Raju introduction of implants/cosmetic dentistry courses
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Introduction of implants
INDIAN DENTAL ACADEMYLeader in continuing Dental Education
Introduction Implant componentsClassification of implantsImplant Surface coatings Implant Abutments Implant AttachmentsConclusion References
Loss of teeth, eventual edentulism, and wearing of complete dentures have been part of expected course of aging by general population.
Incidence of edentulism in western world has posed challenge to Prosthodontists & Oral surgeons, encouraging them to devise acceptable prosthetic results for patients.
Components of implant
Cover screw Healing abutment
Implant abutment is the intermediate connector between the implant and the restoration, it may extend above the tissue. In some instances is subgingival, to provide a more esthetic restoration.
Classification of implants
BASED UPON THE PLACEMENT WITHIN THE TISSUE
Root form Blade/plate form
Endodontic stabilizer implant
Based upon materials used
1.Metallic implants- Commercially pure titanium Titanium alloy Cobalt chromium molybdenum
2.Nonmetallic implants- Ceramics Carbon
Based upon the attachment mechanism
2.Fibro osseous integration
Based upon their surface coating
1. Titanium plasma sprayed2. Hydroxyapatite coating3. Grid blasting with TiO4. SLA(sandblasted-largegrid-acidetched)5. Acid etched6. Machined surface
Cylindrical Screw shaped implants.
Threaded Non threaded.
Based on shape
Based upon the surgical stage
Two stage implants One stage implant
Based upon tissue response
o Biotolerant materials-polymethylmethacrylate
o Bioinert materials-titanium and aluminium oxide
o Bioactive materials-glass and calcium phosphate ceramic
•Tendency for slippage
•Bonding is required
•No slippage tendency
•No bonding is required
Threaded implants :
Alteration in the design, size and pitch of the threads can influence the long term osseointegration.
Advantages of threaded implants
More functional area for stress load distribution than the cylindrical implants.
Threads improves the primary implant stability avoids micromovement of the implants till osseointegration is achieved.
Roughness parameter (Sa)0.04 –0.4 m - smooth 0.5 – 1.0 m – minimally rough 1.0 –2.0 m – moderately rough> 2.0 m – rough
Weinerberg – moderately rough implants developed the best bone fixation
In vivo studies Smooth surface < 0.2 m will – soft tissue no
bone cell adhesion clinical failure.Moderately rough surface more bone in contact with implant better osseointegration.
Advantages of moderately rough surface :
Retention of the fibrin clot, osteoconductive scaffold, osteoprogenitor cell migration and faster osseointegration.
Increase rate and extent of bone accumulation contact osteogenesis
Increased surface area renders greater osteoblastic proliferation, differentiation of surface adherent cells.
Increased cell attachment growth and differentiation.
Increased rough surfaces :
Increased risk of periimplantitis
Increased risk of ionic leakage / corrosion
10 A in milliseconds100 A in minute2000 A in 6 years
Additive surface treatment :
Titanium plasma spraying (TPS) hydroxyapatite (HA) coating
Substractive surface treatment :
Blasting with titanium oxide / aluminum oxide and acid etching
Modified surface treatment :
Oxidized surface treatment
Machined / turned surface
SEM x 1000 SEM x 4700
Surface roughness profile 5 m
Titanium plasma sprayed coating (TPS)
6-10 times increase surface area.
Roughness Depth profile of about 15m
15000-20000 degrees c3000 m/ sec
HA coated implant bioactive surface structure – more rapid osseous healing comparison with smooth surface implant.
Increased initial stability
HA coatings often exhibit cracks or even complete loss of HA coating and heavier colonisation of microorganisms
Sand blasting large grid Acid etching ( SLA )
Sand blasting – surface roughness (substractive method)
Acid etching – cleaning
SEM 1000X SEM 7000X
Decrease in contact angle by 100 – better cell attachment. Acid etching with 1% HF and 30% NO3 after sand blasting – increase in osseointegration by removal of aluminium particles (cleaning).
Wennerberg et al superior bone fixation and bone adaptation
Laser induced surface roughening
Eximer laser – “Used to create roughness”
Regularly oriented surface roughness configuration compared to TPS coating and sandblasting. Physiologically mimic natural trabecular bone
SEM x 300
SEM x 300SEM x 70
The clinical advantages of coatings:-
1. Increased surface area.2. Increased roughness for initial stability. 3. Stronger bone to implant interface.
DISADVANTAGES OF COATINGS:-
1. Flaking, cracking, or scaling upon insertion.2. Increased plaque retention above bone.3. Increased bacteria and nidus for infection. 4. Complication of treatment of failing implants5. Increased cost.
