Assessment Of The Capability Of OSSTEM CAS-KIT System For Sinus Augmentation

Objective: Implant therapy has become a commonly used dental procedure to restore the edentulous jaw in daily clinic.However,lacking of vertical bone height of the residual ridge and enlarged sinus cavities are often a major obstacle to the placement of dental implants in the maxillary posterior area.In order to facilitate implant placement in the atrophic posterior maxilla,the sinus augmentation procedure has been used.There are two surgical approaches for sinus floor lifting including lateral window approach and crestal approach.Previous studies of sinus augmentation using lateral window technique(LWT)reported a number of intraoperative and postoperative complications,such as perforation of the sinus membrane,hemorrhage,fracture of the residual alveolar ridge,graft loss,infection,etc.Also,some papers have reported the complications appeared using crestal approach,which in most cases occurred during the use of rotary instruments for sinus wall osteotomy.Thus,various surgical procedures and devices have been developed to overcome the shortcomings of the osteotome technique and lateral window technique.Several surgical procedures have been proposed to minimize the sinus membrane perforation rate by using hydraulic pressure instead of tapping force,the so-called “hydraulic sinus lift” procedure.Recently,CAS-KIT(Crestal Approach-Sinus Kit,OSSEN Co.,South Korea)have developed a new device for the sinus lift procedure by the crestal approach using a special drilling system and hydraulic pressure.The purpose of this study was to evaluate the clinical outcomes of implants placed using CAS-Kits in maxillary sinus augmentation.Methods: Medical records of patients who have received implant placement using CAS kits in the posterior maxillary area at the department of Oral and Maxillofacial Surgery,Chonnam National University Dental Hospital from July 2014 to August 2016 were retrospectively examined.The study sample comprised 41 implants in 15 men(47%)and 17 women(53%),ranging in age from 19 to 78 years(median age 48.5years)performed by the same oral surgeon.Pre-operative panoramic radiograph and Cone-beam CT image were taken in each patient to assess the residual bone height and density,mucosa thickness,sinus septa,and the possible presence of pathology before and 7 days after the operation.The post-operative panoramic radiograph was taken at 1week,1 month,6 months and 1 year after implant placement with CAS kits.After a healing time of 6 months,second stage surgery was performed and implants were restored with prosthetic loading.The prosthetic reconstruction was made by the same surgeon and was completed and loaded about 1 month later.Result: A total of 41 hydraulic lift procedures using CAS-KIT technique were performed in 32 patients(15 men and 17 women).However,5 implants were excluded because of lacking of medical records.Thus,a total of 36 implants were inserted using CAS-KIT technique in 27 patients(12 men and 15 women)ranging in age from 19 to 78years(median age 48.5 years).The height of the maxillary residual bone height(RBH)in the intended implant sites was a mean of 5.08±1.54 mm(range 2.21 to 9.86 mm),and the elevation of the sinus floor was a mean of 2.29±0.96 mm(range 0.59 to 4.75 mm)after the surgery.No intraoperative and post-operative complications,including perforation of Schneiderian membrane,perioperative hemorrhages,postoperative hemorrhages,postoperative maxillary sinusitis,local wound dehiscences,graft infections,loss of graft and loss of implants,were observed in any of the patients.The 0to 1 year cumulative implant survival rate was 100%.Conclusion: In conclusion,within the limitation of the present study,it can be suggested that the CAS-KIT technique may have predictable results when used as a hydraulic maxillary sinus lifting system via the crestal approach.The results of this study demonstrated low complication rate and high survival rate.However,longer-term clinical studies are required to confirm our results.