case report_ microsurgery I therapeutic alternative, predictable and viable for the conservation of teeth with secondary or persistent apical periodontites. A new generation of premixed bioceramic products simplifies retrofilling proce- dures and might have elicited quicker and complete apical bone repair._ _References 1. Torabinejad M, Kutsenko D, Machnick TK, Ismail A, Newton CW. Levels of evidence for the outcome of nonsurgical endodontic treatment. J Endod. 2005 Sep;31(9):637-646. 2. Torabinejad M, Corr R, Handysides R, Shabahang S. Outcomes of nonsurgical retreatment and endodontic surgery: a systematic review. J Endod. 2009 Jul;35(7):930-937. 3. Kang M, In Jung H, Song M, Kim SY, Kim HC, Kim E. Outcome of nonsurgical retreatment and endodontic microsurgery: a meta-analysis. Clin Oral Investig. 2015 Apr;19(3):569-582. 4. Curtis DM, VanderWeele RA, Ray JJ, Wealleans JA. 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Int Endod J. 2006 May;39(5):343-356. _about the author roots Dr. Leandro Pereira has a degree from UNICAMP. He is professor of the Depart- ment of Endodontics at São Leopoldo Mandic Univer- sity, Campinas, Brazil. He has a master and doctorate in pharmacology, anesthe- siology and drug therapy at FOP-UNICAMP, and he is a specialist in endodontics, operatory microscopy and inhalation sedation. He is coordinator of the Photography in Dentistry Program of São Leopoldo Mandic University, Belo Horizonte, Brazil; coordinator of the Endodontic Microsur- gery Program at Branemark Osteo Integration Center; and a member of the American Association of Endodontists. roots 1_ 2019 I 11