Portion of implant that supports and retains a prosthesis or implant super structure
Abutment consists of 3 constituents which may be unified or separate
1. Base – fits into antirotational component2. Head – protrudes permucosally and serve
as prosthetic retainer3. Retaining screw – which affixes to
TYPES Depending upon retention1. Abutment for screw retention2. Abutment for cement retention3. Abutment for attachment
Depending upon angulation1. Straight abutment 2. Angled abutment
Depending upon design
1. Flat topped abutment 2. Tapered shouldered abutment3. Direct gold copings
Commercially available1. Ceraone abutment2. Ceradapt abutment3. UCLA abutment4. Noble bio care abutment5. Estheticone abutment6. Noble pharma single tooth abutment7. Astra abutment
Retention– resist removal of the retainer along the path of insertion
Resistance – opposes movement of the abutment under occlusal loads and prevents removal of restoration by forces in apical and oblique direction
Retention decreases as the taper is increased from 6-25 degrees • Ideal taper is 2-5 degrees• Parallelism of axial walls has been recognized to be single most factor
for retention• Eames et al – found that clinically acceptable preparations present a
taper of 20 degrees
Abut ment sur f a ce are a
The r e i s l i ne ar i nc r ease i n r et en t i on as t h e di am et er i nc r ease f or pr epa r at i on wi t h i de nt i ca l hei ght
A tall preparation offers greater retention than a short abutment
Increase in height – increases surface area , increased resistance to lateral forces
Height of the abutment must be greater than the arc of rotation
Arc of rotation decreases when grooves are prepared in abutment
Abutment surface roughness
1. Surface roughness increases the retention of a restoration by creating micro retentive irregularities into which the luting agent projects
2. Surface roughness retention is dependent upon the type of burs and the thickness of luting agents
3. Internal aspect of the casting should be air abraded with 50 micro meter alumina to enhance retention by 64%
Path of insertion
NON PARALLEL ABUTMENTS
Angle less than 20 degrees
Anti rotational features of implant systems
Anti rotational features on implant inhibit unwanted movement of their overlying abutments. Anti rotational components in current use include
External hex, Internal hex, Spline type interface, Morse taper
Antirotational features of abutments External hex Most widely available Found on top of abutments Hexagonal geometry
Internal hex Provides more precise implant
abutment interface Seats the abutment into hexagonal
SPLINE ATTACHMENT Splines are fin to groove anti rotational design Consist of six external components called tines which
protrude 1mm from implant and are matched to a female embedded in a abutment base
MORSE TAPER ATTACHMENT
Consist of 1 piece abutment post with 5 degree taper Resist rotation and even removal Also referred to as cold welded design
Guidelines for abutment selection
Depth of soft tissue
Measured with periodontal measuring probe
labial margin of abutment is atleast 1mm subgingival
Diameter close to that of cervical margin of tooth
Emergence profile Need atleast 3mm of vertical space from implant head to
gingival margin Allows gradual transition from implant head
Ideally implant is placed close to the long axis of missing tooth.
