Glen Heavenor was inspired to act after noticing the poor brushing techniques of many of his patients.
The 50-year-old inventor claims his design increases control and cuts joint strain.
Mr Heavenor is now hoping to modify the easy-use handle for cutlery, razors, hairdryers and pens.
"
I knew instinctively when I came up with the design that I was on to something
"
Glen Heavenor
Mr Heavenor, whose daughter Kate presents children's TV on the BBC, has already seen his handle design used on prams, hairbrushes and pans.
"Bending toothbrushes into different shapes is something you can do very easily because you can heat them up," he said.
"I knew instinctively when I came up with the design that I was on to something.
"When I sanded that first design in the bathroom it was like giving birth to a toothbrush."
The inventor said the technology, which he has patented under the name Rotilt, increases control of objects and can cut joint strain.
Lottery support
The handle, which spirals and ends with a bump, follows the shape of bones in the forearms and reduces awkward movements.
Although his toothbrush was initially rejected, the dentist said he was determined to try again after securing deals with Mothercare for stroller handles and Scots firm Albyn for hairbrushes.
Mr Heavenor was given the cash after applying to the National Endowment for Science, Technology and the Arts (Nesta), a lottery-backed group to support inventors and artists, giving him an extra day off work to spend on new designs.
A spokesman for the group said: "Hopefully, with our support, Glen will be able to devote the necessary time to give the project every chance of success."