If radiographic and clinical examination alone are used for pulp diagnostics, the inflammatory state of the pulp may be misdiagnosed.18,22 Following the suggestion by Wolters et al43 to differentiate between more stages of pulpal inflammation than reversible and irreversible pulpitis based on clinical and radiographic findings, MMP-9 measurements could help to determine the exact grade of pulpal inflammation. This evidence concerns the gene MMP9 and pulpitis.