Anorganic bovine bone (ABB) vs. autologous bone (AB) plus ABB in maxillary sinus grafting. A prospective non-randomized clinical and histomorphometrical trial

Bovine-originated xenografts versus synthetic bone grafting materials in lateral maxillary sinus floor augmentation: A systematic review and meta-analysis

AIMS

This study aimed to systematically compare the patients undergoing lateral MSFA therapies utilizing bovine-originated xenografts versus varied synthetic bone grafting materials.

METHODS

Pubmed, Scopus, Embase, and Cochrane Library were searched up to April 2023, compensated by a manual search in selected journals. Studies reporting histological outcomes (residual bone graft, newly formed bone, non-mineralized tissue) and clinical outcomes (implant survival, ISQ value) were included. Several analyses were performed, including meta-analysis, sensitivity study, and Egger's regression tests.

RESULTS

Sixteen clinical/randomized control trials were included in this systematic review, among which 12 were enrolled in a meta-analysis. The percentage of newly formed bone within the grafted sinuses by hybrid HA/TCP was significantly higher than those by xenografts (WMD 2.85, 95%CI [0.72; 4.99]), but those grafted by pure HA (WMD -1.72, 95%CI [-3.15; -0.29]) or TCP (WMD -7.10, 95%CI [-13.02; -1.17]) were significantly lower than xenograft counterparts. The residual bone graft and non-mineralized tissue yielded by synthetic HA, TCP, and HA/TCP showed no significant differences with the xenograft group.

CONCLUSION

The chemistry of grafted bone substitutes in lateral MSFA influenced the quantity of newly formed bone. Those grafted with hybrid HA/TCP yielded the highest amount of new bone compared to bovine-originated HA. However, this influence was not significant on residual bone graft and non-mineralized tissue.

Maxillary sinus lift augmentation: A randomized clinical trial with histological data comparing deproteinized bovine bone grafting vs graftless procedure with a 5-12-year follow-up

INTRODUCTION

Different protocols and procedures for sinus lift and implant placement are available, generally involving the use of grafts to increase the tissue volume and/or prevent the Schneiderian membrane from collapsing. Among xenografts, deproteinised bovine bone graft (DBBP) is frequently used in sinus lift procedures. Leaving an ungrafted space following membrane elevation has proven to have a bony regenerative potential as well. This study aimed to compare the clinical and histological features of sinus lift surgery performed with or without biomaterials.

METHODS

Patients with severe maxillary posterior atrophy (residual bone height 2-6 mm and residual crest thickness ≥4 mm), and in need of sinus lift surgery to allow the placement of three implants were enrolled and randomly divided into two groups. They underwent sinus lifts with DBBP (control) or with a graftless technique (test) and immediate placement of two implants (a mesial and distal one). After 6 months, a bone sample was retrieved from the area between the previously inserted fixtures, and a third, central implant was placed. The collected bone samples were analyzed morphologically and histomorphometrically. The patients were provided with prosthetic restorations after 6 months and followed up for 5-12 years.

RESULTS

Ten patients were enrolled in the test and nine in the control group. The 6-month follow-up showed in the control group an average augmentation of 10.31 mm (±2.12), while in the test group it was 8.5 mm (±1.41) and a success rate of 96.3% in the control and 86.7% in the test group (p > 0.05). The histological analysis evidenced the presence of new bone tissue surrounded by immature osteoid matrix in the test group, and a variable number of DBBP particles surrounded by an immature woven bone matrix in the control group.

CONCLUSION

The results of the present trial indicate that, with residual bone height of 2-6 mm and residual crest thickness ≥4 mm, sinus lift surgery with or without biomaterials followed by implant restoration, produces similar clinical and histological outcomes.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Assessment of absorbable gelatin sponge for maxillary sinus floor elevation versus anorganic bovine bone minerals: a randomized clinical trial

PURPOSE

The present study compared the absorbable gelatin sponge as a space-filling material versus anorganic bone bovine mineral (ABBM) in maxillary sinus augmentation with simultaneous endosseous dental implant placement.

METHODS

Eighteen maxillary sinus floor elevation cases were randomly allocated into two groups. The first group received ABBM, while the second group received an absorbable gelatin sponge as a space-filling material. For both groups, CBCT scans were obtained immediately postoperatively and six months later to calculate the difference in sinus floor bone gain. Osstell readings were recorded both at the time of implant placement and implant exposure with a total of twenty-three dental implant placements in relation to the eighteen elevated sinus floors.

RESULTS

The mean radiographic sinus floor gain in the ABBM group was 10.2 mm (± 2.5), while in the absorbable gelatin sponge group was 5.4 mm (± 2.0), with a mean difference of 4.8, which was statistically significant (p < 0.001). The mean implant stability for the ABBM was 77.3 (± 4.9), while in the absorbable gelatin sponge group was 74.2 (± 3.0), with a mean difference of 3.1, which was statistically insignificant (p = 0.1610).

CONCLUSION

The ABBM showed superior results regarding the amount of radiographic sinus floor bone gain. However, the implant stability was invariable between both groups.

Early tissue and healing responses after maxillary sinus augmentation using horizontal platelet rich fibrin bone blocks

BACKGROUND

The effects of horizontal platelet-rich fibrin (H-PRF) bone block on the healing and immune response during sinus augmentation have not been fully investigated histologically at early time points.

METHODS

Eighteenth male New Zealand white rabbits underwent bilateral sinus augmentation and were divided into two groups: deproteinized bovine bone mineral (DBBM) alone and H-PRF + DBBM (H-PRF bone block) group. Maxilla samples were collected at 3, 7 and 14 days post sinus augmentation procedures and analyzed using histological staining for the number of inflammatory cells, new blood vessels and evidence for early osteoclast bone turnover/remodeling. Furthermore, the effects of H-PRF bone blocks on the migration of osteoblasts and THP-1 macrophages were evaluated using a Transwell assay in vitro.

RESULTS

A higher number of immune cells were found in the H-PRF bone block group at 3 and 7 days post-surgery when compared to the DBBM alone group,most notably in the regions close to the mucosal lining and bone plates. Furthermore, a significantly greater number of new blood vessel formations and early signs of osteoclast development were found in the H-PRF bone block group at 14 days. The in vitro transwell assay further confirmed that culture medium from H-PRF bone block markedly promote the migration of osteoblasts and THP-1 macrophages.

