One of them is the COSHH which is a legal framework to protect people from any hazardous substances used at work .This is very important to insure people s safely which is why all substances used have a risk assessment and also all labeled carefully explaining any hazards i.e. Toxic, Harmful, Biohazard.
Use of correct equipment is a must
Eye protection to protect any flying objects and substances or particles getting into eyes.
Gloves to protect Harmful substances affecting your skin.
PPE …Laboratory coat for protection.
Disposing of any clinical waste should be put away in an environmentally safe way.
Impression review and the application of special treatment needs
A dental impression may be described as an accurate
Representation of a person’s dentition and other areas of the mouth.
On receipt of the impression it is necessary to
Disinfect.
Check the impression for air blows in areas to be worked upon.
Distortion of the impression.
If the alginate or silicon is set adequately for casting.
use debubblizer for the silicone impressions
Rinse the alginates.
Standard operating procedures
It is important to follow procedures. In a correct and efficient manner. Medical Devices Directive (MDD) The requirements for individuals workers to follow procedures in the dental laboratory .
Please refer to appendices A.
Quality assurance procedures.
All dental technicians will have a registration number from the general dental council to show they are working at a level of responsibility and competence.
The Mdd (medical devices directive) requirements are too make sure any information is received in the correct manner and recorded of work in and out for clients via dentist . Procedures must be followed for the legal contracts of employments and confidentiality and employers regulations records and
Protocols used within the dental laboratory to meet this directive.
Legal requirements relating to a third party insurance is paramount
The coshh which is the stages of risk assessment and the health and safety at work act 1974 and eviromental protection act also must be followed,
All equipment used must met laboratory requirements and been tested, and use quality assured Products on cases.
How to progress the case (s) from receipt
Check the prescription (which is a form of contract) for all relevant information needed.
Identify materials and equipment to be used are in good working safe order
Risk assesment
Disinfect all impressions to avoid cross contamination
Use PPE
Check impressions for any increpencys
Report any problems immediately
Part 2
Manufacture of the casts and dies for the production of a single fixed metallic prosthodontics restoration.
Pin dex system
Disinfect impression.
Rinse impression.
use debubblizer if silicone impression.
use die stone and mix according to packet instructions for the required amount needed.
place mix in vacuum pot and vacuum for approx 1minute.
Gently poor insuring all area don’t have air pocket using the vibrating machine and margins are correctly covered.
pour from molar teeth round to molar teeth.
pour die stone into the tray.
turn cast impression over once in a semi set stage and align impression correctly over tray and trim back any excess mix.
Allow cast to set then remove impression and check the cast is a correct replica and the margins are in form to allow a restoration to be made.
check for any voids , and visible defects .
carefully remove from tray by tapping the center and sides.
Saw the model where the segment needed is.
Use a tooth brush and clean tray and cast model taking any cast dust from sawing away to allow model to fit neatly in tray.
poor opposing models in kaffe D and base and trim.
tray sytem
Rinse impression
Disinfect impression
use debubbizler if silicone impression
use Die stone and mix according to packet instructions for the required amount needed
place mix in vacuum pot and vacuum for approx 1minute
Gently poor insuring all area don’t have air pocket using the vibrating machine. and margins are correctly covered
Base model making sure posterior teeth have heels.
Once model is set remove impression from the model carefully checking for any defects.
Trim base and side and lingual side of model.
Cut out the lingual part of the model
Using the pindex machine start to drill holes as determined by the number of segments the die stone model will be cut into.
Start to put pin in the holes with a small amount of glue and place the sleeves over the pins.
Base models in a tray
Once set trim round model and bottom allowing the pins to be on show
Gently saw the model each side on the unit that is needed to be worked upon.
Research and review of cast and die manufacturing systems.
There are many different types of refectory die systems and dental laboratories will chose different one depending on the prices , durability , accuracy of the die system and convience.
Here are three I investigated.
Zeiser model – it is probably the most accurate of all crown models. It will eliminate the double expansion which you can get when using the saw cut systems as the dowel pins are mostly pushed apart by the linear expansion of the die stone and plaster base. A minimal amount of plaster is used with this product.
Pictures by Melanie Butler
Pindex model system – the pindex system gets it name from the pindex drill. The pindex drill puts hole in the base of the model of similar size and length .the advantages of the pindex system is it gives very good stability of the die. It is very presentable. You are not using the same trays repeatedly so therefore the tray will not come back in used condition and used again making the appearance not very good.
Tray systems
This system is quite quick to prepare a model cast, no pins are required. just plaster and sawing is needed for this appliance . The die tray allows the technician to remove the working model from the tray, separate the individual tooth or teeth to be worked on and return the working model (often in several pieces by this time) to the die tray, The use of a central die retaining tongue gives a positive lock for the dies after sectioning without putting any physical barrier between the technician and the margins so that a full view of the buccal margins is maintained. Orange casting tongues are supplied to accommodate expansion of die stone and white working tongues for use in securely retaining model segments in the Model Tray. The tongue removing tool makes the tongue easy to remove.
I asked a laboratory owner Mr. Williams from jw dental ceramics his opinion on these systems and was told from him that he used to use the tray system but now uses the pindex model system as it is more accurate and looks more pleasant than the trays do after a month or so of reusing the same trays over again and worked out more cost affective in the long run for his business as they do not always get the tray returned from the dentists. On reflection on changing the product used Mr. Williams found the cost was not that different between the two as pindex + plaster + labor s equivalent to tray cost but presentation is far better.
