Analysis of MMP-1 and MMP-9 Promoter Polymorphisms in Early Osseointegrated Implant Failure

Purpose: Polymorphisms, such as a guanine inserted at position -1607 in the promoter region of human matrix metalloprotenase 1 (MMP-1) or a C-1562T substitution in the MMP-9 gene, have been shown to increase the transcriptional activity of these MMPs. The objective of this study was to investigate the possible relationship between these polymorphisms and early implant failure. Materials and Methods: Genomic DNA from oral mucosa was amplified by polymerase chain reactions (PCRs) and analyzed by restriction endonucleases. The significance of the differences in observed frequencies of polymorphisms was assessed by the chi-square and Fisher exact tests. Results: The test group comprised patients with early failure of osseointegrated oral implants. In the MMP-1 gene, 2G allele was observed in 25% of the control group and in 50% of the test group (P = .013). The genotype 1G/1G was found in 61.5% of the control group, while all patients in the test group had the genotype 1G/2G (P .001). No differences were seen in the allele and genotype frequencies in the MMP-9 gene among the groups (P = .15 and P = .13, respectively). Discussion and Conclusion: These results suggest that polymorphism in the promoter region of the MMP-1 gene may be associated with early implant failure, while polymorphism in the promoter region of the MMP-9 gene may not have a relationship with implant loss.