Istvan A. Urban

Horizontal ridge augmentation with a collagen membrane and a combination of particulated autogenous bone and anorganic bovine bone-derived mineral: a prospective case series in 25 patients.

This prospective case series evaluated the use of a resorbable natural collagen membrane with a mixture of autogenous bone and anorganic bovine bone-derived mineral (ABBM) for lateral ridge augmentation and subsequent implant placement. A mixture (1:1) of particulated autogenous bone and ABBM was used for lateral ridge augmentation and covered with a resorbable, natural collagen bilayer membrane to treat knife-edge ridges and prepare them for implant placement. Ridge measurements were obtained pre- and postsurgery, complications recorded, and biopsy specimens examined histologically. Seventy-six implants were placed in 25 patients with 31 knife-edge ridge surgical sites. One defect had a bone graft complication (3.2%; exact 95% confidence interval: 0.1%, 16.7%). Clinical measurements revealed an average of 5.68 mm (standard deviation [SD] = 1.42 mm) of lateral ridge augmentation after a mean 8.9-month (SD = 2.1 months) graft healing period. Clinically, all treated ridges were sufficient in width for subsequent implant placement. All implants survived with an average follow-up of 20.88 months (SD = 9.49 months). Histologic analysis of nine surgical sites showed that ABBM was connected with a dense network of newly formed bone with varying degrees of maturation. Histomorphometric analysis demonstrated that autogenous bone represented a mean of 31.0% of the specimens, ABBM 25.8%, and marrow space 43.2%. The treatment of horizontally deficient alveolar ridges with the guided bone regeneration technique using autogenous bone mixed with ABBM and a natural collagen resorbable barrier membrane can be regarded as successful. Implant success and survival need to be confirmed with long-term follow-up examinations.

Vertical ridge augmentation with titanium-reinforced, dense-PTFE membranes and a combination of particulated autogenous bone and anorganic bovine bone-derived mineral: a prospective case series in 19 patients.

PURPOSE This prospective case series evaluated the use of a new titanium-reinforced nonresorbable membrane (high-density polytetrafluoroethylene), in combination with a mixture of anorganic bovine bone-derived mineral (ABBM) and autogenous particulated bone, for vertical augmentation of deficient alveolar ridges. MATERIALS AND METHODS A mixture of ABBM and autogenous particulated bone was used for vertical ridge augmentation and covered with a new titanium-reinforced nonresorbable membrane. Ridge measurements were obtained before and after the procedure, complications were recorded, and biopsy specimens were taken for histologic examination. RESULTS Twenty vertical ridge augmentation procedures were carried out in 19 patients. All treated defect sites exhibited excellent bone formation, with an average bone gain of 5.45 mm (standard deviation 1.93 mm). The healing period was uneventful, and no complications were observed. Eight specimens were examined histologically; on average, autogenous or regenerated bone represented 36.6% of the specimens, ABBM 16.6%, and marrow space 46.8%. No inflammatory responses or foreign-body reactions were noted in the specimens. CONCLUSION The treatment of vertically deficient alveolar ridges with guided bone regeneration using a mixture of autogenous bone and ABBM and a new titanium-reinforced nonresorbable membrane can be considered successful.

Simultaneous vertical guided bone regeneration and guided tissue regeneration in the posterior maxilla using recombinant human platelet-derived growth factor: a case report.

This clinical case report describes and demonstrates successful use of recombinant human platelet-derived growth factor (rhPDGF-BB) in conjunction with autogenous bone, anorganic bone mineral, and barrier membranes to reconstruct severe alveolar bone defects. A combined sinus augmentation and vertical alveolar ridge augmentation was successfully performed. In addition, a significant amount of periodontal bone gain was achieved in close apposition to a previously denuded root surface, which is significant from a periodontal standpoint, given the possibility of vertical periodontal regeneration.

