Case Study: You know the drill...
Critical plastic parts made and supplied by Proto Labs’ rapid injection moulding service have helped to accelerate the time-to market of a new, drill-less dental treatment. The innovative system, developed by DMG Dental, means that a trip to the dentist, dreaded by many, could soon be a less fearful and much quieter experience.
For many people, the high-pitched whir of a dentist’s drill is sufficiently chilling that they would prefer to take chances with their oral hygiene than book an appointment for a routine check-up. A brand-new device created by DMG Dental may just convince them otherwise.
While most people brush their teeth as part of a daily routine, flossing, for many is an occasional practice at best. However, the rather unpleasant truth is that the spaces between the teeth offer the perfect environment for the acid excretion of bacteria that attacks tooth enamel minerals. This leads to the development of ‘pores’ in the tooth surface that subsequently give way to decay.
Until now, the only way to treat decay between the teeth was by drilling to reach the cavity and allow filling – an approach that almost always leads to the loss of a substantial amount of perfectly healthy tooth. However, DMG Dental, with its award-winning new Icon system achieves the same result without the use of a drill. The success of this product is based upon the application of plastic inter-dental wedges to separate teeth that are very close-set.
"It is essential that the dentist has enough space between teeth to complete the entire treatment,” says Herr Steffen Effenberger, head of technical development at DMG. "Dentists were already using wedges in other procedures, but they were usually made of wood. We couldn’t use wood since it would absorb the materials used in the treatment after tooth separation, so we started the development of an appropriate plastic wedge". In essence, DMG had to re-invent the inter-dental wooden wedge.
"The challenge was to realise a universal standard wedge that could separate all types of teeth adequately,” says Herr Effenberger. “We started by changing the geometry, creating a trapezoidal shape in cross section. Initially we used our own 3D printer to create about 10 different prototypes.
However, for the field tests these were unsuitable because they have very different material properties. Tooling would generate additional costs, which for a non-field-proven product was too risky. Not to mention, it would take too long. Then, a colleague discovered another option at a trade show: the rapid injection moulding service from Proto Labs®. All we needed to do was upload our 3D CAD model to the Proto Labs website and within a day we had an actual production quote in our hand.
The team at DMG was more than surprised by the speed and reliability it experienced with Proto Labs’ service. Previously, the company had been forced to accept prototyping lead-times of more than 8 weeks. But, this was reduced with Proto Labs down to 2-3 weeks from initial contact to receiving finished parts.
“In fact Proto Labs would have been even faster, but we still had to clarify a few things,” explains Herr Effenberger. “For instance, we needed to provide our own material to Proto Labs so we could meet particular medical standards. From then, development accelerated rapidly – we were chasing responses from dentists so we could improve our inter-dental wedge. For example, we discovered the ‘comb’ could be omitted entirely, while an arch in the lower part of the wedge made it even more resistant to distortion and provided an optimal fit to gum pockets.”
After only four weeks of development, the current version was completed at the end of August 2011. The first deliveries have been made with initial, low volume production batches supplied by Proto Labs while DMG waited for the manufacture of steel tooling for full-scale mass production.
“Our existing tool supplier was glad that we had worked with Proto Labs during the prototype stage because they are not set up for frequent modifications or low volume production,” says Mr Effenberger. “Simply, we wouldn’t have got to market so quickly without Proto Labs."
So how does Icon work? Well, once the inter-dental wedge has separated the teeth, the surface of the unhealthy tooth can be pre-treated with a special gel. The area is then dried with alcohol before the Icon resin is applied using a plastic syringe to penetrate the decay, seal the pores and harden.
"We have found a partner in Proto Labs, who provides high reliability in order processing,” concludes Herr Effenberger. “Every deadline was met! In fact, often, the promised 24 hours from uploading the 3D model was much reduced and the manufacturability advice that we received for the realisation of our models was very good. For this reason, we have used the injection moulding process for improvements to our syringe applicator. Whenever time is short and we need real parts, we rely on Proto Labs as a partner to develop products faster and better.”