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

Critical-sized marginal defects around implants treated with xenografts in rabbits

BACKGROUND

Healing of critical-size defects is a well-known problem that has been challenged in several studies. The aim of the experiment was to evaluate bone formation and osseointegration of implants installed in critical defects of the mandibular body simultaneously grafted with Bio-Oss® or Cerabone®.

MATERIAL AND METHODS

Defects, 10 mm wide and 3 mm deep, were prepared at both lateral aspects of the mandible in 12 rabbits. One implant was installed in the center of the defect, and bovine xenografts produced either at low (Bio-Oss®; Low-T) or high (Cerabone®; High-T) temperatures were used to fill the defects. A collagen membrane was placed to cover the sites. Healing was evaluated 10 weeks after surgery.

RESULTS

In both groups, most sites showed optimal healing with closure of the coronal entrance of the defects. However, residual defects occupied by soft tissues and biomaterial particles were observed, even though generally limited to some regions of the defect. Osseointegration of the implant surface in the region of the defect was poor in both groups.

CONCLUSIONS

Circumferential marginal critical-size defects around implants filled with bovine xenografts presented regions with a complete healing in both groups. However, the healing was not complete at all regions in most defects; therefore, a complete optimal healing of critical-size marginal defects cannot be predicted.

Histomorphometric evaluation of different graft associations for maxillary sinus elevation in wide antral cavities: a randomized controlled clinical trial

OBJECTIVES

Pneumatization of the maxillary sinus can make it difficult, if not impossible, to install osseointegrated implants, and undertake their eventual functional rehabilitation, which may ultimately require regenerative techniques to achieve. This randomized controlled study proposed conducting a histological evaluation of the behavior of different graft materials in wide maxillary sinuses, at a height of 8 to 10 mm from the alveolar ridge, combined with bone remnants less than 3mm.

MATERIALS AND METHODS

Thirty-six patients underwent a sinus elevation procedure through the lateral window. The sinuses were randomly filled with the following materials (n=12/group): group 1, xenogenic bone + autogenous bone (ratio 70:30, respectively); group 2, xenogenic bone + L-PRF; and group 3, xenogenic bone. At 8 months, bone biopsies of engrafted sites were harvested and analyzed histomorphometrically in order to quantify newly formed bone tissue.

RESULTS

The results showed a greater area of newly formed bone for G1, averaging 2678.37 (1116.40) μm², compared with G2 at 984.87 (784.27) μm², and G3 at 480.66 (384.76) μm² (p < 0.05). Additionally, fewer xenogenic bone particles and a large amount of connective tissue were observed in G2.

CONCLUSIONS

In maxillary sinuses with large antral cavities, autogenous bone combined with xenogenic bone seems to demonstrate better graft remodeling and improve bone formation, compared with the addition of L-PRF.

CLINICAL RELEVANCE

L-PRF produces few advantages regarding new bone formation in the wide maxillary sinuses.

TRIAL REGISTRATION

Brazilian Clinical Trials Registry (REBEC) number RBR-2pbbrvg.

Tissue Level Changes after Maxillary Sinus Floor Elevation with Three Types of Calcium Phosphate Ceramics: A Radiological Study with a 5-Year Follow-Up

This study evaluates the radiological changes in tissue height after maxillary sinus floor elevation (MSFE) using three types of calcium phosphate ceramics over a period of up to 5 years after dental implant placement. In 163 patients, MSFE was performed. Three groups of patients were distinguished and treated based on the type of calcium phosphate ceramic used and radiologically evaluated: 40 patients with β-tricalcium phosphate (β-TCP), 76 patients with biphasic calcium phosphate (BCP) 20% hydroxyapatite (HA)-80% β-TCP, and 47 patients with BCP 60% HA-40% β-TCP. Radiological measurements were performed on panoramic radiographs at several time points up to 5 years after dental implant placement. After MSFE, a slow decrease in tissue height measured over time was seen in all three study groups. Resorption of the grafted bone substitutes was more prominent in β-TCP than in BCP ceramics with an HA component (60/40 and 20/80). Loss of tissue height after 5 years was lowest in BCP 60/40 and highest in β-TCP. This radiological study shows a predictable and comparable behavior of the slow decrease in tissue height over time for all three types of calcium phosphate ceramics used in MSFE. The fraction of HA in calcium phosphate ceramics and dental implant loading seems to be beneficial for tissue height maintenance after MSFE.

