Effect of Tricalcium Phosphate Foam and Paste Bone Grafting Materials Designed for Improved Surgical Handling on Osteogenesis in a Sheep Scapula Model

Reconstruction of critical-size bone defects (CSDs) with complex defect morphologies remains clinically challenging. The desire to avoid autograft harvesting has prompted an increasing quest for adequate synthetic bone grafting materials. The clinical success rates, which have been achieved with bioactive β-tricalcium phosphate granules (TCP-G) demonstrate that these materials have become an excellent alternative graft choice. In order to improve surgical handling properties, TCP-G have been combined with natural polymers for creating paste- and foam-like materials, which can easily be molded into any desired shape when grafting a given bony defect or deploying them with a syringe. This study assessed the effect of a TCP paste (TCP-P) and a TCP-foam (TCP-F) bone grafting material as compared to TCP-G on bone formation and osteogenic marker expression after 1, 3, 6, 12, and 18 months of implantation in CSD in the sheep scapula and tested the hypothesis that the addition of natural polymers would not diminish the osteogenic properties of TCP-P and TCP-F. The bone and bone graft material area fractions were determined histomorphometrically in order to quantify bone formation and bone graft material resorption. Immunohistochemical analysis of collagen type I, osteocalcin, and bone sialoprotein expression in the various cell and matrix components of the bone tissue was performed on resin-embedded sections for characterizing the osteogenic and bioactive properties of the test materials. By 6 months, all three TCP materials facilitated excellent defect regeneration with further bone remodeling at 12 and 18 months. TCP-F and TCP-P induced greater osteocalcin expression and exhibited more advanced graft material resorption at 1 and 6 months, respectively. At 18 months, all three grafting materials were almost fully resorbed with the original bony architecture being restored. Taken together, the hyaluronic acid and methylcellulose components in TCP-P and porcine collagen components in TCP-F did not diminish the osteogenic capacity of TCP-P and TCP-F, which exhibited an even slightly higher resorbability and enhancement effect on OC expression by osteoblasts.

Radiographic graft changes following maxillary sinus floor augmentation with autogenous bone compared with composite grafts: a one-year single-blind randomized controlled trial

This study evaluated radiographic graft changes following maxillary sinus floor augmentation with (A) autogenous bone, (B) 1:1 autogenous bone and deproteinized porcine bone mineral, or (C) 1:1 autogenous bone and biphasic bone graft material. Sixty patients were randomly allocated to groups A, B, and C (20 in each). CBCT scans were obtained at enrolment, after surgery (T1), after prosthetic rehabilitation (T2), and 1 year after implant loading (T3). Significant decreases in graft volume (3D) and graft height (2D) from T1 to T3 were observed in all groups (P < 0.05). However, at T2 and T3, graft volume was significantly higher in group B than in groups A and C (P < 0.05), and graft height was significantly higher in group B than in group A (P < 0.05). Bone density increased significantly from T1 to T2 in all groups (P < 0.001). However, bone density was significantly higher in group B than in groups A and C, at T2 and T3 (P < 0.05). No significant correlation between graft volume or height and implant protrusion length or residual bone height was found. In conclusion, 1:1 autogenous bone and porcine bone resulted in significantly higher graft volume, height, and bone density when compared with autogenous bone or a 1:1 ratio of autogenous bone and biphasic bone. However the higher graft volume, height, and bone density did not appear to lead to improved outcomes at 1 year of functional loading when compared to the other groups.

Endo-sinus bone gain following sinus membrane elevation without graft compared with sinus floor augmentation and a composite graft: a one-year single-blind randomized controlled trial

The objective of this study was to assess endo-sinus bone gain (ESBG) and bone density (BD) following maxillary sinus membrane elevation without graft (test) compared with maxillary sinus floor augmentation and 1:1 ratio of autogenous bone from the buccal antrostomy and deproteinized porcine bone mineral (control) using two- and three-dimensional radiographic methods. Forty healthy patients were randomly allocated to the test and control groups. Cone beam computed tomography scans were obtained at enrolment (T0), immediately after surgery (T1), at delivery of the prosthetic rehabilitation (T2), and 1 year after functional implant loading (T3). Mean differences were expressed with the 95% confidence interval. Significance was set at ≤ 0.05. ESBG and BD were significantly higher in the control group than test group at T1, T2, and T3 (P < 0.001). A significant decrease in ESBG and increase in BD was observed from T1 to T3 with both treatments (P < 0.001). There was a non-significant positive correlation of ESBG with implant protrusion length and non-significant negative correlation with residual bone height. In conclusion, test was associated with significantly lower ESBG and BD compared with control. However, the lower ESBG and BD did not appear to negatively affect the implant stability quotient or implant treatment outcome after 1 year of functional implant loading.

Quantitative analysis of change in bone volume 5 years after sinus floor elevation using plate-shaped bone substitutes: a prospective observational study

PURPOSE

Tricalcium phosphate (TCP) has osteoconductive ability and reportedly offers similar clinical results as autogenous bone grafts in dental implant treatment. However, few reports quantify temporal changes in augmented bone volume after sinus augmentation. We aimed to establish a three-dimensional (3D) quantification method to assess bone volume after sinus augmentation and to evaluate biocompatibility of the TCP plate.

METHODS

Maxillary sinus floor augmentation was performed employing the lateral window technique, and plate-shaped β-TCP (TCP plate) was used instead of granular bone grafting materials. After lifting the sinus membrane, the TCP plate was inserted and supported by dental implants or micro-screws. The changes in bone volumes in the maxillary sinus before and after surgery were recorded using cone-beam computed tomography, saved as Digital Imaging and Communications in Medicine-formatted files, and transformed to Standard Triangle Language (STL)-formatted files. Pre- and post-operative STL data of bone volume were superimposed, and the augmented bone volume was calculated. Moreover, changes in bone volumes, TCP plate resorption rates, and bone heights surrounding the implants were three dimensionally quantified.

RESULTS

Fifteen implants in nine subjects were included in this study. TCP plates secured long-term space making, with results similar to those of granular bone substitutes. Newly formed bone was identified around the implant without bone graft material. TCP plate was absorbed and gradually disappeared.

CONCLUSIONS

A novel 3D quantification method was established to evaluate changes in bone volume. Clinical application of TCP plate in sinus augmentation could be a better procedure in terms of prognosis and safety.

Osteogenic Effect of a Bioactive Calcium Alkali Phosphate Bone Substitute in Humans

(1) Background: The desire to avoid autograft harvesting in implant dentistry has prompted an ever-increasing quest for bioceramic bone substitutes, which stimulate osteogenesis while resorbing in a timely fashion. Consequently, a highly bioactive silicon containing calcium alkali orthophosphate (Si-CAP) material was created, which previously was shown to induce greater bone cell maturation and bone neo-formation than β-tricalcium phosphate (β-TCP) in vivo as well as in vitro. Our study tested the hypothesis that the enhanced effect on bone cell function in vitro and in sheep in vivo would lead to more copious bone neoformation in patients following sinus floor augmentation (SFA) employing Si-CAP when compared to β-TCP. (2) Methods: The effects of Si-CAP on osteogenesis and Si-CAP resorbability were evaluated in biopsies harvested from 38 patients six months after SFA in comparison to β-TCP employing undecalcified histology, histomorphometry, and immunohistochemical analysis of osteogenic marker expression. (3) Results: Si-CAP as well as β-TCP supported matrix mineralization and bone formation. Apically furthest away from the original bone tissue, Si-CAP induced significantly higher bone formation, bone-bonding (bone-bioceramic contact), and granule resorption than β-TCP. This was in conjunction with a higher expression of osteogenic markers. (4) Conclusions: Si-CAP induced higher and more advanced bone formation and resorbability than β-TCP, while β-TCP's remarkable osteoconductivity has been widely demonstrated. Hence, Si-CAP constitutes a well-suited bioactive graft choice for SFA in the clinical arena.

Clinical, radiographic, and histological/histomorphometric analysis of maxillary sinus grafting with deproteinized porcine or bovine bone mineral: A randomized clinical trial

OBJECTIVE

The present study aimed to compare histomorphometrically evaluated new bone formation, radiographically measured graft stability, and clinical implant outcome between maxillary sinus grafting with either deproteinized porcine bone mineral (DPBM) or deproteinized bovine bone mineral (DBBM).

MATERIALS AND METHODS

Thirty maxillary sinuses were initially included and randomly assigned to the test group (TG; DPBM, n = 15) or control group (CG; DBBM, n = 15). After a healing period (6 months), axially retrieved bone biopsies of the molar region were used for histological/histomorphometric analysis of new bone formations. Additionally, radiographically measured graft stability and clinical implant outcome were assessed.

