Dental and Maxillofacial Implants

PRESENTED BY:
DR. VENU SAMEERA PANTHAGADA
ASSISTANT PROFESSOR
DEPT OF MAXILLOFACIAL SURGERY
GDC, VIJAYAWADA.
Dental and Maxillofacial
Implants

 Successful implant treatment is dependent on a coordinated approach combining
careful treatment planning ,meticulous surgical technique and precise prosthetic
restoration.
 Typical implant team is composed of a trained surgeon,who places the implant ,
a trained prosthetic dentist, who designs and places the prosthetic replacement and
an experienced dental lab technician who creates the prosthetic restoration.
Introduction To Multidisciplinary Approach:

 1.Based on implant design
 2.Based on attachment mechanism
 3.Based on macroscopic body design
 4.Based on the surface of the implant
 5.Based on the type of the material
CLASSIFICATION OF DENTAL IMPLANTS

 A device which is placed into the alveolar bone and/or basal bone of the mandible
or maxilla
 Transect only one cortical plate
1.ENDOSTEAL IMPLANT

 It consist of thin plates in the form of blade embedded into the bone
a) BLADE IMPLANT

 Horse shoe shaped stainless steel device
 Inserted into the mandible from one retromolar pad to the other
 It passes through the anterior symphysis area
b) RAMUS FRAME IMPLANT

 Designed to mimic the shape of the tooth
 For directional load distribution
c) ROOT FORM IMPLANT

 Placed directly beneath the periosteum overlying the bony cortex
2. SUBPERIOSTEAL IMPLANT

 Inserted into the oral mucosa
 Mucosa is used as attachment site for the metal inserts
4.INTRAMUCOSAL IMPLANTS

CLASSIFICATION BASED ON ATTACHMENT MECHANISM OF THE
IMPLANT

CLASSIFICATION BASED ON MACROSCOPIC BODY DESIGN OF
THE IMPLANT

 FIBROINTEGRATION
 Proposed by Dr.Charles Wiess
 Complete encapsulation of the implant with soft tissues
 Soft tissue interface could resemble the highly vascular periodontal fibers of natural dentition.
 OSSEO-INTEGRATION
 Direct contact between the bone and the surface of the loaded implant
 Described by BRANEMARK
 Bio active material that stimulate the formation of bone can also be used

 in the form of cylinder
 Depends on coating or surface condition to provide microscopic retention and
bonding to the bone
 Pushed or tapped into a prepared bone site
 Straight, tapered or conical
CYLINDRICAL DENTAL IMPLANTS

 The surface of the implant is threaded, to increase the surface area of the
implant
 This results in distribution of forces over a greater peri-implant bone volume
THREADED DENTAL IMPLANTS

 Plateau shaped implant with sloping shoulder
PLATEAU- DENTAL IMPLANTS

 The implants of inert micro porous membrane material (mixture of cellulose
acetate ) in intimate contact with and supported by the layer of perforated
metallic sheet material (pure titanium)
PERFORATED DENTAL IMPLANTS

 They are of circular cross section without vent or hollow in the body
SOLID DENTAL IMPLANTS

 It is hydroxy apetite coated cylinder implant patented vertical groove connecting
to the apical vents were designed to facilitate seating and allow bone ingrowth to
prevent rotation
VENTED DENTAL IMPLANTS

 Hollow design in the apical portion
 Systematically arranged perforations on the sides of the implant
 Increased anchoring surface
HOLLOW DENTAL IMPLANTS

 SMOOTH SURFACE IMPLANT :
 It has a very smooth surface
 To prevent microbial plaque retention, smooth
surface is essential
 MACHINED SURFACE IMPLANTS:
 For the purpose of better anchorage of implant to
the bone, the surface of the implant is machined
CLASSIFICATION BASED ON THE SURFACE OF THE IMPLANT

 TEXTURED SURFACE IMPLANT:
 The implants of increasing surface roughness of the area
to which bone can bond

 COATED SURFACE IMPLANT
 The implant surface is covered with a porous coating
 The materials used for coating are
titanium
hydroxy apatite

CLASSIFICATION BASED ON THE IMPLANT MATERIAL

IMPLANT COMPONENTS:
 IMPLANT BODY OR FIXTURE
 COVER OR HEALING SCREW
 HEALING OR INTERIM ABUTMENT
 IMPRESSON COPING
 IMPLANT ANALOG OR REPLICA
 IMPLANT ABUTMENT
 PROSTHESIS RETAINING SCREW

Implant Fixture Or Body:
 This is the implant component placed with
in the bone during the first phase of
surgery.
 Most of them are rootform implants and
have an external threaded design to
maximize the implant stability and the
process of osseointegration.
 Available with antirotational feature
located internally or externally.