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.

Remodelling of sinus bone grafts according to the distance from the native bone: A histomorphometric analysis

OBJECTIVES

To evaluate graft remodelling according to the distance from the native bone in maxillary sinuses grafted with anorganic bovine bone (ABB).

MATERIAL AND METHODS

Bilateral sinus grafting was performed in twenty patients with residual bone height <5 mm before implant placement. After 8 months, biopsy samples were harvested, and histomorphometric analysis was performed to examine bone formation according to the distance (in mm) from the native bone (sinus floor). In the grafted area, the percentages of new bone (NB), residual graft material (rABB), and soft tissue (ST) were evaluated.

RESULTS

A total of 103 biopsy samples were evaluated, and the percentages of NB, rABB, and ST were 31.62 ± 9.85%, 18.94 ± 7.88%, and 49.41 ± 9.52%, respectively, in the 1st mm; 27.15 ± 9.83%, 23.33 ± 9.45%, and 49.53 ± 11.73%, respectively, in the 2nd mm; 23.61 ± 13.02%, 21.35 ± 11.08%, and 55.03 ± 16.14%, respectively, in the 3rd mm; and 21.67 ± 12.29%, 19.67 ± 10.28%, and 58.66 ± 12.46%, respectively, in the 4th mm. The 1st millimetre of the grafted area (closer to the native bone) presented a larger amount of NB than the other portions of the grafted areas and a smaller amount of rABB than the 2nd mm of the grafted area (p < .05). The amount of ST was larger in the 3rd and 4th mm of the grafted area than in the first 2 millimetres (p < .05).

CONCLUSION

The distance from the native bone influences bone formation following maxillary sinus augmentation.

Improvement of bone repair with l-PRF and bovine bone in calvaria of rats. histometric and immunohistochemical study

OBJECTIVES

The effect of leucocyte- and platelet-rich fibrin (L-PRF), associated with DBBM (deproteinized bovine bone mineral; Bio-Oss®) was investigated and compared with autogenous bone graft as a standard material for filling bone defects.

MATERIAL AND METHODS

A defect of 5 mm in diameter was performed in 40 calvaria of rats. The animals were divided into 5 groups and received blood clot (CO), autogenous bone (AUT), DBBM (BIO), L-PRF, or DBBM associated with L-PRF (BIO-LPRF). After 4 and 8 weeks, bone regeneration was assessed by histometric and immunohistochemical analyses.

RESULTS

The highest mean percentage of bone formation found at 4 and 8 weeks was observed for the BIO-L-PRF group (54.0% ± 2.8 and 63.6% ± 2.2). The lowest mean percentage at 4 and 8 weeks was observed for the CO group (16.7% ± 2.5 and 20.5% ± 1.0). There was statistical similarity among the AUT, BIO, and L-PRF groups. The expressions OC, RUNX 2, and VEGF showed a favorable aspect in the formation of new bone for BIO-L-PRF. VEGF was the marker with the highest expression because it was related to the initial healing process, promoting the migration and proliferation of endothelial cells in the region of the defect. Even after weeks, VEGF maintained a moderate expression.

CONCLUSIONS

The association of L-PRF with DBBM improved bone repair when these biomaterials were inserted into the defects of the calvaria of rats.

CLINICAL RELEVANCE

This reinforces the good performance of bovine bone and L-PRF as filler materials, especially when associated.

Short implants (≤8mm) compared to standard length implants (>8mm) in conjunction with maxillary sinus floor augmentation: a systematic review and meta-analysis

The objective was to test the hypothesis of no difference in the treatment outcome after the installation of short implants (≤8mm) in the posterior part of the maxilla compared to standard length implants (>8mm) in conjunction with maxillary sinus floor augmentation (MSFA) using the lateral window technique, after an observation period of ≥3years. A search of the MEDLINE, Embase, and Cochrane Library databases, in combination with a hand-search of relevant journals, was conducted. The search yielded 1102 titles. Finally, three studies that fulfilled the inclusion criteria were included. All were considered to have a low risk of bias. Meta-analyses revealed no significant differences in implant survival or peri-implant marginal bone loss between the two treatment modalities. However, the use of standard length implants in conjunction with MSFA was characterized by a tendency towards more peri-implant marginal bone loss. There was no statistically significant difference between the two treatment modalities with regard to overall patient satisfaction. Short implants seem to be a suitable alternative to standard length implants in conjunction with MSFA. However, further randomized controlled trials with larger patient samples and an observation period of more than 3years are needed before one treatment modality might be considered superior to the other.

