Phosphopullulan-based pulp-capping material stimulates reparative dentin formation.

Objectives: To evaluate the inflammatory reaction and reparative dentin formation of a recently developed phosphopullulan-based (PPL) hydraulic calcium-silicate cement (hCSC) employed for pulp capping. Any discoloration of the hard dental tissues due to the material was also evaluated. Methods: After approval by the KU Leuven Ethical Commission for Animal Research, 44 permanent teeth from 3 minipigs (33-36 months old) were included in this study. The teeth were allocated to 2 time periods (7 and 70 days) and 2 different materials: experimental PPL-based hCSC (n=28) and Biodentine (Septodont; n=16), the latter serving as a commercially available control material. Briefly, after anesthesia at day 1, the teeth on?at the left side of the animals were ultrasonically cleaned, polished and finally disinfected using 10% iodine povidone. A 1-mm pulp exposure was immediately prepared with a sterile bur under copious saline water irrigation following the ISO 7045-2008 standard. After the bleeding was controlled, the pulp-capping materials were applied and the cavity closed using a glass-ionomer (Fuji II, GC) with a composite (G-aenial Posterior, GC) bonded (G-Premio Bond, GC) on top. Sixty-three days after the first procedure, the same operative treatment was carried out at the other side of the animals. On day 70, tooth discoloration was examined visually by two independent researchers. After perfusion under terminal anesthesia the teeth were harvested and fixed in 4% formaldehyde for 2 weeks. Micro-CT analysis (SkyScan 1172, Bruker) was performed and the degree of soft-tissue inflammation and mineralized tissue formation assessed histologically. Results: No significant difference in inflammation degree and mineralized tissue formation was observed for both hCSCs (p≥0.05). However, Biodentine induced significantly less tooth discoloration than the experimental hCSC containing PPL (p<0.05). Conclusions: The PPL-based hCSC was able to generate reparative dentin at a similar extent as the commercially available reference hCSC. Student Presenter This abstract is based on research that was funded entirely or partially by an outside source: FWO - Research Foundation Flanders (11B4318N) Disclosure Statement: The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONEstatus: Published onlin

Freshly-mixed and setting calcium-silicate cements stimulate human dental pulp cells

OBJECTIVES: To evaluate the effect of the eluates from 3 freshly-mixed and setting hydraulic calcium-silicate cements (hCSCs) on human dental pulp cells (HDPCs) and to examine the effect of a newly developed hCSC containing phosphopullulan (PPL) on HDPCs. METHODS: Human dental pulp cells, previously characterized as mesenchymal stem cells, were used. To collect the eluates, disks occupying the whole surface of a 12-well plate were prepared using an experimental hCSC containing phosphopullulan (GC), Nex-Cem MTA (GC), Biodentine (Septodont) or a zinc-oxide (ZnO) eugenol cement (material-related negative control). Immediately after preparing the disks (non-set), 3ml of Dulbecco's Modified Eagle Medium (DMEM) with 10% fetal bovine serum (FBS) were added. The medium was left in contact with the disks for 24h before being collected. Four different dilutions were prepared (100%, 50%, 25% and 10%) and cell-cytotoxicity, cell-proliferation, cell-migration and odontogenic differentiation were tested. The cell-cytotoxicity and cell-proliferation assays were performed by XTT-colorimetric assay at different time points. The cell-migration ability was tested with the wound-healing assay and the odontogenic differentiation capacity of hCSCs on HDPCs was tested with RT-PCR. RESULTS: Considering all experimental data together, the eluates from 3 freshly-mixed and setting hCSCs appeared not cytotoxic toward HDPCs. Moreover, all three cements stimulated proliferation, migration and odontogenic differentiation of HDPCs. SIGNIFICANCE: The use of freshly-mixed and setting hCSCs is an appropriate approach to test the effect of the materials on human dental pulp cells. The experimental material containing PPL is non-cytotoxic and positively stimulates HDPCs.status: publishe

Titanium implant functionalization with phosphate-containing polymers may favor in vivo osseointegration

Aim: Osseointegration of titanium implants is predictable, but can be improved via surface functionalization. Materials and Methods: 120 implants were installed in parietal bone of 12 domestic pigs and left to heal for 1 or 3 months. Five groups were defined according surface treatments: immersion in water (H2O), 10% polyphosphoric acid (PPA10), 1% phosphorylated pullulan (PPL1), 10% phosphorylated pullulan (PPL10), or 10% phosphorylated pullulan + 1 μg BMP-2 (PPL10 BMP). As primary outcome, implant osseointegration was evaluated by quantitative histology, namely peri-implant bone formation (B/T in %) and bone-to-implant contact (BIC in %) for each healing period. The Wilcoxon signed-rank test and Mann Whitney U-test with α=0.05 were performed. Results: PPL10 and PPA10 groups showed significantly higher B/T and BIC results than the control (H2O) group at 1-month (p0.05). After 3 months, no experimental group showed a significant difference compared to the control group (H2O) for both investigated parameters (B/T and BIC; p>0.05). Conclusion: Functionalizing titanium implants with inorganic or organic phosphatecontaining polymers at 10 wt% concentration may stimulate peri-implant bone formation and implant osseointegration at early healing times.status: publishe