TABLE 1.

Characteristics of the studies that met inclusion criteria

Samples												Endodontic treatment
Author/year	Country	Types of study	Size	Sample size of necrotic teeth		Gender	Tooth type	Sistemic disease	Preoperative pain	Preoperative medication	Pulp Diagnosis	Instrumentation	Foraminal enlargement	Surgical diameter	Concentration of substance		Number of sessions	Intracanal medication	Sealing technique	Type of cement	Crown sealing
				NaOCl	CHX										NaOCl	CHX
Zarei et al./2006 (27)	Iran	In vivo study	50	25	25	MD	Single canal	Absent	With no sign or symptom	Analgesic or antibiotic two weeks before the study	Necrotic teeth	Rotatory (Easy-race)	No	MD	2.5%	0.2%	Single	No medication	Lateral condensation technique	AH 26 sealer	Cavit temporary restoration
Bashetty et al./2012 (25)	India	Randomized clinical trial	40	20	20	MD	Mandibular first Premolars	MD	No preoperative pain	No medication preoperative	Irreversible pulpitis,necrosed pulp and nonvital teeth exhibiting acute apical periodontitis	Rotatory (Profile series)	No	Size 30	5.25%	2%	Two visits	No medication	MD	MD	Cavit temporary restoration
Almeida et al./2012 (28)	Brazil	Prospective,randomized clinical trial	126	63	63	80 women and 46 men	Single and multiple canals	Absent	No preoperative pain	Antibiotics,anti-inflammatories or analgesics for at least 1 week before the study treatment	Chronic apical periodontitis and necrotic pulp	Rotatory (ProTaper Universal)Hand files	No	F3 (size 30) Size 25, 30 or 35 Flexofile,depending on the anatomy of the canal.	5.25%	2%CHX+ normal salin	Single	No medication	Vertical condensation technique (System B)and Obtura II system	Pulp Canal Sealer EWT	Z-250 resin composite
da Silva et al./2015 (26)	Brazil	Prospective,randomized clinical trial	62	31	31	23 men and 39 woman	Single Canal	Absent	No preoperative pain	None of the patients was taking any medication that could alter his/her perception of pain	Asymptomatic necrotic teethand evidence of apical periodontitis	Reciprocating (Reciproc 40)	Yes	R40 (Size 40/0.06 taper)	5.25%	2% CHX +0.9% saline solution	Single	No medication	Vertical compaction with the continuous -wave technique	AH Plussealer	MD
Bourreau et al.2015 (29)	Brazil	Prospective,randomized clinical study	301	100		MD	Single and multiple canals	MD	Yes/no preoperative pain	MD	Vital tooth; Non vital tooth;Retreatment	Rotatory (Mtwo)	Yes	Mtwo 25/.06	5.25%	2%	Single	No medication	De Deus obturation technique; thermoplasticization and vertical compaction	Pulp Canal Sealer EWT	Coltosol and composite resin or glass fiber post cementation,as required

MD: Missing data, NaOCL: Sodium hypochlorite, CHX: Chlorhexidine