Randomized Clinical Trial of Maxillary Sinus Grafting using Deproteinized Porcine and Bovine Bone Mineral

In vivo experimental study comparing alveolar ridge preservation versus guided bone regeneration after unassisted socket healing at intact and damaged sites in narrow alveolar ridges

BACKGROUND

To compare bone regeneration and dimensional alteration of alveolar ridge at intact and damaged extraction sockets after alveolar ridge preservation (ARP) and implant placement versus unassisted socket healing followed by guided bone regeneration (GBR) with simultaneous implant placement.

METHODS

In 6 beagle dogs, 3 types of extraction sockets in the mandible were created: (1) intact sockets, (2) 1-wall defect sockets and (3) 2-wall defect sockets. The sockets were allocated to undergo either (1) ARP and implant placement 8 weeks later (ARP group) or (2) GBR with simultaneous implant placement after 8 weeks of unassisted socket healing (GBR group). After an additional healing period of 8 weeks, bone regeneration and dimensional changes were evaluated radiographically and histologically.

RESULTS

GBR showed superior bone formation and greater bone gains compared to ARP, regardless of the initial extraction-socket configuration. Although ARP maintained the preexisting alveolar ridge dimensions, peri-implant bone defects were still detected at 8 weeks of follow-up. Histomorphometric analyses confirmed that GBR increased dimensions of the alveolar ridge compared to baseline, and the augmentation and bone regeneration were greater with GBR than with ARP.

CONCLUSION

Early implant placement with ARP can mitigate alveolar ridge changes in the narrow alveolar ridge. However, early implant placement with simultaneous GBR creates the conditions for enhanced bone regeneration around the implant and greater ridge augmentation compared to ARP, irrespective of the extraction-socket configuration.

Does defect configuration affect the outcomes of alveolar ridge preservation? An experimental in vivo study

PURPOSE

The purpose of this study was to compare the bone healing potential of 1-, 2-, and 3-wall defects following alveolar ridge preservation (ARP) treatment, as well as to evaluate the efficacy of ARP as a treatment option for destructive sites.

METHODS

Three groups, characterized by 1-, 2-, and 3-wall defects, were randomly assigned to the maxillary second, third, and fourth premolars in each of 8 beagle dogs. Each defect was created at either the mesial or distal root site of the tooth, which was hemi-sectioned and extracted. The contralateral root was preserved to superimpose with the experimental site for histomorphometric analysis. For each site, either spontaneous healing (SH; control) or ARP (test intervention) was randomly applied. Each group was divided in half and underwent a healing period of either 4 or 12 weeks. The Mann-Whitney U test and Kruskal-Wallis test were used for histomorphometric analyses. Statistical significance was set at P<0.05.

RESULTS

Qualitative analysis revealed a higher percentage of new bone in the apical area compared to the coronal area, regardless of defect type and healing period. In quantitative analysis, the 3-wall defect exhibited a significantly higher percentage of mineralization in the ARP group after 12 weeks of healing (ARP: 61.73%±7.52%; SH: 48.84%±3.06%; P=0.029). An increased percentage of mineralization was observed with a greater number of remaining bony walls, although this finding did not reach statistical significance.

CONCLUSIONS

Within the limitations of this study, ARP treatment for compromised sockets appears to yield a higher percentage of mineralization compared to SH. Although the effectiveness of the remaining bony walls was limited, their presence appeared to improve the percentage of mineralization in ARP treatment.

Horizontal Guided Bone Regeneration of the Posterior Mandible to Allow Implant Placement: 1-Year Prospective Study Results

OBJECTIVE

Assess whether horizontal ridge augmentation with guided bone regeneration (GBR) using deproteinized bovine bone mineral (DBBM), autologous bone, and a resorbable collagen membrane supports successful implant placement.

MATERIALS AND METHODS

This open, prospective, single-cohort, multicenter clinical study included patients with ridge defects that required GBR prior to implant insertion. The primary endpoint was radiologically assessed bone gain after 8 months post-GBR, measured at the center of planned implant sites. Secondary endpoints included implant survival and success, marginal bone levels (MBLs), MBL changes, and soft tissue health.

RESULTS

Of 45 patients evaluated 8 months post-GBR, nine experienced dehiscence in the first 3 weeks of the healing period. GBR led to radiologically determined mean bone width gain of 4.0 ± 1.5 mm and 4.8 ± 1.7 mm, measured 1 and 3 mm from the top of the crest, respectively, allowing successful implant placement in 44 patients (97.8%). The cumulative implant survival and success rates were 98.9% and 95.5%, respectively. MBLs were stable: -1.18 ± 0.64 mm at definitive prosthesis placement (DPP) and - 1.07 ± 0.74 mm at 1 year. Soft tissue health and esthetics (plaque and bleeding indices, papilla, keratinized mucosa, and pink esthetic score) improved from DPP to 1 year. Patients were highly satisfied with implant function and esthetics, and their oral health-related quality of life improved.

CONCLUSIONS

GBR using DBBM and a collagen membrane offered a safe and effective treatment option for horizontal ridge augmentation sufficient to support implant-based tooth rehabilitation.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov NCT03028922 (registrations sites, as above listed affiliations, first posted January 23, 2017).

Fish: a new xenograft source for maxillary sinus lifting

OBJECTIVE

Although autogenous grafting is accepted as the gold standard in intraoral grafting, xenogenous grafts are frequently used in sinus lift surgeries due to their osteoinductive and osteoconductive properties. This study aimed to investigate the efficacy of fish spine-derived xenogenic grafts in sinus augmentation surgery.

MATERIAL AND METHODS

In this study, a fish spine-derived xenogenic graft was produced for comparison with autogenous graft and bovine derived xenogenic grafts. Twenty-one New Zealand rabbits were used. Autogenous grafts (AG- Group 1), as well as bovine-derived (bHAP - Group 2) and fish spine-derived (fHAP - Group 3) xenogenic grafts were placed in the right and left sinuses of rabbits. The animals were sacrificed at the 4th and 8th weeks. New bone formation (NBF) was evaluated through histological examination, while bone volume (BV), new bone surface/bone volume (BS-BV), new bone surface/tissue volume (BS-TV), and trabecular separation (Tb-Sp) were assessed via Micro-CT. Statistical significance was considered at p<0.05.

RESULTS

Histological examination revealed a significant difference in NBF between AG-bHAP (p<0.001), as well as between fHAP-bHAP (p<0.001) in the fourth-week group. No significant difference was found in the eighth-week group (p=0.130). In the eighth-week group, a statistically significant difference was found between fHAP and bHAP in terms of BV. (p=0.007).

CONCLUSION

Although both graft materials used in this study showed positive effects on bone regeneration, fHAP and AG presented similar effects on bone regeneration and were superior to bHAP.