CONCLUSIONS

The findings from this study have shown that H-PRF bone block is capable of increasing early immune cell infiltration leading to the acceleration of neovascularization and speeding the process of bone metabolism in vivo following maxillary sinus grafting with DBBM.

Advances and Prospects in Materials for Craniofacial Bone Reconstruction

The craniofacial region is composed of 23 bones, which provide crucial function in keeping the normal position of brain and eyeballs, aesthetics of the craniofacial complex, facial movements, and visual function. Given the complex geometry and architecture, craniofacial bone defects not only affect the normal craniofacial structure but also may result in severe craniofacial dysfunction. Therefore, the exploration of rapid, precise, and effective reconstruction of craniofacial bone defects is urgent. Recently, developments in advanced bone tissue engineering bring new hope for the ideal reconstruction of the craniofacial bone defects. This report, presenting a first-time comprehensive review of recent advances of biomaterials in craniofacial bone tissue engineering, overviews the modification of traditional biomaterials and development of advanced biomaterials applying to craniofacial reconstruction. Challenges and perspectives of biomaterial development in craniofacial fields are discussed in the end.

Radiographic outcome after maxillary sinus floor augmentation with allogeneic adipose tissue-derived stem cells seeded on deproteinized bovine bone mineral. A randomized controlled experimental study

The objective was to test the hypothesis of no difference in radiographic outcome after maxillary sinus floor augmentation (MSFA) with allogeneic adipose tissue-derived stem cells (ASCs) seeded on deproteinized bovine bone mineral (DBBM) (test) compared with excipient on DBBM (control). Eighteen minipigs were assigned into three groups of six animals and euthanised after one month (T1), two months (T2), and four months (T3), respectively. Each maxillary sinus was randomly allocated to either test or control with an equal volume of graft. Computed tomography scans (CTs) after MSFA (T0) were compared with CTs after euthanasia to evaluate graft volume (GV) changes and bone density (BD) using three-dimensional measurements and Hounsfield units. GV was larger in test compared with control at T1 (P = 0.046), whereas GV was larger in control compared with test at T3 (P = 0.01). BD increased from T0 to T1-T3 (P < 0.001) with both treatments. Higher BD was observed in control compared with test at T3 (P = 0.01), while no significant difference was observed at T1 and T2. Conclusively, the present study demonstrate that allogeneic ASCs seeded on DBBM in conjunction with MSFA seemed not to improve the radiographic outcome compared with excipient on DBBM. However, radiological outcomes need to be supplemented by bone histomorphometry before definitive conclusions can be provided about the beneficial use of allogeneic ASCs seeded on DBBM in conjunction with MSFA compared with DBBM alone.

Clinical Assessment of Biphasic Calcium Phosphate in Granules and Paste Forms in Human Maxillary Sinus Bone Augmentation: A Randomized, Split-Mouth Clinical Trial

The aim of the present study is to compare the biphasic calcium phosphate (BCP) using two different forms-(1) granules and (2) paste-in human maxillary sinus bone reconstruction as a split-mouth study using histomorphometric and immunolabeling for osteocalcin. Ten patients with bilateral maxillary posterior partial edentulism were selected in order to reconstruct bone height. They were divided into two groups: BCPG and BCP-P. After six months of bone healing, biopsies were harvested to assess the new bone formation and immunostaining for osteocalcin. The BCP g group had the following results: mean of bone formation in pristine bone 49.4 ± 21.6%, intermediate 49.4 ± 16.2%, and apical 55.3 ± 21.4%. The group BCP-P had a mean of 41.9 ± 17.3% in the pristine bone region, 37.5 ± 7.8% for intermediate, and 39.0 ± 13.5% for apical. The osteocalcin immunolabeling was high for both groups, demonstrating bone calcification. Thus, the two biomaterials present suitable results for the placement of dental implants.

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

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

Risk factors for sinus membrane perforation during lateral window maxillary sinus floor elevation surgery: A retrospective study

PURPOSE

To analyze the sinus membrane perforation (SMP) rate and its potential risk factors during lateral window maxillary sinus floor elevation (LSFE).

MATERIALS AND METHODS

For patients with LSFEs at Department of Implantology, Stomatology Hospital, School of Medicine, Zhejiang Universitiy during January 2014 to December 2020, patient-related risk factors (age/sex/smoking habit), surgery-related risk factors (operator experiment/number of tooth units/technique of osteotomy/surgical approach), and maxillary sinus-related risk factors (residual bone height/sinus membrane thickness/lateral wall thickness/maxillary sinus contours/presence of septa/blood vessels at the lateral maxillary sinus wall) were compared between perforated and nonperforated sites and were evaluated for their influence affecting SMP.

RESULTS

The study sample comprised 278 LSFE procedures in 278 patients; a total of 47 LSFE procedures (16.91%) presented SMP. Four significant factors were identified: smoking habit (p < 0.001), thin (≤1.5 mm) sinus membrane (p = 0.027), maxillary sinus contours (p < 0.001), and presence of septa (p = 0.001). The SMP rate of irregular, narrow tapered, and tapering sinus contours was significantly higher than that of ovoid and square one (p < 0.05).

CONCLUSION

In general, smoking habit, thin sinus membrane, irregular, narrow tapered, and tapering sinus contours, and presence of septa may increase the risk of SMP during LSFE.

A retrospective preliminary histomorphometric and clinical investigation on sinus augmentation using enzyme-deantigenic, collagen-preserving equine bone granules and plasma rich in growth factors

Background

Enzyme-deantigenic equine bone (EDEB) is a substitute of autogenous bone. Mixing it with plasma rich in growth factors (PRGF) seems a viable option to achieve enhanced bone formation in alveolar bone augmentation surgeries. This retrospective study aims to first report the histomorphometric and clinical outcomes achieved when using the EDEB/PRGF mixture for performing sinus augmentation procedures followed by delayed implant placement.

