Gene expression and immunohistochemistry analysis of xenograft and allograft in maxillary sinus floor augmentation

Abstract

Quality of bone is an important factor contributing to the success of dental implants. The bone height in maxillary posterior area sometimes is not enough and might pose risks for placing dental implants. Maxillary sinus augmentation with bone substitutes is used for filling and correcting bony defects. This study aims to determine the differences in gene expressions of TNF-alpha, RUNX2, COL1A1, ALP between xenograft (Bio-Oss®) and allograft (SureOss®). Patients who needed two-stage maxillary sinus floor augmentation were included (n=13). Patient who had dental implant at posterior maxilla without bone substitutes was also used in immunohistochemistry analysis (IHC) (n=1). Bone samples were collected using trephine bur 2 mm internal diameter. Quantitative real-time PCR (qPCR) method was used for studying gene expression (n=10). Immunohistochemical staining of ALP was used to visualize the area of osteogenic activity (n= 4). The results of qPCR showed higher RUNX2 expression of allograft when compared to xenograft (p<0.05). Although, TNF-alpha, COL1A1 expression was not statistically different between groups. Immunohistochemistry staining of both samples also showed similar intensity and expression of ALP. The data suggested that gene expression levels of TNF-alpha and COL1A1 were not significantly different between bone grafted with Bio-Oss® and SureOss®. However, the expression of RUNX2 was significantly higher in SureOss®. Nevertheless, result from IHC study showed similar characteristics between both groups.