Relative Bone Width of the Edentulous Maxillary Ridge. Clinical Implications of Digital Assessment in Presurgical Implant Planning

BACKGROUND Healthy, well-structured mucosa may clinically disguise atrophic jawbone in preimplant diagnosis. PURPOSE To analyze bone width in relation to the complete ridge thickness comparing the anterior with the posterior edentulous maxilla. MATERIALS AND METHODS Data of 52 patients (mean age 62 ± 9 years) who were edentulous for at least 1 year and who received implant treatment were analyzed. Computed tomography (CT) scans were obtained and virtually analyzed in perpendicular sections of 12 maxillary positions (central and lateral incisors, canines, premolars, and first molars) using an implant planning software. Absolute thickness of complete jaw, bone, and mucosa were digitally measured at crestal and basal ridge levels allowing for relative bone width (B-rel) calculation. RESULTS Mean B-rel at crestal levels was lower than at basal levels (38.6% vs 51.5%, p < .001). Bone width increased significantly (p < .001) in the posterior maxilla at both levels, whereas the thickness of palatal and buccal mucosa was considerably stable. Mean basal B-rel ranged from 49% (6.2 ± 2.0 mm) at incisors to 59% (9.0 ± 2.3 mm) at first molars (p < .001). Mean proportion of regions showing B-rel < 50% were 43% at basal and 80% at crestal levels. CONCLUSIONS The osseous volume of a large edentulous ridge might be clinically overestimated in preimplant diagnosis, as the relative bone width was generally lower than 50%. Clinicians can use the present results of the virtual bone and mucosa measurements to have a better first estimation of the osseous proportion depending on the maxillary area. However, up to date implant therapy for the edentulous maxilla requires CT-based prosthetically driven implant planning and preferably combination with guided implant placement by transferring planning information to a surgical template.

Horizontal Ridge Augmentation using GBR with a Native Collagen Membrane and 1:1 Ratio of Particulated Xenograft and Autologous Bone: A 1-Year Prospective Clinical Study.

AIM To clinically and radiographically evaluate bone regeneration of severe horizontal bone defects. MATERIALS AND METHODS This study was designed as a single cohort, prospective clinical trial. Partially or fully edentulous patients, having less then 4 mm of residual horizontal bone width were selected and consecutively treated with resorbable collagen membranes and a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, 7 months before implant placement. Tapered body implants were inserted and loaded 3 to 6 months later with a screw retained crown or bridge. Outcomes were: implant survival rate, any biological and prosthetic complications, horizontal alveolar bone dimensional changes measured on cone beam computed tomography (CBCT) taken at baseline and at implant insertion, peri-implant marginal bone level changes measured on periapical radiographs, plaque index (PI), and bleeding on probing index (BoP). RESULTS Eighteen consecutive patients (11 females, 7 males) with a mean age of 56.8 years (range 24-78) and 22 treated sites received 55 regular platform implants. No patient dropped-out and no implants failed during the entire follow-up, resulting in a cumulative implant survival rate of 100%. No prosthetic or biological complications were recorded. Supraimposition of pre- and 7-month post-operative CBCT scans revealed an average horizontal bone gain of 5.03 ± 2.15 mm (95% CI: 4.13-5.92 mm). One year after final prosthesis delivery, mean marginal bone loss was 1.03 ± 0.21 mm (95% CI 0.83-1.17 mm). PI was 11.1% and BoP was 5.6%. CONCLUSION Within the limitation of the present study, high implant survival rate and high average bone augmentation seem to validate the use of collagen resorbable membranes with a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, for the reconstruction of severe horizontal ridge defects.

