Objectives: Test the hypothesis of no difference in the volumetric stability of the grafting material following maxillary sinus floor augmentation with autogenous bone graft compared with composite grafting material or bone substitute alone applying the lateral window technique. Material and methods: MEDLINE (PubMed), Embase, Cochrane library an...
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Context 1... percentage of three-dimensional volumetric changes of the grafting material following MSFA are presented below including a short summary and the results are outlined in Table 2. None of the included studies assessed the correlation between volumetric changes of the grafting material and predictive parameters, why this outcome measure is not described. ...
The purpose of this clinical study is to evaluate the safety and preliminary efficacy of autologous freeze-drying platelet-rich plasma (FD-PRP) on bone regeneration in maxillary sinus floor augmentation as a preliminary pilot study. Five patients that required sinus floor augmentation to facilitate the placement of dental implants participated in t...
... The dimensional modification of a maxillary sinus graft around implants has long been a subject of investigation, as graft stability may represent one of the prognostic factors for long-term implant success [17,18]. Over the years, several clinical studies investigated radiographic changes of graft height and volume in sinuses augmented using different grafting materials . Autogenous bone grafts were found to present unpredictable resorption , while other popular bone substitutes like deproteinized bovine bone showed very slow or no resorption along several years [27,28]. ...
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.
... In fact, graft stability may represent an important prognostic factor for implant success in the long term [38,39]. Several clinical and radiographic studies have evaluated graft height and volume changes in maxillary sinuses augmented with various types of grafting materials . While autogenous bone grafts were found to have unpredictable resorption , other common bone substitutes such as deproteinized bovine bone matrix demonstrated extremely slow or no resorption at all after several years [48,49]. ...
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.
... Furthermore, while complete resorption and replacement of the graft by a new bone formation is desirable, in some cases, a long-lasting scaffold was crucial to support osteointegrated implants . Regarding the AU reabsorption, a recent meta-analysis by Starch-Jensen et al.  and a systematic review by Shanbhag et al.  confirmed our results. Unfortunately, in the present work, no meta-analysis of graft shrinkage could be performed as there were no more than two studies for each type of comparison between materials. ...
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.
Introduction: Due to the extensive number of studies developed on periodontal pathologies and the clinical need generated to correct bonvze defects, we have carried out an Overview of systematic reviews using the FRISBEE methodology. Material and Methods: Through this study we expect to bridge the knowledge gap generated regarding the clinical question on the effectiveness of autologous bone substitutes and xenografts in maxillary and mandibular bone defects. Results: For this study, we carried out a systematic search in Epistemonikos and PubMed, we included 3 systematic reviews and 5 primary studies included in these reviews to extract their data. We analyzed data using RevMan 5.4. and GRADEpro. Assessed outcomes included: bone gain [MD 0.06 mm lower (0.26 lower to 0.14 higher)] and bone resorption [MD 0.03 mm higher (0.12 lower to 0.18 higher)], where no significant differences were found between the study groups. The certainty of the evidence was moderate for both outcomes. Bone length and bone density outcomes were not measured or reported in the included studies. Conclusion: We concluded that there are no significant clinical differences between the application of autologous bone grafts and xenografts for bone defects correction for the assessed outcomes, therefore, these biomaterials should be applied at the discretion of the clinician and according to the needs and preferences of patients.
Customized bone replacement structures offer the potential to build up missing bone areas. However, additive manufacturing of calcium phosphate cement (CPC) structures is limited due to the material behavior. The aim is to separate the functionalization and shaping. Thus, prefabricated CPC-prefabs, which show different porosity as functionalization, are to be manufactured additively. The individual shaping will be carried out by milling (CAD/CAM). Several CPC-prefabs are developed, which differ in the mapping of the transition geometry from porous to dense phase as well as in the overall size. Therefore, categorized datasets of mandibular scans are analyzed and the cross-sectional contour of the bone is determined. Mathematical regression is used to determine a parametrically described average contour, which is used to design the prefab models. First single phase prefab demonstrators have been additively manufactured and subjected to initial milling tests. The feasibility in principle of the intended process has thus been demonstrated.
For an ergonomic and healthy sitting posture, the distribution of the seat load in the contact zone through a soft seat cushion is essential. Conventional polyurethane (PUR) foams have only a very limited ability to adapt the distribution of the seat load in the seat cushion to the individual person. In this paper, a potential analysis is conducted to show the extent to which a replacement model for PUR foams can be realized using thermoplastic polyurethane (TPU) materials in the fused-deposition modeling (FDM) process. Based on fundamental experiments and consideration of manufacturing restrictions, suitable structure families and types are investigated and characterized. The characterization is based on standards for foam testing. Grading and design parameters are presented for the use of the foam replacement model in cushioned units. This allows the replacement of PUR foam and also a customer-specific hardness grading in the context of a mass customization process chain.
