"We put it back on the shelves the afternoon that the judgement was delivered and it was issued within minutes," said Ms Best.
Currently, three people had reserved the book. The library would buy another copy if it kept receiving a large number of holds.
Ms Best was pleased the book was available to borrowers again.
"From our point of view, we feel that teenagers face these sorts of problems in their lives and it's better that they encounter them first in a safe fictional setting to think about," she said.
According to the Film and Literature Board of Review's most recent decision on Into the River, the board received more than 550 submissions and emails expressing views about the book. The board said it accepted the book described, depicted or otherwise dealt with matters such as sex, crime, cruelty and violence.
It said it had read, considered and discussed all aspects of the book about which submitters had expressed concern.
It accepted there were aspects of the book which many would find offensive and regard as inappropriate for children. However, none of the submissions provided any direct evidence of any harm caused when the book was available on an unrestricted basis or pointed to injury to the public good if the book were again available on an unrestricted basis.
The decision said the book could have a positive impact on the public good if it either encouraged young adults to read, as a number of submitters suggested it might, or raised the real problems surrounding bullying for thought and debate.
The book described unacceptable, offensive and objectionable behaviours, but it didn't in any way promote them.
"On the contrary, the book clearly sets out to discourage and discredit such behaviours," the decision said.