(a) An order of disposition or other adjudication in proceedings under this subchapter shall not be deemed a conviction of crime or impose any civil disabilities ordinarily resulting from a conviction or operate to disqualify the child in any civil services application or appointment.
(b) The disposition given a child and evidence given in any hearing under this chapter shall not be admissible as affirmative evidence against him in any case or proceeding in any other court, whether before or after reaching majority, except in dispositional or sentencing proceedings.