RESULTS

Twenty-three sinus sites with 10 sinuses of the TG and 13 of the CG were ultimately available for data and statistical analysis. In the TG, a slightly, but yet significantly (p = .040) higher proportion of new bone formation (TG: 27.7 ± 5.6% vs. CG: 22.9 ± 5.1%) and a lesser (p = .019) amount of connective (non-mineralized) tissue (TG: 47.5 ± 9.5% vs. CG: 56.1 ± 9.5%) was found than in the CG. However, both xenografts showed comparable (n.s.) residual bone graft (TG: 23.7 ± 7.2% vs. CG: 21.1 ± 9.85.6%), bone-to-graft contacts (TG: 26.2 ± 9.8% vs. CG: 30.8 ± 13.8%), similar graft height reduction over time (TG: 12.9 ± 6.7% CG: 12.4 ± 5.8%) and implant survival/success rate (100%). At the 3-year post-loading evaluation, the peri-implant marginal bone loss (TG: 0.52 ± 0.19 mm; CG: 0.48 ± 0.15 mm) and the peri-implant health conditions (TG: 87.5%/CG: 81.2%) did not differ between implants inserted in both xenografts used.

CONCLUSIONS

The use of DPBM or DBBM for maxillary sinus augmentation is associated with comparable bone formation providing stable graft dimension combined with healthy peri-implant conditions.

A tissue engineered 3D printed calcium alkali phosphate bioceramic bone graft enables vascularization and regeneration of critical-size discontinuity bony defects in vivo

Introduction: Recently, efforts towards the development of patient-specific 3D printed scaffolds for bone tissue engineering from bioactive ceramics have continuously intensified. For reconstruction of segmental defects after subtotal mandibulectomy a suitable tissue engineered bioceramic bone graft needs to be endowed with homogenously distributed osteoblasts in order to mimic the advantageous features of vascularized autologous fibula grafts, which represent the standard of care, contain osteogenic cells and are transplanted with the respective blood vessel. Consequently, inducing vascularization early on is pivotal for bone tissue engineering. The current study explored an advanced bone tissue engineering approach combining an advanced 3D printing technique for bioactive resorbable ceramic scaffolds with a perfusion cell culture technique for pre-colonization with mesenchymal stem cells, and with an intrinsic angiogenesis technique for regenerating critical size, segmental discontinuity defects in vivo applying a rat model. To this end, the effect of differing Si-CAOP (silica containing calcium alkali orthophosphate) scaffold microarchitecture arising from 3D powder bed printing (RP) or the Schwarzwalder Somers (SSM) replica fabrication technique on vascularization and bone regeneration was analyzed in vivo. In 80 rats 6-mm segmental discontinuity defects were created in the left femur. Methods: Embryonic mesenchymal stem cells were cultured on RP and SSM scaffolds for 7d under perfusion to create Si-CAOP grafts with terminally differentiated osteoblasts and mineralizing bone matrix. These scaffolds were implanted into the segmental defects in combination with an arteriovenous bundle (AVB). Native scaffolds without cells or AVB served as controls. After 3 and 6 months, femurs were processed for angio-µCT or hard tissue histology, histomorphometric and immunohistochemical analysis of angiogenic and osteogenic marker expression. Results: At 3 and 6 months, defects reconstructed with RP scaffolds, cells and AVB displayed a statistically significant higher bone area fraction, blood vessel volume%, blood vessel surface/volume, blood vessel thickness, density and linear density than defects treated with the other scaffold configurations. Discussion: Taken together, this study demonstrated that the AVB technique is well suited for inducing adequate vascularization of the tissue engineered scaffold graft in segmental defects after 3 and 6 months, and that our tissue engineering approach employing 3D powder bed printed scaffolds facilitated segmental defect repair.

Comparison of Particulate, Block and Putty Forms of β-tricalcium Phosphate-Based Synthetic Bone Grafts on Rat Calvarium Model

Purpose

Bone augmentation is a necessity for atrophied alveolar ridge prior to dental implant placement. Various bone graft types and forms with different characteristics are available in the market for alveolar augmentation. Beta tricalcium phosphate (β-TCP) is a synthetic biomaterial known as the oldest type of calcium phosphate. Studies comparing particulate, block or putty grafts are very limited. The aim of this study was to compare the particulate, block and putty forms of the same β-TCP bone graft and analyze the efficiency in critical size calvarium defects.

Material and Methods

Twenty male Wistar-Albino rats were employed for the study. Four bicortical bone defects with 5 mm diameter were created on each rat calvarium, and three defects were filled with particulate, block or putty β-TCP graft and one defect was left empty. The animals were killed after 8 weeks. New bone formation, residual graft, loose connective tissue, condensed mesenchyme, alkaline phosphatase, proliferating cell nuclear antigen, osteocalcin were measured on the specimens.

Results

Compared to block and putty forms, significantly higher new bone formation and least residual graft were observed in the particulate graft group. The residual graft was significantly higher in the block graft group than both the particulate and the putty groups. The cellular immunoreactivity of the samples in the particulate graft group was significantly higher. There was no significant difference between putty and block graft groups.

Conclusion

Bone regeneration is significantly affected by the form of β-TCP bone graft, and the particulate form was the most successful in our study.

CBCT for Diagnostics, Treatment Planning and Monitoring of Sinus Floor Elevation Procedures

Sinus floor elevation (SFE) is a standard surgical technique used to compensate for alveolar bone resorption in the posterior maxilla. Such a surgical procedure requires radiographic imaging pre- and postoperatively for diagnosis, treatment planning, and outcome assessment. Cone beam computed tomography (CBCT) has become a well-established imaging modality in the dentomaxillofacial region. The following narrative review is aimed to provide clinicians with an overview of the role of three-dimensional (3D) CBCT imaging for diagnostics, treatment planning, and postoperative monitoring of SFE procedures. CBCT imaging prior to SFE provides surgeons with a more detailed view of the surgical site, allows for the detection of potential pathologies three-dimensionally, and helps to virtually plan the procedure more precisely while reducing patient morbidity. In addition, it serves as a useful follow-up tool for assessing sinus and bone graft changes. Meanwhile, using CBCT imaging has to be standardized and justified based on the recognized diagnostic imaging guidelines, taking into account both the technical and clinical considerations. Future studies are recommended to incorporate artificial intelligence-based solutions for automating and standardizing the diagnostic and decision-making process in the context of SFE procedures to further improve the standards of patient care.

Long-Term Results after Placing Dental Implants in Patients with Papillon-Lefèvre Syndrome: Results 2.5-20 Years after Implant Insertion

Aim: A retrospective evaluation of patients with Papillon-Lefèvre syndrome (PLS) treated with dental implants to identify factors that may influence treatment outcomes. Methods: All PLS patients with dental implants currently registered at the Department of Periodontology, Goethe-University Frankfurt (20–38 years; mean: 29.6 years), were recruited. Five patients from three families (two pairs of siblings) with a total of 48 dental implants (inserted in different dental institutions) were included with a follow-up time of 2.5–20 years (mean: 10.4 years). Results: Implant failure occurred in three patients (at least 15 implants). Nearly all patients demonstrated peri-implantitis in more or less advanced stages; 60% of patients demonstrated bone loss ≥50% around the implants. Two patients did not follow any supportive therapy. Conclusions: Implants in PLS patients who did not follow any maintenance programme had a high risk of peri-implantitis and implant loss.

Radiographic Analysis of Graft Dimensional Changes after Lateral Maxillary Sinus Augmentation with Heterologous Materials and Simultaneous Implant Placement: A Retrospective Study in 18 Patients

Background: This investigation aimed to radiographically assess the variations of graft dimension following maxillary sinus augmentation by the lateral approach. Methods: Eighteen patients (seven males), with a mean age at surgery of 66.5 ± 9.8 (range 52−82) years, were unilaterally treated. Thirty-five dental implants were positioned in the posterior maxilla simultaneously to grafting with heterologous biomaterials. Intraoral radiographs taken at the time of surgery, after six months, and at the longest follow-up (up to nine years after implant placement) were analyzed. The following distances were measured: mesio-distal width of the graft, vertical distance from implant apex to most coronal level of the graft, distance from the mesial aspect of the (mesial) implant to the mesial graft extension; distance from the distal aspect of the (distal) implant to the distal graft extension, and graft height along the implant axis. The dimensional changes with respect to baseline, after six months and at the longest follow-up were calculated. Results: The patient-based mean follow-up was 38.3 ± 30.1 months (range 12−108 months). The mean residual bone height at the mesial and distal aspect of the implants was 3.19 ± 2.05 mm and 2.65 ± 1.60 mm, respectively (p = 0.38). The mean graft width at baseline was 27.95 ± 5.23 mm, and the mean graft width reduction was 10.2 ± 12.7% (2.98 ± 3.62 mm) and 11.3 ± 14.4% (3.36 ± 4.08 mm) at six months and at the latest follow-up. The change was significant at six months (p = 0.005), but did not show significant further variation (p = 0.11). On the mesial and distal aspect, the mean graft extension decreased by 1.56 ± 2.67 mm and 0.84 ± 2.71 mm at the latest follow-up. No significant difference between mesial and distal changes was found (p = 0.24), suggesting that the biomaterial is resorbed homogeneously on both sides. The mean graft height was 11.92 ± 2.53 mm at baseline and decreased by 9.3 ± 9.05% (1.11 ± 1.09 mm) at six months (p < 0.001). Non-significant further changes were found at the latest follow-up (p = 0.10). Conclusions: after early remodeling, heterologous bone substitutes showed a good dimensional stability in the mid-term for maxillary sinus augmentation.

