4.3. Periodontal Fenestration-Type Defect Model and Treatment with EMD

A fenestration-type defect was created to investigate the effects of obesity on regenerative bone healing [52]. Animals were anesthetized intraperitoneally with ketamine 10% (75 mg/kg) and medetomidine (0.5 mg/kg). Local anesthesia was performed with articaine 1:200,000 dissolved in saline according to the weight of the animal. The skin on the right side of the jaw was shaved and disinfected with liquid povidone iodine. Using a 15-c scalpel, a 2-cm skin incision was made at the inferior border of the mandible. After cutting the superficial fascia, the underlying masseter muscle and periosteum were separated from the bone to expose the right mandible. After careful dissection with a raspatory, the oral mucosa was identified on the upper wall of the surgically created access chamber without violating the attachment of the intraoral keratinized gingival margin. Bone removal on the buccal aspect of the first molar was performed using a slow-speed rose bur under saline irrigation. A standardized fenestration defect was created with an approximate height and depth of 2 mm and a horizontal dimension of 4 mm (Figure 5c). In order to standardize the dimensions of the defect, this was measured during surgery using a standardized periodontal probe (UNC 15, Hu-Friedy, Frankfurt am Main, Germany). The distance between the upper margin of the bony defect and the crestal bone of the first molar was 1 mm. In addition, the buccal root of the first molar was freed from its periodontal ligament, cementum and superficial dentin. Root debridement was performed with saline followed by conditioning with ethylenediaminetetraacetic acid (EDTA, PrefGel^®, Straumann) for two minutes according to the manufacturer’s instructions. After two minutes, the wound was thoroughly rinsed with saline. In half of the animals fed with HFSD, fenestration defects were treated with enamel matrix derivative (EMD, Emdogain^®, Straumann) (Figure 5d). EMD was applied with a sterile syringe provided by the manufacturer so that the complete defect was covered.

Wounds were closed with absorbable suture material (4.0 Vicryl, Ethicon, Johnson & Johnson Medical, Norderstedt, Germany) in two layers, one layer on the muscles and one on the skin. All animals received carprofen (5 mg/kg) as an analgesic. Wound healing, swelling and weight of the animals were monitored every other day for one week after surgery. No complications, such as wound infections, wound healing abnormalities, unnatural weight loss or death, occurred after surgery in any of the animals. All animals were sacrificed 4 weeks after surgery. The skulls of the rats were removed and stored in 4% phosphate-buffered formaldehyde (Merck, Darmstadt, Germany) for fixation.