Objectives: To evaluate the 5-year clinical outcome of regenerative periodontal therapy (RPT) using minimally invasive surgery and a collagen-enriched bovine-derived xenograft (1), and to identify predictors for gains in clinical attachment level (CAL) and vertical radiographic bone (RB) (2). Methods: Subjects were 95 non-smoking patients, with up to 25% full-mouth plaque and bleeding presenting at least 6 months after initial periodontal therapy with more than one isolated interdental infrabony defect. They were treated consecutively by the same clinician with combined surgery and xenograft. Clinical and radiographic data were collected before surgery, and after 1 year and 5 years. Results: Eighty-four patients (39 men, 45 women, mean age 53 years) were available for follow-up after 1 year and demonstrated a mean probing depth (PD) of 7.8mm, a CAL of 10.0mm and a defect depth of 5.2mm before surgery. Thirteen patients dropped out between year 1 and year 5. At 5 years, mean PD reduction was 3.3mm (SD 2.2 ), CAL gain was 3.0mm (SD 2.1) and RB gain was 57% (SD 38). Of these, 45% showed ≥4.0mm CAL gain, and 24% were considered failures (≤ 1.0mm CAL gain), 48% showed considerable RB gain (≥75%).The only predictor for CAL gain included sites that were always plaque-free during aftercare (p= 0.003). Predictors for RB gain included patient compliance (p=0.001) and sites that were always plaque-free during aftercare (p=0.010). Conclusions: Regenerative periodontal therapy using minimally invasive surgery and a collagen-enriched bovine-derived xenograft demonstrated favourable clinical and radiographic outcomes after 5 years. Oral hygiene and patient compliance had a significant impact in the long term.

Objectives: In clinical cases where a severe horizontal bone deficiency is present, it is very difficult to install implants in the perfect position for achieving optimum aesthetics and functional rehabilitation. The split-crest technique leads to reduced waiting times for installation of implants for maxillary defects of less than 3mm. The cases reported here underwent the split-crest technique with interposition of Bio-Oss biomaterial and were reopened for implant placement after five months. Methods: Patients were selected with a horizontal bone deficiency in the maxilla of 1.6–2.3mm. Both were fit for surgery. The preoperative assessment consisted of blood tests, CT scans and antibiotic prophylaxis and full treatment plans were presented to the patients. Infiltrative terminal anesthesia was applied until satisfactory tissue ischaemia was produced. An incision was made above the crystal with 15c blades and mesiodistal relaxing incisions. After total detachment and bone mucoperiostal exposure, a tag 701 was made with a surgical drill at the cortical level, completed with a metal disc osteotomy. A chisel was used between the markings to achieve total displacement of cortical , to achieve sufficient expansion and an intact nasal spine . Screws were placed at the base of each fracture, preventing vestibular cortical blades from moving during bone maturation. Gaps and remaining spaces were filled with Bio-Oss. Bio-Gide membranes were applied, the flap repositioned and the wound was closed by suturing without tension. Results: CT scans four months postoperatively showed increased bone width of approximately 5.2mm. There were no complications and both patients reported little discomfort after surgery. Both underwent further surgery for implant placement after five months. Primary stability of all implants was achieved and manufacturing the prostheses. Conclusion: The split-crest technique is a feasible option. Using Bio-Oss with a Bio-Gide membrane increased the maxillary bone thickness, which facilitated rehabilitation with dental implants.

These tests are carried out before preclinical studies. They are essential for exploring fundamental responses to procedures such as creating wounds in gum and bone and inserting foreign materials. Success of these interventions depends on the stability of the supporting tissues and the capacity to heal, involving the formation of blood clots and granulation tissue, and the growth of new bone and soft tissue. Screening studies tend to use small animals, often rats, to quickly and easily identify agents that show promise for preclinical studies in larger animals, which are more expensive and time consuming. The models described in this chapter include rats with induced defects of the long bones, the mandibular symphysis and ramus, and the calvarium, and addresses their suitability for testing different shapes, features and locations of implants. These studies yield information on biocompatibility at cellular, vascular and biochemical levels, as well as responses to surgical trauma and repair. The chapter emphasizes the need to use standardized, validated screening protocols to generate reproducible results, and cites specific protocols developed by various international organizations. If all screening tests meet certain basic criteria on study variables, control groups and the accessibility, homogeneity and mechanical stability of implant sites, they will comply with regulatory requirements and allow easy comparison with the existing evidence base.