Severe atrophic posterior maxillary ridge (residual bone height < 3 mm) could be a challenging situation to place dental implants. Several treatment options have been proposed, but some of them may require advanced surgical skills to achieve best results. In this article, we present a novel and easier technique to allow implant placing in localized areas of severe atrophy. In a first step, a 4.5-length extra-short (unloaded) implant is placed after a transcrestal maxillary sinus floor augmentation (MSFA). After the gained apical bone consolidation, this “temporary implant” is atraumatically removed and a longer and wider definitive implant is placed to support the definitive single restoration. The case of a 45-year-old female treated with this approach is also presented. The patient suffered a severe resorption in the upper right molar area after a tooth extraction. Four months after the “temporary implant” placement and MSFA grafting with plasma rich in growth factors and autologous bone, 3 mm of dense apical bone gain could be observed. In a second surgical time, the 4.5 mm-length “temporary implant” was removed, and a 5.5 mm-length “definitive implant” was placed. This second implant was placed in a denser type 1 (1,000 Hounsfield Unit) new formed apical bone. Four months later, the implant was loaded with a screw-retained crown over a transepithelial (intermediate abutment). After 1-year follow-up, the implant was in health and no mechanical or biological complications were noticed. The satisfactory results of this case encourage the realization of new studies to elucidate its reproducibility.
This systematic review aimed to evaluate computed tomographic scans for volumetric bone gain following lateral sinus floor augmentation of the atrophic posterior maxilla after the use of various bone-grafting materials using. The databases MEDLINE, EMBASE, CINAHL, Cochrane Central Registry of Controlled Trials (CENTRAL), and SCOPUS were used for a comprehensive search for all potentially eligible randomized controlled trials (RCTs), without language restrictions, from the beginning of each database until June 2021. The predictor variables for this review were autogenous bone (AB), allografts (AG), xenografts (XG), alloplastic bone (AP), which were assessed individually, and in combination with the inclusion of growth factors with XGs. The outcome variable was the graft volume on cone beam computed tomographic (CBCT) scans. Seven RCTs with a short-term observation period were included. Topographical analyses of all graft materials identified a volumetric reduction at 6 months post-grafting, compared to values immediately after graft placement. The volumetric reduction occurred regardless of the type of bone-grafting material. The largest volumetric gain over baseline, pre-graft values, was found with the AG+XG group. Autografts, the present gold standard bone-graft, showed a high resorption rate and inferior volumetric increase when compared to alternative grafting combinations. AG and XG also showed a significant difference with less volumetric gain than AP and their combinations. No difference was detected between AP and AG+AP. However, there was significantly less volumetric gain for AP alone compared AG+XG and XG-growth factors combinations. As a result, these findings suggest significant advantages to new bone formation using grafting materials in combination. To achieve a better understanding of topographical variables related to various grafting materials, more clinically focused RCTs, with sufficient statistical power to control for confounding factors, are needed.
Bone-grafting biological materials are commonly used to increase the height of the alveolar bone in the maxillary posterior region during maxillary sinus floor augmentation. However, there has been little research on the development of an injectable bone-grafting material with bacteriostatic, angiogenic, and osteogenic properties. In this work, we developed a triple-functional vancomycin/deferoxamine/dexamethasone (Van/DFO/Dex) liposome–hydrogel composite with desirable injectability. The release kinetics confirmed orderly sustained release of Van (a bacteriostat), DFO (a vascularised small molecule), and Dex (an osteogenic small molecule). In vitro findings demonstrated the favourable cytocompatibility and antibacterial ability of this composite against Staphylococcus aureus. Additionally, the angiogenic ability of human umbilical vein endothelial cells and osteogenic differentiation activity of MC3T3-E1 cells were enhanced. An in vivo bacteriostasis assay and rabbit maxillary sinus floor augmentation model corroborated the enhanced bacteriostasis and vascularised bone regeneration properties of this functionalised composite. Overall, the favourable injectability to be fit for the minimally invasive procedure, locally sustained release property, and prominent biological functions underscore the clinical potential of Van/DFO/Dex as an ideal bone-grafting material for irregular bone defect repairs, such as maxillary sinus floor augmentation.
Objectives: To retrospectively evaluate whether repositioning the bone window leads to a better outcome of three-dimensional sinus augmentation in lateral sinus floor elevation (LSFE) with simultaneous implant placement. Methods: 34 patients with a total of 40 implants (14: test group, 26: control group) receiving LSFE with simultaneous implant placement were included in this retrospective research. CBCT images were taken before surgery, immediately and 6 months after surgery. The two-dimensional augmentation parameters, including apical bone height (ABH), endo-sinus bone gain (ESBG), and palatal/buccal bone height (PBH/BBH), and three-dimensional parameters, including augmentation volume (AV) and palatal/buccal augmentation volume (PAV/BAV), were measured. The lateral defect length (LDL) and lateral window length (LWL) were also measured to evaluate the lateral antrostomy recovery. Results: At the 6-month follow-up, the reduction rates at ABH, ESBG, and BBH of the test group (ABH: 10.41% ± 30.30%, ESBG: 2.55% ± 8.91%, BBH: 2.50% ± 8.65%) were significantly lower than those of the control group (ABH: 25.10% ± 22.02%, ESBG: 11.47% ± 9.79%, BBH: 7.10% ± 5.37%; p < .05). In addition, the test group showed better three-dimensional augmentation stability on the buccal side (BAV reduction: 15.51% ± 10.86% vs. 27.15% ± 12.61%; p < .05). Moreover, the LDL/LWL ratio of the test group was significantly lower than that of the control group (p < .05). Conclusion: Within the limitations of this study, repositioning of the bone window in LSFE with simultaneous implant placement could contribute to endo-sinus augmentation stability on the buccal side at the 6-month follow-up. Moreover, it would also facilitate recovery of the lateral antrostomy defect.