IM0410

I user report _ oroantral communications Figs. 9a & b_Complete soft tissue closure, lateral view after 3 (left) and 8 months (right). Fig. 10_Radiograph after OAC-closure. ventadisplacementofthegraftmaterialintothenasal cavity. Only after the formation of a stabilized coagu- lum the socket was filled with a fully synthetic bone graft substitute (easy-graft®, Degradable Solutions AG,Schlieren,Switzerland)tothegingivalevel.Thema- terialconsistsofporous -TCPgranulesthatarecoated with a 10 µm thin film of a polylactide. By mixing the granulate in the syringe with a liquid plasticizer, the polymer layer is softened and the granulate is trans- formed into a moldable mass. Excess liquid has to be discardedpriortograftapplicationbypressingitcare- fully into a sterile swab. The bone graft substitute was applied directly from the syringe into the defect. In cases of larger perforations, the putty-like mass was flattened at its front end in order to prevent compres- sion or displacement of the cellulose-stabilized coag- ulum (Fig. 3). The bone substitute was pressed gently into the defect and adapted to the socket walls with a sharpspoon(Fig.4).Theputty-likematerialhardensin contact with blood and other aqueous liquids into an inherently stable, porous, defect-analog body within minutes(Fig.5).Thesofttissuewasnotsutured.Com- plete closure of the communication was verified by askingthepatientstopressurizehisorhernasalcavity. Defectfillingwasassessedradiographically.Inorderto minimize pressure onto the implant material, the pa- tientswereadvisednottoblowtheirnoseatthedayof theoperationandtoeatwithcareinordernottoputa mechanicalstrainonthedefectsite.Sixpatientstooka broad-spectrumantibioticduring3to8days;theother threepatientsdeclinedtheuseofantibioticsforantibi- oticprophylaxis(Table2). _Follow-up Recallappointmentswerescheduledafteroneday, seven days, two weeks and five weeks. More appoint- ments were fixed if the medical situation demanded closemonitoringofthepatient.Onepatientdidnotap- pear for the one-week control, two patients were not available for the two- and the five-week controls. All patientswereseenatleastoncebetweenweekoneand weektwo,andallbutonepatientwerefollowedupfor fourweeksormore.Oroantralcommunicationclosure, healing and clinical outcome were documented pho- tographically and radiographically. In one case, soft andhardtissuesamplestakenduringtheplacementof a dental implant were subjected to histological analy- sis. _Results Occurrenceoforoantralcommunications Mostly, the oroantral communications have oc- curred after extraction of the first molar (4/9), two oroantralcommunicationswereopenedupduetoex- traction of the second molar, the remaining three oroantral communications were observed after re- moval of a first and a second premolar and a wisdom tooth,respectively. Surgeryandhealing The graft material hardened within minutes to an inherentlystablebodyintheextractionsocket.Allsub- jects were able to pressurize the nasal cavities, which indicatedacompleteclosureoftheperforation.Thepa- tientsreportedweakpainonthefirstdayaftertheop- eration and a weak sensation of warmth in the region where the perforation has been closed. Swelling was not observed in the operated region in any of the pa- tients.Bloodynasaldischarge,whichwouldbeasignof bleeding into the nasal cavity, was not observed. The bone graft substitute material formed a stable block that was well adapted to the wound contours. The -TCP composite swells slightly due to water uptake. Thegraftwasthustightlyfixedintheextractionsocket and protruded slightly above the gingiva level (Fig. 6). Withintwoweeks,thegraftmaterialwascoveredwith softtissue.Single -TCPgranuleshavebeenintegrated into the covering tissue layer (Fig. 7). The vertical di- mensionofthematerialdecreasedduetotheongoing degradation procedure. However, the material always remained at the height of the biological width. After four to six weeks, a complete regeneration of the soft tissue could be observed. A collapse of the alveolar ridge could be prevented. After nine months, the ini- tially convex buccal plate has receded slightly and ap- peared straight in the occlusal view (Figs. 7 & 8), indi- catingamarginalreductioninthewidthofthealveolar ridge. Nevertheless, the vertical and horizontal dimensions of the well-attached gingiva were main- tainednearlycompletely(Fig.9). 34 I implants4_2010 Fig. 9b Fig. 10Fig. 9a