Two-Step Progressive Transcrestal Sinus Augmentation Using a 4.5 mm Unloaded Implant as a "Temporary Implant" in Highly Atrophic Ridge: Case Report

Abstract

Severe atrophic posterior maxillary ridge (residual bone height < 3 mm) could be a challenging situation to place dental implants. Several treatment options have been proposed, but some of them may require advanced surgical skills to achieve best results. In this article, we present a novel and easier technique to allow implant placing in localized areas of severe atrophy. In a first step, a 4.5-length extra-short (unloaded) implant is placed after a transcrestal maxillary sinus floor augmentation (MSFA). After the gained apical bone consolidation, this "temporary implant" is atraumatically removed and a longer and wider definitive implant is placed to support the definitive single restoration. The case of a 45-year-old female treated with this approach is also presented. The patient suffered a severe resorption in the upper right molar area after a tooth extraction. Four months after the "temporary implant" placement and MSFA grafting with plasma rich in growth factors and autologous bone, 3 mm of dense apical bone gain could be observed. In a second surgical time, the 4.5 mm-length "temporary implant" was removed, and a 5.5 mm-length "definitive implant" was placed. This second implant was placed in a denser type 1 (1,000 Hounsfield Unit) new formed apical bone. Four months later, the implant was loaded with a screw-retained crown over a transepithelial (intermediate abutment). After 1-year follow-up, the implant was in health and no mechanical or biological complications were noticed. The satisfactory results of this case encourage the realization of new studies to elucidate its reproducibility.

Fig. 1

Cone-beam computed tomography image. Residual ridge measurements before the 4.5-length “temporary” implant placement. Note the discrepancy between palatal and buccal areas.

Fig. 2

Cone-beam computed tomography image. Five months after the 4.5-length “temporary” implant placing. Three mm of bone gain over the implant apex could be observed.

Fig. 3

Panoramic image after the 5.5-length “definitive” implant placing.

Fig. 4

Composition: Prosthodontic rehabilitation detailed. The screw-retained crown was performed over a transepithelial (intermediate abutment). The suprastructure was designed and manufactured by CAD-CAM, covered with ceramic, and cemented to a Ti-interface.

Fig. 5

Composition: Panoramic image and clinical image 1 year after implant loading.

Fig. 6

Timeline of the treatment. MSFA, maxillary sinus floor augmentation.

Fig. 7

Maxillary sinus floor augmentation (MSFA) and 4.5 extra-short implant placing technique protocol.