Caroliene Meijndert

45 Performance of bone level implants with conical connections in the anterior maxilla Table 1. Characteristics of the study group at the start of the study. Mean age ± SD in years at implant placement 36.9±15.1 Sex (male/ female) 29/31 Implant location (I 1 /I 2 /C/P 1 ) 39 / 10 / 5 / 6 Implant diameter (3.3/4.1mm) 12 / 48 Implant length (12/14mm) 16 / 44 Augmentation before implant placement , n 29 mattresses (4-0 vicryl, Johnson & Johnson Gateway, Piscatatway, USA) (Raghoebar et al., 2009; Santing et al., 2013). The implants were placed three months thereafter (12 implants with 3.3 mm diameter and 48 implants with 4.1 mm diameter). This resulted in a population of 60 patients which could be divided in two subgroups and allowing to determine whether augmentation therapy influences the outcome compared to non-augmented sites. Implant placement All patients were scheduled to receive a bone level implant with conical connection (Straumann Bone Level Implant System, Institute Straumann AG, Basel, Switzerland). Individual surgical templates were provided to place the implants in the optimal position. In cases where parts of the implant shoulder remained uncovered, or where the buccal bone wall was thin (less than 2mm in thickness), a local augmentation procedure was performed with autogenous bone chips collected during implant bed preparation and anorganic bovine bone (Geistlich Bio-Oss®, Geistlich Pharma AG), covered with a Geistlich Bio-Gide® membrane (Geistlich Pharma AG). The wound was closed with Ethilon 5-0 nylon sutures (Johnson & Johnson Gateway, Piscataway, NJ, USA). All surgical interventions were performed under prophylactic antibiotics (amoxicillin 500 mg, three times daily, or clindamycin 300 mg, four times daily for 7 days in case of amoxicillin allergy) and patients were instructed to rinse with 0.2% chlorhexidine mouthrinse twice for 7 days. Implants integrated unloaded submucosally for 3 months. A removable partial denture was worn during this healing phase, but did not interfere with treated implant site. Prosthetic phase After the healing phase of 3 months, the implants were uncovered and a healing cap was placed for one week. A titanium-based provisional crown (temporary abutment 3