Radiographic Analysis of Graft Dimensional Changes in Transcrestal Maxillary Sinus Augmentation: A Retrospective Study

Background. The maxillary sinus lift is a popular and predictable technique associated with implant-supported rehabilitation of the severely atrophic maxilla. The aim of the present retrospective study was to investigate the effectiveness of transcrestal maxillary sinus augmentation and the graft resorption pattern using different heterologous bone substitutes. Methods. A total of 75 sinus-grafting procedures were performed and 89 implants were placed in 66 patients, 24 males and 42 females, with mean age 67.9 ± 10.64 years (range 43−84 years). Nineteen subjects were smokers. The mean follow-up period was 93.33 ± 54.71 months (range 14−240 months). Clinical and radiographical evaluations were performed. Graft height and width were measured at baseline and at the latest follow-up. Results. Mesiodistal and vertical resorption averaged 9.3 ± 20.7% (standard deviation), and 5.04 ± 9.9% of the postoperative size, respectively, considering the graft as the unit. Linear regression analysis showed that graft resorption in both the vertical and the mesiodistal dimension is independent of the follow-up time. Conversely, there was a trend for greater resorption when increasing the postoperative graft size, in both vertical (p = 0.001) and horizontal (p = 0.007) dimensions. When grouping the dimensional changes by graft particle size (only small (<300 μm) particles, combination of small and medium (>500 μm)/large (>1000 μm) particles, and only medium/large particles), there was a trend for greater resorption associated with smaller particles, but it was not significant; neither in the mesiodistal nor in the vertical dimension (p = 0.17 and p = 0.25, respectively). No implant was lost during the observation period. In conclusion, the transcrestal technique for maxillary sinus augmentation documented a high level of predictability. The low clinical morbidity and the contextual dental implant positioning is clinically useful in relation to a significant reduction of the time required for implant restoration, a consistent decrease of the number of surgical phases, and a cost-effectiveness approach for the rehabilitation. The graft resorption pattern in all cases was compatible with persistent implant protection and support.

The Application of Beta-Tricalcium Phosphate in Implant Dentistry: A Systematic Evaluation of Clinical Studies

The demand for synthetic graft materials in implant dentistry is rising. This systematic review aims to evaluate the survival rate of dental implants placed simultaneously with bone regeneration procedures using the material β-tricalcium phosphate, one of the most promising synthetic graft materials. The electronic search was conducted in PubMed, Scielo, and the Cochrane Central Register of Controlled Trials. Five randomized clinical trials, one non-randomized controlled clinical trial and four observational studies without control group were include. Implant survival rate and other clinical, radiographic, and histological parameters did not differ from those of implants placed simultaneously with another type of graft material, or placed in blood clots or natural alveolar ridges. Based on the available literature, β-tricalcium phosphate seems to be a promising graft material in implant dentistry. Nevertheless, more randomized clinical trials, with long follow-up periods, preoperative and postoperative CBCT, and histological analysis, are necessary to assess its long-term behavior.

Clinical Outcome and 8-Year Follow-Up of Alveolar Bone Tissue Engineering for Severely Atrophic Alveolar Bone Using Autologous Bone Marrow Stromal Cells with Platelet-Rich Plasma and β-Tricalcium Phosphate Granules

Background: Although bone tissue engineering for dentistry has been studied for many years, the clinical outcome for severe cases has not been established. Furthermore, there are limited numbers of studies that include long-term follow-up. In this study, the safety and efficacy of bone tissue engineering for patients with a severely atrophic alveolar bone were examined using autogenous bone marrow stromal cells (BMSCs), and the long-term stability was also evaluated. Methods: BMSCs from iliac bone marrow aspirate were cultured and expanded. Then, induced osteogenic cells were transplanted with autogenous platelet-rich plasma (PRP) and β-tricalcium phosphate granules (β-TCP) for maxillary sinus floor and alveolar ridge augmentation. Eight patients (two males and six females) with an average age of 54.2 years underwent cell transplantation. Safety was assessed by monitoring adverse events. Radiographic evaluation and bone biopsies were performed to evaluate the regenerated bone. Results: The major population of transplanted BMSCs belonged to the fraction of CD34⁻, CD45^dim, and CD73⁺ cells, which was only 0.065% of the total bone marrow cells. Significant deviations were observed in cell growth and alkaline phosphatase activities among individuals. However, bone regeneration was observed in all patients and the average bone area in the biopsy samples was 41.9% 6 months following transplantation, although there were also significant deviations among each case. No adverse events related to the transplants were observed. In the regenerated bone, 27 out of 29 dental implants were integrated. Dental implants and regenerated bone were stable for an average follow-up period of 7 years and 10 months. Conclusions: Although individual variations were observed, the results showed that bone tissue engineering using BMSCs with PRP and β-TCP was feasible for patients with severe atrophic maxilla throughout a long-term follow-up period and was considered safe. However, further studies with a larger number of cases and controls to confirm the efficacy of BMSCs and the development of a protocol to establish a reproducible quality of stem cell-based graft material will be required.

Radiographic and Histomorphometric Evaluation of Biomaterials Used for Lateral Sinus Augmentation: A Systematic Review on the Effect of Residual Bone Height and Vertical Graft Size on New Bone Formation and Graft Shrinkage

The aim of the present systematic review was to investigate the effect of residual bone height (RBH) and vertical bone gain on new bone formation (NBF) and graft shrinkage after lateral sinus lifts using different biomaterials.

METHODS

An electronic search was conducted on three databases to identify randomized controlled trials (RCTs) published until January 2021 with at least one follow-up at 6 months and at least five patients treated, comparing biomaterials used for maxillary sinus augmentation with a lateral approach. Graft volumetric changes, RBH, vertical bone gain, implant failure, and post-operative complications were evaluated. The risk of bias was assessed using the Cochrane tool.

RESULTS

We used 4010 identified studies, of which 21 were RCTs. Overall, 412 patients and 533 sinuses were evaluated. Only three publications had an overall low risk of bias. After 6 months, xenograft (XG) showed the least volume reduction (7.30 ± 15.49%), while autogenous graft (AU) was the most reabsorbed (41.71 ± 12.63%). NBF appeared to not be directly correlated with RBH; on the contrary, the overall linear regression analysis showed that NBF significantly decreased by 1.6% for each mm of postoperative vertical graft gain. This finding suggests that the greater the augmentation, the lower the NBF. A similar tendency, with a regression coefficient even higher than the overall one, was also observed with alloplast (AP) and XG.

CONCLUSIONS

The present results suggested that NBF was essentially independent of preoperative bone height. On the contrary, the smaller the volume was of the graft placed, the higher the amount of new bone formed, and the smaller the graft shrinkage was. Minimizing the augmentation volume might be beneficial to graft healing and stability especially when using AP and XG.

Long-Term Clinical Study of Implants Placed in Maxillary Sinus Floor Augmentation Using Beta-Tricalcium Phosphate

Introduction. The aim of this study was to show the long-term clinical outcomes of implants placed in maxillary sinus floor augmentation (MFSA) using beta-tricalcium phosphate (β-TCP). Patients and methods. Maxillary patients were diagnosed for MFSA and used beta- β-TCP. After the lateral sinus surgery, implants were loaded at 6 months with restorations. The clinical follow-up was at 10 years. Results. One hundred and one patients (58 females and 43 males) were treated with MFSA. Twenty-nine patients (28.7%) had a history of periodontitis. Thirty-three patients (32.7%) were smokers. One hundred and twenty-one MFSA, 81 unilateral and 20 bilateral sites, with 234 implants were performed. The average vertical bone height available was 4.92 ± 1.83 mm. The average vertical bone gain obtained was 6.95 ± 2.19 mm following MFSA. The implant cumulative survival rate was 97.2%. Three implants (1.3%) were lost during the healing period. Six implants (2.6%) were lost by peri-implantitis. One hundred and fifteen restorations were placed in the patients. Mean marginal bone loss was 1.93 mm ± 1.03 mm. Six patients (27.3%) showed technical complications. Thirty-six implants (15.3%) in 14 patients (13.9%) were associated with peri-implantitis. Conclusions. This study indicates that treatment with implant-supported restoration by MFSA using β-TCP constitutes a successful implant approach.