Small degree of labial angulation – easily accomodated with standared abutments
If more labial angulation needed – use of standard abutment leads to
1. Excessively contoured labial surface 2. Porcelain surface too thin to mask metal structure
Space from implant head to opposing tooth Vertical space of 6-7 mm – standard abutment 5mm of space – preparable abutment Less than 5mm of space – vertical dimension of occlusion
increased, deeper implant placement
CEMENT RETAINED ABUTMENTS
1. superstructures are more passive2. Easier to obtain esthetics3. Fewer porcelain fractures 4. Common procedure and economical5. Manipulation in posterior region is easier with cement6. Loosen less often compared to that of screws7. Progressive loading8. Less fatigue9. Abutment-crown crevice10. cost
1. When permanent cements are used evaluation and maintainence of implants is difficult
2. Difficult to retrieve unless soft cements are used3. Temporary cements wash out prematurely4. Greater abutment height required5. Less resistance to tensile forces
Types of abutment for cement retention
1.Single unit or one piece abutment 2 .Two piece abutment
1.Single unit or one piece abutment does not engage anti rotational hex
but fits flush with the implant platform
2 . Two piece abutment has one component to engage anti
rotational hex of implant body and other component to fixate the abutment and implant body together
SCREW RETAINED ABUTMENTS
1. Low profile of retention2. Reliable security when mesostructure bars of of limited
vertical dimension are used3. Space for denture teeth 4. No risk of cement in the sulcus5. Easily retrievable
FACTORS THAT AFFECT SCREW CONNECTION
1. misfit2. poor abutment screw tightening3. excessive occlusal loading4. inadequate screw design Misfit has been reported to be as high as 1. 66 micrometer between implant and abutment in
vertical direction , 2. 99 Micrometer in horizontal dimension
Abutment for attachment
• Uses an attachment device to retain a removable prosthesis • Includes Mesostructure bars – continuous and non continuous Super structure attachments – magnets ,, hader clips of plastic or
gold , zest anchors ,o - rings , ERA attachments.
Indicated for replacing single tooth for large prosthesis upto full arch.
Used only when emergence profile are parallel
If abutments are not parallel – can be prepared by
1. Direct method 2. Indirect method
1. Available in angulations from 10-30 degrees
2. Improved esthetics 3. To correct path of insertion 4. Increase in angle – increase risk of
fracture 5. Difficult to manipulate6. Multiple small parts increase
possibility of component looseening
ABUTMENT DESIGNSFLAT TOPPED ABUTMENTUsed to support bars for overdentures/ fixed detachable hybrid
prosthesis Do not engage antirotational component advantage – simplicity disadvantage - does not have counter rotational forces-
unsuitable for single tooth replacementStraight emergence profile- unesthetic in anterior maxilla
TAPERED SHOULDERED ABUTMENT Indicated in – bars to overdentures, hybrid overdentures,
single tooth replacement Tapered design-resistance to lateral forces is enhanced Lower profile abutment collars- subgingival margin –
esthetic Tapered shoulder- angled at 9-15 degree thus allowing
divergence between implants 18-30 degrees
DIRECT GOLD COPING
Coping bypass abutment entirelyConsists of two parts- coping and screw Porcelain is baked directly on to coping – results in crown
which attaches directly to implant bodyCoping engages antirotational component of implant Indications1. Single tooth restorations2. Limited interocclusal space3. Where subgingival margins are required
• CeraOne abutment is designed to accept a cementable ceramic core restoration
• The most frequently used abutment for single tooth restorations is the CeraOne abutment.
• Clinicians have found that these abutments yield good esthetic results and have safe, fast and easy handling.
• Abutment available in 5 heights – 1,2,3,4,5 mm
Ceramic cap –available in cylindrical form for posterior arch and tapered form for anterior arch that fits over ceraone abutment
Cap- made up of densely sintered semi translucent aluminium oxide which is designed to be fused with porcelain and cemented permanently to abutment
In posterior areas- ceraone abutment is used with ceramometal coping
Since esthetics may not be critical in posterior areas, plastic wax up coping is used to fabricate ceramometal coping with or without access channel to which porcelain is fused
To facilitate during troubleshooting , a lingual removal button is designed
A narrow occlusal access channel can also be fabricated in gold to facilitate reentry
Noble biocare abutment hex shaped,tapered sides features a female hex which
interface with implant male hex head and is secured by a titanium abutment screw
Indicated in multiple implant situation without causing esthetic compromise with the metal display
Designed to allow esthetic veneering material to be placed subgingivally
Abutment available in 1,2,3 mm collars
All ceramic alternative to metal abutments
Pre machined precision milled abutment made to fit the implant hex
made up of densely sintered 99.8% pure aluminium oxide which are pressed into desired shape and subjected to sintering temperature of 2050 degrees Celsius
pore free strong wear resistant stable bio ceramic material
A great advantage of the CerAdapt abutment is that it allows a better emergence profile, because it is wider in its cervical portion, and it also enables the differentiation in the gingival finish line of the preparation.
