Maxillary Sinus Floor Augmentation with Autogenous Bone Graft Alone Compared with Alternate Grafting Materials: a Systematic Review and Meta-Analysis Focusing on Histomorphometric Outcome

Maxillary sinus floor augmentation with autogenous bone graft compared with composite grafts: A one-year single-blinded randomized controlled trial

OBJECTIVE

The objective was to assess the one year implant treatment outcome and patient-related outcome measures (PROMs) following maxillary sinus floor augmentation (MSFA) with autogenous bone graft (ABG) from the zygomatic buttress (control) compared with 1:1 mixture of ABG and anorganic porcine bone mineral (APBM) (Test I) or biphasic bone graft material (BBGM) (Test II).

MATERIALS AND METHODS

Sixty healthy patients (34 females, 26 males) were randomly allocated to either control or test groups. Outcome measures included survival of suprastructures and implants, implant stability quotient, health status of peri-implant tissue, peri-implant marginal bone loss, frequency of complications, and PROMs using Oral Health Impact Profile-14 combined with questionnaire assessing patient perception of peri-implant soft tissue, prosthetic solution, implant function, and implant treatment outcome using visual analogue scale. Mean differences were expressed with standard deviation and 95% confidence interval. Level of significance was .05.

RESULTS

All suprastructures and implants were well-functioning after one year of functional implant loading. There was no significant difference between control and test groups in any of the applied outcome measures. The implant stability significantly increased from implant placement to abutment connection within all groups (p < .001). High patient satisfaction and significant improvement in oral health-related quality of life was also reported within all groups.

CONCLUSION

This study demonstrates that MSFA with composite grafts containing minimal amounts of ABG reveals comparable implant treatment outcomes as compared with ABG alone, after one year of functional implant loading. Extensive ABG harvesting in conjunction with MSFA therefore seems not to be needed.

A novel Chilean salmon fish backbone-based nanoHydroxyApatite functional biomaterial for potential use in bone tissue engineering

Introduction

Given the ensuing increase in bone and periodontal diseases and defects, de novo bone repair and/or regeneration strategies are constantly undergoing-development alongside advances in orthopedic, oro-dental and cranio-maxillo-facial technologies and improvements in bio-/nano-materials. Indeed, there is a remarkably growing need for new oro-dental functional biomaterials that can help recreate soft and hard tissues and restore function and aesthetics of teeth/ dentition and surrounding tissues. In bone tissue engineering, HydroxyApatite minerals (HAp), the most stable CaP/Calcium Phosphate bioceramic and a widely-used material as a bone graft substitute, have been extensively studied for regenerative medicine and dentistry applications, including clinical use. Yet, limitations and challenges owing principally to its bio-mechanical strength, exist and therefore, research and innovation efforts continue to pursue enhancing its bio-effects, particularly at the nano-scale.

Methods

Herein, we report on the physico-chemical properties of a novel nanoHydroxyApatite material obtained from the backbone of Salmon fish (patent-pending); an abundant and promising yet under-explored alternative HAp source. Briefly, our nanoS-HAp obtained via a modified and innovative alkaline hydrolysis-calcination process was characterized by X-ray diffraction, electron microscopy, spectroscopy, and a cell viability assay.

Results and Discussion

When compared to control HAp (synthetic, human, bovine or porcine), our nanoS-HAp demonstrated attractive characteristics, a promising biomaterial candidate for use in bone tissue engineering, and beyond.

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.

Efficacy of bone ring grafts for the reconstruction of alveolar ridge deficiencies: A systematic review. Part I: Clinical trials

BACKGROUND

Bone ring (BR) grafts have been introduced to reconstruct alveolar ridge defects with simultaneous implant placement, but its clinical effectiveness remains undetermined. This systematic review aimed to comprehensively investigate BR grafts in diverse scenarios of ridge defect with simultaneous or staged implant placement.

METHODS

Electronic retrieval of MEDLINE, Embase, Cochrane Library(CENTRAL), Web of Science, Scopus, and citation search until August 3, 2023, was used to identify relevant clinical articles that utilized BR grafts for ridge defect reconstruction. The quality of evidence in the studies reviewed was assessed with the Joanna Briggs Institute Critical Appraisal tool. The protocol was registered in Prospective Register of Systematic Reviews (CRD42023453943).

