth centric recording is
made over the metal framework.

62. The original transitional restoration is modified by
adding acrylic on the occlusal surface, and a heavy
bite force occlusal adjustment is made.

63. The final restoration is evaluated in the
mouth

64. A radiograph is made for baseline
evaluation of the prosthesis.

65. Completely Edentulous Patient Protocol
Before or during surgical phases, the dentist may
fabricate treatment prosthesis that restores the
patient to the proper occlusal vertical dimension
(OVD) and determines the correct tooth position for
the final prosthesis.
A clear template (0.008
inch) is made over the
patient’s denture and
trimmed to the soft tissue
borders.
This acts as a
customized impression
tray and records a bite
registration to the
opposing arch

66. A two-piece transfer coping engages the hexagon of the implant
body.
A closed-tray impression is made with the customized impression
tray over these implant body transfers

67. The customized impression tray with the occlusal bite
registration in centric relation occlusion

68. The impression transfer
copings are attached to
the implant bodies,
poured, and mounted to
the opposing arch with
the customized
impression tray.
The final abutments are
selected and prepared
for parallelism and tooth
position.

69. A transitional restoration is made
over the prepared implant
abutments.
The transitional prosthesis does not
have a cantilever.
The laboratory-prepared
abutments are positioned
over the anti-rotation
component of the implant
body and are secured
with an abutment screw
at 30 N-cm of torque.

70. The first transitional restoration,
without cantilever, is delivered.
The patient is instructed to limit
the diet to only soft food.
At the metal try-in appointment, the
framework of the prosthesis is evaluated.
White wax is used to evaluate the
incisal edge position.
Acrylic posterior indexes are used to
evaluate the occlusal vertical dimension
and centric occlusal registration

71. The final
restoration is
delivered to the
patient.

72. The progressive bone loading approach provides the
environment favorable for the development of load-
bearing bone at the implant interface in two ways:
• the development of an extended time period before the
introduction of full-magnitude functional forces and
• the limitation of these forces to vertical forces as the
dominant component.
This gradual increase in loads permits the
adaptation of the bone , increase in bone density
and improved crestal bone conditions around the
implant compared with a more sudden loading
protocol results in increased implant survival and
less crestal bone loss.

76. The Immediate loading of dental implants clearly
represents the change in dogma. To load the
implant immediately or not to load is indeed the
question today and the rationale that goes with the
protocol which warrants discussion.

79. The preloading or stretching the screw places the components
under enough tension to create elongation of the material within its
elastic limit. Preloading may reduce screw loosening.

80. As a result the components stretch and maintain fixation in spite of
vibration and external forces. The elongation of metal is related to the
modulus of elasticity, which is dependent on the type of material, its
width, design, and the amount of stress applied per area.

81. Thus a gold screw exhibits greater elongation but lower
yield strength than a screw made of titanium alloy. A
prosthesis screw may exhibit a torsional ductile fracture at
16.5 N-cm Vs 40 N-cm for an abutment screw of different
material and size.

82. The material the screw is made from (eg. Titanium alloy
or gold) has a specific modulus of elasticity. The plastic
deformation or permanent distortion of the screw is the
end point of the elasticity modulus. When the screw is
stretched with a force 75% of its elastic length, it is able
to better resist vibration and screw loosening.

83. In order to stretch the screw, a torque wrench is
necessary, although not completely accurate. Even an
experienced clinician is unable to determine the amount
of correct torque on the screw by tactile sense only.

84. A screw may be described to permit more preload on
the components.

85. The after-loading of implants is achieved by means of
prosthesis brought into occlusion.

87. As a result of unique physiological mechanisms, bone serves two
antagonistic functions:
structural support and calcium metabolism.
The strength of a bone (quantity, quality and distribution of osseous
tissue) is directly related to loading.

88. As an energy conservation measure, bone that is not adequately loaded
is resorbed, and the skeletal system continuously adapts to achieve
optimal strength with minimal mass. The delicate structural balance is
further challenged by metabolic function.

89. An adequate reserve of osseous tissue must be maintained to provide a
continuous stream of ionic calcium without compromising structural
integrity. To provide for a variety of conflicting demands, the skeleton
has evolved structural and metabolic fractions.

91. Osteopenia (inadequate bone mass) is a common
clinical problem. It may be due to functional atrophy
and/or negative calcium balance.
Prospective oral implant patients are likely to present
with localized and systemic skeletal problems for three
reasons:

92. Bone in edentulous areas is usually atrophic.
Metabolic bone disease is prevalent in middle-aged and
older adults.
Integrated implants are often indicated for patients with
a history of severe bone loss.

93. The clinical success and durability of endosteal dental implants as load
bearing abutments are controlled largely by the mechanical setting in
which they function. The treatment plan is responsible for the design,
number, and position of the implant.

95. Unique mechanisms of bone adaptation have evolved to maintain
structural integrity, repair fatigue damage, and provide a continuous
source of metabolic calcium.

97. Modeling involves individual uncoupled sites of bone formation or
resorption that change the shape or form of a bone. This is the principal
mechanism for adapting osseous structure to functional loading.

