Assessment of the value of anorganic bone additives in sinus floor augmentation: a review of clinical reports

A randomized clinical trial of phycogenic materials for sinus grafting with hydroxyapatite versus biphasic calcium phosphate: 2 years clinical outcomes

OBJECTIVES

To assess in a prospective randomized trial two phycogenic bone substitutes-biphasic calcium phosphate (BCP) versus almost pure hydroxyapatite (HA)-for their volume stability and clinical implications after sinus floor elevation (SFE).

MATERIALS AND METHODS

Twenty patients requiring lateral-window SFE 6 months prior to implant surgery were randomized to a BCP or HA group. As primary outcome, the grafts were analyzed for volume stability, using four cone-beam computed tomography scans obtained immediately/6/12/24 months after SFE. Secondary outcomes were implant survivval, success, periotest values, oral-health-related quality of life (OHIP-G14), and pain (VAS).

RESULTS

Kolmogorov-Smirnov goodness-of-fit test revealed normal distribution of samples (p = .200). At 6/12/24 months, the augmented volumes decreased to 96/92/90% (HA) or 99/96/96% (BCP). Volume changes were significantly a factor of time (p < .001; generalized linear model with repeated measures) and reached significantly lower values in HA group (p = .018). Significant intergroup difference in volume losses was notable at 24 months (p = .021; t-test for independent samples). Periotest values decreased from -3/-4.1 (HA/BCP) after implant placement to -6.3/-4.5 (HA/BCP) after 6 months. OHIP scores diverged at 2 months (HA: 9.5; BCP: 5.2) and largely resolved by 24 months (HA: 1.3; BCP: 1.9). VAS scores were comparable, 2.2 at 1 week after SFE being their highest mean level.

CONCLUSIONS

After 2 years, both groups experienced no biological or technical complications, demonstrating a consistent healing trajectory without notable symptoms. Although no significant differences were observed in implant stability and survival, BCP demonstrated higher volume stability than HA.

Combined Effect of Platelet-Rich Fibrin Matrix (PRFM) and Demineralized Freeze-Dried Bone Allograft (DFDBA) in Immediate Implant Placement: A Single-Arm Clinical Trial

Introduction

Placement of immediate implants in contrast to delayed implant placement may be favorable. The factors contributing to this are shortened overall treatment time, aid in ideal orientation and fixture placement, bone preservation following extraction, and achieving optimal aesthetics involving soft tissue. However, the gap distance between the surface of the implant and the buccal bony wall during implant placement is critical for subsequent bone healing in a fresh extraction socket. Considering that as the gap broadens, the amount of bone-to-implant contact (BIC) decreases, causing an apical shift of the highest bone-implant contact. Incorporating a bone substitute material (BSM) within the fixture-socket gap preserves alveolar ridge volume by minimizing socket remodeling and encouraging de-novo bone formation.

Aim and objectives

To evaluate the efficacy of platelet-rich fibrin matrix (PRFM) and demineralized freeze-dried bone allograft (DFDBA) in fresh extraction socket with simultaneous implant placement.

Methods

Implants were immediately placed in 12 patients following a two-stage submerged protocol. The combination of PRFM and DFDBA was used to fill the gap between the implant body and the surrounding socket wall. The final restoration was placed after 3 months following implant placement. The full mouth plaque, gingival bleeding index, and gingival esthetics scores were assessed at baseline, 3, and 6 months. The crestal changes were evaluated using intraoral periapical radiographs (IOPA) at baseline, 3, and 6 months. Cone beam computed tomography (CBCT) images were obtained at baseline and 6 months after implant loading to analyze the buccolingual changes.

Results

At 6 months follow-up, the coronal bone remodeling detected on CBCT revealed a minimal (0.1 mm) narrowing of the alveolar ridge in a buccolingual direction, with a mean bone loss of 0.10+0.09, which was statistically non-significant (p > 0.05). Implant success was 100% at 6 months after loading as determined by Akbrektsson’s criteria for implant success.

Conclusions

The adjunctive use of PRFM with DFDBA following immediate implant placement yielded a significant reduction in bone resorption and maintenance of buccolingual dimensions.

Radiographic and Histomorphometric Evaluation of Sinus Floor Augmentation Using Biomimetic Octacalcium Phosphate Alloplasts: A Prospective Pilot Study

This prospective single-arm clinical study aimed to radiographically and histomorphometrically evaluate the efficacy of the lateral approach for sinus floor elevation (LSFE) using biomimetic octacalcium phosphate (OCP) synthetic bone graft (Bontree^®). LSFE using Bontree^® was performed on 10 patients (15 implant placement sites) willing to undergo implant surgery, followed by implant placements after 6 months of the healing period. The vertical bone height (VBH) and Hounsfield unit (HU) values at each implant placement site were evaluated radiographically using cone-beam computed tomography at baseline immediately after surgery (T1) and 6 months after surgery (T2). A histomorphometric evaluation of the bone core biopsy specimen was also performed. The mean VBH and HU changes at all sites included a decrease by 0.91 mm and a statistically significant increase by 431.86, respectively, from T1 to T2. The mean ratio of the newly formed bone (23.34% ± 10.63%) was greater than that of the residual bone graft (19.09% ± 8.74%), indicating that Bontree^® is effective for new bone formation. This pilot study suggests that Bontree^® is a promising bone substitute for LSFE.

