CD40LG and periodontitis: The previous experimental results showed that low concentration of CpG+CD40L (1 uM of CpG+0.1 ug/ml of CD40L) had a higher inhibitory effect on ligature induced periodontitis and alveolar bone loss than that of high concentration of CpG+CD40L (10 uM of CpG+1 ug/ml of CD40L).