Cover Screw Or Healing Screw:
 After the placement of implant body
in two stage surgical procedure, prior
to the suturing, the implant body is
sealed at its platform with a low
profile intra implant cover screw.
 Cover screw is fully seated on the
implant platform prior to suturing to
prevent bone from growing between
screw and the implant.

Healing Or Interim Abutment:
 Healing abutments are dome shaped intraimplant
screws, which provide permucosal access to implant
platform.
 Abutments can be parallel walled or tapered and
range in height from 2mm to 10mm.
 It should project 2mm superior to the height of
gingival tissue.
 Tapered healing abutment is used to help shape soft
tissue to a more appropriate emergence for the
crown.
 It is important to allow for sufficient healing of soft
tissue prior to making any impression for the final
prosthetics.

Impression Coping:
 Impression coping facilitates the transfer of
intraoral loaction of implant to the same position
on the laboratory cast.
 Impression transfer can be either closed tray
transfer or open tray transfer.
 closed tray technique captures the index of the
impression coping and after the impression is
removed from the mouth , the coping is
unscrewed from the implant and placed along
with implant analog back into impression.
 Open tray transfer uses a specific impression
coping that is designed to emerge through the
impression tray. When the impression is ready to
be removed from mouth, impression coping is
unscrewed and pulled out in impression.

Implant Analog
 Implant analogs are manufactured to
replicate exactly the top of the implant
fixture or abutment in the laboratory
cast.
 Both are screwed directly in to the
impression coping.
 Imprression coping or analog
component is then placed back in to
the impression .
 And the impression is ready to pour .

Implant Abutment:
 Abutment is the portion of the implant that
supports or retains a prosthesis or implant
superstructure.
 A superstructure is defined as metal or zirconia
framework that attaches to either implant
platform or implant abutment that retains
prosthesis.
 Abutments can be divided in to three
categories.
 Screw retained
 Cement retained
 Prefabricated

Prosthesis Retaining Screw:
 Prosthesis retaining screws are
intended to attach prosthetic
abutments , screw retained crowns, or
frameworks to the implant ficture.
 They are generally made of titanium
and titanium alloy .
 These screws are tightened by torque
wrench and torque value ranges from
10 to 40 Ncm.

 INITIAL OBSERVATION AND PATIENT INTRODUCTION
 CHIEF COMPLAINT
 MEDICAL HISTORY AND MEDICAL RISK ASSESMENT
 DENTAL HISTORY
 INTRAORAL EXAMINATION
 DIAGNOSTIC CASTS AND PHOTOGRAPHS
 RADIOGRAPHIC EXAMINATION
 PROSTHETIC CONSIDERATIONS IN IMPLANT TREATMENT PLANNING
 SURGICAL TREATMENT PLANNING CONSIDERATIONS
 FINAL TREATMENT PLANNING
PREOPERATIVE ASSESMENT AND TREATMENT PLANNING:

 At the first meeting with the patient,
 Experienced clinician begins observing the patients physicality , physique,
complexion, hands, eyes, facial features, voice , posture, personality.
 The same initial charecteristics will continue to be observed throughout the
consultation.
Initial Observations And Treatment Planning:

 The patient chief complaint is a statement in his or her own words that conveys the
percieved problem, concerns , expectations,.
 Clinician must assess how realistic the patients expectations are.
 Is the patient looking strictly for a functional replacement or is there a strong
esthetic expectation.
Chief Complaint:

Medical History And Medical Asessment:
 A thorough medical history is required and documented for every dental
patient.
 Absolute contraindications to implant placement based on surgical and
anesthetic risks are limited primarily to patients who are acutely ill and those
with uncontrolled metabolic disease.
 Often these contraindications are limited in duration, once the illness resolves
or the metabolic disease is controlled , the patient becomes a good candidate
for implant therapy.
 Relative contraindications are concerned with medical conditions that affect
bone metabolism or the patients ability to heal.
 These include diabetes , osteoporosis , immune comprimise condtins like HIV,
medications like bisphosphonates and medical treatments like chemotherapy
and irradiation of head and neck

 Some psychological and mental
conditions could be considered absolute
or relative contraindications, depending
on their severity .
 Eg: schizophrenia , paranoia, neorosis,
hysteria and patients with unrealistic
expectations .
 Certain habits such as smoking, tobocco
use, substance use, and parafunctional
habits like bruxism and clinching must
be scrutinized as potential
contraindication.
 Smoking in particular is a risk factor
resulting in decreased long term stbility
and retention of implants.

