All ETDs from UAB

Advisory Committee Chair

Michael S Reddy

Advisory Committee Members

Mia Geisinger

Nico Geurs

Amjad Javed

Philip J Vassilopoulos

Document Type


Date of Award


Degree Name by School

Master of Dentistry (MDent) School of Dentistry


Spontaneous early exposure of a dental implant's cover screw can result in a nidus for plaque accumulation, which may result in inflammation, damage to the peri-implant mucosa, and possible peri-implant bone loss. This study aims to investigate the effect of the addition of growth factors, specifically recombinant human platelet-derived growth factor, and platelet-rich plasma, at the time of socket conversion, on the incidence of early implant exposures. This retrospective study utilized data from a study involving a total of 80 implants that were placed in 4 different types of sites (Groups 1,2,3, and 4). Group 1 sites were extraction sites that were allowed to heal naturally without any grafting material or growth factors added. Group 2 sites were extraction sites that received a tri-calcium phosphate (TCP) mixed with freeze-dried bone allograft (FDBA) grafting material, but without any addition of growth factors. Group 3 sites were extraction sites that were grafted with TCP/FDBA graft, and also had platelet-rich plasma (PRP) added. Group 4 sites were extraction sites that were grafted with TCP/FDBA graft, and had recombinant human platelet-derived growth factor added (rh-PDGF). Two different types of implant surfaces were also investigated: A resorbable blast textured (RBT) surface, and a laser thread-textured implant surface (Laser-Lok®). Radiographs and photographs taken at time of implant placement, 2 weeks post-operatively, and at time of implant uncovery, were compared to determine whether an early implant exposure had occurred, and also to determine the amount of bone loss that occurred. After evaluation for completeness of records and for inclusion criteria, 43 implants were accepted to be evaluated for soft tissue exposure, of which, 32 implants were accepted to be evaluated for bone loss. There was no statistically significant difference between the groups with growth factors used at the time of socket conversion, and those without, with regards to frequency of spontaneous early dental implant exposure. Likewise, no differences between implant surfaces were noted. The overall incidence of early implant exposure was 35% in this study. Bone loss was significantly greater for implants that had early implant exposure, versus implants that had no visible exposure.

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