Magnesium-enhanced porcine particles using hydrothermal technique improve the osteogenic differentiation of cells

Background: Guided bone regeneration (GBR) uses bone grafts and barrier membranes to block soft tissue invasion and eventually create a new bone. Some studies indicate that a porcine bone graft demonstrates excellent biocompatibility and holds promise as a xenograft for GBR. However, only a few studies have investigated the effectiveness of this biomaterial after magnesium coating in improving osteoblast performance. Aim: This study aimed to prove that the hydrothermal method can be used to coat magnesium oxide (MgO) on the surface of a porcine graft and enhance the biomaterial's property for better osteogenic differentiation of osteoblasts in vitro. Materials and Method: A porcine bone graft was produced, and the hydrothermal method was used to coat 2 mM and 5 mM of MgO on the graft. Material physiochemistry and biocompatibility analyses were performed at days 1, 3, and 5. Results: pH value assay results suggested that MgO slightly increased the alkalinity of the graft. SEM images showed that MgO with some surface roughness was coated on the porcine bone surface, and EDX indicated that the Mg and O element percentages increased by about 5% and 9%, respectively. The porcine graft coated with MgO was rougher than an uncoated porcine graft. FTIR analysis of the porcine graft implied that its chemical structure did not change due to MgO hydrothermal processing. Cell viability assay illustrated the highest cell proliferation with the porcine graft with 5 mM MgO (P < 0.001), and good cell attachment was observed on the graft with immunofluorescence using confocal laser scanning microscopy. Cell differentiation assay results revealed that the porcine graft with 5 mM MgO had the highest alkaline phosphate activity (P < 0.0001) among the uncoated porcine graft and the porcine graft with 2 mM MgO. Relative quantitative polymerase chain reaction (qPCR) at days 1 and 5 revealed upregulated osteoblast gene expression with a statistically significant difference. Conclusion: The porcine graft hydrothermally coated with 5 mM MgO was more biocompatible and enhanced osteoblast differentiation. Thus, the findings of this study indicate that a porcine graft with 5 mM MgO has great potential as a bio-bone graft for guided bone regeneration.

Three-dimensional volumetric assessment and stability of simultaneously placed implant following sinus floor augmentation with deproteinized human demineralized tooth matrix or deproteinized bovine bone mineral: a randomized controlled clinical trial

PURPOSE

This study aimed to analyze and compare three-dimensional volumetric bone changes and stability of simultaneously placed dental implants following sinus augmentation using deproteinized human demineralized tooth matrix (dpDTM) and deproteinized bovine bone mineral (DBBM).

METHODS

Twenty-four patients who required lateral maxillary sinus floor augmentation with simultaneous dental implant placement were randomly assigned to receive either dpDTM (n = 12) or DBBM (n = 12). Cone-beam computed tomography and resonance frequency analysis of implant stability were conducted immediately after surgery and 6 months postoperatively. Changes in the graft sinus floor and graft height volumes in the sagittal and coronal views, along with the implant stability quotient (ISQ), were analyzed and compared.

RESULTS

Volumetric graft alteration was comparable between dpDTM (120.33 ± 77.48 mm3) and DBBM (108.51 ± 65.15 mm3) (p = 0.690). Reduction in the average graft height was also comparable: dpDTM group ranged from - 0.59 to - 0.93 mm and the DBBM group ranged from - 0.55 to - 0.82 mm (p > 0.05) at most examined levels. However, greater reduction in the mesial-graft height occurred in the dpDTM group (- 1.08 ± 0.70 mm vs. -0.58 ± 0.39 mm, p = 0.04). The ISQ values increased similarly in both groups to reach 70 at 6 months.

CONCLUSION

dpDTM demonstrated comparable stability in graft volume and height during the healing process compared to DBBM and could serve as a viable alternative to DBBM for sinus floor augmentation with simultaneous implant placement.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect of Porcine- and Bovine-Derived Xenografts with Hydroxypropyl Methylcellulose for Bone Formation in Rabbit Calvaria Defects

In this study, hydroxypropyl methylcellulose (HPMC) was mixed with particle-type xenografts, derived from two different species (bovine and porcine), to increase the manipulability of bone grafts and compare the bone regeneration ability. Four circular defects with a diameter of 6 mm were formed on each rabbit calvaria, and the defects were randomly divided into three groups: no treatment (control group), HPMC-mixed bovine xenograft (Bo-Hy group), and HPMC-mixed porcine xenograft (Po-Hy group). At eight weeks, micro-computed tomography (µCT) scanning and histomorphometric analyses were performed to evaluate new bone formation within the defects. The results revealed that the defects treated with the Bo-Hy and the Po-Hy showed higher bone regeneration than the control group (p < 0.05), while there was no significant difference between the two xenograft groups (p > 0.05). Within the limitations of the present study, there was no difference in new bone formation between porcine and bovine xenografts with HPMC, and bone graft material was easily moldable with the desired shape during surgery. Therefore, the moldable porcine-derived xenograft with HPMC used in this study could be a promising substitute for the currently used bone grafts as it exhibits good bone regeneration ability for bony defects.

Residual Bone Height and New Bone Formation after Maxillary Sinus Augmentation Procedure Using Biomaterials: A Network Meta-Analysis of Clinical Trials

BACKGROUND

Different factors may affect new bone formation following maxillary sinus floor augmentation for the rehabilitation of posterior edentulous maxilla. The purpose of this study was to determine the influence of residual bone height (RBH) on new bone formation after lateral sinus augmentation utilizing different biomaterials, through a network meta-analysis (NMA).

METHODS

PUBMED, Scopus, and Web of Science electronic databases were searched until 31 December 2022 to obtain relevant articles. A hand search was also conducted. Randomised controlled studies on maxillary sinus augmentation comparing different grafting materials in patients with atrophic posterior maxilla, in need of prosthetic rehabilitation, were included. The risk of bias was assessed following the guidelines of the Cochrane Collaboration. The primary outcome was new bone formation (NBF), assessed histomorphometrically. The statistical analysis was performed by splitting the data according to RBH (<4 mm and ≥4 mm).

RESULTS

A total of 67 studies were eligible for conducting NMA. Overall, in the included studies, 1955 patients were treated and 2405 sinus augmentation procedures were performed. The biomaterials used were grouped into: autogenous bone (Auto), xenografts (XG), allografts (AG), alloplasts (AP), bioactive agents (Bio), hyaluronic acid (HA), and combinations of these. An inconsistency factor (IF) seen in the entire loop of the XG, AP, and Bio+AP was found to be statistically significant. The highest-ranked biomaterials for the <4 mm RBH outcome were XG+AG, XG+AP, and Auto. Similarly, the surface under the cumulative ranking curve (SUCRA) of biomaterials for ≥4 mm RBH was Auto, Bio+XG, and XG+Auto.

