Matrix metalloproteinases 2, 3, 8, 9, and 13 in the peri-implant soft tissues around titanium and zirconium oxide healing caps.

and 13 in the soft tissues around titanium and zirconium oxide healing caps. MATERIALS AND METHODS: Five patients participated in this study. All patients received 3.8 × 11-mm dental implants, which were left to heal in a nonsubmerged (single-stage) mode. Healing caps (3.8 mm in diameter and 3.0 mm in height) were inserted in all implants. Half of the implants were randomly supplied with standard, prefabricated caps of commercially pure titanium (control), while the other half were randomly provided with zirconium oxide caps (test). After a 6-month healing period, gingival biopsy specimens were obtained with a circular scalpel around the healing caps of both groups, without unscrewing or removing the healing caps, and the samples underwent immunohistochemical processing for MMPs 2, 3, 8, 9, and 13. RESULTS: Statistically significant differences were found in the values of MMP-8 in the cells of the inflammatory infiltrate, with higher values for the titanium samples. Statistically significantly higher values were found, also in the titanium samples, for MMP-9 in the endothelial cells of the blood vessels. No statistically significant differences were found for any other MMPs.