Volumetric changes after sinus augmentation using blocks of autogenous iliac bone or freeze-dried allogeneic bone. A non-randomized study

Long-term effectiveness of UV functionalised short (≤ 6 mm) dental implants placed in the posterior segments of the atrophied maxilla: controlled case series

This study evaluated long-term effectiveness UV functionalised short implants (≤ 6 mm) placed in the posterior segments of the atrophied maxilla. The study included 47 patients from 2018 to 2023 (aged 27 to 56 years, 24 women and 23 men) without any systemic diseases, with unilateral/bilateral missing teeth and vertical atrophy of the posterior maxillary area. Total installed were 64 short UV-functionalized implants and 62 standard implants over 10 mm in length in segments maxilla with sufficient bone parameters. Clinical, laboratory and cone beam computed tomography (CBCT) methods were used to plan implant therapy. The clinical indices included the following parameters: ISQ, MBL, OHIP-G scale. For short implants, the median ISQ at placement was 62.2 for primary stability and the median ISQ at 5 months was 69.6 ISQ. For standard implant, the mean ISQ at placement was 64.3 ISQ, and ISQ after 5 months was 71.6 ISQ. After 6 months mean MBL short implants 0.87 mm, after 1 year 1.13 mm, after 5 years was 1.48 mm. After 6 months mean MBL standard implants 0.84 mm, after 1 year 1.24 mm, after 5 years was 1.58 mm. Mean OHIP-G scores-patients satisfaction with the implant at 4.8 ± 0.3, satisfaction with the operation 4.6 ± 0.4; satisfaction with prosthetics 4.7 ± 0.5. Cumulative success rate 5 years short implants was 96.7%, standard implants was 97.4%, and prosthesis cumulative survival rate was 97.2%. Short ultraviolet functionalized implants used in the posterior resorbed segment of maxilla have been shown to be a reliable alternative to sinus lift, demonstrating fewer complications, reduction in the number of additional surgical interventions and showed satisfactory long-term survival.

Biomechanical Investigation of the Osseointegration of Titanium Implants With Different Surfaces Placed With Allogeneic Bone Transfer

Allogeneic grafts can be preferred to autogenous grafts in plastic and oral-maxillofacial surgery for vertical and horizontal bone deficiencies. Implant surface properties are an important factor in osseointegration. This study aims to evaluate the osseointegration levels of titanium implants with machined, sand-blasted, and acid-etched (SLA) and resorbable blast material (RBM) surfaces placed together with allogeneic bone tissue transplantations obtained from the tibia bone using biomechanical method. Twenty-five female Sprague-Dawley rats were included in the study. The rats were divided into groups in which machined (n=7), SLA (n=7), and RBM (n=7) surface implants were placed with the transplantation of bone taken from the tibia. Four rats (both left and right tibias) were used as donors. Grafts and implants were surgically placed in the corticocancellous part of the metaphyseal area of the tibia bones of rats. At the end of the 4-week experimental setup, all rats were killed, and the implants and surrounding bone tissue were subjected to biomechanical reverse torque analysis (N/cm). Sand-blasted acid-etched surface implants were observed to have higher biomechanical osseointegration levels than RBM and machined surface implants (P<0.05). No statistical difference could be detected between the RBM and machined surface implants (P>0.05). On the basis of the limited results of this study, it can be concluded that the osseointegration levels of SLA surface implants placed with allogeneic bone transplantation may be better than those of machined and RBM surface implants.

The Use of Allograft Bone in the Lateral Approach of Sinus Floor Elevation: A Systematic Review of Clinical Studies

Background and Objectives: The aim of this systematic review was to assess the efficiency of using allografts for sinus lift. Materials and Methods: This systematic review was written under the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and recommendation of the Cochrane Handbook for Systematic Reviews of Interventions. Three electronic databases were screened until October 2023. The risk of bias was assessed according to the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) guidelines. Statistical analysis was performed for median bone volume and implant survival rate. Results: From 321 articles retrieved, 7 articles were included in this review. A comparison between freeze-dried bone allograft (FDBA) and deproteinized bovine bone (DBB) for mean bone volume indicated a weighted mean difference (WMD) of -0.17 [-0.69, 0.36] (95% confidence interval (CI)), p = 0.53. For implant survival rate, a comparison was made between FDBA and autogenous bone indicating a risk ratio (RR) of 1.00 [0.96, 1.05] (95% CI), p = 1.00. Conclusions: The available evidence suggested that allograft bone can be used in sinus lift procedures. The results obtained are insufficient to compare with other types of bone graft, requiring a longer follow-up time. Future clinical trials are needed in order to evaluate the advantages of using allograft bone.

Risk factors and longitudinal regenerative outcomes of sinus membrane perforation during lateral window sinus floor elevation: A retrospective analysis up to 9 years

BACKGROUND

Lateral-window sinus floor elevation (LSFE) is a reliable procedure to reconstruct the posterior maxilla for implant therapy. This retrospective study aimed to investigate risk factors associated with Schneiderian membrane perforation (SMP) occurrence during LSFE and longitudinal regenerative outcomes following LSFE up to 9 years.

METHODS

Patients who had LSFE between 2010 and 2019 were included. All demographic and surgical-related data were retrieved from existing electronic health records. Radiographs were used to evaluate the vertical dimensional changes of ridge and graft materials and the potential anatomic factors of SMP.

RESULTS

A total of 122 LSFE procedures in 99 patients were included in the study. Mean ridge height gain and graft shrinkages were 9.5 ± 3.47 and 1.57 ± 2.85 mm. The influence of the healing period on graft shrinkage showed a positive trend; the longer the healing period, the greater the graft shrinkage (p = 0.09). The pathology in the sinus showed a positive correlation with SMP (p = 0.07). However, other anatomical factors did not negatively impact SMP and subsequent ridge height gain (p > 0.05).

CONCLUSIONS

With inherent limitation, the findings with up to 9 years of follow-up indicate a consistent ridge remodeling lasting for about 3 years after LSFE procedures. SMP or membrane thickening may not significantly affect the ridge gain following LSFE. The healing period had the most significant influence on graft shrinkage, showing that the longer the healing time between LSFE and implant placement, the greater the graft shrinkage.

An Empirical Model Linking Physico-Chemical Biomaterial Characteristics to Intra-Oral Bone Formation

Facial trauma, bone resection due to cancer, periodontal diseases, and bone atrophy following tooth extraction often leads to alveolar bone defects that require bone regeneration in order to restore dental function. Guided bone regeneration using synthetic biomaterials has been suggested as an alternative approach to autologous bone grafts. The efficiency of bone substitute materials seems to be influenced by their physico-chemical characteristics; however, the debate is still ongoing on what constitutes optimal biomaterial characteristics. The purpose of this study was to develop an empirical model allowing the assessment of the bone regeneration potential of new biomaterials on the basis of their physico-chemical characteristics, potentially giving directions for the design of a new generation of dental biomaterials. A quantitative data set was built composed of physico-chemical characteristics of seven commercially available intra-oral bone biomaterials and their in vivo response. This empirical model allowed the identification of the construct parameters driving optimized bone formation. The presented model provides a better understanding of the influence of driving biomaterial properties in the bone healing process and can be used as a tool to design bone biomaterials with a more controlled and custom-made composition and structure, thereby facilitating and improving the clinical translation.

