Founder of Slate Flosser Brynn MacLennan Wants Her Company to Make People Feel Confident in Their Dental Routine: We're Doing 'Something Meaningful'

Brynn MacLennan never thought she would own an oral health company.

"If you asked me that 20 years ago, I would have laughed," she exclusively tells OK!. "I studied product design at Brigham Young University and always thought I’d build consumer products — just not dental ones. That changed when Dr. Snyder and I purchased a dental practice in Spokane, Washington. I wasn’t the clinician — I was observing patterns. And one thing became very clear: patients knew they should floss, but most weren’t doing it consistently. Even highly educated, successful adults struggled to make it a habit."

"The ones who did floss often used disposable floss picks, but we weren’t seeing meaningful improvements in gum health. That’s when the product designer in me started asking questions. What if the issue wasn’t motivation? What if flossing simply wasn’t designed well enough for real life?" she continues.

Through her patients, she saw "firsthand how much anxiety people carry about going to the dentist."

"Studies show over 80 percent of adults experience dental anxiety. Most people assume that fear comes from bad childhood experiences — but we began to believe it was often something deeper: the stress of knowing you haven’t been taking care of your mouth the way you should," she explains, adding that they realized "prevention could change that emotional cycle."

"If flossing were easier, faster, and actually effective, people could feel more confident at their appointments. They could prevent gum disease instead of reacting to it. They could protect not just their teeth, but their overall health," she shares.

From there, Slate Flosser was born, with the mission of making flossing so simple and effective that people actually do it.

"It became obvious to us inside our dental practice. Patients expected to be asked, 'Do you floss?' at every appointment — and many would smile and say yes — but they had no real intention of flossing consistently. It wasn’t a motivation problem. It was a usability problem. The options on the market weren’t solving it. Disposable floss picks weren’t delivering meaningful improvements in gum health, and water flossers require time, space, and commitment that most people simply don’t maintain. Meanwhile, nearly 50 percent of adults in the U.S. have some form of gum disease — and by age 60, that number rises to about 70 percent," she says. "The need was there, but the at-home solution wasn’t. At the same time, we were watching the broader conversation around longevity and the microbiome grow. People care deeply about living longer and better — but many don’t realize that gum health is directly connected to heart health, brain health and inflammation throughout the body. Flossing isn’t cosmetic. It’s preventative care. Dentists want patients to use three tools beyond a toothbrush: floss, an interproximal brush, and a tongue scraper. But asking someone to adopt multiple new tools is unrealistic. So, we asked a simple question: what if it were all one tool? That’s what led us to design a 3-in-1 solution — something that actually removes biofilm, stimulates the gums, and makes it easier for people to take control of their health at home. Because the gold standard is still string floss — but if people aren’t using it, the design has to evolve."

Most people develop gum disease for one simple reason: plaque hardens into tartar in about 24-48 hours, and over time, it can become worse.

Though traditional floss works, the reality is, most people don't do it correctly.

"So when we designed Slate, we asked: how do we remove the technique barrier? Our 3-in-1 floss head combines woven floss, soft gum sweeps (small interdental brushes), and a built-in tongue scraper. The woven floss removes plaque between teeth, while the gum sweeps gently stimulate the gums right where the tooth and gum meet — the area most people miss. That stimulation matters because healthy gums aren’t just about cleanliness; they ’re about circulation and inflammation control. What many people don’t realize is that gum disease doesn’t stay in your mouth. Long-term gum disease has been associated with a significantly higher risk of cognitive decline. Men with periodontal disease are more likely to experience erectile dysfunction. Pregnant women with untreated gum inflammation have higher rates of preterm birth and low birth weight. And inflammation in the mouth is closely tied to heart health — which is why dental clearance is often required before certain cardiac procedures. Slate is designed to make daily prevention easier — because when flossing becomes simple and effective, people actually do it. And that small habit has an impact far beyond your smile," she shares.

From the get-go, the founder knew the tool had be "intuitive."

"If something feels awkward or hard to hold, people won’t use it consistently. So we focused heavily on ergonomics and dexterity. The handle was shaped to feel balanced and comfortable in your hand, making it easy to maneuver — even in the back of the mouth," she says. "We spent a tremendous amount of time studying how teeth and gums actually interact — straight teeth, crowded teeth, tight contacts, gum recession — and how real people move when they floss. Traditional string floss works, but it’s technique-sensitive. Most people don’t naturally hug the tooth or stimulate the gumline the way a hygienist would recommend. That’s why we paired woven floss with soft gum sweeps and gentle sonic vibrations. The vibrations help disrupt plaque and biofilm, while the gum sweeps stimulate the area where the tooth and gum meet — one of the most important and commonly missed zones for preventing gum disease."

She adds: "And because a significant amount of oral bacteria live on the tongue, we integrated a built-in tongue scraper so the entire routine could happen with one tool. We began designing Slate in 2019. It took nearly three years before we had a product ready to sell in November 2022. During that time, we worked closely with engineers, dentists and manufacturing partners across multiple iterations to refine everything — from the motor strength to the floss tension to the softness of the gum sweeps. Every detail was tested and adjusted with one goal in mind: make it easier for people to effectively disrupt bacteria at home. Slate is the result of thousands of hours of design, clinical insight and engineering — all centered around helping people take control of their oral health in a way that fits into real life."

