DENTAL TECHNOLOGY
CLARKE TWIN BLOCK
CONSTRUCTION TECHNIQUE By David Baldry I Atomic Dental Lab The following detailed procedure is the technique that I use to manufacture Clarke Twin Block appliances in the most efficient way possible, whilst maintaining consistency and quality. Some steps that are obvious or not adding value have been skipped.
l Follow the prescription for construction of the retention components. In this case its Adams cribs on the upper and lower 6’s & 4’s with ball ended clasps on the lower anteriors. Wax the components into place and wax out the interdental wires so that the cribs can be adjusted by the clinician if required.
l To manufacture a Twin Block appliance, a prescription, upper & lower impressions and protrusive bite are required. The procedure starts after the Lab infection control measures have been followed and after the models have been cast, passed QC and articulated.
l Remove the wax bite and if the bite is excessively open or closed, then adjust the articulator so the space between the posterior teeth is approximately 4-5mm.
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l Using a sheet of pink wax, create angled shuttering and attach to the lower model. The posterior angle of the wax should be approximately 60 degrees (although the prescription for this case says 45 degrees!). Line the posterior section of the wax with the mesial interdental wire of the crib on the 6’s (this will make trimming easier at a later stage). Extend the wax so this it is extends just higher than the tips of the teeth on the opposing model.
l Block out the undercut areas of the wax support and repeat for the other side.
www.dentaltechnician.org.uk 07/12/2021 19:33