Tissue Level Changes after Maxillary Sinus Floor Elevation with Three Types of Calcium Phosphate Ceramics: A Radiological Study with a 5-Year Follow-Up

This study evaluates the radiological changes in tissue height after maxillary sinus floor elevation (MSFE) using three types of calcium phosphate ceramics over a period of up to 5 years after dental implant placement. In 163 patients, MSFE was performed. Three groups of patients were distinguished and treated based on the type of calcium phosphate ceramic used and radiologically evaluated: 40 patients with β-tricalcium phosphate (β-TCP), 76 patients with biphasic calcium phosphate (BCP) 20% hydroxyapatite (HA)-80% β-TCP, and 47 patients with BCP 60% HA-40% β-TCP. Radiological measurements were performed on panoramic radiographs at several time points up to 5 years after dental implant placement. After MSFE, a slow decrease in tissue height measured over time was seen in all three study groups. Resorption of the grafted bone substitutes was more prominent in β-TCP than in BCP ceramics with an HA component (60/40 and 20/80). Loss of tissue height after 5 years was lowest in BCP 60/40 and highest in β-TCP. This radiological study shows a predictable and comparable behavior of the slow decrease in tissue height over time for all three types of calcium phosphate ceramics used in MSFE. The fraction of HA in calcium phosphate ceramics and dental implant loading seems to be beneficial for tissue height maintenance after MSFE.

Clinical and histological outcomes of maxillary sinus floor augmentation with synthetic bone substitutes for dental implant treatment: A meta-analysis

The objective of the present review was to gather all available human randomized clinical trials comparing the clinical and histological results of synthetic bone substitutes used in maxillary sinus floor augmentation. Authors electronically searched in Pubmed/Medline, Scopus and Cochrane databases to analyse the success of endosseous dental implant, implant failure, peri-implant marginal bone loss, newly formed bone and residual bone graft material.  After the search, ten randomized clinical trials were included. Four studies ranging from low to unclear risk of bias were used for meta-analysis, being able to compare only biphasic calcium phosphate (BCP) and deproteinized bovine bone (DBB). A greater amount of residual graft material (mean difference -MD- 4.80 mm; 95% CI, 9.35 to 0.26; P= 0.040) was found in DBB group. No other statistically significant differences were found between BCP and DBB for the rest of outcomes. Thus, our results suggested that BCP can be considered a suitable alternative to DBB in maxillary sinus floor augmentation due to its clinical and histological results.

Evaluation of maxillary sinus floor augmentation with the crestal approach and beta-tricalcium phosphate: a cone-beam computed tomography 3- to 9-year follow-up

Background

We performed maxillary sinus floor augmentation using the crestal approach and beta-tricalcium phosphate (β-TCP) and a long-term evaluation using cone-beam computed tomography (CBCT).

Methods

Twenty-three patients (30 implants) underwent sinus floor augmentation using the osteotome technique. Subjects underwent CBCT imaging before surgery, immediately after surgery, and at follow-up (≥ 3 years after surgery). We measured the changes in height of the augmented sinus floor (SL), the augmented bone above apex of the implant (BH), and the implant length that projected into the sinus (IL).

Results

The mean SL decreased from 6.54 ± 1.51 (immediately after surgery) to 3.11 ± 1.35 mm (follow-up). The mean BH decreased from 3.17 ± 0.97 to − 0.25 ± 1.19 mm; the maxillary sinus floor in many implants was near the apex at follow-up. The SL at follow-up showed a strong correlation with the IL (p = 0.0057).

Conclusions

Osteotome sinus floor elevation with beta-tricalcium phosphate was clinically effective. Cone-beam computed tomography analysis revealed that ≥ 3 years after surgery, the maxillary sinus floor was near the apex of the implant.

Efficacy of stem cell allograft in maxillary sinus bone regeneration: a randomized controlled clinical and blinded histomorphometric study

Purpose

This study aimed to evaluate the quality and quantity of newly generated bone in the maxillary sinus grafted with stem cell-based allograft material.

Methods

This study was a single site, prospective, blinded, randomized, and controlled clinical trial. Eleven subjects with 18 edentulous posterior maxillary sites requiring sinus augmentation for delayed implant placement using a lateral window approach were enrolled. At the time of sinus augmentation, test sinus was grafted with stem cell-based allograft (Osteocel Plus; NuVasive Therapeutics), while the control sinus was grafted with conventional cortico-cancellous allograft (alloOss; ACE Surgical). Cone beam computer tomography (CBCT) scan was taken before and 14 weeks post-sinus augmentation procedure, i.e., 2 weeks before implant placement. Thirty-six trephined core bone biopsies were harvested from the anterior and posterior grafted lateral-window osteotomy sites at the time of implant placement.

Results

The results showed a statistically significant difference in the vital bone percentage between the test and the control groups at the posterior grafted sites (p = 0.03). There was no significant difference in the percentage of vital bone between the anterior and posterior grafted sites within the test and control groups (p > .05). The CBCT analysis showed that the maxillary sinuses at the posterior grafted sites were statistically wider than those at the anterior grafted sites in both groups (p < .05).

Conclusions

Different allograft bone materials can be used in the maxillary sinus augmentation procedures. Stem cell allograft has more osteogenic potential with a better outcome in the wide posterior sinus.

Grafted bone remodeling following transcrestal sinus floor elevation: A cone-beam computed tomography study

Background

Transcrestal sinus floor elevation is a reliable procedure when additional bone height is needed for maxillary implant placement. However, the grafted bone undergoes remodeling and the dimensional stability of grafted bone height may be affected by several clinical factors, including graft material, sinus anatomy and the morphology of grafted space.

Methods

This retrospective study examined patients who had undergone transcrestal sinus floor elevation with synthetic biphasic calcium phosphate and single implant placement. The reduction of sinus graft height (GHR) after 6–8 months healing period was measured with cone-beam computed tomography (CBCT) images. Correlating factors, including vertical amount of implant protrusion (IP), sinus width, and the morphology of grafted space were analyzed by Spearman's correlation test.

Results

A total of 25 implant sites were analyzed. The mean GHR was 0.57 ± 0.49 mm, which was positively correlated with IP, vertical elevation height (VEH), and the ratio of vertical to horizontal elevation of the grafted space. However, GHR was not correlated with sinus width and mesial-distal or buccal-palatal width of the grafted space.

Conclusions

Synthetic biphasic calcium phosphate used in transcrestal sinus floor elevation underwent shrinkages and graft remodeling. Grafted height reduction was associated with IP, VEH, and the ratio of vertical to horizontal elevation of the grafted space.

Histologic, Histomorphometric, and Clinical Analysis of the Effects of Growth Factors in a Fibrin Network Used in Maxillary Sinus Augmentation

This randomized controlled clinical trial evaluated the effect of mineralized plasmatic matrix (MPM), comprised of synthetic graft and platelet concentrates, on new bone formation and volume stability over time in maxillary sinus lifting (MSL). Unilateral MSL was performed in 20 patients with either beta-tricalcium phosphate (β-TCP) or MPM grafts (10 sinuses each). Six months postsurgery, specimens were obtained with a trephine bur prior to implant placement in 39 cases. Volumetric changes in sinus augmentation were analyzed between 1 week (T-I) and 6 months (T-II) postsurgery. Histomorphometric and histological analyses of biopsy samples revealed mean new bone percentages of 35.40% ± 9.09% and 26.92% ± 7.26% and residual graft particle areas of 23.13% ± 6.16% and 32.25% ± 8.48% in the MPM and β-TCP groups, respectively (p < 0.05). The mean soft-tissue areas in the MPM and β-TCP groups were 41.48% ± 8.41% and 40.83% ± 8.86%, respectively (p > 0.05). Graft reductions between baseline and 6-months postprocedure in the β-TCP and MPM groups were 17.12% ± 13.55% and 14.41% ± 12.87%, respectively, with significant graft volume reduction observed in both groups (p < 0.05) while there is no significant difference between MPM and β-TCP groups (p > 0.05). Thus, MPM, representing growth factors in a fibrin network, increases new bone formation and has acceptable volume stability in MSL procedures

Sinus bone graft and simultaneous vertical ridge augmentation: case series study

Background

This study aims to examine the outcome of simultaneous maxillary sinus lifting, bone grafting, and vertical ridge augmentation through retrospective studies.

Methods

From 2005 to 2010, patients with exhibited severe alveolar bone loss received simultaneous sinus lifting, bone grafting, and vertical ridge augmentations were selected. Fifteen patients who visited in Seoul National University Bundang Hospital were analyzed according to clinical records and radiography. Postoperative complications; success and survival rate of implants; complications of prosthesis; implant stability quotient (ISQ); vertical resorption of grafted bone after 1, 2, and 3 years after surgery; and final observation and marginal bone loss were evaluated.

