Conclusion: calcium hydroxide iodoform paste used in root canal disinfection can decrease times of the block therapy on chronic periapical abscess with sinuses.

• 结论：用氢氧化钙碘仿糊剂根管内封药消毒能够减少有窦型慢性根尖周脓肿根管封药消毒的次数，有利于窦道的尽快愈合。