Impression materials and recent advances.pptx

Impression Materials

1. IMPRESSION MATERIALS AND RECENT ADVANCES Presented By: Dr Muskan Agarwal

2. CONTENTS: Definition Classification of impression materials. Desirable properties. Non Elastic/Rigid Impression Materials Impression Plaster Zinc oxide Eugenol Paste Impression Compound Elastic Impression Material Agar Alginate Elastomers Digital imaging

3. DENTAL IMPRESSION A dental impression is a negative imprint of hard (teeth) and soft tissues in the mouth from which a positive reproduction (cast or model) can be formed. IMPRESSION MATERIALS Impression material is of liquid or semi-solid nature when first mixed and placed in the mouth. It then sets to become an elastic solid (usually takes a few minutes depending upon the material), leaving an imprint of person's dentition and surrounding structures of oral cavity.

4. DESIRABLE QUALITIES OF IMPRESSION MATERIALS: Biocompatibility: nonirritant,non allergic acceptable taste and odour should not absorb or dissolve in oral fluid Rheological Properties low viscosity viscosity should increase quickly pseudoplastic nature Mechanical properties: high elasticity and complete elastic recovery

5. Adequate compressive strength high tear strength high flexibility Thermal properties: low softening temperatures high thermal conductivity Physical properties good dimensional stability reproduction of details O thers economical easy to use

6. Theories of Setting 1. Colloidal Theory 2. Hydration Theory 3. Dissolution Theory( Crystalline theory)

7. ALGINATE: Elastic I rreversible hydrocolloid M ost frequently used dental material.

8. COMPOSITION OF ALGINATE : Ingredients % b y w t. Functions Sodium or Potassium or Triethanolamine alginate 15% Dissolve in water Calcium sulphate ( Reactor ) 16% Reacts with soluble alginates and form insoluble calcium alginate Zinc Oxide 4% Act as a filler particle Potassium Titanium Fluoride 3% Act as accelerator for the setting of a stone to be poured in impression to ensure hard, dense surface of a cast. Diatomaceous Earth 60% Also act as a filler , provide strength and stiffness Sodium Phosphate ( Retarder ) 2% Reacts with calcium sulphate there by retard the setting of impression Coloring and flavouring agent traces For the comfort of patient

9. APPLICATION : It is used for impression making when there are undercuts in mouth with excessive flow of saliva for partial dentures with clasp F o r m aki n g a p r eli m i n ar y i mp r e s s i o n f or complete dentures and treatment dentures. As a duplicating material.

10. DRAWBACKS WITH ALGINATE: P o or d i mens iona l s ta b ilit y ( i m bib i t i o n o r dessication is a problem). Low tear strength . Silica dust in the form diaomaceous earth. Poor adhesive with tray

11. ADVANCES IN ALGINATE IMPRESSION : Extended-pour alginate Tray adhesive for alginate High viscosity alginate Colour changing alginate Two paste alginate form Infection free alginate

12. EXTENDED -POUR ALGINATES Extended pour alginate is designed for use with alginate impression material which enables to delay pouring up impression under specified storage conditions. MILLENIUM ALGIN is considered an alginate of new generation alginate.

13. MILLENIUM : Class A type 1 alginate Tixotropic Extra-fast in-mouth minimum setting time 30 sec High accuracy: 15 micron Long dimensional stability (168 hours) Dust free 5 years of expiry date

14. M anufactured by LASCOD(Italy) STORING: The impression must be stored in a sealed plastic bag (Safe-Lock Bags by Lascod) without adding anything else. Do not leave the impression in open air or immersed in water. MILLENIUM working time can be extended when required with Personal Krono liquid. The liquid does not change MILLENIUM physical properties

15. 𝗈 Every drop of Personal Krono—20sec

16. TRAY ADHESIVE FOR ALGINATE liquid and spray containing polymide or diethylenetriamine polymer, ester gum and rosin in isopropyl alcohol or a combination of isopropyl alcohol with ethyl acetate has been introduced.

