Handcuffs are only used on young offenders held in the Oberstown child detention facility in extreme circumstances, its director has insisted.
Appearing before an Oireachtas committee, Pat Bergin said use of the restraints when moving young people within the Oberstown Children Detention Campus was "very rare".
Mr Bergin was giving evidence to the Joint Committee on Children and Youth Affairs on management's response to a recent critical inspection report by HIQA.
The report highlighted that children had been held in separation in the north Dublin facility for more than a week.
March's inspection also flagged up two serious risks in relation to the administration of prescribed medication to a detainee and around the secure storage of medicines.
There have been outbreaks of serious rioting in the centre in recent times, a number of episodes where young people escaped and, last year, staff took industrial action.
Oberstown has capacity to accommodate 54 young people. The current population is around 40.
During questioning by committee members, Mr Bergin was pressed on the use of physical restraints in the centre.
Independent senator Joan Freeman expressed concern that handcuffs were used on young people.
"That absolutely offends me instantly on hearing that," she said.
Sinn Féin TD Denise Mitchell said she was "upset" by the use of handcuffs.
Mr Bergin noted that the majority of young people arrived at the centre from courts in handcuffs.
He said their use inside the centre was very limited, recalling four instances in the last year.
The director said they were not used when a volatile situation flared, but on a planned basis for moving high-risk young people from one place to another.
"The issue of handcuffs on campus, just to be clear, it's very rare and it's in exceptional circumstances," he said.
Mr Bergin was also pressed on instances of physical intervention by staff during volatile episodes.
He said they were becoming less frequent as staff were increasingly relying on dialogue to resolve situations.
Mr Bergin explained that when a problem flared with a young person, staff would always try to address it through "talking, talking, talking".
He said if dialogue failed to defuse matters, staff would conduct a risk assessment to determine whether a physical intervention was required.
The director said such interventions would involve two or three trained staff members holding the detainee on the ground until they calmed down.
Mr Bergin said there had been a series of positive developments and improvements in Oberstown since the HIQA report.
"Notwithstanding the progress, challenges remain and will to an extent always be part of a facility that is charged with detaining young people with a history of difficult behaviour," he told committee members.