Emdogain

The periodontal defects refinement and regenerative procedures were performed 1 month after re-establishing oral hygiene. Following general and local anesthesia, the full-thickness gingival flaps were raised, and the granulation tissue was removed using scalers. Each defect was refined and standardized using a piezotome (Piezosurgery, Mectron, Carasco, Italy) to an approximate volume of 60 mm³, with a dimension of 3 × 4 × 5 mm³ (mesiodistal length × depth × buccal-lingual width). The root surfaces of the experimental teeth were debrided, and the defects were rinsed with sterile saline (B Braun, Penang, Malaysia) and dried with sterile gauze. Each defect was then implanted with one of the following: (a) CollaPlug alone (Col), (b) CollaPlug + HS low (HS3 at 36 µg), (c) CollaPlug + HS high (HS3 at 180 µg), and (d) Emdogain (Emdo). Emdogain (Straumann, Basel, Switzerland) was administrated as a gel via a syringe and needle provided by the manufacturer. The Collaplug scaffolds were slightly compressed to fit snuggly into the defect. After implantation, the defects were closed using resorbable sutures (Vicryl 5–0, Ethicon, Bridgewater, NJ, USA) (Fig. 1d). After surgery, antibiotics and analgesics were given as described above, and the animals were closely monitored. Soft food was given for a week postoperatively to facilitate healing.

After receiving approval for this animal study from the University of Bonn and the local authorities (Landesamt für Natur, Umwelt und Verbraucherschutz Nordrhein-Westfalen; AZ 85-51.04.2010.A394), four-week-old Wistar rats were obtained from the Charles River Laboratories (Sulzfeld, Germany). All animals were kept in the animal facility of the University of Bonn according to institutionally approved protocols. All applicable international, national, and/or institutional guidelines for the care and use of animals have been followed. Per group, five animals (15 animals in total) were maintained under stable environmental conditions at a room temperature of 21 °C and humidity of 35% under a 12 h day–night cycle. All groups of animals were provided with water and food (sniff, Soest, Germany) ad libitum. Each animal group underwent a different experimental treatment: (1) normal occlusion with an untreated fenestration defect, (2) occlusal hypofunction with an untreated fenestration defect, and (3) occlusal hypofunction with a fenestration defect treated with EMD (Emdogain^®, Straumann, Basel, Switzerland).

Microsurgical approaches, adapted to the treatment algorithm by Cortellini and Tonetti (2015), were applied to access the defects. A bone substitute (DBBMc, Bio Oss^® Collagen; Geistlich, Wolhusen, Switzerland) was used to fill the defect and to prevent a soft tissue collapse. In non-contained defects, a collagen membrane (Bio Gide^®Perio; Geistlich, Wolhusen, Switzerland) was applied. An enamel matrix derivative (EMD, Emdogain^®; Straumann, Basel, Switzerland) was used for contained defects. Suturing was accomplished with non-resorbable 6-0 and 7-0 monofilament material (e-PTFE, W. L. Gore & Associates, Flagstaff, AZ, USA) by internal offset vertical mattress sutures, interrupted single sutures, double sling sutures, or a combination of these for achieving primary closure.

Clinical measurements were obtained at baseline. Full-thickness mucoperiosteal flaps were elevated on the buccal, lingual and interproximal aspects of the involved teeth. Granulation tissue adherent to the alveolar bone was removed. Remaining subgingival calculus was removed with curettes. Following open flap debridement, teeth were randomly assigned to receive either the test or the control treatment by the tossing of a coin. In the test sites, EMD in propylene glycol alginate (Emdogain; Straumann, Basel, Switzerland) was directly applied to the exposed alveolar bone as well as onto the root surfaces. Flaps were repositioned and tension-free primary closure of the wound was achieved by means of single non-resorbable sutures (Propylen 5.0; Medipac, Kilkis, Greece). Control sites received the same surgical procedure but without the application of Emdogain. Sutures were removed after 14 days. Patients were advised to rinse twice daily with a 0.2% solution of chlorhexidine digluconate (Corsodyl; GlaxoSmithKline, Münchenbuchsee, Germany) for 2 weeks. No antibiotics were given48 (link)49 (link), and mechanical oral hygiene was not allowed in the surgical areas during this period. Analgesics were taken by the patients on an as needed basis.

GX powder was formed from a mixture of Gellan (P8169, Phytagel™, Sigma Aldrich, Saint-Quentin-Fallavier, France) and Xanthan powders (G1253, Sigma Aldrich, France) at a ratio of 9:1 wt%. All the hydrogels were prepared from this mixture with cold PBS: Phosphate-Buffered Saline (14190144: Thermo Fisher Scientific, Illkirch-Graffenstaden, France) buffer solution; a 30 s vibration using the vibrator Softly Satelec (Henry Schein, Limonest, France) was then applied to enable the hydrogel crosslinking. Several gel densities were tested and the GX hydrogel at the density of 3% was selected to be used in this study due to its mechanical properties and comparable clinical handling to the commercial Emdogain^® (EMD: Straumann, Basel, Switzerland). The ADP-5 peptide was incorporated (mixed with the GX powders directly) in the selected GX hydrogel at the concentrations of 100 and 200 µg/mL. The GX/ADP-5 mixture was first prepared using PBS, and then immerged in the culture media before the cell contact.
The list of tested samples used in the first and the second investigation steps, including synthetic peptide, and experimental and commercial gels, are shown in Table 1. The first investigation refers to the assessment of ADP-5 peptide alone and the second investigation refers to the assessment of ADP-5 factionalized experimental GX hydrogel.

Four-week-old Wistar rats were obtained from Charles River Laboratories (Sulzfeld, Germany) and maintained in the University of Bonn animal facility according to institutionally approved protocols. Approval for the animal study was obtained from the University of Bonn and local authorities (Landesamt für Natur, Umwelt und Verbraucherschutz Nordrhein-Westfalen; Az 87-51.04.2010.A394). All applicable international, national and/or institutional guidelines for the care and use of animals were followed. A total of 15 animals (n = 5/group) were housed under stable environmental conditions at a room temperature of 21 °C and humidity of 35% on a 12-h day-night cycle. All animals received water and food ad libitum. The animals were divided into the following experimental groups: (1) control animals, (2) animals fed HFSD (sniff, Soest, Germany) and (3) animals whose defects were treated with EMD (Emdogain^®, Straumann, Basel, Switzerland) and fed HFSD.