This document discusses various materials used for fabricating dental dies, including their properties and uses. It covers gypsum products like dental stone (Type III and high-strength Type IV and V stones), electroformed dies using copper or silver plating, epoxy resins, and flexible die materials like polyvinyl and polyurethane. Each material has advantages like detail reproduction, strength and disadvantages like shrinkage, toxicity or incompatibility with some impression materials. Newer ceramic and CAD/CAM die materials are also introduced that are strong and dimensionally stable.
this contains the steps for the class 1 cavity preparation for amalgam in detail. also contains the difference between composite and amalgam cavity preparation.
direct filling gold... material aspect, types, condensation, cavity design, modifications. detaied seminar for post gradutes.... any doubts or suggestions contact dr.mb@hotmail.com
Anatomy and clinical significance of denture bearing areasOgundiran Temidayo
A presentation on the anatomy and clinical significance of the denture bearing areas by Ogundiran Temidayo who is a dental student at OBAFEMI AWOLOWO UNIVERSITY ILE-IFE
this contains the steps for the class 1 cavity preparation for amalgam in detail. also contains the difference between composite and amalgam cavity preparation.
direct filling gold... material aspect, types, condensation, cavity design, modifications. detaied seminar for post gradutes.... any doubts or suggestions contact dr.mb@hotmail.com
Anatomy and clinical significance of denture bearing areasOgundiran Temidayo
A presentation on the anatomy and clinical significance of the denture bearing areas by Ogundiran Temidayo who is a dental student at OBAFEMI AWOLOWO UNIVERSITY ILE-IFE
die and die materials are important in fixed partial dentures, to get the accuracy. this seminar describes die materials, its ideal requirements, and various die systems available.
dentowoman03@gmail.com
visit my youtube channel : dentowoman
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Dental Casting and Soldering Alloys.pptxDR AKANKSHA
casting alloys are defined as metals containing two or more elements in which one of the metals and all of which are mutually soluble in a molten state
Indian Dental Academy: will be one of the most relevant and exciting
training center with best faculty and flexible training programs
for dental professionals who wish to advance in their dental
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Dentistry, Periodontics and General Dentistry.
Pickling is heating the discolored casting in an acid.
The best pickling solutions for gypsum bonded investments is a 50% hydrochloric acid solution.
The hydrochloric acid aids in the removal of any residual investment, as well as of the oxide coating.
The disadvantage of hydrochloric acid is that the fumes from the acid are likely to corrode laboratory metal furnishings. In addition, these fumes are a health hazard and should be vented via a fume hood.
A solution of sulfuric acid may also be more advantageous in this respect.
Ultrasonics are also useful for cleaning the casting.
TERMINOLOGY
DESIRABLE QUALITIES
CLASSIFICATION
GYPSUM PRODUCTS
RESIN DIE MATERIALS
ELECTROFORMED DIE
AMALGAM DIE
METAL SPRAYED DIE
SILICOPHOSPHATE DIE
DIE SYSTEMS
RECENT ADVANCES
CONCLUSION
REFERENCES
gypsum is the commonly used product in dentistry for preparing study model, die and cast.
I'm Isabel uploading my slides here & will be uploading more in future. I would love if you support me on my IG: https://www.instagram.com/dentagramming/.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdfJim Jacob Roy
Cardiac conduction defects can occur due to various causes.
Atrioventricular conduction blocks ( AV blocks ) are classified into 3 types.
This document describes the acute management of AV block.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
3. Die:
It is the positive reproduction of the form of the
prepared tooth in any suitable substance.
GPT 9
A reproduction of a prepared tooth made from a
gypsum product, epoxy resin, a metal or a refractory
material.
Anusavice (11th edi)
The die is a model of the individual prepared tooth on
which the margins of the wax patterns are finished.
Schillingburg
4. BASIC REQUIREMENTS OF DIE MATERIALS
1. Reproduce an impression .
2. Dimensionally stable .
3. Setting expansion, contraction, and dimensional
variations must be minimum.
4. Strong and durable .
Robert G.Craig -Restorative dental materials- 7th edition
5. 5. Resistance to shearing forces and abrasion .
