When a will, trust agreement or other instrument establishing a trust fails to provide for the contingency of the trustee‘s refusal to accept the trust or the trustee‘s resignation, death or incapacity, the Probate Court specified in section 45a-499p may, on the happening of any such contingency, appoint some suitable person to fill such vacancy, taking from such suitable person a probate bond, unless in the case of a will it is otherwise provided therein. The court may appoint a successor trustee of an inter vivos trust before such contingency has occurred if the court finds that a vacancy in the office of trustee is likely to occur. The court shall specify the conditions that the successor trustee of such inter vivos trust must satisfy before becoming trustee. In the event of a vacancy in the office of trustee of such inter vivos trust, the successor trustee may assume the office immediately upon satisfying the conditions set forth in the court’s order without further court action.