Caroliene Meijndert

87 Alvoalar ridge preservation in defect sockets in the maxillary aesthetic zone Insufficient labial bone wall thickness at implant placement In all cases there was enough bone volume after alveolar ridge preservation to insert the implant with sufficient primary stability. The thickness of labial bone wall at implant placement was <2 mm in 10 cases. In 5 of these cases the alveolar ridge preservation was previously done with bone from the maxillary tuberosity, whereas in the other 5 cases bone was harvested from the retromolar area. Implant stability Mean implant stability immediately after implantation was 68.9±8.74 ISQ and 80.2±2.73 ISQ just before placement of the definitive restoration. Survival rate One patient lost the implant two months after placement. This resulted in an implant survival rate of 96.7%. The patient was excluded from further analysis ( Table 2 ). Table 2. Survival rate (%) and bone level change from 1 month (T 1 ) to 12 months (T 12 ) after definitive restoration placement measured in mm, with the median [IQR] and mean±SD depicted in the parentheses. Implant loss, n (survival rate %) 1 (96.7%) Bone level change Mesial 0.00 [-0.04;0.00] (-0.07±0.16) Distal 0.00 [-0.02;0.00] (-0.06±0.14) Mesial+distal 0.00 [-0.08;0.00] (-0.07±0.12) Peri-implant bone level change The main results are depicted in Table 2. There was statistically no significant changes from T 1 to T 12 ( Figure 1 ). The peri-implant bone level changes were not normally distributed, so only the medians and IQR were calculated. To give more insight in the actual change, bone level changes are also depicted in mean±SD. The mean bone level change was -0.07±0.16 mm on the mesial side and -0.06±0.14 on the distal side. 5