Assistant Gwent Coroner Geraint Williams recorded narrative conclusions for June Hamer, 71, Stanley Bradford, 76, Edith Evans, 85, Evelyn Jones, 87, and William Hickman, 71.
He said a sixth resident, Stanley James, 89, had died from natural causes.
The inquest in Newport Gwent heard the pensioners all died between 2003 and 2005 having been residents at the nursing home in New Tredegar.
In a lengthy summing up, Mr Williams gave a withering summary of a catalogue of failings – accusing managers of “dehumanising” and “warehousing” the elderly.
He accused the owners and staff at the home of a “gross betrayal of the trust” placed in them by the relatives of the residents by keeping them in the dark of the poor standards of care.
Mr Williams said the authorities should have taken more significant action against Dr Das in the autumn of 2004 as they knew about the deaths of Mrs Hamer and Mr Hickman and ongoing concerns at Brithdir.
“The level of extreme concern voiced in the meeting of October, the finding at that meeting that residents were subject of institutional abuse, the fact of the deaths only months earlier of Mrs Hamer and Mr Hickman, the evidence of years of continued identical failings, all demonstrate the risk to residents was serious,” Mr Williams said.
“I don’t doubt that the external agency assistance that was in place played in a part in reducing the level of risk.
“However, it did not diminish that level to a point at which it could be said it was a risk and not a serious risk.
“It is not without significance that Mr Bradford, Mrs Evans and Mrs Jones were to die in the following year have suffered from the most appalling neglect at the hands of the staff at Brithdir in very much the same circumstances of concern identified in the meeting of October 2004.
“In my judgement it was a plain as a pikestaff that in October 2004 there was a serious risk to the life, health and wellbeing of residents at Brithdir.
“I accept there were other considerations which would have informed the decision whether or not to take the urgent cancellation procedure route, at least the effect on existing residents.”
He added: “I do find the decision not to institute the urgent cancellation route was a missed opportunity to act to protect the residents of Brithdir.
“In my judgment the individuals concerned and therefore the state agencies were largely hamstrung by the legislation and the regulations in force at the time.”