Since the entrepreneur cares "tremendously" about preventative health, she wants to make sure people live longer and protect their brains and hearts.

"But what’s the point of living to 90 if the last 20 years aren’t vibrant?" she asks. "The mouth is one of the biggest gateways to inflammation in the body. Gum disease is chronic inflammation. And chronic inflammation is linked to so many of the conditions people fear most as they age. Yet flossing — one of the simplest preventative habits — is the one people skip. My hope is simple: that people actually floss daily.If we can remove the friction and make flossing easy and effective, we can change behavior. And when daily habits change, long-term outcomes change. I want people to feel empowered — to know they ’re doing something proactive for their health in under two minutes a day. And on a lighter note? I want people to smile confidently. Healthy gums mean healthier teeth, fresher breath, and fewer uncomfortable dental visits. Prevention isn’t dramatic. It’s daily. And small, consistent care adds up in a powerful way."

For MacLennan, watching the brand take off has been "rewarding," but she also has to balance her company all while raising five kids.

"I genuinely love building, creating and solving problems. I won’t pretend there’s perfect balance — there isn’t. It’s more about being intentional with my time and accepting that some seasons lean heavier in one direction than the other," she admits. "The weight of responsibility is real. Every major decision — strategy, hiring, growth, capital —ultimately stops with me. I’m not building a lifestyle brand. I want to build something that changes behavior globally. I want to make flossing accessible and normalized everywhere, because I believe it impacts long-term health in a meaningful way. That kind of ambition requires constant strategic thinking and forward motion, and that can be mentally demanding. One of the hardest parts, though, is people. I care greatly about our team. When you build a company from the ground up, every employee matters personally. Letting someone go — even when it’s the right decision for the company — is incredibly difficult. You feel the weight of that. But leadership means making hard choices in service of the mission. And I remind myself often: if we do this well, we’re not just growing a company — we’re helping people live healthier lives. That makes the responsibility worth it."

Still, she's excited about what's next.

"Watching Slate grow has been incredibly rewarding. We started as a direct-to-consumer brand, then expanded to Amazon, and now seeing our product on shelves at Target has been surreal. Scaling from an idea into something people can pick up in a national retailer is exciting — but what matters most to me is the impact behind it," she notes.

"One of my favorite things is reading customer emails. Every person who orders from our website can reply directly to me, and many do. They tell me their gums stopped bleeding. That their hygienist noticed a difference. That for the first time, they feel like they can actually stay on top of their oral health. We’ve had customers who struggled with gum disease for years — feeling like it was just something they had to live with. Then they start using Slate consistently, and they see improvement. When someone takes the time to write and say, 'This changed my routine,' or 'My gums are finally healthier,' it makes every hard decision, every late night, every challenge worth it. Helping people shift from reactive to preventative care — and seeing real health improvements because of it — has been the best part. Growth is exciting. Retail is exciting. But changing daily habits that lead to healthier lives is what truly matters to me," she continues.

Ultimately, MacLennan is looking forward to growing Slate into a household name — "not for ego, but for access."

"We want to meet people wherever they shop, whether that’s retail, Amazon, or our website. The goal has always been bigger than just selling a product. We want people to floss. Truly, I care more about people becoming healthier than about what brand they choose. Of course, we believe Slate makes flossing easier and more effective, which is why we’re so passionate about it. But at the end of the day, if someone builds a daily habit that reduces inflammation and improves their long-term health, that’s a win. I hope we’re available in multiple countries and found everywhere oral care is sold — right alongside toothpaste and toothbrushes. Because flossing shouldn’t feel optional or complicated. It should be a normal, accessible part of everyday health," she states.

"We’re a women-owned business, and that’s something I’m incredibly proud of. Building Slate has shown me how much opportunity there is for female founders — and also how many barriers still exist. I would love to use our growth as a platform to support other women entrepreneurs, especially in learning how to scale, navigate funding and build sustainable companies. I’m also passionate about creating meaningful opportunities for mothers. I know firsthand how challenging it can be to pursue ambitious work while raising a family. At Slate, I love hiring talented moms and building a culture where flexibility, support and performance can coexist. When women feel supported both professionally and personally, they do extraordinary things. If we can build a company that not only improves health but also helps empower more women to grow businesses and lead confidently, that’s impact beyond product — and that’s something I care so much about," she continues.

MacLennan hopes the tool changes the game.

"Healthy gums reduce inflammation in the body, and inflammation is connected to so many of the conditions people fear as they age. If something as simple as flossing consistently can help support overall health, that’s powerful. But beyond the clinical side, there’s also an emotional side. Dental anxiety is real. So many people walk into appointments feeling embarrassed or ashamed because they know they haven’t been flossing. When someone starts taking control at home — when their gums stop bleeding, when their hygienist notices improvement — that anxiety begins to fade. And then there’s confidence. Fresh breath. A healthy smile. Feeling good when you laugh, talk, or get close to someone. Those small things change how we show up in the world. If Slate helps people feel healthier, more confident, and more in control of their own care — even in a small way — then we’ve done something meaningful," she concludes.