Comparative Histological and Histomorphometric Results of Six Biomaterials Used in Two-Stage Maxillary Sinus Augmentation Model after 6-Month Healing

Objectives

To evaluate the performances of six different bone substitute materials used as graft in maxillary sinus augmentation by means of histological and histomorphometric analysis of bone biopsies retrieved from human subjects after a 6-month healing period.

Materials and Methods

Six consecutive patients (3 males, 3 females, aged 50-72 years), healthy, nonsmokers, and with good oral hygiene, presenting edentulous posterior maxilla with a residual bone crest measuring ≤ 4 mm in vertical height and 3 to 5 mm in horizontal thickness at radiographic examination, were selected to receive sinus augmentation and delayed implant placement. Under randomized conditions, sinus augmentation procedures were carried out using mineralized solvent-dehydrated bone allograft (MCBA), freeze-dried mineralized bone allograft (FDBA), anorganic bovine bone (ABB), equine-derived bone (EB), synthetic micro-macroporous biphasic calcium-phosphate block consisting of 70% beta-tricalcium phosphate and 30% hydroxyapatite (HA-β-TCP 30/70), or bioapatite-collagen (BC). After 6 months, bone core biopsies were retrieved and 13 implants were placed. Bone samples were processed for histological and histomorphometric analysis. CT scans were taken before and after surgery. After 4 months of healing, patients were restored with a provisional fixed acrylic resin prosthesis, as well as after further 2-4 months with a definitive cemented zirconia or porcelain-fused-to-metal crowns.

Results

There were no postoperative complications or implant failures. The histological examination showed that all biomaterials were in close contact with newly formed bone, surrounding the graft granules with a bridge-like network. No signs of acute inflammation were observed. The histomorphometry revealed 20.1% newly formed bone for MCBA, 32.1% for FDBA, 16.1% for ABB, 22.8% for EB, 20.3% for HA-β-TCP 30/70, and 21.4% for BC.

Conclusions

Within the limitations of the present investigation, all the six tested biomaterials showed good biocompatibility and osteoconductive properties when used in sinus augmentation procedures, although the FDBA seemed to have a better histomorphometric result in terms of newly formed bone and residual graft material. This trial is registered with ClinicalTrials.gov Identifier (Registration Number): NCT03496688.

Histologic and Histomorphometric Comparison between Sintered Nanohydroxyapatite and Anorganic Bovine Xenograft in Maxillary Sinus Grafting: A Split-Mouth Randomized Controlled Clinical Trial

The presence of vital bone after maxillary sinus augmentation is crucial to enhance the quality of bone-implant interface, ensuring predictable long-term results. The aims of this RCT with split-mouth design were the histologic and histomorphometric comparison of two different biomaterials in sinus elevation after 6 months of healing and the evaluation of the clinical outcomes of implants inserted in the augmented areas after 12 months of prosthetic loading. Twenty-eight patients (10 females, 18 males) were treated with bilateral sinus floor elevation with lateral approach. Pure sintered nanohydroxyapatite (NHA) and anorganic bovine bone (ABB) were used as test and active control, respectively. After six months, 52 bone biopsies were harvested from 26 patients, and 107 implants were inserted in the augmented areas. Histomorphometry showed that, in the two groups, vital bone percentages were 34.9 ± 15% (NHA) and 38.5 ± 17% (ABB) (p = 0.428), marrow spaces percentages were 44.5 ± 18% (NHA) and 43.5 ± 23% (ABB) (p = 0.866), and residual graft percentages were 20.6 ± 13% (NHA) and 22.3 ± 12% (ABB) (p = 0.638). After 6 months of healing, no statistically significant difference was present in histomorphometric outcomes between NHA and ABB groups. Implant survival rate in NHA group after 12 months of loading was 96.4%, showing no statistically significant differences with ABB group.

