Dental Tribune United Kingdom Edition

Rehabilitation of an atrophic mandible with 3D planning Authors: Rainer Fangmann & Lars Steinke Introduction Patients with fixed restora- tions in the form of large-span bridges often wish to retain a fixed solution, even if the dis- tal bridge abutments have been lost. Yet prosthodontists advise a shift in treatment to a remov- able prosthesis. This is due to a lack of knowledge of current possibilities regarding bone augmentation and implanta- tion. The argument that im- plant-borne (fixed) restorations promise quality of life, appeal and youthfulness is ignored. As a consequence, removable restorations are only partially accepted and result in patient dissatisfaction in the long term. The desire for permanent re- habilitation remains. The pportunity for immediate place- ment of an implant and, if nec- essary, augmentation of the pos- terior section of the mandible to address resorption is missed. Initial situation A 71-year-old female non- smoker in a good general and nutritional state presented with multiple prosthetic restora- tions in the maxillae, consisting of bridges and single crowns placed at different times. The mandible revealed an insuf- ficient denture. Tooth 43 had been destroyed by caries under the crown and had a treated root canal (Fig. 1). The patient requested rehabilitation with a fixed prosthesis. As a result of years of wearing removable prostheses, the mandible re- vealed an atrophy pattern of re- sorption Class V–VI on the right and Cawood Class IV on the left.1 Procedure Treatment planning Bone augmentation with au- tologous material from the ret- romolar region/corpus of the respective sides and delayed im- plantation was discussed with the patient. She requested a pre- operative 3D image (Fig. 2) to clarify the necessity of augmen- tation. Three-dimensional plan- ning with coDiagnostiX (Dental Wings) for implant placement and immediate restoration via Multi-Base Abutments (Strau- mann) was recommended after augmentation. Surgical procedure The patient requested general anaesthetic during bone aug- mentation. This was followed by the typical incision of the gingival margin and appropri- ate mesial and distal relieving incisions. Once the dimensions of the receiving site had been determined, the corresponding mandibular ramus and/or cor- pus site was selected. After determining the di- mensions and the morphol- ogy of the bone graft, the mo- no-cortical bone block was harvested from the donor site2, 3 by piezo-surgery4 (Fig. 3). Us- ing a Safescraper (Meta Ad- vanced Medical Technology),5 this was thinned down extra- orally to a final thickness of 1 mm. The thinned block served as a biological membrane to stabilise the particulate bone material vestibularly and oral- ly. First, a cortical lamella was fixed occlusally over the os- teosynthesis retaining screws in gliding holes (Fig. 4). This lamella was lined with cortical chips soaked in autologous ve- nous blood. In order to secure the graft, it was covered with a further lamella vestibularly, which was fixed with osteosyn- thesis retaining screws (Fig .5). This was followed by fully tightening the screws inserted into the gliding holes of the oc- clusal lamella to compress the particulate graft. This was fol- lowed by wound closure with sutures. On the left side, aug- mentation was performed by applying the tongue-in-groove technique6–8 (Figs. 6–8). Clinda- mycin 600mg was administered as a short intravenous infusion and continued orally over six Fig. 3 Fig. 1 Fig. 2 Fig. 4 Fig. 5 page 12DTà CAD/CAM Tribune pages 11-13 Using 3D planning Rehabilitaion of an atrophic mandible CAD/CAM Tribune pages 14-15 Terence Whitty discusses the Maestro 3D Dental Scanner Maestro Scanner system CAD/CAM Tribune pages 16-18 A case study by Khaled Abouseada Non-extraction treatment CAD/CAM Tribune

Dental Tribune United Kingdom Edition

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