The study was performed according to the Declaration of Helsinki and internationally accepted guidelines for RCT, including the CONSORT statement (www.consort-statement.org). The volumetric changes of the augmented bone [26], the histological composition of the augmented bone [27] and pain after the primary bone augmentation procedure [28] were previously described in detail.

Patients

 

Eligible patients were randomly included (block randomisation with 20 patients in the first block and two patients in each of the following blocks) in a test (n = 14) and a control group (n = 13). Thus, a total of 27 consecutively treated patients (Table 1) were included according to the following inclusion criteria: (1) absence of one maxillary incisor, canine or premolar with indication for oral implant treatment, (2) severe atrophy of the alveolar process, classified as a type 2/4 defect by the “Classification of alveolar bone defects” by Terheyden [7] and hence potentially compromised primary stability with indication for lateral alveolar ridge augmentation before oral implant treatment, and (3) age > 20 years. The exclusion criteria were as follows: (1) systemic disease or medication compromising bone and soft tissue healing, (2) pathology in the edentulous region, (3) bruxism, (4) disease of the oral mucosa, (5) periodontal disease (probing depths ≥ 4 mm and a full mouth bleeding score ≥ 25%), (6) known allergies to bovine and porcine biomaterials and (7) no teeth adjacent the edentulous region.

The same surgeon (JH) at the Section for Oral Surgery and Oral Pathology, Department of Dentistry, Health, Aarhus University, Denmark, performed all surgical procedures between 2015 and 2017. Three highly trained prosthodontists at the Section for Prosthetics, Department of Dentistry, Health, Aarhus University, performed the prosthodontic procedures between 2016 and 2018. The mean age of the included patients at the time of inclusion was 48 years (range: 23–66 years) in the PRF group and 52 years (range: 24–72 years) in the control group (Table 1).