Materials and methods

Records of 11 patients who underwent 14 sinus augmentation surgeries using EDEB/PRGF followed by delayed implant placement were retrospectively collected and analyzed to assess histomorphometric data concerning newly formed bone (NFB) and residual biomaterial (RB) recorded at implant placement, marginal bone loss (MBL) values of implants placed in the augmented sinuses, and implant and prosthetic success and survival rates.

Results

At 5.6 ± 1.1 months after grafting, NFB and RB were 34.0 ± 9.1% and 11.3 ± 2.2% respectively, and no histologic signs of inflammation or immune reaction were observed in any of the 34 bone biopsies being collected. Further, 86.5 ± 4.3 months after implant placement, MBL was 0.40 ± 0.07 mm. No implant or prosthesis failed, and the implant success and survival rates were 100%

Conclusions

Within the limitations of the present study, grafting EDEB/PRGF for lateral sinus augmentation and delayed implant placement seems to be safe. Compared to published data concerning EDEB alone, results of the present study do not suggest that the EDEB/PRGF combination may provide a histomorphometric or medium-/long-term clinical advantage.

Non-grafted versus grafted sinus lift procedures for implantation in the atrophic maxilla: a systematic review and meta-analysis of randomized controlled trials

The aim of this systematic review and meta-analysis was to critically evaluate the currently existing clinical evidence on the efficacy of graftless maxillary sinus membrane elevation for implantation in the atrophic posterior maxilla. A search protocol without limitations to November 2020 was followed by two independent researchers. Randomized controlled trials using the lateral window approach for graftless sinus membrane elevation were included. Uncontrolled, retrospective, non-comparative studies, case reports, and experimental studies in animals or cadavers were excluded. The search identified 2777 studies. Critical selection by two independent researchers then led to the inclusion of a total of nine studies. A risk of bias assessment was applied using the revised Cochrane risk-of-bias tool for randomized trials. A meta-analysis was conducted for seven studies. Results showed a high overall implant survival rate in both the graftless and bone-grafted sinus lift groups (97.92% and 98.73%, respectively). The graftless sinus lift group showed a significantly lower vertical bone height gain, with a mean difference of -1.73mm (P=0.01), and a significantly lower bone density, with a mean difference of -94.7 HU (P<0.001). The implant stability quotient values did not differ significantly between the test and control groups (P=0.07).

Enamel matrix derivative promotes new bone formation in xenograft assisted maxillary anterior ridge preservation-A randomized controlled clinical trial

OBJECTIVES

To compare the effectiveness of deproteinized bovine bone mineral with 10% collagen alone (DBBMC) or with enamel matrix derivative (DBBMC-EMD) in ridge preservation.

METHODS

42 maxillary anterior teeth were extracted and received either a DBBMC (control) or DBBMC-EMD (test) treatment protocol. CBCT taken before and 4 months after the extraction procedure was used to measure changes in alveolar ridge width (RW), buccal bone height (BH) and palatal bone height (PH). Bone cores were harvested during implant osteotomy preparation, and the samples processed histomorphometrically to assess the fraction of new bone (%NB), residual graft (%RG) and soft tissue matrix (%STM).

RESULTS

Overall, both treatment groups showed significant reductions in mean RW from baseline to 4 months after extraction, but no significant change in either mean BH or PH over this time. When CBCT measurements were analysed according to the initial thickness of the buccal wall (BT < 1 mm vs. BT ≥ 1 mm), significant reductions in all ridge dimensions (RW, BH and PH) were noted in the <1 mm BT group. Histomorphometrically, the DBBMC-EMD test group showed significantly increased new bone formation (%NB): (control = 16.5 ± 6.9% cf.; test = 45.1 ± 8.8%) with less residual graft (%RG): (control = 36.8 ± 8.8% cf.; test = 20.3 ± 7.2%) compared to the DBBMC control group.

CONCLUSIONS

Both DBBMC alone and DBBMC-EMD treated sites 4 months after extraction lost RW but showed no significant change in BH or PH. Irrespective of treatment, maxillary anterior teeth with thick initial buccal walls (≥1 mm) exhibited less alveolar ridge reduction 4 months after treatment. The addition of EMD to DBBMC resulted in more new bone formation in the test group.

Xeno-Hybrid Bone Graft Releasing Biomimetic Proteins Promotes Osteogenic Differentiation of hMSCs

Bone defect is a noteworthy health problem and is the second most transplanted tissue after blood. Numerous bone grafts are designed and applied in clinics. Limitations, however, from different aspects still exist, including limited supply, mechanical strength, and bioactivity. In this study, two biomimetic peptides (P2 and P6) are incorporated into a composite bioactive xeno hybrid bone graft named SmartBonePep®, with the aim to increase the bioactivity of the bone graft. The results, which include cytotoxicity, proliferation rate, confocal microscopy, gene expression, and protein qualification, successfully prove that the SmartBonePep® has multi-modal biological effects on human mesenchymal stem cells from bone marrow. The effective physical entrapment of P6 into a composite xeno-hybrid bone graft, withstanding manufacturing processes including exposure to strong organic solvents and ethylene oxide sterilization, increases the osteogenic potential of the stem cells as well as cell attachment and proliferation. P2 and P6 both show a strong biological potential and may be future candidates for enhancing the clinical performance of bone grafts.

Maxillary Sinus Floor Elevation Surgery With BioOss Mixed With Enamel Matrix Derivative: A Human Randomized Controlled Clinical and Histologic Study

Xenograft bone substitutes are commonly used to increase bone volume and height in the deficient posterior maxilla. The addition of enamel matrix derivate (Emdogain) could increase the efficiency of the bone healing process. The aim of this prospective randomized, controlled split-mouth design study was to compare the percentage of newly formed bone in sinus floor augmentation with deproteinized bovine bone mineral with or without the addition of enamel matrix derivative after 6 months of healing. Sixteen bilateral sinus floor augmentation procedures were performed. Deproteinized bovine bone mineral combined with enamel matrix derivative (test) and deproteinized bovine bone mineral alone (control) groups were randomly allocated within each patient. Six months after augmentation and concurrent to implant placement, bone biopsies were taken for histomorphometric analysis. Additionally, implant survival and peri-implant bone levels were radiographically assessed at baseline and 24 months after functional loading. Histomorphometric analysis revealed a significantly higher amount of newly formed bone in the test group compared with the control group (22.6% and 15.5%, respectively; P = .033). No significant differences in the amount of remaining graft or connective tissue was found. Enamel matrix derivative added to deproteinized bovine bone mineral particles significantly increased new bone formation in sinus lift procedures in edentulous or partially edentulous patients with deficient bilateral posterior alveolar ridges requiring augmentation for implant placement.