Slim the face or not: 3D change of facial soft and hard tissues after third molars extraction: a pilot study

BACKGROUND

Whether slim the face or not after removed third molars is the concern of some orthodontic treatment candidates. The aim of this article is to explore the volume changes of facial soft and hard tissues after third molars extraction, as well as develop a reproducible clinical protocol to precisely assess facial soft tissue volume change.

METHODS

A non-randomized, non-blind, self-controlled pilot study was conducted. 24 adults aged 18-30 had ipsilateral third molars extracted. The body weight change was controlled within 2 kg. Structured light scans were taken under a standardized procedure pre-extraction (T0), three (T1), and six (T2) months post-extraction; CBCTs were taken at T0 and T2. The projection method was proposed to measure the soft tissue volume (STV) and the soft tissue volume change (STVC) by the Geomagic software. The hard tissue volume change (HTVC) was measured in the Dragonfly software.

RESULTS

The final sample size is 23, including 5 males (age 26.6 ± 2.5 years) and 18 females (age 27.3 ± 2.5 years). The HTVC was - 2.33 ± 0.46ml on the extraction side. On the extraction side, the STV decreased by 1.396 (95% CI: 0.323-2.470) ml (P < 0.05) at T1, and increased by 1.753 (95% CI: -0.01-3.507) ml (P = 0.05) at T2. T2 and T0 had no difference (P > 0.05). The inter and intra-raters ICC of the projection method was 0.959 and 0.974. There was no correlation between the STVC and HTVC (P > 0.05).

CONCLUSIONS

After ipsilateral wisdom teeth extraction, the volume of hard tissue on the extraction side reduces, and the volume of facial soft tissue does not change evidently. However, further research with large sample size is still needed. The STV measurement has excellent repeatability. It can be extended to other interested areas, including forehead, nose, paranasal, upper lip, lower lip and chin, which is meaningful in the field of orthodontics and orthopedics.

TRIAL REGISTRATION

ChiCTR, ChiCTR1800018305 (11/09/2018), http://www.chictr.org.cn/showproj.aspx?proj=28868 .

Clinical and radiographic outcomes of dental implant after maxillary sinus floor augmentation with rhBMP-2/hydroxyapatite compared to deproteinized bovine bone

Objectives

This study aimed to evaluate the clinical and radiographic outcomes of early implant placement and functional loading in maxillary sinus floor augmentation (MSFA) using recombinant human bone morphogenetic protein 2/hydroxyapatite (rhBMP-2/HA) and to compare these outcomes with those of the conventional protocol in MSFA using deproteinized bovine bone (DBB).

Materials and methods

The rhBMP-2/HA and DBB groups consisted of 14 and 13 patients who underwent MSFA with BMP and DBB, respectively. After placement of 22 implants and 21 implants in the rhBMP-2/HA and DBB groups, respectively, abutment connections were performed 3 months after implant placement for the rhBMP-2/HA group and 6 months after implant placement for the DBB group. Changes in grafted sinus height (GSH), marginal bone loss (MBL), and implant stability were evaluated up to one year after functional loading.

Results

Survival rates for the rhBMP-2/HA and DBB groups after one year of functional loading were 90.9% and 90.5%, respectively. Both groups exhibited no significant time-course changes in GSH until one year of functional loading (rhBMP-2/HA, p = 0.124; DBB, p = 0.075). Although significant MBL occurred after one year of functional loading for both groups (rhBMP-2/HA, p < 0.001; DBB, p < 0.001), there were no significant differences in time-course changes in MBL between the two groups (p = 0.450). The mean implant stability quotient values in the rhBMP-2/HA and DBB groups were 75.3 and 75.4 after one year of functional loading, respectively, and there were no significant differences between the two groups (p = 0.557).

Conclusions

MSFA using rhBMP-2/HA allowed implant rehabilitation with early implant placement and functional loading and led to a comparable survival rate and implant stability after 1 year of functional loading with acceptable MBL and stable maintenance of GSH compared to the MSFA using DBB with 6 months of healing after implant placement.

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.

Comparison of Physicochemical, Mechanical, and (Micro-)Biological Properties of Sintered Scaffolds Based on Natural- and Synthetic Hydroxyapatite Supplemented with Selected Dopants

The specific combinations of materials and dopants presented in this work have not been previously described. The main goal of the presented work was to prepare and compare the different properties of newly developed composite materials manufactured by sintering. The synthetic- (SHAP) or natural- (NHAP) hydroxyapatite serves as a matrix and was doped with: (i) organic: multiwalled carbon nanotubes (MWCNT), fullerenes C60, (ii) inorganic: Cu nanowires. Research undertaken was aimed at seeking novel candidates for bone replacement biomaterials based on hydroxyapatite—the main inorganic component of bone, because bone reconstructive surgery is currently mostly carried out with the use of autografts; titanium or other non-hydroxyapatite -based materials. The physicomechanical properties of the developed biomaterials were tested by Scanning Electron Microscopy (SEM), Dielectric Spectroscopy (BSD), Nuclear Magnetic Resonance (NMR), and Differential Scanning Calorimetry (DSC), as well as microhardness using Vickers method. The results showed that despite obtaining porous sinters. The highest microhardness was achieved for composite materials based on NHAP. Based on NMR spectroscopy, residue organic substances could be observed in NHAP composites, probably due to the organic structures that make up the tooth. Microbiology investigations showed that the selected samples exhibit bacteriostatic properties against Gram-positive reference bacterial strain S. epidermidis (ATCC 12228); however, the property was much less pronounced against Gram-negative reference strain E. coli (ATCC 25922). Both NHAP and SHAP, as well as their doped derivates, displayed in good general compatibility, with the exception of Cu-nanowire doped derivates.