Maxillary Sinus Floor Elevation Using Platelet-Rich Plasma Combined With Either Biphasic Calcium Phosphate or Deproteinized Bovine Bone

PURPOSE

Maxillary sinus floor elevation procedure has the objective of augmenting available bone in atrophic posterior maxilla to allow dental implants placement. The main aim of this prospective study was to evaluate clinically and histomorphometrically the performance of biphasic calcium phosphate (BCP) used in conjunction with platelet-rich plasma (PRP) compared with demineralized bovine bone matrix (DBBM) and PRP in sinus floor elevation surgery.

MATERIALS AND METHODS

Patients candidate to sinus floor elevation were treated using either BCP and PRP or DBBM and PRP. Biopsies were retrieved using trephine bur during implant placement surgery 6 months after grafting. Clinical success of implants was evaluated 1 year after prosthesis delivery. Histomorphometric analysis was performed assessing the relative volume of newly formed bone.

RESULTS

A total of 20 patients were recruited, and 20 sinus augmentation procedures were performed, 10 for each group. A total of 42 implants were placed. One year after prosthetic loading a 100% implant survival rate was reported in both groups. Histomorphometric analysis revealed that the mean amount of new bone formation was 18.6 ± 3.3% in BCP group and it was 21.9 ± 4.9% in DBBM group, without statistically significant difference. In BCP group a greater amount of collagen type I was found with respect to DBBM group.

CONCLUSIONS

Both grafting materials led to an excellent performance regarding implant survival rate after 1 year follow-up, without any significant adverse sequelae. A similar capability of inducing new bone formation was observed in both groups, even though the higher quantity of collagen type I in BCP group may suggest a greater potential for bone formation over time as compared with DBBM.

Influence of Healing Period Upon Bone Turn Over on Maxillary Sinus Floor Augmentation Grafted Solely with Deproteinized Bovine Bone Mineral: A Prospective Human Histological and Clinical Trial

PURPOSE

To investigate the influence of maturation timing upon histological, histomorphometric and clinical outcomes when deproteinized bovine bone mineral (DBBM) was used as a sole biomaterial for staged maxillary sinus floor augmentation (MSFA).

MATERIALS AND METHODS

Patients with a posterior edentulous maxillary situation and a vertical bone height ≤ 4 mm were included in this study. A staged MSFA was carried out. After MSFA with DBBM as a sole grafting material, biopsy cores were harvested with simultaneous implant placement followed by a healing period of 5, 8, and 11 months, respectively. Micro-CT, histologic and histomorphometric analyses were performed.

RESULTS

Forty-one patients were enrolled and 38 bone core biopsies were harvested. Significantly greater BV/TV was observed between 5- and 8-month healing from micro-CT analysis. Histomorphometric analyses showed the ratio of mineralized newly formed bone increased slightly from 5 to 11 months; however, no statistically significant difference was reached (p = .409). Residual bone substitute decreased from 37.3 ± 5.04% to 20.6 ± 7.45%, achieving a statistical significant difference from of 5 up to 11 months (p < .01). Moreover, no implant failure, biological or technical complication occurred after 12-month follow-up of functional loading.

CONCLUSION

DBBM utilized as sole grafting material in staged MSFA demonstrated to be clinically effective regardless of the healing period. Histomorphometrical and micro-CT assessments revealed that at later stages of healing (8 and 11 months) there is a higher proportion of newly-bone formation compared to earlier stages (5 months). Moreover, the longer the maturation period, the substantially lesser remaining biomaterial could be expected. Even though, these facts did not seem to negatively impact on the implant prognosis 1-year after loading.

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

BACKGROUND

Deproteinized porcine bone mineral (DPBM) was recently developed and commercially available in maxillary sinus grafting, in which demineralized bovine bone mineral (DBBM) was widely used.

OBJECTIVES

The present randomized controlled clinical trial aimed to compare histological bone quality and radiographic volume stability in maxillary sinuses grafted with DPBM and DBBM.

MATERIALS AND METHODS

Twenty sinuses in 16 participants were enrolled and randomly allocated to control and test groups using sequentially numbered, sealed envelopes; laterally approached sinus grafting with DBBM and DPBM, respectively. All participants were blinded to the group assignment during the entire experiment. After standardized osteotomy at the lateral wall of the maxillary sinus, the sinus membrane was elevated, and the control or test biomaterial was grafted. Computed tomography (CT) images were taken immediately after surgery, and another CT and trephine biopsy was taken for radiographic and histological analyses after 6 months. The histological bone quality was measured as a primary outcome, and changes in the height and volume of the graft were evaluated in the reconstructed CT images as secondary outcomes.

