Osseointegrated implant failure associated with MMP-1 promotor polymorphisms (-1607 and -519)

Two polymorphisms in the promoter region of human MMP-1 gene, an insertion of a guanine at position -1607 and A-519G substitution, have been shown to increase the transcriptional activity of these matrix metalloproteinases (MMPs). The objective of this study was to investigate the possible relationship between these polymorphisms and early implant failure.

A sample of 104 nonsmokers was divided into 2 groups: a test group comprising 44 patients with 1 or more early failed implants and a control group consisting of 60 individuals with 1 or more healthy implants. Genomic DNA from oral mucosa was amplified by polymerase chain reaction and analyzed by restriction endonucleases. The significance of the differences in observed frequencies of polymorphisms were assessed by chi2 tests.

The G-1607GG polymorphism with the genotype G/G was observed at a frequency of 62% in the control group, while in the test group this genotype was noted in 34% of the individuals (P = .011). The allele G was found at a frequency of 75% in control group and 61.66% in the test group (P = .05). No significant differences were seen in the genotypes and allele frequencies in the A-519G polymorphism among the groups (P = .064 and P = .124, respectively). The distribution of the haplotypes arranged as alleles and genotypes showed a significant difference between control and test groups (P = .031 and P = .002, respectively).

On the basis of this study of 60 patients who experienced no implant failure and 44 patients who experienced implant failure, the results suggest that G-1607GG polymorphism in MMP-1 gene is associated with early implant failure, while A-519G polymorphism in MMP-1 gene does not show a significant relationship with implant loss. This study also suggests that haplotypes G-1607GG and A-519G of MMP-1 may be associated with the osseointegration process.