Behaviour of bioactive glass (S53P4) in human frontal sinus obliteration

A prospective study was carried out on bioactive glass (BG) as an obliteration material in a series of osteoplastic frontal sinus operations on 22 patients. Preoperative examinations and postoperative follow-ups included plain films, computed tomography (CT), magnetic resonance imaging (MRT) and laboratory monitoring. The follow-up visits were scheduled at 3, 6, 12 months and 2, 3 and 4 years. No complications related to the obliteration material were observed. All wounds healed well without signs of infection. The repair of defects filled with BG granules was closely monitored with repeated postoperative digital ROI selection of CT tomography image areas. Plain films and CT revealed no resorptive changes at the BG-bone interfaces. Contrast enhanced MRI indicated ingrowth of fibrovascular tissue in spaces between the granules. ROI selection showed minor changes during the first year. Thereafter, the BG-bone interface remained stable. Two sinuses were explored one year postoperatively, and the retrieved specimens were evaluated histologically. The spaces between the BG granules were filled by fibrous tissue and in some areas by immature bane. The granules were partly incorporated with bone and with fibrous tissue. No inflammatory reactions, lymphocytes or granulocytes, were observed. All laboratory tests were within the normal range during follow-up. No infections were seen and no reoperations were necessary in our (22) obliteration cases.