Retrospective study on transcrestal sinus floor elevation with simultaneous implantation of short implants / 华西口腔医学杂志

OBJECTIVE@#To explore the changes in bone height of the maxillary sinus floor at different sinus ridge heights after transcrestal sinus floor elevation (tSFE) with the simultaneous implantation of short implants.@*METHODS@#A total of 74 Bicon short implants were implanted into 37 patients during the same period of maxillary sinus elevation. The residual bone height (RBH)<4 mm group has 43 sites, and the RBH≥4 mm group has 31 sites. After 5 years of follow-up observation, the implant survival rate and the change in bone height achieved in the maxillary sinus over time were measured and analyzed via clinical examination and X-ray imaging.@*RESULTS@#In the 74 implantation sites, the elevation height of the sinus floor was (6.64±1.32) mm and the bone height of the sinus floor was (3.35±1.29) mm 5 years after loading. No statistical difference was observed in the bone resorption of the implant neck between the RBH<4 mm and RBH≥4 mm groups. Meanwhile, a statistical difference was noted in the bone height obtained in the maxillary sinus between the two groups.@*CONCLUSIONS@#When RBH in the maxillary posterior tooth area was <4 mm, the simultaneous implantation of Bicon short implants with tSFE can achieve a high implant survival rate and bone gain in the maxillary sinus, but does not increase the absorption of the alveolar ridge bone.

A photoelastic stress analysis of fixed partial dentures with bicon implants on mandibular posterior area / 대한치과보철학회지

STATEMENT OF PROBLEM: Several prosthetic options are available for the restoration of multiple adjacent implants. A passively fitting prosthesis has been considered a prerequisite for the success and maintenance of osseointegration. Passivity is a particular concern with multiple implants because of documented inaccuracies in the casting and soldering process. One way to avoid this problem is to restore the implants individually, however, the restorations of individual adjacent impants requires careful adjustment of interproximal contacts. PURPOSE: The purpose of this study was to compare the stress distribution pattern and amount surrounding Bicon implants with individual crowns and splinted restorations. MATERIAL AND METHOD: A photoelastic model of a human partially edentulous left mandible with 3 Bicon implants(4*1 mm) was fabricated. For non-splinted restorations, individual crowns were fabricated on 3 abutments (4.0*6.5 mm, 0 degree, 2.0 mm post, Bicon Inc., Boston, USA) After the units were cemented, 4 levels of interproximal contact tightness were evaluated: open, ideal (8 micrometershim stock drags without tearing), medium(40 micrometer), and heavy(80 micrometer). Splinted 3-unit fixed partial dentures were fabricated and cemented to the model. Changes in stress distribution under simulated non-loaded and loaded conditions(7.5, 15, 30 lb) were analyzed with a circular polaricope. RESULTS: 1. Stresses were distributed around the entire body of fin in Bicon implants. 2. Splinted restorations were useful for distribution of stress around implants especially with higher loads. 3. By increasing the contact tightness between the individually restored three implants, the stress increased in the coronal portion of implants. CONCLUSIONS: Ideal adjustment of the contact tightness was important to reduce the stresses around individually restored Bicon implants.