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Fourth year Class 2011/2012 IMPLANT–SUPPORTED FIXED PROSTHESIS

BY Dr MoHAMeD H. GHAZY Febuary 12, 2012

• Implant prosthodontics :

• The phase of prosthodontics concerning replacement of missing teeth and/or associated structures by restorations that are attached to dental implants

A prosthetic device of alloplastic material implanted into the oral tissue beneath the mucosal or/and periosteal tissue for fixed or removable prosthesis

What is a dental implant ?

Indication & contraindication

Indications • Single tooth loss

• Inability to wear a removable P.D.

• Free end distal extension • Need for long span FPD with

questionable prognosis • Unfavorable number and location

of potential natural tooth abutment

Contraindications • Lack of operator experience

• Smoking

• Pregnancy

• Immunosuppression (chemotherapy, HIV, etc)

• Antimetabolic treatment

• Poorly controlled cardiovascular problems

• Tumoricidal radiation to implant site

• Psychiatric disorders

• Patients with bone diseases, such as Histiocytosis X, Paget's Disease and Fibrous Dysplasia

• uncontrolled hematologic disorders such as Generalized Anemias, Hemophilia

• Patients with endocrine disorders, such as uncontrolled Diabetes Mellitus, Pituitary and Adrenal insufficiency and Hypothyroidism

Treatment planning for implant patient Indication &contraindication

Clinical evaluation Adequate bone and anatomic structure

Visual inspection & palpation Flabby excess tissues

Bony ridges

Sharp underlining osseous formations and undercuts

Radiographic evaluation Panoramic view with small radio opaque reference

Cephalometric film to evaluate bone width

CT scan to locate inferior alveolar canal & maxillary sinuses

Diagnostic casts Study the remaining dentition

Evaluate residual bone Analyze maxillo-mandibular relationship

Diagnostic waxing and surgical templates

Bone sounding With probe judging the soft tissue thickness and bone soundness

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Subperiosteal Transosteal

Endosteal plate

form

Endosteal

root form

To the left you can

see a typical modern

Root form Implant

and to the right of

the implant is a

picture of a natural

tooth.

One can see how the

implant is designed

to replace the root of

a tooth by the

somewhat apparent

similarity.

Screw Retained

Transocclusal

Screw Retained

Transversal

Cemented

Fixed Partial Denture

Implant supported prosthesis may be

OSSEOINTEGRATION A direct structural and functional

connection between ordered living

bone and the surface of a load

carrying implant

Swedish professor of orthopedics

named Per-Ingvar Branemark in 1965 he used the first titanium dental implant into a human volunteer

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Implant most commonly used from

–commercially pure (CP) titanium – titanium-aluminum-vanadium alloy (Ti-

6Al-4V) - stronger & used w/ smaller diameter implants

Why Titanium

• lightweight • biocompatible • corrosion resistant (dynamic inert oxide layer)

• strong & low-priced

Principles of Implant location Anatomic limitation

General guide lines

• Ideal bone should be 10 mm vertical and 6 mm horizontal

• Two mm above the superior aspect of inferior alveolar canal

• Five mm anterior to mental foramen

• one mm from the periodontal ligament of adjacent tooth

• Three mm between 2 implant to ensure bone vitality.

Anterior maxilla

• 1- Minimum of 1 mm between the

implant apex and nasal vestibule

• 2- Implant slightly off midline on either

sides of incisive foramen.