6. Compatibility with impression materials.
7. Economical
8. Easy to use
Robert G.Craig -Restorative dental materials- 7th edition
6. Non Metallic Die Material
• Gypsum Products
• Silicophosphate Cement
• Refractory Die Materials
Metallic Die Material
• Electroformed Dies
• Amalgam
• Metal Sprayed Dies
Polymeric Die Material
• Flexible Die Materials
• Epoxy Resins
Robert G.Craig -Restorative dental materials- 7th edition
7. COMPATIBILITY WITH IMPRESSION MATERIALS
Dental stone •Impression compound
•Alginate
•Zinc oxide euginol
•Agar-agar
•Rubber base material
Electro plated (copper) •Rubber base material
Electro plated ( silver) •Polysulphide
•Polyether
•Addition silicone
Polymer epoxy •Rubber base material
Resin •Polyether
•Addition silicone
•Polysulphide
8. GYPSUM PRODUCTS
Kenneth J.Anusavice -Philip’s science of dental materials- 11th edition.
Gypsum products are available in five forms (ADA Type I-
V)
Type I- Impression plaster.
Type II- Model plaster.
Type III- Dental stone.
Type IV- Dental stone with high strength.
Type V- Dental stone with high strength and high
expansion.
9. CaSO4 • 2H2O CaSO4 •½H2O +1½H2O
(Gypsum) (calcium sulphate a hemihydrate)
Gypsum is ground and subjected to temperature of 110o
to 120oC to drive off the water of crystallisation
GYPSUM PRODUCT
Calcination
reaction
In autoclave
Boil with 30% CaCl2 or MgCl2
Or
0.5 - 1% sodium succinate
Kenneth J.Anusavice -Philip’s science of dental materials- 11th edition.
10. Formula CaSO4-(1/2)H2O
Powder Shape: Uniform
Density Dense ( compared to type II)
Production Steps Heat to 100C in 30%CaCl2
solution or MgCl2.
( 100 C water or
autoclave 0.5% sodium
succinate)
12. Stone, High Strength (Type IV) (ADA No: 35)
Anusavice Phillips Science Of Dental Materials 10th Edition
13. PROPERTIES
Water: powder ratio 0.20 to 0.22 %
Setting time Initial
Final
7min
9 min
Setting expansion 0.5 to 0.7%
Compressive strength 5000 Psi
Dry hardness 92RHN
Dimensional changes 0.06%
Tensile strength 8 Mpa
14. Die Stone, High Strength, High Expansion (Type V)
ADA No: 35
15. PROPERTIES
Setting Expansion 0.10% - 0.30%.
W/P ratio 0.18 – 0.22
Setting time 12±4min
compressive strength 7000psi.
Mixing time 30sec to 1min
Working time 3 min
Temperature alters the setting time Above 50˚c retards settin
At 100˚c no reaction
16. • High-strength Type V dental stone may produce a
harder cast
• Higher degree of brittleness V.
• Type IV resin gypsum product (Resin Rock)
PROPERTIES
Schwedhelm ER, Lepe X. Fracture strength of type IV and type V die stone as a function of time. J Prosthet Dent. 1997 Dec;78(6):554-9
Fracture
17. Reproduction of detail
Gypsum dies do not reproduce surface detail as well
as electroplated or epoxy dies.
Hardness and abrasion resistance
3 times than epoxy die .
conventional type IV gypsum exhibited the highest
surface hardness
Duke P, Moore BK, Haug SP, Andres CJ. Study of the physical properties of type IV gypsum, resin-containing, and epoxy die materials. J Prosthet Dent.
2000 Apr;83(4):466-73.
18. Dimensional stability
• Liner expansion on setting V.
• Growth of the CaSO4 2H2O (dehydrate) crystals and
their impingement on one another.
• High strength stone has a setting expansion of
about 0.01% to 0.08%.
• Little change IV
Kenneth J.Anusavice -Philip’s science of dental materials- 11th edition
19. Disinfection:
• By immersing the cast in disinfectant solution like
sodium hypochlorite,glutaraldehyde.
• Incorporating disinfectant in the stone itself
• There is a significant increase in linear dimension and
significant decrease in wet compressive strength but
both the solution produced loss of surface details.
Abdullah MA. Surface detail, compressive strength, and dimensional accuracy of gypsum casts after repeated immersion in
hypochlorite solution. J Prosthet Dent. 2006 Jun;95(6):462-8
20. Advantages
• Compatible with all impression materials.
• Ability to reproduce fine detail and sharp
margins.
• Dimensionally accurate IV .
• Economic.
• Easy to use.
22. METHODS TO INCREASE ABRASIVE RESISTANCE
Substitution by colloidal silica .
• Colloidal silica: Inc resistance to surface abrasion.
