**5. Conclusions**

In this study, most of the significantly genes belonging to the "extracellular matrix proteases" pathway were up-regulated. These results seem to indicate that amlodipine has an effect on the modulation of fibrosis response in gingival fibroblasts, up-regulating extracellular matrix proteases, and favouring the deposition of fibrotic tissue. More explanatory results could probably be obtained by using gingival fibroblasts in which the use of amlodipine seems to aggravate the fibrotic response and the gingival overgrowth.

GOIA is no longer a rare occurrence. From one side, plaque accumulation is an inevitable consequence of GOIA, and from the other, it favours gingival inflammation and overgrowth. The duration of therapy, dosage, and individual genetic susceptibility are considered important risk factors for the development of GOIA. Amlodipine is a widely used drug for the treatment of hypertension and angina, so it is very important that doctors inform patients about side effects, such as GOIA, and about the importance of preventive protocols. Dentists should be able to identify the changes in the oral cavity that are related to the general health of their patients. The patients must be informed of the tendency of certain drugs to cause gingival overgrowth and the associated oral changes and the importance of effective oral hygiene.

Combination therapy consisting of surgical and non-surgical periodontal therapy with drug substitution is the most reliable method in the managemen<sup>t</sup> of GOIA.

**Author Contributions:** Conceptualization, D.L.; Data curation, A.L. and F.C. (Francesca Cura); Investigation, D.D.S.; Supervision, F.C. (Francesco Carinci); Visualization, F.D.V.; Writing—review & editing, A.P.

**Funding:** This research received no external funding.

**Conflicts of Interest:** All authors declare they have no conflict of interest.
