Classification and impression techniques of implants By Dr.K.V.Anitha (PG Student) Student)
Classification
1. 2. 3. 4. 5. 6. 7. 8.
Based upon Placement within the tissues Materials used Attachment mechanism Surface coating Shape Surgical stage Mode of insertion Tissue response & systemic toxicity effects of implants
Based upon the placement within the tissue
Subperiosteal implants
Subdivision of subperiosteal implant Unilateral o Interdental o Total o circumferential o
Unilateral subperiosteal implant
Interdental subperiosteal implant
Total subperiosteal implant
Circumferential subperiosteal implant
Transosteal implant
Also known as
Staple bone o Mandibular staple o Transmandibular o
Transosteal implant
Endosteal
implant
Root
form
Blade/plate form
Ramus
frame
Intramucosal inserts
Endodontic
stabilizer implant
Based upon materials used 1.Metallic implantsimplants-commercially -commercia commercially lly pure titanium Titanium alloy Cobalt chromium molybdenum alloy 2.Nonmetallic implants implants--Ceramics -Ceramics Carbon
Ceramic and titanium alloy implants
Based upon the attachment mechanism 1.Osseointegration 2.Fibro osseous integration
Based upon their surface coating Titanium plasma sprayed o Hydroxyapatite coating o Grid blasting with TiO o SLA(sandblasted SLA(sandblasted--largegrid -largegrid largegrid--acidetched) -acidetched) o Acid etched o Machined surface o
Based upon the shape
Contd. o o o o o
Threaded,nonthreaded Tapered,parallel With vent holes,without vent holes Hollow cylinder,solid screws Root form,blade form
Based upon the surgical stage Two stage implants
One stage implant
Based upon mode of insertion
1.Axially inserted (crestal approach)
2.Laterally inserted(basal approach)
Based upon tissue response &systemic toxicity effects of implants o
Biotolerant materialsmaterials-polmethylmethacrylate -polmethylmethacrylate
Bioinert materialsmaterials-titanium -titanium and aluminium oxide materials-glass -glass and calcium o Bioactive materialsphosphate ceramic o
Components of implant
Implant body
Cover screw
Healing abutment
Healing cap
Implant abutment
Impression posts
Laboratory analogs
IMPRESSION MA MATERIALS TERIALS Ideal Requirements Complete
plasticity before
cure Fluidity Ability Ability
to record fine detail
to wet oral tissues
Dimensional
accuracy
Dimensional
stability
Complete Optimal
elasticity after cure
stiffness
Materials Used
o Alginat e o Agar o Polysulphid e o Poly ether o Cond ensation Silicon e o Addition Silicon e
ALGINATE
Poor dim dimensional nsional stability stability o Poor Poor dim dimensional nsional accuracy accuracy o Poor Poor t t ear ar str str ength o Poor Poor stiffn stiffn ess o Poor of gypsum gypsum o Int erf er es with s etting of
AGAR o
Interferes with setting of gypsum
o
Dimensional instability
o
Elaborate equipment needed
o
Low tear resistanc resistance e
Polysulphide
o Base Base-pol -polusulf usulfide ide polymer, polymer, CatalystCatalyst- lead dioxide dioxide o High tear strength o Messy,unpleasan Messy,unpleasantt odour o Long setting time o Poor dimensional stability o Hydrophobic
Condensation silicone
o Cheaper o Good tear strength, accuracy & elastic properties o Dimensional instability,due to loss of ethyl alcohol o Poured quickly
Addition silicone
o Shorter setting time o Easy to mix mix-- autom automatic atic mixin mixing g devices devices o Adequate tear strength o Extremely high accuracy o Dimensional stability even after 1 week o Least distortion on removal o Hydrophilic o Good compatibility with gypsum
Polyether
o Good dimensional stability & accuracy o Short setting time o Material very rigid o Not available in all consistencies o Most expensive
Dispensed as :
l m mixing Manual
Automixing sy st em
Manual mixing
o Putty o Heavy body o Monophase o Light body
Automixing equipment equipment & materials
Two
basic impression techniques for implants are
1. indir indirect ect techniqu technique e or or closed closed tray tray technique technique 2.direct or pick-up or open tray technique.
Indirect impression technique
Contd
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Direct
impression technique
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Indirect method
Direct
method
Related Tautin(1985)presente autin(1985)presented d
articles
a technique t echnique to accurately, transfer and reproduce the relationship between implant dentures dentures , in which no preliminary impression impression or acrylic resin custom tray were needed. He used modeling compound compound to form a custom tray by adapting it over transfer copings,pressing the compound over the superior aspect aspect of the coping so that its circular outline is seen through the compound.After trimming the outline of the coping showing through the top of the tray an impression plaster is used to record and transfer the coping to the impressions
Loos(1986)presented Loos(1986 )presented a detail technique for the
fabrication of of a fixed prosthesis supported by implants.His technique incorporated incorporated plugging the th e incisal end of the transfer coping with beading wax(to prevent impression material from flowing into it)splinting the transfer copings with orthodontic ligature wire and Duralay acrylic resin,use of a plastic perforated impression tray with incisal window to access the transfer coping and making the final final impression with putty light light body addition silicone.
Rasmussen(1987 asmussen(1987)presented )presented
a technique in which the existing denture is modified using tissue conditioning material is used instead of healing caps after second stage surgery ,eliminating the use of impression copings at the final impression.
Humphries et al (1990) evaluated the accuracy of implant master casts constructed from transfer impressions using three techniques.The techniques used were splinted square polymer copings,unsplinted square polymer polymer copings and unsplinted hydrocolloid copings.Tapered hydrocolloid copings copings were more accurate than the other two methods.
Carr (1991) compared impression techniques for five implant mandibular model by both indirect and direct transfer coping techniques and found that for the models used ,the direct method produced more accurate working casts.
Vigolo et al(2000)evaluated al(2000)evaluated the accuracy in transferring the position of the hexagonal hex agonal head of a single implant to the working cast, and concluded that the sandblasting and coating the roughened surface of the impression coping with an impression adhesive will will result in more accurate orientation of the implant replicas in the laboratory master casts in single tooth implant restorations.
Conclusion Success with implant prosthodontics requires a careful attention to each and every step from diagnosis and treatment planning. Several implant systems are available , selection of appropriate one is mandatory. The prosthesis fit can be accurate only if a proper impression is made. Thus usage of correct impression technique and material are important.
References 1. contemporary implant dentistry , Carl E. Misch 2. Implants in dentistry , Michael,John and Luis. 3. Implant prosthodontics Stevens & freidrickson freidrickson 4.
Denta entall
implantsimplant s- Funda Fundament mental al & advanced advanced laboratory laboratory technology , Robert Winkleman &Kenneth orth.
References
contd
5. Philips science of dental materials 6. Contemporary fixed prosthodontics, Rosentiel 7. Principles & practice of implant dentistry, Weiss 8. Theory & practice of ossteointegration, Hobo 9. Carr AB. Int J Oral Maxillofac Implants. 1991;6(4):448-55 1991;6(4):448-55 10. Assif etal. Int J Oral Maxillofac Implants. 1999;14(6):88588 11. Loos Larry G. J Prosthet Dent 1986;55:232-42 12. Rasmussen Eric J. J Prosthet Dent. 1987;57:198-20 1987;57:198-203 3 13. Tautin Francis S. J Prosthet Dent. 1985;54:250-5 1985;54:250-51 1
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