Atypical histological presentation of bone regeneration after insertion of cryoprotected allogeneic bone graf / Presentación histológica atípica de la regeneración ósea después de la inserción de un injerto óseo alogénico crioprotegido

ABSTRACT

Background: To evaluate bone regenerative capacity of cryoprotected corticocancellous allogeneic bone graftperformed in type II and III post-extraction sockets for ridge preservation after twelve weeks in-vivo.Material and Methods: Twenty-seven type II or III bony-walled extraction sockets (mandible and maxilla) wereselected for this study. Following atraumatic tooth-extraction a cryoprotected corticocancellous allogeneic bonegraft material and a resorbable porcine-derived collagen membrane were used for ridge preservation. Duringre-entry surgery at approximately 12 weeks, bone core biopsies were obtained using a 3.2 mm trephine drill andsamples were histologically processed and subjected to qualitative and quantitative histomorphometric analysis.Quantitative data was analyzed using a general linear mixed model with results presented as mean values with thecorresponding 95% confidence interval values. Results: Healing without incident and ridge preservation allowed for the placement of dental implants after 12 weeksin 25 out of the 27 treated socket sites. Analyses yielded an average of ~21.0±7% of old/native bone, ~17±5.5% ofnewly regenerated bone (total of ~38±12.8% for all bone), 0.23±0.14% of new bone presenting with nucleating siteswithin the matrix, ~52±5.12% of soft tissue, and 3.6±2.09% of damaged bone. The average regenerated bone wasstatistically analogous to that of old/native bone (p=0.355). Furthermore, an atypical histological pattern of boneregeneration was observed, with newly formed bone exhibiting “infiltration-like” behavior and with new bone nucle-ating sites observed within the demineralized bone matrix.Conclusions: Cryoprotected corticocancellous allogeneic bone-graft demonstrated osteoconductive, osteoinductive,and osteogenic properties, yielding unique healing patterns which does warrant further investigation.(AU)