Volume change after maxillary sinus floor elevation with apatite carbonate and octacalcium phosphate.

PURPOSE: Maxillary molars have low alveolar bone height diameter due to the presence of the maxillary sinus; thus, a sinus lift may be required in some cases. Changes in the volume of bone substitutes can affect the success of implant therapy. Therefore, this study aimed to compare the changes in the volume of two different bone substitutes-one based on carbonate apatite and the other on octacalcium phosphate-used in maxillary sinus floor elevation. METHODS: Nineteen patients and 20 sites requiring maxillary sinus floor elevation were included in the study. Digital Imaging and Communications in Medicine data for each patient obtained preoperatively and immediately and 6 months postoperatively were used to measure the volume of the bone grafting material using a three-dimensional image analysis software. The immediate postoperative volume of octacalcium phosphate was 95.3775 mm3 per piece of grafting material used. It was multiplied by the number of pieces used and converted to mL to determine the immediate postoperative volume. RESULTS: The mean resorption values of carbonate apatite and octacalcium phosphate were 12.7 ± 3.6% and 17.3 ± 3.9%, respectively. A significant difference in the amount of resorption of the two bone replacement materials was observed (P = 0.04). CONCLUSIONS: The results of this study indicate that both bone substitute materials tend to resorb. The two bone grafting materials that are currently medically approved in Japan have not been in the market for a long time, and their long-term prognosis has not yet been reported. Further clinical data are warranted.

Validation of an implant stability measurement device using the percussion response: a clinical research study.

BACKGROUND: Several devices have been developed to measure implant-bone stability as an indicator of successful implant treatment; these include Osstell®, which measures the implant stability quotient (ISQ), and the more recent AnyCheck®, which relies on percussion for the implant stability test (IST). These devices make it possible to measure implant stability. However, no studies have compared the performance of AnyCheck® and Osstell® (i.e., IST and ISQ values) in clinical practice. Therefore, this study aimed to determine the correlation between primary and secondary implant stability using the Osstell® and AnyCheck® devices. METHODS: Ten patients (7 women; age [mean ± standard deviation]: 49.1 ± 13.3 years) with partially edentulous jaws who received a total of 15 implants were included. IST (AnyCheck®) and ISQ (Osstell®) values were measured immediately after implantation and at 1, 2, 3, 4, and 6 weeks post-implantation. Each measurement was performed three times, and the average value was used as the result. The correlation between measurements obtained using the two devices was determined using Spearman's rank correlation coefficient. RESULTS: The IST values ranged from 79.1 ± 2.87 to 82.4 ± 2.65. The ISQ values ranged from 76.0 ± 2.8 to 80.2 ± 2.35. Spearman's rank correlation coefficient was r = 0.64 immediately after implantation, r = 0.29 at 1 week, r = 0.68 at 2 weeks, r = 0.53 at 3 weeks, r = 0.68 at 4 weeks, and r = 0.56 at 6 weeks. A positive correlation was found in all cases, except at week 1 when the correlation was weak; the IST and ISQ values decreased the most during the first postoperative week and increased during the second week. The IST values were also slightly higher at all measurement points. CONCLUSION: The ability to assess implant stability without removing the abutment during healing is essential for determining the timing of loading without the risk of bone resorption. The results of this study suggest that AnyCheck® is useful for determining primary and secondary implant stability.

Comparison of digital and silicone impressions for single-tooth implants and two- and three-unit implants for a free-end edentulous saddle.

BACKGROUND: The use of intraoral scanners (IOS) has facilitated the use of digital workflows for the fabrication of implant-supported prostheses not only for single missing teeth, but also for multiple missing teeth. However, the clinical application of IOS and computer-aided design/manufacturing (CAD/CAM) in implant-supported prosthodontics remains unclear. This study aimed to compare the accuracy of digital and silicone impressions for single-tooth implants for bounded edentulous spaces and two-unit and three-unit implant-supported fixed dental prostheses for free-end edentulous spaces. METHODS: This study enrolled 30 patients (n = 10 for each of the three groups) with an average age of 61.9 years. Conventional silicone-based and digital IOS-based impressions were made for all patients, and the implant superstructures were fabricated. We measured the scan-body misfit and compared the accuracy of the impressions for single-unit, two-unit, and three-unit implant prostheses with a bounded edentulous space by superimposing the standard triangulated language (STL) data obtained from IOS over the STL data of the plaster model used for final prosthesis fabrication. The scan bodies of the superimposed single-molar implant, two-unit implant prosthesis without teeth on the mesial side, two-unit implant prosthesis without teeth on the distal side, three-unit implant prosthesis without teeth on the mesial side, and three-unit implant prosthesis without teeth on the distal side were designated as A, B1, B2, C1, and C2, respectively. The misfit for each scan body was calculated and the accuracies were compared using the Tukey-Kramer method. RESULTS: The average scan-body misfit for conditions A, B1, B2, C1, and C2 was 40.5 ± 18.9, 45.4 ± 13.4, 56.5 ± 9.6, 50.7 ± 14.9, and 80.3 ± 12.4 µm, respectively. Significant differences were observed between the accuracies of A and B2, A and C2, and C1 and C2 (P < 0.001). CONCLUSIONS: IOS and CAD/CAM can find clinical applications for implant-supported prostheses of up to three units for a bounded edentulous saddle. The use of IOS could render implant treatment easier, benefiting both the surgeons and patients. Prosthesis maladjustment may lead to peri-implantitis and prosthetic fracture. Therefore, further validation of the accuracy of IOS impressions is required in patients with multiple missing teeth in long-span implant prostheses.

Comparison of the performances of low-crystalline carbonate apatite and Bio-Oss in sinus augmentation using three-dimensional image analysis.

BACKGROUND: In locations where the alveolar bone height is low, such as at the maxillary molars, implant placement can be difficult, or even impossible, without procedures aimed at generating new bone, such as sinus lifts. Various types of bone graft materials are used after a sinus lift. In our study, a three-dimensional image analysis using a volume analyzer was performed to measure and compare the volume of demineralized bovine bone mineral (Bio-Oss®) and carbonate apatite (Cytrans®) after a sinus lift, as well as the amount of bone graft material resorption. Patient data were collected from cone-beam computed tomography images taken before, immediately following, and 6 months after the sinus lift. Using these images, both the volume and amount of resorption of each bone graft material were measured using a three-dimensional image analysis system. RESULTS: The amount of bone resorption in the Bio-Oss®-treated group was 25.2%, whereas that of the Cytrans®-treated group was 14.2%. A significant difference was found between the two groups (P < 0.001). CONCLUSIONS: Our findings indicate that the volume of bone resorption was smaller in the Cytrans®-treated group than in the Bio-Oss®-treated group, suggesting that Cytrans® is more promising for successful implant treatments requiring a sinus lift.