Maxillary sinus lift response to platelet-rich plasma associated with autogenous bone, ceramic biphasic HA/β-TCP (70:30), or deproteinized bovine bone

BACKGROUND

This study evaluated the long-term effects of platelet-rich plasma (PRP) on bone formation and regeneration when associated with autogenous bone graft (AB), porous biphasic calcium phosphate (pBCP), or deproteinized bovine bone (DBB) in maxillary sinus augmentation (MSA) of rabbit.

METHODS

In 54 rabbits, bilateral MSA procedure was performed and randomly one sinus was filled with 200 mm³ material plus blood clot (AB/clot, DBB/clot, and pBCP/clot) and other with the same graft plus PRP (AB/PRP, DBB/PRP, and pBCP/PRP). After 30, 60, and 180 days, microtomographic were performed to analyze the three-dimensional MSA volume and histomorphometric analyses for the percentage of bone and soft tissues ingrowth. Data were compared by two-way ANOVA and the means were compared by the Tukey test, at p < 0.05.

RESULTS

The percentage of pBCP and DBB were nearly unchanged throughout the whole period and bone formation occurred in the spaces between particles. The MSA volume filled with DBB and pBCP agglutinated with clot and PRP maintained constant during all experimental periods (147.2 mm³ and 154.9 mm³, respectively, p = 0.7377), and no significant changes in the new formatted bone and soft tissue were observed between treatments. In AB/clot and AB/PRP, the MSA volume was similar at 30 days (140.3 mm³ and 137.9 mm³, respectively), but a higher and gradual reduction was observed until 180 days. In the AB/PRP, this reduction was significantly higher (44.2%) than AB/clot (22.5%) (p = 0.01792). Histologically, the addition of PRP to AB accelerated the new bone formation/remodeling maintaining the percentage of new bone similar to AB/clot during all experimental volume (p = 0.6406), while the AB particles showed a higher resorption in AB/PRP than AB/clot until 60 days (mean of 7.8% and 15.1%, respectively, p = 0.0396).

CONCLUSION

The association of PRP with the autogenous graft accelerates the process of bone formation/remodeling in MSA, but not had influence on the pBCP and DBB groups.

Assessment of bone quality using buccal and palatal autogenous cortical shells harvested from two different mandibular donor sites for maxillary alveolar ridge augmentation: a histomorphometric randomized clinical trial

PURPOSE

This study aims to compare the quality of free autogenous bone grafts harvested from two different mandibular donor sites, used as onlay shells to augment horizontally and vertically deficient anterior maxillary alveolar ridges.

METHODS

Fourteen patients with edentulous and atrophic anterior maxillae are randomly allocated into two groups. Seven symphyseal chin (group I) and seven retromolar (group II) mandibular bone grafts were harvested and fashioned to construct buccal and palatal frameworks, fixed in place with mini-screws, followed by compacting the inter-positional gaps with an equal particulate mix of xenograft and autogenous cancellous particulates. Six months later, 42 core biopsies, three from each patient, 21 for each study group, were retrieved before the implants' insertion and subjected to histomorphometric bone area percent analysis.

RESULTS

The bone area percent of the newly formed bone augmented with the chin shells was 52.53 ± 1.68% versus 47.97 ± 1.83% for the retromolar grafts. The mean area percent difference between both groups was statistically significant (p = 0.0004).

CONCLUSION

A higher bone quality and more volumetric stability were associated with the symphyseal cortical shells.

CLINICAL TRIAL REGISTRATION

The study was registered on www.clinicaltrials.gov (#: NCT03607006) in July 2018 by Ola Alaa El Morsy.

Comparison of two anorganic bovine bone in maxillary sinus lift: a split-mouth study with clinical, radiographical, and histomorphometrical analysis

Background

Anorganic bovine bone (Bio-Oss®) has been extensively used for reconstruction of posterior area of maxilla in sinus lift procedure; however, a new graft material (Lumina-Bone Porous®), that has a different manufacturing process, has not been yet compared in clinical and histological terms. The manufacturing process of bovine bone graft is related to size and porosity of the particles, and this can change osteoconductive property of the material and bone formation. The use of Lumina-Porus® could improve bone formation, reduce the remaining particles of the biomaterial using a low-cost material. The aim of this research was to compare the clinical, radiological, and histomorphometrical results from maxillary sinus lift with two different anorganic bovine bone substitutes Bio-Oss® (control) and Lumina-Bone Porous® (test).

Results

A split-mouth study was performed with 13 volunteers. The mean bone ridge height in the deepest portion of maxillary sinuses floor was 3.11 ± 0.83 mm in the Bio-Oss® and 2.38 ± 0.75 mm in the Lumina-Bone Porous®. After sinus lift, the Bio-Oss® group shows bone ridge height of 11.56 ± 2.03 mm and Lumina-Bone® of 10.62 ± 1.93 mm. The increase in alveolar bone height scores was significant between pre-augmentation and 6 months after SL in both groups (p < 0.001). No statistical significant difference in newly formed bone in the Bio-Oss® group (20.4 ± 5.4%), and Lumina-Bone Porous® (22.8 ± 8.5%) was histomorphological observed (p > 0.05). On the other hand, the residual graft particles showed significant difference between the Bio-Oss® group (19.9 ± 8.6%) and Lumina-Bone Porous® (14.6 ± 5.6%) (p < 0.05). The survival rate of dental implants for augmented area with Lumina Bone Porous® was 88.88%, while for Bio-Oss® group was 100%.

Conclusion

Both materials Bio-Oss® and Lumina-Bone Porous® can be used in the maxillary sinus floor augmentation with good predictability in clinical, radiographical, and histological point of view.

