Author/year | Study model | Defect | Healing period | Device | Clinical/gross presentation of dehiscence | Histological presentation of dehiscence |
---|---|---|---|---|---|---|
Friedmann et al. 2001 [44] | 16 human subjects | Chronic | 7mo | pDBBM covered with bovine type I collagen cross-linked CM | Within first 14d: Exposure of CM 7 out of 10 dehiscences completely closed within following 14 days 1 site completely covered by new gingiva with some exfoliated pDBBM after 4w 2 sites completely closed only 14d after the 6w review None of the dehisced sites showed any signs of inflammation, degradation, swelling, redness, exudation at any time point | At 7mo: No difference in appearance between membranes with and without exposure Possible that bacteria adhered to exposed membrane surfaces, but no granulocytic infiltration observed at 7mo Tissue apposition and ingrowth into gaps between the collagen layers occurred independent of membrane exposure |
Friedmann et al. 2002 [45] | 14 human subjects | Chronic | 7mo | pDBBM covered either with bovine type I collagen cross-linked CM or ePTFE membrane | With bovine type I CM: Within first 14d: 9 out of 14 sites had exposure of CM, complete closure after another 4w None of the dehisced sites showed any signs of inflammation, degradation, swelling, redness, exudation at any time point Uneventful delayed pattern of gingival healing With ePTFE membrane: Exposure during and after initial healing period Some required premature retrieval of membrane due to non-healing One site required complete removal of graft and membrane due to infection and severe inflammation | At 7mo: Dehiscence occurrence had no resulting difference in bone quality |
Friedmann et al. 2015 [46] | 12 human subjects | Chronic | 6mo | Biphasic calcium phosphate covered either with non-cross-linked CM or cross-linked CM | 7 out of 13 sites had compromised healing (wound dehiscence and/or graft exposure) | At 6mo: Low remodelling rates Osteogenesis detected in 4 out of the 7 sites, with the remaining displaying missing or minimal osteogenesis In cases with absent osteogenesis, the graft material was covered predominantly by dense collagen tissue populated by multinuclear cells resembling either osteoclasts or epitheloid giant cells with intermingled mononuclear cells |
Bornstein et al. 2007 [47] | 6 beagle dogs | Saddle-type defect created | 8, 16w | pDBBM + pABG (1:1 ratio) covered with either porcine type I and II CM or cross-linked porcine type I and III CM | At 1w: 2 out of 6 sites had exposure of CM and signs of local inflammation At 6w: Wound closure complete, no inflammation observed | At 8w: Less bone regeneration, remnants of cross-linked collagen barrier with signs of inflammation Dome shape contour of newly formed bone not apparent |
Donos et al. 2002 [48] | 30 Wistar rats | None (graft placed directly on ridge) | 15, 30, 60, 120, 180d | ABG covered with either resorbable membrane or ePTFE | At 15d: With ePTFE membrane: Membrane exposure in 5 out of 6 sites With resorbable membrane: Membrane exposure in 4 out of 6 sites At 30d: With ePTFE membrane: Membrane lost in 1 site, membrane exposure in remaining 4 out of 5 sites With resorbable membrane: Membrane exposure in 3 out of 6 sites At 60d: With ePTFE membrane: Microimplant lost in 5 out of 6 sites making histological preparation impossible. Membrane exposure in remaining site With resorbable membrane: Membrane exposure in 4 out of 6 sites At 120d: With ePTFE membrane: Microimplant, graft, membrane lost in 3 sites. Only membrane was lost in remaining 3 sites With resorbable membrane: Microimplant and graft lost in 2 sites. Membrane exposure in 3 out of the remaining 4 sites At 180d: With ePTFE membrane: Microimplant, graft, membrane lost in 5 sites. Only membrane was lost in remaining site With resorbable membrane: Microimplant, graft, membrane lost in 2 sites | At 15d: With ePTFE membrane: Graft contained osteocytes and had maintained its height. Periphery of graft had scalloped appearance due to resorption lacunae. Zone of connective tissue with numerous leucocytes, lymphocytes, plasma cells between graft and membrane. Richly vascularised granulation tissue between graft and recipient site With resorbable membrane: Exposed parts of membrane were fragmented and surrounded by connective tissue that had inflammatory infiltrate. Non-exposed parts had preserved their structure and embedded in connective tissue At 30d: With ePTFE membrane: Graft contained osteocytes, had scalloped surface. Inflammatory infiltrate between membrane and graft. Layer of fibrous connective tissue between the recipient site and graft (as opposed to newly formed immature trabecular bone in continuity between recipient site and graft, at the site with no dehiscence) With resorbable membrane: Membrane broken into large fragments, encapsulated by fibrous connective tissue with inflammatory cells. Bone graft had significant resorption especially at lateral edges of graft. Remaining parts surrounded by connective tissue with inflammatory infiltrate, and there was no bone continuity between recipient site and graft. Resorption of recipient bone had occurred (as opposed to newly formed mature trabecular bone in continuity between recipient site and graft, at the site with no dehiscence) At 60d: With ePTFE membrane: Bone graft had disappeared. Resorption of recipient bone had occurred With resorbable membrane: Small fragments of membrane could be detected. Bone grafts had empty lacunae. Two sites had graft that maintained its height, while two others the lateral border of the graft was exposed and inflammatory infiltrate was observed adjacent to the graft. Bone continuity between graft and recipient site was not observed in any site with membrane exposure At 120d: With ePTFE membrane: Bone graft partially or almost completely resorbed but two specimens had bone continuity between remaining parts of graft and recipient bone With resorbable membrane: Small fragments of membrane present adjacent to non-exposed lateral borders of graft. Exposed portion of graft had empty osteocyte lacunae, and height and width of graft was reduced due to resorption. Recipient bone also exhibited resorption. No bone continuity between graft and recipient site (as opposed to bone contact, at sites with no dehiscence) At 180d: With ePTFE membrane: Only 1 site had bone graft remaining, which contained osteocytes and had maintained its height. Bone continuity between graft and recipient bone was observed With resorbable membrane: Bone graft completely resorbed in 1 site. In remaining 3 sites, operated area covered by oral mucosa with very small remnants of membrane |