Results

The average age of the patients was 54.2 years. Among the 33 implants, six failed to survive and succeed, resulting in an 81.8% survival rate and an 81.8% success rate. Postoperative complications were characterized by eight cases of ecchymosis, four cases of exposure of the titanium mesh or membrane, three cases of peri-implantitis, three cases of hematoma, two cases of sinusitis, two cases of fixture fracture, one case of bleeding, one case of numbness, one case of trismus, and one case of fixture loss. Prosthetic complications involved two instances of screw loosening, one case of abutment fracture, and one case of food impaction. Resorption of grafted bone material was 0.23 mm after 1 year, 0.47 mm after 2 years, 0.41 mm after 3 years, and 0.37 mm at the final observation. Loss of marginal bone was 0.12 mm after 1 year, and 0.20 mm at final observation.

Conclusions

When sinus lifting, bone grafting, and vertical ridge augmentation were performed simultaneously, postoperative complications increased, and survival rates were lower. For positive long-term prognosis, it is recommended that a sufficient recovery period be needed before implant placement to ensure good bone formation, and implant placement be delayed.

Maxillary sinus augmentation using biphasic calcium phosphate: dimensional stability results after 3-6 years

Purpose

This study was designed to observe the resorption pattern of biphasic calcium phosphate (BCP) used for maxillary sinus augmentation over a 3- to 6-year healing period, and to investigate factors affecting the resorption of BCP.

Methods

A total of 47 implants placed in 27 sinuses of 22 patients were investigated. All patients had residual bone height less than 5 mm at baseline. The modified Caldwell-Luc approach was used to elevate the maxillary sinus membrane, and the sinus cavity was filled with BCP (70% hydroxyapatite and 30% β-tricalcium phosphate). Implant placement was done simultaneously or in a staged manner. Serial radiographic analysis was performed up to 6 years postoperatively.

Results

During the follow-up period, no implant loss was reported. The mean reduced height of the augmented sinus (RHO) was 0.27±1.08 mm at 36 months, and 0.89±1.39 mm at 72 months postoperatively. Large amounts of graft material (P=0.021) and a long healing period (P=0.035) significantly influenced the amount of RHO. In particular, there was a significant relationship between a healing period longer than 40 months and RHO.

Conclusions

BCP can achieve proper dimensional stability with minimal reduction of the graft height in a 3- to 6-year healing period after maxillary sinus augmentation. The healing period and the amount of graft material influenced the resorption of BCP.

Influence of the position of the antrostomy in sinus floor elevation assessed with cone-beam computed tomography: A randomized clinical trial

AIM

The aim of the present study was to evaluate dimensional variations of augmented sinus volumes after sinus floor elevation using a lateral approach placing the antrostomy close to the sinus floor or more cranially to it.

METHODS

Twenty-four healthy volunteers in need of sinus floor elevation were included in the study. The lateral approach was adopted placing the antrostomy randomly either close to the level of the sinus floor (group A) or approximately 3-4 mm cranially (group B). Cone-beam computed tomography (CBCT) was done before surgery (T0) and after 1 week (T1) and 9 months (T2), and analyses on dimensional variations were performed.

RESULTS

CBCT of 10 patients per group were analyzed. At T1, the sinus floor was found to be elevated by 9.8 ± 2.1 mm in group A and 10.9 ± 1.9 mm in group B. At T2, shrinkage of 2.0 ± 1.7 mm in group A and 1.4 ± 2.5 mm in group B was observed. The area was reduced approximately 18-24% between T1 and T2. The sinus mucosa width increased by 4.3-5 mm between T0 and T1, and regained the original dimensions at T2.

CONCLUSIONS

The more cranial the antrostomy, the greater the augmentation height after 9 months.

Comparative Histological and Histomorphometric Results of Six Biomaterials Used in Two-Stage Maxillary Sinus Augmentation Model after 6-Month Healing

Objectives

To evaluate the performances of six different bone substitute materials used as graft in maxillary sinus augmentation by means of histological and histomorphometric analysis of bone biopsies retrieved from human subjects after a 6-month healing period.

Materials and Methods

Six consecutive patients (3 males, 3 females, aged 50-72 years), healthy, nonsmokers, and with good oral hygiene, presenting edentulous posterior maxilla with a residual bone crest measuring ≤ 4 mm in vertical height and 3 to 5 mm in horizontal thickness at radiographic examination, were selected to receive sinus augmentation and delayed implant placement. Under randomized conditions, sinus augmentation procedures were carried out using mineralized solvent-dehydrated bone allograft (MCBA), freeze-dried mineralized bone allograft (FDBA), anorganic bovine bone (ABB), equine-derived bone (EB), synthetic micro-macroporous biphasic calcium-phosphate block consisting of 70% beta-tricalcium phosphate and 30% hydroxyapatite (HA-β-TCP 30/70), or bioapatite-collagen (BC). After 6 months, bone core biopsies were retrieved and 13 implants were placed. Bone samples were processed for histological and histomorphometric analysis. CT scans were taken before and after surgery. After 4 months of healing, patients were restored with a provisional fixed acrylic resin prosthesis, as well as after further 2-4 months with a definitive cemented zirconia or porcelain-fused-to-metal crowns.

Results

There were no postoperative complications or implant failures. The histological examination showed that all biomaterials were in close contact with newly formed bone, surrounding the graft granules with a bridge-like network. No signs of acute inflammation were observed. The histomorphometry revealed 20.1% newly formed bone for MCBA, 32.1% for FDBA, 16.1% for ABB, 22.8% for EB, 20.3% for HA-β-TCP 30/70, and 21.4% for BC.

Conclusions

Within the limitations of the present investigation, all the six tested biomaterials showed good biocompatibility and osteoconductive properties when used in sinus augmentation procedures, although the FDBA seemed to have a better histomorphometric result in terms of newly formed bone and residual graft material. This trial is registered with ClinicalTrials.gov Identifier (Registration Number): NCT03496688.

Maxillary Sinus Floor Augmentation With Synthetic Bone Substitutes Compared With Other Grafting Materials: A Systematic Review and Meta-analysis

OBJECTIVE

To test the hypotheses of no differences in implant treatment outcome after maxillary sinus floor augmentation (MSFA) with synthetic bone substitutes (SBS) compared with other grafting materials applying the lateral window technique.

MATERIALS AND METHODS

A MEDLINE/PubMed, Embase and Cochrane Library search in combination with hand-search of selected journals was conducted.

RESULTS

Five randomized controlled trials with low risk of bias fulfilled the inclusion criteria. SBS disclosed high survival rate of suprastructures and implants with no significant differences compared to autogenous bone graft or xenograft. Meta-analysis revealed a patient-based implant survival rate of 0.98 (confidence interval: 0.89-1.08), indicating no differences between SBS and xenograft. SBS demonstrated significant less newly formed bone compared with autogenous bone graft, whereas no significant difference was revealed as compared to xenograft. High implant stability values, limited periimplant marginal bone loss, and few complications were reported with SBS.

CONCLUSIONS

There seem to be no differences in implant treatment outcome after MSFA with SBS compared to other grafting materials.

Sinus Floor Augmentation Comparing an In Situ Hardening Biphasic Calcium Phosphate (Hydroxyapatite/β-Tricalcium Phosphate) Bone Graft Substitute with a Particulate Biphasic Calcium Phosphate (Hydroxyapatite/β-Tricalcium Phosphate) Bone Graft Substitute: An Experimental Study in Sheep

OBJECTIVE

The aim of the present split-mouth study in sheep was to assess the influence of in situ hardening properties of a biphasic calcium phosphate (BCP) bone graft substitute (BGS) (ratio hydroxyapatite/β-tricalcium phosphate = 60/40) compared with a particulate BGS with the same biphasic core-granule composition without in situ hardening properties on sinus floor augmentation.

MATERIALS AND METHODS

Therefore, bilateral sinus floor augmentation was performed in eight sheep. Poly(lactide-co-glycolide) (PLGA)-coated, in situ hardening biphasic BGS (PLGA-NMP [N-Methyl-2-pyrrolidone]-BCP) was placed at the test site, and a particulate biphasic BGS without PLGA coating (BCP) was used for the contralateral site as a control. Animals were sacrificed after 21 weeks. Sinus augmentation sites were analyzed histologically. The volume was analyzed by computed tomography. Histomorphometric parameters were assessed for the 12 and 21 weeks' time points. Slopes of new bone formation over time were compared with a linear growth regression model.

