Dentin - Correct. If the enamel under the subgingival plaque is intact then dentin is least likely to be damaged by during periodontal disease. Damage of enamel requires acid formation (plaque containing saccharolytic bacteria) from sugar fermentation. The subgingival plaque contains bacteria that are more hemolytic and proteolytic and not sacchrolytic. Note: subgingival caries does occur and the plaque that causes it contains bacteria that are more saccharolytic.