New collagen matrix to avoid the reduction of keratinized tissue during guided bone regeneration in postextraction sites.

For decades, there has been an ongoing controversy regarding the need for an "adequate" width of keratinized gingiva/mucosa to preserve periodontal and implant health. Today, the presence of a certain width of keratinized tissue is recommended for achieving long-term periodontal and implant success, and therefore, a new collagen matrix has been developed to enhance the width of keratinized gingiva/mucosa. During postextraction socket preservation, guided bone regeneration techniques require complete coverage of the barrier membrane to reduce the risk of infection, occasionally causing a reduction of the width of keratinized tissue. Using the new collagen matrix, it is possible to leave the membrane intentionally uncovered, without suturing the surgical flap above it, to avoid the reduction of such tissue.

Guided bone regeneration with autogenous block grafts applied to Le Fort I osteotomy for treatment of severely resorbed maxillae: a 4- to 6-year prospective study.

INTRODUCTION: Edentulism causes progressive bone resorption of the maxillae, which can lead to altered maxillo-mandibular relationships. The aim of the study was to evaluate the applicability of guided bone regeneration (GBR) to Le Fort I osteotomies with interpositional bone grafts for treatment of patients with severe maxillary atrophy. MATERIALS AND METHODS: Twenty consecutive patients characterized by severely atrophic maxillae were treated from January 2003 to January 2006 in order to resolve maxillary edentulism. All patients underwent pre-prosthetic surgery, including a Le Fort I osteotomy associated with autologous interpositional bone grafts to move the alveolar arch forward and to resolve the maxillary atrophy. Barrier membranes were also used to cover the bone grafts and the osteotomy line, favoring the healing process according to GBR principles. Maxilla advancement and alveolar crest augmentation were measured to assess the degree of reconstruction. A total of 154 implants were inserted in reconstructed maxillae 4 months after surgery and were restored with fixed full-arch dentures after another 4 months. Surgical and prosthetic complications were recorded and previously established implant success criteria were used to assess the success of this treatment protocol. RESULTS: The outcome of pre-prosthetic surgery and implant-supported rehabilitation was prospectively evaluated every year. All Le Fort I osteotomies were successfully carried out, with a mean maxilla advancement of 4.2 cm (range: 3.1-5 cm), which appeared to be stable during the follow-up. After a mean follow-up of 66.4 ± 18.4 months, only four implants failed according to the success criteria, yielding a cumulative success rate of 95.8%. DISCUSSION AND CONCLUSIONS: Le Fort I osteotomies with the use of barrier membranes to cover the interpositional bone grafts can be a predictable treatment for edentulous patients with severely resorbed maxillae. The study data suggest that this approach makes it possible to compensate for both sagittal and vertical discrepancies due to maxilla atrophy, with a minimum resorption of advanced maxillae and grafted bone. A GBR-based protocol seems to lead to high implant success rates, although further randomized controlled studies are needed to demonstrate the usefulness and advantageousness of GBR.

"Evidence-based dentistry in oral surgery: could we do better?".

Evidence-based Dentistry (EBD), like Evidence-based Medicine (EBM), was born in order to seek the "best available research evidence" in the field of dentistry both in research and clinical routine.BUT EVIDENCE IS NOT CLEARLY MEASURABLE IN ALL FIELDS OF HEALTHCARE: in particular, while drug effect is rather independent from clinician's characteristics, the effectiveness of surgical procedures is strictly related to surgeon's expertise, which is difficult to quantify. The research problems of dentistry have a lot in common with other surgical fields, where at the moment the best therapeutic recommendations and guidelines originates from an integration of evidence-based medicine and data from consensus conferences.To cope with these problems, new instruments have been developed, aimed at standardizing clinical procedures (CAD-CAM technology) and at integrating EBM achievements with the opinions of expert clinicians (GRADE System).ONE THING WE HAVE TO REMEMBER HOWEVER: it is necessary to use the instruments developed by evidence-based medicine but is impossible to produce sound knowledge without considering clinical expertise and quality of surgical procedures simultaneously. Only in this way we will obtain an evidence-based dentistry both in dental research and clinical practice, which is up to third millennium standards.