R&D Story 01

Our Mission to Maintain Healthy Mouths

Dental care manufacturers have been trying to make the perfect device to clean between teeth for years. After pioneering wire-free interdental brushes, Sunstar set its focus on developing a design that would make it easier to clean between difficult-to-reach back teeth.

Cleaning the Gaps

Inflammation around the teeth is a common dental condition throughout the world. Periodontitis, or gum disease, develops when food debris stays between teeth long enough to form plaque that feeds millions of bacteria living in the mouth, which subsequently hardens and turns into tartar. This causes inflammation in the gums, and various other problems.

  • Food Debris

  • Plaque

  • Gum Inflammation




Prevention of periodontitis is simple in principle: clean off food particles and plaque before tartar builds up. Regular brushing alone, however, is not sufficient. To remove all food particles and dental plaque from the gaps, we need to use specialized devices like dental floss or interdental brushes.

An interdental brush is a tiny brush that is used to insert and clean between teeth. During their relatively short history, these little brushes have gone through quite a transformation in shape – from the original I-type, which is a straight pick with a brush on the tip, to the L-type, whose brush is attached at an angle – and in material – from wired brushes to Sunstar’s unique non-wired rubber bristles. Although these brushes have improved in functionality and usability with each evolution, Sunstar researchers are always striving for better, more effective products.

Prevention of periodontitis is simple in principle: clean off food particles and plaque before tartar builds up. Regular brushing alone, however, is not sufficient. To remove all food particles and dental plaque from the gaps, we need to use specialized devices like dental floss or interdental brushes.

An interdental brush is a tiny brush that is used to insert and clean between teeth. During their relatively short history, these little brushes have gone through quite a transformation in shape – from the original I-type, which is a straight pick with a brush on the tip, to the L-type, whose brush is attached at an angle – and in material – from wired brushes to Sunstar’s unique non-wired rubber bristles. Although these brushes have improved in functionality and usability with each evolution, Sunstar researchers are always striving for better, more effective products.

A Global Team on a Mission

After introducing the original I-type rubber-bristled Soft-Picks, Sunstar’s global team started to work on another type of pick that would make it easier to access teeth at the rear of the mouth. These back teeth have the shortest life span out of all teeth because they are hard to clean properly. The existing brushes were great for front teeth, but access to molars was limited. With the straight I-type brush, it was hard to reach between back teeth, and while it was easier with the angled tip of the L-type, the larger frame wasn’t as comfortable.

What the team aimed for in the initial design process was the user-friendliness and familiarity of a regular toothpick. “When people use toothpicks, they don’t really need a mirror. That’s the type of familiarity we wanted our clients to feel when using our product for back teeth”, a researcher on the team explained.

When people use toothpicks, they don’t really need a mirror. That’s the type of familiarity we wanted

The First and Only Curved Interdental Brush

“It was quite obvious from the start”, the researcher continues, looking back at the design process. “The curve made sense because it fits the mouth naturally. The tip slides into the gaps between molars without poking the cheek or requiring the user to put their fingers into their mouth”. It was also great for mechanical reasons – the curved shape gave the brush the strength and durability needed to reach and clean back teeth while staying slim to maximize comfort.

The team produced over 30 sketches to come up with a design that fulfilled all requirements. It was then refined to the millimeter to meet the precision dental care products need. The team based all measurements on one mouth model because the size of the interdental gap is similar across ethnicities despite slight differences in jaw size.

A New Generation of Rubber-tipped Interdental Brush

When developing “Soft-Picks Advanced”, the global team decided that they were going to use Sunstar’s pioneering wire-free tip approach, already being used for the original Soft-Picks, instead of a traditional wire tipped product which dominated the market. Free of any metal wires, the bristled rubber tip is directly attached to the handle, feeling softer and gentler on the gums compared to wired brushes.

The team produced over 30 sketches to come up with a design that fulfilled all requirements

When the rubber tip was being developed for the original Soft-Picks, selecting the right materials was essential. The soft exterior made the brush more comfortable and less aggressive than wired brushes, while the core had to be hard enough to be inserted between the teeth without bending or breaking.

The team searched for the perfect combination. “We have a big stock of materials we can test here, and we tested many different combinations of materials to find the exact hard-soft combination”. The selection process is a cycle of trial and error.

After extensive tests, they found what they were looking for: a firm but soft rubber for the bristles, and for the core, a material with the necessary stiffness and enough flexibility to ensure perfect performance of the product.

The team produced over 30 sketches to come up with a design that fulfilled all requirements

Testing the Prototypes

Testing the Prototypes

With the design and materials ready, it was time to test the prototypes to fine-tune the details. First off, the team evaluated the durability and bendability of the designs by using a special device to apply different levels of force to the tip of the prototype. In addition to these mechanical tests, they verified the safety of the materials themselves, which is regularly done even after the product is on the market.

More Comfortable, Easier to use, and Better Cleaning

When used in combination with tooth brushing, there were no overall statistically significant differences between the two interdental devices in reducing plaque and gingival inflammation. Participants without previous experience of interdental cleaning considered the Soft-Picks more pleasant to use. The perception of the participants that this product fit well between the molars was supported by clinical outcomes at the sites with respect to bleeding and plaque scores (1).

Soft-Picks Advanced as compared to an existing interdental wired brush.

  • Soft-Picks Advanced
  • Existing interdental wired brush

What’s Next?

The team is already working on new concepts and products. When asked for details, a researcher from the team laughed and said, “Well, it’s confidential of course, but I can say that some of the ideas and future products are going to be quite revolutionary.”

Some of the ideas and products are going to be quite revolutionary


Find out more

Soft-Picks Advanced*

Soft-Picks Advanced is the latest addition to Sunstar’s range of interdental cleaners. It has a characteristic curved shape, the first and only in its category, so users can easily clean the hard-to-reach gaps between molars in the back of the mouth. Its tapered, rubber-bristle tip cleans comfortably, and is safe for orthodontics and dentures.

Learn more

*Currently available in Japan and the EU

References

  • 2014

    (1) D.E.SLOT, NIENKE L. HENNEQUIN-HOENDERDOS, E. VAN DER SLUIJS, G.A. VAN DER WEIJDEN. Soft-Rubber-Interdental-Cleaner compared to an Interdental Brush on Dental Plaque/Gingivitis/Gingival Abrasion Scores. Poster session presented at: IADR 92nd General Session; 2014 June 25-28; Cape Town, South Africa

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