denture base materials

DENTURE BASE MATERIALSIrsalan Asif

OVERVIEW

• History of the denture base material and its change over time

• Design requirements and required properties in a denture base material

• Current denture base materials in use

• Future in denture base materials

WHAT IS A DENTURE BASE

• A denture is made up of two parts; the denture base and the artificial teeth.

• A denture base is that part of a denture that makes contact with soft tissue (oral mucosa) and retains the artificial teeth

http://www.lemkedent

al.com/services_dentur

es.html

HISTORYEgyptians have practiced dentistry since 3000BC.

Since 700 BC it has been used to replace teeth.

From then on there has been a process in trying to improve the materials.

WOOD

• Wood had been used because it was readily available, inexpensive and could be carved

• Nakoka Tei used it in 1538.

• Disadvantages are that it cracked in moisture, not aesthetic, unhygienic, and degraded in the mouth.

•Tandon,Renu; Gupta,Saurabh; Agarwal, S.K. Denture Base Materials: From Past to Future. Indian Journal of Dental sciences 2010; 2(2): .

•Murray,Michael.D;Darvell,Brian.W;. The evoulution of the complete denture base. . Australian Dental Journal 1993; 3(38): .

http://museumvictoria.com.au/collections/items/259128/dental-cast-lower-jaw-plaster-circa-1973

BONE – PIERRE FAUCHARD

• Pierre Fauchard was a pioneer in dental prosthesis in 1678 – 1761.

• Fabricated the use of bone by measuring and cutting fit the mouth.

• Advantageous because of its availability, reasonable cost, better dimensional stability than wood.

• Aesthetic and hygienic concerns were not fulfilled.



PORCELAIN – ALEXIS DUCHATEAU

• Alexis Duchateau (1774) was the first to fabricate porcelain dentures

• Advantageous because it could be shaped easily, ensured close contact with the underlying tissues, stable and smooth , less porosity and low solubility

• Drawbacks were brittleness and difficulty in grinding and polishing.



RUBBER – CHARLES GOODYEAR

• Charles Goodyear,1839, discovered the process of vulcanization of rubber.

• In 1851, Goodyear used this technique to produce a highly cross-linked hard rubber named Vulcanite.

• Vulcanite bases were the first functional, durable and affordable dentures.

• Disadvantage was their dark red colour , which was difficult to pigment, and absorption of saliva making it unhygienic.



FROM 1850-1940• tortoise shell base.

• Gutta percha

• low fusing silver alloy, bismuth and antimony

• Aluminum

• Celluloid

• Bakelite

• Stainless Steel and Metal alloys: Ni-Cr and Co-Cr



PMMA

• Dr Walter Bauer invented the resin. Worked for Rohm and Haas.

• Dr. Walter Wright (1937) introduced Polymethyl methacrylate as a denture base material

• Major polymer to be used. Kulzer patented the polymerisation process and launched it as Paladon

• In 1946, 95 per cent of all denture bases were PMMA.

• Had a good stable colour corresponding to the gums, Inert and translucent, reasonably robust, inexpensive and easy to repair.

• Additional fibres can increase aesthetic characteristics

•Tandon,Renu; Gupta,Saurabh; Agarwal, S.K. Denture Base Materials: From Past to Future. Indian Journal of Dental sciences 2010; 2(2): .•Murray,Michael.D;Darvell,Brian.W;. The evoulution of the complete denture base. . Australian Dental Journal 1993; 3(38): .

DESIGN REQUIREMENTS FOR A DENTURE BASE MATERIAL

PROPERTIES

Physical

Appearance

A high Tg temperature

Good dimensional stability

Low value of specific gravity so that the denture is as light as possible.

Thermal conductivity

Mechanical

High elastic modulus/limit – rigidity

Flexural strength to resist fracture

Fatigue limit and a high fatigue life.

High Impact strength

Other

Chemically Inert so it is insoluble in oral fluids.

Non – toxic and non-irritant to the technician and the patient.

Long shelf life and cheap so that it can be bought in bulk and stored without deteriorating.

DENTURE BASE MATERIALS IN USEMetals Vs Acrylics

METALS

• Gold

• Co-Cr alloy

• Titanium

• Vitallium - alloy of 60% cobalt, 20% chromium, 5% molybdenum.

http://www.tedsakamoto

dds.com/services

• Disadvantages are that they are difficult to adjust and reline.

• More accurate than resins.

• Cleanliness of the metal base maintains healthy oral tissue unlike some resins.

• Metal alloys can be much thinner than resins and still have adequate strength and rigidity.

• Thermal conductive as temperature is transmitted through the base maintaining health of the tissue.

PLASTICS

• Acrylic

• Polystyrene

• Valpast – Flexible dentures

http://www.sanforddentalexcellence.com/ar

ticles/understanding-the-different-types-of-

dentures/

Most commonly used in denture bases.

Low TG

Low Specific GravityLow thermal conductivity

Poor Impact strength /resistance to fatigue fracture

Surface cracks can have a weakening effect on the

denture base (crazing).

Acrylic slowly absorbs water.Polycarbonates and vulcanite are used in patients

allergic to acrylic.

FUTURE OF DENTURE BASE MATERIALS

FUTURE

Ivobase

• self-curing PMMA-based materials/ Fast polymerisation

• high precision, quality and efficiency.

• Strong bond to the teeth is established.

• Safe and clean

• No skin contact with the monomer. Predosed – Ideal ratio.

•Ivoclar Vivadent. IvoBase Hybrid.

http://www.ivoclarvivadent.com/en/ivobase-hybrid (accessed 8

March 2014).

Vertex Thermosens

• Monomer-free

• Virtually no shrinkage: excellent fit

• Nylon-derived denture base material

• High creep/fatigue resistance

• High dimensional stability

• Material is light in weight, heat resistant, and ductile.

Vertex dental. Vertex Thermosens. http://www.vertex-dental.com/en/products/26-en/26/218-vertex-thermosens (accessed 8 March 2014).

SUMMARY

• Denture bases support the artificial teeth

• Denture base materials have an extensive history

• The properties required for a denture base are extensive

• Current biomaterials are metals and plastics. Two of the most common materials

• Future developments build and improve on the history of Denture base materials

REFERENCES

•Alan B. Carr, , David T. Brown. McCracken's Removable Partial Prosthodontics , 12 ed. : Mosby; 2010.

•Noort,R.V. Introduction to dental materials, 2nd ed. : Mosby; 1999.

•John F. McCabe , Angus Walls . Applied dental materials, 9 ed. : Wiley-Blackwell; 2008.

•Ivoclar Vivadent. IvoBase Hybrid. http://www.ivoclarvivadent.com/en/ivobase-hybrid (accessed 8 March

2014).

•Vertex dental. Vertex Thermosens. http://www.vertex-dental.com/en/products/26-en/26/218-vertex-

thermosens (accessed 8 March 2014).

•Tandon,Renu; Gupta,Saurabh; Agarwal, S.K. Denture Base Materials: From Past to Future. Indian Journal of

Dental sciences 2010; 2(2): .

•Murray,Michael.D;Darvell,Brian.W;. The evoulution of the complete denture base. . Australian Dental Journal

1993; 3(38): .

ANY QUESTIONS??

denture base materials

Science

denture base materialswhat

dental prosthesis

saurabh agarwal

renu gupta

use of bone

artificial teeth http

availability reasonable

better dimensional stability