How do you know when it’s time to stop brushing? You don’t, according to Ameya Mehen­dale, who recently grad­u­ated from the master’s pro­gram in chem­ical engi­neering. Instead, he said, you spit out the tooth­paste at an arbi­trary point in your dental hygiene rou­tine. But with 85 per­cent of the U.S. pop­u­la­tion suf­fering from some form of peri­odontal dis­ease, we seem to be off in our tooth­brush timing.

To combat the quandry, Mehen­dale came up with an idea for a smart tooth­brush while chat­ting with friends about how engi­neering solu­tions can solve real-​​world prob­lems. Then he had a chance to develop a real plan for the product this spring at the Entre­pre­neurs Club’s annual Engi­neers for the Greater Good event.

In col­lab­o­ra­tion with five other engi­neering students–Jeff Kent, Esfandiar Keikhosrowzadeh, Samuel Levine, Getao Li, and Dan Shores–Mehendale spent three days holed up in Snell Engi­neering Center fleshing out the details of the tooth­brush. It would work in con­junc­tion with flu­o­res­cent tooth­paste that adheres to bac­teria and glows when shone with cer­tain wave­lengths of light. That light would shine from an LED on the smart toothbrush’s head, according to Mehen­dale, and the flu­o­res­cence would be detected with a sensor beside it. When most of the bac­teria have been washed away, the flu­o­res­cence would cease and a red light on the tooth­brush handle would turn green, indi­cating that brusher’s teeth are clean.

Stu­dent Dan Shores designed the tooth­brush using Auto CAD. Image cour­tesy of Sam Levine.

You could be in your kitchen brushing your teeth. You don’t need to look in the mirror,” Mehen­dale said. “You don’t see the flu­o­res­cence, because it’s detected by the toothbrush.”

During the three-​​day event, the team mem­bers did some market research to see if their solu­tion would be desir­able. Then they researched sim­ilar tech­nolo­gies in the field and found nothing quite as spe­cific as their device. The young researchers drew up AutoCAD plans for the tooth­brush and deter­mined likely market costs. At the end of the event„ team mem­bers pre­sented their research to a panel of three judges, including Scott Bailey, director of part­ner­ships at Mass Chal­lenge, who named it the first-​​place winner.

Backed by $1,500 in prize money to get the project off the ground, Mehen­dale is eager to take it to the next stage.