Loading of implants/ General orthodontics

WWW.INDIANDENTALACADEMY.COM
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

• Introduction
• Terminologies
• Rationale for implant immediate loading
• Histologic evaluation – Short term
• Long term
• Indication for immediate loading
• Contraindications for immediate loading
• Immediate occlusal loading- Factors that reduce risk

• Loading protocols for completely edentulous arches
• Loading protocols for posterior maxillary and
mandibular arches
• Loading protocols for esthetic zone
• Progressive loading
• Advantages
• Disadvantages
• Conclusion
• References

• Patients levels of knowledge and expectations for
treatment with dental implants have increased
tremendously
• Historically, two-stage surgical protocol was
proposed.
• The introduction of new implant surfaces has made it
possible to modify loading protocols

TERMINOLOGY
Loading
of
implants
Conventional
loading
Immediate
loading
Early loading
Delayed
loading
Immediate
restoration
Int J Oral Maxillofac Implant
2004; 19

Immediate
occlusal
loading
Early
occlusal
loading
Delayed
occlusal
loading
Progressive
loading
Non
functional
immediate
restoration
Non
functional
early
restoration
Carl Misch 3 rd
edition

Lamellar bone Woven bone

• Bone interface is stronger on the day of implant
placement
• As a result of surgical trauma lamellar bone becomes
woven bone of repair
• Weakest bone- implant interface at 3- 6weeks
• Buchs et al (2001) – immediately loaded implant
failure occurred between 3- 5 weeks
• Decrease surgical trauma and bone remodeling
process.

• Causes of trauma
• Thermal injury
• Microfracture of bone
• Amount of heat generated
• Drill design
• Speed
• Drill sharpness

• Irrigation
• Amount of bone prepared
• Variation of cortical thickness
• Bone cell death at 40˚ C ( Eriksson and
Albrektsson,1983)

• Self tapping implant – greater bone remodeling
• Insertion torque within 45 N-cm
• Rationale of immediate loading is not only to reduce
the risk of fibrous tissue formation but also to
minimize woven bone formation and promote
lamellar bone.

• The initial histologic evaluation
of bone implant interface have
reported favorable bone quality
around implant
• Romanos et al, 2001l
demonstrated no statistically
significant difference between
immediate and delayed loaded
implants.
• Suzuki et al, 2008
demonstrated higher bone
implant interface in immediately
loaded implant than in delayed
loaded implant.

• No statistically significant difference were detected in
bone implant interface after 8 months
• Less marrow spaces and more compact bone
• Studies also have demonstrated greater bone
contact in immediately loaded implants after 9
months.

• Patients can not tolerate removable prosthesis
• Uncomfortable wearing dentures
• Do not wish to wait for 3 or more months

• The suggested contraindications, in general, for
consideration of an immediate loading protocol
include the following:
• Severe metabolic disease
• Inadequate bone volume for correct implant
placement
• Very poor bone density (D4)
• Severe parafunction (eg, bruxing, clenching,
tongue thrust)
• Noncompliant patient types (eg, diet limitations,
gum chewing)
• Smokers

• Bone microstrain
• Surgical technique
• Initial implant stability
• Quality and quantity of bone
• Occlusion

• Bone Microstrain
• Microstrain level 100times less than ultimate
strength of bone may trigger cellular response.
• Frost developed a microstrain language for bone
based on biological response at different
microstrain level.

• Titanium has higher modulus of
elasticity than bone
• Microstrain difference between
bone and titanium in frost
microstrain zone at 50 units is
disuse atrophy
• When difference is 50 to 2500
units – ideal loading zone
• 2500- 4000 units the zone is mild
overload
• More than 4000 units it is
pathologic overloadWWW.INDIANDENTALACADEMY.COM

• Microstrain can be reduced by increasing the
functional surface area of bone implant interface.
• Increased surface area
• Implant number
• Implant size
• Implant design
• Implant body surface condition

• Factors affecting force to prosthesis
• Patient condition
• Implant position
• Direction of occlusal loading.

• Immediate loading reports with lowest survival rate
corresponds to fewer implants loaded
• Increases retention
• Decreases number of pontics
• Reduces fracture of transitional prosthesis
• More implants used for maxilla than mandible

• 3mm increase in length improves surface area by
20%
• No benefit at crestal bone interface
• Improves initial stability
• Length is more relevant for immediate loading
• 1mm increase in width increases surface area by 30
%
• Wider implant provide greater area of bone contact
at crest of ridge
• Bone augmentation done when required

• Implant body design should be more
specific for immediate loading.
• The following would be the design
principles, one would want to achieve
through an implant design
a) Gain initial stability
b) Incorporate design factors,
that would diminish the effect of
shear forces
c) Design features that may
stimulate bone formation and
facilitate bone healing.

• A tapered design presents some
disadvantage for immediate load
application.
• The implant doesn’t engage the
bone physically until the
implant is seated completely
into the bone site.
• Tapered implant has less
overall surface area than
parallel wall threaded implant.
• May have less thread depth
near the apical portion of
implant.
• Less likely to engage lateral
cortical plate in apical half of
implant.
Tapered
implants
Parallel wall
implantsWWW.INDIANDENTALACADEMY.COM

V shaped
Square thread
Buttress thread

• Thread depth,
• Thread thickness,
• Thread face angle, and
• Thread pitch

• Threads have been incorporated into implants to
improve initial stability
• Strain is more concentrated in the area where bone
contacts the crest of the thread and the strain
decreased from the crest to the root of the thread.