I phoned several companies to find out the cost of these item and they all roughly cost between 80p to £1.00 per tray or pins and plaster cost .
Review of articulation techniques available for use in conservation technology.
Articulator is used because it simulates jaw movements.
Articulation for the majority of crown and bridge are generally used by hand method of using the opposing model in place to check the occlusion surface room of the crown
It is necessary to have this method to determine proper size, fit and movement of the fixed metallic restoration relative to the other teeth of the patient.
There are a few types of articulators used in the dental laboratories
The very basic is a simple method of gluing both the upper and lower to this simple
Articulator is one option.
Picture by Melanie Butler
The more advanced choices are the type an articulator which is semi adjustable.
An articulator represents the temporalmadibular joint and jaw which the lower and upper cast can be attached to simulate an actual persons jaw.
Picture by Melanie Butler
It can be changed by adjustment of the condoyle –fossa part of the articulator the represent the forward and backward motion of the jaw.
Critical analysis and self reflection.
I made two different types of cast model one using the tray system and one using the pindex system.
I struggles a lot with the tray system the fault s I found were after pouring the die stone and allowing to set the cast impression was very hard to take out of the tray after repeatedly taping for long time it eventually did come out of the tray and I did apply some separation spray to the tray beforehand ,
When I had to saw the model into segments I found that after I had sawed the model did not fit correctly into the tray even after cleaning the tray and model free from dust collected from sawing.
I had to use the hand tool and grind away some of the jagged edges left after sawing to enable the model to fit back into the tray which then left a little bit of instability with the model having more movement than it should have.
It is possible that I had lots of fault with this due to my inability in sawing straight.
I didn’t have any problem with the pindex system I found it a very easy process to follow and my model looked very presentable and was in very good working order. The segments that were sawed fitted back into the model accurately and didn’t need any other kind of trimming or cleaning to make it fit on and off the model easily.
References
Bracon.co.ukb/catalogue_categories_equipment.php.
DEEPAK NALLASWAMY (2003) textbook of prosthodontics. Jaypee, Brothers medical publishers’ ltd.
J.R CLARK.et al. (June 2001) Functional Occlusion: II. The Role of Articulators in Orthodontics. Journal of orthodontics, vol28...(no2.), (173-177).
Assess the feasibility of meeting client requirements for custom-made dental devices.
Appencies A.
DT01.1 Prepare and maintain environments, materials and equipment for reviewing client contracts
The worker will need to:
review the prescription and contract and correctly identify the materials and equipment which will be required
assess correctly the risks to the worker and others involved in undertaking the design and manufacture of the custom-made dental device
use working methods and systems throughout the process which:
promote health and safety
reduce the risk of infection and contamination
are consistent with the assessed risks
confirm that the environment in which the work is to be undertaken is in a fit state ready for use and if it is not, take any necessary remedial action
use suitable personal protective equipment and take the necessary precautions
select the correct type and quantity of materials that will be required
confirm that the required equipment is:
clean
in working order
set correctly
report to the appropriate person as soon as is possible any problems with equipment and materials
move and handle equipment and materials in an appropriate, safe manner which is consistent with current legal and organisational requirements
dispose of waste in a suitable container and in an environmentally safe manner.
Range
Materials and equipment for:
disinfecting impressions
preparing casts.
Problems:
with equipment
with materials and supplies
with the information supplied by the client.
Explanatory note
The 'preparation of the environment' in performance criterion 2 will include ventilating the area appropriately (eg through using extraction systems for fumes and dust) and adjusting the lighting.
DT01.2 Determine client requirements for custom-made dental devices
The worker will need to:
record requests and specifications for custom-made dental devices:
as soon as they are received
accurately and completely in the appropriate documentation
in a manner which is consistent with legal and organisational requirements
disinfect the impression before it is evaluated for its suitability
assess the information received from the client for its clarity, and make clear and accurate records of:
patient identity, age and gender
prescribing client's identity
reason for the device
type of device required
components required
timescale for progress and completion
requirements for specific materials
any other specific requirements of the client
radiographs and photographs if these are required
assess the quality of the impression and occlusal registration for their ability to form the basis of accurate casts
assess the technical feasibility of the client's prescription
determine a laboratory route that is capable of meeting the prescription
contact clients promptly and politely using agreed procedures when:
there is insufficient information to accurately identify what is required
the impression and occlusal registration are of poor quality
there are concerns as to the technical feasibility of the prescription
discuss issues with the client in ways that promote effective working relationships, reach agreement with them on how to proceed and record the agreed changes and cost.
Range
Impression and occlusal registration relating to:
dentate upper jaw
edentulous upper jaw
partially dentate upper jaw
dentate lower jaw
edentulous lower jaw
partially dentate lower jaw
deciduous dentition.
Explanatory notes
In performance criterion 3, ‘any other specific requirements of the client' would include costs.
In performance criterion 7, poor quality impression may relate to: insufficient coverage and depth, insufficient detail, impression distortion, use of inappropriate impression materials, or adhesion of the impression to the impression tray.
by
kaka12 (student)
