In a Dental Review exclusive we profile Swift Dental Group’s transition from Bronze Age to digital dental manufacturing, aided by Renishaw
The Artemision Bronze is an ancient Greek sculpture recovered from the sea off Cape Artemision, hence its name. It represents either Zeus or Poseidon and is slightly over life-size. Despite the uncertainty about who the statue represents, it is known that it was made using a process called lost-wax casting.
Lost-wax casting is still used today and the process hasn't changed much since the famous bronze was manufactured by ancient Greeks nearly two and a half thousand years ago, and it was a venerable process even then. Commonly used in jewellery making, it is also popular in dentistry. Albeit lost-wax is a time-honoured process, Bolton-based Swift Dental Group recently sourced a faster, more accurate and efficient method to use at its laboratory – thanks to the help of global engineering and scientific technologies company, Renishaw.
Established in 1984 by Roy McGillivary and Mark Stevenson, Swift Dental Group began life as a small, family-run business. Over the last 30 years, the company has grown to become one of the UK's leading dental laboratories, with an onsite teaching and training facility, fully equipped dental surgery, and its seminar and conference facility.
Swift manufactures implants, crowns and bridges, prosthetics, chrome work and orthodontics for dental surgeries right across the UK. Before working with Renishaw, Swift was using the ancient art of lost-wax casting to create its metal frameworks, a time expensive procedure.
As the company’s volume of work increased the team started to consider the potential of digital design and manufacturing to increase its production efficiency while maintaining accuracy. Business development manager Paul Perkins was tasked with investigating potential manufacturing solutions.
"Before meeting Renishaw, Swift began working with a German company to try and develop a digital manufacturing process that was completely new to the dental industry. We sent designs and prototypes back and forth, but soon realised that we needed to take a different approach."
Mirrored production line
That different approach meant talking to Renishaw. Castings need to be extremely accurate in the dental industry — the tolerance limits of a dental casting are approximately half the thickness of a human hair. Achieving this level of accuracy with lost-wax casting can be difficult and too often frameworks needed to be reworked after being sent to the dentist and tried in the patient’s mouth, which is a far from ideal situation leading to wasted time and patient recalls, it was time for Swift to consider a twenty-first century solution.
Thanks to developing a developmental partnership with Renishaw, Swift replaced lost-was with additive manufacturing in its production process – which fitted seamlessly into the lab’s newly implemented digital workflow. Renishaw supplied an AM250 system, which uses a high-powered ytterbium fibre laser to fuse fine metallic powders together to create a final three-dimensional structure.
The AM250 is coupled with Renishaw's DS30 precision blue light scanner, which creates a digital copy of a dental impression or model. The dental frameworks are virtually designed in Renishaw Dental Studio (RDS) and exported as 3D CAD data. These digital files are then sent to the AM250 and the finished prosthetics are printed from 40 micron layers of CE-marked cobalt chrome powder. Up to 300 dental frameworks – each with a unique ID tag – can be printed in as little as eight- to twelve-hours.
During the first two weeks of production, Renishaw mirrored Swift’s production line at its site in Gloucestershire, giving the laboratory confidence that, if there were any initial problems with the system, back-up products would be instantly available.
"The fact that Renishaw offered us the mirrored production line during set-up gave us the assurance that there would be no loss of production or downtime during the initial machinery changeover," explained Perkins.
"The installation process was managed excellently by Renishaw, which enabled a smooth transition for our staff. The machine was delivered in mid-February and, within two weeks, we were up and running. Our staff embraced the digitalisation of the process and it gave our younger members of staff the chance to showcase their skills."
Award winning laboratory
In 2016, Swift Dental Laboratory won the Laboratory Award’s categories; Best Dental Laboratory and Best Digital Dental Laboratory. The nationwide award scheme aims to recognise and reward outstanding work carried out by laboratories in the UK. Perkins directly attributes the award win to the successful implementation of Renishaw's technology.
"Renishaw's manufacturing expertise is one of the best kept secrets in the UK," continued Perkins. "Not only is the company's technology on the cutting edge of the global manufacturing industry, but its technical support and customer service is first class.
"In-house laboratory processes are much smoother and more efficient than ever before, and the level of accuracy we are able to achieve with additive manufacturing processes has helped position us ahead of our competition. Previously, around two products in every ten would need a rework after the end-customer's first fitting. The AM250 has helped reduce this drastically. This reduction in reworks is a particular benefit for dentists as it helps reduce the amount of appointments needed for each customer, which has a significant effect on the revenue of the practice.
“In the future, Swift is planning to purchase another additive manufacturing system from Renishaw to further increase our production levels. We are also hoping to develop the manufacturing process of our other products, specifically our chrome removable partial dentures. Production levels currently sit at around 1000 [chromes] per month — designing and manufacturing these products using a digital process gives us the opportunity to increase our capacity, leading to job creation within the business.”