17. ACCUDENT XD TRAY ADHESIVE: N ew AccuDent XD Impression System creates impressions with dimensional accuracy and freedom from air bubbles and voids making it possible to create visibly better primary stone or virtual models.

18. DUST FREE ALGINATE: Sepiolite ,a natural mineral fiber containing magnesium silicate about 20microns was added to alginate as a substitute when added traps the alginate partiles thus reducing dust generation

19. COLOUR CHANGING ALGINATE: A combination of inorganic and organic(cresol red , naptholpthalein) along pH indicator has been incorparated . In such cases,the intial color of the alginate soon after mixing is a combination of pigment and Ph indicator where as the color of alginate after setting is the color due to pigment alone

20. TWO FORM PASTE ALGINATE : Q uite convenient to mix. Base paste contains a mix of soluble alginate, water and fillers. The reactor or catalyst paste contains calcium salt mixed with a viscous liquid that is non reactive towards calcium salt such as liquid paraffin. A pH stabilizing agent such as magnesium hydroxide is also added.

21. INFECTION FREE ALGINATE : qu a ter n ary bisquanidine a mm oni um compounds, co m p o u n d s , c h l orh e x i d i n e , dide c y ld i methy l a m mon i u m c h l o r id e w i t h out altering its properties.

22. COMMERCIAL BRANDS: Coe Alginate (GC America) Integra (Kerr) Jeltrate (Dentsply Caulk) Zelgan (DPI)

23. ELASTOMERIC IMPRESSION MATERIALS El astomers comprises a group of synthetic polymer based impression material that are chemically crosslinked when set

24. Advantages of elastomeric impression materials over the hydrocolloid higher tear strength dimensionally stable on storage. Most of elastomers can be electroplated

25. ELASTOMERS: Elastomers are of 3 types POLYSULPHIDE SILICONES Addition Silicones Condensation Silicones. POLYETHERS Light activated polyethers Chemically activated polyethers.

26. COMPOSITION OF POLYSULPHIDE Base paste Accelerator paste

27. PROPERTIES OF POLYSULFIDE Available in variety of viscosities (Light, Regular, Heavy, Putty) Working time = 3-6 min Setting time = 10-20 min. Highly flexible of all the elastomers. Elastic recovery improves with time . High tear strength. Not dimensionally stable Cast should be poured immediately. USED TO RECORD IMPRESSIONS FOR CROWNS, BRIDGES, INLAYS, ONLAYS AND PARTIAL DENTURES

28. ADVANTAGES: Good wettability Good surface detail High tear strength Long working time DISADVANTAGES: High permanent deformation Staining of clothes U npleasant rubbery smell Can only be used in a special tray Must pour within 1 hour

29. FREE POLYSULFIDE IMPRESSION MATERIAL lead-free, all-purpose rubber base impression material for inlays, crowns, bridges, full and partial dentures, rebasing and relining. Other commerical brands: Permlastic (Lead dioxide system) Omniflex (Copper hydroxide system)

30. CONDENSATION SILICONE IMPRESSION MATERIAL Alternate names: 1) Conventional silicones. 2) Room temperature vulcanizing (RTV) silicones. USED TO RECORD IMPRESSIONS FOR CROWNS, BRIDGES, INLAYS, ONLAYS AND COMPLETE DENTURES

31. COMPOSITION OF CONDENSATION SILICONE Base paste Accelarator paste

32. SETTING REACTION E xthother i c . Cross-linking occurs between the siloxane polymer and the alkyl silicate in the presence of the activator with the release of ethyl alcohol as reaction by-product. dimensional changes→evapariation of alcohol+polymeriazation shrinkage Alcohol could cause air bubbles in the stone cast.

33. PROPERTIES OF CONDENSATION SILICONE Available in all 4 consistencies Flow after 1 hour = 0.09% Mixing time = 1 min Working time =3 min Setting time = 6-10 min Good tear strength. Flexibility is less than Polysulphides. 8)Dimensionally not stable: Due to Polymerization shrinkage. Incomplete elastic recovery. c) Thermal contraction on removal from mouth to room temperature.

