Child Dedication is a great step for your family, but it’s certainly not the same thing as salvation. Salvation is what happens when your child decides to start a relationship with God, and baptism is when they decide to go public with their faith.
Child Dedication is less about your child’s choice now and more about setting them up for those choices later. When you dedicate your child, you’re committing to raise them in an environment where they hear about Jesus and have an opportunity to believe in Him. It’s a great practice, but it is optional.