Bone Scraper Research Articles

Histological assessment of a novel de-epithelialization method for connective tissue grafts harvested from the palate. An experimental study in cadavers

ObjectivesThis study aims to compare the histological outcomes of three distinct de-epithelialization methods used in (connective tissue grafts) CTG harvested from the palate.Materials and methodsAn experimental study using nine cadaver head specimens was carried out to compare 3 different de-epithelialization techniques for CTG. Eighteen samples were randomly allocated to three study groups: bone scraper, diamond bur and extraoral removal with a scalpel. The main outcome variable was the graft surface percentage without epithelium remains. Additionally, the time employed, and the graft thickness were also measured.ResultsSixteen CTGs were analyzed. The extraoral scalpel group presented a total surface area with no epithelium of 58.84% (22.68) and a mean de-epithelialization time of 3.7 min; the intraoral diamond bur group had 88.24% (41.3) of the surface with no epithelium and took 1.455 min, and the intraoral bone scraper showed 97.98% (5.99) of surface without epithelium and a mean time of 0.815 min (P < 0.05). Histological analysis showed significant differences between the bone scraper and the extraoral group (P = 0.009).ConclusionThe de-epithelialization technique with a bone scraper seems to be the most effective and fastest de-epithelialization technique for CTG. These findings need to be confirmed in future clinical studies with larger samples.Clinical relevanceThe use of bone scrapers, could be a simple, effective and fast technique to de-epithelialize connective tissue grafts harvested from the palatal area for both novice and experienced surgeons.

Anterior Aesthetic Zone Reconstruction with Allogenic Bone Shell and Autogenous Bone Chips - An Evaluative Study.

Horizontal alveolar bone loss hinders dental implant placement. Reconstruction of alveolar deficiency is mandatory to establish an ideal foundation for implant-supported prosthetic restoration. The aim of this study is to evaluate the regenerated bone following anterior aesthetic zone reconstruction with allogenic bone shell and autogenous chips. A total of 15 deficient sites in the aesthetic zone were treated using allograft bone shells, which were fixed away from the alveolar ridge using microscrews, and the created gap was filled with autogenous chips harvested intraorally using a bone scraper. Clinically, one patient experienced wound dehiscence in the second post-operative week, and the graft had to be removed one month postoperatively due to infection. Three patients experienced shell detachment six months later but that did not hinder the placement of an implant. Radiographically, there was horizontal bone gain that was statistically significant six months postoperatively. The mean apical bone gain was 2.64 mm (±0.99 standard deviation [SD]). The mean mid-level bone gain was 3.44 mm (±0.52 SD). The mean crestal bone gain was 2.36 mm (±0.85 SD). Histologically, vital trabecular bone tissue with osteocytes and osteoblasts was detected. Moreover, the presence of reversal lines indicated bone formation and remodelling after grafting. This technique generates sufficient bone tissue in previously horizontally deficient alveolar ridges for subsequent implant placement and omits the need for a second surgical site with its consequent morbidity. The low complication rate reported needs further modifications to extrapolate results.

Vertical Bone Augmentation with GBR Pocket Technique: Surgical Procedure and Preliminary Results

Nowadays, guided bone regeneration (GBR) is a predictable technique in both vertical and horizontal bone defects treatment. GBR Pocket Technique is an original surgical approach adopted in order to reduce the invasiveness of traditional procedures. The aim of this work is to describe the surgical procedure of GBR Pocket Technique in vertical bone augmentation and to compare the clinical outcomes of this technique with the results reported in literature of vertical bone augmentation and crestal bone remodeling achieved after 1 year after implants insertion. Twenty-eight patients were recruited for this study and received 28 GBR procedures in the posterior region due to vertical and horizontal defects. A 50/50 mixture of autologous bone component and heterologous bone of equine origin was then made with the use of a bone scraper tunnel with internal reservoir. A PTFE-d membrane with titanium reinforcement was then fixed to the residual bone structure with screws in order to maintain the graft in place. Radiographic checks were made before graft procedures and implants insertion, then 6 months later and 1 year after implants placement. The average bone augmentation after surgery seems to be aligned, or even better, than the average reported in literature with alternative surgical approach; in addition, the mean crestal remodeling after 1 year and the rate of complications are aligned with other previous surgical techniques with a vertical bone augmentation of 8.78 mm ± SD 2.39 and a bone remodeling after 1 year of 0.59 mm ± SD 0.29. The advantages of this technique are preservation of blood circulation and consequently risk of flap necrosis, dehiscence, and graft exposure. This technique also reduces mucosal healing times even if it takes longer surgical time. GBR Pocket Technique is the use of a minimal-invasive surgical wound to reduce patient morbidity and compliance.