• Gum Arabic
• Resin Rock
• Impregnating acrylic resin into stone die.
(compressive strength-7,000 psi)
Low viscosity resins i.e. cynoacrylate .
Hahremannezhad HH, Mohamed SE, Stewart GP, Weinberg R. Effects of cyanoacrylates on die stone. J Prosthet Dent. 1983 May;49(5):639-46
23. ELECTROPLATED DIES
• Metal dies can be made by Cu / Ag plating
• Electroplating.
• Early 1930 s
Robert G.Craig -Restorative dental materials- 7th edition
24. PROPERTIES:-
• Detailed reproduction up to 30µm.
• Have moderately high strength, adequate hardness &
excellent abrasion resistance.
- An electrolyte solution
- A source of direct current.
- An anode – pure copper
- pure silver
METALIZING
25. COPPER PLATING
• Copper plated dies – Compound or addition silicone
rubber impressions.
• 1930’s
• Surface of the impression material is treated so that
it conducts electrically. This process is referred to as
metallizing.
Composition:
• Copper sulfate
• Sulfuric acid
• Phenolsulfonic acid
Toreskog SV, Phillips RA, Schnell RI,.Properties of die materials: A comparative study ,J Prosthe Dent ,Vol 16, iss 1, Jan–Feb 1966, Pg 119-
31
26. • Surface coated with fine particles of copper or
graphite.
• The coated impression is made the cathode .
• Copper plate is anode.
• Immersed in an electrolytic solution of copper
sulphate together with alcohol or phenol.
• A current - 15 mA for 10 hours.
Notes on dental materials E.C COMBE 6TH edition
27. • Cause slow dissolution of the anode .
• Electro tuned die surface is then filled with dental
stone.
• Greater surface hardness and resistance to
abrasion than that of gypsum.
28. SILVER PLATING
• Indicated for polysulphide , polyether, and silicon
rubber impression materials.
Composition:
• Silver cyanide
• Potassium cyanide
• Potassium carbonate
• Distilled water .
Notes on dental materials E.C COMBE 6TH edition
29. • Similar to that of copper plating .
• 5 mA is sufficient.
• Coated with silver or graphite powder is made the
cathode.
• Anode is silver plate.
• The electrolyte is an alkaline solution of silver
cyanide with potassium cyanide and potassium
carborate in distilled water .
30. • Not significantly accurate than stone dies
• Continued polymerization lead to dimensional change .
• Silver cyanide solution toxic hydrocyanic acid
• Friable metal deposit if current set too high.
• Silicone difficult , because of low surface energy.
• Polyether imbibes water.
• Polysulfide silver plated but difficult to copper plate.
PROPERTIES
31. Advantages
• No expansion or contraction occur with
electroformed dies.
• Higher strength, hardness and abrasion resistance.
• Finishing and polishing of metal restoration .
• Crown margin accuracy.
Crispin BJ, Watson JF, Frawley KR. Silver-plated dies. Part II: Marginal accuracy of cast restorations. J Prosthet Dent. 1984 Jun;51(6):768-73
32. Disadvantages
• Time consuming.
• Special equipment .
• Not compatible with all impression materials.
• Expensive.
• Precaution needed.
Stevens L, Spratley MH. Accuracy of stone, epoxy and silver plate-acrylic models. Dent Mater. 1987 Apr;3(2):52-5
Stevens L, Spratley MH. Accuracy of stone, epoxy and silver plate-acrylic models. Dent Mater. 1987 Apr;3(2):52-5
33. METAL SPRAYED DIES
• Bismuth alloy with fusing point of 136ºF
is melted at 145ºF.
• Die is poured & solidify at 30 pounds of pressure.
• Advantages :
• Rapidly from elastomeric impression materials.
• Disadvantages :
• Alloy is soft, care is needed to prevent abrasion of
the die.
Toreskog SV, Phillips RA, Schnell RI,.Properties of die materials: A comparative study ,J Prosthe Dent ,Vol 16, iss 1, Jan–Feb 1966, Pg 119-
31
34. AMALGAM DIES
• Material of choice previously ,largely
replaced by electroplated dies.
• Resistant to Abrasion.
Procedure
Made by packing amalgam into impression made of
impression compound.
Advantages
• Superior strength
• Resistance to abrasion and reproduce fine details and
sharp margins.
Notes on dental materials E.C COMBE 6TH edition
36. SILICO PHOSPHATE CEMENT
Similar to the filling and cementing
material.