Principles of Implant location Anatomic limitation

Posterior maxilla

Bone less dense, larger narrow spaces, and thin cortex

• 1- One implant for every tooth

• 2- One mm of bone between the floor of

sinus and implant

Principles of Implant location Anatomic limitation

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Anterior mandible

• 1- One implant placed through the

entire cancellous bone

• 2- Five mm anterior to the foramen

Principles of Implant location Anatomic limitation

Posterior mandible

• 1- Two mm above the superior aspect

of inferior canal

• 2- More time required for integration

• 3- Attachment of mylohyoid muscle

Principles of Implant location Anatomic limitation

Principles of Implant location Restorative consideration

Implant placement 1- Stay 1mm from the adjacent natural tooth but not so far

to for contouring restoration

Less ideal location

2- Long axis of implant should be positioned in the central

fosse of the restoration

Principles of Implant location Restorative consideration

Implant placement

Natural

tooth

Ideal

implant placement

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Implant and restoration size 1-Size should be considered during treatment planning

2- 4mm diameter for maxillary central

3- 3mm for mandibular incisors

4- 5-6mm for molars

Surgical guide Template extremely useful for anterior

implant Objectives 1- Delineate the embrasures 2- Locate the implant within the restoration contour 3- Align the implant within the long axis of the restoration 4- Identify the level of CIJ or tooth emergence from the soft tissue

Wax model of a tooth to be replaced in the surgical guide

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Surgical guide template

Stent used as guide for implant placement

Surgical guide for correct implant

placement Implant surgery

Surgical access

Implant placement

Postoperative evaluation

Implant uncover

Guide drill / 2mm twist drill / Pilot drill / 3mm twist drill / Countersink

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Implant restorations Significant factors for success 1- Precise placement 2- A traumatic surgery 3- Unloaded healing 4- Passive restoration

Fourth year Class 2011/2012 IMPLANT–SUPPORTED FIXED PROSTHESIS

BY Dr MoHAMeD H. GHAZY February 19, 2011

Implant fixture

Abutment

Retaining screw

Abutment screw

Components of an

implant restoration Composite resin

Screw- retained implant

restorations consist of

three components.

(a) Implant fixture

(b) Abutment

(c) Restoration

- The abutment screw secures

the abutment to the fixture

- The prosthetic retention screw

secures the prosthesis to the

abutment.

Gutta percha

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• Lekholm and Zarb bone type classification Type I bone homogenous, compact bone Type II bone a thick layer of compact bone surrounding a core of dense trabecular bone Type III bone a thin layer of cortical bone surrounding a core of dense trabecular bone of good strength Type IV bone thin layer of cortical bone surrounding core of low density .

Implant insertion into

the prepared socket

Unscrewing the abutment from the implant

fixture, screw covering and suturing

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Removal of the cover screw in

the 2nd stage and abutment attached to the fixture as a

coping ready for impression

The abutment removed from the implant

fixture

Abutment and its implant analog and

repositioned in the impression

Abutment prepared to its final form in the

working cast

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Prepared abutment and final restoration

in the patient mouth Impression post Closed tray

Impression

Imp post & analog

Imp post & analog relocated on the

impression

Polyether soft tissue injected around

analog before

pouring

Implant restorations

Poured cast

Impression coping locates the analog in

the same position in

the cast as the implant in the mouth

Contouring of the soft tissue material

Zirconia abutment seated on cast Zirconia abutment

seated in the mouth

Zirconia abutment for cement retained

restoration selected

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Dental Implant Should promote bone in-

growth. Structure and

geometry differences are the selling point for most

companies.

Prosthetic Crown Look and feel of real

tooth. Easily replaced.

Abutment Secures the crown to the

Dental Implant. Can be

straight or angled depending on implant location

Titanium

screw

Clinical Implant system components

Hydroxyl appetite coated screw

Hydroxyl Apatite coated cylinder

Titanium plasma sprayed cylinder

Implant body

Titanium screw

Is the component placed within the bone during 1st stage surgery

Two images showing two different types of tapered,

cylindrical implants. One looks like a Christmas tree with fins projecting out to the sides; the other shows a special surface

treatment consisting of spherical titanium beads.

Cover screw It is the component placed over the dental implant during the

osseointegration phase to seal the occlusal surface of the

implant and prevent tissue from proliferating into the internal

portion of the implant body It should be of low profile to facilitate the suturing of soft

tissue tension _free.

