Background: Sinus augmentation is a common procedure to increase bone volume and allow for proper implant placement in the atrophic posterior maxilla. Although the patient's own bone is considered the best grafting material, various synthetic or bovine-derived alternatives are used to simplify the grafting procedure.

Immediate full-arch rehabilitation yeilds an instant significant improvement in general patient satisfaction and self-perceived factors related to comfort, function and esthetics. Eating comfort is the main concern for the patient and shows the highest improvement. Postoperative complications are limited and patients considered immediate loading important.

The implant and prosthetic survival was 100%, and patients benefited from the All-on-4 treatment. However, unacceptable ongoing bone loss was seen in 49.2% of the patients; this may be a warning sign for future problems and needs clinical attention. Overloading and surgery-related aspects need to be investigated as potential explanations.

The purpose of this controlled study was to determine the impact of a single-tooth implant, fixed implant prosthesis and completely removable dental prosthesis on intelligibility, articulation and oromyofunctional behaviour. Additionally, the self-perceived overall satisfaction of the dental replacements and the effect on speech was questioned. Objective (acoustic analysis) as well as subjective assessment techniques (perceptual evaluation) were used. The satisfaction of single-tooth implant group was very high (100%) followed by a satisfaction of 87% for the fixed implant prosthesis group and 68% for the removable prosthesis group. The results of the phonetic analyses revealed a normal intelligibility and oromyofunctional behaviour in the three groups of dental replacements. Only one type of articulation disorders was observed in the single-tooth implant group, followed by three types of disorders in the removable prosthesis group and six types of disorders in the fixed implant prosthesis group. In this last group, not only 87% of the subjects showed distortions of one or more consonants but also most consonants of the Dutch language were disturbed in comparison with the single-tooth implant and removable prosthesis users. Special attention must be paid to the fricative /s/ because in more than 50% of all groups, this sound is disturbed.