The management of vertical bone defects in the posterior area – The challenge

Abstract

Background The rehabilitation in the posterior area in the absence of adequate quantity and quality of bone represents one of the most complicated challenges in the implantology. The management of the atrophy can be performed with different methods and materials. The autogenous bone is still considered the best material for the regeneration of the bone defects particularly when we have to recovery atrophy in the 3 D dimension. Aim/Hypothesis The present study evaluated the reliability and predictability of the treatment of severe bone loss in the posterior maxilla and mandible. The inclusion criteria were the advanced bone defects due to previously lost teeth and complications of cases already treated with other materials and technique Material and Methods Of 32 consecutive patients were treated in the posterior area (premolar and molar) after failures of previous treatment or in the cases of severe 3D bone atrophy and followed from 4 years to 8 years post-operative. In all the cases was performed only a 2 stage approach due to the severe bone loss. All the augmentation were carried out according to Khoury's biological concept. The harvested bone block from the mandibular retromolar area with the Microsaw, was splitted in 2 thin blocks and they were screwed to reconstruct at least two bone walls with the micro screws allowing a 3D reconstruction of the alveolar crest. The space between the two blocks were filled with particulate bone chips collected with a bone scraper. 22 reconstructions were carried out in the maxilla and 18 in the posterior mandible. No membranes were used. Implants were placed 4 months after the augmentation. The soft tissue management and augmentations were performed during the implant exposure 3 months post-operative Results A primary good healing occurred in all the 32 patients. No exposure of the grafts was registered after the augmentation or at the moment of implant insertion. The grafted bone after 4 months showed a good revascularization and stable bone volume showing the same consistence and bleeding like the native bone. Therefore, we proceeded to insert 93 implants with regular diameter (3.4–4.5 mm) and length (9.5–13 mm) in the augmented posterior area in the mandible and in the maxillary as we planned. In only two patients a secondary bone augmentation with local harvested bone was necessary due to incomplete bone regeneration (both cases were complication of previous reconstruction techniques). All the patients presented after a follow-up between 4 and 8 years a good function and aesthetical result with the correct hight of the crowns. The radiographic control, repeated every year, documented the stability of the grafted and regenerated bone. Conclusion and Clinical Implications The management of bone defects in 3D dimension represents a big challenge particularly when the demand of the patient is really important. With the biological concept we were able to ensure a long-term stability with very good outcomes for aesthetics and function. The use of autogenous bone offered more safety and reduced considerably the time of the treatment in comparison to other augmentation materials remaining nowadays more reliable and predictable.