RESULTS

Bone formation after 12 and 21 weeks of healing was 8.94% (±3.74) and 19.82% (±6.29) for PLGA-NMP-BCP and 7.00% (±2.58) and 14.38% (±4.51) for BCP, respectively. The bone growth rate for PLGA-NMP-BCP was higher than the growth rate for BCP (probability 97.5%). The total fraction of calcified hard tissue (% bone fraction + % biomaterial) was around 46% for both tested biomaterials, 21 weeks after sinus floor augmentation.

CONCLUSION

The in situ hardening BGS (PLGA-NMP-BCP) performed better than the particulate material (BCP) in terms of bone formation rate. The in situ hardening properties of the PLGA-NMP-BCP material mediated by the PLGA coating and NMP solution as plasticizer had no negative influence on the bone formation.

A prospective controlled trial comparing xenograft/autogenous bone and collagen-stabilized xenograft for maxillary sinus augmentation-Complications, patient-reported outcomes and volumetric analysis

OBJECTIVE

Compare maxillary sinus augmentation (MSA) using two different materials-anorganic bovine bone mineral (ABBM) + autogenous bone (AB) (control group) vs. collagen-stabilized ABBM (test group) in terms of complications, patient-reported outcome measures (PROMs) and volumetric analysis.

MATERIALS AND METHODS

Sixty patients underwent sinus augmentation (30 control + 30 test group). Intra- and postoperative complications were recorded. PROMs measured the impact of grafting on daily activities, pain and morbidity. CT scans were used to measure graft volume, ridge height, material selection and degree of contact of graft-to-surrounding sinus walls. Dental implant placement parameters were also recorded.

RESULTS

All complications were minor and did not prevent completion of the augmentation or subsequent implant placement. Schneiderian membrane perforation was the most frequently encountered complication. Both treatment groups reported moderate limitation in the 1st 48 hr post-surgery but little or none by day 3 or 4. Jaw opening, chewing and bruising were significantly higher in the control group. The impact on work and social life was moderate initially but reduced to little or none by the 2nd day. Mild to moderate pain and interference to daily activities were reported for the first 3 days requiring the use of NSAIDs only. A mean graft volume of 1.46 cm³ (±0.77) was calculated in the control group and 1.27 cm³ (±0.65) in the test group. Extent of contact between graft and surrounding sinus walls had a significant impact on bone volume. Shorter (8 mm) implants were utilized more frequently in the test group, which was also more likely to require additional vertical augmentation, but this was not statistically significant.

CONCLUSION

MSA using a lateral wall approach is safe and associated with mild to moderate pain and restrictions to daily activities for 48-72 hr. Patients' reports of morbidity were greater with autogenous bone harvesting. Collagen-stabilized ABBM provides comparable bone volume to AB + ABBM that is sufficient for placement of implants of adequate size with no need for further vertical augmentation. Engaging the surrounding sinus walls had a significant positive impact on graft volume.

Current bone substitutes for implant dentistry

PURPOSE

Alveolar ridge augmentation is essential for success in implant therapy and depends on the biological performance of bone graft materials. This literature review aims to comprehensively explain the clinically relevant capabilities and limitations of currently available bone substitutes for bone augmentation in light of biomaterial science.

STUDY SELECTION

The biological performance of calcium phosphate-based bone substitutes was categorized according to space-making capability, biocompatibility, bioabsorption, and volume maintenance over time. Each category was reviewed based on clinical studies, preclinical animal studies, and in vitro studies.

RESULTS

Currently available bone substitutes provide only osteoconduction as a scaffold but not osteoinduction. Particle size, sensitivity to enzymatic or chemical dissolution, and mechanical properties affect the space-making capability of bone substitutes. The nature of collagen fibers, particulate size, and release of calcium ions influence the biocompatibility of bone substitutes. Bioabsorption of bone substitutes is determined by water solubility (chemical composition) and acid resistance (integrity of apatite structure). Bioabsorption of remnant bone substitute material and volume maintenance of the augmented bone are inversely related.

CONCLUSION

It is necessary to improve the biocompatibility of currently available bone substitutes and to strike an appropriate balance between bioabsorption and volume maintenance to achieve ideal bone remodeling.

Effect of a Particulate and a Putty-Like Tricalcium Phosphate-Based Bone-grafting Material on Bone Formation, Volume Stability and Osteogenic Marker Expression after Bilateral Sinus Floor Augmentation in Humans

This study examines the effect of a hyaluronic acid (HyAc) containing tricalcium phosphate putty scaffold material (TCP-P) and of a particulate tricalcium phosphate (TCP-G) graft on bone formation, volume stability and osteogenic marker expression in biopsies sampled 6 months after bilateral sinus floor augmentation (SFA) in 7 patients applying a split-mouth design. 10% autogenous bone chips were added to the grafting material during surgery. The grain size of the TCP granules was 700 to 1400 µm for TCP-G and 125 to 250 µm and 500 to 700 µm (ratio 1:1) for TCP-P. Biopsies were processed for immunohistochemical analysis of resin-embedded sections. Sections were stained for collagen type I (Col I), alkaline phosphatase (ALP), osteocalcin (OC) and bone sialoprotein (BSP). Furthermore, the bone area and biomaterial area fraction were determined histomorphometrically. Cone-beam CT data recorded after SFA and 6 months later were used for calculating the graft volume at these two time points. TCP-P displayed more advantageous surgical handling properties and a significantly greater bone area fraction and smaller biomaterial area fraction. This was accompanied by significantly greater expression of Col I and BSP and in osteoblasts and osteoid and a less pronounced reduction in grafting volume with TCP-P. SFA using both types of materials resulted in formation of sufficient bone volume for facilitating stable dental implant placement with all dental implants having been in function without any complications for 6 years. Since TCP-P displayed superior surgical handling properties and greater bone formation than TCP-G, without the HyAc hydrogel matrix having any adverse effect on bone formation or graft volume stability, TCP-P can be regarded as excellent grafting material for SFA in a clinical setting. The greater bone formation observed with TCP-P may be related to the difference in grain size of the TCP granules and/or the addition of the HyAc.

Ridge preservation using an in situ hardening biphasic calcium phosphate (β-TCP/HA) bone graft substitute-a clinical, radiological, and histological study

BACKGROUND

Post-Extraction ridge preservation using bone graft substitutes is a conservative technique to maintain the width of the alveolar ridge. The objective of the present study was to evaluate an in situ hardening biphasic (HA/β-TCP) bone graft substitutes for ridge preservation without primary wound closure or a dental membrane.

METHODS

A total of 15 patients reported for tooth extraction were enrolled in this study. Implants were placed in average 5.2 ± 2 months after socket grafting. At this visit, Cone Beam CT (CBCT) images and core biopsies were taken. Implant stability (ISQ) was assessed at the insertion as well as at the day of final restoration.

RESULTS

CBCT data revealed 0.79 ± 0.73 mm ridge width reduction from grafting to implant placement. Histomorphometric analysis of core biopsy samples revealed in average 21.34 ± 9.14% of new bone in the grafted sites. Primary implant stability was high (ISQ levels 70.3 ± 9.6) and further increased until final restoration.

CONCLUSIONS

The results of this study show that grafting of intact post-extraction sockets using a biphasic in situ hardening bone graft substitute results in an effective preservation of the ridge contour and sufficient new bone formation in the grafted sites, which is imperative for successful implant placement.

Subantral Augmentation With Mineralized Cortical Bone Allograft Material: Clinical, Histological, and Histomorphometric Analyses and Graft Volume Assessments

PURPOSE

The aim of this study was to clinically and histologically evaluate the effect of using mineralized cortical bone allograft in sinus lift augmentation and to 3-dimensionally quantify volumetric changes in maxillary sinuses augmented over a 2-year period.

MATERIALS AND METHODS

Eleven patients affected with less than 3 mm of residual ridge were enrolled in the study. After sinus grafting with a mineralized bone allograft, the site was covered with a collagen wound dressing. During implant placement 4 months later, a biopsy was obtained for histological and histomorphometry evaluations. Bone volume changes were also evaluated.

RESULTS

Biopsies showed mature cancellous bone with a predominantly lamellar structure. The well-vascularized intertrabecular spaces were filled with connective tissue and bone marrow. Histomorphometry evaluations revealed a mean 43.76 ± 1.47% of bone marrow, 40.16 ± 1.35% of mineralized bone and 16.59 ± 0.55% of woven bone. The mean of residual particles was 0.47 ± 0.01%. Volumetric measurements showed a mean volume of grafted material 16.24 ± 1.55 cm at T0, 14.48 ± 1.48 cm at T1, and 13.06 ± 1.39 cm at T2. The mean volume retraction was 10.83% of the initial total volume at (T0-T1) and 9.8% at (T1-T2).

CONCLUSIONS

The clinical and histological results indicated that mineralized cortical bone allograft promoted de novo bone formation and can be used for sinus lift procedure.

