Immediate loading versus immediate provisionalization of maxillary single-tooth replacements: a prospective randomized study with BioComp implants.

PURPOSE: The aim of this prospective randomized study was to evaluate the clinical outcome of immediately loaded solid plasma sprayed (TPS) BioComp (BioComp Industries BV, Vught, The Netherlands) implants versus immediate provisionalized but non-loaded BioComp implants in the anterior and premolar region of the maxilla.

MATERIALS AND METHODS: Forty-eight patients (31 females and 17 males) with a mean age of 42.3+/-13.1 years (range 19 to 78 years) were included in the study. Fifty threaded TPS implants were placed and provisionalized within 24 hours after surgery. The patients were randomly assigned to 2 groups. In the immediate loaded (IL) group (n=24) the occlusion of the provisional was designed with normal contacts in centric relation and at lateral excursions, while in the non-immediate loaded (IP) group (n=24) the provisional restoration was adjusted to clear all occlusal contacts or contacts at lateral excursions. Patients were instructed to eat a soft diet and to avoid placing food in the area of the provisional crown during the first 6 weeks. Regular clinical and radiographic controls were performed and the survival rate and implant stability quotient (ISQ) values were evaluated at delivery of the definitive restoration at 6 months. At 1 year, radiographic coronal bone defects and gingival esthetics between the 2 groups were assessed.

RESULTS: Of the IL group, 2 fixtures were lost, while 3 implants were lost in the IP group. The failing implants showed increasing mobility at 2 to 3 weeks after insertion, and were removed. The remaining 45 implants were stable at every subsequent follow-up examination, and 6 months after implant placement, ISQ values were measured. The mean ISQ value in the IL group was 63.7+/-5.8 versus 63.2+/-4.3 for the IP group (P=.78). The mean mesial marginal bone loss after 12 months in the IL group was 0.27+/-0.2 mm versus 0.28+/-0.22 mm in the IP group (P=.9). The mean distal marginal bone loss after 12 months in the IL group was 0.19+/-0.15 mm versus 0.2+/-0.11 mm in the IP group (P=.87). All implants of the IL group had an ideal gingival buccal margin, versus 91% of the IP group. Full regeneration of the mesial interdental papilla was observed in 70% of the IL group versus 91% of the IP group, while full regeneration of the distal papilla was observed in 91% of both the IL and IP implants.

CONCLUSION: No significant differences in ISQ mean values in radiographic bone loss and gingival esthetics were found between immediate non-loaded provisionalization and immediately loaded BioComp implants in the maxilla.