Some NHS dental patients face a two-year wait for an appointment - while others have been advised to buy a home kit and "treat themselves" amid a growing crisis for care, according to a watchdog.
Healthwatch England said one patient was offered a procedure for £1,700, which was £60 on the NHS.
Another patient was told to use a nail file to deal with a broken tooth, and others were advised to "buy dental repair kits" to treat their problem at home.
The watchdog said the COVID-19 pandemic had "exacerbated the human impact of years of structural issues in NHS dentistry and is now pushing it to crisis point".
Hundreds of people contacted Healthwatch England between October and December last year about dentistry issues in the health service, with the lack of appointments being the most common complaint.
Other issues reported to the watchdog included:
• One person who was charged £500 for the extraction of a single tooth
• A patient who was told that NHS care would be "60% successful", but if they were willing to pay an extra £450 for private care, the odds would increase to 90%
• A pregnant woman with a suspected abscess who waited months for care - and was then told the only place she could receive help was a 45-minute drive away
Imelda Redmond, general director of Healthwatch England, said people "have been really let down".
She told Sky News: "We did hear from people right across the country during the pandemic to say that they were having difficulty accessing dental treatment at a reasonable time and at a reasonable price.
"The quality of information is really poor. Some people are ringing 50 to 60 dentists before they can actually get an appointment.
"And then, because of the pressure that dentists are under, they are resorting to asking people to do self-managed jobs. The scale of the distress that people have been through is extraordinary.
"Dental care is a critical part of our overall care services. People are having terrible abscesses and having three courses of antibiotics. There are people who will have mouth cancer and won't have it diagnosed during this time."
She called on the government to take action to "rebuild dentistry", adding: "It is a really difficult situation for dentists.
"We are a year into the pandemic now, so it is really important that this is given quite urgent attention."
Dentists have been ordered to treat 45% of patients of their pre-pandemic levels - but have raised serious concerns about increasing footfall in practices amid continuing fears over COVID-19.