Effect of Simvastatin on Bone Regeneration: A Histologic and Histomorphometric Analysis

PURPOSE

The purpose of the present study was to evaluate the efficacy of simvastatin administration as an osteoinductive agent combined with bovine bone material (BBM) for augmentation of human maxillary sinuses.

MATERIALS AND METHODS

In the present randomized clinical trial with a split-mouth design, 24 maxillary sinuses in 12 patients were augmented using BBM alone or BBM combined with simvastatin. Biopsy samples were taken 9 months after maxillary sinus floor augmentation for histologic and histomorphometric analyses. A total of 44 implants were placed in the augmented bone.

RESULTS

The results of the microscopic assessment of most samples revealed no inflammation or only mild chronic inflammation. Lamellation was detectable in old bone trabeculae under polarized light microscopy but was not observed in newly formed bone. Osteocytes were found with a lower frequency in the lacunae of newly formed bone compared with normal bone. No significant differences were found in the amount of newly formed bone and the amount of residual particles between the 2 groups.

CONCLUSIONS

Despite the greater mean percentage of newly formed bone in the test group, the histomorphometric analysis results did not show a significant positive effect for the use of simvastatin in maxillary sinus augmentation.

Treatment of peri-implant soft tissue defects: a narrative review

Soft tissue defects around dental implants, such as papilla or volume loss, peri-implant recession and alterations of the ridge color and/or texture, lead to esthetic and functional complaints. Treatments of these defects in implants are more demanding than in teeth because peri-implant tissue exhibits different anatomical and histological characteristics. This narrative review discusses the proposed treatments for soft tissue defects around implants in the current literature. Several clinical and pre-clinical studies addressed methods to augment the quantity of the peri-implant keratinized mucosa. Autogenous grafts performed better than soft tissue substitutes in the treatment of soft tissue defects, but there is no clinical consensus on the more appropriate donor area for connective tissue grafts. Treatment for facial volume loss, alterations on the mucosa color or texture and shallow peri-implant recessions are more predictable than deep recessions and sites that present loss of papilla. Correction of peri-implant soft tissue defects may be challenging, especially in areas that exhibit larger defects and interproximal loss. Therefore, the regeneration of soft and hard tissues during implant treatment is important to prevent the occurrence of these alterations.

Impact of Inorganic Xenograft on Bone Healing and Osseointegration: An Experimental Study in Rabbits

PURPOSE

To evaluate if an inorganic graft applied before implant insertion interferes with osseointegration.

MATERIALS AND METHODS

The bilateral mandibular incisors of 12 rabbits were extracted. One of the sockets was randomly filled with an inorganic xenogenic bone graft, whereas the remaining socket was allowed to heal naturally and served as a control. After 60 days, titanium implants were inserted into healing areas. The animals were killed 60 days after. Bone depositions were marked with fluorochrome oxytetracycline, alizarin, and calcein and evaluated using confocal laser scanning microscopy. Bone-to-implant contact (BIC) and bone area (BA) within the limits of the implant threads were analyzed. Data were compared statically by paired t tests, one-way ANOVA, and Bonferroni post hoc tests (α = 0.05).

RESULTS

No differences between the control and experimental groups in bone deposition for each marker, in either the BIC or BA analysis were observed. The bone deposition marked by alizarin (14-21 days) was the highest, followed by oxytetracycline (0 and 7 days) and calcein (45 and 52 days) in both groups (P < 0.05).

CONCLUSION

The bone healing or the course of osseointegration was not impaired by the use of an inorganic xenogenic graft before insertion of a titanium implant.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Histopathological comparison of healing after maxillary sinus augmentation using xenograft mixed with autogenous bone versus allograft mixed with autogenous bone

OBJECTIVE

To compare the clinical and histologic outcomes of two different grafting materials (allograft and xenograft) when combined with autogenous bone and covered with a collagen membrane for sinus augmentation.

MATERIAL AND METHODS

A parallel case series of fourteen patients in need of a unilateral sinus augmentation was evaluated in this study. Seven patients received a graft composed by autologous cortical bone (ACB) and anorganic bovine bone in a ratio of 1:1; the other seven patients received ACB mixed with an allograft in the same ratio. Bone biopsies were obtained 6 months after sinus augmentation at the time of implant placement. Comparative histomorphometrical, histopathological, and immunohistochemical analyses were conducted and statistically analyzed.

RESULTS

After 12 months of functional loading, all implants in both groups were clinical and radiographically successful. Histomorphometrically, although the initial bone formation was not significantly different between groups (new mineralized tissue: 41.03(12.87)% vs. 34.50(13.18)%, p = .620; allograft vs. xenograft groups), the graft resorbed faster in the allograft group (remnant graft particles: 9.83[7.77]% vs. 21.71[17.88]%; p = .026; allograft vs. xenograft groups). Non-mineralized tissue did not statistically differ either (49.00[14.32]% vs. 43.79[19.90]%; p = .710; allograft vs. xenograft groups). The histologic analyses revealed higher cellular content, four times more osteoid lines, and higher vascularization in the xenograft group. Musashi-1 (mesenchymal stromal cell marker) was also more intensively expressed in the xenograft group (p = .019).

CONCLUSIONS

Both composite grafts generate adequate substratum to receive dental implants after healing. Compared with the xenograft composite, allograft composite shows faster turnover and a quicker decrease in biological action after 6 months.

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.

Maxillary sinus augmentation with leukocyte and platelet-rich fibrin and deproteinized bovine bone mineral: A split-mouth histological and histomorphometric study

OBJECTIVES

To evaluate the effect of leukocyte and platelet-rich fibrin (L-PRF) in combination with deproteinized bovine bone mineral (DBBM) on bone regeneration in maxillary sinus augmentation.

MATERIAL AND METHODS

Thirteen patients (nine males and four females, mean age ± SD; 49.92 ± 10.37) were enrolled to the study. 26 maxillary sinus augmentation procedures were randomly performed using DBBM and L-PRF mixture (test) or DBBM alone (control) in a split-mouth design. The same surgical procedures were performed in both groups, and bone biopsies were harvested from the implant sites 6 months postoperatively for histological and histomorphometric evaluations as the primary outcome of the study. Implants were placed and then loaded in the augmented sites after 6 months. The secondary outcomes included clinical and radiographic data and were obtained pre- and postoperatively.

