Preliminary Study for Hydraulic Sinus Membrane Elevation by CAS KIT without Bone Graft
By: Kun-Soo Chang, Kyung-gyun Hwang, Chang-Joo Park
The purpose of this preliminary study is to investigate the feasibility of no bone graft in maxillary sinus elevation during the implant treatment and to evaluate the amount of bone formation under a sinus membrane tented with implants and filled with saline or venous blood as a graft material in edentulous area of maxillary posterior. Instead of lateral approach, CAS KIT (Osstem, Korea), which is famous for hydraulic sinus membrane elevation via crestal approach, is utilized in this study.
Materials & Methods:
In a patient with the posterior maxillary edentulism, the placement of dental implants, hydraulic sinus membrane elevation via crestal approach by CAS KIT, and saline or venous blood filling for space maintenance were performed (Fig 1).
Their residual alveolar bone height (RBH) was over 5 mm and the length of dental implants was selected as near doubled RBH. Periapical and panoramic radiographs, including cone-beam computed tomography (CT), which were taken preoperatively (T0), and at postoperative 1 months (T1), 6 months (T2), and 12 months (T3), were used to evaluate the bone formation in the maxillary sinus floor.
Fig. 1. Lift membrane using hydraulic lift system
The study population comprised 20 patients, 11 men and 9 women, ranging from 27 to 70 years in age (mean age, 45 years). Sinus lift procedures were performed by CAS KIT with implant placement simultaneously. Saline or venous blood filling for space maintenance were performed in each 10 cases. No significant complications were observed in any of the patients during the healing period, except for physiologic swelling after surgery. In a total 35 implants (TSIII CA, Osstem, Korea), 14 implants were inserted at premolar areas and 21 implants at molar areas. Of these implants, 3 were TSIII CA 4.0mm x 10mm,7 were TSIII 4.0 x 11.5mm, 1 was TSIII 4.5mm x 8.5mm, 3 were TSIII 4.5mm x 10mm, 16 were 4.5 x 11.5mm,1 was TSIII 5.0mm x 10mm, and 3 were 5.0mm x 10mm (Table 1).
Fig. 2. Staged CBCT image (coronal view) (a) preperative (T0) (b) immediate postoperative (c) postoperative 12months (T3)
There were no signs or symptoms of infection or maxillary sinus disease. Thirty-five implants in lengths of 8.5 to 11.5 mm were placed, with an average RBH of 6.8 mm (range 5-9 mm). All the implants remained clinically stable during the study period. Comparison of pre- and postoperative radiographs clearly demonstrated bone formation within the compartment created by the sinus elevation procedure, however, slight drooping of the sinus membrane was observed in all the cases.
Table 1. Basic data for this prospective clinical study
Table 2. Measurement of average residual alveolar bone height (RBH)
Fig 3. Schematic drawing showing the measurement of intra-sinus newly formed bone level in the maxillary sinus as measured in CBCT over time (*significant difference at P < 0.05)
Maxillary sinus membrane elevation with the simultaneous placement of implants without the use of any additional grafting material resulted in intra sinus hard tissue formation around the implants for a follow-up period of up to 12 months. According to our observations, filling of peripheral venous blood instead of a graft material can be a more viable alternative to bone substitutes and safely used in maxillary sinus augmentation than filling of saline. New bone formation was verified by the stabilization of the elevated sinus membrane from the tenting effect of placement of dental implants and clots of venous blood without bone graft material. Our preliminary study shows that successful bone formation in the sinus floor by hydraulic sinus membrane elevation using CAS KIT without bone graft.