RESULTS

Fourteen studies with 251 BRs were identified, of which 8 studies were for alveolar ridge augmentation, 4 studies were for extraction socket augmentation, and 2 studies were for sinus floor elevation. Reported sources of BRs included autografts, allografts, and xenografts. The follow-up period ranged from 4 months to 4.7 years. Regarding the primary outcomes, the utilization of BR grafts demonstrated favorable bone gain along with acceptable graft absorption and marginal bone loss. Regarding the secondary outcomes, satisfactory bone mineral density and implant stability were confirmed, accompanied by a recorded incidence of postoperative complications (20 cases) and an implant failure rate of 5.58%.

CONCLUSIONS

BR grafting with simultaneous or staged implant insertion is an effective approach for reconstructing alveolar ridge deficiencies. The BR grafts demonstrate favorable bone remodeling and osteointegration with the alveolar bone and implant; however, its success may be compromised by complications. Future studies should further investigate the clinical efficacy of BR grafting comparing to other bone augmentation techniques in diverse scenarios.

Assessment of the osteogenic effect after maxillary sinus floor elevation and simultaneous implantation with or without bone grafts by analyzing trabecular bone parameters: a retrospective study

OBJECTIVE

The aim of this population-based retrospective study was to compare the osteogenic effect of newly formed bone after maxillary sinus floor elevation (MSFE) and simultaneous implantation with or without bone grafts by quantitatively analyzing trabecular bone parameters.

METHODOLOGY

A total of 100 patients with missing posterior maxillary teeth who required MSFE and implantation were included in this study. Patients were divided into two groups: the non-graft group (n=50) and the graft group (n=50). Radiographic parameters were measured using cone beam computed tomography (CBCT), and the quality of newly formed bone was analyzed by assessing trabecular bone parameters using CTAn (CTAnalyzer, SkyScan, Antwerp, Belgium) software.

RESULTS

In the selected regions of interest, the non-graft group showed greater bone volume/total volume (BV/TV), bone surface/total volume (BS/TV), trabecular number (Tb. N), and trabecular thickness (Tb. Th) than the graft group (p<0.001). The non-graft group showed lower trabecular separation (Tb. Sp) than the graft group (p<0.001). The incidence of perforation and bleeding was higher in the graft group than in the non-graft group (p<0.001), but infection did not significantly differ between groups (p>0.05). Compared to the graft group, the non-graft group showed lower postoperative bone height, gained bone height and apical bone height (p<0.001).

CONCLUSION

MSFE with and without bone grafts can significantly improve bone formation. In MSFE, the use of bone grafts hinders the formation of good quality bone, whereas the absence of bone grafts can generate good bone quality and limited bone mass.

Allogeneic versus autogenous shell technique augmentation procedures: a prospective-observational clinical trial comparing surgical time and complication rates

OBJECTIVES

Autogenous and allogeneic blocks for shell augmentation of the jaw have shown comparable results. This observational clinical study aimed to compare both materials for shell augmentation concerning surgery time and intra- and postoperative complications.

MATERIAL AND METHODS

Bone augmentation with the shell technique using autogenous or allogenous bone was performed in 117 patients with segmental jaw atrophy. The primary study parameter was the surgical time, comparing both materials. Subsequently, intra- and postoperative complications were recorded.

RESULTS

Allogeneic (n = 60), autogenous (n = 52), or both materials (n = 5) were used. The use of allogeneic material led to a significantly shorter operation time (p < 0.001). A more experienced surgeon needed significantly less time than a less experienced surgeon (p < 0.001). An increasing number of bone shells (p < 0.001), an additional sinus floor elevation, and intraoperative complications also significantly increased the operation time (p = 0.001). Combining allogeneic and autogenous shells (p = 0.02) and simultaneous sinus floor elevation (p = 0.043) significantly impacted intraoperative complications. No correlations were found between the included variables for postoperative complications (all p > 0.05). In total, 229 implants were inserted after a healing time of 4-6 months, with a survival of 99.6% after a mean follow-up duration of 9 months.