This line accompanies the concave arch of the marginal gingiva, differentiating the heights of the mesial and distal regions
Andersson and Oden showed flexural strength of 690 MPA and demonstrated that the abutment can withstand tremendous loads without fracturing
It is a non metallic , non corrosive , bio compatible. soft tissue response is excellent
Tooth colored and light diffusion property – more natural and esthetic implant crown
Used for implant supported single and multiple tooth restoration in the anterior canine and premolar regions
Can be either screw or cement retained
Most adaptable and versatile abutment for very restricted working area
Improved esthetics Abutment can be custom
reangulated All abutment have a non rotating
configuration Improved emergence profile
Each restoration has a tapered interface similar to that of a standard FPD restoration
Multiple butt joint prosthesis interface avoided Lingual screw retention for fixed retrievability - practical
CUSTOM REANGULATED UCLA ABUTMENT
Eliminates need for prefabricated angled abutment Simplifies construction Results in better esthetics When implants are not parallel , parallelism can be
Secured with titanium abutment screw Pre machined internal hex interfaces with implant male hex
provides maximum resistance to lateral forces and screw loosening
Lingual surface of abutment is tapped to receive a gold screw – fixed retrievabiltiy
BRANEMARK SYSTEM SINGLE TOOTH ABUTMENT
Developed by Noble pharma Designed to adjust access hole
position,prosthetic screw angulation Improved esthetics
• Presented with the option of 20 or 40 degree tapered top• Used for fixed bridges / over dentures
Computer generated Procera abutment
• Custom abutment-designed by a computer and machined to exact specification
• Head of implant impression made and working model is placed in the scanner
• Readings of implant angulation and position are taken Using cad-cam software,ideal abutment is generated• Advantages
Precise fit Ideal emergence profile Improved esthetics Proper restoration contours
• The computer-assisted design system uses a die scanner and a computer, which converts the digital information obtained by scanner into a three dimensional image.
• This image reproduces, with high fidelity, the contours of the dental preparation on a computer screen.
• After the data is processed it is possible, by using a specific software, to manipulate this preparation, defining the margins, establishing uniform coping thickness, emergence profile, and internal space thickness for the cementing agent and other details.
• The data is sent via modem to coping manufacturing facility.
Abutment try-in kit Provide replicas of abutment types that can greatly assist
abutment selection Tried intraorally or on a cast Made up of aluminium – not damage the implant Color coded for easy recognition Used for better screw access position ,marginal height and
Removal of a fractured implant abutment screw
Implant repair kit :a. Center bit b. 1.3mm twist drill c. 1.9 mm twist drilld. Conical instrument to retrieve the fragment e. Manual tapping instrument
Many edentulous patients experience problems with their dentures,
especially lack of stability and retention, together with a decrease of chewing ability.one possibilty of solving this problem is the use of endosseous implants to which an overdenture can be attached.
The overdenture approach facilitates the fabrication of different types of prostheses depending on the number of implants placed. They are• Implant-supported fixed screw-retained prosthesis • Implant-supported removable overdenture • Combined implant-retained and soft tissue-supported
Definition of attachment
A mechanical device for the fixation, retention, and stabilization of a prosthesis
Attachments used to retain overentures
• Ball attachments• O – ring• ERA attahcment system• Spheroflex
• Locator attachment system• ZAAG attachment system• Bars
• Dolder bar• Hader EDS bar• Hybrid bar system
• Resilient• Rigid
The decision as to what type of overdenture is given is determined by the following1. Patients expectations2. Financial considerations3. Anatomic and morphologic condition of the bone4. Shape of the alveolar ridge
Attachment selection based on number of implants and choice of prosthesis
Categorization of potential implant site in mandible – By Carl E Misch
• Supported by free standing implants in the B and D position.
• Implants are independent and not splinted
• Indications• Indicated when cost is the significant factor• Anatomical conditions are good• Ideal anterior and posterior ridge forms• When patients needs and desires are minimal
• Most common type of attachment used is a Ball, ring type attachment. Eg: - O-Ring
ERA attachment Spheroflex
O – ring attachment
• They are doughnut shaped, synthetic polymer objects that posses the ability to bend with resistance and then return back to their original shape.
• The O-ring attaches to a post with a groove or undercut area.
• Ease in changing the attachment• Wide range of movement• Low cost• Different degrees of retention• Elimination of time and cost
• Resilient precision overdenture attachment
• Universal hinge with vertical movement
• Metal jacket which holds the male attachments
• Four angles to accommodate divergent implants (0, 5, 11, 17 degrees)
• Two types standard and micro. Selected based on interocclusal distance.
