An 88-year-old rest-home patient suffering dementia was made to wear someone else's dirty false teeth after her own were lost, her family says.
The dentures had "horrible black bits" between the teeth and "what looked like chewing gum" to hold them in place.
Elleanor Tipler's daughter, Rosey Ross, was horrified after making the discovery at Tauranga's Melrose Lifestyle Care and Village - and says her mother has been shown a lack of respect and dignity.
She has told her story exclusively to the Bay of Plenty Times after feeling she was getting nowhere with her complaints to the rest home and politicians.
Mrs Ross said her mother had Alzheimer's disease and a broken hip.
She removed her mother's bottom denture when she complained of gum ulcers during a visit in early February. Mrs Ross told the nurses and put the teeth in a drawer in her mother's room in the rest home's hospital wing.
Her mother was left with her top dentures only.
On February 17, Mrs Ross noticed her mother sucking on her bottom lip and struggling to eat so went to retrieve her bottom dentures, only to find they were missing.
The nursing staff were told but "no one knew anything or seemed to care", she said. On her next visit, five days later, Mrs Ross noticed her mother's bottom lip protruding and on closer inspection found she was wearing someone else's bottom dentures.
"These teeth were disgusting, with horrible black bits between the teeth, and what looked like chewing gum at the back to hold them in place," she said.
"I was disgusted that they were someone else's teeth."
Mrs Ross said the staff should have simply conceded they had lost them.
When she complained, she said a staff member admitted the dentures were someone else's but thought they were a good fit.
"Melrose have lost my mother's teeth, then totally disregarded her respect and dignity by placing someone else's teeth in her mouth. This is disgusting and totally against the rights of a person with a disability."
A meeting between Mrs Ross and rest-home management was arranged for last week but she said the rest-home cancelled it on short notice and it has not yet been rescheduled.
Oceania Group regional manager Mark Durling said he was aware of the complaint but did not know the details of how the teeth were lost or where the other set came from.
An investigation had started: "I can assure you that it should not happen and if it did happen I'm not sure how it happened."
Tauranga Age Concern chief executive Mike Tyrer said such treatment was unacceptable.
"It is a problem that we hear of from time to time when these people are not respected and they are treated like second-class citizens, which is something we are trying to rectify," Mr Tyrer said.
He could recall two complaints over three years regarding the treatment of elderly in homes which Age Concern had been asked to investigate.