This approach starts like BAOSFE. The osteotomy is enlarged to 5.0 mm before the balloon (Zimmer Sinus Lift Balloon, Zimmer Dental Inc., California, USA) is inserted (Fig. 3). The sinus floor was broken with the 5 mm osteotome after the addition of bone. The sleeve of the balloon was inserted 1 mm beyond the sinus floor. The saline was injected slowly from the syringe into the balloon, so the balloon would inflate progressively (Fig. 4). The balloon was deflated, and the desired elevation was checked if the elevation was not reached. The balloon was inserted again, and the process is repeated until the desired 7 mm are reached. One cubic centimeter of saline is expected to lift the membrane for 6 mm [13].

The CAS kit consists of a set of safe end drills, metal stoppers, a depth gauge, a hydraulic lifter, bone graft carrier, condenser, and a bone spreader (Fig. 5). The procedure started with a 2-mm twist drill. The drills were used to enlarge the osteotomy and are stopped 1 mm short of the sinus floor. The sinus floor was broken with the 3.6 mm bur without going through the floor; a depth gauge was used to check the membrane integrity and to slightly lift the membrane. Then, the hydraulic lifter was inserted and stabilized (Fig. 6) and the saline solution is injected. 0.30 mL can elevate the membrane up to 3 mm [5]. The saline is drown out then injected again until the desired elevation is reached.

Chi-square test was used to test the association between the three techniques and the occurrence of perforation whereas ANOVA (analysis of variance) was used to assess the association between method used and the two outcomes of the length of the perforation and the time of operation. Logistic regression of method used on the occurrence of perforation was employed to evaluate the odds of perforation for each method. P values equal to or smaller than .05 were considered to be significant. All calculations were made using SPSS version 16 for Windows (SPSS®, Chicago, IL, USA).