The Sphero Flex is a self paralleling combination titanium implant abutment and ball attachment. It is the ball attachment of choice for all implants.
Self paralleling Implant abutment overdenture system with 2.5mm sphere.
Free rotation of 7.5º for one abutment, 15º degrees for more than one.
Loactor Implant attachments
Supraradicular design which comes in a straight abutment
2 angle connections of 10 and 20 degrees for angled abutments.
Total height is 3.5 mm
• The Self-Aligning feature of the LOCATOR attachment allows a patient to easily seat their overdenture
• Different retentive males that allow for choice of retention according to need of patient
Indicated when1. Interocclusal height is deficient
• Locator female component on implant
• Male component placed on the female component
Zaag attachment systems
• In 1972 Zest anchor was introduced to the dental profession. Initially used as an attachment for overdentures on natural teeth.
• Later modified as ZAAG(Zest Anchor Advanced Generation)• Allows upto 15 degees of divergence in female orientation
• ZAAG implant abutment of different heights (3, 4, 5, 6mm). Female matrix of the system
• Male retentive element which will seat into the female matrix
Female abutments in place
Male retentive part seated
Male retentive part placed and cured in the denture base
Implants are positioned in location B and D and splinted together with a bar.
Indications:• patients needs and desires
are minimal• Patient can afford new
prosthesis and connecting bar
• Anatomical conditions are good
• Posterior ridge form is inverted u shape
• Developed by Hemet Hader in the late 1960’s.
• Modified by Staubli to EDS Hader system. Height of the EDS hader bar is 3 mm.
Plastic form of Hader bar Retentive clip placed on cast bar
Retentive clip being inserted into denture base
• Three root form implants are used. The superstructure connects the three implants
• Usually the first option• Patient expectations are
slightly high• Anatomical conditions are
good• Cost is not a major factor
• If posterior ridge form is good , implants are placed on A, C, E
• if posterior ridge is poor, implants placed in B, C, D regions.
Option four (Resilient Hybrid bar design)
Four implants are placed in A, B, D and E position.Indications • Poor posterior anatomy• Lack of retention and
stability• Soft tissue abrasion• Speech difficulties• Very high patient
• Attachments placed in the distal cantilever end and the midline.
• Anterior attachment must allow prosthesis to lift from the bar to permit rotation of distal attachments.
Indicated in patients who have 1. Poor posterior anatomy2. Attachment placed in the anterior section is a clip and in the
distal cantilever ball type attachments might be placed.3. Patient benefits because there is greater vertical support and
Zaag low profile bar attachment
ZAAG female part placed directly on the abutment
Male retentive element placed on the denture base
Loactor bar attachment
• Four evenly placed Locator female attachment cast on superstructure in overdenture option - four
• Four to six retentive elements are included in the bar design. Attachments usally used are Hader clips, O – ring, ERA.
• Typically four attachments are placed evenly. Two anterior and two posterior.
Option five (Rigid Hybrid bar design)
• Five implants are placed in (A, B, C, D, E).
IndicationsInability to wear conventional denturesVery high expectationsUnfavourable anatomyProblems with function and stabilityPosterior sore spots
Magnetic attachments ( jackson and shiner magnets )
Advantages:1. Simplicity of use2. Low cost3. Coercivity ( magnetism that does not fade away with time )
Disadvantages:1. Corrode when contact with oral fluids2. Permanent discoloration of denture base
1. Atlas of oral implantology – A.Norman Cranin 2. Contemporary implant dentistry – Carl.E.misch3. Implants in clinical dentistry – Richard.M.Palmer 4. Implant prosthodontics – Stevens Friedrickson5. Dental implants fundamental and advanced lab technology –
Winkelman6. Atlas of tooth and implant supported prosthodontics –
Lawrence.A.Weinberg7. color atlas of implantology – hubertus spiekerman
8. A positioning jig to verify the accuracy of implant abutments J prosthet dent 2002; 87; 115.9. A locating splint for placing implant abutments. J prosthtet dent 2004; 91; 97.10. Removal of a fractured implant abutment screw. J prosthet dent 2004; 91; 513.11. Do healing abutments influence the outcome of implant
treatment J prosthet dent 1998; 80; 193.12. All ceram crowns for single replacement implant abutments J prosthet dent 1997; 78; 486