CONCLUSION

There is no grafting biomaterial that is consistently performing better than others. The performance of the materials in terms of NBF may depend on the RBH. While choosing a biomaterial, practitioners should consider both patient-specific aspects and sinus clinical characteristics.

The use of corticosteroids in the lateral sinus augmentation surgical procedure: A systematic review and meta-analysis

BACKGROUND

The lateral maxillary sinus augmentation (MSA) procedure has good predictability in terms of the success of bone regeneration with a low incidence of postoperative infections, estimated between 2% and 5.6%. Although the use of antibiotics is an established and standardized prophylactic measure for MSA procedures, the addition of corticosteroids still varies among clinician preference and clinical judgment.

PURPOSE

The aim of this systematic review was to identify whether the administration of corticosteroids during the MSA surgical procedure affects postoperative symptoms including swelling, pain, and infection rate.

MATERIALS AND METHODS

A literature search through PubMed, EMBASE, Ovid MEDLINE, and Web of Science indices, according to PICO criteria, was conducted to identify whether MSA peri-operative use of corticosteroids reduces the incidence of complications and patient morbidity. A single arm meta-analysis was performed due to the lack of randomized controlled trials (RCTs) comparing groups treated with or without peri-operative corticosteroids. The intracluster correlation co-efficient (ICC) and design effect were calculated to adjust for the clustering design.

RESULTS

In the 37 studies included, a total of 1599 patients (378 Cort, 1221 No-Cort) were analyzed. Before and after taking account of clustering, there was statistically significant effect of corticosteroids on swelling, pain, wound dehiscence, trismus, and hematoma. The complication rates postoperatively were comparable between the two study groups, however slight differences existed in the incidence of active suppuration (1.7% [95% CI 0.7-3.9] Cort vs. 3.2% [2.2-4.5] No-Cort), wound dehiscence (3.9% [1.3-11.2] Cort vs. 2.1% [1.0-4.1] No-Cort) and trismus (2.7% [0.8-8.4] Cort vs. 1.4% [0.8-2.5] No-Cort).

CONCLUSIONS

Although the event rate of the 1-to-2-week postoperative complications did not differ between the two groups, the lack of conclusive data and research comparing peri-operative corticosteroid use makes it impossible to draw definitive conclusions and more evidence and studies designed for this specific purpose are needed.

Efficacy of biologics for alveolar ridge preservation/reconstruction and implant site development: An American Academy of Periodontology best evidence systematic review

BACKGROUND

The use of biologics may be indicated for alveolar ridge preservation (ARP) and reconstruction (ARR), and implant site development (ISD). The present systematic review aimed to analyze the effect of autologous blood-derived products (ABPs), enamel matrix derivative (EMD), recombinant human platelet-derived growth factor-BB (rhPDGF-BB), and recombinant human bone morphogenetic protein-2 (rhBMP-2), on the outcomes of ARP/ARR and ISD therapy (i.e., alveolar ridge augmentation [ARA] and maxillary sinus floor augmentation [MSFA]).

METHODS

An electronic search for eligible articles published from January 2000 to October 2021 was conducted. Randomized clinical trials evaluating the efficacy of ABPs, EMD, rhBMP-2, and rhPDGF-BB for ARP/ARR and ISD were included according to pre-established eligibility criteria. Data on linear and volumetric dimensional changes, histomorphometric findings, and a variety of secondary outcomes (i.e., clinical, implant-related, digital imaging, safety, and patient-reported outcome measures [PROMs]) were extracted and critically analyzed. Risk of bias assessment of the selected investigations was also conducted.

RESULTS

A total of 39 articles were included and analyzed qualitatively. Due to the high level of heterogeneity across studies, quantitative analyses were not feasible. Most studies in the topic of ARP/ARR revealed that the use of biologics rendered similar results compared with conventional protocols. However, when juxtaposed to unassisted healing or socket filling using collagen sponges, the application of biologics did contribute to attenuate post-extraction alveolar ridge atrophy in most investigations. Additionally, histomorphometric outcomes were positively influenced by the application of biologics. The use of biologics in ARA interventions did not yield superior clinical or radiographic outcomes compared with control therapies. Nevertheless, ABPs enhanced new bone formation and reduced the likelihood of early wound dehiscence. The use of biologics in MSFA interventions did not translate into superior clinical or radiographic outcomes. It was observed, though, that the use of some biologics may promote bone formation during earlier stages of healing. Only four clinical investigations evaluated PROMs and reported a modest beneficial impact of the use of biologics on pain and swelling. No severe adverse events in association with the use of the biologics evaluated in this systematic review were noted.

CONCLUSIONS

Outcomes of therapy after post-extraction ARP/ARR and ARA in edentulous ridges were comparable among different therapeutic modalities evaluated in this systematic review. Nevertheless, the use of biologics (i.e., PRF, EMD, rhPDGF-BB, and rhBMP-2) in combination with a bone graft material generally results into superior histomorphometric outcomes and faster wound healing compared with control groups.

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.

A Randomized Controlled Trial of Guided Bone Regeneration for Peri-Implant Dehiscence Defects with Two Anorganic Bovine Bone Materials Covered by Titanium Meshes

The aim of this study is to compare two low-temperature sintered anorganic bovine bone materials (ABBMs), Bio-Oss (Geistlich, Wolhusen, Switzerland) and A-Oss (Osstem, Seoul, Korea), for GBR in dehiscence defects. A single implant was placed simultaneously with GBR in the buccal or bucco-proximal osseous defect by double-layering of inner allograft and outer ABBM, covered by a preformed ultrafine titanium mesh and an absorbable collagen membrane. Grafted volume changes were evaluated by cone-beam computed tomography, taken preoperatively (T0), immediately after implant surgery (T1), after re-entry surgery (T2), and after delivery of the final restoration (T3). The density of the regenerated bone was assessed by measuring the probing depth on the buccal mid-center of the mesh after removing the mesh at T2. Postoperative sequelae were also recorded. Grafted volume shrinkage of 46.0% (0.78 ± 0.37 cc) and 40.8% (0.79 ± 0.33 cc) in the Bio-Oss group (8 patients) and A-Oss group (8 patients), respectively, was observed at T3 (p < 0.001). There were no significant differences in grafted volume changes according to time periods or bone density between the two groups. Despite postoperative mesh exposure (3 patients), premature removal of these exposed meshes and additional grafting was not necessary, and all implants were functional over the 1-year follow-up period. Both ABBMs with titanium meshes showed no significant difference in the quantity and density of the regenerated bone after GBR for peri-implant defects.

Flapless osteotome-mediated sinus floor elevation using platelet-rich fibrin versus lateral approach using deproteinised bovine bone mineral for residual bone height of 2-6 mm: a randomised trial

OBJECTIVES

To evaluate patient-reported outcomes and radiographic results of simultaneous implant placement in severely atrophic maxilla using flapless endoscope-assisted osteotome sinus floor elevation with platelet-rich fibrin (PRF), also defined as PESS, and to compare the results with those of lateral sinus floor elevation (LSFE).