• Square thread design with a flank angle of 3 degree
decreases the shear force and increases the
compressive load.
• V thread design show 10 times greater stress
• The surface area of threaded implant can be
increased by
• Greater no of threads
• Lesser distance between the threads
• Increased thread depth

• It may affect the
• Rate of bone contact,
• Lamellar bone formation and
• Percentage of bone contact.
• It may be that although surface
texturing of implants do not directly
contribute to initial implant stability it
may reduce the risk of stability loss
and consequently facilitating wound
healing.

• Patient factor
• Increased occlusal load increases risk of failure
in immediate loaded implant.
• Parafunction habits
• Occlusal load direction
• Axial load maintains more lamellar bone and has
lower remodeling rate compared to offset load
• Eliminate posterior cantilever in immediate loaded
implants

• Implant position
• More important factors for completely edentulous
arches
• Splinted arch position
• Mandible divided into three section
• Maxilla divided into five section
• Occlusal contact
• Only anterior contact in transitional prosthesis
• Diet
• Soft

• Modulus of elasticity related to bone quality
• BIC is less for less dense bone
• Remodeling rate is less for cortical bone than
cancellous bone
• Immediate loading of implants at bone augmented
area is at higher risk

• To accurately asses the impact of loading protocols
• Maxillary and mandibular protocol
• Fixed or removable rehabilitation
• Implants placed in healed sites or sockets not
yet healed
• Machined or rough surface implants

• Immediately loaded mandibular overdenture is at
least risk of occlusal overload
• Success rate of 88 to 97 %
• Guidelines for overdenture
• Completely edentulous mandibular arch
• Opposing maxillary denture

• Abundant to moderate bone height and width
• At least 12mm prosthetic space
• At least 4 implants
• Screw type implants
• Minimum cantilever
• Sleep without overdenture
• Parafunctional habits- contraindication

• Guidelines for fixed prosthesis
• 8 more implants in maxillary arch and 5 or more in
mandibular arch
• 10mm in length and 4 mm in width
• Thread design and rough surface implants
• Mandible divided in 3 section
• Maxilla divided in 5 section
• Only anterior teeth contact
• No cantilever in transitional prosthesis
• Soft diet

• Load the implant on the day
of surgeryOption
1
• Make impression at surgery,
at suture removal transitional
prosthesis delivered.
Option
2

• Most reports suggest immediate restoration rather
than full occlusal loading
• Transitional retsoration mainly for esthetics
• No occlusal contact
• Non functional immediate teeth concept is
suggested.

• Advantages of non functional immediate tooth
concept
• Esthetic restoration replaces missing teeth
• Implants splinted together
• Emergence profile created
• Soft tissue is mature at final prosthesis
• Decrease risk of biomechanical overload

• Disadvantage of Non functional immediate teeth
• Increased overload compared to submerged
implants
• No evaluation of crestal bone directly
• Parafunction from foreign habits may cause
trauma
• Impression material or acrylic may get entrapped

• Single tooth implant considered for immediate
restoration when
• Natural tooth require extraction
• Esthetic zone
• The soft tissue drape is in ideal condition
• Bony housing around the implant is intact
including the facial plate.

One piece implant Implant -
abutment

• Gradual increase in load during prosthetic fabrication
stimulates an increase in density
• Pierazzini demonstrated development of dense
trabeculae around progressively loaded implants in
animals.
• Implementation of progressive loading is more critical
in lesser bone densities as they are several times
weaker than the cortical bone.

• Time
• Two surgical appointment between implant
surgery and stage II are separated by 4-8 wks
• Prosthetic appointment during which implants are
sequentially load are separated by 2- 4 wks
• Diet
• Controlled to prevent overloading
• Soft diet
• Normal diet is permitted only after final prosthesis
function, occlusion and cementation is evaluated.

• Occlusal material
• Acrylic – transitional prosthesis
• Metal/ porcelain- final prosthesis
• Occlusion
• Gradually intensified
• Prosthetic design
• Avoid load on implants during initial healing
• Transitional prosthesis- splinting of implants

• Implants placed
• After 1 – 4 wks, impression made for transitional
prosthesis
• Transitional prosthesis completely out of occlusion
• Impression for final prosthesis
• Metal try in
• Provisional cementation of final prosthesis
• Final evaluation and cementation of prosthesis

• A second stage surgery is eliminated.
• This saves patient pain and suffering
• Removable prosthesis not required
• Soft tissue is allowed to mature
• Implants are splinted together during healing which is
biomechanically superior.

• Risk of failure
• More number of implants are placed making
treatment expensive

• The delayed loading protocol is being evaluated for
more than 30 years.
• However in some patient condition this may cause
psychological, social or speech problems. Immediate
loading after implant surgery is the alternative of
these problems. A benefit/risk ratio should always be
weighed prior to doing such a procedure.

• Contemporary Implant dentistry – Carl E Misch 2nd
and 3 rd edition
• International journal of oral maxillofacilal implant ,
2004; 19: 109-113
• International journal of oral maxillofacilal implant,
2004; 19: 75- 107
2009; 24: 158-168
2009; 24: 132- 146

2009; 24 169 – 179
2009; 24: 147-157
• Australian dental journal, 2008; 53(suppl): S69-S81.
• Stomatologija, Baltic dental and maxillofacial
journal,2004; 6: 51-54.

For more details please visit
www.indiandentalacademy.com

Loading of implants/ General orthodontics

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Loading of implants/ General orthodontics

Similar to Loading of implants/ General orthodontics (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Loading of implants/ General orthodontics