Comparison of the vertical bone defect healing abilities of carbonate apatite, β-tricalcium phosphate, hydroxyapatite and bovine-derived heterogeneous bone

The treatment of vertical bone defects caused by severe periodontal disease requires the regeneration of periodontal tissue. Although various bone substitutes have been clinically applied to vertical bone defect correction, the evaluation of these materials in periodontal tissue remains incomplete. The purpose of this study was to examine the bone regeneration abilities of various bone substitutes including Cytrans, Cerasorb, Neobone and Bio-Oss in a 3-wall bone defect animal model. All of these bone substitutes showed a similar healing ability to periodontal ligament and cementum. However, Cytrans showed the fastest bone healing ability compared with the other materials at 4 weeks post-transplantation. In addition, the recruitment of osteoclasts and endothelial cells was observed in Cytrans grafts at 4 weeks, but only detected at 8 weeks in the other materials. These results suggest that Cytrans promotes faster bone healing by inducing bone remodeling and angiogenesis.

Biphasic calcium phosphate and polymer-coated bovine bone matrix for sinus grafting in an animal model

Autogenous bone grafting requires a donor site and may lose substantial volume during remodeling. Several bone replacement materials (BRMs) are under development to overcome these limitations, especially for indications for minimally intervention surgeries. The objective of our study was to assess the potential of an equine collagen cone reinforced with biphasic calcium phosphate (CC-BCP) particles and deproteinized bovine bone matrix (BBM) coated with polylactic acid, and poly-ε-caprolactone copolymer (BBM-PCC) and then to compare the outcomes with a deproteinized BBM and an equine CC without a filler in a sheep sinus grafting model in the Elleven female sheep were selected. Two experimental sites on each side of the animals were prepared using an extraoral approach for maxillary sinus wall. The four treatments were performed in each animal through a standardized 10-mm access window. While the BBM access was covered with a collagen membrane, all other sites were closed with an equine collagen membrane. All animals were euthanized after 16 weeks. New bone (NB), residual graft particles, and connective tissue were measured in undemineralized resin-embedded sections. As a result, one sheep did not survive the surgery. All sites in the remaining 10 sheep healed uneventfully. All CC and BBM-PCC grafts resorbed and failed to augment the sinuses. BBM and CC-BCP, in contrast, showed some histologic evidence of NB and surgical site augmentation. The NB fraction in the latter two groups accounted for 10 ± 9 and 4 ± 5%, respectively (p > 0.05). In conclusion, BBM-PCC and collagen cone performed poorly for sinus floor augmentation, while deproteinised BBM and reinforced collagen cone demonstrated comparable outcomes.

Bioactive-glass in periodontal surgery and implant dentistry

Bioactive-glass (B-G) is a material known for its favorable biological response when in contact with surrounding fibro-osseous tissues, due not only to an osteoconductive property, but also to an osteostimulatory capacity, and superior biocompatibility for use in human body. The objectives of this paper are to review recent studies on B-G in periodontal and implant therapy, describing its basic properties and mechanism of activity as well as discoursing about state of art and future perspective of utilization. From a demonstrated clinical benefit as bone graft for the elimination of osseous defects due to periodontal disease (intrabony/furcation defects) and surgeries (alveolar ridge preservation, maxillary sinus augmentation), to a potential use for manufacturing bioactive dental implants, possibly allowing wider case selection criteria together with improved integration rates even in the more challenging osteoporotic and medically compromised patients, this biomaterial represents an important field of study with high academic, clinical and industrial importance.

Histomorphometric analysis of maxillary sinus augmentation with calcium phosphate nanocrystal-coated xenograft

OBJECTIVE

The purpose of this study was to evaluate the histomorphometric result from maxillary sinus augmentation with calcium phosphate nanocrystal-coated bovine bone (Biocera).

STUDY DESIGN

Maxillary sinus augmentations were performed on 10 patients with the delayed placement of implants. The lateral bony window was created using a piezoelectric saw, and the sinus membrane was elevated to make a new compartment. Biocera was grafted. The bony window was repositioned over the bone graft. In all cases, samples were taken for biopsy at the time of implant placement, 6 to 8 months after the grafting procedure.

RESULTS

None of the 10 patients had complications, and there were no clinical and radiographic signs of infection. Histomorphometrically, 25.94% (± 11.24%) of newly formed bone, 52.67% (± 12.60%) of soft tissue, and 21.38% (± 10.76%) of residual grafts were shown. Histologic findings showed newly formed bone surrounding the residual grafted particles, without inflammation. Newly formed bone along inner surface of the repositioned bony window area showed more mature and dense bone structure than new bone formed along bone graft.

CONCLUSION

The present study revealed that calcium phosphate nanocystal-coated xenograft was considered to be a suitable bone graft material for maxillary sinus augmentation.

