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implants - international magazine of oral implantology

I case report Fig. 10_Frontal CT after six months. Fig. 11_(a) Horizontal and (b) lateral CT after six months. whichmayresultinwoundinfection.Leavingapost- resection area of a size similar to the presented case unfilled could lead to an aesthetic defect or even complications such as loss of the resected teeth or fracture. Intheliterature,varioustreatmentsaredescribed toavoidsuchcomplicationsandtopromotebonere- generation.Schultedescribesamethodinwhichthe bloodclotisstabilisedwithcollagenspongessoaked with antibiotics to reduce the contraction of the clot.7 Later, this method was modified by using cen- trifuged blood.8 Alternatively, the curetted defect maybefilledwithautogenousbone,whichhowever will cause additional morbidity at the graft donor site.Theuseofbonesubstitutesenablesthesurgeon to stabilise the clot without graft harvesting. Bone substitutes differ in their origin (allogeneic, xeno- genetic or synthetic) and their behaviour in the hu- manbody(resorbableornon-resorbable).Mostbone substitutes are applied in granular form. Depending ondefectsize,formandlocation,securingthemate- rial with dental membranes is necessary. Generally, bone defects resulting from cyst enucleation are multi-walledandnotmechanicallychallenged,thus bone regeneration is reproducible and reliable if ap- propriate osteoconductive scaffolds are used. In the case presented, the authors used an in situ hardening biphasic bone substitute to fill a large bone defect. The size of the defect and the partially missing lingual and vestibular cortical bone walls constituted a challenging situation for which the in situ hardening property of the material used and its slow resorption were advantageous. The material could be modelled to fit the defect shape and to follow the anatomical contour of the lost alveolar bone. The material hardens upon con- tact with blood. Thus, mobility of graft particles or deformation of the graft during early healing is pre- vented, which is important for large bone defects. Boneregenerationiscentripetal(i.e.boneforma- tion starts from the defect walls and continues to- wards the defect centre). It is evident that bony re- generationthuswilltakelongerinlargedefectsthan in small defects (e.g. extraction sockets). Conse- quently, resorbable materials such as phase-pure ß-tricalcium phosphate or calcium sulphate may be degradedbeforeregenerationoflargedefectscanbe attained, which may result in incomplete bone fill. Biphasic calcium phosphates are compounds of hy- droxyapatite(virtuallynon-resorbable)andß-trical- cium phosphate (resorbable). Materials with a com- position of 60% hydroxyapatite and 40% ß-trical- cium phosphate have a long and successful history of clinical use. Histologically, bone substitute parti- clesappeartobeintegratedintonewlyformedbone. Thehistologicalfindingsaresimilartotheresultsob- tainedwithbovinebonesubstitutes.9–11 Forthepres- entcase,abiphasiccalciumphosphatewaspreferred in order to guarantee integrity of the calcium phos- phatescaffoldduringtheexpectedprolongedperiod ofboneregenerationowingtothesizeofthedefect. Histological evaluation of the regenerated hard tis- sue in the present case was not possible, since it would have necessitated reopening the site. How- ever, the radiological results demonstrated that the entirecavitywasfilledwithradiopaquetissue,which is consistent with complete bone regeneration and adequate bone substitute resorption for large cavi- ties. _Conclusion The case report has demonstrated how an in situ hardening biphasic bone substitute (easy-graft CRYSTAL) can be used successfully to treat large de- fects originating from cystectomy in oral and max- illofacial surgery. The material’s in situ hardening property and slow resorption were considered to be crucial for the treatment of the case. The authors usedaresorbablemembranetocoverthebonegraft on the vestibular side. Further studies will be neces- sary to determine the indications for which the ap- plicationofamembraneisuseful,orwhetherabone substitute used without a membrane is sufficient._ Editorial note: A complete list of references is available fromthepublisher. 36 I implants1_2013 Fig. 11aFig. 10 Fig. 11b Dr Damian Dudek ul.Ruska 32A, 42-200 Czestochowa,Poland Tel.:+48 604 124-520 damiandudek@op.pl _contact implants