This paper presents an efficient protection scheme to provide differentiated survivability services for dynamic traffic in mesh WDM optical networks. In the deterministic Quality of Protection (QoP) framework, connections with different reliability requirements are classified by assigning a continuous spectrum of QoP grades. The backup bandwidth of those connections with low QoP grades is treated as low-speed traffic and may be multiplexed into one backup lighpath for the purpose of efficient bandwidth utilization. In this way, the bandwidth can be efficiently allocated by two-level backup bandwidth aggregation: backup bandwidth sharing and backup bandwidth multiplexing. To allocate the connections with different QoP grades, we propose two efficient routing algorithms: minimum delay QoP routing (MDQR) and maximum aggregation QoP routing (MAQR). Through simulation experiments, we demonstrate that our algorithms work well in terms of blocking performance and the ability of providing differentiated survivability services.