Clinical and histological comparison of the soft tissue morphology between zirconia and titanium dental implants under healthy and experimental mucositis conditions—A randomized controlled clinical trial.

Objectives: To analyse the soft tissue morphology under healthy and experimental mucositis conditions comparing zirconia and titanium implants. Methods: Forty‐two patients with two adjacent missing teeth received one zirconia (Zr) and one titanium (Ti) implant, with the mesial and distal position randomized. At 3 months, half of the patients were instructed to continue (healthy; h) and the other half to omit (experimental mucositis; m) oral hygiene around the implants for 3 weeks. Clinical parameters were evaluated before and after the experimental phase, and a soft tissue biopsy was harvested. Mixed model analyses were performed to analyse the data. Results: The plaque control record increased significantly for the two mucositis groups, reaching 68.3 ± 31.9% (mean ± SD) for Zr‐m and 75.0 ± 29.4% for Ti‐m (p <.0001), being also significantly lower for Zr‐m than for Ti‐m. Bleeding on probing remained stable in group Zr‐m and amounted to 21.7 ± 23.6%, but increased significantly in group Ti‐m (p =.040), measuring 32.5 ± 27.8%. The number of inflammatory cells and the length of the junctional epithelium did not significantly differ between the groups. Conclusion: Both implants rendered similar outcomes under healthy conditions. Lower plaque and bleeding scores were detected for zirconia implants under experimental mucositis conditions. Histologically, only minimal differences were observed. [ABSTRACT FROM AUTHOR]