RESULTS

There was no qualitative difference in histological analyses among the groups. In all samples, a newly formed bone was in direct contact with the residual material. The percentages of newly formed bone (test; 21.38 ± 8.78% and control; 21.25 ± 5.59%), residual bone graft (test; 25.95 ± 9.54% and control; 32.79 ± 5.89%), bone graft in contact with the newly formed bone (test; 47.33 ± 12.33% and control; 54.04 ± 8.36%), and soft tissue (test; 52.67 ± 12.53% and control; 45.96 ± 8.36%) were similar among the groups (p < .05). Similar radiographic bone height in the augmented area was observed, and implant survival rate was 100% for both groups.

CONCLUSIONS

Both techniques were effective for maxillary sinus augmentation, and after 6 months of healing, the addition of L-PRF in DBBM did not improve the amount of regenerated bone or the amount of the graft integrated into the newly formed bone under histological and histomorphometric evaluation.

Comparison of Different Periodontal Healing of Critical Size Noncontained and Contained Intrabony Defects in Beagles

BACKGROUND

Regenerative techniques help promote the formation of new attachment and bone filling in periodontal defects. However, the dimensions of intraosseous defects are a key determinant of periodontal regeneration outcomes. In this study, we evaluated the efficacy of use of anorganic bovine bone (ABB) graft in combination with collagen membrane (CM), to facilitate healing of noncontained (1-wall) and contained (3-wall) critical size periodontal defects.

METHODS

The study began on March 2013, and was completed on May 2014. One-wall (7 mm × 4 mm) and 3-wall (5 mm × 4 mm) intrabony periodontal defects were surgically created bilaterally in the mandibular third premolars and first molars in eight beagles. The defects were treated with ABB in combination with CM (ABB + CM group) or open flap debridement (OFD group). The animals were euthanized at 8-week postsurgery for histological analysis. Two independent Student's t-tests (1-wall [ABB + CM] vs. 1-wall [OFD] and 3-wall [ABB + CM] vs. 3-wall [OFD]) were used to assess between-group differences.

RESULTS

The mean new bone height in both 1- and 3-wall intrabony defects in the ABB + CM group was significantly greater than that in the OFD group (1-wall: 4.99 ± 0.70 mm vs. 3.01 ± 0.37 mm, P < 0.05; 3-wall: 3.11 ± 0.59 mm vs. 2.08 ± 0.24 mm, P < 0.05). The mean new cementum in 1-wall intrabony defects in the ABB + CM group was significantly greater than that in their counterparts in the OFD group (5.08 ± 0.68 mm vs. 1.16 ± 0.38 mm; P < 0.05). Likewise, only the 1-wall intrabony defect model showed a significant difference with respect to junctional epithelium between ABB + CM and OFD groups (0.67 ± 0.23 mm vs. 1.12 ± 0.28 mm, P < 0.05).

CONCLUSIONS

One-wall intrabony defects treated with ABB and CM did not show less periodontal regeneration than that in 3-wall intrabony defect. The noncontained 1-wall intrabony defect might be a more discriminative defect model for further research into periodontal regeneration.

Effect of Porous Titanium Granules on Bone Regeneration and Primary Stability in Maxillary Sinus: A Human Clinical, Histomorphometric, and Microcomputed Tomography Analyses

The aim of this randomized controlled study was to comparatively analyze the new bone (NB), residual bone, and graft-bone association in bone biopsies retrieved from augmented maxillary sinus sites by histomorphometry and microcomputed tomography (MicroCT) in a split-mouth model to test the efficacy of porous titanium granules (PTG) in maxillary sinus augmentation. Fifteen patients were included in the study and each patient was treated with bilateral sinus augmentation procedure using xenograft (equine origine, granule size 1000-2000 μm) and xenograft (1 g) + PTG (granule size 700-1000 μm, pore size >50 μm) (1 g), respectively. After a mean of 8.4 months, 30 bone biopsies were retrieved from the implant sites for three-dimensional MicroCT and two-dimensional histomorphometric analyses. Bone volume and vital NB percentages were calculated. Immediate after core biopsy, implants having standard dimensions were placed and implant stability quotient values were recorded at baseline and 3 months follow-up. There were no significant differences between groups according to residual bone height, residual bone width, implant dimensions, and implant stability quotient values (baseline and 3 months). According to MicroCT and two-dimensional histomorphometric analyses, the volume of newly formed bone was 57.05% and 52.67%, and 56.5% and 55.08% for xenograft + PTG and xenograft groups, respectively. No statistically significant differences found between groups according to NB percentages and higher Hounsfield unit values were found for xenograft + PTG group. The findings of the current study supports that PTG, which is a porous, permanent nonresorbable bone substitute, may have a beneficial osteoconductive effect on mechanical strength of NB in augmented maxillary sinus.

Implant stability after sinus floor augmentation with deproteinized bovine bone mineral particles of different sizes: a prospective, randomized and controlled split-mouth clinical trial

The aim of this study was to compare implant stability after maxillary sinus floor augmentation using small- or large-sized particles of Bio-Oss. Ten partially edentulous patients requiring bilateral maxillary sinus floor augmentation were enrolled. The subjects were assigned randomly to one of two experimental groups: maxillary sinus was filled with 0.25-1mm particle size (small particles) and the contralateral side was filled with 1-2mm particle size (large particles). After 8 months, a total of 25 implants were placed in the two maxillary sinuses. Primary implant stability was measured immediately after implant placement (T0) using a torque controller and resonance frequency analysis (RFA). Six months after implant placement (T1), the implant stability was measured again. There were no postoperative complications in either particle size group, and the success rate for implant survival was 100%. All implants showed good primary stability as evidenced by high torque for the implant insertion in both groups. RFA revealed high ISQ values for all implants installed in both groups at T0 and T1. These results indicate that the size of the Bio-Oss particles (small and large) did not influence implant stability in the maxillary sinus. Indeed, small and large particles of Bio-Oss presented optimal properties, supporting their possible use as osteoconductive grafts.