Volumetric changes of grafted volumes and the Schneiderian membrane after transcrestal and lateral sinus floor elevation procedures: A clinical, pilot study

AIM

To investigate the influence of various surgical techniques for sinus augmentation on the volumetric changes of graft, membrane and the post-operative discomfort.

MATERIALS AND METHODS

Eighteen patients in need of bilateral sinus floor elevation (SFE) were assigned to lateral SFE, transcrestal SFE and intralift procedures. CBCT images taken at baseline, 1 week and 6 weeks were analysed for volumetric changes in graft and Schneiderian membrane. Questionnaires were used to analyse post-op discomfort.

RESULTS

The overall average graft volume obtained after 1 week was 1.87 cm³ (range 0.12-4.72 cm³ ). Volumes decreased after 6 weeks to an overall mean volume of 1.33 cm³ (range 0.10-4.29 cm³ - average decrease of 27.6%). After 6 weeks, the amount of graft volume decreased in every treatment option, ranging from -23.13% for the tSFE, over -24.55% for the lSFE, to -33.71% for the IL. Although all treatment options correspond in an increase in Schneiderian membrane volume, no statistically significant correlation between this increase and loss of graft volume could be obtained for all treatments (p = 0.97).

CONCLUSION

All SFE techniques provided sufficient graft volume for implant treatment. All techniques provoke a partially transient swelling of the Schneiderian membrane. All techniques resulted in a decrease in graft volume after 6 weeks; however, no significant differences were obtained between treatments. Furthermore, no statistical significant correlation between the post-operative swelling of the Schneiderian membrane and reduction in graft volume at 6 weeks could be obtained.

Effect of sex-hormone levels, sex, body mass index and other host factors on human craniofacial bone regeneration with bioactive tricalcium phosphate grafts

Little is known regarding the associations between sex-hormone levels, sex, body mass index (BMI), age, other host factors and biomaterial stimulated bone regeneration in the human craniofacial skeleton. The aim of this study was to elucidate the associations between these factors and bone formation after sinus floor augmentation procedures (SFA) utilizing a bioactive tricalcium phosphate (TCP) bone grafting material. We conducted a prospective study in a human population in which 60 male and 60 female participants underwent SFA and dental implant placement using a staged approach. BMI as well as levels of serum estradiol (E2), total testosterone (TT), and the free androgen index (FAI) were measured by radioimmunoassay and electrochemoluminescent-immunoassay. At implant placement, 6 months after SFA, bone biopsy specimens were harvested for hard tissue histology, the amount of bone formation was evaluated by histomorphometry and immunohistochemical analysis of osteogenic marker expression. The Wilcoxon rank-sum U test, Spearman correlations and linear regression analysis were used to explore the association between bone formation and BMI, hormonal and other host factors. BMI and log E2 were significantly positively associated with bone formation in male individuals (p < 0.05). Histomorphometry revealed trends toward greater bone formation and osteogenic marker expression with non-smokers compared to smokers. In male patients, higher E2 levels and higher BMI enhanced TCP stimulated craniofacial i.e. intramembranous bone repair.

Clinical and Radiological Outcomes of Implants in Osteotome Sinus Floor Elevation with and without Grafting: A Systematic Review and a Meta-Analysis

PURPOSE

To systematically appraise the clinical and radiological outcomes after osteotome sinus floor elevation (OSFE) with or without grafting in the published dental literature.

METHODS

An electronic search was conducted using PubMed, Web of Science, and the Cochrane Central Register of Controlled Trial to identify studies after OSFE from January 1, 1994 to August 30, 2015. The primary outcome was the implant survival rates after OSFE with and without grafting materials.

RESULTS

After search and evaluation of the literature according to the inclusion criteria, 7 studies were included in the review. The random-effect model meta-analysis based on 463 implants in patients without grafting and 415 implants in patients with grafting showed that the risk ratio difference of survival rates was 1.010 (95%CI 0.910, 1.120), which did not reach statistical significance (p = 0.99). The membrane perforation rates ranged from 0% to 10.80%. No significant difference of crestal bone loss was reported between graft and nongraft groups.

CONCLUSIONS

Based on currently available evidence, OSFE techniques with and without grafting were both predictable in the short term. In addition, survival rates of dental implants in OSFE with or without grafting did not show any significant difference in the short term.

Evaluation of Volumetric Changes of Augmented Maxillary Sinus With Different Bone Grafting Biomaterials

Extensive alveolar bone resorption because of pneumatized maxillary sinus is a common problem that limits dental implant placement. Maxillary sinus floor augmentation (MSFA) is an accepted treatment protocol that provides sufficient bone volume. The aim of this study was to evaluate the percentage of graft volume reduction following MSFA using cone beam computed tomography. In this retrospective study, cone beam computed tomography scans of MSFA were measured to evaluate the volume of the grafted sinus with deproteinized bovine bone (DBB), mineralized allograft (MA), or a mixture of MA and demineralized allograft as a composite. The volumetric changes in sinus augmentation between 2 weeks (T-I) and 6 months (T-II) after operation were analyzed. Thirty-nine patients were included in this study. The average percent volume reduction was 8.14 ± 3.76%, 19.38 ± 9.22%, and 24.66 ± 4.68% for DBB, MA, and composite graft, respectively. A significant graft volume reduction was found between T-I and T-II for all groups (P < 0.01). The DBB group showed the least volume reduction (P < 0.01). Biomaterials can influence the bone graft volume change before implant placement. Deproteinized bovine bone may offer greater volume stability during healing than mineralized and composite allografts.

Sinus lift: 3 years follow up comparing autogenous bone block versus autogenous particulated grafts

Background/purpose

The aim of this prospective randomized controlled clinical trial was to compare vertical bone gain and bone resorption after sinus graft procedures performed either with particulate or with autogenous bone block.

Material and methods

Forty-one patients underwent sinus graft procedures with autogenous bone. They were randomly assigned to one group. The first group of 22 patients was treated with autogenous bone block with or without particulated bone, while in the second group of 19 patients sinus floor elevation was performed only with particulated autogenous bone. Linear measurements were recorded before surgery with a computed tomography scan at surgery and at 36 months after sinus lift grafting with a second computed tomography scan. To detect statistical differences Student t test was applied. Differences were considered significant if P values were < 0.05.

Results

There was a statistically significant difference in bone gain for the group treated with bone block grafts.

Conclusion

As a general clinical guideline the clinician should prefer, wherever feasible, en-block bone grafts for sinus floor augmentation procedures.

Long-term Evaluation of Peri-implant Bone Level after Reconstruction of Severely Atrophic Edentulous Maxilla via Vertical and Horizontal Guided Bone Regeneration in Combination with Sinus Augmentation: A Case Series with 1 to 15 Years of Loading

BACKGROUND

To the best of the authors' knowledge, there is very limited clinical data on the outcomes of simultaneous guided bone regeneration (GBR) for horizontal and/or vertical bone gain for the reconstruction of severely atrophic edentulous maxilla. Therefore, the purpose of the clinical series presented herein was to clinically evaluate long-term horizontal and vertical bone gain, as well as implant survival rate after reconstruction of severely atrophic edentulous maxillary ridges.

MATERIAL AND METHODS

Sixteen patients (mean age: 64.6 ± 14.6 years of age) were consecutively treated for vertical and/or horizontal bone augmentation via GBR in combination with bilateral sinus augmentation utilizing a mixture of autologous and anorganic bovine bone. Implant survival, bone gain, intraoperative/postoperative complications and peri-implant bone loss were calculated up to the last follow-up exam.

RESULTS

Overall, 122 dental implants were placed into augmented sites and have been followed from 12 to 180 months (mean: 76.5 months). Implant survival was 100% (satisfactory survival rate of 97.5%). Mean bone gain was 5.6 mm (max: 9 mm; min: 3 mm) While vertical bone gain was 5.1 ± 1.8 mm; horizontal bone gain was 7.0 ± 1.5 mm. No intraoperative/postoperative complications were noted. Mean peri-implant bone loss values were consistent within the standards for implant success (1.4 ± 1.0 mm). At patient-level, only one patient who had three implants presented with severe peri-implant bone loss.

CONCLUSION

Complete reconstruction of an atrophied maxilla can be successfully achieved by means of guided bone regeneration for horizontal and/or vertical bone gain including bilateral sinus augmentation using a mixture of anorganic bovine bone and autologous bone.