 The clinician seeks information regarding patients past experiences with restorative
dentistry , periodontics, oral surgery , endodontics, orthodontics and prosthetics.
 By understanding the patients prior dental history , the clinician can gain insight into
patients potential as a candidate for implant therapy.
Dental History:

Intraoral Examination
 The implant focussed intraoral examination should address the restorative or
structural integrity of existing teeth, existing prosthetics, vestibular depths,
palatal depths , edentulous ridge topography, periodontal status, oral lesions,
infections, occlusion, orthodontic assessment, jaw relationships, interarch
space, maximum opening, parafunctional habits and oral hygiene.
 Specific attention should be paid to edentulous ridge anatomy and soft tissue
morphology.
 The height and width of the ridges are evaluated visually followed by palpation
to determine undercuts or bony defects.
 Consider the health of soft tissue around exixting teeth, the edentulous areas
and any previosly placed implant.

 Soft tissue is examined for zones of
keratinization i,e., quantity and location,
clinical biotype i,e.,thin , moderate,
thick,,. Redundency , mobility , and
pathology.
 Clinical inspection of soft tissue even
requres radiographic examination if soft
tissue is fibrous.
 Thick fibrous tissue can often mask
underlying bony structure.
 Clinician should also evaluate surgical
ergonomics , that is how wide can
patient open mouth , how reselient the
cheeks are , the size of the tongue,
perioal musculature.

Diagnostic Casts And Photographs:
 Mounted study models as well as
intraoral and extraoral photographs
complete the record collection process.
 Elements that can be evaluated from
accurately mounted modela are:
 Occlusal relationship
 Arch relationship- interarch space, form ,
anatomy, symmetry
 Curve of wilson and curve of spee
 Tooth morphology, wear facets
 Measurements for planning implant
locations

 Intraoral photographs allow visual
evaluation of patient soft tissue.
 Extraoral photographs provide:
 Facial form
 Facial symmetry
 Smile line
 Incisal edge display
 Buccal cooridor display

Radiographic Examination:
 Area of study radiographically include:
 (1) location of vital structures eg: mandibular canal its
anterior loop and its anetrior extension, mental foramen
, incisive foramen , maxillary sinus and nasal cavity.
 (2) bone height , bone density, bone trabeculation
 (3) root proximity and angulation of existing tooth
 (4) evaualtion of cortical bone
 (5) sinus health
 (6)crosssectional topography and angulation
 (7) skeletal classification

 Critical measurements specific to
implant placement include:
 Atleast 1mm inferior to the floor of
the maxillary sinuses and nasal floor
 Incisive canal ( maxillary midline
implant placement ) to be avoided
 5mm anterior to mental foramen
 2mm superior to mandibular canal
 3mm from adjacent implants
 1.5mm from roots of adjacent teeth

 Patients occlusion need to be examined .
 Clinician must evaluate the occlusal scheme eg: cuspid protected or group function
 Occlusion can be classified eg: class 1 class 2 class 3
 Open bite, deep bite, cross bite need to be assessed.
 Occlusal plane , curve of spee , curve of wilson to be evaluated.
Prosthetic Considerations In Implant Treatment Planning:

 Evalauation of interarch space is critical in both the
partially and totally edentulous patient.
 The interarch space determines spatial limitations
or an opportunity for specific prosthetic options.

 For example , a cement retained ,
abutment supported crown on an
implant replacing mandibular right
first molar requires a minimum of
8mm of interarch space from the
osseous crest of edentulous space to
occlusal surface of opposing tooth . If
8mm is not available, then screw
retained implant crown would
necessary.

 For the edentulous patient , approx
17mm of interarch is required for
bar retained over dentureto occlusal
surace of opposing tooth.
 If it is lessthan 17mm, then
abutment retained overdenture is
necessary.

 crown to implant ratio need to be cosidered.
 If the interarch space between the osseous
crest of the edentulous site of the lower right
first molar and the opposing occlusal surface is
10 mm and the longest implant that can be
placed is 10mm. That is crown to implant ratio
is 1:1
 Any ratio lessthan 1:1 provides favorable
biomechanics. Eg: crown height 8mm supported
by implant of 13mm.
 There is potential biomechanical liability if ratio
exceeds greater than 1:1. eg: crown height of
15mm supported by implant of 8mm.

 Implant spacing must be understood.
 Implants need 1.5mm space from the
outer surface of implant to adjacent
root surface.
 And 3mm of space between two
adjacent implants.

