Do oil pulling and mercury-free fillings actually help dental health?

The oral microbiome is not just about "killing germs." Like the gut, your mouth depends on a balanced microbial community. Pathogenic bacteria like Streptococcus mutans and Porphyromonas gingivalis thrive when this balance is disrupted, often by sugar, chronic dry mouth, or harsh antiseptic mouthwashes that wipe out beneficial species along with harmful ones⁴.

Mercury amalgam fillings are approximately 50% mercury by weight. Mercury is a potent neurotoxin, and amalgam fillings continuously release low levels of mercury vapor, which increases with chewing, grinding, and hot beverages. In 2020, the FDA issued updated recommendations advising against amalgam fillings for pregnant women, nursing mothers, children under six, and people with kidney impairment or neurological conditions². Many countries in Europe have already restricted or banned their use.

Root canals remain controversial. The focal infection theory, first proposed in the early 1900s and revisited by researchers since, suggests that bacteria can remain trapped inside the microscopic tubules of a dead tooth, potentially contributing to systemic health issues. While mainstream dentistry considers root canals safe, biological and holistic dentists often recommend extraction and biocompatible replacements instead.

Oil pulling — swishing oil (typically coconut or sesame) for 10 to 20 minutes — has been shown in clinical studies to significantly reduce S. mutans counts in plaque and saliva³. It appears to work through a mechanical "pulling" of bacteria and through the lauric acid in coconut oil, which has antimicrobial properties. See our Oil Pulling page for a deeper look.

Tongue scraping removes the bacterial coating on the tongue that contributes to bad breath and can harbor pathogenic organisms. It is a staple of Ayurvedic medicine and takes only seconds each morning.

Biological (holistic) dentistry integrates these concerns — avoiding mercury and fluoride, using biocompatible materials, considering the systemic effects of dental procedures, and treating the mouth as connected to the whole body rather than as an isolated system.

Dewhirst et al. (2010) catalogued the oral microbiome in the Human Oral Microbiome Database (HOMD), which includes 619 taxa in 13 phyla⁵. Their work in the Journal of Bacteriology also analyzed 36,043 16S rRNA gene clones from studies of the oral microbiota: of the 1,179 taxa identified, 24% were named, 8% were cultivated but unnamed, and 68% were uncultivated phylotypes⁵. The oral cavity contains a number of different habitats (the teeth, gingival sulcus, tongue, cheeks, hard and soft palates, and tonsils), with distinct subsets of taxa predominating at each, so the mouth is not a single environment but a collection of distinct ecological niches⁵. In dysbiosis, the finely tuned equilibrium of the oral ecosystem is disrupted, allowing disease-promoting bacteria to cause conditions such as caries, gingivitis and periodontitis⁴.

The FDA's 2020 safety communication on dental amalgam represented a significant regulatory shift. After decades of maintaining that amalgam was safe for all populations, the agency updated its recommendations to specifically warn high-risk groups. The communication acknowledged that mercury vapor is continuously released from amalgam fillings, that this release increases during chewing and grinding, and that certain populations may be more susceptible to adverse health effects. The agency recommended that these groups use non-mercury alternatives such as composite resins and glass ionomer cements whenever possible².

Peedikayil et al. (2016) conducted a randomized controlled trial comparing coconut oil pulling to chlorhexidine mouthwash. Using Dentocult SM Strip mutans tests, they found a statistically significant reduction in S. mutans colony counts in both groups after two weeks, with the oil pulling group showing reductions comparable to the antiseptic mouthwash. The study concluded that coconut oil pulling could be used as an effective adjunct to mechanical oral hygiene measures, offering an antimicrobial benefit without the side effects associated with chlorhexidine, such as tooth staining and altered taste³.

Kilian et al. (2016) published an updated review for oral healthcare professionals in the British Dental Journal, arguing that the traditional "search and destroy" approach to oral bacteria is outdated. They presented evidence that disrupting the commensal microbiome with broad-spectrum antimicrobials can paradoxically increase susceptibility to pathogenic colonization. Their framework proposed that clinical oral care should aim to maintain microbial homeostasis rather than pursue sterility, a paradigm shift with implications for mouthwash use, antibiotic prescribing, and preventive strategies⁴.