The Relation between Morphology of Maxillary Sinus after Augmentation in Three Classification Methods and Residual Bone Height: A Retrospective Study

Maxillary sinus augmentation is critical to oral implantology, particularly in some cases. The morphology of the sinus floor reflects the lifting effect to a certain extent; however, there has been limited research on the morphology after sinus augmentation. The present study aims to investigate the relationship between residual bone height (RBH) and the morphology of the sinus floor and determine whether a correlation exists between the different evaluation classifications. Maxillary sinus floor augmentation procedures were performed in 56 patients and 68 teeth using the sinus crest approach (SCA). Imaging results obtained after one year of sinus augmentation were analyzed and simultaneously classified along the coronal plane, the sagittal plane, and the biplane (coronal-sagittal). The higher the RBH, the closer the result tends to be to A, A', or type 1 (more satisfactory). There was a significant correlation between the three different evaluation classifications (p < 0.05). The morphology of perforation cases was involved in types C, D, C', and D'. A more satisfactory post-lifting morphology (tent type and flat type) is probably related to an optimal preoperative bone height, and an unsatisfactory post-lifting morphology is related to a low preoperative sinus floor height. The sagittal plane evaluation correlates with the coronal plane and biplane evaluation and is thus more recommended.

Retrospective analysis of time-related three-dimensional iliac bone graft resorption following sinus lift and vertical augmentation in the maxilla

The atrophic maxilla frequently requires bone grafting using an onlay graft (OG) or sinus lifting (SL) before implant rehabilitation. The resorption of bone grafts is influenced by the time until implantation, quality of donor bone, and grafting technique. The aim of this study was to investigate the impact of both grafting techniques on the time-related resorption of autologous iliac bone graft. Forty-three patients underwent either onlay grafting or a sinus lift at 73 sites in the maxilla. Graft height was measured by cone beam computed tomography after augmentation and during follow-up for up to 12 months prior to implant insertion. The effect of time and technique on graft resorption was evaluated retrospectively. The reduction in bone graft height was greater for OG than SL over the investigated time intervals (OG = 51%, SL = 28%; P = 0.002). Each technique followed a specific course of resorption, which was independent of the initial graft height and could be calculated by a non-linear regression model. Iliac bone graft undergoes rapid resorption when used as an OG prior to implant insertion. For SL, this resorption is reasonably lower. This is especially crucial to determine the optimal time for implant insertion after graft healing to improve implant survival.

Radiological changes in maxillary sinus morphology after lateral sinus floor augmentation

&lt;b&gt;Background:&lt;/b&gt; Restoration of the masticatory function in patients with edentulous posterior maxilla is often challenging due to the severe atrophy of the alveolar ridges and proximity of the maxillary sinus, resulting in insufficient bone quantity for implant-supported dentures. &lt;br&gt;&lt;b&gt;Aim:&lt;/b&gt; The purpose of this study was to analyze the changes in Schneiderian membrane thickness after lateral sinus floor augmentation (LSFA) using cone beam computed tomography (CBCT). &lt;br&gt;&lt;b&gt;Material and methods:&lt;/b&gt; WLSFA procedures using different bone grafting materials were performed in 87 patients, operated on in two clinical institutions from 2016 to 2018. CBCT examination was performed in all patients before the LSFA procedure, at 1 month after surgery, and after 6 months, before implant placement or loading. &lt;br&gt;&lt;b&gt;Results: &lt;/b&gt;Minor r adiological changes in mucous membrane morphology were observed preoperatively in 17.1% of patients. Postoperative CBCT in the early postsurgical period demonstrated that the number of intact non-specific sinuses decreased significantly, i.e. from 86.7% to 26.7%. The number of cases with local hypertrophia of the mucous membrane increased from 20.3% to 26.7%. Mucosal thickening was observed in 41.7% vs 7.5%. The number of intact sinuses increased to 57.8%. The number of cases with local membrane hypertrophia also increased - to 37.4%. The number of cases with mucosal thickening or fluid accumulation decreased significantly to 11.8 and 5.3% respectively. In 2 cases the development of chronic sinusitis required secondary surgeries. &lt;br&gt;&lt;b&gt;Conclusion:&lt;/b&gt; The present retrospective study revealed that minor radiological changes in the morphology of the maxillary sinus mucosa were observed preoperatively in 17.1% of patients who underwent LSFA procedures. In the early and late postoperative period their frequency increased to 68.5% and 47.1%, respectively. However, the clinical signs of sinusitis developed only in 19.26% of patients. No significant correlations were found between the frequency and severity of postoperative radiological changes and residual bone height, sinus anatomy, initial state of the mucous membrane and type of the grafting material.

Bone Graft Materials for Alveolar Bone Defects in Orthodontic Tooth Movement

Clinically, orthodontic tooth movement (OTM) across the narrow alveolar ridge area inevitably entails some adverse reactions such as limited movement and periodontal tissue damage. Hence, it is essential to reconstruct the morphology of the alveolar crest before the tooth movement. Unlike the routine reconstruction of alveolar ridge in the field of implant, the orthodontic practices are distinctive, which require dental movement across the constructed alveolar ridge with safety and stability. Herein, we addressed the pros and cons of reconstruction of the defected orthodontic alveolar ridge with different bone graft materials. Attention is also paid to other factors such as the postgraft initiation time of OTM that can substantially influence the bone reconstruction and tooth movement effect. Rather, considering the lack of a unified standard in orthodontic clinics related to bone reconstruction for OTM, we provide some recommendations and guidance for OTM through alveolar ridge defect area.

Radiological changes in maxillary sinus morphology after lateral sinus floor augmentation

<b>Background:</b> Restoration of the masticatory function in patients with edentulous posterior maxilla is often challenging due to the severe atrophy of the alveolar ridges and proximity of the maxillary sinus, resulting in insufficient bone quantity for implant-supported dentures. <br><b>Aim:</b> The purpose of this study was to analyze the changes in Schneiderian membrane thickness after lateral sinus floor augmentation (LSFA) using cone beam computed tomography (CBCT). <br><b>Material and methods:</b> W LSFA procedures using different bone grafting materials were performed in 87 patients, operated on in two clinical institutions from 2016 to 2018. CBCT examination was performed in all patients before the LSFA procedure, at 1 month after surgery, and after 6 months, before implant placement or loading. <br><b>Results:</b> Minor r adiological changes in mucous membrane morphology were observed preoperatively in 17.1% of patients. Postoperative CBCT in the early postsurgical period demonstrated that the number of intact non-specific sinuses decreased significantly, i.e. from 86.7% to 26.7%. The number of cases with local hypertrophia of the mucous membrane increased from 20.3% to 26.7%. Mucosal thickening was observed in 41.7% vs 7.5%. The number of intact sinuses increased to 57.8%. The number of cases with local membrane hypertrophia also increased – to 37.4%. The number of cases with mucosal thickening or fluid accumulation decreased significantly to 11.8 and 5.3% respectively. In 2 cases the development of chronic sinusitis required secondary surgeries. <br><b>Conclusion:</b> The present retrospective study revealed that minor radiological changes in the morphology of the maxillary sinus mucosa were observed preoperatively in 17.1% of patients who underwent LSFA procedures. In the early and late postoperative period their frequency increased to 68.5% and 47.1%, r espectively. However, the clinical signs o f sinusitis developed only in 19.26% of patients. No significant correlations were found between the frequency and severity of postoperative radiological changes and residual bone height, sinus anatomy, initial state of the mucous membrane and type of the grafting material.

