J Oral Maxillofac Surg 70:154-162, 2012 Evaluation of Graft Cell Viability—Efficacy of Piezoelectric Versus Manual Bone Scraper Technique Karin Pekovits, MD,* Angelika Wildburger, DMD,† Michael Payer, MD, DMD,‡ Heinz Hutter, PhD,§ Norbert Jakse, MD, DMD,¶ and Gottfried Dohr, MD Purpose: The aim of the present study was to compare the influence of 2 different bone scrapers with respect to graft quality. Materials and Methods: The study was conducted as a prospective, controlled experimental study of patients selected from the outpatient unit of the Department of Oral Surgery and Radiology (Dental Clinic, Medical University, Graz, Austria). Bone samples were obtained during routine lower third molar removal. Both a manual bone scraper (MS) and a piezoelectric device (PD) were used in directly adjacent regions in each case. As variables, the chip morphology, cell viability, and osteogenic differentiation were investigated. For statistical analysis, the Student t test and Fisher’s exact test (P  .05) were applied. Results: A total of 20 patients (12 women and 8 men, mean age 28.15  5.8 years) were included in the study. A series of 40 bone samples was obtained during lower third molar removal. MS and PD enabled similar intraoral harvest of bone chips. In vitro outgrowth of adherent cells was found in 90% of the MS and 80% of the PD samples after 7 to 18 days, without statistical significance (P = .67). Similar cell viability of outgrowing cells in both groups was observed (94.7%  2.2% in the MS group and 94.1%  1.6% in the PD group). Reverse transcriptase-polymerase chain reaction analysis and the staining pattern verified osteopotent cells in both groups. Conclusions: Both manual and piezoelectric techniques are adequate harvesting technologies for limited intraoral augmentations. Our results did not show an advantage for the piezoelectric device. © 2012 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 70:154-162, 2012 Autogenous bone is still considered the reference standard for bone regeneration in oral and maxillofa- cial surgery owing to its osteoconductive, osteoinduc- tive, and osteogenetic properties. 1,2 The main indica- tions for autogenous bone harvesting in oral surgery are reconstruction of the atrophied alveolar crest, repair of traumatic or postinfective bone defects, and augmentation of the maxillary sinus before or during placement of dental implants. 3-5 Although advanced bone defects require bone grafts harvested from ex- traoral sites such as the iliac crest 6-8 or the proximal tibia, 1,9 more common defects are regenerated using intraoral bone grafts. Intraoral donor sites such as the oblique line, mental protuberance, maxillary retromo- *Medical Doctor, Institute of Cell Biology, Histology, and Embry- ology, Medical University of Graz, Graz, Austria. †Dental Medical Doctor, Department of Oral Surgery and Radi- ology, Dental School, Medical University of Graz, Graz, Austria. ‡Assistant Professor, Department of Oral Surgery and Radiology, Dental School, Medical University of Graz, Graz, Austria. §Associate Professor, Institute of Cell Biology, Histology, and Embryology, Medical University of Graz, Graz, Austria. ¶Full Professor and Head, Department of Oral Surgery and Radi- ology, Dental School, Medical University of Graz, Graz, Austria. Full Professor and Head, Institute of Cell Biology, Histology, and Embryology, Medical University of Graz, Graz, Austria. Drs Pekovits and Wildburger are listed alphabetically and con- tributed equally to this work. Address correspondence and reprint requests to Dr Wildburger: Department of Oral Surgery and Radiology, Dental School, Medical University of Graz, Auenbruggerplatz 12, Graz 8036 Austria; e-mail address: angelika.wildburger@medunigraz.at © 2012 American Association of Oral and Maxillofacial Surgeons 0278-2391/12/7001-0$36.00/0 doi:10.1016/j.joms.2011.07.019 154