Just a third of adults attended dental appointments as the coronavirus pandemic brought disruption to Cornwall, figures suggest.
NHS England data shows a steep drop in people visiting the dentist in 2020 and 2021, with millions across England missing check-ups and treatment.
The figures are proof that NHS dentistry is at the "last chance saloon" and in urgent need of reform, according to the British Dental Association.
In the two years to December 2021, 155,985 adults in Cornwall attended an appointment – the equivalent of 34% of the population.
That is significantly down on the 24 months to December 2019 when 224,457 – 49% – attended.
Between March and June 2020, dental practices were instructed to close and defer routine, non-urgent dental care to limit the spread of Covid-19.
According to the BDA, more than a year’s worth of dentistry has been lost to the pandemic so far, with the association’s research showing 40 million fewer courses of treatment were delivered between April 2020 and December 2021.
BDA chairman Eddie Crouch said every missed appointment translates to bottled up problems and widening oral health inequality, which could see patients left requiring more extensive and costly interventions.
The association has urged the Government to deliver "meaningful and urgent reform" to the industry, saying underfunding, cuts and failed contracts had also contributed to the problems within the sector.
Mr Crouch said dentists were leaving the NHS and warned recovery from the pandemic would be impossible "if ministers fail to halt the exodus from a demoralised workforce".
He said: "For the sake of our patients real, urgent reform cannot remain stuck on the Government’s ’too difficult’ list."
A spokeswoman for the Department of Health and Social Care said it had taken "unprecedented action" to support the sector during the pandemic, adding: "Levels of dental treatment are increasing and urgent care is back to pre-pandemic levels thanks to the hard work of staff."
Data relating to children is recorded on an annual basis and shows that the volume of dentist visits, which declined significantly during the pandemic, showed signs of improvement last year.
Nationally, 5.1 million children were seen by an NHS dentist in the year to December – 43% of the child population.
This was up from 3.6 million (30%) the year before, but still significantly down on the seven million (58%) seen in 2019, prior to the pandemic.
Last year, 41% of Cornwall’s child population – 44,695 youngsters – saw their dentist, compared to 28% in 2020 and 58% in 2019.
An NHS spokeswoman said more than 600 urgent dental health hubs had been established in response to the pandemic and said NHS England had provided financial support to dental practices while Covid-19 prevented them from working at full capacity.
She added: "The NHS is now getting key services like dentistry back to pre-pandemic levels – injecting an extra £50 million into routine services, which will help provide check-ups and treatment."