Composition
The powder is a mixture of silicate powder
and zinc oxide liquid contains phosphoric acid.
Notes on dental materials E.C COMBE 6TH edition
37. Advantages:
• Strength and surface hardness are superior to
stone.
Disadvantages:
• Contracts during setting
• Dimensionally inaccurate.
• Loss of water on standing .
• Presence of surface voids can occur.
Toreskog SV, Phillips RA, Schnell RI,.Properties of die materials: A comparative study ,J Prosthe Dent ,Vol 16, iss 1, Jan–Feb 1966, Pg 119-
31
38. EPOXY RESIN
• Used with polyether, polysulphide
or silicone
• Hardner polyamine causes polymerization.
• Toxic .
Composition
• Epoxy resins, polyester and Epiamines or polymeric
materials with fillers (either metallic or ceramic
fillers).
Stephen f. Rosenstiel, Contemporary Fixed Prosthodontics- 3rd edition
39. PROPERTIES
• Working time – 15 min.
• Setting time – 1 to 12 hours depending on the
product.
• Knoop hardness number is 25 KHN ±15 less than
that of high strength stone (77 KHN).
• Compressive strength after 7 days is 16,000 psi.
• Abrasion resistance is superior .
Stephen f. Rosenstiel, Contemporary Fixed Prosthodontics- 3rd edition
40. • Shrinkage during polymerization - 0.03% and 0.3% .
• Viscous when poured , porosity can occur.
• Agar and alginate materials .
• Compatible with polyether, polysulphide or silicon
impression materials.
Paquette JM, Taniguchi T, White SN. Dimensional accuracy of an epoxy resin die material using two setting methods. J Prosthet Dent. 2000
Mar;83(3):301-5
41. • Better detail reproduction, abrasion resistance, and
transverse strength than the gypsum materials.
• Retarding the setting reaction improves its accuracy .
• Detail duplication of epoxy resin dies is comparable to
that of die stone.
• Hardness values of epoxy resin are less than those of
die stone.
Philip Duke, B.K eith Moore, Steven P. Haug and Carle J. Andres Study of the physical properties of type 4 gypsum, resin-containing, and
epoxy die material J Prosthet Dent 2000;83:466-73
42. Advantages
• Abrasion resistance.
• Less brittle than die stones.
• Can be carved at room temperature.
Disadvantages
• Cannot be used with agar and alginate impression
material.
• Shrinkage on polymerization.
• Less dimensional stability.
• Expensive.
43. FLEXIBLE DIE MATERIALS:-
- Similar to heavy bodied silicone or polyether impression
material.
Use:-
- To make provisional restoration.
- Indirect composite resin inlays or onlays chairside
Advantage:-
- More rapid setting – 10min.
- Ease of removal of provisional
restoration.
44. Irreversible hydrocolloid impression
Fill with the fast setting, medium
viscosity polyvinyl impression material
Polyvinyl cast into the pre
operative mold
POLYVINYL DIE
45. The polyvinyl cast is flexed to
remove tooth colored resin from
the undercuts.
Interim restoration on the prepared
tooth
Douglass Smith, Arun Nayyar, David L. Koth - Fabrication of removable dies using cemented dowel pins J Prosthet
Dent: 1992:68:372-4
46. • Polyurethane is the most accurate,
strongest and cleanest die material
than die stone and epoxy
• silicone impression materials
• Base and hardener
Properties
• No noticeable shrinkage or expansion
• More accurate than epoxy
• Water resistant
• superior mechanical properties (94.82 MPa).
Derrien G, Sturtz G. Comparison of transverse strength and dimensional variations between die stone, die epoxy resin, and die
polyurethane resin. J Prosthet Dent. 1995 Dec;74(6):569-74
POLYURETHANE
47. Uses
• Long span bridges, inlay, onlay preparations
• excellent for scanning
• fabricating CAD/CAM models
• shoulder and partial crown preparations
48. CERAMIC DIE MATERIALS
• Recent advance in die materials.
• Porcelain inlays , onlays and veneers.
Manipulation:
• Supplied as powder and liquid system.
• Mixed into paste and vibrated into the impression
and allowed to set for an hour.
• After which the material is removed and fired at
600ºc for 8 mts to produce a strong die
Toreskog SV, Phillips RA, Schnell RI,.Properties of die materials: A comparative study ,J Prosthe Dent ,Vol 16, iss 1, Jan–Feb 1966, Pg 119-
31
49. CAD CAM
• CEREC
• The E4D (D4D TECH)
• DCS PRECIDENT SYSTEM
• iTero
• LAVA
54. DCS PRECIDENT SYSTEM
• Designed for metal
copings for PFM .