METHODS

Patients with a residual bone height (RBH) of 2-6 mm were included in a randomised controlled trial. PESS was performed with PRF as the sole grafting material. LSFE was performed using deproteinised bovine bone matrix. Patient-reported outcomes were recorded on a visual analogue scale (VAS-pain) and visual rating scale (VRS-swelling and VRS-willingness). Peri-implant bone height (PBH), bone mineral density (BMD), and sinus grafting remodelling index were measured using CBCT immediately postoperatively and 3^rd , 6^th and 18^th months post-surgery.

RESULTS

The study population consisted of 20 patients in each group. The RBH of two groups averaged 3.35±0.79 mm and 2.92±0.63 mm with no significant difference (p > 0.05). VAS-pain was 18.0 (IR 15.0-22.5) and 35.0 (IR 32.5-37.0) in the PESS and LSFE groups, respectively (p < 0.01). VAS-pain decreased with time in both groups. VRS-swelling was lower in the PESS group than LSFE group. VRS-willingness was higher in the PESS group than LSFE group (p < 0.01). At 18 months post-surgery, the marginal bone loss was 0.60±0.25 mm and 0.69±0.35 mm in the two groups with no significant difference (p = 0.52).

CONCLUSIONS

Within the limitations of this study, PESS was associated with lower postoperative morbidity and was more tolerable than LSFE. PESS could be a reliable procedure for sinus floor elevation in patients with insufficient RBH.

Maxillary sinus floor augmentation comparing bovine versus porcine bone xenografts mixed with autogenous bone graft. A split-mouth randomized controlled trial

Aim

To compare the effectiveness of two xenografts for maxillary sinus floor augmentation in terms of clinical, radiographical, histologic, and molecular outcomes.

Materials and methods

A split‐mouth randomized clinical trial was conducted at the University of Granada. Ten consecutive patients in need of bilateral two‐staged maxillary sinus floor augmentation were included. Each patient received both biomaterials (porcine bone mineral and anorganic bovine bone), which were randomly assigned for bilateral sinus augmentation. The maxillary autogenous bone scraped from the sinus access window was mixed with each xenograft at a 20:80 ratio. After a healing period of 6 months, bone biopsies were collected with a trephine during the implant placement in the regenerated area. Histologic, histomorphometrical, immunohistochemical, and molecular outcomes were analyzed. Clinical and radiographical data throughout the treatment phases were also evaluated.

Results

The resulting anatomic features were similar between both groups. After six months of graft consolidation, the graft resorption rates were similar between both biomaterials. The histologic, histomorphometrical, and immunohistochemical results showed no statistical differences between groups.

Conclusion

Anorganic bovine bone and porcine bone mineral combined with maxillary autogenous cortical bone show similar biologic and radiologic features in terms of biomaterial resorption, osteoconduction, and osteogenesis when used for maxillary sinus floor augmentation.

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

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Improved access to the bone marrow space by multiple perforations of the alveolar bundle bone after tooth extraction-A case report

Objectives

The dental alveolus is lined by a thin cortical layer (“bundle bone”, “alveolar bone proper”, “cribriform plate”, “lamina dura”), that can impede access to the bone marrow and its vasculature. During unassisted socket healing, the alveolar bundle bone is gradually resorbed allowing tissue resources from the bone marrow to enter into the socket space. An optimized wound healing process, either during unassisted socket healing or during ridge preservation procedures, with autogenous bone and/or any bone/collagen substitute material, depends at least partly on an adequate vascularization of the socket space. This ensures sufficient recruitment of osteoblast and osteoclast precursor cells and facilitates fast bone regeneration and/or uneventful integration of the augmentation material.

Methods

The present technical note describes an easy treatment step after tooth extraction aiming to improve socket healing with or without any ridge preservation procedure, by facilitating an increased blood inflow into the dental alveolus. Specifically, after tooth extraction the alveolar bundle bone is perforated several times – mainly in a palatally/lingually – by a small round bur (diameter < 1 mm) extending into the trabecular bone.

Results and conclusions

By means of this relatively simple treatment step, an increased blood inflow into the alveolus is achieved after tooth extraction, which might enhance socket healing and corticalization of the entrance, and in turn result in a lower complication rate (e.g., dry socket), in an enhanced graft incorporation, and/or in a reduced loss of alveolar ridge volume.

Osteoconductivity of Bovine Xenograft Granules of Different Sizes in Sinus Lift: A Histomorphometric Study in Rabbits

Background: Due to the lack of data on bone-to-graft contact (BGC) over time in the various regions within the subantral space of the augmented sinus floor, the present study aimed to evaluate the osteoconductivity of deproteinized bovine bone mineral (DBBM) with granules of different sizes applied in maxillary sinus floor elevation. Methods: A maxillary sinus augmentation was performed bilaterally in 18 rabbits using DBBM with particle dimensions of either 0.125–1.0 mm or 1–2 mm. The antrostomy was covered using a collagen barrier. The animals were euthanized in groups of six after 2, 4, and 8 weeks of healing. MicroCT and histological analyses were performed. Results: After 2 weeks of healing, BGC was 10.9% and 11.9% for the small and large granule sites, respectively. After 8 weeks of healing, the BGC increased to 65% and 62% at the small and large granule sites, respectively. The highest values were located close to the bony walls and the bony window. New bone content developed between 2 and 8 weeks from 7.0% to 27.6% and from 6.1% to 27.6% at the small and large granule sites, respectively. Conclusions: Similar outcomes in osteoconductivity and bone formation were found at both small and large DBBM granule sites.

Xenograft materials in maxillary sinus floor elevation surgery: a systematic review with network meta-analyses

A systematic review and network meta-analysis was conducted to compare different commercially available xenograft materials used in maxillary sinus floor elevation surgery (MSFES). Embase, PubMed, the Cochrane Library, Web of Science, Scopus, LILACS, and grey literature were searched up to 13 July 2020. Only randomised controlled trials (RCTs) were included. A frequentist network meta-analysis using a random effects model compared different commercially available xenograft materials. The primary outcomes were the percentage of newly-formed bone and residual bone-substitute rate. Both were measured by histomorphometric analysis from bone biopsies obtained during preparation of the implant site. Of the 659 studies initially identified, 11 involving 242 MSFES were included in the quantitative analyses. A total of six bone-substitute materials were analysed (Bio-Oss® (Geistlich Pharma), InduCera® Dual Coat, Lumina-Bone Porous® (Critéria), Osseous® (SIN - Sistema de Implantes Nacional), THE Graft® (Purgo Biologics), and Osteoplant Osteoxenon® (Bioteck)). The P-score estimation showed that Osteoplant Osteoxenon® produced the most newly-formed bone and reabsorbed faster than other xenograft materials after six months. The combination of Bio-Oss® plus bone marrow aspirate concentrate (BMAC) significantly increased the percentage of newly-formed bone compared with Bio-Oss® alone. In contrast, the addition of Emdogain® (Straumann) and leucocyte and platelet-rich fibrin (L-PRF) to Bio-Oss® did not significantly improve the amount of regenerated bone. Study-level data indicated that the percentage of newly-formed bone differs among commercially available xenograft materials. Osteoplant Osteoxenon® seems to result in the highest amount of new bone in MSFES.