Maxillary sinus floor augmentation and dental implant placement using dentin matrix protein-1 gene-modified bone marrow stromal cells mixed with deproteinized boving bone: A comparative study in beagles

OBJECTIVE

The aim of the study was to evaluate the effects of the combined use of dentin matrix protein-1 (DMP1) gene-modified bone marrow stromal cells (BMSCs) and Bio-Oss(®) for maxillary sinus floor augmentation (MSFA) implant placement in dogs.

MATERIALS AND METHODS

BMSCs were derived from bone marrow of six beagles and cultured. The cells were transduced with a lentiviral vector overexpressing the DMP1 gene and enhanced green fluorescent protein (EGFP) gene (Lenti-DMP1/EGFP) in test group, and with a lentiviral vector encoding EGFP gene (Lenti-EGFP) in control group. Six dogs received sinus augmentations using the bilateral approach with a simultaneous implant placement at each site respectively. At the same concentration, 2×10(7) cells/ml, one sinus was grafted using a mixture of autologous DMP1/EGFP gene-modified BMSCs and Bio-Oss(®) (DMP1 group), and the contralateral sinus was grafted with autologous EGFP gene-modified bMSCs and Bio-Oss(®) (EGFP group). After a 3 month healing period, bone regeneration and osseointegration were evaluated using histologic and histomorphometric methods.

RESULTS

The bone-implant contact (BIC) and the bone area fraction in the DMP1 group (BIC: 34.67%±8.23%, bone area fraction: 35.16%±3.32%) were significantly greater compared with the EGFP group (BIC: 26.06%±5.16%, bone area fraction: 20.74%±1.63%) (P<0.05). No significant difference between the residual bone substitute material volume (BSMV) in the DMP1 group (35.86±7.35) and the EGFP group (32.16±9.16) was found in our study (P>0.05).

CONCLUSION

BMSCs modified with the DMP1 gene can be used as an adjunct to Bio-Oss(®) to enhance new bone formation and the osseointegration of dental implants in MSFA of dogs.

Radiographic evaluation of regenerated bone following poly(lactic-co-glycolic) acid/hydroxyapatite and deproteinized bovine bone graft in sinus lifting

Although numerous biomaterials are used for maxillary sinus-lift surgery, the ideal material for such procedures has not yet been identified. Both heterologous and alloplastic bone substitutes have a solely osteoconductive effect and lack the osteoinductive properties of the bone morphogenetic proteins typical of autologous bone. Our group assessed a new alloplastic graft material, poly(lactic-co-glycolic) acid/hydroxyapatite (PLGA/HA), implanted in a human model of maxillary sinus-lift surgery. For this prospective, random, double-blind trial, we used deproteinized bovine bone (DBB) as the comparison material. Radiographic bone vertical height and density were assessed at approximately 28 weeks after grafting using cone-beam computed tomography. The vertical dimension of the regenerated bone was equivalent between the 2 groups. The density of the bone regenerated using PLGA/HA was significantly lower than that obtained with DBB. Despite clinical assessments demonstrating that PLGA/HA has sufficient characteristics for use in sinus-lift surgery, DBB provided greater bone density and an equivalent vertical dimension of grafted bone. Further studies are needed to supplement the radiologic findings with histologic and micromorphometric examinations.

Bone regeneration of macropore octacalcium phosphate-coated deproteinized bovine bone materials in sinus augmentation: a prospective pilot study

OBJECTIVE

To investigate the osteogenic potential of macropore octacalcium phosphate (OCP)-coated deproteinized bovine bone materials (DBBMs) in sinus augmentation.

STUDY DESIGN

Macropore OCP-coated DBBM was manufactured from bovine bone by thermal and chemical processing. Sinus grafts of a lateral window approach with experimental bone were conducted in 10 patients. At 6 months after surgery, a total of 10 specimens were obtained from 10 patients. But, 4 of them were excluded because the amount of specimens was not enough for evaluation. Morphological investigation under scanning electron microscopy and histological evaluation were performed.

RESULTS

OCP was evenly attached to the surface of the experimental graft and showed a relatively large pore size (300-400 μm) compared with Bio-Oss (100-200 μm). New bone comprised 23.49% (± 0.10), and residual graft material comprised 15.39% (± 0.06) in bone specimens.

CONCLUSION

A macropore-sized design and OCP coating could present a favorable environment for new bone formation in maxillary sinus grafts.

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

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

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

OBJECTIVES

This investigation focused on histological characteristics and 5-year implant survival after sinus floor augmentation with anorganic bovine bone (ABB, Bio-Oss) and ABB plus autologous bone (AB) with a ratio of 1/1.

MATERIAL AND METHODS

Nineteen consecutive patients with bony atrophy of the posterior edentulous maxilla and a vertical bone height ≤4 mm were prospectively included in this study. In the first surgical stage, the maxillary sinus was non-randomized either augmented with ABB alone (n = 12) or a 1/1 mixture of ABB and AB (n = 7). After a mean healing period of 167 days, biopsies were harvested in the region of the grafted sinus with a trephine burr and implants were placed simultaneously, ABB n = 18 and ABB + AB n = 12. The samples were microradiographically and histomorphometrically analyzed judging the newly formed bone (bone volume, BV), residual bone substitute material volume (BSMV), and intertrabecular volume (soft tissue volume, ITV) in the region of the augmented maxillary sinus. Implant survival was retrospectively evaluated from patient's records.

