Breaking down the numbers behind our 5th clinical study against knockoffs
Most people have seen U-shaped toothbrushes online. Some cost $20, others $200. They look similar from the outside, but clinically, they’re not even close.
To help cut through the noise, Autobrush participated in an examiner-blinded clinical study comparing its ADA-Accepted Sonic Pro toothbrush with two popular silicone knockoff models.
In an examiner-blinded study, participants use both brushes, but the examiner scoring their plaque levels is never told which brush was used. This prevents bias and ensures that all results are based solely on cleaning performance, not expectations. The examiner evaluates each session the same way, making the comparison between Autobrush and knockoffs fair, objective, and scientifically credible.
The goal was simple: measure how well each brush removes plaque across every area of the mouth.
The full report is scientific, technical, and dense - so we turned it into the guide below: a clear explanation of what was tested, what the numbers mean, and what parents and adults should take away.
Let’s break it down.
What was this study designed to find out?
The researchers wanted to answer one main question:
“Do U-shaped silicone brushes actually clean teeth, and how do they compare to Autobrush?”
To do that, they measured plaque using a standard clinical scoring method called the Lobene-Soparkar Plaque Index (LSPI).
This index scores plaque on a scale from 0 (no plaque) to 5 (heavy plaque) across multiple surfaces in the mouth.
Before brushing → LSPI score
After brushing → LSPI score
The difference between those two numbers shows exactly how much plaque a brush removed.
(From: Clinical Methods)
Who participated?
The study included:
- 41 total volunteers
- Ages 5-12 (kids) and 18-65 (adults)
- 100% completed the study
- Zero adverse events
That matters because it shows the study was both safe and reliable, and reflects real brushing needs across age groups.
(From: Demographics & Safety)
How the study worked
This was a randomized, examiner-blind, crossover trial, one of the strongest study designs for comparing two products.
Every participant:
- Used Autobrush Sonic Pro for one period
- Used a silicone knockoff brush for another period
- Was examined by the same blinded dental examiner
- Brushed for 30 seconds, twice a day
- Used standard Crest toothpaste
Because each participant used both brushes, they essentially acted as their own control (eliminating bias).
(From: Study Design)
So… what did the numbers actually show?
Here’s the part everyone wants to know.
Autobrush removed significantly more plaque than silicone knockoff brushes, on every surface measured in the study.
This includes:
Whole-Mouth Cleaning Performance: Autobrush cleaned up to 6.9× better overall
(Whole-mouth mean plaque reduction advantage)
Hard-to-Reach Areas: Autobrush cleaned up to 10× better in posterior regions
(Back molars, where knockoffs performed the worst)
Gumline (Gingival Margin): Autobrush cleaned up to 5.1× better
Gumline is where plaque most often leads to gingivitis, and silicone brushes showed extremely low effectiveness here.
Between the Teeth (Proximal Surfaces): Autobrush cleaned up to 7× better
Knockoff brushes failed to adequately agitate bristles between teeth due to rigid silicone design.
Front of the Teeth (Facial Surfaces): Autobrush cleaned up to 6.4× better
This is one of the surfaces where silicone brushes underperformed the most consistently.
Silicone U-shaped brushes struggled in almost all categories, especially in the places plaque tends to cause the most problems.
(From: Results Summary)
Why hard-to-reach areas matter most
Most dental problems start in three places:
- The gumline
- Between teeth
- The back molars
The study found the biggest performance gap in exactly these areas, where silicone brushes showed very limited effectiveness.
Autobrush’s nylon bristles and 30-second sonic motion made a measurable difference here, the same cleaning technology used in conventional sonic toothbrushes.
(From: Surface-by-Surface Scoring)
Why silicone knockoff brushes struggle
The study helps explain why cheaper U-shaped brushes don’t perform well:
1. Silicone cannot remove plaque as effectively as nylon bristles.
It simply doesn’t create the friction needed for plaque disruption.
2. Knockoff silicone brushes are marketed as hands-free.
Independent testing shows that their low-power motors cannot effectively remove plaque without manual movement.
3. Many designs don’t fully cover all tooth surfaces.
Especially back molars and the gumline.
4. No ADA acceptance or clinical testing.
Meaning they’re not validated for plaque removal.
The study quantified the gap that parents and dentists have been noticing for years.
Safety findings
The good news:
No adverse events were reported, and all 41 participants completed the study.
Both adults and kids tolerated the brushing protocol well.
(From: Safety Assessment)
What this means for parents and everyday brushers
This clinical study confirms what many people suspected:
Not all U-shaped brushes are the same and most are not clinically effective.
For many families, this matters because:
- Kids often rush brushing
- Adults may miss gumline areas
- Neurodivergent users may struggle with sensory discomfort
- Busy households need simplicity without sacrificing cleaning quality
A 30-second brush only matters if it actually works.
This study shows that Autobrush does.
Link to the full clinical study here