ß-Tricalcium Phosphate Implants in the Surgical Treatment of Empty Nose Syndrome

The objective of this study was to assess the efficacy and morbidity of a β-tricalcium phosphate implant in the treatment of empty nose syndrome after turbinectomy. Only patients with a history of inferior turbinectomy and a complaint of permanent paradoxical nasal obstruction were included. β-Tricalcium phosphate ceramic implants were implanted under the mucoperiosteal plane of the lateral nasal wall to replace the head of the inferior turbinate. Symptoms and quality of life were assessed by 2 questionnaires: the Nasal Obstruction Symptom Evaluation and Rhinosinusitis Quality of Life. Fourteen patients were included. The mean follow-up was 19.4 ± 13.4 months. Scores for the Nasal Obstruction Symptom Evaluation and Rhinosinusitis Quality of Life (frequency, bothersomeness, and impact) significantly improved after surgery (respectively, 73.9 ± 21.8 to 34.6 ± 28.6, 44.6 ± 17.1 to 34.8 ± 20.3, 43.6 ± 22.4 to 70.7 ± 21.5, and 59.9 ± 21.1 to 27.2 ± 25.3; P < .05). The use of ß-tricalcium phosphate seems efficient to repair empty nose syndrome by endonasal microplasty and shows a low complication rate.

Long-term radiographic assessment of maxillary sinus floor augmentation using beta-tricalcium phosphate: analysis by cone-beam computed tomography

Background

The long-term stability of maxillary sinus floor augmentation with β-TCP remains largely unknown. We report the long-term assessment of volumetric changes in maxillary sinus floor augmentation with β-TCP by cone-beam computed tomography (CBCT).

Methods

The subjects included 30 patients who underwent maxillary sinus floor augmentation using β-TCP and 58 implant placement for unilateral maxillary defect, simultaneously. Volumetric changes in β-TCP and the height of peri-implant bone were analyzed by CBCT.

Results

In all patients, the mean volume of the grafted bone decreased from immediately after implant placement to 6 months after implant placement (75.6 % reduction rate); it decreased further at 2.5 years after implant placement (54.9 % reduction rate). The mean of the height from the implant tip to the maxillary sinus floor was 2.00 ± 1.51 mm, 0.73 ± 1.33 mm, and −0.72 ± 1.11 mm immediately, 6 months, and 2.5 years after implant placement, respectively. The implant tip protruded beyond the maxillary sinus floor in approximately 70 % of the implants (41/58 implants) at 2.5 years after surgery. During the observation period, the implant survival rate was 100 %.

Conclusions

The radiographic analysis by CBCT is considerably more advanced than previous radiographic examinations. Although maxillary sinus pneumatization continues to progress ≥1 year after maxillary sinus floor augmentation with β-TCP, it stabilizes 3 years after surgery.

Late-term healing in an augmented sinus with different ratios of biphasic calcium phosphate: a pilot study using a rabbit sinus model

PURPOSE

The aim of this pilot study was to determine the osteoconductivity and dimensional stability of augmented sinuses using different ratios of biphasic calcium phosphate (BCP) in a rabbit sinus model.

METHODS

Each sinus of New Zealand white rabbits (2.5-3.5 kg) was assigned to one of two groups: BCP with a hydroxyapatite to β-tricalcium phosphate (HA:β-TCP) ratio of 70:30 (group TCP30) and BCP with an HA:β-TCP ratio of 30:70 (group TCP70). After preparing a window in the antral wall of a sinus, the Schneiderian membrane was elevated, and the applicable material was grafted. A fluorochrome calcein green was injected five days before euthanizing the animals at four months post-surgery. The specimens were analyzed histologically, histomorphometrically, and by using micro-computed tomography (micro-CT).

RESULTS

Micro-CT analysis revealed that the total augmented volume and the new bone volume did not differ significantly between the two groups whereas the resorption of materials was greater in the TCP70 group. The trabecular thickness, number, and separation also did not differ significantly between the two groups. Histomorphometrically, the areas of total augmentation, new bone, and residual material, as well as the ratio of new-bone-material contact did not differ significantly between the groups. Histologically, the residual particles were more scattered in the TCP70 group than in the TCP30 group. The fluorescence of the calcein green did not differ notably between the two groups.

CONCLUSIONS

The osteoconductivity and dimensional stability of the two BCPs with different ratios tested in this study were comparable after four months of healing. Therefore, we conclude that both BCPs show promise as a bone substitute for sinus augmentation.

Sinus Floor Augmentation Using Straumann® BoneCeramic™ and Bio-Oss® in a Split Mouth Design and Later Placement of Implants: A 5-Year Report from a Longitudinal Study

BACKGROUND

Straumann® BoneCeramic™ is a synthetic biphasic calcium phosphate (BCP) aimed for sinus floor augmentation. Long-term follow-up of implants placed in BCP after sinus augmentation is still missing.

PURPOSE

The primary aim of the study was to compare survival rates and marginal bone loss of Straumann SLActive implants placed in either BCP (test) or Bio-Oss® (DBB) (control) after sinus floor augmentation. The secondary aim was to calculate graft sinus height at different time points.

MATERIALS AND METHODS

Bilateral sinus floor augmentation was performed in a split mouth model. Eleven patients (mean age 67 years) received 100% BCP on one side and 100% DBB on the contralateral side. After 8 months of graft healing, 62 Straumann SLActive implants were placed. After 5 years of functional loading (6 years after augmentation) of implants, marginal bone levels and grafted sinus height were measured, and implant survival and success rates were calculated.

RESULTS

After 5 years of loading, all prosthetic constructions were in function although two implants were lost in each grafting material. The overall implant survival rate was 93.5% (91.7% for BCP, 91.3% for DBB, and 100% for residual bone). The success rates were 83.3% and 91.3% for BCP and DBB, respectively. There was no statistically significant difference in mean marginal bone level after 5 years between BCP (1.4 ± 1.2 mm) and DBB (1.0 ± 0.7 mm). Graft height reduction (GHR) after 6 years was limited to 6.6% for BCP and 5.8% for DBB.

CONCLUSION

In this limited RCT study, the choice of biomaterial used for sinus floor augmentation did not seem to have any impact on survival rates and marginal bone level of the placed implants after 5 years of functional loading and GHR was minimal.

Evaluation of Three-Dimensional Volumetric Changes After Sinus Floor Augmentation with Mineralized Cortical Bone Allograft

AIM

The aim of this retrospective study was to quantify three-dimensional (3D) volumetric bone changes over a two-year period in maxillary sinuses augmented with a mineralized cortical bone allograft material (MCBA) material.

PATIENTS AND METHODS

Eleven patients (6 males and 5 females) with mean of age of 51.6 (range: 46-61) years were treated to increase the vertical dimension of the alveolar crest by maxillary sinus floor augmentation procedure. Study data were collected from patient records and by analyzing preoperative radiographs and cone beam computed tomography (CBCT) scans taken within the first two weeks after maxillary sinus lift (T0), immediately before implant placement four months after grafting (T1), and after one year of implant loading (T2). All DICOM-formatted images were rendered into volumetric images using software that automatically calculated the volume of the grafted material in cubic centimeters.

RESULTS

Mean graft volume was 16.24 ± 1.54 cm(3) at T0, 14.48 ± 1.48 cm(3) at T1 and 13.06 ± 1.39 cm(3) at T2. Mean volume retraction resulted in 1.76 ± 0.34 cm(3) ΔV1 (T0-T1) and 1.42 ± 0.4 cm(3) ΔV2 (T1-T2) and was 10.83 % of the initial total volume at (T0-T1) and 9.8 % of the total volume (T1-T2).

CONCLUSION

The present retrospective investigation demonstrated a 20.63 % decrease in graft volume. Volumetric 3D assessment of CBCT scans with the selected software appeared to be a promising approach to quantifying long-term changes in the grafted area.

High-Resolution Three-Dimensional Computed Tomography Analysis of the Clinical Efficacy of Cultured Autogenous Periosteal Cells in Sinus Lift Bone Grafting

Background and Purpose

Sinus lift (SL) using cultured autogenous periosteal cells (CAPCs) combined with autogenous bone and platelet‐rich plasma (PRP) was performed to evaluate the effect of cell administration on bone regeneration, by using high‐resolution three‐dimensional computed tomography (CT).

Materials and Methods

SL with autogenous bone and PRP plus CAPC [CAPC(+)SL] was performed in 23 patients. A piece of periosteum taken from the mandible was cultured in M199 medium with 10% fetal bovine serum (FBS) for 6 weeks. As control, 16 patients received SL with autogenous bone and PRP [CAPC(−)SL]. Three‐dimensional CT imaging was performed before and 4 months and 1 year after SL, and stratification was performed based on CT numbers (HUs) corresponding to soft tissue and cancellous or cortical bone.

Results

The augmented bone in CAPC(+)SL revealed an increase in HUs corresponding to cancellous bone as well as a decrease in HUs corresponding to grafted cortical bone. In addition, HUs corresponding to cancellous bone in the graft bed were increased in CAPC(+)SL but were decreased in CAPC(−)SL. Insertion torque during implant placement was significantly higher in CAPC(+)SL.

Conclusion

By promoting bone anabolic activity both in augmented bone and graft bed, CAPCs are expected to aid primary fixation and osseointegration of implants in clinical applications.