Implantology and Sjögren's Syndrome

Inclusion criteria (dentate group, Sjögren): * The patient is at least 18 years and younger than 70; * A diagnosed (by the AECG guidelines; see attachment; Vitali et al., 2002) primary or secondary Syndrome of Sjögren; * The missing or lost tooth/teeth are premolars and/or molars in the upper or lower jaw. * Sufficient healthy and vital bone to insert a dental implant with a minimum length of 8 mm and at least 3.8 mm in diameter. In case of insufficient bone volume, a bone augmentation procedure will be performed with autologue bone. If necessary the autologue bone can be mixed with artificial bone (artificial bone graft substitutes in combination with a membrane). * The implant site must be free from infection; * Adequate oral hygiene (modified plaque index and modified sulcus bleeding index ≤ 1) (Mombelli et al., 1987; Loe and Silness, 1963) * Sufficient mesio-distal, bucco-lingual, and interocclusal space for placement of an anatomic restoration; * The patient is capable of understanding and giving informed consent. Inclusion criteria (edentulous group, Sjögren): * The patient is at least 18 years and younger than 70; * A diagnosed (by the AECG guidelines; Vitali et al., 2002) primary or secondary Syndrome of Sjögren * The patient is edentulous. Before final inclusion in the study the patient has to be edentulous for 1 year. * Problems with conventional denture retention, stability and/or adaptation, which could be solved by an implant, supported denture (lower or/and upper jaw). * Sufficient healthy and vital bone to insert dental implants with a minimum length of 8 mm and at least 3.8 mm in diameter. In case of insufficient bone volume, a bone augmentation procedure will be performed with autologue bone. If necessary the autologue bone can be mixed with artificial bone (artificial bone graft substitutes in combination with a membrane). * The implant site must be free from infection; * Capable of performing adequate oral hygiene; * The patient is capable of understanding and giving informed consent. Inclusion criteria control groups: \- The inclusion criteria for the healthy control groups are similar as for the Sjögren groups without the Sjögren criterion. Exclusion criteria: Criteria used for excluding patients from this study are as follows: * Medical and general contraindications for the surgical procedures; * Presence of an active and uncontrolled periodontal disease as expressed by probing pockets depths \> 4mm with bleeding upon probing; * Smoking (patients who stop smoking six weeks before the operation can be included); * A history of radiotherapy to the head and neck region; * Use of intravenous bisphosphonates or the use of oral bisphosphonates for more than 5 years.