 Concept of anteroposterior spread:
 Antero posterior spread is defined as distance
measured between a line drawn horizontally
through the distal of the most anterior implant
and a line drwn horizontally through the distal
of the most posterior implant on each side of
arch.

Surgical Treatment Planning Considerations:
 Anterior mandible is tall and wide
enough to accomodate implant
placement.
 Primary surgical concern in this area
include proper angulation of the
implants and avoiding the mental
foramen and mandibular canal.
 Implant should be placed 5mm
anterior to mental foramen avoiding
the anterior loop of mandibular canal.

 Posterior mandible limits the length of
the mandible based on the position of
mandibular canal that traverses the
body of mandible.
 Tip of the implant should be 2mm
above the IAN.
 Mylohoid muscle will maintain bone
along its attachment on the medial
aspect of mandibular body . A
significant depression is found just
below this. Lingual perforation may
occur if implant position and
angulation does not compensate.

 Posterior maxilla poses two specific concerns.
 First is the quality of the bone . It is limited by thin cortical bone
at the ridge crest and the least dense trabecular bone resulting in
less implant stability at the time of palcement.
 For this reason , morethan 6 months is required for
osseointegration to occur.
 Second is the proximity of maxillary sinus to edentulous ridge.
 As a result of bone resorption and increased pneumatization of
the sinus , a limited height of bone remains for implant
placement.
 Implant should be placed leaving 1mm of bone , if there is
inadequate height sinus lift procedure is to be carried.

 Anterior maxilla has thin buccal
cortical plate even in the presence of
healthy teeth.
 After tooth loss resorption follows
apically and palatally resulting in a
ridge that is narrow and angulated
such that ideal implant positioning is
difficult .
 Such cases need to be grafted prior to
implant placement.
 Implants should be placed 1mm short
of the nasal floor and should not be
placed in maxillary sinus.

 Final stage of treatment planning involves the consolidating all the clinical and radiographic
information in combination with surgical options and limitations to produce the best final
result of the prosthetic treatment.
 To facilitate implant placement , surgical guide templates are used as they are critical in
esthetic zone.
 Virtual treatment planning, 3D reconstruction using CBCT data can be used.
 Ultimate result should allow the surgeon to place the implant in bone optimally while
maintaining the angualtion that provides the best foundation for final restoration.
Final Treatment Planning:

 SURGICAL PREPARATION
 IMPLANT SITE EXPOSURE
 IMPLANT PLACEMENT : FLAP REFLECTION
 PREPARING THE OSTEOTOMY
 INSERTING THE IMPLANT
 SUTURING THE FLAP
 POST OPERATIVE MANAGEMENT
 UNCOVERING
Surgical Technique :

 Surgical procedure always start with detailed surgical preparation.
 Preopertive antibioticprophyxis is sometimes recommended.
 Once the patient has been draped in a sterile fashion and the surgical team has been
gloved and gowned , the patient is anesthetized.
 Implants can be placed using local anesthetic technique.
 More complex and lengthy procedures require sedation or general anesthesia.
 LA with vasocostrictors are used to achieve haemosatsis.
 It is imperative to have good access to operative site via effective retraction of cheeks and
the tongue. And a mouth prop is invaluable.
Surgical Preparation:

 Exposure of implant site can be accomplished with flapless surgery or with tissue elevation
that may include sulcular , midcrestal, and vertical releasing incisions.
 Flapless surgery may be indicated when there is adequate keratinized tissue over an ideal
ridge form.
 This creates least soft tissue trauma, and provides best esthetics in patients with excellent
presurgical anatomy and papilla shape.
 Implant and the healing restoration are placed in a single stage in flapless surgery.
Implant Site Exposure:

 When a flap is required , the incision should be designed to allow the unimpeded access for
implant placement.
 MIDCRESTAL INCISION
 VERTICAL RELEASING INCISION

IMPLANT PLACEMENT
 FLAP REFLECTION:
 Reflection at the papilla is initiated
with a periosteal or Molt elevator
cleanly releasing the subperiosteal
fibres, and the reflection is continued
by the elevation sulcularly to the distal
extent of the elevation.
 Once the buccal flap is reflected,
palatal or lingual flap can be retracted
enough to visualize the width of the
ridge.

 PREPARING THE OSTEOTOMY:
 Speed setting on the motar should be set at 1000 to
1500 rpm for the precision and pilot holes.
 Depth indicator markings should be reviewd on these
drills.