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Healing abutment

A- screw into implant

B- Screw into abutment

(healing cap)

Dome shaped 2-10 mm screw placed on the implant after the 2 and stage surgery & before insertion of the prosthesis

Healing Abutments

Transgingival Titanium piece which

will form the soft tissue

Selected considering the

Emergence Profile needed for the restoration and the tissue height

Healing Abutments

Necessary Information:

Healing Abutment Height

Platform Diameter (normally same as implant diameter )

Healing Abutment Diameter (EP Profile

Height

Restorative Platform

EP® (Emergence Profile)

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Abutment Component of the implant system that screw directly into the implant to support and or retains a prosthesis or implant superstructure

Abutment

Abutment

screw

(green)

Abutment

- can be either parallel

(standard) or conical

(estheticone) in shape.

- are secured with an

abutment screw that is

tightened to 20 Ncm.

(Screw retained restoration)

Abutment

(Cemented restoration)

- Cera One abutment

- secured with a square

head screw tightened to 32

Ncm.

(red)

Straight

15º Pre-Angled

Engages Implant Hex

Engages 12 Point Double Hex

Click Zone

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2 impression techniques

Open tray impression Closed tray impression

Education

Open tray impression Concept

Intraoral situation Implant & impression post Analog & impression post

55 Education

Impression procedure

Remove closure screw or healing abutment

Insert impression post and hand tighten screw with the screwdriver

56 Education

Take impression with an open tray

Use an elastomeric impression material

Impression procedure

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57 Education

When impression material is set, unscrew and remove the impression

Impression procedure

A one piece coping

Screw into the abutment

used if the abutment does not need to be changed on the

lab cast

Two piece coping

Screw into the implant

used if the abutment does not need to be

changed on the lab cast

Two piece coping

Screw into the abutment

used to orient the anti-rotational feature or to

make impression of very divergent implant

Types of impression posts

Two piece Impression coping

Impression coping attached to the implant analog

• The impression posts attached to the implants fixtures.

Impression with laboratory analog to make the master cast.

The master cast is that one used to fabricate the final prosthesis.

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Laboratory analogs Components made to represent the top of the implant fixture or the abutment in the laboratory cast

Fixture analog

{Duplicate implant top}

Abutment analog

{Duplicate abtument top}

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Attach Analog

Push Analog/Impression Coping Assembly into Impression Twist and Lock Grooves into Impression

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Waxing sleeves

Plastic waxing sleeve tightened

to a laboratory analog

Gold cylinder tightened to a

laboratory analog

Combination

Prosthesis retaining

screw Screw used to secure the

prosthesis to the implant

or the transmucosal

abutment

Prosthetic

retaining screw

Prosthetic retaining screw

Have a slot or hex head Access is usually covered by a combination of gutta percha and composite. used to retain the prosthesis to the abutment. Tightened to 10 Ncm.

Implant fixture

Abutment

Retaining screw

Abutment screw

Components of an implant

restoration Composite resin

Screw retained implant restorations

consist of three components.

(a) Implant fixture

(b) Abutment

(c) Restoration

- The abutment retaining screw

secures the abutment to the fixture

- The prosthetic retaining screw

secures the prosthesis to the abutment.

Gutta percha

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Screw retained implant crown Slot Screw

Driver

- Used to remove or replace slotted prosthetic retention screws.

- Tighten to 10 Ncm

Hex Screw Driver

- Used to remove or replace hex prosthetic retention screws.

- Tighten to 10 Ncm.

Abutment Screw Driver

- Used to remove or replace abutment screws for standard or

conical (estheticone / mirus cone) abutments.

- Tighten to 20 Ncm.

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Square Screw Driver

- Used to remove or replace Cera One abutment screw.

- Tighten to 32 Ncm

Impression tray without impression material: After the impression tray is prepared, it should be checked to see that it fits and fully covers the area of the impression and that the hole in the tray is aligned with the guide pin.