Ibandronate Reduces the Surface Bone Resorption of Mandibular Bone Grafts: A Randomized Trial With Internal Controls

Autologous bone grafts are considered the gold standard for reconstruction of the edentulous alveolar ridges. However, this procedure is associated with unpredictable bone loss caused by physiological bone resorption. Bisphosphonates are antiresorptive drugs that act specifically on osteoclasts, thereby maintaining bone density, volume, and strength. It was hypothesized that the resorption of bone grafts treated with an ibandronate solution would be less advanced than bone grafts treated with saline. Ten patients who underwent bilateral sagittal split osteotomy were included in a randomized double‐blind trial with internal controls. Each patient received a bone graft treated with a solution of ibandronate on one side and a graft treated with saline (controls) contralaterally. Radiographs for the measurement of bone volume were obtained at 2 weeks and at 6 months after surgery. The primary endpoint was the difference in the change of bone volume between the control and the ibandronate bone grafts 6 months after surgery. All of the bone grafts healed without complications. One patient was excluded because of reoperation. In eight of the nine patients, the ibandronate bone grafts showed an increase in bone volume compared with baseline, with an average gain of 126 mm³ (40% more than baseline) with a range of +27 to +218 mm³. Only one ibandronate‐treated graft had a decrease in bone volume (8%). In the controls, an average bone volume loss of −146 mm³ (58% of baseline) with a range of −29 to −301 mm³ was seen. In the maxillofacial field, the reconstructions of atrophic alveolar ridges, especially in the esthetical zones, are challenging. These results show that bone grafts locally treated with ibandronate solution increases the remaining bone volume. This might lead to new possibilities for the maxillofacial surgeons in the preservation of bone graft volumes and for dental implant installations. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Alveolar ridge augmentation using the shell technique with allogeneic and autogenous bone plates in a split-mouth design-A retrospective case report from five patients

Atrophic alveolar ridges of five patients were augmented with allografts and autografts on opposite sites, followed by dental implantation. Both augmentation materials led to equivalent bone gains. Allografts did not compromise the clinical outcome.

Sinus augmentation - autograft vs. fresh frozen allograft: Bone density dynamics and implant stability

OBJECTIVES

Compare bone density changes and initial implant stability following sinus augmentation with autogenous bone (AB) vs. fresh frozen bone (FFB).

MATERIALS AND METHODS

Randomized, prospective, split mouth study. Sinus augmentation executed using either AB or FFB. Dental implants were inserted after 6 months of healing. Implant dimensions and insertion torques were recorded. Prostheses were delivered 6 months thereafter. All patients had computerized tomography (CT) scans 1 week (T1) and 6 months (T2) after initial bone grafting. Third CT (T3) was taken 12 months after prosthesis delivery. Data from CT scans was used to analyze bone density at each period.

RESULTS

A total of 15 patients (8 males, 7 females) following bilateral sinus augmentation procedures, were included. Mean age was 54 ± 5 years (range 48-60 years). All patients had 3 CT examinations. The initial augmented AB density was higher than the initial FFB density. Nevertheless, density differences between the two groups were not statistically significant at any time frame. At T2 density of both grafts showed a statistically significant increase. A significant increase from T2 to T3 was noted only for the FFB group. Implant insertion torque was significantly higher in the FFB group. Insertion torque ≥32 N/cm was achieved in significantly more patients in the FFB group.

CONCLUSION

The use of FFB for sinus augmentation is a reliable option of graft material. The newly formed bone quality performance, evaluated by CBCT density, is as good as AB, allowing predictable initial implant stability and osseointegration. Unnecessary morbidity associated with AB harvesting is thus avoided.

Patient-specific implants for maxillofacial defects: challenges and solutions

Background

Reconstructing maxillofacial defects is quite challenging for most surgeons due to the region’s complex anatomy and cosmetic and functional effects on patients. The use of pre-made alloplastic implants and autogenous grafts is often associated with resorption, infection, and displacement. Recent technological advances have led to the use of custom computer-designed patient-specific implants (PSIs) in reconstructive surgery. This study describes our experience with PSI, details the complications we faced, how to overcome them, and finally, evaluates patient satisfaction.

Case presentation

Six patients underwent reconstruction of various maxillofacial defects arising due to different etiologies using PSI. A combined total of 10 implants was used. PEEK was used to fabricate 8, while titanium was used to fabricate 2. No complications were seen in any patient both immediately post-op and in subsequent follow-ups. All patients reported a high level of satisfaction with the final result both functionally and cosmetically.

Conclusion

The use of computer-designed PSI enables a more accurate reconstruction of maxillofacial defects, eliminating the usual complications seen in preformed implants and resulting in higher patient satisfaction. Its main drawback is its high cost.

Volume stability of the augmented sinus using a collagenated bovine bone mineral grafted in case of a perforated Schneiderian membrane: An experimental study in rabbits

OBJECTIVES

To determine the volume stability of a sinus augmented with a collagenated bovine bone mineral (CBBM) in case of an intact or perforated Schneiderian membrane (SM).

MATERIALS AND METHODS

A bilateral sinus augmentation procedure was performed in eight rabbits. The SM was intentionally perforated in one side (SMP group), while it remained intact in contra-lateral side (control group) and the same amount of CBBM was then grafted. At 12 weeks, the animals were euthanized for radiographic and histomorphometric analyses.

RESULTS

The augmented volume did not differ significantly between the two groups: 262.2 ± 32.1 mm³ in SMP group and 261.9 ± 48.5 mm³ in the control group (p = .959). There was no significant difference in the total augmented area: 24.7 ± 5.2 mm² in SMP group and 23.2 ± 2.9 mm² in the control group (p = .773). The areas of newly formed bone also did not differ significantly between the two groups, but was significantly lower at the centre of the augmented region than in the region of the surgical window in both groups (p < .05).

CONCLUSION

A perforation of the SM in a rabbit model does neither impact the augmented volume nor new bone formation following grafting of the sinus with a CBBM.

Automatic three-dimensional analysis of bone volume and quality change after maxillary sinus augmentation

INTRODUCTION

Maxillary sinus augmentation is a widely used surgical procedure to increase the bone volume before implant placement. In order to predict the stability of the implant, analysis of the change in bone volume and quality after a sinus graft procedure is necessary. The purpose of this study was to analyze the change in volume and quality of bone graft material after maxillary sinus augmentation using cone beam computed tomography (CBCT).

