Genetic Polymorphism and Expression of Matrix Metalloproteinases and Tissue Inhibitors of Metalloproteinases in Periapical Lesions: Systematic Review

Introduction: Recent studies involving genetic polymorphism and expression have provided information about their role in periapical lesions. This study aimed to evaluate if there is an association between the genetic polymorphism and gene and protein expressions of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in the periapical inflammatory response. Methods: A systematic review was conducted through a rigorous search in electronic databases as well as a hand search. Two reviewers (kappa = 0.90) evaluated the studies considering predetermined eligibility criteria, extracted data for interpretation, and finally used the Strengthening the Reporting of the Genetic Association statement to determine the quality of the scientific evidence. Results: The initial search identified 251 studies. After excluding the duplicates and applying the eligibility criteria, 15 studies were eligible to be assessed in full. Two studies had grade A and 13 grade B quality according to the Strengthening the Reporting of the Genetic Association and were included. The selected studies showed that the periapical lesion tissue samples had a high concentration of MMPs; moreover, there was an expressive decrease in the concentration of MMPs and TIMPs in patients with periapical lesions after mechanical chemical preparation. In relation to genetic polymorphisms, MMP1, MMP2, MMP3, and MMP8 were associated with a higher risk of periapical lesions. Moreover, MMPs 1, 2, 3, 7, 8, 9, 13, 14, 16, and 25 and TIMP 1, 2, 3, and 4 can play an important role in the progression of periapical lesions. Conclusions: Based on articles with medium to high quality, MMPs and TIMPs are associated with the formation of periapical lesions.