O.557 Bone graft healing in reconstruction of maxillary atrophy

O.557 Bone graft healing in reconstruction of maxillary atrophy

S140 Journal of Cranio-Maxillofacial Surgery 36(2008) Suppl. 1 not significant (P = 0.25). The autogenous bone was initially less visible than the Be...

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S140

Journal of Cranio-Maxillofacial Surgery 36(2008) Suppl. 1

not significant (P = 0.25). The autogenous bone was initially less visible than the Beta-TCP, but new bone formation was clearly observed for both materials. The rate of graft resorption was lower on the experimental side than on the control side. The mean graft area percentages were 13.95±5.38% and 8.47±3.17%, and the difference was highly significant (P < 0.001). Conclusion: Comparisons with other studies reveal that BetaTCP is a satisfactory graft material for maxillary sinus floor augmentation, even without autogeneous bone. O.557 Bone graft healing in reconstruction of maxillary atrophy M. Sj¨ostr¨om1 , L. Sennerby2 , S. Lundgren1 . 1 Department of Oral & Maxillofacial Surgery, Ume˚a University, Ume˚a, Sweden; 2 Department of Biomaterials, University of Gothenburg, Sweden Objectives: To evaluate possible correlations between loss of volume of free iliac crest bone grafts in the maxilla during six months of healing and factors such as bone mineral density, bone volume fraction and haematological bone metabolic factors in blood. The aim was to identify possible indicators of implant failure. Methods: Forty-six consecutive patients (31 women/15 men, mean age 57 years, range 44−74) had their edentulous atrophic maxilla reconstructed with free autogenous bone grafts from anterior iliac crest. Endosteal implants were placed after six months of bone graft healing. Radiographic examination using computer tomography was performed in 30 patients with onlay bone grafts within 3 weeks after bone grafting and after six months of bone graft healing, and the graft volume change (GVC) during the first six months of healing was calculated. The bone volume fraction (BVF) was estimated from biopsies taken from the internal table at the donor site. Blood samples were collected from 25 of the patients, and in 21 patients the bone mineral density (BMD) was measured with dual-energy x-ray absorptionsmetry. Implant stability was measured at the time for implant placement with resonance frequency analysis (RFA) and expressed as implant stability quotient (ISQ). Implant failure was registered for each patient prior to loading (early failures) and up to three years after loading (late failures). Results: The mean decrease in onlay bone volume after 6 months was 37% (range 16−59). The mean BVF in iliac crest biopsies was 32% (range 15−74). Serum-IGFBP3 was the only haematological parameter differing from the normal range with 79% of the samples over the normal range. Fifteen patients had one or more implant failures prior to loading (early failures). Forty-two out of 46 patients were followed for a minimum of 3 years after loading of the implants. In addition, 6/42 patients had to have one or more implants removed during the three-year follow-up period (late failures). GVC (loss) was correlated with decreased BMD of the lumbar vertebrae L2-L4 (Kruskal Wallis test, p = 0.017). No correlation was found between GVC and haematological factors (Pearson correlation test) or between GVC and BVF (Kruskal Wallis test). No correlation was found between ISQ and graft volume change (Pearson correlation test, p = 0.865). The association between the early and late implant failures and the described factors were evaluated with unconditional logistic regression, and no significant correlations were found. Conclusions: The volume of onlay bone grafts in the maxilla decreased by, on average 37% during the 6-month healing period prior to implant placement. The amount of loss was significantly correlated with BMD of lumbar vertebrae L2-L4. BVF and haematological factors did not correlate to GVC. No correlations were found between graft volume change and implant stability expressed in ISQ nor between implant failure and the other factors evaluated in this study.

Abstracts, EACMFS XIX Congress O.558 Clinical evaluation of DBX in sinus lift procedure U. Zanetti1 , G. Nicoli2 . 1 U.S.D. Maxillo Surgery, Brescia, Italy; 2 Maxillo Facial Surgeon Private-Practitioner, Italy Introduction: A clinical evaluation of the use of DBX alone or associated with autogenous bone graft in sinus lift procedures is esposed. Material and Methods: 18 sinus lift procedures in 10 patients, 8 bilateral, 2 monolateral, were performed in a period during 1 year from 2006 to 2007. In 10 sinus lift, DBX was associated with autogenous bone graft collected from the same side without any other incision, while in 8 cases DBX was used alone. Results: after a healing period (from 6 to 8 months) during the phase of implants placements, a sample of new tissue was analyzed by pathologist and results compare. In all cases enough bone for implant placement was obtained, but preliminary results show a better mineralization where DBX was used associated with bone graft. The osteo-inductive capacity of autogenous bone, even if in small quantity, seem to determine the better results. O.559 Current treatment concepts with immediate implantation W. Wagner, R. Noelken, M. Kunkel. Clinic for Maxillofacial Surgery, Mainz, Germany Purpose of these retrospective studies is to evaluate implant success, marginal bone level and gingival esthetics of 159 NobelPerfectTM implants with immediate provisionalization in the esthetic zone and to explore the performance of a new flapless surgical approach for immediate implant placement, simultaneous alveolar ridge augmentation and immediate provisionalization in case of total loss of the facial bony lamella due to long-axis root fracture. 32 NobelPerfect™ implants with machined neck and 127 NobelPerfect™ Groovy implants were inserted in 99 patients and restored immediately with provisional crowns (follow up period 6 to 48 months). 21 Nobel Perfect™ implants were placed in 19 patients (follow up 3 to 36 months), which had sustained complete loss of the facial bony lamellae. In a flapless technique, implants were inserted simultaneous to subperiostal bone augmentation with autogenous bone chips and underwent immediate provisionalization. Outcome variables were implant success rates, marginal bone levels and Pink Esthetic Score (PES). In the follow up period one implant of the NobelPerfect™ group (cumulative success rate 96.9%) and one implant of the NobelPerfect™ Groovy group (99.2%), but no implant of the group without facial bony lamella (100%) got lost. Marginal bone levels averaged 1.7 mm in the NobelPerfect™ group, 1.99 mm in the NobelPerfect™ Groovy group and 1.87 in the group without facial bony lamella coronal to the first thread. The mean PES of the NobelPerfect™ and NobelPerfect™ Groovy implants was 11.3, of the group without facial bony lamella 12.5. The Groovy design improved the possibility to keep the PES of the initial clinical situation stable or even improve it. Oral hygiene (SBI) was predictive for the esthetic result. The presented data suggest proof of principle for the preservation of the marginal soft tissue height and the reduction of marginal bone remodeling and show that modern implant designs and surfaces make immediate function to a predictable and successful treatment concept. Oral hygiene status should be considered for patient allocation to single stage or multiple stage treatment.