Saturday, February 27, 2016

Special materials trays - composition and characteristics

Having worked with both autopolymerizing and light cure special tray material, what is the composition of each and name the characteristics of each. Each student to post at least one comment on each material.

13 comments:

  1. Light cure:The basic composition of Cavex LC Dental Tray is 5 – 10 % high molecular acrylates with inorganic fillers and pigment.
    ¤In comparison with other special
    tray materials, it is remarkably easy to use.
    ¤It has an indefinite working time.
    ¤It is non-sticky and easy to adapt.
    ¤It does not slump.

    Autopolymerizing:

    Powder
    Polymer - poly (methyl methacrylate)
    - benzoyl peroxide initiator
    0.2-0.5%
    - pigment, about 1% ground
    into poloymer particles.

    Liquid
    Monomer - methyl methacrylate
    - 0.006% hydroquinone -
    inhibitor
    - Activator - dimethyl-p-
    toluidene
    ¤¤It has a limited working time before it starts to heat up and sets.
    ¤It is sticky and very easy to adapt.
    ¤It has the tendency to slump if the material has not set.

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  2. The Autopolymerizing special tray material has two parts to it which is the powder and liquid. The powder being a polymer consisting of Benzoyl peroxide initiator, methyl methacrylate and pigment ground into polymer particles. The liquid is the monomer which is methyl methacrylate, a small portion of hydroquinone initiator and Dimenthyl-p-toluidene. Some of the properties of this material is that it tends to stick to surfaces therefore when using it be sure to apply vaseline. It also has a set amount of time before it starts to set so be sure to work at a constant speed.
    Therefore we can define this material as one which is able to be polymerized by chemical catalysis as seen above rather than by the application of heat or light in order to repair dentures or for complete dental restoration as well as for impression trays.
    The light cure material consists of high molecular acrylates with inorganic fillers and pigment. It is used to fabricate customized trays for fixed and removable implant-restorations. In addition it also helps with forming a stable base for a bite registration and wax try-ins. Not to mention, Light Cure prevents possible problems such as a lower bond strength.
    Properties include it being mouldable, fast and easy to work with, accurate adaptations and it stablizes the shape immediately after polymerization.
    http://www.slideshare.net/indiandentalacademy/autopolymerizing-acrylic-resin
    http://www.ivoclarvivadent.com/en/products/removable-denture-prosthetics/auxiliary-materials-for-dentures/light-tray

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  4. Autopolymerising resin is seem to be the most difficult special tray material to work with, because of it's working time being extremely short. The autopolymerising resin is in powder form namely polymethylmethacrylate. The light cured special tray resin is the type of special tray resin which is preferable because of it's working time because it will not set until you put it in a light curing camber and adequate strength when it sets. It is composed of matrix of urethane dimethacrylate.

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  5. Autopolymerising resin is seem to be the most difficult special tray material to work with, because of it's working time being extremely short. The autopolymerising resin is in powder form namely polymethylmethacrylate. The light cured special tray resin is the type of special tray resin which is preferable because of it's working time because it will not set until you put it in a light curing camber and adequate strength when it sets. It is composed of matrix of urethane dimethacrylate.

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  6. Light cured special tray resin:
    Matrix of urethane dimethacrylate
    Acrylic polymer
    Microfine silica fillers

    Autopolymerising resin:
    Powder- polymethylmethacrylate
    Initiator- Benzoyl peroxide
    Pigments- salts of Cadmium/Organic dyes
    Liquid- Methlymethacrylate
    Activator- N,N-dimethyl-p-toluidine

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  7. Autopolymerising resin:
    -composition:
    -Powder (polymer) polymethylmethacrylate
    -initiator is a peroxide such as benzoyl peroxide
    -pigments such as organic dyes or salts of cadmium.

    -Liquid (monomer)methyl met have to are
    -activator N,N-dimethyl-p-toluidine

    -Properties:
    - limited working time before material sets
    - flexible
    -easy to adapt on model

    Light cure material:
    -composition:
    -matrix of urethane dimethacrylate
    -acrylic polymer
    -microfine silica fillers

    -properties:
    -easy to adapt on impression
    -easy to use

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  8. Autopolymerising resin:
    A putty-like substance is formed when polymethylmethacrylate powder (a polymer) is mixed with a liquid methylmethacrylate (a monomer).
    It becomes less sticky and more like dough as time passes - when the material is like this, it's the ideal time to work it.

    Hereafter it will become very hot and progressively rigid as it sets; thus unworkable.
    The monomer has a sharp, distinct smell should be kept in monomer-resistant containers: usually made from silicone or glass, because it would react with normal plastic-based containers.
    I personally found it appealing to work with this material, due to its malleability and that one could add more material to an already-set piece or tray, but the bulk of trimming and shaping it to a consistent shape is time consuming.

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    Replies
    1. I also agree with and reference the above comment by nabeela cassiem for the specifics of composition and properties of autopolymerising resin.

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  9. Light cure special tray resin:
    I reference the above comment by nabeela cassiem for the specifics of composition and properties of light cure resin.

    Compared with the autopolymerising resin,this material was much easier to work with for various reasons, including:
    * The material comes in a sheet of a consistent thickness and size, which means general shaping should not be needed.
    *The working time is much longer than with autopolymerisation resin and cures only when exposed to light (specifically UV light).
    *It does not warp or shrink during its curing stage.

    Even with these advantages, it is difficult to modify a light cure special model with more resin after the tray has set to a satisfactory level.
    I also accidentally dropped a finished special tray I made from this material and it broke very easily; this wasn't the case with a tray made from autopolymerisation resin (also dropped accidentally...).

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  10. Light cured special tray resin:

    Composition- mateix of urethane dimethacrylate, acrylic polymer and Microfine silica fillers.

    Characteristics- Easy to use, resistant to water resorption, the quality is consistant, reduced shrinkage of polymerisation and excellent dimentional stability.

    Autopolymerising resin:

    Composition- polymethylmethacrylate (powder), Methylmethacrylate (liquid),initiator (peroxide), pigments (salts of cadmmium/organic dyes),activator (N,N-dimethyl-p-toluidine).
    Characteristics- short working time, easy to adapt but can loose the required thickness and shape if the material slumps. To prevent this, keep placing the material in place and maintain the thickness until the material starts to set.

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  11. Light cure impression material:
    Composed of: matrix of urethane dimathacrylate, microfine silica fillers and acrylic polymer

    Properties: very easy to use and takes time to set so you have more time to work with it

    Autopolymerising impression material.
    Composition:
    Powder
    - polymethylmethacrylate
    - benzolyl peroxide
    - salts of candmium

    Liquid
    - methylmethacrylate
    - activator: N,N-dimethyl-p-toluidine

    Properties
    - sets quite quickly so you have limited working time
    - sticky
    - easy to adapt to impression

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