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ePaper created 2016-10-04, 09:33:57 | version 1.38.0
implant-supported prosthesis can be seen in Figs.10a&b.Thepost-insertionradiographicimage at 14 months revealed excellent bone adaptation surrounding the implant, with sufficient interprox- imal height of bone (Fig. 11). Discussion Adifferentialdiagnosistothecauseoftheproblem associatedwiththepatient'smaxillaryrightcentral incisorwasambiguous.Thepatientdidpresentwith a history of trauma but the typical findings of wounds, injuries to the oral mucosa, fracture of the tooth, pulp exposure, vitality tests, displacement andmobility15 werenotevident,thoughthepatient did report displacement. Another potential diag- nosis could be localised aggressive periodontitis, whichexhibitsitselftypicallywithsmallamountsof plaque, mobility and migration of the molars and incisors, an increase in the size of the clinical crown and rapid progression.16 Alternate treatment modalities included a remov- ablepartialdenture,fixedpartialdenturesandresin bondedbridges(Marylandbridges).Removablepar- tial dentures, while a viable option, can contribute to the loss of alveolar bone on both abutment and non-abutment teeth.17 The dissatisfaction rate of removable partial dentures is relatively high.18 The use of fixed partial dentures would have required the unnecessary destruction of adjacent teeth with pristine tooth structure to prepare anchor abut- ments. Another option would be a resin-bonded bridge,whichwouldreducetheamountofadjacent toothdestructionbutwithahighincidenceofpon- ticfailureandde-bonding.19 Usingtheclassification system proposed by Funato et al. 2007, the site in this case was Class IV, which is characterised by verticalandbuccalboneloss.20 Itwasthusnecessary to perform bone and tissue augmentation so that optimal gingival profiling and a more aesthetic re- sult could be achieved. Reconstruction of defects in the anterior part of the maxilla to enable implant placement is a chal- lenging treatment. The alveolar ridge augmenta- tion, along with GBR, has been introduced in recent years to re-establish an appropriate alveolar ridge width. Bone regeneration in membrane-protected defects heal in a sequence of steps that stimulated bone formation after tooth extraction. After blood clotformation,boneregenerationisinitiatedbythe formation of woven bone initially along new blood vasculature at the periphery of the defect. The wo- venboneissubsequentlyreplacedbylamellarbone, which results in mature bone anatomy. Ultimately, bone remodelling occurs with new, secondary os- teons being formed. Bone graft materials have been used to facilitate bone formation within a given space by occupying that space and allowing the subsequent bone growth. The biologic mechanisms that support the use of bone graft materials are osteoconduction, osteoinduction and osteogenesis. Barrier mem- branes are biologically inert materials that serve to protect the blood clot and prevent soft tissues cells (epithelium and connective tissue) from migrating intothebonedefect,allowingosteogeniccellstobe established. Vertical increase of a narrow alveolar crest has been shown to be possible with mem- branes.21, 22 Membranes have been manufactured from biocompatible materials that are both non- resorbable and resorbable. The advantage of a titanium barrier membrane (non-resorbable) is its ability to maintain separation of tissues over an case report cone beam supplement | 53 CAD/CAM 3 2016 Figs. 7a–d: Computed tomography scan after 5 months. Figs. 8a & b: Comparison of pre- and post-operative CBCT. Fig. 8a Fig. 8b Fig. 7a Fig. 7b Fig. 7c Fig. 7d 32016