Mandibular advancement splints are

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1 Silensor appliance: Construction and theory - Part 1 By Peter Herring, Adv Dip Dent Tech, ACCDP Mandibular advancement splints are now a well-established treatment for snoring and obstructive sleep apnea and consequently, many studies have been made with these appliances (including the Silensor device) to verify their efficacy. The orthodontic department of the Eberhard Karls University in Tübingen asked Dr Andreas Mauch to write a doctorate title on subject. This involved making a comparison of all the studies he found with the result that the effectiveness against snoring is always the same with these appliances and shows some success with 82% of the patients. With regard to the obstructive sleep apnea, there has been an average reduction of the AHI index of about 54%. Two studies with the SILENSOR show similar results: The study of Dr Peter L. Estrange has been made with 29 patients that suffer from a moderate obstructive apnea until an index of 20. The result has been that wearing an MAS, all the patients had an index of max. 8 and the conclusion has been that the cases of moderate obstructive apnea can be treated with mandibular advancement splints. Figure 1. An excellent compromise to achieve great comfort and sufficient retention. Figure 2. Mouth closed, respiratory tract open. Figure 3. Mouth open, respiratory tract more open. Figure 4. For the fabrication of a Silensor out of Erkodur (hard type), the marking of the prosthetic equator is recommended and the desirable undercuts engaged with Erkoloc-pro material unless attention is needed to this. Figure 5. Block unwanted undercuts and spaces with Erkogum, relieve tension from the gingival margin with Erkoskin. Figure 6. Determine the appropriate measuring template to use (see following diagrams) and hold in situ with Erkogum and mark the position of the spacers with pencil. 62 elaborate September/October 2009

2 Clinical Research Associates (CRA) has tested the effectiveness of the Silensor (Silent Nite) on primary snoring with 13 patients. Result: effectiveness against snoring 95% with the device recommended by 92% of the testing dentists. However, there has been a great difference between the various constructions in regard to their acceptance among patients and as with CPAP and other modalities, comfort and compliance are closely linked. With this regard Silensor has the advantage of being one of the least intrusive devices available. Figure 7. With the preliminary preparation and positioning setup complete we can now proceed to the completion of the Silensor appliance in Part 2. About the author Peter Herring is a dental technician and prosthetist based in Perth, WA. He is a regular contributor to elabo- RATE on thermoforming and is the Australian agent for Erkodent thermoforming machines. He also runs a busy laboratory dedicated to thermoformed appliances. For info, call or pjh@erkodent.com.au September/October 2009 elaborate 63

3 Silensor appliance: Construction and theory - Part 2 By Peter Herring, Adv Dip Dent Tech, ACCDP Because it is a completely thermoformed appliance, construction of the Silensor is relatively simple and time efficient. The bases can be made in a range of materials - from softer EVA s, dual laminates (preferred) and hard materials. Choice of equipment, however, plays a large role in the success of the final case. Rapid vacuum machines are most suitable for the majority of cases where available retention is sufficient; pressure thermoforming units are used if undercuts for retention are minimal. Older basic vacuum machines will not provide sufficient adaptation to form the bases correctly. Figures 1-3. Following on from Figure 6 in the previous article (Sep/Oct 2009), put a viscous drop of plaster onto the marked points. Isolate the measuring template with vaseline and press into the plaster; Remove excessive plaster and allow to set; Glue the spacers with quick-acting adhesive onto the spots imprinted in the plaster. Figures 4-6. Mark the front surface of the spacers with a felt pen; Embed the model in a way that in the area of the spacers 10 mm remains visible and in the other areas 2-3 mm; and then compress the granules. Figures 7-9. Thermoform and remove from the thermoforming unit when completely cool. For easier removal of foil cut radially with the fissure bur; and then take off the model and cut out roughly; Cut to the final form with a HSS twist drill (without pressure, >20,000rpm) leave sufficient material around the hinge joints. 56 elaborate November/December 2009