The improved biological response of shark tooth bioapatites in a comparative in vitro study with synthetic and bovine bone grafts

Autologous bone is considered to be the gold standard for bone tissue regeneration, providing more highly efficient functional responses compared to synthetic materials, and avoiding the rejection risks of allogenic grafts. However, it presents limitations for certain types of surgery due to its high resorption levels and donor site morbidity. Different biphasic synthetic composites, based onnon-apatitic calcium phosphates enriched with apatitic phases-such as hydroxyapatite, and bioderived bone grafts of bovine and porcine origin-are proposed as lower resorption materials due to their higher crystalline structure. The present work proposes two new sources of bioapatites for bone filler applications obtained from the dentine and enameloid of shark teeth, respectively. These bioapatites each present a characteristic apatite-based composition and additional enrichments of specific trace elements, such as magnesium and fluorine, with proven roles in bone metabolism. Their processing and physicochemical characterization (SEM, FT-Raman and XRD) is presented, together with an in vitro evaluation of osteogenic activity compared to a commercial bovine mineralized matrix and synthetic HA/β TCP grafts. The results proved the globular morphology (0.5-1.5 μm) and porosity (~50 μm and ~0.5-1 μm) of shark dentine bioapatites with biphasic composition: apatitic (hydroxyapatite and apatite-(CaF)), non-apatitic (whitlockite), and an apatitic phase (fluorapatite), organized in oriented crystals in enameloid bioapatites. An evaluation of the pre-osteoblast MC3T3-E1 morphology revealed the colonization of pores in dentine bioapatites and an aligned cell growth in the oriented enameloid crystals. A higher proliferation (p  <  0.01) was detected at up to 21 d in both the shark bioapatites and synthetic biphasic graft with respect to the bovine mineralized matrix. Finally, the great potential of porous biphasic dentine bioapatites enriched with Mg and the aligned fluorapatite crystals of enameloid bioapatites in promoting greater osteogenic activity was confirmed with a significantly increased ALP synthesis (p  <  0.01) compared to the commercial grafts.

Peri-implant defect regeneration in the diabetic pig: A preclinical study

OBJECTIVES

The study aims to establish a peri-implant dehiscence-type bone defect in a diabetic animal model of human bone repair and to quantify the influence of diabetes on peri-implant bone regeneration.

MATERIAL AND METHODS

Experimental diabetes was induced in three domestic pigs by streptozotocin. Three animals served as healthy controls. After 12 months four standardized peri-implant dehiscence bone defects were surgically created in the ramus mandibulae. The animals were sacrificed after 90 days. Samples were histologically analyzed to quantify new bone height (NBH), bone-to-implant-contact (BIC), area of newly formed bone (NFB), bone-density (BD), and bone mineralization (BM) in the prepared defect (-D) and in a local control region (-L).

RESULTS

After 90 days, diabetic animals revealed a significantly lower BIC (p = 0.037) and BD (p = 0.041) in the defect area (-D). NBH and BM-D differences within the groups were not significant (p > 0.05). Significant more NFB was measured in the healthy control group (p = 0.046). In the region of local bone BIC-L was significant less in the diabetic group (p = 0.028). In the local control region BD-L and BM-L was lower in the diabetic group compared to the healthy control animals (p > 0.05).

CONCLUSION

Histological evidence indicates impaired peri-implant defect regeneration in a diabetic animal model.

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.

Management of anticoagulated patients in implant therapy: a clinical comparative study

OBJECTIVES

This prospective clinical comparative study aimed to analyze the postoperative bleeding risk of patients continuing their anticoagulation therapy (AT) and undergoing implant surgery and bone grafting procedures.

MATERIALS AND METHODS

The treatments ranged from the insertion of single or multiple dental implants over implant exposures to sinus floor augmentation and vertical and/or lateral bone grafting with autologous bone grafts. The patients of the test groups (AT groups) were treated with platelet aggregation inhibitors (PAIs), Vitamin-K inhibitors, Vitamin-K inhibitor withdrawal bridged with heparin (LMWH), or new/direct oral anticoagulants (NOACs/DOACs). Patients of the control group were non-anticoagulated (non-AT group). Surgical procedures were performed in the same manner in all groups. Pre, intra, and postoperative data concerning the treatment, extent of the surgery and bleedings was recorded and statistically evaluated.

RESULTS

There were seven postoperative bleedings in 564 patients (1.2%), four in the AT groups (3.4%), and three in the non-AT group (0.6%). No thromboembolic complication occurred in the whole observation period. The invasiveness of the surgical procedure had no statistically significant effect on bleeding frequencies. Patients taking Vitamin-K inhibitors had a significantly higher risk of a postoperative bleeding compared to patients without any AT (P = 0.038). Two patients were hospitalized due to the severity of the bleeding as a precautionary measure (one in the non-AT and one in the PAI group). All bleedings were easily controllable with local hemostatic measures. There was no postoperative bleeding recorded for patients taking DOACs.

CONCLUSIONS

Anticoagulation therapy should be continued in patients undergoing implant surgery and bone grafting procedures avoiding thromboembolic complications. Surgeons should always apply the most minimally invasive approach to reduce postoperative risks and be able to apply local hemostatic measures in terms of a bleeding complication.

A histomorphometric assessment of collagen-stabilized anorganic bovine bone mineral in maxillary sinus augmentation - a prospective clinical trial

OBJECTIVE

To histomorphometrically compare the use of collagen-stabilized anorganic bovine bone (ABBM-C) (test) to anorganic bovine bone + autogenous bone (ABBM + AB) (control) in maxillary sinus augmentation.

MATERIALS AND METHODS

Forty (n = 40 sinuses) patients underwent sinus augmentation and received either control (20 sinuses) or test bone graft (20 sinuses). Bone samples were harvested from the augmented sinuses 5 months postgrafting. The samples were processed for histomorphometry, which assessed within the primary region of interest (ROI-1), the area fraction of new bone (%NB), graft particle osseointegration (% OI), residual graft (%RG), and soft tissue components (% STM). The same analysis was also carried out in a second region of interest (ROI-2) located in a zone 1 mm proximal to the previous maxillary sinus floor.

