After an average time in situ of 41.2 ± 27 months (3.4 years; range 0–96 months), 40 of the 863 implants were lost. These results indicated an in situ rate of 95.4%. One-year and five-year survival rate according to Kaplan–Meier were 95.4 and 94.4%. In patients receiving an external sinus lift an in situ rate of 95.1% and in patients with an internal sinus lift an in situ rate of 96.4% after the mean follow-up of 3.4 years was achieved. These results indicated a higher survival rate for the internal sinus lift procedure, but this difference was not statistically significant (p = 0.614, Fig. 2). The in situ rates were 100% for implants with a length <10 mm, 95.3% for implants with a length 10–13 mm, and 93.9% for implants with a length >13 mm. These differences were not statistically significant (p = 0.657). Implant survival for implant diameter <3.6 mm were 100%, for implant diameter 3.6–4.5 mm 96.0%, and for implant diameter >4.5 mm 92.2%, indicating a not statistically significant difference (p = 0.123). For patients that were available for clinical follow-up examination, the plaque index showed that 86.6% of implants had a satisfactory degree of oral hygiene (grades 0 and 1). Concerning the gingival index, 76.4% of the implants showed a gingival index grade 0, 19.7% a gingival index grade 1, and 3.8% a gingival index grade 3. A probing depth of less than 3.5 mm at all four measured sites around each implant was determined for 82.8% of the implants. The width of keratinized mucosa was <1 mm in 38.9% of the implants, between 1 and 2 mm in 37.6% of the implants, and >2 mm in 11.4% of the implants. No keratinized mucosa was found in 12.1% of the cases.

In 182 patients, pre- and post-treatment oral health-related quality of life after sinus augmentation procedure using a standardized questionnaire was evaluated. Subcategories for this evaluation were (1) functional limitations, (2) physical and psychological disabilities, and (3) complaints due to the surgical procedure.