RESULTS

No significant difference in residual bone substitute material (BSMV) in the ABB group (31.21 ± 7.74%) and the group with the mixture of ABB and AB (28.41 ± 8.43%) was histomorphologically determined. Concerning the de novo bone formation, also both groups showed statistically insignificant outcomes; ABB 26.02 ± 5.23% and ABB + AB 27.50 ± 6.31%. In all cases, implants were installed in the augmented sites with sufficient primary stability. After a mean time in function of 5 years and 2 months, implant survival was 93.75% in the ABB and 92.86% in the ABB + AB group with no statistically significant differences.

CONCLUSION

The usage of ABB plus AB to a 1/1 ratio leads to an amount of newly formed bone comparable with the solitary use of ABB after grafting of the maxillary sinus. Considering that ABB is a non-resorbable bone substitute, it can be hypothesized that this leads to stable bone over time and long-term implant success. Importantly, in the sole use of ABB, bone grafting and therefore donor site morbidities can be avoided.

Gene expression and morphometric parameters of human bone biopsies after maxillary sinus floor elevation with autologous bone combined with Bio-Oss® or BoneCeramic®

OBJECTIVES

Although the clinical success of Bio-Oss(®) and BoneCeramic(®) has been corroborated by histologic and histomorphometric findings, the biological events that occur during healing after maxillary sinus floor elevation (MSFE) are unknown. Here, we evaluated biopsies of grafted bone with a mixture of autologous bone and Bio-Oss(®) or BoneCeramic(®) after two different healing time periods to understand the molecular process underlying bone formation after MSFE.

MATERIAL AND METHODS

Seven patients, following a bilateral split-mouth design model and needing a MSFE to allow implant placement, were recruited for this study. Right or left sinuses were grafted with autologous maxillary bone combined either with Bio-Oss(®) or BoneCeramic(®) , respectively. Twenty biopsies were taken at the time of implant insertion after 4-5 months or 6-8 months of MSFE, and analyzed by micro-computed tomography (microCT) and gene-expression analysis.

RESULTS

MicroCT analysis revealed no differences in the morphometric parameters or BMD either after 4-5 months or 6-8 months of MSFE between Bio-Oss(®) and BoneCeramic(®) . At molecular level, a higher expression of bone forming gene Runx2 was observed after 4-5 months of MSFE in the Bio-Oss(®) compared with the BoneCeramic(®) group.

CONCLUSIONS

Our results indicate that differences found at the molecular level between Bio-Oss(®) and BoneCeramic(®) are not translated to important differences in the 3D microstructure and BMD of the grafted bone.

Effect of deproteinized bovine bone matrix coverage on the resorption of iliac cortico-spongeous bone grafts - a prospective study of two cohorts

OBJECTIVES

The augmentation of the alveolar ridge using iliac cortico-spongeous bone grafts is routinely used. However, bone grafts show a substantial degree of resorption, which may negatively affect the long-term success of dental implants in the augmented area. The aim of this study was to evaluate the effect of a deproteinized bovine bone matrix coverage on the resorption of iliac bone grafts.

MATERIAL AND METHODS

Two cohorts consisting of 40 patients who received a vertical augmentation of the alveolar ridge with onlay grafts from the iliac crest were prospectively investigated over a period of 2 years. In half of the patients (n = 40), the grafts were covered by a thin layer of deproteinized bovine bone matrix (DBBM cohort). The other 40 patients received the identical surgical procedure without a DBBM coverage (non-DBBM cohort). The graft height/resorption was radiographically determined immediately after surgery, 6 months, 1 year, and 2 years postoperatively.

RESULTS

The height of the bone graft 6 months after surgery accounted 92.15% of the initial value in the DBBM cohort and 87.76% in the non-DBBM cohort. One year after augmentation, the height reduced to 83.95% in the DBBM cohort and 72.92% in the non-DBBM cohort. Two years after surgery, the resorption slowed down and the height of the grafts accounted 81.27% in the DBBM cohort and 71.43% in the non-DBBM cohort. The difference was statistically significant.

CONCLUSION

Deproteinized bovine bone matrix reduces the postoperative resorption of iliac bone block grafts and may therefore enhance the long-term implant prognosis in the augmented area.

Bio-Oss®acts on Stem cells derived from Peripheral Blood

OBJECTIVES

This study aims to study how Bio-Oss® can induce osteoblast differentiation in mesenchymal stem cells, the expression levels of bone related genes and mesenchymal stem cells markers using real time Reverse Transcription-Polymerase Chain Reaction.

METHODS

PB-hMSCs stem preparations were obtained for gradient centrifugation from peripheral blood of healthy anonymous volunteers, using the Acuspin System-Histopaque 1077. The samples were then cultured for 7 days for RNA processing, and the expression was quantified using real time PCR.