98. Remodeling is the mechanism of bone turnover. It involves coupled
sequences of cell activation (A), bone resorption (R) and bone formation
(F). The duration of the ARF remodeling cycle (sigma) is about 4 months
in humans.

99. Modeling is the principal means of skeletal adaptation to functional and
therapeutic loads. Relatively modest changes in the distribution of
osseous tissue along cortical bone surfaces can dramatically change the
overall load bearing capability.

100. By a mechanism of focused bone resorption and
formation events, trabeculae can form, reorient and
change in size as a result of "micromodelling" to resist
functional loads optimally.

101. A good example of this process is the network of
secondary tissues that forms in the marrow cavity to
support an integrated fixture.

103. Under most circumstances, cortical bone remodels at a rate of about 2-
10% per year. Since only a portion of the cortex is in the metabolic
fraction. The remodeling rate for cortical bone is usually 3-10 times less
than for adjacent trabecular bone (metabolic fraction).

104. This complex interaction involves not only biomaterial and
biocompatibility issues, but also the alteration of the mechanical
environment that occurs when placement of an implant disturbs the
normal physiologic distribution of forces, fluids, and cell communication.

105. In 1977, Branemark & coworkers published the first
long-term follow up study on dental implants, thus
providing the scientific foundation of today's implant
treatment. The successful use of jaw bone anchored
(osseointegrated) titanium dental implants to retain
prosthetic constructions in the rehabilitation of the
edentulous and partially edentulous patients has
been well documented in several publications.

106. The original two-stage surgical protocol using a two-
piece implant pillar was applied. The main reasons for
this approach have been to
Minimize the risk of infection
Prevent apical down growth of mucosal epithelium,
and
Minimize the risk of undue early loading during the
initial healing period.

107. In addition, a stress-free healing period of 3 to 6 months
before the mucosa piercing abutments are placed and
the supra-construction is connected to the implants was
emphasized to predict a successful treatment outcome.
Such a stress free period was even considered to be an
ultimate prerequisite to achieve proper
osseointegration.

108. In other words, early stress on the implants was thought
to jeopardize the osseointegration process.

109. Over the years, however, the high level of
predictability in implant therapy has resulted in a re-
evaluation of the original Branemark protocol for
implant placement. Schroeder & coworkers were the
first to show the possibility to achieve demonstrated
successful clinical treatment outcome using the one
stage surgical protocol with the Branemark system.

110. Similar successful clinical treatment outcomes, in the
edentulous as well as the partially edentulous situation,
have been reported using one-piece implants (ITI,
Straumann) placed according to the original one-stage
surgical protocol.

111. In several clinical studies the original dentures most
often were adjusted and relined by a soft tissue
conditioner 10 to 12 days following implant
placement to minimize unfavorable functional
loading, i.e., undue early loading. However, it has to
be anticipated that implants placed according to a
one-stage surgical procedure to some extent will be
directly and unpredictably loaded during function in
the initial healing period via the adjusted and relined
denture.

112. Furthermore, such loading might be unfavorable for the
implants, as the deformation pattern of complete
denture base material would cause micromovements.
In other words, "an initial and direct loading of implants
piercing the mucosa via the adjusted and relined
denture obviously does not jeopardize a proper
osseointegration of the fixtures".

113. Such a statement is in agreement with clinical
observations reported by Henry & Rosenberg, who
concluded that “controlled immediate loading” of
adequately installed, non-submerged implants, by
reinsertion of a modified denture, does not appear to
jeopardize the process of osseointegration in the
anterior mandible.

114. " Similar observations were reported by Cooper et al.
Furthermore, Becker et al concluded that" one-step
Branemark implants may be considered a viable
alternative to two-step implants."

115. In former days, it was postulated "too-early loading
of an implant leads to interfacial formation of fibrous
tissue instead of bone".
Others claimed "controlled immediate loading does
not appear to jeopardize the process of
osseointegration".
Today's knowledge indicates that the degree of
micromotion at the bone-implant interface during the
initial healing phase and it may be not premature
loading.

116. Premature loading
leads to implant
movement
The end result
“Soft tissue
interface”
“Bony interface”

117. As favorable loading conditions of tooth abutments are
obtained via a rigid fixed appliance, it is reasonable to
believe that successful treatment outcomes can be
reached also when rigid fixed supraconstructions are
connected to implants soon after implant placement.

118. To reduce the period during which the individual
implants are exposed to direct and unpredictable
loading, splinting of the individual implants through a
rigid fixed device will most certainly decrease the
micromotion at the bone-implant interface, thus
facilitating proper bone healing (osseointegration).

120. Based on the available information, Randow et al
believed it to be of interest to compare the
rehabilitation of edentulous mandibles by fixed
supraconstructions connected to implants placed
according to either an early loaded onestage surgical
procedure or the original two-stage concept, with the
working hypothesis that there are no differences
between the two methods concerning the treatment
outcome.

121. A total of 88 implants (16 patients) were placed
according to the one-stage protocol and loaded via a
fixed appliance within 20 days. The implants placed
according to the original protocol were loaded about 4
months following placement. At the time of delivery of
the fixed appliances, all patients were radiographically
examined, an examination that was repeated at the 18-
month follow-up.