 Drilling is done with precision drill at
full speed to a depth of 2mm short of
intended implant. i.e, 8mm depth for a
10mm implant.
 Area is irrigated ,and 2mm pilot drill
positioned in the same location and
after verifying the angulation, drill is
run at full speed to the intended depth
of the implant. i.e, 10 mm depth for a
10mm implant.
A, Initial marking or preparation of the implant site with a
round bur. B, Use of a 2-mm twist drill to establish depth
and align the implant. C, Guide pin is placed in the
osteotomy site to confirm position and angulation. D, Pilot
drill is used to increase the diameter of the coronal aspect
of the osteotomy site.

 The area is rinsed and the guide pin that corresponds to the
intended final size of the planned implant is placed.
 Use of the guide pin allows the surgeon to evaluate the
position, spacing and angulation of developing osteotomy.
Also helps in evaluating where the pin lines up against
opposing dentition.
 The surgeon then determines the location on the twist drill
that corresponds to the intended platform position of the
implant to the ridge.
 The tip of the narrowest drill is placed into pilot hole and is
run at the full speed once position and angulation are
verified. And the site is sequentially prepared in this manner.
 The osteotomy is rinsed and the appropriate guide pin is
placed to reevaluate position and alignment.
. E, Final drill used is the 3-mm twist drill
to finish preparation of the osteotomy
site. F, Countersink drill is used to widen
the entrance of the recipient site and
allow for the subcrestal placement of the
implant collar and cover screw.

 The tip of the final twist drill is placed
in to the opening of the osteotomy
and run with great care as this is the
drill that finalizes the osteotomy.
 The osteotomy is then inspected with
thin instrument for possible bony
perforation.
 After completing the osteotomy,
speed of motor is changed to 30
newton cm.
 Osteotomy could be easily damaged if
speed is not changed.

 INSERTING IMPLANT:
 Implant is opened and placed on the driver that
has been inserted in to the handpiece.
 Handpiece must be held such that the tip of the
implant is ponting up.
 The implant is driven into the postion by keeping
light pressure in apical direction.
 Using the hand torque wrench, surgeon continues
to seat the implant,using the torque lever of the
wrench to quantify the amount of torque present.
 Seating of the implant is finalized by verifying that
the platform is even with the mesial and distal
heights of bone .

 The area is irrigated thoroughly and and it should be
detrmined if there will be single stage or two stage healing
period.
 This is determined by the torque value measured on surgical
motor.
 An implant with a torque value of 35 Ncm or greater is
considered to have good primary stability and single stage
healing is possible and a healing abutment is placed.
 If two stage healing is required, then an appropriate sized
cover screw is placed.
 Abutment should protrude 2mm through the tissue.
 A tapered abutment rather than a parallel abutment must be
determined.

 Intended tissue emergence of planned
restoration determines whether
healing abutment is tapered or
parallel.
 Healing abutment is placed on to the
insertion wrench and screwed in to
the implant and tightened with finger
pressure making sure no tissue is
caught under the abutment.
 And finally the flap is sutured using
chromic gut or vicryl.

Post operative management
 A radiograph should be taken
postoperatively to evaluate the position
of the implant in relation to adjacent
structures such as sinus , inferior
alveolar canal .
 Mild to moderate strength analgesics
are usually sufficient.
 Antibiotics are given prophylactically but
are usually not required postoperatiely.
 Patients are instructed to use 0.12%
chlorhexidine gluconate rinses for 2
weeks after surgery.
 Patient is evaluated weekly until soft
tissue healing is complete.

Uncovering
 In single stage surgery, no surgical uncovering is
necessary.
 The implant stays exposed via the healing
abutment after surgery and throughout the
healing phase.
 In a two stage system, implant must be
surgically uncovered and a healing abutment
placed.
 Goals of surgical uncovering are to attach the
healing abutment to the implant , preserve
keratinised tissue and modify the form or
thickness of tissue.
 and final prosthesis is placed.

 Primary goal in implant placement is to achieve and maintain an intimate bone to implant
connection.
 This concept is known as OSSEOINTEGRATION.
 HISTOLOGICALLY defined , osseointegration is the direct structural and functional connection
between organized , living bone and the surface of a load bearing implant without intervening
soft tissue between the implant and the bone.
 CLINICALLY ,is defined as the asymptomatic rigid fixation of an alloplastic material in bone
with the ability to withstand occlusal surface.
 This concept of osseointegration was brought by PER INGVAR BRANEMARK.
Peri-implantation biologic and functional considerations:
HARD TISSUE INERFACE

This Concept Of Osseointegration Was Brought By PER INGVAR BRANEMARK.

