Imagine a five-year-old child sitting in a dental chair with a primary tooth that has decayed all the way to the root. The dental pulp has died, and anaerobic bacteria are multiplying in the darkness of the tiny root canal. The question is no longer whether the tooth should be extracted, but rather which medication can most effectively eliminate the microorganisms hiding inside.
A study from the Department of Pediatric Dentistry, Faculty of Dentistry, Universitas Gadjah Mada, addressed this question in an unexpected way: garlic filtrate, rather than calcium hydroxide, which has traditionally been relied upon, demonstrated larger inhibition zones against clinical bacterial isolates from necrotic primary teeth.
Bacteria Hidden Inside a Decayed Tooth
Published in the International Journal of Human and Health Sciences (Vol. 04 No. 04, October 2020), the study involved 26 children aged 4–7 years who visited the Pediatric Dentistry Clinic at Prof. Soedomo Dental Hospital, UGM, Yogyakarta. All of the children were scheduled to undergo endodontic treatment and had been diagnosed with pulp necrosis.
From aerobic and anaerobic bacterial samples collected directly from their root canals, the researchers identified three major clinical bacterial isolates: Prevotella bivia, Clostridium innocum, and Serratia marcescens. Two reference bacteria were also included: Streptococcus mutans ATCC35688 and Clostridium perfringens.
Identification and isolation were performed based on the CLSI Standardized Method 2012 and Biochemical Identification by Thermo Scientific RapID Systems 2010. All research protocols received approval from the Ethics and Advocacy Committee of FKG UGM.
The research team was led by IAIA Krisna Kencana Dewi, a postgraduate student at FKG UGM, together with Dr. drg. Indra Bramanti, M.Sc., Sp.KGA(K), a lecturer in the Department of Pediatric Dentistry, FKG UGM, who also served as the corresponding author.
When Garlic Outperforms Conventional Medication
Antibacterial activity was tested using the diffusion method. Calcium hydroxide was compared with garlic extract from the “Tawangmangu Baru” variety at concentrations of 20%, 40%, 60%, and 80%, as well as garlic filtrate obtained by crushing the garlic and filtering it through sterile gauze.
The results were striking.
Against Prevotella bivia, calcium hydroxide produced an inhibition zone 30 mm in diameter, while garlic filtrate reached 49 mm. Against Clostridium perfringens, calcium hydroxide produced a 34-mm inhibition zone, whereas garlic filtrate again performed better at 46 mm. Even against Serratia marcescens, garlic filtrate produced a 31.5-mm inhibition zone compared with 23 mm for calcium hydroxide.
An even more surprising finding involved Clostridium innocum. Calcium hydroxide produced no inhibition zone at all (0 mm), whereas garlic filtrate produced an inhibition zone of 28 mm.
Garlic extract prepared using ethanol at various concentrations, however, produced considerably weaker results. At concentrations of 20%–60%, the inhibition zones against nearly all bacteria were zero. Only the 80% extract showed activity against Serratia marcescens, and even then, the inhibition zone measured only 10 mm.
“Calcium hydroxide has a greater inhibitory effect than garlic extract, but a lower effect than garlic filtrate.”
This was the conclusion reported by the research team, including Dr. drg. Indra Bramanti, M.Sc., Sp.KGA(K).
Allicin and a Mechanism That Remains Poorly Understood
Calcium hydroxide works by releasing hydroxyl ions, creating a highly alkaline environment (approximately pH 12.5). This condition damages bacterial cell membranes, denatures proteins, and damages microbial DNA. This mechanism has long been recognized and is one of the primary reasons calcium hydroxide has been widely used as a root canal medication.
Garlic, however, contains a different weapon. Allicin, its primary active compound, is believed to be effective against both Gram-positive and Gram-negative bacteria. Processing garlic into a filtrate appears to preserve allicin more effectively than the ethanol maceration process used to produce the extract. During extraction, some active components may be lost or reduced, which could explain why the filtrate demonstrated superior antibacterial activity.
Nevertheless, the researchers acknowledged that the precise mechanism by which allicin acts against bacteria in primary tooth root canals requires further investigation. Which components play the most important role, and how should the formulation be optimized for clinical application? These questions remain unanswered.
From the Laboratory to the Pediatric Dental Chair
These findings do not mean that calcium hydroxide will be replaced immediately. Its clinical safety and long-standing track record in endodontics remain important considerations. However, the study opens a relevant area of discussion: herbal materials such as garlic, particularly in filtrate form, may have potential as alternatives or adjuncts to root canal medications, especially in cases where calcium hydroxide fails to provide adequate antibacterial activity.
In Indonesia, where 93% of children aged 5–6 years were reported to have dental caries according to the 2018 Basic Health Research (Riskesdas), and many cases remain untreated until they progress to pulp necrosis, the search for effective, affordable, and accessible medications is not merely an academic concern. It is a matter of addressing the oral health of millions of children who grow up with pain that could have been prevented.
Garlic is found in the kitchens of nearly every Indonesian household. The remaining question is: how much longer will it take before it finds its way into the pediatric dental clinic?
Source DOI: http://dx.doi.org/10.31344/ijhhs.v4i4.214
Authors: Nanda Ayu, drg. Achmad Zam Zam Aghasy, M.Kes.
Photo: Pexels