RESULTS

Fifteen sites (7 and 8 sites for control and test group) in 11 participants were finally included in the per protocol (PP) analysis, and 16 sites (7 and 9 sites, respectively) in 12 participants were included in the intention-to-treat (ITT) analysis; there were four drop-outs and one minor protocol violation. In both statistical analyses, the test groups showed comparable new bone formation and residual biomaterials in histology, and both groups exhibited minimal volume/height changes in radiographies. However, smaller sizes of residual biomaterials were observed in the histological samples from the test compared to control sites, despite the use of the same sizes of both biomaterials.

CONCLUSIONS

The results suggested that DPBM might produce comparable bone formation and volumetric stability with DBBM in maxillary sinus grafting, however, further clinical study with longer-term periods and larger sample sizes should be needed for confirming this suggestion.

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.

Chronic Kidney Disease Impairs Bone Defect Healing in Rats

Chronic kidney disease (CKD) has been regarded as a risk for bone health. The aim of this study was to evaluate the effect of CKD on bone defect repair in rats. Uremia was induced by subtotal renal ablation, and serum levels of BUN and PTH were significantly elevated four weeks after the second renal surgery. Calvarial defects of 5-mm diameter were created and implanted with or without deproteinized bovine bone mineral (DBBM). Micro-CT and histological analyses consistently revealed a decreased newly regenerated bone volume for CKD rats after 4 and 8 weeks. In addition, 1.4-mm-diameter cortical bone defects were established in the distal end of femora and filled with gelatin sponge. CKD rats exhibited significantly lower values of regenerated bone and bone mineral density (BMD) within the cortical gap after 2 and 4 weeks. Moreover, histomorphometric analysis showed an increase in both osteoblast number (N.Ob/B.Pm) and osteoclast number (N.Oc/B.Pm) in CKD groups due to hyperparathyroidism. Notably, collagen maturation was delayed in CKD rats as verified by Masson’s Trichrome staining. These data indicate that declined renal function negatively affects bone regeneration in both calvarial and femoral defects.

Effect of two different healing times on the mineralization of newly formed bone using a bovine bone substitute in sinus floor augmentation: a randomized, controlled, clinical and histological investigation

PURPOSE

To investigate the amount of the mineralization of a bovine bone substitute material in sinus floor augmentation after healing times of 3 and 6 months.

MATERIALS AND METHODS

Fifty-one patients were randomized into two healing time groups and received sinus floor augmentations with a bovine bone material. After 3 or 6 months of healing, trephine bone biopsies were retrieved. The biopsies were processed for histological and histomorphometric evaluations to primarily investigate the amount of mineralized bone in the augmented area and secondarily compare the amount of mineralized bone in the augmented area and in the pristine bone. Statistical tests were performed to analyse the fraction of the mineralized bone (p < 0.05).

RESULTS

The biopsies of both groups showed remnants of the well-integrated bone substitute material. The histology revealed osteoblasts, osteocytes with osteoid, and osteoclasts. The mean percentage of mineralized bone in the augmented area was 23.8% (3 months group) and 23.6% (6 months group; p = 0.9246); the amount of remaining bone substitute material was 35% (3 months group) and 33.9% (6 months group; p = 0.6325).

CONCLUSION

It can be concluded that the bone maturation in the augmented sinus using the bovine bone material is similar after 3 and 6 months. Thus, implant installation after 3 months following a lateral window sinus floor augmentation approach using a bovine bone material seems to be clinically acceptable.

Peri-implant crevicular fluid levels of cathepsin-K, RANKL, and OPG around standard, short, and mini dental implants after prosthodontic loading

Purpose

Despite the high success rates of endosseous dental implants, their placement is restricted according to the height and volume of bone available. The use of short or mini dental implants could be one way to overcome this limitation. Thus, this study aimed to compare standard, short, and mini dental implants with regard to associated clinical parameters and peri-implant crevicular fluid (PICF) levels of cathepsin -K (CTSK), RANK ligand (RANKL), and osteoprotegerin (OPG), after prosthodontic loading.