Relative performance of various biomaterials used for maxillary sinus augmentation: A Bayesian network meta-analysis

Objectives

To assess the histomorphometric outcomes obtained in randomized clinical trials (RCTs) with different biomaterials used for maxillary sinus augmentation (MSA).

Materials and Methods

A search of the existing medical literature until October 1, 2019, was performed. Inclusion criteria were (a) RCTs assessing a two‐stage MSA from the lateral approach using autologous bone or biomaterials for grafting and (b) reported histomorphometric outcomes based on crestal bone core biopsy samples. The Bayesian method was used to perform pairwise meta‐analyses and network meta‐analysis (NMA). The primary outcome, the new bone percentage (NB %), was calculated as mean differences with 95% credible intervals. The interventions were ranked by their posterior probability by calculating the surface under the cumulative ranking curve values.

Results

Thirty‐four RCTs (842 MSAs) were included in the analysis with a normal healing period (5–8 months). All comparisons were presented in a league table. On the basis of the ranking probability, the most effective bone grafting material for NB% was bovine xenograft + bone marrow concentrate (BMC) (81%), followed by bovine xenograft + platelet‐rich plasma (PRP) (77%), bioactive glass ceramic + autologous bone 1:1 (70%), nanocrystalline hydroxyapatite in silica gel (70%), and bioactive glass ceramic (70%). Autologous bone graft alone took the twelfth position with 57%.

Conclusion

Within the limitations of the present NMA, the analysis did not confirm autologous bone alone as the gold standard for MSA and showed superiority of composite grafts such as bovine xenograft + BMC after 5–8 months of healing.

The new bone formation in human maxillary sinuses using two bone substitutes with different resorption types associated or not with autogenous bone graft: a comparative histomorphometric, immunohistochemical and randomized clinical study

OBJECTIVE

The aim of this study is to evaluate the new bone and connective tissue formation and the biomaterial remaining after maxillary sinus bone augmentation using 5 different bone substitutes. The osteocalcin immunolabeling was performed to demonstrate their calcification and the possibility of receiving dental implants.

METHODOLOGY

40 patients underwent maxillary sinus bone augmentation and were divided in 5 groups: Group 1 with 8 maxillary sinuses were grafted with autogenous bone graft (AB); Group 2 with 8 maxillary sinuses grafted with bioactive glass (BG); Group 3 with 8 maxillary sinuses grafted with bioactive glass added to autogenous bone graft (BG + AB) 1:1; Group 4 with 8 maxillary sinuses grafted with Bio-Oss (BO) and Group 5 with 8 maxillary sinuses grafted with Bio-Oss added to autogenous bone graft (BO + AB) 1:1.

RESULTS

In group AB, 37.8% of bone was formed in the pristine bone region, 38.1% in the intermediate and 44.5% in the apical region. In group BG, 43.6% was formed in the pristine bone, 37% in the intermediate and 49.3% in the apical region. In group BG + AB 1:1, 39.0% was formed in the pristine bone region, 34.8% in the intermediate and 36.8% in apical region. In group BO, 33.4% was formed in the pristine bone, 32.5% in the intermediate and 34.3% in the apical region. In group BO + AB 1:1, 32.8% was formed in the pristine bone, 36.1% in intermediate and 27.8% in the apical regions. The immunolabeling for osteocalcin showed an intensive staining for all groups, which could demonstrate the calcification of the bone formed.

CONCLUSION

This study showed that the groups evaluated formed a suitable lamellar bone in the maxillary sinus reconstruction after six months of bone healing, thus being indicated to receive dental implants.

Biomimetic Aspects of Oral and Dentofacial Regeneration

Biomimetic materials for hard and soft tissues have advanced in the fields of tissue engineering and regenerative medicine in dentistry. To examine these recent advances, we searched Medline (OVID) with the key terms “biomimetics”, “biomaterials”, and “biomimicry” combined with MeSH terms for “dentistry” and limited the date of publication between 2010–2020. Over 500 articles were obtained under clinical trials, randomized clinical trials, metanalysis, and systematic reviews developed in the past 10 years in three major areas of dentistry: restorative, orofacial surgery, and periodontics. Clinical studies and systematic reviews along with hand-searched preclinical studies as potential therapies have been included. They support the proof-of-concept that novel treatments are in the pipeline towards ground-breaking clinical therapies for orofacial bone regeneration, tooth regeneration, repair of the oral mucosa, periodontal tissue engineering, and dental implants. Biomimicry enhances the clinical outcomes and calls for an interdisciplinary approach integrating medicine, bioengineering, biotechnology, and computational sciences to advance the current research to clinics. We conclude that dentistry has come a long way apropos of regenerative medicine; still, there are vast avenues to endeavour, seeking inspiration from other facets in biomedical research.

Dimensional changes of the maxillary sinus augmented with a collagenated synthetic bone block or synthetic bone particulates: A pre-clinical study in rabbits

OBJECTIVE

To compare the efficacy of a collagenated synthetic bone substitute (C-SBS) to a particulated synthetic bone substitute (P-SBS) in volume maintenance and new bone formations in a rabbit sinus model.

MATERIALS AND METHODS

Either C-SBS or P-SBS was grafted in both sinuses of 16 rabbits. Four (N = 8) or 12 (N = 8) weeks after the surgery, total augmented volume (TAV) and area (TAA), as well as new bone volume (NBV) and area (NBA), were statistically compared by radiographic and histomorphometric analyses (p < .05).

RESULTS

The differences in TAV, NBV, TAA and NBA between C-SBS and P-SBS groups at 4 weeks were not statistically significant. The TAV (267.13 ± 62.08 vs. 200.18 ± 40.32 mm³ ) and NBV (103.26 ± 10.50 vs. 71.10 ± 7.58 mm³ ) in group C-SBS were significantly higher than in group P-SBS at 12 weeks (p < .05). The TAA (19.36 ± 2.88 vs. 14.48 ± 2.08 mm² ) and NBA (5.43 ± 1.20 vs. 3.76 ± 0.78 mm² ) in group C-SBS were significantly higher than in group P-SBS at 12 weeks (p < .05).