METHODS AND MATERIALS

Maxillary sinus lift procedures using bovine bone materials (Bio-Oss, Geistrich, Swiss) without immediate implantation were performed at the Pusan National University Dental Hospital in 22 patients, from 2014 to 2017. CBCT images were captured before surgery (T1), a day after surgery (T2), and after 4 to 7 months at follow-up (T3). The T2 and T3 images were registered to the T1 image using histogram matching and intensity-based registration. A total of 30 sinuses were analyzed three-dimensionally (3-D), using self-made software MATLAB 2018a (MathWorks, Natick, Massachusetts). The volume and structural indices of the bone graft material were measured and analyzed.

RESULTS

The average volume of graft material showed a decrease, while the average gray value showed an increase during the follow-up period, but these changes were not statistically significant. The structural indices of the graft material after histogram matching showed a significant difference in homogeneity, connectivity, thickness, and roughness at the postoperative follow-up.

CONCLUSIONS

The volume and gray value showed no statistically significant changes after the maxillary sinus lift procedures. The results of this study show that structural analysis using histogram matching can be used as a promising tool to analyze the quality of graft materials.

Effect of GARP on osteogenic differentiation of bone marrow mesenchymal stem cells via the regulation of TGFβ1 in vitro

Mesenchymal stem cells (MSCs), which have multipotential differentiation and self-renewal potential, are possible cells for tissue engineering. Transforming growth factor β1 (TGFβ1) can be produced by MSCs in an inactive form, and the activation of TGFβ1 functions as an important regulator of osteogenic differentiation in MSCs. Recently, studies showed that Glycoprotein A repetitions predominant (GARP) participated in the activation of latent TGFβ1, but the interaction between GARP and TGFβ1 is still undefined. In our study, we successfully isolated the MSCs from bone marrow of rats, and showed that GARP was detected in bone mesenchymal stem cells (BMSCs). During the osteogenic differentiation of BMSCs, GARP expression was increased over time. To elucidate the interaction between GARP and TGFβ1, we downregulated GARP expression in BMSCs to examine the level of active TGFβ1. We then verified that the downregulation of GARP decreased the secretion of active TGFβ1. Furthermore, osteogenic differentiation experiments, alkaline phosphatase (ALP) activity analyses and Alizarin Red S staining experiments were performed to evaluate the osteogenic capacity. After the downregulation of GARP, ALP activity and Alizarin Red S staining significantly declined and the osteogenic indicators, ALP, Runx2, and OPN, also decreased, both at the mRNA and protein levels. These results demonstrated that downregulated GARP expression resulted in the reduction of TGFβ1 and the attenuation of osteoblast differentiation of BMSCs in vitro.

Comparison of Pixel Values of Maxillary Sinus Grafts and Adjacent Native Bone With Cone-Beam Computed Tomography

PURPOSE

Pixel values from cone-beam computed tomography (CBCT) are proportional to bone density. This study aimed to correlate and compare pixel values of healed maxillary sinus grafts and adjacent native bone (NB).

MATERIAL AND METHODS

This study was conducted on CBCT scan patients referred for maxillary sinus floor augmentation with biphasic calcium phosphate (n = 31). Graft height and width measurements were performed. In addition, mean pixel values were calculated in 3 different regions: NB, sinus graft close to NB (CNB), and sinus graft far from NB (FNB). Micro-CT and histological analyses of bone specimens of a representative case were also performed.

RESULTS

Significant correlations were found between CNB and graft height (r = 0.41; P < 0.021); and FNB and graft width (r = 0.519, P < 0.003). In addition, pixel values from both graft groups (CNB and FNB) differed significantly (P < 0.001). Finally, histological sections revealed smaller areas with newly formed bone in the FNB area.

CONCLUSIONS

Within the limitations of this study, the present findings suggest that pixel values of sinus grafted areas are directly correlated with the extension of the grafted area.

A Step-by-Step Procedure for Bone Regeneration Using Calcium Phosphate Scaffolds: From Site Preparation to Graft Placement

Hydroxyapatite (HA) is the main mineral component of bone and teeth. HA is often used as a bone substitute and especially in its granular form it is osteoconductive and osseointegrating as shown by many investigations in animals and humans. HA granules are used for filling bone defects, but they have poor handling qualities and retention at the surgical site, leading to graft voids between the granules and bone tissue and resulting in mechanical instability. Furthermore HA implantation is not constantly followed by favorable results, especially when it is carried out for augmentation of the alveolar ridge. This article offers a protocol for bone reconstruction and predictable implant treatment outcomes. We provide a step-by-step description of both the recipient site and composite graft preparations using coralline HA granules (CHAG) and homologous fibrin glue (HFG). In the present study, 20 randomly selected patients (12 women and 8 men) underwent bone regeneration using CHAG-HFG before a dental implant procedure. Radiographic imaging, physical examination, and histological analysis were performed during a 2-year period. Biopsies were obtained at second-stage surgery before implant insertion using a 2.8-mm trephine bur. A morphological study of 20 bioptic human specimens was performed. Our results demonstrate that this surgical protocol for the preparation of the recipient site associated with a mixture of coralline HA granules with homologous fibrin glue provides reliable bone regeneration, thus reducing failures and minimizing risks of postoperative morbidity.

A 2-year prospective case series on volumetric changes, PROMs, and clinical outcomes following sinus floor elevation using deproteinized bovine bone mineral as filling material

BACKGROUND

A sinus floor augmentation may be indicated when a lack of hard tissue impedes implant placement. Although clinically successful, evidence supporting the long-term three-dimensional stability of the grafted volume is scarce. Second, evidence on the patient's acceptance of this type of treatment is limited.

PURPOSE

First is to evaluate the changes in graft volume after lateral wall sinus lifting based on superimposed cone beam computed tomography (CBCT) images and then to assess patient-reported outcome measures (PROMs) and clinical outcomes.

MATERIALS AND METHODS

Partially edentulous patients in need of a sinus lift and fixed reconstruction on at least two neighboring implants were selected for a prospective case series. Lateral wall sinus augmentation was performed using deproteinized bovine bone mineral (DBBM) as the only filling material. Volumetric changes were quantified on the basis of a preoperative CBCT and three postoperative CBCTs (at 2 weeks, 3 months, and 2 years). PROMs and clinical parameters were registered.

RESULTS

Twenty-two patients (7 males, 15 females; mean age 59 years) participated of which three patients dropped out during the follow up. Graft volumes amounted to 1418.26 mm³ at 2 weeks, 1201.21 mm³ at 3 months, and 1130.13 mm³ at 2 years postoperative pointing to a relative graft volume stability of 79.7%. Swelling was the leading symptom during the first week. A peak in visual analogue scale scores was observed for pain, swelling, and hematoma the day of surgery and 1 day postoperation with a statistically significant decline between days 3 and 7. Hemorrhage and nose bleeding occurred in 18.2% and 27.3% of the subjects, respectively. About 95.5% of the subjects would undergo the treatment again. All implants integrated successfully and demonstrated healthy clinical conditions.

