GENE EXPRESSION OF ALVEOLAR BONE WITH MAXILLARY SINUS FLOOR AUGMENTATION USING XENOGRAFT

Abstract

A lack of alveolar bone in the maxillary sinus area often causes difficulty in placing implants. Alveolar bone resorption and sinus pneumatization may occur after maxillary posterior tooth extraction. An adequate quality and quantity of bone is important for successful implant placement. Therefore, maxillary sinus floor augmentation (MSFA) using different types of grafts is performed when the amount of alveolar bone is insufficient. Histologic, and histomorphometric studies and systematic reviews have shown the clinical success of the use of anorganic bovine bone (ABB, Bio-Oss®) in maxillary sinus floor augmentation (MSFA). The molecular processes involved in bone healing are, however, still unclear. To explore gene expression associated with bone remodeling and inflammation, the mRNA expression levels of RUNX2, RANKL, OPG, MMP-9, TRAP, and IL-1β, as well as the ratio of RANKL/OPG were compared between alveolar bone of a group after MSFA with ABB and a maxillary posterior edentulous bone group. Seven bone samples from each group were collected at the time of implant placement, after 6 months of MSFA or tooth extraction. Real time RT-PCR was used to analyze gene expression. Real time RT-PCR revealed no statistically significant difference in gene expression level of RUNX2, RANKL, OPG, MMP-9, TRAP, and IL-1β, and in the ratio of RANKL/OPG. After a healing period of 6 months, ABB particles do not have an effect on the expression of genes associated with bone remodeling and inflammation.