Surface characteristics of biomaterials used for space maintenance in a mandibular defect: a pilot animal study.
OBJECTIVE
The purpose of the present study was to evaluate the effect of implant porosity on wound healing between solid and porous implants placed within a bony mandibular defect with intraoral exposure.


METHODS
Solid poly(methyl methacrylate) (PMMA) implants similar to those used currently in clinical space maintenance applications in maxillofacial surgery were compared with poly(propylene fumarate) implants that contained a porous outer surface surrounding a solid core. A 10-mm diameter nonhealing bicortical defect with open communication into the oral cavity was created in the molar mandibular region of 12 adult male New Zealand white rabbits. Of the 12 rabbits, 6 received the hybrid poly(propylene fumarate) implants and 6 received the solid PMMA implants. At 12 weeks, the rabbit mandibles were harvested and sent for histologic staining and sectioning.


RESULTS
Gross inspection and histologic examination showed all 6 poly(propylene fumarate) implants to be intact within the defect site at the termination of the study period, with 3 of the 6 specimens exhibiting a continuous circumferential soft tissue margin. In contrast, 5 of the 6 PMMA-implanted specimens were exposed intraorally with an incomplete cuff of soft tissue around the implant. One of the PMMA-implanted specimens exhibited complete extrusion and subsequent loss of the implant. Fisher's exact test was used to compare the occurrence of oral cavity wound healing between the 2 groups (P = .09).


CONCLUSIONS
Although statistically significant differences between the 2 groups were not seen, our results have indicated that advantages might exist to using porous implants for space maintenance. Additional study is needed to evaluate these findings.
Resident in Oral and Maxillofacial Surgery, Department of Oral and Maxillofacial Surgery, University of Texas Health Science Center at Houston, Houston, TX, USA.
Charles
C
Nguyen
Simon
S
Young
James D
JD
Kretlow
Antonios G
AG
Mikos
Mark
M
Wong
D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry*; D003238:Connective Tissue / Q000473:pathology; D004195:Disease Models, Animal; D004487:Edema / Q000209:etiology / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005650:Fumarates / Q000138:chemical synthesis / Q000737:chemistry; D006097:Granulation Tissue / Q000473:pathology; D006644:Histiocytes / Q000473:pathology; D008214:Lymphocytes / Q000473:pathology; D008297:Male; D008334:Mandible / Q000473:pathology / Q000601:surgery; D008336:Mandibular Diseases / Q000601:surgery*; D008422:Materials Testing; D009061:Mouth Mucosa / Q000473:pathology; D009504:Neutrophils / Q000473:pathology; D010865:Pilot Projects; D019904:Polymethyl Methacrylate / Q000138:chemical synthesis / Q000737:chemistry; D011126:Polypropylenes / Q000138:chemical synthesis / Q000737:chemistry; D016062:Porosity; D019736:Prostheses and Implants; D011474:Prosthesis Design; D011817:Rabbits; D013499:Surface Properties; D013529:Surgical Wound Dehiscence / Q000209:etiology / Q000473:pathology; D014945:Wound Healing / Q000502:physiology
D001672:Biocompatible Materials; D005650:Fumarates; D011126:Polypropylenes; C097850:poly(propylene fumarate); D019904:Polymethyl Methacrylate