The "distraught" boss of a dental nurse was admitted to hospital and suffered from seizures three days after the nurse tried to poison her at the surgery, a court heard today.
Ravinder Kaur, 34, is charged with administering a "poison or noxious substance with intent" after she allegedly put mercury amalgam - a substance used in dental fillings - into a cup of coffee she made for her boss Laura Knowles.
Assistant dental nurse Kaur, who denies the charge, is accused of slipping the substance into Laura Knowles' cup of coffee at a dental practice in Shefford, Bedfordshire, on Friday March 16 last year.
Ms Knowles, 36, the practice manager at the Shams Moopen Dental Practice, suffered with what she described as "severe period pains" initially, but her symptoms worsened.
Ms Knowles told the jury that over the weekend she had bouts of dizziness, diarrhoea and vomiting.
On her return to work on Monday, Ms Knowles had to be hospitalised due to having a seizure - "the type people suffer when they have an epileptic fit", according to Rupert Bowers, defending.
She also lost consciousness.
Ms Knowles told the jury she attributes all of her symptoms to the mercury, but admitted that to this day she has "no knowledge whatsoever" regarding the consequences of ingesting the substance.
Despite the pains and sickness, Ms Knowles said it was the hurt she felt which affected her most in the wake of the alleged incident.
"I was distraught for the whole day and beyond," she said.
Mr Bowers' questioning of Ms Knowles painted a picture of a workplace where there was "disharmony" in the run-up to 16 March.
Ms Knowles told the court the surgery was "less than harmonious", and spoke about a dentist in the surgery requesting not to work with Kaur and in turn Kaur refusing to work with another dentist.
On Kaur's refusal to work with one of the dentists, Ms Knowles said: "They had a clash of personality. Both had come to me with separate issues."
Ms Knowles told the jury about how Kaur's relationship with a fellow dental nurse had "deteriorated so badly it was affecting patients coming into the surgery".
She said there was a culture of complaining about fellow staff members, describing the extent as "certainly week on week", and acknowledged that "general sniping" was commonplace.
Ms Knowles herself was spoken to by Dr Shams Moopen - the practice owner - about a letter he had received from a dental nurse complaining about Knowles' "preferential treatment" of Kaur, the woman accused of putting mercury in her coffee.
Ms Knowles said he spoke to her about the "disharmony within the practice" and said staff would have to "behave more appropriately".
Despite the discontent in the surgery, she believed she was on good terms with Kaur, telling the jury: "I considered myself to be Ravi's friend and mentor."
Mr Bowers told the jury that a letter sent to Kaur by Dr Moopen following a disciplinary meeting on 13 March - described as a final warning - was withdrawn by him on 29 March and he also apologised.
The letter said Kaur had "serious disagreements" with colleagues which "disrupted the smooth running of the surgery".
It suggested that she had left patients in the dentist's chair because she believed it was time for her to have her lunch.
The letter warned her that any future misconduct could result in her dismissal.