RESULTS

Bio-Oss® caused an induction of osteoblast transcriptional factor like RUNX2 and of bone related genes; SPP1 and FOSL1. In contrast, the expression of ENG was significantly decreased in stem cells treated with Bio-Oss® with respect to untreated cells, indicating the differentiation effect of this biomaterial on stem cells.

CONCLUSION

The results obtained can be relevant to enhance the understanding of the molecular mechanism of bone regeneration and can act as a model for comparing other materials with similar clinical effects.

Histological results after maxillary sinus augmentation with Straumann® BoneCeramic, Bio-Oss®, Puros®, and autologous bone. A randomized controlled clinical trial

OBJECTIVE

This investigation focused on a comparison of clinical and histological characteristics after sinus floor augmentation with biphasic calcium phosphate (BCP, Straumann BoneCeramic(®) ), anorganic bovine bone (ABB, Geistlich Bio-Oss(®) ), mineralized cancellous bone allograft (MCBA, Zimmer Puros(®) ), or autologous bone (AB).

MATERIALS AND METHODS

Thirty consecutive patients with a posterior edentulous maxillary situation and a vertical bone height less than or equal to 4 mm were included in this study. A two-stage procedure was carried out. After augmentation of the maxillary sinus with ABB, BCP, MCBA, or AB followed by a healing period of 5 months, biopsies were taken with simultaneous implant placement. The samples were analyzed using microradiography and histology.

RESULTS

Ninety-four implants were placed in the augmented positions and 53 bone biopsies were taken and evaluated. The bone volume fraction of newly formed bone was measured as 30.28 ± 2.16% for BCP, 24.9 ± 5.67% for ABB, 41.74 ± 2.1% for AB, and 35.41 ± 2.78% for MCBA with significant increases in bone volume of AB vs. BCP and ABB, and MCBA vs. ABB samples. Significantly different residual bone substitute material was measured as 15.8 ± 2.1% in the BCP group and 21.36 ± 4.83% in the ABB group.

CONCLUSION

As it provides the highest rate of de novo bone formation, AB can be considered to remain the gold standard in sinus floor augmentation. All tested control materials showed comparable results and are suitable for maxillary sinus augmentation.

The effect of bovine bone graft with or without platelet-rich plasma on maxillary sinus floor augmentation

PURPOSE

The purpose of this study was to compare Unilab Surgibone (USB) (Mississauga, Ontario, Canada), a bone xenograft (bovine), with platelet-rich plasma (PRP) and USB without PRP to augment the human maxillary sinus in preparation to receive dental implants.

PATIENTS AND METHODS

Patients who had bilateral pneumatized maxillary sinuses were included. Sinuses on one side were augmented with the USB-PRP combination and formed the study group, whereas the opposite-side sinuses were augmented with USB alone and served as controls. Bone biopsy specimens were taken during implant placement at 6.8 ± 0.9 months after maxillary sinus floor augmentation. Resonance frequency analysis measurements were performed at implant placement (first control) and before the prosthetic stage (second control), at 6.5 ± 0.7 months after implant surgery.

RESULTS

There were 10 patients (7 men and 3 women; mean age, 53.7 ± 0.8 years). Integration between new bone and residual grafts was histologically observed in all samples. The volumes of soft tissue were 59.9% ± 7.5% and 57.8% ± 4.4% in the control and study groups, respectively; residual graft, 21.9% ± 6.6% and 23.6% ± 5.9%, respectively; new bone, 15.8% ± 4.8% and 16.0% ± 3.8%, respectively; and trabecular bone, 64.7% ± 22.5% and 69.1% ± 18.6%, respectively. A positive correlation was found between new bone volume and trabecular bone volume (P = .0001). The mean Implant Stability Quotient (ISQ) values were 71.7 ± 4.9 and 70.3 ± 5.7 in the control and study groups, respectively, at first control and 75.4 ± 6.4 and 74.4 ± 6.4, respectively, at second control. The mean ISQ values at second control in both groups were significantly higher than at first control (P = .043 and P = .028, respectively). No statistically significant differences were observed between groups (P > .05).

CONCLUSION

The combination of USB and PRP does not have any effect on new bone formation and implant stabilization.

Maxillary sinus floor elevation and grafting with deproteinized bovine bone mineral: a clinical and histomorphometric study

OBJECTIVES

This study evaluated the histomorphometric and clinical outcomes of maxillary sinus floor elevation using deproteinized bovine bone mineral (DBBM).

MATERIAL AND METHODS

Maxillary sinuses with a residual vertical height of <5 mm were augmented with DBBM alone before implant placement 9 months later. At the time of implant surgery, trephine samples were removed and histological and histomorphometric analyses were performed to examine the percentage of bone and residual graft using point counting and software-aided analysis. Patients were recalled for clinical and radiographic examination up to 3 years later.

RESULTS

Twenty-five patient specimens were analysed. The percentages of regenerated bone and residual graft material were 19% and 40%, respectively. Software-aided analysis was comparable to point counting. Twelve patients attended for clinical follow-up. Implants placed into this regenerated bone exhibited success and survival rates of 100% after an average follow-up of 3 years. The average vertical height gained was 7.9 mm.