Impression tray with impression material in the jaw: The coping must be completely covered by impression material and the tray be fully seated. It is very important that the guide pin protrudes through the impression tray in order to open it with the hex driver.

Inverted impression tray with emphasized hex: The hexagon of the impression coping can be seen. It is very important to check that the position of the impression coping has been accurately recorded and that the hex is clear of any impression material.

Inverted impression showing gingiva being syringed around analog The analogue can now be attached to the impression coping by screwing in the guide pin. It should be confirmed that the coping is attached to the analogue with no misalignment of gaps. At this stage, injecting impression material around the neck of the analog can simulate the gingiva.

Stone model prepared with simulated gingiva and implant analog In the final stage in impression taking, a stone model of the gingiva and teeth should be cast, and the simulated gingiva should remain on the model. After the stone is hardened, the impression coping can be released from the model by removing the guide pin. The impression tray can now be separated from the model

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Silicone index and wax model of tooth When the wax model of the tooth is appropriately positioned a silicon key can be prepared that will serve as a good replica of the missing tooth.

Option 1: Placing the gold plastic cylinder abutment on the stone model Following the construction of the silicone index a gold plastic cylinder abutment with hexagon can be selected.

Option 1: Wax Carving The plastic part of the gold plastic cylinder abutment can now be grind to the appropriate height on the stone model, taking into account the height of the adjacent teeth. After the gold abutment and the plastic cylinder have been prepared, it is possible to carve the wax to the desired shape. Following the carving of the wax on the gold abutment and the plastic cylinder they will be cast.

Option 1: Silicon index with wax up The silicon index will be used to check that the dimensions of the wax-up are appropriate to its surroundings.

Option 1: Metal casting When fabricating P.F.M crown, using the direct wax-up technique on the cap to get a metal frame onto which the porcelain firing takes place. Checking the metal on the stone model and the seating of the external hex of the gold abutmnent in the internal hex of the implant analog.

Option 1: Porcelain in mouth After placing the crown, the screw of the gold abutment should be tightened to 20 Ncm utilizing the TORKIT wrench. This will minimize the chances of the screw opening. After the screw has been tightened, the screw hole should be closed.

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Option 2: Placing the plastic cylinder on the stone model Following the construction of the silicon index a plastic cylinder with hexagon can be selected

Option 2: Wax Carving The plastic cylinder can now be grind to the appropriate height on the stone model, taking in the account the height of the adjacent teeth. After the plastic cylinder have been prepared, it is possible to carve the wax to the desired shape. Following the carving of the wax on the plastic cylinder they will be cast.

Option 2: Silicon index with wax up The silicon index will be used to check that the dimensions of the wax-up are appropriate to its surroundings. MT-HHR13

Option 2: Metal casting When fabricating P.F.M crown, using the direct wax-up technique on the plastic cylinder a metal frame onto which the porcelain firing takes place. Checking the metal on the stone model and the seating of the external hex of the casting (what was previously the external hex. of the plastic cylinder MD-CPH13), in the internal hex of the implant analog.

Option 2: Check the casting in the mouth After completion of the casting, a check must be made in the paient’s mouth using the screw MD-SO220 to connect it.

Option 2: Porcelain on plaster model Following the selection of the appropriate color, the porcelain is fired on the metal casting.

Option 2: Porcelain in mouth After placing the crown, the screw of the plastic cylinder should be tightened to 20 Ncm utilizing the TORKIT wrench. This will minimize the chances of the screw opening. After the screw has been tightened the screw hole should be closed.

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IMPLANT RESTORATIVE OPTIONS Distal-extension Implant Restoration. There are two distal-extension restorative options.

1. Tooth-implant supported restoration Place an implant distal to the most

posterior natural abutment and fabricate a fixed prosthesis connecting the implant with the natural tooth. However, there are problems associated with implants connected to natural teeth .