CONCLUSIONS

Compared to the autogenous technique, allogeneic shell augmentation has a shorter surgical time and a similar rate of intra- and postoperative complications as autogenous bone. Together with its promising clinical results, this technique can be recommended.

Bone regeneration after maxillary sinus floor augmentation with different ratios of autogenous bone and deproteinized bovine bone mineral an in vivo experimental study

OBJECTIVE

Test the hypothesis of no difference in bone regeneration after maxillary sinus floor augmentation (MSFA) with different ratios of iliac or mandibular autogenous bone (AB) graft and deproteinized bovine bone mineral (DBBM).

MATERIALS AND METHODS

Forty minipigs were randomly allocated to bilateral MSFA using: (A) 100% AB, (B) 75% AB and 25% DBBM, (C) 50% AB and 50% DBBM, (D) 25% AB and 75% DBBM, or (E) 100% DBBM. The animals were euthanized 12 weeks after surgery. Percentage of bone, non-mineralized tissue, and residual DBBM were estimated by histomorphometric analysis in a randomly selected region of interest and summarized as mean percentage with 95% confidence interval (CI).

RESULTS

Mean percentage of bone following MSFA with iliac or mandibular AB graft was: (A) 55.5% and 64.2%, (B) 60.3% and 61.6%, (C) 54.4% and 52.1%, (D) 51.8% and 53.1%, and (E) 47.6%, respectively. There was a significant trend toward a higher percentage of bone, with a higher ratio of AB within the graft (p < .01), regardless of the origin of AB graft (iliac or mandible).

CONCLUSIONS

The hypothesis was rejected since percentage of bone was significantly increased with larger proportions of AB within the graft. Consequently, AB or a mixture of AB and diminutive quantities of DBBM seem to be the preferred graft for MSFA based solely on histomorphometric assessment. However, it should be emphasized that newly formed bone and residual AB graft particles could not be distinguished by the applied histologic procedure.

Maxillary Sinus Floor Augmentation With Allograft Alone Compared With Alternate Grafting Materials: A Systematic Review and Meta-Analysis

A meta-analysis of scientific literature was conducted to ascertain the superiority between allografts and other regenerative grafts for maxillary sinus floor augmentation (MSFA). Review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines and registered in PROSPERO-CRD42023392766. Electronic databases like PubMed, Google scholar and Ebsco Host were searched from 2000 to December 2022 for studies reporting MSFA using allografts or other regenerative grafts. Quality assessment of included studies was evaluated using the Cochrane risk of bias (ROB)-2 tool for randomized controlled trials through its domains. Risk of bias summary graph and ROB summary applicability concern were plotted using RevMan software version 5.3. The standardized mean difference was used as a summary statistic measure with random effect model and P value <0.05 as statistically significant. Four studies fulfilled the eligibility criteria and were included in qualitative synthesis, of which all 4 studies were suitable for meta-analysis. Pooled estimate through standardized mean difference signifies that new bone formation was more or less similar for both graft materials, whereas regenerative grafts showed more residual bone grafts (P>0.05). Publication bias through funnel plot showed symmetric distribution with the absence of systematic heterogeneity. Both allografts and other regenerative grafts are equally effective in the MSFA in terms of new bone formation, whereras regenerative grafts showed more residual bone grafts. Furthermore, randomized controlled trials are required to establish evidence in outcomes involving sinus floor augmentation and different graft materials.

Techniques on vertical ridge augmentation: Indications and effectiveness

Vertical ridge augmentation techniques have been advocated to enable restoring function and esthetics by means of implant-supported rehabilitation. There are three major modalities. The first is guided bone regeneration, based on the principle of compartmentalization by means of using a barrier membrane, which has been demonstrated to be technically demanding with regard to soft tissue management. This requisite is also applicable in the case of the second modality of bone block grafts. Nonetheless, space creation and maintenance are provided by the solid nature of the graft. The third modality of distraction osteogenesis is also a valid and faster approach. Nonetheless, owing to this technique's inherent shortcomings, this method is currently deprecated. The purpose of this review is to shed light on the state-of-the-art of the different modalities described for vertical ridge augmentation, including the indications, the step-by-step approach, and the effectiveness.