 A BIOCOMPATIBLE MATERIAL (THE IMPLANT)
 ATRAUMATIC SURGERY TO MINIMIZE TISSUE DAMAGE
 IMPLANT PLACEMENT IN INTIMATE CONTACT WITH BONE
 IMMOBILITY OF IMPLANT ,RELATIVE TO THE BONE , DURING THE HEALING PHASE
For Osseointegration To Occur, Factors Required Are:

(B) Atraumatic Surgical Technique:
 Atraumatic surgical technique, in an aseptic
environment , is critical to minimize
mechanical and thermal injuries to bone.
 This involve s using sharp, precision
osteotomy drills run at slow speed with high
torque , maintaining gentle ,intermittent
pressure while providing copius irrigation.
 Irrigation can be accomplished either
externally or internally using special
handpieces and burs with internal ports.
 The goal is to maintain BONE TEMPERATURE
BELOW 47 DEGREE CELSIUS.
 Temperature exceeding morethan this causes
bone necrosis and failure of osseointegration.

(C) Intimate Contact With Bone:
 For the implant to have intimate
contact with bone, implant site must
be prepared with a precise technique.
 All implant systems have specially
designed drills that are used in a
specific sequence to remove bone as
atraumatically as possible .
 The drill sizes are matched to the size
and shape of the implant being placed
, creating the precision necessary for
developing initial bony contact.

 Stability at the time of placement is predicted on the volume and quality of bone that
intimately contacts the implant as well as the length and diameter of the implant.
 The best case scenario would be long wide diameter implant that engages a thick , superior
cortical plate surrounded by dense cancellous bone and terminately engages a thick inferior
cortical plate.
 During the time required for osseointegration to occur, it is imperative that immobility of the
implant be maintained. Therfore in areas where implant primary stability may be less, a
SUBMERGED NON LOADED HEALING PERIOD followed by surgical UNCOVERING OF IMPLANT
would be required.
(D) Implant Immobility:

SOFT TISSUE INTERFACE:
 Soft tissue has become a major focus of interest primarily
by the need for esthetics and as a barrier against bacterial
invasion.
 Peri implant and periodontal soft tissues do share a
number of similarities and only subtle differences.
 From JE to down to level of alveolar bone , both types of
soft tissues possess a zone of dense connective tissue. This
zone of SUPRACRESTAL CONNECTIVE TISSUE is resposible
for maintaining a stable interface between soft tissue an d
the implant and act as a barrier to the oral environment.
 Here the orientation of fibres run parallel to the implant
surface with NO INSERTING SHARPEY ‘S FIBRES .
 Probing depth in healthy implant is 1 to 2mm.
 Implant however is in direct with bone, without any
intervening soft tissue. This difference has dramatic impact
on biomechanics, proprioception,prosthetic consideration
of implant versus natural teeth.

Biomechanical Considerations:
 Once the implant is properly placed, the longterm success
depends on restorative biomechanical factors that is how the
stresses imposed on functioning implant will be controlled or
distributed so as to maintain a healthy biologic connection
between bone and the implant.
 The LOAD BEARING capacity of the integrated implant has to be
GREATER THAN the anticipated LOAD DURING FUNCTION.
 If applied loads are greater than load bearing capacity, it results in
MECHANICAL FAILURE, BIOLOGIC FAILURE OR BOTH.
 Mechanical failure may present as porcelain fracture or loosening
of screw that attaches abutment to implant.

 Biological failure occurs when the functional loads exceeds
load bearing capacity of IMPLANT BONE SURFACE.
 This initially presents clinically as boneloss around the
platform of implant.
 If the provocation is long enough, bone loss may progress
around the entire implant resulting in complete failure.
 The clinician must remember that implant retained
restoration lacks shock absorbing pdl which allows the
natural tooth to move and adapt to the forces without
pathologic bone loss.

Factors qualifieing the load bearing capacity:
 Number and size of implants:
 number of implants placed in multitooth
edentulous spans affects load bearing capacity.
 If there is three tooth edentulous span, the
fixed prosthetic options would be to place 3
implants with 3 splinted crowns, 3 implants
with 3 single unit crowns, 2 implants as
terminal abutments for a 3 unit or 2 adjacent
implants with a FPD with a cantilever pontic.
 Load bearing capacity decreases with each
successive option.

 Arrangement and angulation of implants:
 Straight or linear arrangement of multiple implants
should be avoided as this provides least biomechanical
advantage and is the least resistant to torquing forces
caused by offcentre occlusal and lateral loads.
 Implants should be placed in more curvilinear or
staggered fashion.
 Connecting a single integrated implant to one natural
tooth with FPD will effectively create an exceessively
loaded cantilever situation. Reason being the biting
forces on the natural tooth and pontic cause stress to
be concentrated at superior portion of the implant.

