A total of 146 studies were initially identified through searches of multiple databases, including 34 from PubMed/MEDLINE, 36 from Scopus, 36 from Embase, 18 from Web of Science, 21 from the Cochrane Library, and one study was identified through manual searching. After removing duplicates, 117 studies remained for title and abstract screening. Of these, 18 articles were selected for full-text eligibility assessment. Following the full-text screening, two studies were excluded for not meeting the eligibility criteria. Thus, a total of 16 studies met the eligibility criteria and were included in the final review [14, 18, 19, 26,27,28,29,30,31,32,33,34,35,36,37,38] (Fig. 2). The inter-rater agreement among investigators for study inclusion was excellent, with a kappa coefficient of 0.92 across all databases.

PRISMA flow diagram illustrating the study selection process

Table 1 presents the general characteristics of the studies eligible in this systematic review. Published between 2014 and 2025, the selected articles comprised 12 randomized clinical trials [14, 18, 19, 26,27,28,29,30,31,32,33,34] and 4 controlled clinical trials [35,36,37,38]. The included articles originated from various countries, including Egypt [18, 26, 27, 32, 34,35,36,37,38], India [19, 29,30,31], Iran [28, 33], and Pakistan [14]. In total, the studies involved 972 participants, including 12 studies evaluating pediatric populations aged 3 to 13 years with a mean age of approximately 6.69 years [14, 18, 26,27,28, 30, 32,33,34,35,36,37,38], and 4 studies involving adult participants, with a mean age of approximately 35.71 years [19, 29, 31].

Regarding the use of garlic in endodontic treatment, most studies assessed its application as an intracanal medicament in pulpotomy [14, 26,27,28, 30, 33,34,35,36,37,38] or pulpectomy procedures [18, 19], while others investigated its use as an irrigant during biomechanical preparation for pulpectomy [29, 31, 32]. Among the included studies, three assessed the presence of periradicular lesions in the evaluated cases [18, 19, 31]. Regarding root morphology, 12 studies involved multirooted teeth [14, 26,27,28, 30,31,32,33,34, 36,37,38], two studies involved single-rooted teeth [18, 29], and two studies involved both root morphologies [19, 31].

The treatments used as controls in studies investigating intracanal medicaments included formocresol [14, 30, 33,34,35,36,37,38], mineral trioxide aggregate (MTA) [26,27,28], and calcium hydroxide (Ca(OH)₂) [18, 19]. The conventional treatment used as a control in studies on intracanal irrigation was sodium hypochlorite (NaOCl) [29,