CONCLUSIONS

The use of DBBM alone in maxillary sinus floor elevation is a predictable method to gain vertical bone height in the posterior maxilla.

Sinus graft with safescraper: 5-year results

PURPOSE

In the procedure of sinus floor elevation, autogenous bone, allogenic grafts, and several other bone substitutes are used. However, autogenous bone is still considered the gold standard. Donor sites for autogenous bone are generally the iliac crest, oral cavity, calvarium bone, and tibia. In this work the experience with the use of a Safescraper device for harvesting of autogenous bone is reported and a decision-making algorithm for grafting in sinus floor elevation procedures is proposed.

MATERIALS AND METHODS

Forty sinus augmentation procedures were performed in 34 patients. All sinuses were filled with a mixture of autogenous bone and bovine hydroxyapatite. A Safescraper device was used to harvest autologous bone from the maxillary area. Platelet-rich plasma was used to sustain bone placement. Sixty-five dental implants were placed at 4 months with a flapless procedure. A clinical and radiological 5-year retrospective case series of a cohort is reported.

RESULTS

In all cases new bone formation was confirmed radiologically and implant placement was performed successfully. Analysis of samples obtained by biopsy with histology and microcomputed tomography showed the presence of mature bone. Healing problems were observed in only 1 case.

CONCLUSIONS

Sinus augmentation with bone grafts obtained from oral cavity with a bone scraper device has the advantage of providing autogenous bone without the need for an extra surgical approach. This procedure yields satisfactory results in bone formation, implant survival, and patient satisfaction. When combined with a flapless approach for implant placement, a decrease in the morbidity of the entire process is achieved.

A meta-analysis of histomorphometric results and graft healing time of various biomaterials compared to autologous bone used as sinus floor augmentation material in humans

BACKGROUND

To date, no studies have been published in which histomorphometric data from a large group of patients comparing various biomaterials for sinus floor augmentation procedures were evaluated.

MATERIALS AND METHODS

A meta-analysis of the English literature from January 1993 till April 2009 was carried out. Out of 147 titles, according to our criteria, 64 articles were selected for analysis describing the use of autologous bone and their alternatives, such as allogenic, xenogenic, and alloplastic materials.

RESULTS

On the basis of autologous bone grafting, a reference value for total bone volume (TBV) of 63% was found. Particulation of the bone graft resulted in a general reduction of −18% in TBV. Delayed implant placement reduced the TBV with −7%. Overall TBV was 8% or 6% higher if a biopsy was, respectively, taken before 4.5 months or after 9.0 months after initial sinus augmentation surgery. Allogenic, xenogenic, alloplastic, or combinations of graft materials all resulted in a significant lower amount of TBV compared to autologous bone grafting ranging from −7% to −26%. Inventorying the effect of "biopsy time" for autologous bone, the TBV was significantly higher before 4.5 and after 9.0 months of healing time compared to period in between. Surprisingly, no significant differences in TBV with respect to "biopsy time" for bone substitutes were found.

CONCLUSIONS

On the basis of the aspect of TBV autologous bone still has to be considered to be the gold standard in sinus augmentation surgery. However, the consequence of the TBV for implant survival is still unraveled yet.

Sinus floor augmentation surgery using autologous bone grafts from various donor sites: a meta-analysis of the total bone volume

BACKGROUND

To date, no studies have been published that evaluated histomorphometric data from a large number of patients while comparing different sites and methods of autologous bone grafting in sinus floor augmentation procedures. A meta-analysis of the English literature from January 1995 till April 2009 was carried out.

MATERIALS AND METHODS

PubMed search engine and the following journals were explored: Clinical Oral Implant Research, International Journal of Oral and Maxillofacial Implants, International Journal of Periodontics and Restorative Dentistry, and the Journal of Periodontology.

RESULTS

Out of 147 titles, according to our criteria, 25 articles were left for analysis. The majority were prospective controlled studies (21) and 2 randomized clinical trials, 1 pilot study and 1 case series. A reference value of 47% for total bone volume (TBV) was found while using iliac bone grafting as a standard. Use of intraoral bone grafts increases the TBV, with 11% for chin bone and 14% for bone grafted from other intraoral sites. Particulation of the bone graft has a negative effect on the TBV of 18%. Surprisingly, no correlation between TBV and the time of graft healing was found. Histological section thickness seemed to be a significant variable, as every micron increase of section thickness leads to an increase of 0.4% of TBV.

CONCLUSIONS

Bone grafting from the iliac crest resulted in a significantly lower TBV compared with intraoral bone grafting. However, due to the limited availability of intraoral bone to be harvested, iliac grafts still have to be considered the gold standard in augmenting the severely atrophic maxilla.

