Can mesenchymal stem cells and novel gabapentin-lactam enhance maxillary bone formation?

Novel gabapentin-lactam (GBP-L) has shown its potency in enhancing new bone formation (NBF) in vitro. The objective of the present preclinical trial was to investigate the in vivo performance of GBP-L.

Bilateral sinus floor augmentations in 10 adult sheep were conducted. Bovine bone mineral (BBM) and mesenchymal stem cells (MSCs) combined with novel GBP-L were placed into the test sinus of each sheep. The BBM and MSCs alone served as the control on the contralateral side. Simultaneously, 3 dental implants were inserted in each maxillary sinus. The animals were sacrificed after 8 and 16 weeks, and the amount of NBF was analyzed using histomorphometry. The osteogenic potency of the MSCs was demonstrated using the colony-forming unit and differentiation assay. Statistical evaluation was performed using the Wilcoxon signed rank test and 3-factorial nonparametric analysis of variance.

The histologic examination showed NBF in tight contact with the original bone in the control and test groups. The NBF was not significantly different between the test and control sites (P > .05). However, a highly significant difference in NBF between the apical and coronal sites in the specimens from the control and test groups was detected (P < .05). GBP-L did not alter the multipotency of the MSCs or impair NBF.

Bone formation is initiated from the residual alveolar crest and along the implant. The elected mode of GBP-L application did not induce faster NBF. Alternate forms of application (eg, slow release or systemic administration) might clarify the controversial in vitro findings.