Long-term Clinical Evaluation Of Internal Maxillary Sinus Floor Elevation With Simultaneous Implantation By The Disk-up Sinus Reamer

Objective: The aim of the study was to analyze the results of long-term clinical and radiographic data of internal sinus floor elevation by the disk-up sinus reamer(DSR)with simultaneous implantation,in order to appraise long-term clinical effects of the DSR and provide clinical evidences of its popularization and application.Methods: A total of 192 patients,109 males and 83 females,were accepted from March 2008 to 2013 in the Oral Implant Center of the Affiliated Hospital of Qingdao University.The enrollment criterion was partial or full edentulism in the posterior maxilla with a residual bone height from 1 to 8 mm,6.03±1.84 mm in average,as measured using panoramic radiography or CBCT.All the patients were performed internal sinus floor elevation procedures with simultaneous implantation by the DSR,which was followed by immediate radiographic assessment to observe implant direction,sinus membrane integrity and elevation height.The estimated healing time for success of the implants was 3 to 9 months.During the 1 to 5 years follow-up,clinical examinations including implant mobility and health conditions of soft tissue surrounded were conducted and radiographic measurements of endo-sinus bone gain and marginal bone loss were carried out postoperatively.Data were statistically analyzed.Results:(1)8 of 192 membrane perforations occurred during sinus lifting and the perforation rate was 4.17%.All of these 8 patients suffered no sinus complications after changing into lateral sinus floor elevation with a bio-guide membrane.These 8 patients of 9 implants were excluded.(2)194 implants were installed in the remaining 184 patients simultaneously and 5 implants failed during the first 5-year follow-up and the cumulative survival rate was 97.4%(3)The PD,BI and GI was 3.23±0.51mm?1.29±0.71 and 1.28±0.67 respectively 5 years after operation,which were within the normal range.(4)The ESBG after surgery,6 months after surgery,1year after surgery and 5 years after surgery was 5.44 ± 1.75 mm,4.74 ± 1.77 mm,4.68 ± 1.80 mm and 4.62 ± 1.80 mm respectively.The ESBG after surgery was significantly different from that of 6 months after surgery,1 year after surgery and 5 years after surgery,while for the ESBG 6 months after surgery,1 year after surgery and 5 years after surgery,there was no significant difference between each group.(6)The MBL after restoration,1 year after surgery and 5 years after surgery was 0.33±0.68 mm,1.06±0.96 mm and 1.09±0.87 mm respectively.Significant differents were found between the MBL after restoration and 1 year after surgery and between after restoration and 5 years after surgery.There was no significant difference between the MBL 1 year after surgery and 5 years after surgery.Conclusion:(1)The DSR-based sinus floor elevation could effectively reduce the membrane perforation rate and install the implants simultaneously with RBH less than 5mm.(2)The DSR-based sinus floor elevation could achieve a predictable ESBH and get a satisfactory osseointegration.(3)The DSR-based sinus floor elevation with implantation combined in atrophic maxilla proves to be highly successful in the long-term clinical study and worthy of popularization and application.