mandibular overdenture (2).pdf

7/21/2019 mandibular overdenture (2).pdf

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Implant assisted

mandibular overdenture



mandibular overdenture



Adv. Of mandibular over denture

versus conventional complete

denture



Improved

esthetics

speech

prosthesis

support

prosthesis

retention

occlusal

efficiency

chewing

efficiency

occlusion

stability



n a stu y y wa et a ., implant overdenture (IOD)

patients were able to chew

different types of foodsignificantly better than patients

with complete dentures (CDs).

(Data from Awad MA, Lund JP,

Dufresne E, et al: Comparing theefficacy of mandibular implant-

retained overdentures and

conventional dentures among

middle-aged edentulous patients: satisfaction and

functional assessment,



Adv. Of over denture versus the

fixed restoration Fixed Prosthesis



bonegrafting

specific implant placement

Fewer implants(RP-5)

Lower cost andlaboratory cost(RP-5)

Reduced stress

Hygiene

Improved

periimplant probing Improvedesthetics

Easyrepair

Stress

relief

attachment



Philosophy for Implants

in the

Edentulous Mandible



• In the case of multiple

extractions, this often means a

4-mm vertical bone loss within

the first 6 months.

• This bone loss continues over

the next 25 years, with the

mandible experiencing afourfold greater vertical bone

loss than the maxilla.

• As the bony ridge resorbs in

height, the muscle

attachments become level with

the edentulous ridge which

affect the retantion, stabilityand su ort of the denture.



• To the contrary, the anterior bone

under an overdenture may resorb as

little as 0.6 mm vertically over 5

years, and long-term resorption

may remain at less than 0.05 mm

per year.

• the dental professional should

educate the patient about the

bone loss process after tooth loss.

In addition, the patient should be

made aware the bone loss process can

be arrested by a dental implant.

• dental implants to maintain



Classification of

Prosthesis Movement

PM)



• An overdenture is by definition removable, but

in function or parafunction, the prosthesis may

not move.

• If the prosthesis does not have movement

during function, it is designated PM-0 and

requires implant support similar to a fixed prosthesis.

• A prosthesis with a hinge motion is PM-2, and

a prosthesis with an apical and hinge motion isPM-3.

• A PM-4 allows movement in four directions,

and a PM-6 has ranges of PM in all directions.



Implant site

selection





• Anatomical reasons:

more bone anterior increase thelength and width of the

implant…..increase the implantstability.



• Biomechanical consideration:

Overdentures with posterior

movement gain better acceptance

than removable restorations withanterior movement. The anterior

denture teeth are most often slightly

anterior to the edentulous ridge. As

a result, although the prosthesis is

more stable with anterior implants,

horizontal or vertical forces to the

mandibular anterior teeth cause the prosthesis to rock down in the front

(and up in the back



The available bone in the anterior mandible

(between the mental foramina) is divided

intofive equal columns

of bone serving as potential implant sites, labeled A, B, C, D,

and E, starting from the patient’s right .

Regardless of the treatment option being

executed, all five implant sitesare mapped

at the time of treatment planning andsurgery. There are reasons for this

treatment approach.



A

B C DE



Give the patient the

chance tochange histreatment

plan.

A patient maydesire a

completelyimplant-

supportedrestoration (e.g.,RP-4 or FP) but

cannot afford thetreatment all at

once.

If an implantcomplicationoccurs, the

preselectedoption sites permit

repeatablecorrective

procedures.

• Th dib l d t i t least 12 mm



• The mandibular overdenture requires at least 12 mmbetween the soft tissue and the occlusal plane to provide

sufficient space (15 mm from bone level to occlusal plane) for

the bar, attachments,

and teeth.





OD-1



Patient

selectioncriteria for:

OD-1

Opposinga maxillary

fulldenture

Anatomicalconditions are

good to excellent(division A or Banterior and

posterior bone

Additionalimplants willbe inserted within 3

years

Cost is the primary

factor

Edentulousridge not square with a tapered

dentate arch

form

Posteriorridge form isan inverted U

shape

Patient’s needsand desires are

minimal,

primarily relatedto lack of prosthesisretention



B D



•Independent implants

in the A and E positions

allow a greater anterior

rocking of therestoration and place

greater

leverage forces against

the implants.



OD-2D-2



Patient selection

criteria for: OD-2



Opposingarch is a

maxillarydenture.

Posteriorridge

forms aninverted

U shape.Patient’sneed and

desires areminimal,

primarilyrelated to

lack ofretention.

When the patient isunable to insert

additional implants

within a short time

frame (within 3 years), an OD-2 issafer

than an OD-1independent implant

approach

Anatomical

conditions are goodto excellent (division A or

B bone in anteriorand posterior

regions).

The mandibular

residual ridgeform is square to

ovoid, and

The dentatearch form is

square toovoid.



implants in the B and D positions,and a bar joins the implants.

