Inclusion Criteria:  - Age 20-70 years Indication of tooth replacement with implant-supported fixed dentures The test group should be without any potentially associated disease  pSS must be diagnosed according to the American-European Consensus Group criteria (Vitali et al., 2002):  The presence of any 4 of the following 6 items, as long as either item IV (Histopathology) or VI (Serology) is positive The presence of any 3 of the 4 objective criteria items (that is, items III, IV, V, VI)  The items:  I. Ocular symptoms: a positive response to at least one of the following questions:  Have you had daily, persistent, troublesome dry eyes for more than 3 months? Do you have a recurrent sensation of sand or gravel in the eyes? Do you use tear substitutes more than 3 times a day?  II. Oral symptoms: a positive response to at least one of the following questions:  Have you had a daily feeling of dry mouth for more than 3 months? Have you had recurrently or persistently swollen salivary glands as an adult? Do you frequently drink liquids to aid in swallowing dry food?  III. Ocular signs --that is, objective evidence of ocular involvement defined as a positive result for at least one of the following two tests:  Schirmer's I test, performed without anaesthesia (<5 mm in 5 minutes) Rose bengal score or other ocular dye score (>4 according to van Bijsterveld's scoring system) IV. Histopathology: In minor salivary glands (obtained through normal-appearing mucosa) focal lymphocytic sialoadenitis, evaluated by an expert histopathologist, with a focus score >1, defined as a number of lymphocytic foci (which are adjacent to normal-appearing mucous acini and contain more than 50 lymphocytes) per 4 mm2 of glandular tissue  V. Salivary gland involvement: objective evidence of salivary gland involvement defined by a positive result for at least one of the following diagnostic tests:  Unstimulated whole salivary flow (<1.5 ml in 15 minutes) Parotid sialography showing the presence of diffuse sialectasias (punctate, cavitary or destructive pattern), without evidence of obstruction in the major ducts Salivary scintigraphy showing delayed uptake, reduced concentration and/or delayed excretion of tracer  VI. Autoantibodies: presence in the serum of the following autoantibodies:  1. Antibodies to Ro(SSA) or La(SSB) antigens, or both  The control group should match the test group according to the age, sex and treatment region and fulfill the following: Normal salivary flow: unstimulated > 1.5 ml in 15 min, stimulated > 3.5 ml in 5 min No ocular or oral symptoms Submission of written informed consent form  Exclusion Criteria:  Persons with:  secundary Sjögren Syndrom (sSS) severe systemic disease including severe bleeding disorder and/or conditions which put the patient at risk and/or prohibit compliance as stated by Hwang and Wang, 2006; and Hwang and Wang, 2007): previous or present bisphosphonate, Denosumab or anti-angiogenetic chemotherapeutic drugs poor bone quality according to Lekholm U & Zarb GA (1985) or diagnosed osteoporosis Heavy smokers, eqv. to 20+ cigarettes/day Noncompliance