RESULTS

In both ROI-1 and ROI-2, the mean % NB, %RG, and %STM in the control group were similar to mean values in the test group. The % OI was significantly greater in the control group (42.0 +/- 26.8) when compared to the test group (19.6 +/- 27.3) in ROI-2 (P < 0.05). No statistically significant differences were seen when ROI-1 and ROI-2 were compared except for improved %OI in ROI-2 in the control group. The mean proportion of lamellar bone to woven bone in the control group (1.22 ± 1.48) was significantly greater than the test group (0.38 ± 0.29) (P < 0.05).

CONCLUSION

ABBM-C exhibited very similar histomorphometric parameters to the composite graft of ABBM + AB. The ABBM + AB group was more mature as indicated by the significantly greater proportion of lamellar bone when compared to the ABBM-C. Improved % OI was seen in the zone proximal to the resident bony floor in the ABBM + AB group. Based on histological assessment, ABBM-C is a suitable bone substitute for the purposes of maxillary sinus augmentation. Its clinical utility may be indicated in cases of sinus membrane perforation and insufficient autogenous bone in the local area.

Histological and Histomorphometric Human Results of HA-Beta-TCP 30/70 Compared to Three Different Biomaterials in Maxillary Sinus Augmentation at 6 Months: A Preliminary Report

OBJECTIVE

The aim of this investigation was to examine the bone regenerative potential of newly biphasic calcium phosphate ceramics (HA-β-TCP 30/70), by assessing histological and histomorphometric results of human specimens retrieved from sinuses augmented with HA-β-TCP 30/70, and comparing them to anorganic bovine bone (ABB), mineralized solvent-dehydrated bone allograft (MSDBA), and equine bone (EB), after a healing period of 6 months.

MATERIALS AND METHODS

Four consecutive patients with edentulous atrophic posterior maxilla were included in this report. A two-stage procedure was carried out for sinus augmentation with HA-β-TCP 30/70, ABB, MSDBA, and EB. After 6 months, specimens were retrieved at the time of implant placement and processed for histological and histomorphometric analyses.

RESULTS

At histological examination, all biomaterials were in close contact with the newly formed bone and showed the same pattern of bone formation; the grafted granules were surrounded by a bridge-like network of newly formed bone. A limited number of ABB particles were partially covered by connective tissue. The histomorphometric analysis revealed 30.2% newly formed bone for Ha-β-TCP 30/70, 20.1% for ABB, 16.4% for MSDBA, and 21.9% for EB.

CONCLUSIONS

Within the limitations of the present investigation, these results support the successful use of HA-β-TCP 30/70 for sinus augmentation.

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.

Efficacy of rhBMP-2/Hydroxyapatite on Sinus Floor Augmentation

The aim of this randomized single-blinded active-controlled clinical study was to evaluate the early efficacy of low-dose Escherichia coli–derived recombinant human bone morphogenetic protein 2 (rhBMP-2) soaked with hydroxyapatite granules (BMP-2/H) as compared with an inorganic bovine bone xenograft (ABX) in maxillary sinus floor augmentation. In a total of 127 subjects who were enrolled at 6 centers, maxillary sinus floors were augmented with 1 mg/mL of rhBMP-2 (0.5 to 2.0 mg per sinus) and BMP-2/H (0.5 to 2.0 g; n = 65) or with ABX alone (0.5 to 2.0 g; n = 62). Core biopsies were obtained 3 mo after the augmentation surgery and were analyzed histomorphometrically. The mean new bone formation with BMP-2/H and ABX augmentation was 16.10% ± 10.52% and 8.25% ± 9.47%, respectively. The BMP-2/H group was noninferior to the ABX group; the lower limit of the 1-sided 97.5% confidence interval for the difference between the 2 groups was calculated as 4.33%, which was greater than the prespecified noninferiority margin of −3.75%. An additional test with the Wilcoxon rank-sum test with a 2-sided 5% significance level showed that bone formation between the 2 groups was significantly different ( P < 0.0001). The soft tissue and residual graft areas showed no significant differences between the groups. With regard to safety, no significant difference between the 2 groups was observed; there was no significant increase in the amount of rhBMP-2 antibody in the serum after BMP-2/H grafting. Our study suggested that low-dose Escherichia coli–derived rhBMP-2 with hydroxyapatite was effective in early stages for enhanced bone formation after maxillary sinus floor augmentation without harmful adverse events ( Clinicaltrials.gov NCT01634308).

A histomorphometric assessment of collagen-stabilized anorganic bovine bone mineral in maxillary sinus augmentation - a randomized controlled trial in sheep

OBJECTIVE

To histomorphometrically compare the use of collagen-stabilized anorganic bovine bone (ABBM-C) (test) to anorganic bovine bone + autogenous bone (ABBM + AB) (control) in maxillary sinus augmentation.

MATERIALS AND METHODS

Nine sheep underwent bilateral sinus augmentation. Each sinus was randomized to receive either control or test bone graft. Three animals were sacrificed at 8 weeks, and six animals were sacrificed at 16 weeks post-grafting. The 18 sinuses were processed for histomorphometry, which assessed the area fraction of new bone (%NB), residual graft (%RG) and soft tissue components (% STM), as well as graft particle osseointegration (% OI), within three zones equally distributed from the augmented sinus floor.

RESULTS

At week 16, a significant increase in %NB was evident across all three zones in the control group when compared to week 8. A significantly greater %NB was evident in the control group when compared to the test group in zones 2 (P < 0.001) and 3 (P < 0.001). There was a significant increase in %OI in week 16 when compared to week 8 across all three zones in the control group (P < 0.001). %OI in the control group was significantly greater across all three zones when compared to the test group at week 16 (P < 0.001). Zone was found to be a significant main effect (P < 0.001) that was independent of time and treatment with decreasing %OI in distant zones. %RG did not significantly change with time for both groups. There was a significant reduction in %ST in week 16 when compared to week 8 across all three zones in the control group (P < 0.001). %ST in the test group was significantly greater across all zones when compared to the control group at week 16 (P < 0.001).

CONCLUSION

Both groups exhibited very similar histomorphometric measurements in the zones proximal to the resident sinus wall. The % NB and % OI were greatest in the zones proximal to resident bony walls and gradually decreased as the distance from the proximal walls increased. There was greater % NB and % OI in the control group when compared to the test group in the distant zone.