Attachments such as an O-ring ( A)

or a Hader

clip ( B), which allow movementof the prosthesis, can be added

to

the bar. The attachments are placed

at the same height at equal

distances off the midline and

parallel to each other.



Bar splinting the A andE positions will flex five

times more than a bar

connecting implants inthe B and D positions.

As a consequence,

screw loosening risk isincreased



The connecting bar between

implants B and D

should not be cantilevered to the

distal.

The Hader clips in the prosthesis do not allow

prosthesis movement.

Hence, this is a

PM-0 implant overdentureand will cause repeated

biomechanical

complications.

I l i A d E i i



Implants in A and E positionsnever be splinted

Implants joined with straight bar are

lingual to ridge:

• Difficulty with speech

• Anterior tipping of overdenture

• Five times greater bar flexure than B

and D positions.

Implants are joined with anterior curved bar.

• Greater bar flexibility (nine times the

B and D positions)

• Increased screw loosening

• Increased moment forces on anterior

aspect of prosthesis



Splinted Implants in the A

and E Positions lead to:

Implants joined

with straight bar

are lingual to

ridge result in

Difficulty with

speech andanterior tipping

of the denture



When O-rings are

used for OD-2, theattachments

are placed parallel

to each other andat the same

occlusal

height.



OD-3



Opposingarch is amaxillarydenture.

Patient mayhave moderateforce factors

(e.g.,parafunction)

Patient’sneeds and

desires requireimproved

retention,support, and

stability

Cost amoderate

factor

Anatomical conditionsare good to excellent

(division A or

B bone in anterior and posterior regions).

The mandibularresidual ridge formis square to ovoid,

and



Advantages of Splinted A, C,

and E Implants

• Less screw loosening

• Less metal flexure

• Less stress to each implant compared with Aand E implants

• More implants Greater surface area

•

Less prosthesis movement• One implant failure still provides adequate

abutment support



The connecting bar between

implants in A, C and E

positions

The attachmentsshould be positioned

to allow movement of

the distal section of the prosthesis.(o-ring is

recommended)



OD-4

Patient’s



Opposingnaturalteeth

needs anddesiresrequire

improved

retention,support,

andstability

Increasethe CHSUnfavorable

force factors(parafunction, age, crown

height space>15 mm)

C – h bone volume

Patient selectioncriteria for:

OD-4



OD-4

four implants are

placed in the A, B, D,

and E positions. The

implants providesufficient support for a

distal

cantilever.



OD-5

Patient’s



Opposingnaturalteeth

needs anddesiresrequire

improved

retention,support,

andstability

Increase theCHS

Unfavorable

force factors(parafunction, age, crown

height space

>15 mm)

C – h bone volume

Patient selectioncriteria for:

OD-5



OD-5implants are placed

in the A, B, C, D, and

E positions. A barsplints the implants

together

and is distally

cantilevered. Thelength of the

cantilever depends

onthe anteroposterior

distance and the force

factors.



A-P spread rule for cantilever

A-P spread

It is the distance

from the middle ofthe most anterior

abutment to the

distal aspect of themost posterior

abutment.



A tapered arch

form has thegreatest A-P

distance, larger

than 8 mm incomparison with

ovoid and square

arch form



Abutments designed

for attachment-retained restorations



magnets



Locator abutment

components and

instruments



Locator

abutment withdifferent

gingival height.

Processing cap



Locator inserts that

is color coded come

with five different

retentive holding

force levels

Locator

abutment

pick up

Locator

Analog



Locator Core

Tool



1. Locator Abutment Driver

for tightening of

abutment.2. Locator Insert Seating

Tool for seating an insert

into the titanium processingcap.

3. Locator Insert Removal

Tool for catching and pulling

the used insert out of the

permanent metal housing.



Block out spacer

Torque wrench



Clinical and

Laboratory procedure

for locator abutment



Abutment selection

The highest level of tissue

measured with the AbutmentDepth Gauge. This will allow

the retention groove to be at

the appropriate supra gingival

height.



Abutment selection

Please use extreme caution when measuring that you

do not add any additional

height to yourmeasurement.Order

exactly what you measure.

Measure 1mm = order1mm cuff

i t ll ti



Abutment installation

Install the Locator Abutment into the

implant manually.

Manually seat the abutment

using the Locator Abutment

Driver part of the Locator Core

Tool.

Fi l ti ht i



Final tightening

With torque

wrench with

recommend

ed torque25 N/cm



attach the Locator Abutment Pick-up to

each Locator Abutment.

The pick-up should have

stable friction retention.

Take the abutment-level impression



Take the abutment level impression

in a customized impression tray

with an elastomeric impression

material.Remove the impression once the

impression material has set.

The black processing inserts of the



The black processing inserts of the

pick-ups should be clearly visible

within the impression. Send the

impression to the laboratory.