4 Figures Chamfer the edges with the crosscut tungsten carbide bur (>20,000 rpm); Then carefully grind the foil at the front surface of the spacers (tungsten carbide bur) until the colour is just abraded - not more and not less! Then press the spacers out towards the inside; Now or after the next step remove the isolating foil (if applicable); and smooth the borders and the other areas with a LISKO-S disc (10,000rpm). Figure 14. SILENSOR out of ERKODUR material (Hard) and Figure 15. SILENSOR out of ERKOLOC-PRO (Dual laminate). The extension of the SILENSOR out of ERKODUR or out of ERKOLOC-PRO only differs in the front. In case of the SILENSOR out of ERKODUR the vestibular area of the upper front remains free to avoid parodontal pain. The splints only cover the gingiva where the hinge joints require this. Figure 16. The correct placement of the connectors, especially the secure clicking-in of the stopper according to the drawing is extremely important! About the author Peter Herring is a dental technician and prosthetist based in Perth, WA. He is a regular contributor to elabo- RATE on thermoforming and is the Australian agent for Erkodent thermoforming machines. He also runs a busy laboratory dedicated to thermoformed appliances. For info, call or pjh@erkodent.com.au Figure 17. Take shells, connectors and stoppers from the card. Put the shell instead of the spacer. Figure 20. Stopper correctly clicked into place. Figure 18. Put the connector over the standing out part of the shell... Figure 21. Completed Silensor appliance (from ERKOLOC-pro). Figure and press the stopper into the shell until you hear it click!!! If necessary use SILENSOR pliers. The appliance is now ready for insertion. In the next article (Part 3) we will discuss insertion and removal, special cases and care of the appliance and as this is the last issue of elaborate for 2009 we would take the opportunity to wish a Merry Christmas and prosperous New Year from all at ERKODENT Australia. November/December 2009 elaborate 57

5 Silensor appliance: Construction and theory - Part 3 By Peter Herring, Adv Dip Dent Tech, ACCDP In this final article, we will discuss techniques to deal with compromised dentitions, patient instructions and maintenance regimes for the successful delivery of the finished appliance. Fabrication on compromised dentitions Although a complete dental arch is optimal for support of the Silensor appliance, it is still possible to successfully construct the appliance on compromised dentitions. The techniques for this are illustrated in Figures 1 and 2, however discretion should be used (particularly in the case of free end saddles) to ensure sufficient retention and stability remains for the finished case. Patient insertion and removal Snoring appliances, by necessity, must have a high degree of retention. This can lead to difficulties for insertion and removal with some patients if instructions for this are not followed. Patients are best instructed to insert and remove the Silensor as shown in Figures 3-6. The appliance should never be removed by pulling on the hinged components. The patient should be capable of demonstrating this procedure before leaving the surgery. Instructions for cleaning and maintenance The appliance should be cleaned and maintained as follows: Figures 1a-b. A missing molar can be replaced with a plaster rim upon which the spacer is placed, shown here pre thermoforming and the finished result. Cleaning agents: Soap, liquid soap and dishwashers - Do not use any strongly perfumed soaps. Do not use toothpaste (as it contains abrasive particles); mouthwash (as it can cause discolouring); or water that is hotter than 50 C (or deformation can result). Cleaning agents for dentures can be used for bases constructed from Erkodur but do not have any advantage. They are generally not suitable for appliances constructed from Erkoloc-pro. Figure 2a-b. A free end situation can also be managed with a plaster rim as shown, This should extend to the estimated position of the first molar. After use: Wash well with water. It is best to thoroughly clean the inner and exterior side of the splint with a toothbrush and soap; Again wash well with water; Shake off the water or dry with a towel; Never use hair driers as deformation will result!; Very important: Allow the splint to completely dry! Keep it in a dry place; and Wash with water again before use. 54 elaborate January/February 2010

6 Figures 3-4. Insertion: Seat the lower base completely and the seat the upper base - do not attempt to bite the appliance into position. Figures 5-6. Removal: The reverse of insertion, remove the upper base downwards and then ease the lower base upwards. Generation of bad smells If, after some time, the splint has adopted a strong smell, in addition to the above instructions, put the splint in a non-perfumed, concentrated soap solution for one hour. Following this, wash thoroughly with water. This process will remove most of the smell-generating bacteria. Discolouring Soft thermoforming materials have the tendency to discolour. This intake of colour pigments can be reduced or avoided by a careful maintenance but it cannot be reversed. Mouthwashes and amalgam fillings can also cause discolouring. Disinfection and sterilization The appliance can be disinfected with commercial alcohol-free disinfectants. If Erkoloc-pro has contact with alcohol, it must be stored for approximately 5 hours in a dry place without any pressure on it in order to ensure that the alcohol can evaporate completely. Otherwise the bonding of the hard and soft layers cannot be guaranteed. Sterilization with gas and plasma (<50 C) is possible. The thermoformed materials are not autoclavable. About the author Peter Herring is a dental technician and prosthetist based in Perth, WA. He is a regular contributor to elaborate on thermoforming and is the Australian agent for Erkodent thermoforming machines. He also runs a busy laboratory dedicated to thermoformed appliances. For info, call or pjh@erkodent.com.au January/February 2010 elaborate 55