34. Advantages Adequate working time & setting time. Clean & pleasant odour. No staining. Adequate tear strength. Better elastic properties. 6) Can be electroplated with silver and copper . D sadvantages Lower flexibility than polysulphides Poor dimensional stability due to release of by products. Less accuracy if poured immediately Hydrophobic nature Poor to adequate shelf life (1- 2 years) Slightly exp e nsive.

35. Products available:- Accoe(GC) Cuttersil(Heraeus Kulzer) Speedex(Coltene Whaledent) Xantopren(Heraeus Kulzer) Silene(Bosworth)

36. ADDITION SILICONE IMPRESSION MATERIAL Have much better properties than Condensation silicones. Alternate names: Poly vinyl siloxane. Vinyl poly siloxane. Used to record impression FOR CROWNS, BRIDGES, INLAYS,ONLAYS, PARTIAL AND COMPLETE DENTURES

37. COMPOSITION OF ADDITION SILICONE Base paste

38. REACTOR/ACCELERATOR PASTE

39. PROPERTIES OF ADDITION SILICONE Available in all 4 consistencies. Various consistencies serve different purpose E.g. Putty or heavy body is used for primary impressions. Regular or light body is used for secondary impressions. 3) Excellent elastic recovery of 99.93% 4)Tear strength of 3500 gm/cm 5) Mixing time is 35-45 sec 6)Working time = 2-3 min. 7) Setting time = 6-8 min.

40. ADVANTAGES: Records highly accurate impression. Pleasant to handle. Shorter setting time. Excellent elastic recovery. No elimination of any by products. Dimensionally stable. Can be electroplated with silver & copper. Multiple die pour is possible. DISADVANTAGES More expansive with automatic mixing device. Shorter working time. May release H2 gas on setting. Hydrophobic material. Latex glove interfer setting reaction. Vinyl and nitrile gloves can be used

41. PRODUCTS AVAIABLE: Impressiv( Cosmedent) –truly hydrophilic 𝗈 Imprint 3 Penta (Putty impression material with automix) Aquasil/Reprosil/Hydrosil(Dentsply ) Exaflex/ Examix/Exafast/Hydroflex(GC America) Express, Imprint/Imprint II(3M ESPE) Flexitime(Heraeus Kulzer)

42. VINYLSILOXANETHER - IDENTIUM E xtremely hydrophilic, highly flowable, provides excellent resilience. y An accurate impressions in the narrowest crevices and high definition even in the moist sulcus. the advantages of polyether materials coupled with those of A-silicones Avaiable in medium viscosicty heavy viscosit light viscosity

43. EXAFLEX VPS IMPRESSION MATERIAL: EXAFLEX Vinyl Polysiloxane (VPS) impression materials produce crisp, extraordinarily smooth and precise impressions for models, crowns, bridges and dentures. Hydrophilic Immediate pour High tear strength Accurate impressions

44. FUTAR : 𝗈 T he convenient classic: hard A-silicone with convenient working time, accurate results and the utmost comfort. E xtra hard bite registration material ,easy to trim also with a scalpel

45. POLYETHER IMPRESSION MATERIAL Commercial names are Impregum, Remitec, Polyjel , Permadyne etc. Polyether is available in 3 viscosities (Light, Regular and heavy body)

46. PO L Y E TH E R: C omposition Base paste: Polyether prepolymer with terminal ethylene- imine groups. Fillers Plasticizers Catalyst paste • • • Aromatic sulfonic acid ester Fillers Plasticizers

47. PROPERTIES OF POLY ETHER : Can cause irritation due to presence of aromatic sulphonic acid catalyst in reactor paste. Elastic recovery =98.9% Permanent deformation is 1.1% Flexibility is low 2% Mixing time is 45 sec to 1 minute. Working time = 2 minutes. Setting time is 3-5 minutes. Good dimensional stability due to Addition polymerization reaction. Less polymerization shrinkage

