What the registry entry says
The ClinicalTrials.gov record NCT07097688, last updated in July 2025, registers a Phase 1/2 trial of sodium hexametaphosphate (SHMP), an inorganic polyphosphate, as a regenerative endodontic treatment for necrotic immature permanent anterior teeth in children aged 7 to 11. The trial is randomized 1:1 and parallel, with the investigator masked and allocation concealed in sealed envelopes prepared by a neutral provider. It plans 60 teeth, 30 per arm, with a power calculation of 27 per arm as the minimum. The comparison arm is mineral trioxide aggregate (MTA), the standard material for this procedure; the record types that arm as “no intervention,” a data-entry quirk, since MTA is the active control, not the absence of treatment.
The primary outcomes are clinical and radiographic at one year: normal percussion, palpation, and probing depths with a positive pulp test response, and the absence of pain, mobility, or a periapical lesion. The brief summary frames the study as an 18-month randomized trial. The record lists an actual start date of 29 June 2025 and a status of active, not recruiting, at a single site, the Faculty of Dentistry in Minya, Egypt. The sponsor of record is the individual investigator, with Minia University as the organization.
The animal study behind it
The registered rationale is a same-group dog study published in BMC Oral Health in 2025 (doi:10.1186/s12903-024-05297-0). In a split-mouth model of 36 immature premolars across three dogs, direct pulp capping with SHMP produced significantly thicker predentin and odontoblast layers than MTA (P<0.0001), more fully calcified dentin bridges with regularly arranged dentinal tubules (P<0.05), and a greater increase in root length (P<0.05). That is a three-dog, tooth-level histology result: evidence that SHMP can support dentin bridge formation and continued root development in one animal model, not evidence of pulp regeneration in children.
The wider polyphosphate literature is consistent but modest. Kawazoe et al. reported in 2008 that polyphosphate activates FGF signaling and induces differentiation of human dental pulp mesenchymal stem cells (doi:10.7150/ijbs.4.37), and calcium polyphosphate particles have been shown to reseal and remineralize dentin defects in vitro (Dental Materials, 2019, doi:10.1016/j.dental.2018.11.014). One caution: a cluster of 2015 papers linking polyphosphate to MMP-3-driven odontoblast differentiation was later retracted (retraction of doi:10.1016/j.yexcr.2015.01.007, 2021, with two companion papers in Bioscience Trends). The credible chain today is the dog study plus the FGF-signaling work, not the retracted cell-culture claims.
Where the record is thin
The estimated primary completion date was 1 December 2025 and the estimated study completion date was 1 April 2026. Both have passed. The record has not been updated since July 2025 and no results have been posted, so as of this writing the registry cannot say whether the trial enrolled its planned 60 teeth, ran to completion, or stopped. Estimated dates slip for many academic trials, and a single-investigator sponsor with no posted protocol or statistical analysis plan leaves the analysis plan unknowable from the record. The one-year primary endpoint timing also means that even a completed trial would have readouts lagging completion by design.
Where we differ from the coverage
No press coverage of this trial exists to correct; registry aggregators repeat the entry as filed. The risk here is preemptive. SHMP is a decades-old industrial and food polyphosphate that already appears in toothpastes as an anti-calculus and desensitizing ingredient, and a story combining “chemical already in toothpaste” with “tooth regeneration” is easy to inflate into “a cheap chemical regrows teeth.” The record supports something narrower: a 60-tooth trial testing whether a polyphosphate material promotes dentin bridge formation and root maturation in regenerative endodontics, against the standard of care. That is pulp and dentin repair in immature teeth, not third dentition and not whole-tooth regeneration.
What would move this route
Two postings would change the picture: results on the registry record, read together with the statistical plan they were analyzed under; or an updated record confirming enrollment, completion, and the final analysis population. Until one of those appears, the honest summary for the current pass is that a registered, randomized SHMP-versus-MTA trial exists, its animal basis is one three-dog study, and its own estimated completion dates have passed in silence.
Provenance: every claim above traces to the ClinicalTrials.gov record NCT07097688, the BMC Oral Health dog study, or the cited polyphosphate literature, per our method at /method/.