Two-Step Progressive Transcrestal Sinus Augmentation Using a 4.5 mm Unloaded Implant as a "Temporary Implant" in Highly Atrophic Ridge: Case Report

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.

A Biomechanical Analysis of the Influence of the Morfology of the Bone Blocks Grafts on the Transfer of Tension or Load to the Soft Tissue by Means of the Finite Elements Method

Edentulism produces resorption of alveolar bone processes, which can complicate placement of dental implants. Guided bone regeneration techniques aim to recover the volume of bone. These treatments are susceptible to the surgical technique employed, the design of the autologous block or the tension of the suture. These factors can relate to major complications as the lack of primary closure and dehiscence. The present study, using finite element analysis, aimed to determine differences in terms of displacement of the oral mucosa, transferred stress according to Von Mises and deformation of soft tissue when two block graft designs (right-angled and rounded) and two levels of suture tension (0.05 and 0.2 N) were combined. The results showed that all the variables analyzed were greater with 0.2 N. Regarding the design of the block, no difference was found in the transferred stress and deformation of the soft tissue. However, displacement was related to a tendency to dehiscence (25% greater in the right-angled/chamfer design). In conclusion different biomechanical behavior was observed in the block graft depending on the design and suture tension, so it is recommended to use low suture tension and rounded design. A novel finite element analysis model is presented for future investigations.

Osseointegration Levels of Implants Placed With Allogenic and Xenogenic Bone Ring: An Experimental Biomechanical Analysis

This in vivo study aimed to do a biomechanical analysis of the early period bone-implant connection of titanium implants simultaneously inserted with xsenogenic and allogenic bone ring. In this study, 28 Sprague Dawley female rats were used. Four rats were killed to obtain an allogenic bone ring, and after this, the remaining rats were divided into control (n=8), xsenogenic (n=8), and allogenic (n=8) bone ring groups. Titanium-machined surfaced implants were integrated right tibias of the rats. In controls, only implants were integrated into right tibias. In the greft groups, the implants were integrated simultaneously with bone rings. After 2 weeks of the experimental period, the rats were killed ,and titanium implants and surrounding bone tissues were removed for biomechanic analysis. After biomechanical reverse torque analysis bone-implant connection was determined as Newton/cm2; in controls 3.26 (1.2 to 4.5), in allogenic ring group 3.37 (2 to 4.4), in xsenogenic ring group 5.93 (2.8 to 10). Statistically significant differences were not detected between the groups (P>0.05). Within the limitation of this study, both allogenic and xsenogenic bone grafts could be successfully used in bone augmentation in implant surgery.

Managing the severely atrophic maxilla: Farewell to zygomatic implants and extensive augmentations?

BACKGROUND

Dental rehabilitation of severe atrophic upper jaws remains challenging. A new generation of subperiosteally placed and rigid multi-vector bone-anchored patient-specific implants proposes an innovative line extension in implant dentistry. This single-center retrospective study focused on treating severely atrophic maxillae using these implants.

METHODS

All patients who were treated with a patient-specific implant (IPS Implant® Preprosthetic, KLS-Martin, Tuttlingen, Germany) at Hannover Medical School due to severe atrophy of the maxilla who had no history of malignancy, cleft lip or palate, or trauma were evaluated regarding implant stability and prosthetic restoration, as well as complications.

RESULTS

Out of a total of 58 inserted implants, 13 implants in 10 patients, which were placed to treat a severely atrophic upper jaw, were identified. The mean follow-up period was 8.2 months (1-29 months). All implants were clinically stable over the entire period. All patients with an observation period of over 2 months received prosthetics for restoration. Minor complications, screw fractures, infection, and exposure of the framework were observed, but these did not lead to failure.

CONCLUSION

This initial follow-up suggests that this new generation of implants represents a valuable treatment alternative, especially for patients with a history of failed dental implant placement. Larger numbers of cases and longer observation periods are required to confirm our findings.

