A parulis, or gumboil, is a localized accumulation of pus located with the gingival tissues (Figure 5-25). It originates from either an acute periapical abscess or an occluded periodontal pocket. The cortical bone is destroyed by the inflammatory process, and the gumboil often appears as a yellowish
white bump on the gingiva. The lesion is usually painful, and pain relief occurs when the “boil” ruptures or drains spontaneously. To permanently resolve this problem, the nonvital tooth or periodontal abscess must be treated.