DOI: 10.11607/prd.3292, PubMed ID (PMID): 29897351Pages 227-232, Language: EnglishCrespi, Roberto / Capparé, Paolo / Crespi, Giovanni / Gastaldi, Giorgio / Romanos, Georgios E. / Gherlone, EnricoThe aim of the present study was to consider the long-term midfacial mucosal outcome around final prosthetic restorations on dental implants placed and loaded immediately after tooth extractions. A total of 42 patients requiring tooth extractions were recruited, and 142 teeth were extracted. Based on the amount of keratinized mucosa (KM), implants were categorized into group A (KM ≥ 2 mm; n = 61) or group B (KM 2 mm; n = 62). In both groups, all patients received temporary prosthetic restorations immediately after the surgical procedure. Baseline levels were measured at placement of the final prosthetic restoration and patients were followed for 8 years. After the 8-year follow-up, a survival rate of 98.37% was reported. Two implants were lost due to peri-implantitis after 6 and 7 years of function, respectively. Peri-implantitis occurred at 9 implants (3 from group A and 6 from group B) in 8 patients (7.32%). At the 8-year followup for group A, an increase in midfacial tissue level of 0.14 ± 0.13 mm (screwed restorations) and 0.16 ± 0.09 mm (cemented restorations) was measured. For group B, a decrease in midfacial tissue level of 0.15 ± 0.09 mm (screwed restorations) and 0.17 ± 0.12 mm (cemented restorations) was reported. Statistically significant differences between groups were measured at 2, 5, and 8 years of follow-up (P .01). The results demonstrated that the presence of KM is significantly associated with less mucosal inflammation and less gingival recession, regardless of the type of prosthetic restoration (screwed vs cemented).