The nerves which provide sensation to the breasts travel along the chest wall then up through the breast tissue to the overlying skin. If you had implants on top of the muscle, it is entirely possible that the nerves were close to the contracture scars and may have been removed when the scars were removed. If that was the case, it is unlikely that all the sensation will return. However, there is plenty of cross-over among the sensory nerves and often times some degree of sensation returns over time. If the implants were under the muscle, it is still possible to have some disruption of breast sensation, albeit much less likely.
Regardless, it is common to have some disruption of sensation following breast surgery, particularly with removal of previous implant capsules as you did. It can take many months for sensation to return. Unfortunately, there is not much you can do but allow for time.