 Connecting a single integrated implant to one
natural tooth with FPD will effectively create an
exceessively loaded cantilever situation.
Reason being the biting forces on the natural
tooth and pontic cause stress to be
concentrated at superior portion of the
implant.

 Angulation of the implants as it relates
to the occlusal plane and the direction
of the occlusal force is important in
optimizing the translation of the
forces to the implants and
surrounding bone.
 Loads directed through the long axis
of the implants are tolerated well.
 Off-axis loading can result in
unfavourable forces on the the
implant jeopardizing longterm success
because of excessive lateral loads.

 Volume and quality of bone implant surface:
 Thick cortical bone and dense trabecular bone surrounding a long wide diameter
implant that is positioned to be in line with functional load would offer greatest load
bearing capacity.
 A short narrow diameter implant placed in an area of thin cortical bone and less
dense trabecular bone in an off axis angulation would have far less load bearing
capacity.

Maxillary sinus grafting:
 The loss of posterior teeth and subsequent
maxillary sinus pneumatization results in atrophy
of the alveolar bone and can affect the proper
rehabilitation of patients with osseointegrated
implants.
 The use of this procedure in order to insert
implants was introduced by Tatum and published
as a clinical study by Boyne and James.
 This procedure is suitable for the rehabilitation of
both a posterior tooth and a completely
edentulous maxilla in regions with loss of alveolar
bone and sinus pneumatization.

 Tatum, Boyne & James first performed sinus augmentation in the mid 1970’s with autogenous
bone placed into the sinus.
 Misch (1987) reported 98% success with 170 sinuses grafted with tricalcium phosphate
combined with demineralised bone & blood.
 Smiles & Holmes (1987) used porous hydroxyapatite particles as sinus graft materials.
Kent & Block (1989) reported using autogenous iliac crest graft.
Since then ramus, coronoid process, tuberosity, chin, calvarium, tibia and rib have been
used.

 Traditionally, the success of the maxillary sinus lift procedure is determined by the amount
of vital bone formation after maturation of the graft and the long-term survival rate of the
implants placed in that region.
 Two approaches are commonly used: the lateral window technique and the osteotome
intrusion technique.
 The latter is indicated when at least 5–6 mm of alveolar bone is present, showing a gain of
4–8 mm in bone height, and there is sufficient bone to stabilize the implant.
 The lateral window technique is indicated when large bone gains are required in severely
resorbed jaws; implants can be installed immediately if primary stability is obtained, or after
bone healing.8

91
SINUS LIFT
There are two main
approaches to lift
the maxillary sinus
Direct( Caldwell
luc)
Indirect

 Various grafting materials have been used in
maxillary sinus lift surgery, including autologous
bone, xenogeneic bone, demineralized or
mineralized allogeneic bone, and alloplasts.
 According to Chen et al., bone formation in the
maxillary sinus does not require the presence of
biomaterial.
 The maintenance of space for blood clot
formation accompanied by the resorption and
deposition of bone cells derived from the sinus
periosteum or cancellous bone of the maxilla
would be responsible for bone formation in this
region.

Direct or lateral window technique:
 The procedure is performed from inside the patient’s
mouth where the surgeon makes an incision into the gum,
or gingiva.
 Once the incision is made, the surgeon then pulls back the
gum tissue, exposing the lateral boney wall of the sinus.
The surgeon then cuts a "window" to the sinus, which is
exposing the Schneiderian membrane.
 The membrane is separated from the bone, and bone graft
material is placed into the newly created space. The gums
are then sutured close and the graft is left to heal for 4–12
months.[7]
 The graft material used can be either an autograft, an
allograft, a xenograft, an alloplast (a growth-factor infused
collagen matrix), synthetic variants, or combinations
thereof.[

 As an alternative, sinus augmentation can be performed by a
less invasive osteotome technique.
 This technique is normally performed when the sinus floor
needs to be lifted less than 4 mm. The osteotome technique is
performed by flapping back gum tissue and making a socket in
the bone within 1–2 mm short of the sinus membrane.
 The floor of the sinus is then lifted by tapping the sinus floor
with the use of osteotomes. The amount of augmentation
achieved with the osteotome technique is usually less than
what can be achieved with the lateral window technique.
 A dental implant is normally placed in the socket formed at the
time of the sinus lift procedure and left to integrate with bone.
Bone integration normally lasts 4 to 8 months.
 The goal of this procedure is to stimulate bone growth and form
a thicker sinus floor, in order to support dental implants for
teeth replacement.
94
INDIRECT TECHNIQUE
Invented by SUMMER IN 1994

Sinus lift procedure
 Surgical photograph showing an
incision at the crest of the ridge,
followed by a full-thickness,
mucoperiosteal reflection to expose
the lateral wall of the maxilla. A round
bur has been used to remove the
cortical bone, exposing the underlying
sinus membrane.


