Biological dentistry covers treatments with varying levels of evidence behind them. Metal-free fillings are ordinary restorative dentistry. Ceramic implants have clinical guideline recognition. Cavitation surgery has no professional body endorsement, though the research on the underlying condition has moved recently. The table below sets each treatment against its conventional equivalent.
Treatment comparison
| Treatment | Conventional equivalent | What the evidence shows | Mainstream position |
| Metal-free fillings and crowns | Amalgam fillings | Composite and ceramic are established restorative materials. Amalgam is being phased out on environmental grounds, not toxicological ones. | Uncontested. The EU banned amalgam from January 2025 and a global phase-out is agreed for 2034. |
| Ceramic (zirconia) implants | Titanium implants | Five-year survival of 97.2%, comparable to titanium. Evidence applies mainly to one-piece designs; two-piece systems have limited long-term data. No evidence zirconia outperforms titanium on peri-implantitis. | Guideline-recognised. Germany has had an S3 guideline since October 2022, framed on material behaviour rather than systemic health. |
| Protected amalgam removal | Standard removal | Drilling out an old filling volatilises mercury vapour, frequently above safety thresholds for more than an hour afterwards. The bundled IAOMT protocol itself has never been evaluated by any professional body. | Split. Protection during necessary removal is well founded. Elective removal of intact fillings to treat illness is advised against. |
| Extraction plus immediate ceramic implant | Root canal treatment | No evidence links successfully root-treated teeth to systemic disease. Research interest is in untreated apical infection — the disease, not the treatment. | Against. The AAE finds no valid scientific evidence for the systemic claim. |
| Cavitation surgery | No equivalent; conventionally not treated | A 2022 systematic review of 29 studies reported pain remission of 66–100% after surgical curettage, with up to a third showing minimal improvement or recurrence, and found no gold-standard diagnostic method. A 2025 molecular study found affected bone has a different gene expression profile from healthy controls, on a sample of three against three. | Not endorsed. The AAE will not condone it and insurers classify it as experimental. A 2025 academic scoping review recommends imaging plus surgical intervention. |
| Platelet-rich fibrin (PRF) | Unassisted healing | A randomised split-mouth trial in November 2025 found PRF alone did not prevent socket residue, and recommended combining it with bone substitute material. | Accepted as an adjunct. The specific claim that it removes the need for grafting material is not supported. |
| Titanium sensitivity testing | Standard patch testing | No validated test exists. Results are wildly discordant — one study found 37.5% positive on one method and 0% on another in the same patients. | Not established. The mechanism appears innate rather than allergic, which undercuts both the dismissal and the commercial testing model. |
Materials: fillings, crowns and implants
The argument here is materials science rather than contested physiology. The EU banned dental amalgam from January 2025 and a global phase-out is agreed for 2034, so metal-free restoration is simply where dentistry is going. On implants, the International Team for Implantology’s 2023 consensus puts zirconia five-year survival at 97.2%, and Germany has had an S3 guideline covering ceramic implants since October 2022.
The guideline sets two limits. The evidence applies mainly to one-piece designs, with two-piece systems recommended only under study conditions. And there is no clinical evidence that zirconia outperforms titanium at preventing peri-implantitis.
Amalgam removal
Amalgam removal divides cleanly into two questions that are often run together. Removing a filling that needs replacing anyway, with protection, is well founded: high-speed drilling volatilises mercury vapour frequently above safety thresholds for more than an hour afterwards, according to a mainstream occupational health journal. Removing intact, sound fillings to treat illness elsewhere is a different proposition. The FDA advises against it and the ADA’s Code of Ethics calls it improper and unethical in non-allergic patients where the dentist alone has recommended it.
On the named removal protocol: it has never been evaluated by the ADA, the FDA or any UK body, positively or negatively. Its individual components — rubber dam, high-volume evacuation, sectioning rather than drilling out, external suction — are standard uncontroversial practice.
Cavitation surgery and root canal replacement
Cavitation surgery is the treatment on which biological dentistry and conventional dentistry are furthest apart. The American Association of Endodontists will not condone surgical intervention for suspected lesions of this type, and Aetna classifies the procedure along with its bone grafting and detection imaging as experimental, investigational or unproven.
The research has moved in the past two years, and mostly through one collaboration between Professor Shahram Ghanaati at Goethe University Frankfurt and Johann Lechner, the Munich clinician who has documented the condition for four decades. A molecular study published in May 2025 compared affected jawbone against healthy controls and found a different gene expression profile, with CCL5/RANTES, VEGF and IGF upregulated and collagen types I, II and IV downregulated. The sample was three cases against three controls, age and sex were not accounted for, and the authors call for replication. Separately, a 2025 scoping review from a conventional academic group in Poland treats the condition as a real entity characterised by silent inflammation and recommends advanced imaging together with surgical intervention.
The largest systematic review to date screened 4,051 articles and included 29. Pain remission after surgical curettage ranged from 66% to 100%, with up to a third of patients showing minimal improvement or recurrence. No gold-standard diagnostic method could be identified, every included study was observational with a high risk of bias, and the authors called for prospective trials.
Replacing a root-treated tooth with an implant on systemic grounds is a separate question. The AAE finds no valid scientific evidence linking root canal treatment to systemic disease, and where research interest has revived it concerns untreated apical infection — the disease rather than the treatment.
The adjuncts
Platelet-rich fibrin, drawn from the patient’s own blood, is accepted as a healing adjunct. A randomised split-mouth trial published in November 2025 found that PRF alone did not prevent socket residue after third molar extraction, and recommended combining it with bone substitute material — the opposite of the position that adequate systemic preparation removes the need for grafting.
On titanium sensitivity testing, a 2022 review of the available diagnostics concluded that no validated test exists. Results are discordant, with one study finding 37.5% of patients positive on one method and none of the same patients positive on another, and the authors argue the mechanism is innate rather than allergic. That cuts against the position that titanium sensitivity is not a real phenomenon, and against the reliability of any test currently sold for it.
What this means when choosing a clinic
The answer to whether biological dentistry is evidence-based differs by treatment, which is why the question is worth asking treatment by treatment. Ceramic implants and metal-free restoration have guideline recognition. Elective removal of intact fillings and cavitation surgery currently do not. A clinic may offer both and describe them in the same terms. Our guide to what biological dentistry is covers the underlying claims in more detail, and we have looked separately at Dr Dominik Nischwitz, the field’s most prominent advocate.