Methods

A total of 78 non-submerged implants (Euroteknika, Aesthetica⁺², Sallanches, France) were installed in 30 subjects (13 male, 17 female; range, 26-62 years) who visited the clinic of the Periodontology Department, Faculty of Dentistry, Selcuk University. Sampling and measurements were performed on the loading date (baseline) and 2, 14, and 90 days after loading. Assessment of the peri-implant status for the implant sites was performed using the pocket probing depth (PPD), modified plaque index, modified gingival index, modified sulcular bleeding index, and radiographic signs of bone loss. PICF samples collected from each implant were evaluated for CTSK, RANKL, and OPG levels using the ELISA method. Keratinized tissue and marginal bone loss (MBL) were also noted.

Results

Clinical parameters statistically significantly increased in each group but did not show statistical differences between groups without PPD. Although implant groups showed a higher MBL in the upper jaw, only the standard dental group demonstrated a statistically significant difference. At 90 days, the OPG: sRANKL ratio and total amounts of CTSK for each group did not differ from baseline.

Conclusions

Within the limitations of this study, both short and mini dental implants were achieving the same outcomes as the standard dental implants in the early period after loading.

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.

Maxillary Sinus Augmentation Combining Bio-Oss with the Bone Marrow Aspirate Concentrate: A Histomorphometric Study in Humans

Purpose. To investigate the regenerative results obtained with the association of bone marrow aspirate concentrate using the Bone Marrow Aspirate Concentrate (BMAC) method to a xenogeneic bone graft (Bio-Oss) in sinus floor elevation. Materials and Methods. Using a randomized controlled study design in eight consecutive patients (age of 55.4 ± 9.2 years), 16 sinus floor lift procedures were performed with Bio-Oss alone (control group, CG, n = 8) or combined with bone marrow aspirate concentrate obtained via the BMAC method (test group, TG, n = 8). Six months after the grafting procedures, bone biopsies were harvested during implant placement and were analyzed by histomorphometry. Results. Histomorphometric analysis revealed a significantly higher amount (p < 0.05) of vital mineralized tissue in TG when compared to the CG (55.15 ± 20.91% and 27.30 ± 5.55%, resp.). For nonvital mineralized tissue, TG presented a statistically higher level of Bio-Oss resorption (p < 0.05) when compared with the CG (6.32 ± 12.03% and 22.79 ± 9.60%, resp.). Both groups (TG and CG) showed no significantly different levels (p > 0.05) of nonmineralized tissue (38.53 ± 13.08% and 49.90 ± 7.64%, resp.). Conclusion. The use of bone marrow concentrate obtained by BMAC method increased bone formation in sinus lift procedures.

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

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

Osteotome sinus floor elevation with and without grafting: an animal study in Labrador dogs

AIM

To evaluate implant stability and histological outcomes after osteotome sinus floor elevation (OSFE) procedure, and to compare new bone formation and implant osseointegration with and without grafting.

MATERIAL AND METHODS

OSFE with simultaneous implant placement was conducted bilaterally on 6 Labrador dogs. Twenty-four implants were placed. The right side sinus (Group 1) was grafted with biphasic calcium phosphate (BCP), whereas the left side (Group 2) was left without any grafting materials. The animals were euthanized 8 and 24 weeks after surgery for histological and histomorphometric assessment. Bone-to-implant contact (BIC%), alveolar bone height (ABH), bone density (BD) and grafting material density (GMD) were measured. The implant stability (ISQ) was assessed using resonance frequency analysis (RFA) at implant placement and 1, 2, 4, 8, 12, 24 weeks after surgery.

RESULTS

Endo-sinus new bone with direct contact to implant surface were observed in two groups at both time points. ABH showed no difference between groups at both time points. BIC% and BD in Group 2 (40.05%, 35.90%) was higher than those in Group 1 (23.30%,25.59%) at 24 weeks. Significant shrinkage of grafting material was seen in Group 1. The GMD in Group 1 at 8 weeks was 24.35%, while it dropped to 19.90% at 24 weeks. The changing pattern of ISQ for both groups were similar.

CONCLUSIONS

Spontaneous new bone formation and better bone-to-implant contact were found for OSFE without grafting. The grafting material application during OSFE procedure showed no advantages in histological results.