Dunne, a garda for 23 years, was the children's liaison officer at Pearse Street Garda Station from 1962 to 1976.
He was also a leader of a scout troop, and two of his victims were polio sufferers whom he recruited through his work with disabled scouts.
All four victims were present in Limerick Circuit Criminal Court yesterday.
Judge Carroll Moran handed down a two-year sentence, but suspended 18 months of it.
His victims came forward more than 40 years later, following the 2009 publication of the Ryan report on sexual abuse in the Dublin archdiocese.
Dunne admitted the offences to investigating officers in 2011.
"He robbed the boys of their innocence," the judge said.
Speaking afterwards, one of Dunne's victim -- now aged 56 -- said he hoped other victims would come forward.
"It doesn't matter how late it is -- it definitely helps," he said.
"The Ryan Report made it easier to come forward. The legal system was more open."
He said he had absolutely no sympathy for Dunne entering prison as an 82-year-old man.
"It is good enough [for him], I have had this for years.
"We have been in prison in our own way. We keep secrets and try not to tell anybody.
"My life has been very difficult. It is hard to be normal in certain circumstances and there are strange reactions in normal situations," he said.