CONCLUSIONS

Collagenated synthetic bone substitute grafted in rabbit sinuses demonstrated more favourable outcomes across all outcome measures compared to P-SBS at 12 weeks.

Maxillary sinus floor elevation using hydroxyapatite nano particles vs tenting technique with simultaneous implant placement: A randomized clinical trial

PURPOSE

The present study was conducted to evaluate the amount of bone height gain, density values, and implant stability after maxillary sinus floor elevation using graftless tenting technique or the use of Hydroxyapatite Nanoparticles bone substitute for augmentation with simultaneous implant placement.

MATERIALS AND METHODS

A total of 20 sinuses with a residual alveolar bone height ranging from 4-6 mm were divided into two groups and underwent sinus augmentation using nano hydroxyapatite bone substitute material and the graftless tenting technique with simultaneous implant placement. Computed tomography CT scans and ISQ measurements were conducted to evaluate bone quality, quantity, and implant stability.

RESULTS

Radiographic analysis revealed that the mean bone height gain of the nano group was (7.0 ± 0.8 mm) compared to (5.0 ± 1.5 mm) in the tent group, which was statistically significant (P = .002) being higher in the nano group. The mean bone density value of the nano group was (548 ± 25 HU) compared to (420 ± 23 HU) in the tent group, which was statistically significant (P < .001) being higher in the nano group. The mean ISQ value after 6 months in the nano group was (78 ± 5) compared to (77 ± 5) in the tent group, which was statistically nonsignificant (P = .901).

CONCLUSION

Nano hydroxyapatite bone graft offered superior results in terms of the bone height gain and the relative bone density as compared to graftless tenting technique. However, both techniques showed accepted results regarding implant stability.

Comparative preclinical assessment of the use of dehydrated human amnion/chorion membrane to repair perforated sinus membranes

Purpose

The aim of this study was to evaluate the use of dehydrated human amnion/chorion membrane (dHACM) to repair perforated sinus membranes in rabbits.

Methods

Bilateral surgical windows (7.5-mm diameter) were prepared on the nasal bones of 14 rabbits. Standardized circular perforations (5-mm diameter) were made in the sinus membrane by manipulating implant twist drills. The perforated sinus membranes were repaired using dHACM or a resorbable collagen membrane (CM). The negative control (NC) group did not undergo perforated sinus membrane repair, while the positive control (PC) group underwent sinus augmentation without perforations. The same amount of deproteinized porcine bone mineral was grafted in all 4 groups. After 6 weeks, micro-computed tomography (micro-CT) and histomorphometric evaluations were conducted.

Results

The micro-CT analysis revealed that the total augmented volume was not significantly different among the groups. In the dHACM group, newly formed bone filled the augmented area with remaining biomaterials; however, non-ciliated flat epithelium and inflammatory cells were observed on the healed sinus membrane. Histometric analysis showed that the percentage of newly formed bone area in the dHACM group did not differ significantly from that in the CM group. The dHACM group showed a significantly higher percentage of newly formed bone area than the NC group, but there was no significant difference between the dHACM and PC groups.

Conclusions

dHACM could be a feasible solution for repairing sinus membrane perforations that occur during sinus floor augmentation.

Void space and long-term volumetric changes of maxillary sinus floor augmentation with comparison between hydroxyapatite soaked with bone morphogenetic protein 2 and anorganic bovine xenograft alone

PURPOSE

We hypothesized that the void volume after maxillary sinus floor augmentation (MSFA) with recombinant human bone morphogenetic protein-2 (rhBMP-2) would be larger than that without rhBMP-2, and filled with bone in the long term. The aim of this study was to analyze the occurrence of void space and long-term volumetric changes after MSFA with rhBMP-2 and hydroxyapatite (BMP-2/H).

MATERIAL AND METHODS

In 25 subjects, MSFA was performed with BMP-2/H (group I) or an anorganic bovine xenograft (group II). Computed tomography scans were taken twice, at 3 months (T1) and at least 24 months (T2) after surgery. Total volume (TV), bone volume (BV), and void volume (VV) were measured and analysed statistically.

RESULTS

While similar amounts of graft material were used, the TV was significantly larger in group I than in group II (p = 0.014). The VV showed a tendency to be larger in group I than in group II. VV reduction up to T2 was significantly greater in group I than in group II. Consequently, the BV at T2 was significantly greater in group I than in group II by 36% (p = 0.014).

CONCLUSION

This study showed that our hypothesis was valid. rhBMP-2 is effective for long-term bone regeneration after MSFA.

Maxillary Sinus Augmentation With Calcium Phosphate Double-Coated Anorganic Bovine Bone: Comparative Multicenter Randomized Clinical Trial With Histological and Radiographic Evaluation

PURPOSE

The purpose of this study was to evaluate the clinical, histological and radiographic outcomes of the calcium phosphate double-coated anorganic bovine bone (InduCera; Oscotec Inc., Seongnam, Gyeonggi, Republic of Korea) compared with that of anorganic bovine bone (Bio-Oss; Geistlich Biomaterials, Wolhusen, Switzerland) in maxillary sinus augmentation, prospectively.

PATIENTS AND METHODS

Twenty-eight sinuses in 25 patients (3 bilateral) with vertical alveolar bone height from 2 to 5 mm were included in this study. The maxillary sinus was augmented with InduCera or Bio-Oss, followed by a healing period of 6 months. Trephine cores were obtained for histomorphometric evaluation with the implant placement. Cone-beam computed tomography (CBCT) scans were taken at 1 week and 6 months after sinus augmentation.

RESULTS

The graft sites were healed without any notable complications in both groups. In histomorphometric analysis, the area of the newly formed bone was measured as 21.37 ± 8.87% for InduCera and 23.02 ± 5.88% for Bio-Oss, with no significant differences. Radiographically, no statistically significant differences were calculated between the groups in bone height at baseline, the height of bone augmentation, the final alveolar bone height (alveolar bone height + augmented height) after 6 months in panoramic radiograph. There were also no significant differences in the shrinkage rate of the grafted area volume in CBCT.

CONCLUSION

Although calcium phosphate double-coated anorganic bovine bone showed no additional effect compared with anorganic bovine bone from a histological and radiographical point of view, it could be used as the bone graft material in maxillary sinus augmentation.

Bovine bone particulates containing bone anabolic factors as a potential xenogenic bone graft substitute

Background

Alternative grafts are needed to improve the healing of bone non-union. Here, we assessed a bovine bone product which retains the inorganic and organic components of bone, as an alternative bone graft.

Methods

Bovine bone matrix proteins (BBMPs) were isolated from bovine bone particulates (BBPs) and tested in vitro. Primary rat osteoblast viability, differentiation, and mineralisation were assessed with alamarBlue®, real-time PCR, and von Kossa staining assays, respectively. Osteoclast formation was assessed in primary murine bone marrow cultures with TRAP staining.