CONCLUSION

Lateral wall sinus augmentation using DBBM as the only filling material is a viable treatment concept given limited graft resorption, good patients' tolerance, and clinical outcomes.

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.

Facial Bone Reconstruction Using both Marine or Non-Marine Bone Substitutes: Evaluation of Current Outcomes in a Systematic Literature Review

The aim of the present investigation was to systematically analyse the literature on the facial bone reconstruction defect using marine collagen or not and to evaluate a predictable treatment for their clinical management. The revision has been performed by searched MEDLINE and EMBASE databases from 2007 to 2017. Clinical trials and animal in vitro studies that had reported the application of bone substitutes or not for bone reconstruction defect and using marine collagen or other bone substitute material were recorded following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The first selection involved 1201 citations. After screening and evaluation of suitability, 39 articles were added at the revision process. Numerous discrepancies among the papers about bone defects morphology, surgical protocols, and selection of biomaterials were found. All selected manuscripts considered the final clinical success after the facial bone reconstruction applying bone substitutes. However, the scientific evidence regarding the vantage of the appliance of a biomaterial versus autologous bone still remains debated. Marine collagen seems to favor the dimensional stability of the graft and it could be an excellent carrier for growth factors.

A description of the sequence of long-term behavior of autogenous boneblock in maxillary sinus augmentation in sheep: Additional morphologic and histomorphometric evidence

OBJECTIVE

To document the behavior of autogenous bone block in sinus lift and surgical consequences.

STUDY DESIGN

Twelve sinus lifts with autogenous hip bone blocks and simultaneous insertion of two implants in 6 adult female sheep. Polychrome sequential labelling and histologic and histomorphometric evaluation after 6, 16, and 26 weeks.

RESULTS

Augmentation material in the apical third was almost fully resorbed after 26 weeks (P = .00388). Percentage of bone tissue increased 0.5-1.0 mm from the implant in crestal region (15.3 ± 7.5% to 16.2 ± 10.1%), whereas it vanished in the apical region from 16 to 26 weeks (4.2 ± 10.4% to 0%) (P = .363).

CONCLUSIONS

Autogenous bone block leaves an apical thin but functionally crucial layer covering implants in a form follows function way. Denial of animal-originated biomaterials and prion diseases remain a rarely discussed issue. The use of an implant length-adapted autogenous transplant with osseoinductive advantages should be taken into consideration.

Autogenous bone grafts in oral implantology-is it still a "gold standard"? A consecutive review of 279 patients with 456 clinical procedures

Background

This study assessed the clinical outcomes of graft success rate and early implant survival rate after preprosthetic alveolar ridge reconstruction with autologous bone grafts.

Methods

A consecutive retrospective study was conducted on all patients who were treated at the military outpatient clinic of the Department of Oral and Plastic Maxillofacial Surgery at the military hospital in Ulm (Germany) in the years of 2009 until 2011 with autologous bone transplantation prior to secondary implant insertion. Intraoral donor sites (crista zygomatico-alveolaris, ramus mandible, symphysis mandible, and anterior sinus wall) and extraoral donor site (iliac crest) were used. A total of 279 patients underwent after a healing period of 3–5 months routinely computer tomography scans followed by virtual implant planning. The implants were inserted using guided oral implantation as described by Naziri et al. All records of all the consecutive patients were reviewed according to patient age, history of periodontitis, smoking status, jaw area and dental situation, augmentation method, intra- and postoperative surgical complications, and surgeon’s qualifications. Evaluated was the augmentation surgical outcome regarding bone graft loss and early implant loss postoperatively at the time of prosthodontic restauration as well a follow-up period of 2 years after loading.

Results

A total of 279 patients underwent 456 autologous augmentation procedures in 546 edentulous areas. One hundred thirteen crista zygomatico-alveolaris grafts, 104 ramus mandible grafts, 11 symphysis grafts, 116 grafts from the anterior superior iliac crest, and 112 sinus lift augmentations with bone scrapes from the anterior facial wall had been performed. There was no drop out or loss of follow-up of any case that had been treated in our clinical center in this 3-year period. Four hundred thirty-six (95.6%) of the bone grafts healed successfully, and 20 grafts (4.4%) in 20 patients had been lost. Fourteen out of 20 patients with total graft failure were secondarily re-augmented, and six patients wished no further harvesting procedure. In the six patients, a partial graft resorption was detected at the time of implantation and additional simultaneous augmentation during implant insertion was necessary. No long-term nerve injury occurred. Five hundred twenty-five out of 546 initially planned implants in 259 patients could be inserted into successfully augmented areas, whereas 21 implants in 20 patients due to graft loss could not be inserted. A final rehabilitation as preplanned with dental implants was possible in 273 of the 279 patients. The early implant failure rate was 0.38% concerning two out of the 525 inserted implants which had to be removed before the prosthodontic restoration. Two implants after iliac crest augmentation were lost within a period of 2 years after loading, concerning a total implant survival rate after 2 years of occlusal loading rate of 99.6% after autologous bone augmentation prior to implant insertion.

Conclusions

This review demonstrates the predictability of autologous bone material in alveolar ridge reconstructions prior to implant insertion, independent from donor and recipient site including even autologous bone chips for sinus elevation. Due to the low harvesting morbidity of autologous bone grafts, the clinical results of our study indicate that autologous bone grafts still remain the “gold standard” in alveolar ridge augmentation prior to oral implantation.

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.

Influence of Sinus Floor Configuration on Grafted Bone Remodeling After Osteotome Sinus Floor Elevation

BACKGROUND

This study investigates influence of the sinus floor configuration on dimensional stability of grafted bone height after the osteotome sinus grafting procedure.

METHODS

Forty single-tooth dental implants inserted after placement of bioglass and/or allograft into the sinus area using an osteotome technique in 37 patients were evaluated in this retrospective study. Periapical radiographs were taken using the long-cone technique before and after implant placement. Specifically, radiographic measurements of grafted bone height at the mesial and distal side of each implant were taken, and the sinus floor configuration was classified into concave, angle, and flat according to the sinus floor profile at the implant site. Furthermore, the intruding angle, defined as the angle between the implant axis and sinus floor, was measured.

RESULTS

All implants were clinically stable during a mean follow-up period of 39.2 months. Mean initial gain of sinus grafted bone height was 7.0 ± 1.9 mm, and later it was reduced to 4.6 ± 1.9 mm at follow-up (P <0.001). A greater reduction in grafted bone height was revealed in the flat sinus group compared with the concave group (P <0.001). Results from the linear regression showed larger intruding angles were statistically significantly associated with a greater reduction in grafted bone height (r² = 0.55, P <0.001).

CONCLUSION

All bioglass and/or allograft placed in the maxillary sinus after the osteotome technique underwent remodeling and shrinkage; however, the outcome of the procedure was more predictable in sinuses with a concave floor and small implant-intruding angles.