48. ADVANTAGES • Accurate and fine details Good dimensional stability during setting Good elastic recovery of 98.9% Compatible with cast & die materials Pour within one week (if kept dry) Good wettability (hydrophilic) • • • • •

49. DISADVANTAGES • Stiff (difficult removal from the mouth) Expensive Short setting time (3-5 min) Bitter taste Absorbs water and changes dimension • • • •

50. Polyether is hydrophilic and can absorb water in wet condition (swelling), accordingly → Can not be electroplated → should be stored in dry environment to preserve its dimensional accuracy .

51. LIGHT ACTIVATED POLY ETHER IMPRESSION MATERIAL Available in 2 viscosities. Light body supplied in syringes. Heavy body supplied as tubes COMPOSITION OF LIGHT ACTIVATED POLYETHER

52. PROPERTIES OF LIGHT ACTIVATED POLY ETHER Excellent elasticity. It has operator control over the polymerization. Infinite working time. Short setting time. Low volume shrinkage on setting. Impression can be stored upto 2 weeks

53. IMPREGUM PENTA SOFT QUICK STEP HEAVY BODY/LIGHT BODY POLYETHER IMPRESSION MATERIAL FROM 3M Pentamix Mixing Unit Cartridge Dispenser Working time 1min Setting time 3min

54. POLYJEL NF POLYETHER IMPRESSION MATERIAL: Hydrophilic material with excellent memory that will not distort Optimally colored for easy to read detail Can delay pour for up to 2 weeks Adequate work time with fast set

55. AFFINITY MONOPHASE POLYETHER: It is ideal for implant impressions, edentulous, and partial impressions, as well as for the fabrication of clear aligners in orthodontic treatment. Enhanced hydrophilicity for excellent performance in the presence of moisture, especially with subgingival preparations. 100% cure, which translates to high tear strength and dimensional stability. 𝗈

56. DIGITAL IMAGING: Most of modern dentistry is already immersed in digital dentistry Computer-aided design (CAD)/computer-aided manufacturing (CAM) technologies are advancing rapidly.

57. ADVANTAGES OF INTRAORAL SCANNING: 1. Real-time visualization and evaluation Easy to correct, manipulate, or recapture images Segmental image capture Archival digitally, therefore no need to store physical casts No wastage of impression material and therefore environmentally friendly Economical, considering no use of impression trays, adhesives, or gypsum Do not need to disinfect before sending information to the laboratory

58. 𝗈 8. No damage or wear and tear of the stone casts 9. Swift communication with the laboratory via the Internet . 10. Self-assessment for tooth preparations . Increased patient satisfaction Some systems have color scanning, shade selection, and still photograph image-taking

59. DISADVANTAGES O F INTRAORAL SCANING: Initial cost of equipment and software maintenance fees Learning curve can be difficult for some individuals Scan bodies needed for implant systems that are compatible with the design software Difficult to capture occlusion information for complex prosthodontics treatment. Cannot capture subgingival margins if obscured with blood, saliva, or tissue. Unable to accurately capture images of the edentulous arches Scanning patterns need to be followed as per manufacturer’s recommendations

60. THE FOLLOWING ARE MOST COMMONLY USED SYSTEM: 1●TRIOS 3:(3 shape) An innovative wireless intraoral scanner Easy battery exchange for non-stop scanning Long-lasting rechargeable batteries Realistic colors

61. CEREC (SIRONA): This device is a closed system in that the software is only compatible with the company”s milling unit and the image files cannot be exported and used with other milling system.

62. OTHERS ARE: Planscan (planmeca,USA) CS3600(carestream, United states) Itero element(align technology)

63. REFERENCES: Anusavice,shen,rawls, Arvind shenoy, Phillip’s science of dental materials. First south Asian edition.

64. THANK YOU