and 1 other(s)
Background Extraction of posterior maxillary teeth can result in severe bone resorption, which may preclude the placement of dental implants. Traditionally, techniques involving bone graft material are used to overcome this loss of bone volume. Less invasive and more cost-effective graft-less procedures have also been shown to be clinically effective. Here, we evaluated a new implant design in graft-less sinus floor elevation using both lateral and crestal approaches. Aim In this open prospective clinical study, we investigated the clinical performance of a new reverse spiral flute implant design (Nobel Biocare AB, Gothenburg, Sweden) used in lateral and crestal graft-less sinus floor elevation protocols. One-year outcomes are presented. Materials and Methods Patients seeking implant-supported restoration of the posterior maxilla and requiring sinus floor augmentation with a residual bone height less than 8 mm at implant site were included. Implants were placed using either a lateral or crestal graft-less sinus floor elevation protocol. Crestal at residual bone height of 6 to 8 mm, Lateral in bone heights less than 6 mm. The new implant design features an anodized surface, a rounded apex and a sharp cutting flute oriented in the opposite direction of the implant threads with the aim to deliver bone chips into the sinus cavity to facilitate new bone formation. Implants were placed in healed sites and loaded with screw-retained temporary fixed restorations after 6 months of submerged healing. Final restorations were placed after 2 months of function. Clinical and radiographic data including implant and patient level cumulative survival rate (CSR), implant stability quotient (ISQ), and implant complications were assessed at regular intervals. Results 132 implants were placed in 60 patients of both sexes with a mean age of 58 years. In 40 patients, 98 were placed with the lateral technique and in 20 patients, 34 implants with the crestal one. At 1 year follow up 3 implant failed, 2 in the lateral and 1 in the crestal group. CSR was 97.7% at implant level and 95.0% at patient level. All surviving implants were stable at the 1year follow up (n=129). For the resonance frequency analysis, mean ISQ values were 66.4, 74.5 and 79.1 for the lateral approach and 75.3, 80.7, and 84.0 for the crestal approach at implant placement, at 6- and 8-month follow-ups, respectively. The sinus membrane was accidentally perforated during the sinus elevation procedure in 12 patients. In another 6 patients the perforation was on purpose due to simultaneously removal of intra sinusal cysts. No perforations were caused from implant insertion. Radiographic analysis of 3D bone remodeling is currently ongoing and will be reported at the time of presentation. Conclusions In situations of severe bone resorption in a pneumatized maxilla, the reverse spiral flute implant has excellent stability, indicated by increasing ISQ values at subsequent follow-ups, and good survival rates after 1 year of function when placed using a graft-less lateral or crestal sinus floor elevation protocol.
No datasets are available for this submission.
No license information is available for this submission.