After patient screening was performed, 30 implants in the premolar and molar regions of the upper jaw in 14 patients met the inclusion criteria and were clinically and radiologically followed up according to the study protocol. The aim of the follow-up investigation was to analyze whether implants of 7-mm length are suitable for prosthetic rehabilitation in the atrophic maxilla to avoid a sinus augmentation procedure.

After a mean loading period of 5-years, all 30 implants were in situ and suitable for prosthetic rehabilitation (survival rate of 100%). All implants were stable without signs of mobility. Twenty-one implants were restored with cement-retained fixed crowns, while 9 implants were restored with removable superstructures. Removable superstructures have been restored with electroplated telescopic crowns and have therefore not been primary splinted. Also, the majority of fixed superstructures (17) have been un-splinted single crowns, while only 4 implants in 2 patients have been restored with splinted single crowns. No major complications during healing and loading were recorded.

Analysis of the width and thickness of peri-implant keratinized gingiva indicated a mean peri-implant keratinized gingiva thickness of 1.8 mm (1–3 mm) and peri-implant keratinized gingiva width of 2.0 mm (1–3 mm). Gingival recessions of 1 mm at the facial contour were detected in 4 implants, which led to exposition of the implant shoulder.

Measurements of the PPD were recorded at four sites per implant (mesio-buccal, disto-buccal, mesio-oral, and disto-oral) and indicated a mean PPD of 2.5 mm (1–5 mm). The inflammatory conditions of the peri-implant tissue, which were analyzed by recording bleeding after measuring the PPD, indicated BoP in 4 of the 30 implants, so the BoP ratio was 13.3%. A distinct correlation between an increased PPD and increased BoP was shown, as the BoP was recorded at most implants presenting with PPDs of more than 4 mm. The entire clinical follow-up investigated revealed no impact of prosthetic restorations (fixed or removable, splinted or un-splinted prosthetics) on per-implant soft-tissue health.