Radiologic evaluation of putty versus powder form of demineralized bone matrix in sinus floor elevation

The aim of this study was to evaluate differences in ossification of the 2 forms of demineralized bone matrix (DBM)-putty and powder-radiographically, using digital densitometry on panoramic radiographs in maxillary sinus floor augmentation procedures. Twelve subjects needing bilateral maxillary sinus floor augmentation for the placement of osseointegrated implants were included in this study. The left and right maxillary sinuses were augmented in the same session in each patient using the 2 preferred forms of DBM-putty and powder-during the same session. One sinus was augmented with DBM putty form and the other sinus was augmented with DBM powder form randomly. Every patient had a total of 4 panoramic radiographs taken, preoperatively and in the first, third, and sixth month postoperatively. The densitometry measurements were taken from each step of the aluminium step-wedge, from both sinuses from different points a total of 3 times, and the average of these measurements was calculated. The amount of mineralization in each graft material in every radiograph was clarified by the appearance of a difference in the equivalent aluminium thickness, and the obtained results were statistically evaluated. The results showed that there were no significant differences between two graft materials statistically. These two graft materials could be good alternatives in sinus lifting procedures because of less morbidity, lower price, and good ossification. The results indicate that 2 different types of DBM achieved good ossification in the sinus lifting procedure, and there is not a considerable distinction in these 2 forms.

Evaluation of the Long-Term Results of Rat Cranial Bone Repair Using a Particular Xenograft

Bone defects that cannot be healed completely are termed critical-sized defects and can be used to test bone grafts for medicine, dentistry, and periodontology. The aim of the present study was to detect the effects of a xenograft (Unilab Surgibone) on bone building in experimentally created parietal bone defects in rats. Standardized parietal bone defects were created in 16 rats, and each defect had a circular morphology 6 mm in diameter. The right defect sites were filled with porous particle material, and the left site was used as control. After the 3rd, 6th, and 12th months, rats were killed and tissue samples obtained from the related site of the cranium. Subsequently, histological sections were taken and stained with different stains for evaluation under light microscope. The rate of bone formation was assessed using a semiquantitative method. These results showed that dense collagenous tissue was observed in the control area during the third month, whereas xenograft particles were surrounded by a fibrous tissue layer at the implantation site. Osteoclast-like cells were also observed. There was also no significant bone repair at other observation periods. It can be concluded that the material used had no evidence of resorption and does not enhance bone formation. However, it seems biocompatible, osteoconductive, and could be used in a limited manner as a material for filling osseous defects in clinical practice.

Simulation of sinus floor augmentation with symphysis bone graft using three-dimensional computerized tomography

The objective of this study was to evaluate the maximum amount of harvestable bone graft in the mandibular symphysis and the augmentation volume needed for different sinus lift levels (from 10 to 18 mm), in addition to calculating which sinus lift level can be acquired using the individual's symphysis bone graft volume with three-dimensional computerized tomography (3D CT) and software. Data from 15 CT scans was obtained from 15 adult patients (10 males, five females). The CT data, in DICOM format, was read into Mimics software from Materialize (Leuven, Belgium), with a slice thickness of 0.5 mm. The mandibular symphysis bone graft volumes and different levels of sinus lift augmentation volumes were calculated on the 3D images using Mimics software. It was determined that the average symphysis bone volume (3491.08+/-772.12 mm(3)) could provide approximately 14 mm of sinus lift height (3167.84+/-1067.65). 3D CT techniques and software can be used to calculate the required graft volume for sinus floor augmentation and symphysis bone graft volume, and the mandibular symphysis region can provide adequate bone volume for sinus lift augmentation.

A Novel Ultra-porous Titanium Dioxide Ceramic with Excellent Biocompatibility

The current study compares biocompatibility, cell growth and morphology, pore diameter distribution, and interconnectivity of a novel titanium dioxide (TiO2) bone graft substitute granules with three different commercially available bone graft granules Natix®, Straumann® BoneCeramic, and Bio-Oss®. Human primary mesenchymal stem cells were cultured on the bone graft substitutes and cell viability and proliferation were evaluated after 1 and 3 days. The microstructural properties of the bone graft substitutes were evaluated by scanning electron microscopy, micro-computed tomography analysis, and mechanical testing. The cell viability and proliferation, porosity, interconnectivity, open pore size, and surface area-to-volume ratio of TiO2 granules were significantly higher than commercial bone granules (Bio-Oss® and Straumann ® BoneCeramic).

Histomorphometric analysis of human maxillary sinus lift with a new bone substitute biocomposite: a preliminary report

PURPOSE

To analyze radiographic and histological outcomes of maxillary sinus floor augmentation using a calcium-sulfate based allograft containing demineralized bone matrix particles.

MATERIALS AND METHODS

Fifteen maxillary sinus lift procedures with simultaneous placement of titanium implants were performed in 12 patients of both genders aged 36-71 years. Each sinus cavity was filled by the biocomposite. After 3 months of healing, all surgical sites were uncovered and bone biopsies were retrieved for undecalcified histology and histomorphometry. The ratio between the original and the grafted sinus height (GSH/OSH) was computed using a panoramic radiography taken immediately after surgery and at 3 months of healing, and the two ratios were compared by Wilcoxon signed-rank test.

