Nabih Nader

Physicochemical characteristics of bone substitutes used in oral surgery in comparison to autogenous bone.

Bone substitutes used in oral surgery include allografts, xenografts, and synthetic materials that are frequently used to compensate bone loss or to reinforce repaired bone, but little is currently known about their physicochemical characteristics. The aim of this study was to evaluate a number of physical and chemical properties in a variety of granulated mineral-based biomaterials used in dentistry and to compare them with those of autogenous bone. Autogenous bone and eight commercial biomaterials of human, bovine, and synthetic origins were studied by high-resolution X-ray diffraction, atomic absorption spectrometry, and laser diffraction to determine their chemical composition, calcium release concentration, crystallinity, and granulation size. The highest calcium release concentration was 24. 94 mg/g for Puros and the lowest one was 2.83 mg/g for Ingenios β-TCP compared to 20.15 mg/g for natural bone. The range of particles sizes, in terms of median size D50, varied between 1.32 μm for BioOss and 902.41 μm for OsteoSponge, compared to 282.1 μm for natural bone. All samples displayed a similar hexagonal shape as bone, except Ingenios β-TCP, Macrobone, and OsteoSponge, which showed rhomboid and triclinic shapes, respectively. Commercial bone substitutes significantly differ in terms of calcium concentration, particle size, and crystallinity, which may affect their in vivo performance.

Horizontal and Vertical Reconstruction of the Severely Resorbed Maxillary Jaw Using Subantral Augmentation and a Novel Tenting Technique with Bone from the Lateral Buccal Wall

AimThe aim of this study was to evaluate the effect of using the lateral wall bone in sinus lifting two-dimensional reconstruction on bone augmentation.Patients and MethodsTen patients affected by class V or VI maxillary atrophy with less than 3 mm of residual horizontal ridge were selected. Using a piezo-ultrasonic surgery tip bony lateral wall was cut. To expose native bone to the bone graft, multiple perforations, made through the cortical plate of the recipient site with a round bur. Once the bony buccal wall was adjusted it was fixed away from the ridge with two 1.5 x 13 mm bone fixation screws. Deficiencies created between the bony buccal wall and the ridge was filled with a mineralized cortical bone. A pericardium membrane was then placed on the graft. A biopsy for histologic evaluation was made.ResultsThe data analysis in bone volume changes reported significant differences between the anterior and posterior locations before and after grafting (p < 0.05). The biopsy shows mature cancellous bone with predominantly lamellar structure.ConclusionThe use of the lateral wall bone in sinus lift surgery showed significant increase in bone volume.

Subantral Augmentation With Mineralized Cortical Bone Allograft Material: Clinical, Histological, and Histomorphometric Analyses and Graft Volume Assessments.

Purpose:The aim of this study was to clinically and histologically evaluate the effect of using mineralized cortical bone allograft in sinus lift augmentation and to 3-dimensionally quantify volumetric changes in maxillary sinuses augmented over a 2-year period. Materials and Methods:Eleven patients affected with less than 3 mm of residual ridge were enrolled in the study. After sinus grafting with a mineralized bone allograft, the site was covered with a collagen wound dressing. During implant placement 4 months later, a biopsy was obtained for histological and histomorphometry evaluations. Bone volume changes were also evaluated. Results:Biopsies showed mature cancellous bone with a predominantly lamellar structure. The well-vascularized intertrabecular spaces were filled with connective tissue and bone marrow. Histomorphometry evaluations revealed a mean 43.76 ± 1.47% of bone marrow, 40.16 ± 1.35% of mineralized bone and 16.59 ± 0.55% of woven bone. The mean of residual particles was 0.47 ± 0.01%. Volumetric measurements showed a mean volume of grafted material 16.24 ± 1.55 cm3 at T0, 14.48 ± 1.48 cm3 at T1, and 13.06 ± 1.39 cm3 at T2. The mean volume retraction was 10.83% of the initial total volume at (T0-T1) and 9.8% at (T1-T2). Conclusions:The clinical and histological results indicated that mineralized cortical bone allograft promoted de novo bone formation and can be used for sinus lift procedure.