Human osteoblast growth and differentiation in the presence of BBPs was evaluated in 3D collagen gels in vitro using alamarBlue® and real-time PCR, respectively. The efficacy of BBPs as an alternative bone graft was tested in a rat critical-size calvarial defect model, with histology scored at 4 and 12 weeks post-surgery.

Results

In vitro, the highest concentration of BBMPs increased mineral deposition five-fold compared to the untreated control group (P < 0.05); enhanced the expression of key osteoblast genes encoding for RUNX2, alkaline phosphatase, and osteocalcin (P < 0.05); and decreased osteoclast formation three-fold, compared to the untreated control group (P < 0.05).

However, the BBPs had no effect on primary human osteoblasts in vitro, and in vivo, no difference was found in healing between the BBP-treated group and the untreated control group.

Conclusions

Overall, despite the positive effects of the BBMPs on the cells of the bone, the bovine bone product as a whole did not enhance bone healing. Finding a way to harness the positive effect of these BBMPs would provide a clear benefit for healing bone non-union.

Bone regeneration using three-dimensional hexahedron channel structured BCP block in rabbit calvarial defects

The purpose of this study is to evaluate the efficacy of bone regeneration and volume maintenance of the three-dimensional (3D) structured biphasic calcium phosphate (BCP) block with porous hexahedron channels in a rabbit calvarial model. In this work, four circular defects (diameter: 8 mm) in calvarium of rabbits were randomly assigned to (1) negative control (control), (2) 3D hexahedron channel structured BCP block, (3) deproteinized bovine bone mineral particle, and (4) deproteinized porcine bone mineral particle. Animals were euthanized at 2 (n = 5) and 8 weeks (n = 5). Outcome measures included micro-computed tomography (CT) and histomorphometrical analysis. Results indicated that in micro-CT, BCP group showed the highest new bone volume with significant difference compared to control (p = 0.008) at 8 weeks. Histomorphometrically, total augmented area of BCP group was the highest with significant difference compared to control (p = 0.008) at 8 weeks. BCP group also maintained total volume of the original defect without collapsing. BCP block with 3D hexahedron channel structure seems to have favorable osteogenic and volume maintaining ability and highly porous structure might attribute to new bone formation. Further studies regarding the optimal internal structure and porosity of the BCP block bone substitute are needed. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2254-2262, 2019.

Multiple Perforations of the Sinus Floor During Maxillary Sinus Floor Augmentation to Provide Access to the Bone Marrow Space: A Technical Report

INTRODUCTION

Sinus floor augmentation is a routinely used surgical technique for increasing the bone height/volume of the atrophic posterior maxilla. Optimal integration of the implanted augmentation material within the newly formed bone will-at least partly-depend on adequate vascularization to ensure sufficient recruitment of osteoblast and osteoclast precursor cells.

METHODS

The present technical note describes a modification intended to facilitate increased blood inflow into the augmented space. After preparation of the lateral window and elevation of the Schneiderian membrane, the cortical bone of the sinus floor is perforated several times either by using a piezoelectric device or a microsurgical handpiece with the corresponding tip or bur; these perforations should extend into the trabecular bone.

RESULTS AND CONCLUSION

The experiences with this modified technique after 12 patients are presented and discussed. It is expected that by means of this relatively simple technique, increased blood and cell inflow into the augmented space is achieved. This may, in turn, enhance new bone formation and improve the integration of the augmentation material.

Alveolar ridge regeneration of damaged extraction sockets using deproteinized porcine versus bovine bone minerals: A randomized clinical trial

Backgrounds

Clinical benefits in bone grafting of intact extraction socket have been widely known, but limited evidence is available for the procedure in damaged extraction sockets due to periodontal disease.

Purpose

This study aimed to determine the dimensional alteration of alveolar ridge following bone grafting of damaged extraction sockets, and compare the outcomes of using deproteinized bovine (DBBM) versus porcine bone mineral (DPBM) in the damaged sockets.

Materials and Methods

One hundred patients (n = 50 for each group) with periodontitis‐induced damaged extraction socket were included in this randomized, single‐blind trial. After removal of tooth and granulation tissue, sites were grafted with either DBBM (DBBM group) or DPBM (DPBM group), and covered with collagen membrane. Linear/volumetric analyses of hard and soft‐tissue dimensions were performed on reconstructed/superimposed computed tomography and scanned cast images, taken immediately and 4 months after surgery.

Results

The two groups showed comparable hard tissue augmentation with minimal reductions in the grafted volume, as well as in vertical (1.22 ± 2.16 and 1.45 ± 1.92 mm for DPBM and DBBM group, respectively) and horizontal (1.43 ± 3.40 and 1.83 ± 2.85 mm on the central section, respectively) dimensions at 4 months after surgery. However, several cases showed large variations in maintenance of the grafted volume. None of the measured parameters in hard and soft tissue dimensions differed significantly between DBBM and DPBM sites.

Conclusions

DBBM and DPBM can comparably augment damaged extraction sockets with minimal postoperative reduction of the grafted volume. However, the large variations in the results should be further evaluated for application in routine dental clinics.

Guided maxillary sinus floor elevation using deproteinized bovine bone versus graftless Schneiderian membrane elevation with simultaneous implant placement: Randomized clinical trial

OBJECTIVE

The aim of this study is to evaluate the analytical difference between the use of xenograft (control group) and graftless tenting (test group) technique after sinus lift procedure with simultaneous implant placement.

MATERIALS AND METHODS

Seventeen patients and 20 sinuses where operated for sinus lift procedures using lateral window approach with simultaneous implant placement. Deproteinized bovine bone (Xenograft) was used as a filling material in control group while nongrafted sinus lifting was performed in the test group. Multislice CT was obtained preoperatively and CBCT were obtained immediately postoperative and 6 months after operation. Osstell readings were taken at the time of implant placement and implant exposure (6 months) RESULTS: Mean bone height gain in the xenograft group was 8.59 ± 0.74 while that of the tenting group was 4.85 ± 0.5 and it was statistically significant (P < .05). Mean bone density values in the xenograft group was 375.59 ± 49.38 while that of the tenting group was 269.08 ± 16.27 and it was statistically significant (P < .05). Mean ISQ values for the xenograft group was 78.3 ± 5.08 while that of the tenting group was 74 ± 3.19 and it was statistically significant (P < .05).

CONCLUSIONS

Within the limitation of this study, sinus lift procedures with simultaneous implant placement using xenograft as a filling material or graftless technique are considered reliable procedures, however, the use of xenograft provide better results in all aspects regarding (bone height gain, bone density, and implant stability).