The role of cortical perforations in allogeneic block grafting for lateral augmentation in maxilla: A randomized clinical trial

BACKGROUND

The need of decortication on the recipient site remains unclear for bone regeneration. To our knowledge, there are no human clinical trials that studied the influence of decortication on cancellous allogeneic block grafting.

PURPOSE

The aim of the present study is to evaluate the influence of perforating the cortex of the recipient site on cancellous allogeneic block graft integration and revascularization in the maxilla.

MATERIAL AND METHODS

Twenty-six patients referred for lateral bone augmentation were included in this clinical trial. Patients received freeze-dried bone allograft cancellous blocks obtained from the iliac crest; cortical perforations of the recipient bed were performed in the test group while in the control group it was left intact. After a 4-month healing period another surgery was performed to place dental implants, and a bone biopsy was collected using a trephine. All samples underwent micro-CT scans, and were processed for histomorphometric and immunohistochemical analysis. Implant survival comparisons were made using a repeated measures analysis of variance (ANOVA) while all other variables were compared using the analysis of covariance (ANCOVA).

RESULTS

One hundred and nineteen implants were placed into 110 augmented sites. One hundred percent implant survival rate was reported during 24 months follow-up period. No differences were reported in bleeding on probing at 1 (5.6 vs 9%) and 2 years (13.2 vs 12.1%), probing pocket depth at 1 (3.4 ± 0.95 vs 3.6 ± 1.12 mm) and 2 years (3.8 ± 1.02 vs 4.1 ± 1.46 mm), and marginal bone loss at 1 (0.2 ± 0.52 vs 0.3 ± 0.57 mm) and 2 years (0.6 ± 0.91 vs 0.5 ± 0.87 mm). No statistically significant differences were found in the micro-CT and histomorphometric analysis in terms of newly formed bone (25.7 ± 11.2% vs 22.3 ± 9.7%), soft tissue (33.0 ± 14.7% vs 36.5 ± 15.7%), remnant allograft (39.3 ± 20.4% vs 41.2 ± 22.7%), and bone mineralization (57.2 ± 10.6% vs 53.8 ± 8.7%). Perforating the cortex of the recipient site had no significant effect on angiogenesis as shown by immunohistochemical analysis of CD34 positive blood vessels (39.21 ± 10.53/mm² vs 34.16 ± 12.67/mm² ).

CONCLUSION

Cancellous allogeneic bone block grafts are a clinically acceptable alternative for horizontal bone augmentation. Cortical perforations of the recipient site in the maxilla did not improve angiogenesis nor bone formation within the block graft.

Maxillary Sinus Floor Augmentation with Autogenous Bone Graft Compared with a Composite Grafting Material or Bone Substitute Alone: a Systematic Review and Meta-Analysis Assessing Volumetric Stability of the Grafting Material

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 and hand-search of relevant journals were conducted. Human studies published in English until the 9^th of October 2020 were included. Outcome measures included three-dimensional volumetric changes of the grafting material and potential predictive parameters. Volumetric changes were evaluated by descriptive statistics and meta-analysis including 95% confidence interval.

Results

Electronic search and hand-searching resulted in 102 entries. Four randomized controlled trials with unclear risk of bias fulfilled the inclusion criteria. The volumetric stability of the grafting material was significantly improved by mixing autogenous bone graft with a non-resorbable xenograft compared with autogenous bone graft. Meta-analyses assessing absolute and relative volumetric changes demonstrated no significant differences between autogenous bone graft compared with allogeneic bone graft, synthetic biomaterials combined with autogenous bone graft or used alone. Association between volumetric changes of the grafting material and potential predictive parameters were not assessed in the included studies.

Conclusions

Volumetric reduction of the augmented area seems inevitable following maxillary sinus floor augmentation regardless of the grafting material. The volumetric stability of autogenous bone graft is improved with addition of xenograft compared with autogenous bone graft. However, conclusions drawn from this systematic review should be interpreted with caution since only four studies using three-dimensional radiographic measurements were included.