Biological Principles and Physiology of Bone Regeneration under the Schneiderian Membrane after Sinus Lift Surgery: A Radiological Study in 14 Patients Treated with the Transcrestal Hydrodynamic Ultrasonic Cavitational Sinus Lift (Intralift)

Abstract

Introduction. Sinus lift procedures are a commonly accepted method of bone augmentation in the lateral maxilla with clinically good results. Nevertheless the role of the Schneiderian membrane in the bone-reformation process is discussed controversially. Aim of this study was to prove the key role of the sinus membrane in bone reformation in vivo. Material and Methods. 14 patients were treated with the minimal invasive tHUCSL-Intralift, and 2 ccm collagenous sponges were inserted subantrally and the calcification process followed up with CBCT scans 4 and 7 months after surgery. Results. An even and circular centripetal calcification under the sinus membrane and the antral floor was detected 4 months after surgery covering 30% of the entire augmentation width/height/depth at each wall. The calcification process was completed in the entire augmentation volume after 7 months. A loss of approximately 13% of absolute augmentation height was detected between the 4th and 7th month. Discussion. The results of this paper prove the key role of the sinus membrane as the main carrier of bone reformation after sinus lift procedures as multiple experimental studies suggested. Thus the importance of minimal invasive and rupture free sinuslift procedures is underlined and does not depend on the type of grafting material used.

Figure 1

Intralift: 6 mm gingival punch or 6 × 6 mm top crestal flap to approach the alveolar crest.

Figure 2

Intralift: trepanation of the subantral alveolar crest with the conical diamond coated tip TKW 1 for Piezotome.

Figure 3

Intralift: opening of the sinus floor with the round diamond coated tip TKW2 for Piezotome.

Figure 4

Intralift: preparation of the receptacle for the hydrodynamic cavitational ultrasound applicator with the diamond-coated tip TKW4 for Piezotome (preparation of a ventile seat).

Figure 5

Intralift: detachment of the sinus membrane with the detachment applicator TKW5 which is sealed towards the oral cavity by the receptacle. By hydrodynamic cavitational pressure the sinus membrane is elevated and a subantral volume of 2,5 ccm created.

Figure 6

Collagenous sponges used: (a) Resorba Dentalkegel/Resorba/GER (1,9 ccm), ((b), (c)) Implante Colageno/EURO-Klee/ES (2,0 ccm), (d) insertion demonstration on a training model (the sponge is inserted after the sinus-membrane was elevated with the Intralift method), (e) view from inside the sinus in a training model, (f) surgical site with sponge inserted.

Figure 7

CBCT scan measurements: yellow arrows: total distances height/width/depth, red reference cross: measurements of calcification thicknesses in 3, 6, 9, and 12 o'clock position.

Figure 8

Immediate presurgical (a) and postsurgical (b) OPG: the collagenous sponge shows similar to a mucocele or less.

Figure 9

Transversal and parasagittal CBCT scan 4 months subsequent to tHUCSL-Intralift. The even circular centripetal calcification process can be observed.

Figure 10

Transversal and parasagittal CBCT-scan 7 months post tHUCSL-Intralift. The ossification process is obviously completed.

Figure 11

OPG with final prosthetic treatment after 11 months.

Figure 12

Case 2: presurgical condition in panoramic X-ray.

Figure 13

Case 2: presurgical situation in transversal, paramedian sagittal and horizontal CBCT-scan.

Figure 14

Case 2: CBCT scan 4 months following tHUCSL-Intralift. The even circular centripetal calcification process can be observed.

Figure 15

Case 2: CBCT scan 7 months after tHUCSL-Intralift: the completion of the calcification process except some smaller patches of undermineralized areas can be observed.

Figure 16

Follow-up panoramic X-ray after completion of implant insertion and prosthetic treatment 12 months following tHUCSL-Intralift.

Figure 17

Case 3: presurgical (a) and immediate postsurgical (b) OPG: the collagenous sponge is almost not detectable. In this case the tHUCSL-Intralift was performed paracrestally from the buccal side due to the insufficient old bridge in site.

Figure 18

Case 3: transversal and parasagittal CBCT scan 4 months after tHUCSL-Intralift. The even circular centripetal calcification process can be observed.

Figure 19

Case 3: transversal and parasagittal CBCT scan 7 months following tHUCSL-Intralift. The ossification process is obviously completed. A slim denser line on the antral floor marks the transition to the original alveolar crest.

Figure 20

Case 3: panoramic X-ray after final prosthetic treatment after 11 months.