122. The analysis of the radiographs revealed that during the
18-month observation period the mean loss of bone
support amounted to about 0.5 mm around the
implants, irrespective of early loading. All implants were
at all observation intervals found to be clinically stable.

123. The authors concluded that it is “possible to successfully
load titanium dental implants immediately following
installation via a permanent fixed rigid cross-arch
supraconstruction”. However, such a treatment
approach has so far to be strictly limited to the inter-
foramina area of the edentulous mandible.

124. Schnitman and coworkers reported on 63 Branemark
implants placed in 10 patients. Of these 63 implants, 28
were placed and "immediately loaded to support an
interim fixed bridge." The remaining 35 implants were
placed according to the 'original two-stage protocol,
osseointegrated properly, and are still in function. Of
the 28 implants immediately loaded, four failed.

125. In other words, the survival rate for the immediately
loaded implants was found to be about 85%.

127. Early implant failure
Early crestal bone loss
Intermediate to late implant failure
Intermediate to late implant bone loss
Screw loosening (abutment and prosthesis coping)
Uncemented restoration
Component fracture
Porcelain fracture
Prosthesis fracture
Periimplant disease (from bone loss)

129. The surgical and prosthetic protocols for the
development of a predictable direct bone-to-implant
interface with root-form implants were developed and
reported by Branemark et al.

130. About 25 years ago, Branemark et al (1977)
published the first long-term follow-up on oral
implant, providing the scientific foundation of
modern dental implantology. The predictability of
implant integration according to Branemark and
collaborators was obtained by adherence to a strict
surgical and prosthodontic protocol. One of the most
emphasized requirements was a stress-free healing
period of 3-6 months, making implant treatment
lengthy.

131. Presently however, early and immediate loading
protocols are reported by an enhancing number of
clinical (Chiapasco et al 1997, Schnitman et al 1997,
Tarnow et al 1997) and experimental publications.

132. Following their 10-year clinical experience,
recommendations ensuring durable osseointegration
of dental implants were set.
The most important were:

133.  Use of sterile conditions as "in a fully equipped operatory"
 Use a mucobuccal incision and avoid a crestal one
 Use of an atraumatic surgery involving low-speed drilling
 Use of a biocompatible material i.e. titanium
 Use of titanium ancillary
 Use of a 2-stage procedure
 Use of a stress-free healing period of 3-6 months before
loading
 Avoid X-radiographs before the end of the healing period
 Use of acrylic occlusal contact surfaces

134. Early loading was identified as a detrimental factor for
osseointegration' by Branemark et al During 'the
course of their clinical trial (Branemark et al 1977).
BUT TODAY THE SCENARIO HAS CAHNGED TO
LOADING AND IMMEDIATE LOADING.

137. Time interval
Diet
Occlusal material
Occlusal contacts
Prosthesis design

138. The masticatory force for soft food is about 10 psi. This
diet not only minimizes the masticatory force on the
implants but also decreases the risk of temporary
restoration fracture or partially decemented restoration.
Either of these consequences can overload an implant
and cause unwanted complications.

139. The diet protocol should not be overlooked during the
restorative procedure because most dentists have
observed the fracture of acrylic prostheses with harder
foods and greater occurrence of decemented
restorations when they ignore type of diet during the
transitional prosthesis stages.

140. After the initial delivery of the final prosthesis,
the patient may include meat in the diet, which
requires, about 21 psi in bite force. The final restoration
can bear the greater force without risk or fracture or
decementation.

141. After the final evaluation appointment, the patient may
include raw vegetables, which require an average 27 psi
of force. A normal diet is permitted only evaluation of
the final prosthesis function, occlusion, and proper
cementation.

142. Occlusal material:
The occlusal material may be varied to load
the bone-to-implant interface gradually. During the
initial steps, the implant has no occlusal material over
it. At subsequent appointments, the dentist chooses
acrylic as the occlusal material, with the benefit of a
lower implant force than metal or porcelain.

143. Either metal or porcelain can be used as the final
occlusal material. If para function or cantilever length
cause concern relative to the amount of force on the
early implant bone interface, the dentist may extend the
softer diet and acrylic restoration phase for several
months. In this way, the bone has a longer time to
mineralize and organize to accommodate the higher
forces.

144. Occlusion:
The dentist gradually intensifies the occlusal
contacts during prosthesis fabrication. No occlusal
contacts are permitted during initial healing. The first
transitional prosthesis is left out of occlusion in
partially edentulous patients.

145. The occlusal contacts then are similar to those of the
final restoration for areas supported by implants. The
occlusal contacts of the final restoration follow the
implant-protective occlusion concepts.

146. Prosthesis design:
During initial healing, the dentist attempts to
avoid any load on the implants, including soft tissue
loads. The first transitional acrylic restoration in partially
edentulous patients has no occlusal contacts.

147. Its purpose is to splint the implants together, to reduce
stress by the mechanical advantage, and to have
implants sustain masticatory forces solely from chewing.
In the second acrylic transitional restoration, occlusal
contacts are placed on the implants with occlusal tables
similar to the final restoration but with no cantilevers in
nonesthetic regions