Marginal and apical bone stability after staged sinus floor augmentation using bone condensing implants with variable-thread design: a two-dimensional analysis

Studies on the vertical stability of augmented bone after sinus lifting differ substantially. In addition, long healing periods are usually advocated prior to implant installation. The purpose of this case series study was to evaluate the changes in bone height after sinus lifting with a bovine-derived xenograft and to evaluate the clinical outcome of bone condensing implants installed after a short healing period. Patients treated during the years 2010-2013 were re-examined using peri-apical radiographs to evaluate the changes in augmented bone height (BH) and marginal bone loss (BL). Fifty-seven of 70 eligible subjects (28 male and 29 female, mean age 56 years) attended for reassessment. Data were available for 53 sinus lifts and 105 implants installed after a mean healing period of 4.6±1.5 months. Implant survival was 99% after a mean time in function of 19±9 months. Baseline BH, BH at implant placement, and final BH were on average 3.87±1.74mm, 13.75±2.12mm, and 13.11±2.12mm, respectively (P<0.001). Mean BL was 0.51±0.65mm. Only limited resorption is to be expected after sinus lifting in the short term. A bone condensing implant can be used in the early healing phase with successful outcomes in terms of implant survival and bone adaptation.

Maxillary sinus grafting with fresh frozen allograft versus bovine bone mineral: A tomographic and histological study

We evaluated histologically and tomographically the effects of fresh frozen bone allograft (FFB) or bovine bone mineral (BBM) in maxillary sinus floor augmentations. In total, 30 maxillary sinuses from 30 patients (mean age = 51.17 ± 10.86 years) underwent sinus augmentation. Patients were divided in two test groups (15 sinuses each). The first group was grafted with allograft bone, and the second group received bovine bone mineral. After 6 months, bone samples from each group were collected for histological examination. Implant survival rates were 97.78% (FFB group) and 100% (BBM group) 6 months after functional loading. Median volumetric reductions of 31.2% (11.33-40.56) and 12.22% (9.91-20.59) were observed in the FFB and BBM groups, respectively. Comparisons between the groups for differences in initial and final volumes of bone (p = 0.015) and the rate of resorption (p = 0.009) showed statistically significant differences. The FFB group showed osteoblastic cells in close contact with osteoid matrix, connected through bridges between allograft bone particles and new bone formation. The BBM group showed BBM particles in close contact with new bone, with visible osteoid matrix bridges and osteoblastic cells surrounding it. None showed signs of acute or chronic inflammatory infiltrate. Despite better results with BBM, both FFB and BBM in maxillary sinus augmentation resulted in high percentages of new bone formation, and allowed implant placement with a low rate of failure of osseointegration at a 6-month follow-up.

Mesenchymal stem cells in maxillary sinus augmentation: A systematic review with meta-analysis

AIM: To investigate the effectiveness of mesenchymal stem cells (MSCs) in maxillary sinus augmentation (MSA), with various scaffold materials.

METHODS: MEDLINE, EMBASE and SCOPUS were searched using keywords such as sinus graft, MSA, maxillary sinus lift, sinus floor elevation, MSC and cell-based, in different combinations. The searches included full text articles written in English, published over a 10-year period (2004-2014). Inclusion criteria were clinical/radiographic and histologic/ histomorphometric studies in humans and animals, on the use of MSCs in MSA. Meta-analysis was performed only for experimental studies (randomized controlled trials and controlled trials) involving MSA, with an outcome measurement of histologic evaluation with histomorphometric analysis reported. Mean and standard deviation values of newly formed bone from each study were used, and weighted mean values were assessed to account for the difference in the number of subjects among the different studies. To compare the results between the test and the control groups, the differences of regenerated bone in mean and 95% confidence intervals were calculated.

RESULTS: Thirty-nine studies (18 animal studies and 21 human studies) published over a 10-year period (between 2004 and 2014) were considered to be eligible for inclusion in the present literature review. These studies demonstrated considerable variation with respect to study type, study design, follow-up, and results. Meta-analysis was performed on 9 studies (7 animal studies and 2 human studies). The weighted mean difference estimate from a random-effect model was 9.5% (95%CI: 3.6%-15.4%), suggesting a positive effect of stem cells on bone regeneration. Heterogeneity was measured by the I² index. The formal test confirmed the presence of substantial heterogeneity (I² = 83%, P < 0.0001). In attempt to explain the substantial heterogeneity observed, we considered a meta-regression model with publication year, support type (animal vs humans) and follow-up length (8 or 12 wk) as covariates. After adding publication year, support type and follow-up length to the meta-regression model, heterogeneity was no longer significant (I² = 33%, P = 0.25).

CONCLUSION: Several studies have demonstrated the potential for cell-based approaches in MSA; further clinical trials are needed to confirm these results.

Radiographic Evaluation of Crestal Bone Loss Around Dental Implants in Maxilla and Mandible: One Year Prospective Clinical Study

PURPOSE

The aim of the study was to analyze the amount of maxillary and mandibular crestal bone loss around Bredent Sky Blue type of implants of different dimensions one year after implantation.

MATERIALS AND METHODS

36 implants of diameter 3.5 x 10 mm were inserted in the maxilla and 12 in the mandible. 52 implants of diameter 4.0 x 8 mm were inserted in the maxilla, and 61 in the mandible (two-stage implant surgery).

RESULTS

No statistically significant differences were found between the right and left side of the maxilla and between the right and left side of the mandible at the implant sites regarding distal and mesial bone losses as shown by analysis of variance (ANOVA).

CONCLUSION

Statistically significant differences were found between anterior maxilla, posterior maxilla and anterior mandible and posterior mandible at implant sites regarding distal and mesial bone losses as shown by analysis of variance (ANOVA).

A retrospective analysis of the relationship between rhinosinusitis and sinus lift dental implantation

INTRODUCTION

Dental implants have been associated with the occurrence of postoperative rhinosinusitis. In some patients, preoperative sinus lifting must be performed to increase the chances of successful implant placement. This retrospective study examines the relationship of dental implants after sinus lifting with the occurrence of postoperative rhinosinusitis.

METHODS

A total of 268 dental implants were inserted in 94 patients (62 Males, 32 Females) between 2011-2013. The ages ranged from 29-71 (in males) and 33-64 (in females). Additionally, bilateral sinus lifing was performed in 51 patients, and unilateral sinus lifting was performed in 43 of the patients. Patients were evaluated for sinus pathology for a period of 5-47 months postoperatively using a satisfaction questionnaire, conventional radiographic examination, and nasal endoscopic examination.

RESULTS

Four of the patients (4.2%) had a complication of postoperative sinusitis and were treated medically. In one patient, the implant was unsuccessful (even after treatment) and was removed. None of the patients needed surgery due to the sinusitis or any associated complications.