Place the abutment locator replica in



Place the abutment locator replica in

the locator abutment pick up then

pour the impression with stone to

have the working model

Pl h



Place the spacer over the head of each Locator

Abutment Replica providing primary soft tissue

support and a resilient situation. process and cureit into the overdenture.

Remove the overdenture and discard the spacer after

the acrylic has cured.

S d h fi l d i h h



Send the final overdenture with the

Locator Processing Cap and insert to the

clinician.



Converting an

existing denture chair

side

Pl h h h d f h



Place the spacer over the head of each

Locator Abutment providing primary

soft tissue support and a resilientsituation. Firmly attach the Locator

Processing Cap.



Mark the top of the Processing Cap

using indelible denture pencil,pressure-indicating paste, etc.



Use an acrylic laboratory burr to

relieve the denture base in theindicated areas

V t i t t t ll th



Vents are important to allow the

escape of excess material



1st

Pt. to closegently to align

occlusion

2nd Pt. to remain open till

complete curing



Evaluate the pick up

1- check that

both attachment

are picked-up2-No voids

3- voids are

correctable if

the attachment

does not move

4-trim the excess



Remove Spacer from the Locator

Abutment. Remove the Processing

Insert from the Processing Cap in the

overdenture using the Locator Insert

Removal Tool.



Press the preferred Locator insert into the

Processing Cap’s metal housing, using theInsert Seating Tool.

Gradual loading is always recommended.





Components of ball attachment



Components of ball attachment



May be straight or angled

zest anchors develop

new saturno™ narrow

diameter implantsystem that have

straight and angled ball

attachment.



Magnetic attachment

• Magnet assembly

placed in denture and

flat keeper onabutment.

Advantages for magnetic



Advantages for magnetic

retainer

1. Not affecting the

denture path of

insertion2. Self-seating

denture

3. Maintenance issimpler



disadvantages

1. Less retention

intra oral

2.corrosion(which iscan be treated be

electroplating)





The color coded PPM Bar patterns are pre-

milled in 0 degree,

2 degree and 4 degrees.

The PPM plastic bar patterns burn

out clean without residue. 0, 2 or 4 degreemandrels are used to place the

PPM Bars in the desired path of insertion.

Corresponding carbide burs

are used to finish the casting. The Titanium

PPM 0 or 2 degree bars were designed

for laser welding.

Plastic pre-milled bar system PPM)



H d EDS B S t



Hader-EDS Bar System

The Bars plastic bars,

Titanium Bars for laser

welding and Gold Barsfor soldering or laser

welding

are now available.

The Housings:

The Clips:

The durable



The Housings: The gold-plated

machined metal Hader-EDS Housing simplifies

clip replacement and

prevents loosenesscaused by acrylic

breakdown.

The Clips: The durable

Hader-EDS Clips are

interchangeable with standardHader Clips and are available

in three color-coded levels of

retention.



The Analogs and

Impression Clips:• Plastic Hader-EDS

Impression Clips

•aluminum Hader-EDS

Bar Analogs are available

for the fabrication of

processing Models.



Clinical and

Laboratory procedure

for Bar abutment

Abutment height



g

selection



Remove thehealing abutment

Screwing the

abutment



Tighten the

uniabutment

pick up

Take theimpression



Screwing the

abutment

analoge to

have the

master model

Place the Semi



Place the Semi-

Burnout Cylinder on

the replica and

tighten it with a

Laboratory BridgeScrew. The plastic

part of the cylinders

are cut back toappropriate

dimensions.

Reduce the bar height, leaving a minimum of



g , g

2.5 mm to ensure a proper fit of the inserts.

Note: Do not grind the retention surfaceof the bar.

Attach the bar to the plastic sleeve with a

material that has a low polymerizationshrinkage.(duralay)

Processing



ocess g

Apply casting sprues

outside the functionalareas of the bar.

Invest, burnout and cast

with an appropriate metalalloy according to

standard working

procedures.

If we have metal bar



If we have metal bar

Investingsolderingthen



Finish and thoroughlypolish the bar. Protect the

margins of the cylinders

during grinding andpolishing by using the

Polishing Protectors.

Single screw test for passive fit



Single screw test for passive fit

Spacing and blocking



Place the bar restoration on the

UniAbutment Replicas and tighten withthe Laboratory Bridge Screws. Press the

green plastic spacer onto the bar.

The spacer is used to enable positioning

of the Profile Bar Insert after

polymerization of the overdenture.

Block out the undercuts and

leave the spacers free. Cover the upper

free areas of the bar and theSemi-Burnout Cylinders

denture processing



Place the housings on the

spacers before investing of theoverdenture. Make sure the

housings are fully seated.

Process the acrylic resin and

finish the prosthesis as usual.



InsertingInstall the Profile Bar

Insert into the housing

with the suppliedInsertion Tool. The

Profile Bar Insert should

snap in audibly.

Matainance the bar



Matainance the bar



Documents

mandibular overdenture (2).pdf