2. Implant supported restoration Place two or more implants posterior to the most distal natural tooth and fabricate a completely implant-supported restoration ).

If the crown-to-implant ratio is favorable, two implants to support a three-unit fixed prosthesis. If implants are short and crowns are long, one implant to replace each missing tooth. If doubt remains, more implants are used when heavier forces are expected (e.g., posterior part of the mouth in patients with evidence of parafunctional activity). Fewer implants are used when lighter forces are expected (e.g., those opposing a complete denture or those supporting a prosthesis in the anterior part of the mouth).

IMPLANT RESTORATIVE OPTIONS Distal-extension Implant Restoration.

Long Edentulous Span Restoration. 1. The clinician may choose to have multiple

implants placed between the remaining natural teeth and to fabricate a fully implant-supported restoration.

2. One or two implants can be placed in the long edentulous span and the final restoration connected to natural teeth.

When it is necessary to connect implants and the natural teeth, protecting the teeth with telescopic copings is recommended .

In this manner, prosthesis retrievability can be maintained.

Some long edentulous spans require the reconstruction of soft and hard tissue and teeth. using resin teeth processed to a metal substructure rather than a conventional metal-ceramic restoration is recommended.

Soft tissue esthetics can be more easily and accurately mimicked with heat-processed resin and large defects .

This type of restoration has been called a hybrid because it combines the principles of conventional fixed and removable prosthodontics.

IMPLANT RESTORATIVE OPTIONS Distal-extension Implant Restoration. Long Edentulous Span Restoration.

Single-tooth Implant Restoration. Indicated in the following situations:

1. An otherwise intact dentition 2. spaces difficult to treat with conventional fixed prosthodontics 3. Distally missing teeth. 4. A prosthesis that needs to closely mimic the missing natural tooth

The requirements for single-tooth implant crowns are:

1. Esthetics 2. Ant rotation to avoid prosthetic component loosening 3. Simplicity-to minimize the amount of components used 4. Accessibility-to maintain optimum oral health 5. Variability-to allow the clinician to control the height, diameter, and angulations of the implant restoration

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IMPLANT RESTORATIVE OPTIONS Distal-extension Implant Restoration.

Long Edentulous Span Restoration. Single-tooth Implant Restoration.

Fixed Restoration in the Completely Edentulous Arch. 1.The hybrid prosthesis is a cast alloy framework with processed denture resin and teeth. It requires a minimum of five implants in the mandible and six in the maxilla. Suitable for patients who have had moderate bone loss, the prosthesis restores both bone and soft tissue contours. 2. The metal-ceramic rehabilitation also requires five implants in the mandible and six in the maxilla. Only if minimal bone loss has occurred and is best suited for patients who have recently lost their natural teeth (within 5 years). 3. For patients with severe bone loss, there is probably only one option: a removable restoration . Minimal resorption

—Metal ceramic restorations

Moderate resorption —resin to metal restorations

sever resorption —Over denture

CEMENT-RETAINED VERSUS SCREW-RETAINED IMPLANT CROWNS Zinc phosphate, glass ionomer, and composite resin cements have all been suggested for this purpose. Advantages of cement-retained restorations. 1. Simplicity 2. Less expensive. 3. Allow minor angle correction. 4. More esthetically pleasant

Disadvantages of cement-retained restorations. 1. Require more chair time 2. Have the same propensity to loosen as the

screw retained. Advantages of screw-retained restorations. 1. Retrievability

Disadvantage of a screw-retained implant

restoration 1. The screw may loosen during function. 2. Cost

CEMENT-RETAINED VERSUS SCREW-RETAINED IMPLANT CROWNS If the screw is sufficiently tightened into the implant crown to seat it, a clamping load or preload is developed between the implant and the crown. If this clamping force is greater than the forces trying to separate the joint between implant and crown, the screw will not loosen.

Screw Retained

Transocclusal

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Screw-Retained Crowns

Screw Retained

Transversal

Cemented Crowns