Comparative study of volumetric changes and trabecular microarchitecture in human maxillary sinus bone augmentation with bioactive glass and autogenous bone graft: a prospective and randomized assessment

The aim of this study was to compare the volumetric changes and the new bone microarchitecture in human maxillary sinuses augmented with bioactive glass (Biogran) alone, bioactive glass combined with autogenous bone graft (1:1), or autogenous bone graft alone. Twelve maxillary sinuses were grafted with bioactive glass (group 1), nine with bioactive glass mixed with autogenous bone graft 1:1 (group 2), and 12 with autogenous bone graft (group 3). Patients underwent cone beam computed tomography 15days after the procedure to determine the initial volume of the graft (T1) and again 6 months later (T2). Biopsies were obtained at the time of dental implant placement and were subjected to micro-computed tomography. The volumetric change was 44.2% in group 1, 37.9% in group 2, and 45.7% in group 3 (P>0.05). The trabecular microarchitecture results showed that the materials used in groups 1 and 2 were good bone substitutes. However, the addition of 50% bioactive glass to autogenous bone graft improved the microarchitecture of the graft. Furthermore, the results for volumetric changes indicated that bioactive glass, its association with autogenous bone graft in a 1:1 ratio, and autogenous bone graft alone have similar resorption.

Attributes of Bio-Oss® and Moa-Bone® graft materials in a pilot study using the sheep maxillary sinus model

BACKGROUND AND OBJECTIVE

The aim of this pilot study was to characterize surface morphology and to evaluate resorption and osseous healing of two deproteinated bovine bone graft materials after sinus grafting in a large animal model.

MATERIAL AND METHODS

Surfaces of a novel particulate bovine bone graft, Moa-Bone^® were compared with Bio-Oss^® using scanning electron microscopy. Six sheep then had maxillary sinus grafting bilaterally, covered with BioGide^® . Grafted maxillae were harvested after 4, 6 and 12 weeks. Healing was described for half of each site using resin-embedded ground sections. For the other half, paraffin-embedded sections were examined using tartrate resistant acid phosphatase staining for osteoclast activity, runt-related transcription factor2 immunohistochemistry for pre-osteoblasts and osteoblasts and proliferating cell nuclear antigen for proliferative cells.

RESULTS

Moa-Bone^® had a smoother, more porous fibrous structure with minimal globular particles compared with Bio-Oss^® . After 4 weeks, woven bone formed on both grafts and the Moa-Bone^® particles also showed signs of resorption. After 12 weeks, Moa-Bone^® continued to be resorbed, however Bio-Oss^® did not; both grafts were surrounded by maturing lamellar bone. Moa-Bone^® was associated with earlier evidence of runt-related transcription factor 2-positive cells. Moa-Bone^® but not Bio-Oss^® was associated with strong tartrate resistant acid phosphatase-positive osteoclasts on the graft surface within resorption lacunae at both 4 and 6 weeks post-grafting.

CONCLUSION

Both materials supported osseous healing and maturation without inflammation. Moa-Bone^® showed marked osteoclast activity after 4 and 6 weeks and demonstrated positive attributes for grafting, if complete remodeling of the graft within the site is desired. Further optimization of Moa-Bone^® for maxillofacial applications is warranted.

Comparison of Two Xenograft Materials Used in Sinus Lift Procedures: Material Characterization and In Vivo Behavior

Detailed information about graft material characteristic is crucial to evaluate their clinical outcomes. The present study evaluates the physico-chemical characteristics of two xenografts manufactured on an industrial scale deproteinized at different temperatures (non-sintered and sintered) in accordance with a protocol previously used in sinus lift procedures. It compares how the physico-chemical properties influence the material’s performance in vivo by a histomorphometric study in retrieved bone biopsies following maxillary sinus augmentation in 10 clinical cases. An X-ray diffraction analysis revealed the typical structure of hydroxyapatite (HA) for both materials. Both xenografts were porous and exhibited intraparticle pores. Strong differences were observed in terms of porosity, crystallinity, and calcium/phosphate. Histomorphometric measurements on the bone biopsies showed statistically significant differences. The physic-chemical assessment of both xenografts, made in accordance with the protocol developed on an industrial scale, confirmed that these products present excellent biocompatibilitity, with similar characteristics to natural bone. The sintered HA xenografts exhibited greater osteoconductivity, but were not completely resorbable (30.80 ± 0.88% residual material). The non-sintered HA xenografts induced about 25.92 ± 1.61% of new bone and a high level of degradation after six months of implantation. Differences in the physico-chemical characteristics found between the two HA xenografts determined a different behavior for this material.

SEM-EDX Study of the Degradation Process of Two Xenograft Materials Used in Sinus Lift Procedures

Some studies have demonstrated that in vivo degradation processes are influenced by the material’s physico-chemical properties. The present study compares two hydroxyapatites manufactured on an industrial scale, deproteinized at low and high temperatures, and how physico-chemical properties can influence the mineral degradation process of material performance in bone biopsies retrieved six months after maxillary sinus augmentation. Residual biomaterial particles were examined by field scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) to determine the composition and degree of degradation of the bone graft substitute material. According to the EDX analysis, the Ca/P ratio significantly lowered in the residual biomaterial (1.08 ± 0.32) compared to the initial composition (2.22 ± 0.08) for the low-temperature sintered group, which also presented high porosity, low crystallinity, low density, a large surface area, poor stability, and a high resorption rate compared to the high-temperature sintered material. This demonstrates that variations in the physico-chemical properties of bone substitute material clearly influence the degradation process. Further studies are needed to determine whether the resorption of deproteinized bone particles proceeds slowly enough to allow sufficient time for bone maturation to occur.

Maxillary Sinus Augmentation with Decellularized Bovine Compact Particles: A Radiological, Clinical, and Histologic Report of 4 Cases

Background. One of the most problematic regions for endosseous implants is the posterior maxilla, not only having poor bone density, but also lacking adequate vertical height as a result of sinus pneumatization. The purpose of the present study was a radiologic, histological, and histomorphometrical evaluation, in humans, of specimens retrieved from sinuses augmented with decellularized bovine compact particles, after a healing period of 6 months. Methods. Four patients, with atrophic resorbed maxillas, underwent a sinus lift augmentation with decellularized bovine compact bone from bovine femur. The size of the particles used was 0.25–1 mm. A total of four grafts and 5 biopsies were retrieved and processed to obtain thin ground sections with the Precise 1 Automated System. Results. The mean volume after graft elevation calculated for each of the 4 patients was 2106 mm³ in the immediate postoperative period (5–7 days), ranging from 1408.8 to 2946.4 mm³. In the late postoperative period (6 months) it was 2053 mm³, ranging from 1339.9 to 2808.9 mm³. Histomorphometry showed that newly formed bone was 36 ± 1.6% and marrow spaces were 34 ± 1.6%, while the residual graft material was 35 ± 1.4%. Conclusion. In conclusion, based on the outcome of the present study, Re-Bone® can be used with success in sinus augmentation procedures and 6 months are considered an adequate time for maturation before implant placement.