What was tested

Weiss, Trevizani, Carvalho, and colleagues at the Universidade Federal de Juiz de Fora and Universidade Federal do Espírito Santo report a method for producing decellularized extracellular matrix (ECM) scaffolds from swine dental pulp, comparing fully formed erupted first molars (M1) with developing intraosseous second molars (M2) (Weiss et al. 2026). The work is an experimental in vitro study using coronal pulp from molars collected as a slaughterhouse by-product; no live-animal experimentation was performed. Pulps from 13 pigs (12.5 heads) were used; M2 pulps were taken from the maxilla only because the surrounding bone is softer there. The decellularization protocol used 0.1% EDTA with 10 mM Tris for 2 hours, followed by overnight 0.1% SDS with 10 mM Tris, and was deliberately free of enzymes, nucleases, and Triton X-100 (Weiss et al. 2026, Methods).

DNA removal and collagen preservation

DNA quantification (n=3 per group) showed effective cell removal in both pulp types. Native M1 pulp contained 102.95 ng DNA per milligram dry weight, which fell to 7.56 ng/mg after decellularization; native M2 contained 302.76 ng/mg, falling to 9.64 ng/mg. These correspond to reductions of 92.7% for M1 and 96.8% for M2 (one-way ANOVA with Tukey post-hoc, p<0.0001). Residual DNA levels did not differ between the two decellularized groups (p=0.60) (Weiss et al. 2026, Results).

Collagen content, measured by hydroxyproline assay (n=3), was 9.25 µg/mg in native M1, 21.45 µg/mg in decellularized M1, 22.24 µg/mg in native M2, and 22.15 µg/mg in decellularized M2. The overall ANOVA reached p=0.050, and the authors report that Tukey’s post-hoc test found no statistically significant differences among groups. They treat the apparent increase in M1 collagen after decellularization as a trend attributable to enrichment of the collagenous fraction after cellular removal, not to new collagen synthesis (Weiss et al. 2026, Results).

Yield and structural differences between developmental stages

The developing M2 pulps were substantially larger. Mean weight per pulp was 1.173 g for M2 versus 0.377 g for M1, an increase of about 211% (Table 1). Computed tomography confirmed that M2 teeth are larger than M1 in mesiodistal and buccopalatal dimensions despite incomplete crown formation (Weiss et al. 2026, Results).

Histology revealed a developmental contrast in vasculature. Native M1 pulp contained distinct blood vessels lined by endothelial cells, whereas native M2 pulp showed immature vascular structures that were still forming and not lined by endothelial cells. After decellularization, nuclei were absent in both groups by H&E, Masson’s trichrome, and DAPI staining, and the tissue network appeared better preserved in M2 (Weiss et al. 2026, Results).

Scanning electron microscopy (n=8 total: two native and two decellularized pulps per group) showed porous scaffolds in both decellularized groups. Crystalline structures suggestive of intrinsic mineralization were present in native M2, and mineralized deposits were observed exclusively in decellularized M2, absent in decellularized M1 (Weiss et al. 2026, Results, Figure 5).

What it means for the pulp-dentin repair route

For the pulp-dentin repair program, the paper is a scaffold-preparation study rather than a clinical outcome. Its practical point is that developmental stage matters when choosing a pulp-derived ECM source. Developing M2 pulp gives more material per tooth and retains mineralization signals after decellularization, which could be relevant if the goal is to build a scaffold for dentin-pulp interface repair. The authors note that the mature vascular organization of M1 might instead favor diffusion of recellularizing solutions and angiogenesis, although that remains a hypothesis requiring functional assays (Weiss et al. 2026, Discussion).

What it does not show

The study does not test recellularization, cell adhesion, odontogenic differentiation, or any in vivo implantation. The collagen and porosity findings did not reach statistical significance, and the sample sizes were small (n=3 for biochemical quantification). M2 pulps came from the maxilla only, so possible jaw-specific differences in pulp volume or composition were not assessed. The mineralized deposits in M2 were identified by morphology, not elemental analysis such as energy-dispersive X-ray spectroscopy. The work is in porcine by-product tissue, not human pulp, and any clinical scaffold would require immunogenicity, sterilization, and consistency testing.

Where we differ from the coverage

We found no popular or press coverage of this paper. The result should not be read as “scientists grew new pulp” or as a ready-made regenerative endodontic material. It is a characterization of a decellularization protocol and a comparison of two developmental stages, with the honest next steps being recellularization studies, larger sample sizes, and functional repair assays.

Provenance: grounded in the open-access full text of Weiss et al. 2026, Revista Eletrônica Acervo Saúde 26(8):e25080, DOI 10.25248/reas.e25080.2026. Method and sourcing standard at /method/.