• Conventional wax up
required.
• Touch probe
• Acceptable marginal
accuracy.
55. • Concludes that manual adjustment significantly
improves the marginal accuracy of CAD/CAM
system-fabricated titanium copings.
• The highest marginal accuracy was achieved with
the DCS system, using a longer refinement time.
Witkowski S, Komine F, Gerds T. Marginal accuracy of titanium copings fabricated by casting and CAD/CAM techniques. J Prosthet Dent. 2006
Jul;96(1):47-52
56. iTero
• The iTero system uses a
camera that takes
several views (stills),
and uses a strobe effect
as well as a small probe
that touches the tooth
to give an optimal focal
length.
• NO use of powder
57. LAVA
• Chairside Oral Scanner (LAVA COS, 3M ESPE) takes a
completely different approach using a continuous
video stream of the teeth.
58. • Crowns from intraoral scans revealed significantly
better marginal fit than crowns from silicone
impressions.
• Marginal discrepancies in both groups were within
the limits of clinical acceptability.
• Crowns from intraoral scans tended to show better
interproximal contact area quality.
• Crowns from both groups performed equally well
with regard to occlusion
Syrek A, Reich G, Ranftl D, Klein C, Cerny B, Brodesser J. Clinical evaluation of all-ceramic crowns fabricated from intraoral digital impressions
based on the principle of active wavefront sampling. J Dent. 2010 Jul;38(7):553-9. doi: 10.1016/j.jdent.2010.03.015
59. ADVANTAGE
• Saves time and one visit for in-office systems
• Opportunity to view occlusion
• Accurate restorations created .
• Accurate, wear- and chip-resistant physical
CAD/CAM derived model.
• No casting/soldering errors.
• Cross-infection control.
Agrawal P, Thompson G, Cho SH, Ziebert GJ. Evaluation of die trim morphology made by CAD-CAM technology. J Prosthet Dent.
2017 Sep;118(3):406-412. doi: 10.1016/j.prosdent.2016.10.027
60. DIE HARDENER
• Materials applied on the surface to increase the
surface hardness
Die hardener:
1.Cynoacrylate resins
2.Acrylic resin lacquer
61. DIE SPACER
• Applied on the die to provide space for the luting
cements.
Die spacer:
1.Resins.
2.Paints.
3.Nail polish.
4.Thermoplastic resins.
Optimal thickness:20-40 micron
62. • Application of die spacer Exerts a favorable
influence on the SBS of composite-bonded
restoration.
• Best marginal adaptation when the die Spacer
covered all of the preparation down to 0.5 mm
short of the marginal finish line
Cho SH, Chang WG, Lim BS, Lee YK. Effect of die spacer thickness on shear bond strength of porcelain laminate veneers. J Prosthet
Dent. 2006 Mar;95(3):201-8
63. DIE SEPARATOR
• Prevent wax adhering on to the stone
• Prevent wax distort on removing.
Die separator:
1.Oils.
2.Liquid soap.
3.Detergents.
64. CONCLUSION
Good impression and die fabrication with proper
selection of the die material and its manipulation
paramount to achieve accuracy in the final
restoration.
65. REFERENCES
• Kenneth J.Anusavice -Philip’s science of dental materials- 11th
edition.
• Robert G.Craig -Restorative dental materials- 11th edition.
• William J.O’Brien -Dental materials and their selection- 3rd
edition.
• Stephen f. Rosenstiel, Contemporary Fixed Prosthodontics- 3rd
edition.
• Herbet T. Shillingburg - Fundamentals of fixed prosthodontics
third edition.
• Notes on dental materials E.C COMBE 6TH edition
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shear bond strength of porcelain laminate veneers. J Prosthet Dent.
2006 Mar;95(3):201-8
68. • Agrawal P, Thompson G, Cho SH, Ziebert GJ. Evaluation of die trim morphology
made by CAD-CAM technology .J Prosthet Dent. 2017 Sep;118(3):406-412. doi:
10.1016/j.prosdent.2016.10.027
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evaluation of all-ceramic crowns fabricated from intraoral digital
impressions based on the principle of active wavefront sampling. J Dent.
2010 Jul;38(7):553-9. doi: 10.1016/j.jdent.2010.03.015