Sinus Floor Augmentation With Ambient Blood and an Absorbable Collagen Sponge: A Prospective Pilot Clinical Study

Purpose: The aim of this study was to clinically, radiologically, and histologically evaluate a sinus augmentation technique using a resorbable collagen sponge to maintain space between the Schneiderian membrane and the residual crestal bone. Materials and Methods: Patients with partially edentulous maxillae were clinically and radiographically evaluated for implant placement. A total of 10 consecutive patients with the bone height for implant placement (<4.0 mm) were enrolled in the study. The lateral maxillary wall was surgically exposed and the Schneiderian membrane was carefully elevated. A collagen wound dressing was placed in the antral area between the sinus floor and the raised membrane. The vertical sinus floor height was calculated using cone-beam computed tomography before the surgical procedure (baseline) and at 6 months postoperative. Immediately after the second scan, a core biopsy was removed for histological evaluation. The biopsy site was then further prepared for implant placement in the same location. Results: Biopsies showed mature cancellous bone with a predominantly lamellar structure. Well-vascularized intertrabecular spaces were filled with connective tissue and bone marrow. Analysis of bone height changes showed significant mean (SD) differences before and after procedures in anterior (2.67 ± 0.62 mm and 11.15 ± 1.1 mm), medial (2.98 ± 0.55 mm and 10.96 ± 0.77 mm), and posterior (3.17 ± 0.91 mm and 10.63 ± 0.51 mm) maxillary jaw locations (P = 0.005). Conclusion: The collagen sponge provided an effective substrate for osseous regeneration of the sinus floor.

Current State, Treatment Modalities, and Future Perspectives of Sinus Floor Elevation (SFE)

Nowadays, more than half (54.2 %) of the implant rehabilitations in the edentulous posterior maxilla are involved with an SFE procedure prior to implant placement (Seong et al. 2013).

Introduction and Scientific Background of Sinus Floor Elevation (SFE)

In a constantly aging society, the need for maxillary implant rehabilitation is increasing. In fact, the regeneration of the physiological function of the dento-maxillary system is crucial for improvement in life quality.

Crestal Sinus Floor Elevation (SFE) Approach: Overview and Recent Developments

Dental implant placement in the posterior maxilla remains a challenge due to maxillary sinus pneumatization. SFE procedures via lateral approach have overcome this obstacle, although it is considered to be a rather aggressive approach. In an attempt to reduce such morbidity, several techniques using osteotomes and different specialized instruments have been introduced to reach the sinus floor via crestal approach: Summers (Compendium 15:152, 1994a; Compendium 15:698, 1994b) described a one-stage crestal SFE approach originally indicated in the presence of a moderate residual bone height (RBH) and combined to simultaneous implant placement (OSFE, BAOSFE…), which was considered to be simpler and less invasive when compared to the lateral SFE. However, the main limitation of this “blind” crestal approach is the uncertainty of membrane integrity as a result of lack of visibility. Therefore, despite their high success rate, criticism on the safety of the crestal technique may be expressed.

Physicochemical characterization: Comparative evaluation of three allograft biomaterials and autogenous bone

Objectives: Bone substitutes (BSs) used in oral surgery include allografts, xenografts, and synthetic materials that are frequently used to compensate bone loss or to reinforce repaired bone by encouraging new bone in growth into the defect site. The aim of this study was to evaluate a number of physical and chemical properties in a variety of allografts biomaterials used in oral surgery and to compare them with those of autogenous bone. Materials and Methods: Autogenous bone and three different allograft biomaterials were studied by high-resolution X-ray diffractometry (XRD), atomic absorption spectrometry, laser diffraction, and checked for their chemical composition, calcium release concentration, crystallinity, and granulation size. Results: The highest calcium release concentration was 24.94 mg/g for Puros ® and the lowest one was 4.05 mg/g for OsteoSponge ® compared to 20.15 mg/g to natural bone. The range of particles size, in term of median size D 50 , varied between 630.47 μm for Puros ® and 902.41μm for OsteoSponge, ® compared to 282.1μm for natural bone. Bone and Puros ® displayed a hexagonal shape as bone except and OsteoSponge ® which showed a triclinic shape. Conclusion: A BS of choice depends largely on its clinical application that is associated to its biological and mechanical performance. These morphological differences between biomaterials greatly influence their in vivo behavior of biomaterials. Significant differences were detected in terms of calcium concentration, particles size, and crystallinity.