A novel cyclic RGD-containing peptide polymer improves serum-free adhesion of adipose tissue-derived mesenchymal stem cells to bone implant surfaces

Seeding of bone implants with mesenchymal stem cells (MSCs) may promote osseointegration and bone regeneration. However, implant material surfaces, such as titanium or bovine bone mineral, fail to support rapid and efficient attachment of MSCs, especially under serum-free conditions that may be desirable when human applications or tightly controlled experiments are envisioned. Here we demonstrate that a branched poly[Lys(Seri-DL-Alam)] polymer functionalized with cyclic arginyl-glycyl-aspartate, when immobilized by simple adsorption to tissue culture plastic, surgical titanium alloy (Ti6Al4V), or Bio-Oss® bovine bone substitute, significantly accelerates serum-free adhesion and enhances seeding efficiency of human adipose tissue-derived MSCs. Moreover, when exposed to serum-containing osteogenic medium, MSCs survived and differentiated on the peptide-coated scaffolds. In summary, the presented novel polypeptide conjugate can be conveniently used for coating various surfaces, and may find applications whenever quick and efficient seeding of MSCs is required to various scaffolds in the absence of serum.

Horizontal guided bone regeneration in the posterior maxilla using recombinant human platelet-derived growth factor: a case report.

This clinical case report describes and demonstrates the successful use of purified recombinant human platelet-derived growth factor in conjunction with autogenous bone, an organic bovine bone-derived mineral, and a barrier membrane to reconstruct severe alveolar bone defects. Significant horizontal bone regeneration was achieved in the posterior maxillary region. Three implants were placed into the newly formed ridge and demonstrated stable crestal bone after 36 months of loading.

Vertical Bone Grafting and Periosteal Vertical Mattress Suture for the Fixation of Resorbable Membranes and Stabilization of Particulate Grafts in Horizontal Guided Bone Regeneration to Achieve More Predictable Results: A Technical Report.

Osteosynthesis screws and titanium or resorbable pins have been recommended for fixing guided bone regeneration (GBR) membranes and stabilizing the graft. However, the removal of fixation screws or pins often requires an additional surgical procedure. This article presents a periosteal suturing technique with resorbable sutures for the fixation of grafts and membranes in GBR in single implant sites. This technique avoids potential complications of using fixation screws or pins, such as perforation of the roots when inserting the pins, and eliminates the need for a second retrieval surgery.

Vertical Ridge Augmentation and Soft Tissue Reconstruction of the Anterior Atrophic Maxillae: A Case Series.

Severe vertical ridge deficiency in the anterior maxilla represents one of the most challenging clinical scenarios in the bone regeneration arena. As such, a combination of vertical bone augmentation using various biomaterials and soft tissue manipulation is needed to obtain successful outcomes. The present case series describes a novel approach to overcome vertical deficiencies in the anterior atrophied maxillae by using a mixture of autologous and anorganic bovine bone. Soft tissue manipulation including, but not limited to, free soft tissue graft was used to overcome the drawbacks of vertical bone augmentation (eg, loss of vestibular depth and keratinized mucosa). By combining soft and hard tissue grafts, optimum esthetic and long-term implant prosthesis stability can be achieved and sustained.

Morphologic patterns of the atrophic posterior maxilla and clinical implications for bone regenerative therapy

Regenerative therapies are commonly needed prior to implant placement in the posterior maxilla following tooth extraction. The aim of this study was to investigate the anatomical features of the atrophic posterior maxilla that might affect surgical approach selection and technique and risk of intra- and postoperative complications. Cone beam computed tomography files were screened to identify pristine atrophic maxillary ridges in need of bone augmentation (ridge height < 10 mm). Ridge height and width and lateral wall thickness (LWT) were measured at different levels, and palatonasal recess and lateral wall morphology were calculated. The influence of site was assessed using generalized estimation equations. The linear correlation between parameters was estimated with Pearson coefficient, and principal component analysis (PCA) was performed to establish patterns of multiple correlations. In the 433 edentulous sites and 6,062 measurements analyzed, the strongest correlations corresponded to LWT measurements at the different levels. Most of the parameters examined presented linearity (P < .001), allowing establishment of four main morphologic patterns according to anatomical features. The anatomical structures of the atrophic posterior maxilla follow linear patterns that might predict complications due to an anatomical feature and thus success in regenerative therapy.