RESULTS

By 3 months, all implants were stable without clinical and radiographic signs of infection. Significant changes in GSH/OSH during healing were seen (2.7 +/- 0.6 initially vs. 2.6 +/- 0.5 after healing; p = 0.01). Histologic findings showed newly formed bone surrounding the residual grafted particles without inflammation. At 3 months, mean regenerated bone density was 33.8 +/- 8.6%; marrow spaces amounted to 32.3 +/- 10.3%; residual graft was 33.9 +/- 9.0%. Similar histomorphometric and radiographic results were obtained independently from patient age or sex.

CONCLUSIONS

The analysed putty seems to be a safe and effective graft material for maxillary sinus floor augmentation by accelerating bone regeneration and thus reducing the healing time.

Anorganic bovine bone and a silicate-based synthetic bone activate different microRNAs

Bio-Oss (BO), composed of anorganic bovine bone, is widely used in several bone regeneration procedures in oral surgery. PerioGlas (PG) is an alloplastic material that has been used for grafting of periodontal osseous defects since the 1990s. However, how these biomaterials alter osteoblast activity to promote bone formation is poorly understood. We attempted to address this question by using microRNA microarray techniques to investigate differences in translational regulation in osteoblasts exposed to BO and PG. By using miRNA microarrays containing 329 probes designed from human miRNA sequences, we investigated miRNAs whose expression was significantly modified in an osteoblast-like cell line (MG-63) cultured with BO vs PG. Three up-regulated miRNAs (mir-337, mir-200b, mir-377) and 4 down-regulated miRNAs (mir-130a, mir-214, mir-27a, mir-93) were identified. Our results indicated that BO and PG act on different miRNAs. Globally, PG causes activation of bone-forming signaling, whereas BO also activates cartilage-related pathways.

VEGF and MVD expression in sinus augmentation with autologous bone and several graft materials

OBJECTIVE

The aim of this study was to assess vascular endothelial growth factor (VEGF) expression and microvessel density (MVD) in maxillary sinus augmentation with autogenous bone and different graft materials for evaluating their angiogenic potential.

METHODS

Biopsies were harvested 10 months after sinus augmentation with a combination of autogenous bone and different graft materials: hydroxyapatite (HA, n = 6 patients), demineralized freeze-dried bone allograft (DFDBA, n = 5 patients), calcium phosphate (CP, n = 5 patients), Ricinus communis polymer (n = 5 patients) and control group--autogenous bone only (n = 13 patients).

RESULTS

In all the samples, higher intensities of VEGF expression were prevalent in the newly formed bone, while lower intensities of VEGF expression were predominant in the areas of mature bone. The highest intensity of VEGF expression in the newly formed bone was expressed by HA (P < 0.001) and CP in relation to control (P < 0.01) groups. The lowest intensities of VEGF expression in newly formed bone were shown by DFDBA and polymer groups (P < 0.05). When comparing the different grafting materials, higher MVD were found in the newly formed bone around control, HA and CP (P < 0.001).

CONCLUSION

Various graft materials could be successfully used for sinus floor augmentation; however, the interactions between bone formation and angiogenesis remain to be fully characterized.

Sinus augmentation using human mesenchymal stem cells loaded into a beta-tricalcium phosphate/hydroxyapatite scaffold

OBJECTIVE

Implant placement in the posterior maxilla may often be contraindicated because of insufficient bone volume and presence of the maxillary sinus. In these situations, sinus floor augmentation frequently has been proposed as the best treatment. This clinical study was based on the hypothesis that the clinical effectiveness of adult mesenchymal stem cells (MSCs) loaded to the biphasic scaffold.

METHODS

In this report, the clinical and radiographic results are presented on 6 consecutively treated patients using MSCs in combination with biphasic hydroxyl apatite/ beta-tricalcium phosphate (HA/TCP) for sinus elevation. All the patients in the study had less than 3 mm initial bone height in the posterior maxillary area (IBH). MSCs were cultured and expanded from bone marrow aspirate for each patient. Three months after sinus elevation, radiographic evaluation was performed for the patients and the secondary bone height was measured (SBH(1)). In the second stage surgery, 30 implants were placed. Trephine bur was used as a pilot drill and a core biopsy was obtained from each implant site. Prosthetic rehabilitation of the patients was performed after 4 months. Secondary bone height was measured 9 months after implant placement (SBH(2)).

RESULTS

Of 30 implants, 28 (93%) were considered clinically successful. Two implants were removed due to mobility at the time of surgical exposure. Histologic evaluation of the biopsy specimens revealed numerous areas of osteoid and bone formation HA/TCP, with no evidence of inflammatory cell infiltrate. Mean bone regenerate was 41.34%. Clinically, no complications were observed, and all implants were considered clinically osseointegrated after 4 months. Mean bone height was measured 3 and 12 months after sinus grafting (mean of SBH(1)= 12.08 mm and mean of SBH(2)= 10.08 mm).

CONCLUSIONS

These clinical and histological findings suggest that sinus grafting with HA/TCP in combination with MSCs provide a viable therapeutic alternative for implant placement. The findings suggest that the addition of MSCs to bone derivative/substitute materials may enhance bone formation in the maxillary sinus area. Of course more studies with the control groups are needed for the evaluation of this method as a clinical solution for the patients.