Dental Tribune United Kingdom

21Implant TribuneAugust 1-7, 2011United Kingdom EditionUnited Kingdom Edition A high clinical evidence of grafting procedures from extraoral autolo- geous donor sites like from the iliac crest in difficult bone loss sites is still the practice in oral or oral-maxillofacial surgery. However, the invasive surgery combined with a prevalence of patients morbidity and suffer is an issue to discuss the persisting legitimation of this procedure. Since the appearance of reli- able bone substitute materials with or without any autologeous bone added, the positive results concerning longterm stability of regenerated bone even in dif- ficult cases have become very predictable. This article will point out in a case report the reliability of alternative and less invasive techniques for 3-D bone recon- struction in the mandible and question the necessarity of iliac hip grafts for intraoral bone aug- mentation. Materials and methods A female patient aged 48 years old with a severe and advanced periodontitis in the maxilla and the mandible came into our clinic with the desire of a complex treatment plan with an implant retained denture in both jaws. This case report will pinpoint the treatment of the mandible. A CBVT was reveal- ing massive bone loss in height and width in the mandible arch from canine to canine and api- cal cyst at tooth 23, 26 and 28 (Figs 1 & 2). According to our protocol we started with an ini- tial scaling and HELBO®-Laser decontamination prior to the surgery to decrease the number of pathologic germs and post op infections. Tooth 18 and 19 in the left mandible were intended to maintain until the finalisation of the prosthetics to give some comfort during temporisation with an immediate denture that was placed post op. Preoperative the patient received 1,200mg of Clindamycin. The patient de- sired the surgery of tooth re- moval and ridge augmentation persued under general sedation. After nasal intubation and local anaesthesia the bridge in the lower was removed and the remaining teeth despite from 18 and 19 as mentioned before (Figs 3 & 4). After full flap prepa- ration with crestal incision, re- leasing incisions and exposure of the mental nerve exit, the vol- ume of the severe bone loss was revealed as well as the minor soft 3-D alveolar ridge recon- struction in a case with severe bone loss tissue conditions due to inflammatory tissue prolifera- tion (Figs 5 & 6). The success of 3-D bone augmentation is bond- ed to primary wound closure and tensionless flap adaptation. Thus, the periosteum is dissect- ed with a scissor from the epipe- riostal connective tissue before augmentation procedures to re- duce bleeding and guarantee a flap flexibility without compro- mising soft tissue and nutritive blood vessels. For bone augmentation a bone block was harvested via ultrasonic surgery from the ret- romolar region distal from 32 of the right mandible (Piezotome II, Acteon France). This bone block was divided into two halves. One was used for two “bone shields” to create a mold for the grafting mate- rial, one was particulated with a bone mill and mixed with defect blood and a beta-TCP (Nanobone®, Artoss GmbH, Rostock, Germany). The bone blocks were fixed with two os- teosynthesis screws (Fig 7) and the mixture of autologenous bone plus beta-TCP in mix- ing ratio 50:50 was used to fill the gaps and increase the ridge width and height. To increase the bone augmentation material volume an allograft block (Puros®, Zimmer Dental) was particulated and added to the mixture. Before placing the material a non resorbable titaniumre- inforced membrane (Cytoplast Ti-250, Sybron Implant Solu- tions) was adapted lingually and folded to shape the augmenta- tion complex according to the new and desired crest volume (Fig 8). Upon the non resorbable membranes three xenogenous resorbable membranes (Tu- todent®, Zimmer Dental) were placed according to the sand- wich membrane layer technique to create a better adaptivity to the flaps (Fig. 9) and enhance wound healing. Primary wound closure (Fig 10) was achieved with a 4-0 metric suture (Gore- Tex®, Gore). The patient carried a clamb retained provisional denture that was rebased with a soft material and was instructed to have no solid food for 10 days. 3-D alveolar ridge reconstruction Prof Dr Marcel Arthur Wainwright discusses a case with severe bone loss Fig. 1 Presurgical aspect revealing mas- sive Periodontitis and bone resorption in region 32, 42, 44 Fig. 2 The CB-Scan exposing region 32— with partial loss of the buccal and lingual wall region 32–44 Fig. 3 Site before bridge removal and extraction Fig. 4 Surgical Site after bridge removal and extraction of teeth 33, 32, 42, 43, 44 Fig. 5 After Cystektomy the dramatic severe horizontal and vertical bone loss is visible Fig. 6 Frontal aspect of the compromised bone situation Fig. 7 Fixation of the autologous bone blocks which have been harvested ultrasonically from the retromolar region of the right mandible Fig. 8 3-D crest reconstruction with the “mold-technique” with clearly visible hori- zontal and vertical augmentation Fig. 9 Resorbable collagenous membranes are placed upon the non resorbable membranes Fig. 10 Wound closure with 4-0 metric GoreTex sutures after flap mobilasation Fig. 11a Membrane exposure of the non resorbable ePTFE membrane after four weeks. Clearly visible is the enhanced soft tissue situation page 22DTà ‘Since the appearance of reliable bone sub- stitute materials with or without any au- tologeous bone added, the positive results concerning longterm stability of regenerat- ed bone even in difficult cases have become very predictable’