Shell technique using a rigid resorbable barrier system for localized alveolar ridge augmentation

Objectives To assess the safety and efficacy of a rigid synthetic barrier system in a shell technique for localized alveolar ridge augmentation. Materials and methods Saddle‐type defects ( n  = 4 each) were prepared in the lower jaws of six fox hounds. At two defects, the outer contours were reconstructed using polylactic acid ( D and L isomers) ( PDDL ) pins welded to PDDL plates by ultrasound vibration and the defect area filled using either a natural bone mineral ( NBM ) or NBM + autogenous bone ( AB ) and covered by a native collagen membrane ( CM ). While the third defect was augmented using NBM + AB + CM , the fourth site was left untreated. At 14 weeks, dissected blocks were processed for histomorphometrical analysis [e.g., augmented area ( AA )]. Results AA values (median in mm 2 ) were significantly increased in all guided bone regeneration (GBR) groups [ NBM + PDDL + CM (19.74) > NBM + AB + PDDL + CM (16.98) > NBM + AB + CM (16.66)] when compared with the untreated control sites (7.34). Histological analysis has pointed, in the absence of any foreign‐body reactions, to biodegradation of both PDDL plates/pins and CM . Conclusions (i) All GBR procedures investigated equally supported bone regeneration, (ii) the application of PDDL + CM may be associated with increased mineralized tissue MT and subsequently AA values than CM alone, and (iii) AB may not improve healing at NBM + PDDL + CM ‐treated sites.