Some people do not go the dentist for a fear of syringes, thereby risking a worsening of untreated tooth damage. However, some dental practices offer patients an alternative – a device for computer-controlled, pain-free local anaesthesia, which its developers call a “magic wand”: The Wand – STA System from Milestone Scientific.
For the past 25 years, the US-based company specialising in injection technology has been manufacturing the system’s single-use components from CYROLITE by Röhm – a transparent, acrylic-based plastic especially for medical applications.
Proven material for medical technology
“All types of CYROLITE meet the stringent USP Class VI material standard and the ISO 10993-1 standard for plastics used in pharmaceutical and medical technology. They are free from bisphenol A, are biocompatible and have ultra-low extractables and leachables characteristics in addition to great chemical resistance,” explains Michael Zadrozny, strategic account manager medical at Röhm. “CYROLITE moulding compounds are used to manufacture diagnostic equipment, as well as disposable devices such as IV connectors, Y-sites, and luer locks, catheter components, filter housings and syringes.” Two parts of the hand piece of The Wand STA are also made of CYROLITE: the cartridge for the anaesthetic container, which is secured in the device by a bayonet lock, and the applicator, a roughly 20-centimetre-long (8-inch) thin tube at the end of which is a thin injection needle.
For injections without pressure pain
STA stands for Single Tooth Anaesthesia System. The device not only allows pain-free injections, but also the precise anaesthetisation of individual teeth. This offers the benefit that once the treatment has ended, larger sections of the jaw including the cheeks are not numb for several hours. According to Milestone Scientific, the entire procedure is more comfortable for patients than conventional syringe injections.
Although all dentists are likely convinced that they can carry out pain-free injections by hand, pushing the injection liquid into human tissue can cause enormous pressure. This is the painful burst-effect so many patients are afraid of. The slower the injection is applied, the lower the level of pain. When local anaesthesia is applied with a syringe, patients must rely on the intuition and sensitivity of the treating physician. With the STA system, the computer controls the optimal needle position, exit pressure of tip of the needle and the flow rate of the anaesthetic so precisely and evenly that patients hardly notice what is happening. The dentist must merely guide the applicator with the cannula to the injection site and activate the device via a foot pedal.
CYROLITE enables light yet stable components
Compared to the bulky cylinder ampule syringes with stainless steel housing, The Wand – STA System’s applicator made of CYROLITE is as light as a feather. The injection device is easy to handle thanks to its low weight and pen-like shape. Like other dental instruments, dentists can hold the long, thin “magic wand” between three fingertips and execute precise bi-rotational movements.
Milestone Scientific offers specific hand pieces for all commonly used anaesthesia technologies. Applicators with flexible length adjustments have proven especially practical: These models with tubes made of CYROLITE have multiple notches (predetermined breaking points) and can be shortened by snapping them off. This is convenient when applying a local anaesthesia to numb the front teeth and makes it easier to treat children and nervous patients. “Dentists can hide the end with the needle in their hand and numb the damaged tooth virtually unnoticed, actually like a magician with a magic wand,” states Tom Cheng, who is responsible for product development and production at Milestone Scientific.
Very good flow characteristics during injection moulding
The processing properties of CYROLITE GS-90 support the continuous development of the product design of the The Wand - STA System’s hand pieces. With a high heat deflection temperature and excellent melt flow rate, the moulding compound is ideal for precise injection moulding and extrusion of thin-walled and complex moulded parts with high stability. This CYROLITE grade is especially impact resistant. Furthermore, it is compatible for direct contact with body fluids, many chemicals, and drugs – in this case anaesthetics. Components made of CYROLITE moulding compounds can be solvent and thermal bonded as well as ultrasonic or spin-welded to PVC hoses and other plastic components.
Undiminished transparency after gamma sterilisation
The hand pieces used for The Wand are designed for single use and are delivered in sterile packaging. This is why the outstanding material resistance of CYROLITE GS-90 exhibited during sterilisation with gamma rays (although it is also suited for EtO gas and E-beam sterilisation) was a crucial factor in Milestone Scientific’s decision to select this medical plastic from Röhm. “During our material testing, CYROLITE GS-90 was still absolutely transparent, without any cloudiness, discolouration or embrittlement, after a three-year stability test,” Cheng confirms. He also explains why it is so important that the components are transparent: “The transparent cartridge allows the dentist to see whether the anaesthetic is being delivered. And the transparent tube of the applicator allows them to visually check that the needle has not hit a blood vessel during the injection.”
Röhm supplies moulding compounds with consistent quality
“We greatly appreciate that Röhm has been supplying CYROLITE moulding compound reliably for such a long time and in a consistently high quality. We have produced nearly 15 million The Wand STA devices over the past 25 years, which we have sold in 45 countries. The moulding compound for the hand pieces was always immaculate and we have no problems ever since,” Cheng adds.