CONCLUSION

The risk for postoperative rhinosinusitis was found to be higher in patients who suffer from chronic sinusitis and in cases in which a large amount of graft was utilized for sinus lifting. These predisposing factors need to be considered when evaluating patients for dental implants and sinus lift procedures.

Synthetic biodegradable hydrogel delivery of demineralized bone matrix for bone augmentation in a rat model

There exists a strong clinical need for a more capable and robust method to achieve bone augmentation, and a system with fine-tuned delivery of demineralized bone matrix (DBM) has the potential to meet that need. As such, the objective of the present study was to investigate a synthetic biodegradable hydrogel for the delivery of DBM for bone augmentation in a rat model. Oligo(poly(ethylene glycol) fumarate) (OPF) constructs were designed and fabricated by varying the content of rat-derived DBM particles (either 1:3, 1:1 or 3:1 DBM:OPF weight ratio on a dry basis) and using two DBM particle size ranges (50-150 or 150-250 μm). The physical properties of the constructs and the bioactivity of the DBM were evaluated. Selected formulations (1:1 and 3:1 with 50-150 μm DBM) were evaluated in vivo compared to an empty control to investigate the effect of DBM dose and construct properties on bone augmentation. Overall, 3:1 constructs with higher DBM content achieved the greatest volume of bone augmentation, exceeding 1:1 constructs and empty implants by 3- and 5-fold, respectively. As such, we have established that a synthetic, biodegradable hydrogel can function as a carrier for DBM, and that the volume of bone augmentation achieved by the constructs correlates directly to the DBM dose.

Fresh-frozen allografts combined with bovine bone mineral enhance bone formation in sinus augmentation

We evaluated histologically, histomorphometrically, and tomographically the effects of the association of fresh-frozen bone allograft (FFB) with bovine bone mineral (BBM) in maxillary sinus floor augmentation. In total, 34 maxillary sinuses from 29 patients, with a mean age of 51.32 (±6.44) years, underwent sinus augmentation. Patients were divided into control and test groups (17 sinuses each). The controls were grafted with allograft bone, and the test group received a combination of FFB and BBM at a 2:1 ratio. After 6 months, bone samples were collected for histological and histomorphometric examinations. The implant survival rates were 93.02% (control group) and 100% (test group) at 6 months after functional loading. Median volumetric reductions of 28.32% (17.05-44.05) and 12.62% (5.65-16.87) were observed for the control and test groups, respectively. Statistically significant histomorphometric differences were found between the control and test groups regarding newly formed bone 12.54% (10.50-13.33) vs. 24.42% (17.62-35.92), p < 0.001, total bone 48.34% (39.03-54.42) vs. 61.32% (50.61-64.96), p = 0.007, and connective tissue 51.66% (45.57-60.97) vs. 39.30% (35.03-49.37), p = 0.007. The addition of BBM to allograft bone in maxillary sinus augmentation resulted in higher percentages of new bone formation and total bone, and permitted implant placement with a low rate of osseointegration failure at the 6-month follow-up.

A clinical and radiographic case series of implants placed with the simplified minimally invasive antral membrane elevation technique in the posterior maxilla

The aim of the present case series was to evaluate a simplified minimally invasive transalveolar sinus elevation technique utilizing calcium phosphosilicate (CPS) putty for hydraulic sinus membrane elevation. The simplified minimally invasive antral membrane elevation technique is based on the application of hydraulic pressure via a viscous bone graft that acts as an incompressible fluid. In this retrospective study, 21 patients (mean age: 48.5 ± 12 years) consecutively treated with the simplified minimally invasive transalveolar sinus elevation technique were evaluated. 28 tapered implants were placed in posterior maxillary sites with less than 6 mm of residual bone height as determined radiographically on cone beam volumetric tomographs. No sinus membrane perforations were noted and none of the patients complained of symptoms of sinusitis post-operatively (0%). The mean gain in bone height post-operatively was 10.31 ± 2.46 mm (p < 0.001). All implants successfully integrated (100% success rate) and were loaded with cement-retained prostheses. The proposed technique is a simple, efficacious, minimally invasive approach for sinus elevation that can be recommended for sites with at least 3 mm of residual height.

Five-year outcome of bone remodelling around implants in the maxillary sinus: assessment of differences between implants placed in autogenous inlay bone blocks and in ungrafted maxilla

The placement of implants in the posterior maxillary area is considered a reliable procedure, offering recognized rehabilitative advantages. The aim of this study was to evaluate the performance of dental implants placed in the sinus floor augmented with a block autograft by comparing the outcomes over 5 years with those of dental implants positioned in non-augmented bone. This retrospective cohort study included 16 patients who had undergone prosthetic rehabilitation supported by dental implants between 2000 and 2006. One implant per patient was included and assigned to one of two predictor groups: grafted versus ungrafted maxillary sinus. Changes in marginal bone level (MBL) and apical bone level (ABL) over time, at 1, 3, and 5 years, were the primary outcome variables. Appropriate pair-wise comparison tests were performed. No significant differences were seen with regard to ABLs and among times between the grafted group (nine implants) and the ungrafted group (seven implants). Significant marginal bone resorption was found over time, primarily at the buccal aspect, in both study groups. The bone surrounding the apex of dental implants appeared stable after sinus augmentation in the grafted area. The behaviour of the two groups with regard to loss of MBLs over time was very similar.

A 5-Year Implant Follow-Up in Maxillary and Mandibular Horizontal Osseous Onlay Grafts and Native Bone

The purpose of this study is to analyze marginal bone levels (MBLs) around dental implants positioned in the upper and lower jaw with or without horizontal onlay grafting procedures, and to survey implant survival with a follow-up of 5 years. Seventeen patients were surveyed in the present retrospective chart review. A total of 27 dental implants positioned in pristine bone and 21 in horizontally grafted bone were enrolled. MBLs were recorded for 4 aspects during a radiologic survey of 5 years. Significant differences were searched for among times and surgical procedures with paired and unpaired comparison tests, respectively, and survival rates were calculated for the 2 groups. In the maxilla, no statistically-significant differences between pristine and augmented groups were obtained; the time comparisons for pristine implants showed an affection of palatal, mesial, and distal sides, whereas the resorption around implants placed into horizontally grafted bone of anterior maxilla seemed to be limited just to buccal and distal aspects. Comparisons with the pristine horizontal procedure revealed that just the buccal sides were involved. The analysis of time comparisons attested to a continuous alveolar bone remodeling during the entire time of the survey for the pristine group. Given the extremely unfavorable resorption at the buccal aspect of the augmented areas, clinicians should reserve dental implant positioning into horizontal bone graft to selected patients, in whom it may represent one of the last opportunities of rehabilitation with a fixed prosthesis.