 Small Woodson elevator is used to
elevate the thin sinus membrane from
the inner aspect of the maxillary sinus.


 Sinus membrane is raised, and the lateral wall of the
maxilla is then rotated medially into the sinus.
 The membrane is elevated with a small perforation.
 Small perforations (such as the one shown) can be
left alone with no treatment.
 If a large perforation is made, the procedure may be
aborted, unless a solid block of bone is used rather
than particulate bone.
 When the membrane is elevated and positioned in
the superomedial aspect of the sinus, it often folds
on itself; this folding closes over any perforations.

 Membrane has been elevated, and
the tibia bone has been placed.

 The graft is placed into the medial
aspect of the sinus, followed by the
implants and additional graft material.
Additional material then is placed to
augment the thin alveolar ridge.

 After 6 months, the implants are
exposed through a crestal incision. The
implants are covered with bone.

 The first case of inferior alveolar nerve repositioning was reported by Alling in 1977
to rehabilitate patients with severe atrophy for dentures [9]. Jenson and Nock in
1987 car‐ ried out IAN transposition for placement of dental implants in posterior
mandibular re‐ gions [10]. In 1992, Rosenquist performed the first case series study
on 10 patients using 26 implants. He reported an implant survival rate of 96% for
this procedure [11] and therefore, this technique was accepted as a treatment
modality for reconstruction of the dentoalveolar system with dental implants in the
posterior mandible.
LATERALIZATION OF INFERIOR ALVEOLAR NERVE:

 Inferior alveolar nerve transpositioning for implant placement is usually performed
by 2 techniques: IAN transpositioning without mental nerve transpositioning or
involvement of mental foramen: This is usually employed when the edentulous area
and alveolar ridge resorption does not include the premolars. This technique has
been called nerve lateraliza‐ tion .
 IAN transpositioning with mental nerve transposi‐ tioning or involvement of mental
foramen: In cases where the edentulous area and ridge resorption include the
premolar teeth, there is a need for transpositioning of mental neuro‐ vascular
bundle and even transection of incisal nerve and transposing the nerve distally (as‐
sociated with mental nerve and mental foramen involvement). This method has also
been called nerve distalization .

 Correct flap design: an incision is
made on the alveolar crest with a
releasing incision at the mesial of the
mandibular canine

 : Method of removing bone block without the involvement of
mental foramen: In this technique, a bur is used to outline the
location of bone block on mandibular buccal cortex by a dis‐
tance from the inferior border of mandible and alveolar crest.
The mesial incision should be made in 3-4 mm away from the
mental foramen. Then the buccal bone surrounding the canal
is removed carefully by reciprocal motion us‐ ing an
osteotome (Chisel)..
 B: Removal of bone block along with mental foramen
involvement: Similar to the previous method, a bur is used to
outline the bone block area. An osteotome (chisel) is used to
remove the bone block and the spongy bone is re‐ moved
using a curette. In this technique, the preparation design
includes the surroundings of the mental foramen.

 Cavity preparation and bone drilling
when the nerve is retracted from the
site using a umbilical tape 10 mm wide
or elastic band in order to protect it
from any damage during drilling or
implant placement.

 Dental implants placement after the
lateralization of the IAN.

 Repositioning and stabilizing the
buccal bone plate with surgical steel
wire 2.0.

Pterygoid and zygoma implants:
 The use of pterygoid implants was described by
Tulasne and subsequently used by many other
researchers.
 They are anchored in the pterygoid; however, in
some studies they are placed in a more anterior
position, in the pterigomaxillary area and
parallel to the posterior wall of the sinus.
 These implants have advantages over other
techniques: They allow anchorage in the
posterior atrophied/resorbed maxilla without
sinus lifts or bone grafts, achieving stability and
high rates of long-term success.

 The zygomatic fixture is an extended length (35 to 55
mm) titanium implant placed into zygomatic and
maxillary alveolar bone.
 It was designed for situations where atrophy of the
posterior maxilla complicates or prevents the placing of
conventional implants (1-3).
 The original technique was first described by Branemark
(4), who in 1998 published a follow-up over 10 years of
164 implants anchored in zygomatic bone, with a success
rate of 97%.
 The use of zygomatic implants avoids the need for bone
grafting, shortens treatment and reduces morbidity

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