Lateral Window Osteotomy in Maxillary Sinus Augmentation: Does a Combination of Two Surgical Protocols Offer Any Advantage? A Retrospective Analysis of Clinical Outcome.

Maxillary sinus augmentation using the lateral bone window approach has been well documented and studied, with the advent of many newer techniques and instruments. It is prudent that operators make a choice based on scientific evidence and feasibility guided by each case. The purpose of this study is to analyze whether a combination of more than one method could prove beneficial when compared to any one method alone. Radiographic and clinical data from 48 augmented maxillary sinuses in 42 male and female patients was collected and the clinical outcome analyzed based on different clinical parameters. Data collected from 48 augmented maxillary sinuses was divided into 4 groups based on the osteotomy method used. A comparison was made between rotary diamond bur (Group 1), the piezosurgical device (Group 2), a hand-held bone scraper (Group 3) and a combination of method 1 and 3 (Group 4). Mean wall thickness for the maxillary Bucco-facial wall was measured for all cases. Clinical parameters measured included time taken to complete the osteotomy, membrane perforation, operator fatigue, anastomotic vessel damage and autogenous bone collected. Mean time taken for Group 1 was 17.33min, Group 2 was 34.83min, Group 3 was 38min, Group 4 19.5min. Membrane perforations were highest in Group 1 & 2 at 16.66%. Groups 2 and 4 showed the least chances of damage to the vessel at 16.66%. Significance of operator fatigue was highest at 16.66% in Group 4. It was concluded that there may be an advantage in selecting a combination of surgical protocols in accordance with the lateral wall thickness. The advantages may extrapolate to safety, simplicity and ergonomics of surgical approach compared to any one technique alone.

Optimizing autologous bone contribution to implant osseointegration.

Autologous bone can be harvested from the flutes of a conventional drill or from a bone scraper; here we compared whether autologous bone chips generated by a new slow-speed instrument were more osteogenic than the bone chips generated by conventional drills or bone scrapers. Additionally, we tested whether the osteogenic potential of bone chips could be further improved by exposure to a Wnt signaling (WNT) therapeutic. Osteotomies were prepared in fresh rat maxillary first molar extraction sockets using a conventional drill or a new osseo-shaping instrument; titanium alloy implants were placed immediately thereafter. Using molecular/cellular and histologic analyses, the fates of the resulting bone chips were analyzed. To test whether increasing WNT signaling improved osteogenesis in an immediate post-extraction implant environment, a WNT therapeutic was introduced at the time of implant placement. Bone collected from a conventional drill exhibited extensive apoptosis; in contrast, bone generated by the new instrument remained in situ, which preserved their viability. Also preserved was the viability of the osteoprogenitor cells attached to the bone chips. Exogenous treatment with a WNT therapeutic increased the rate of osteogenesis around immediate post-extraction implants. Compared with conventional drills or bone scrapers, a new cutting instrument enabled concomitant site preparation with autologous bone chip collection. Histology/histomorphometric analyses revealed that the bone chips generated by this new tool were more osteogenic and could be further enhanced by exposure to a WNT therapeutic. Even though gaps still existed in placebo controls and liposomal WNT3A (L-WNT3A) cases, the area of peri-implant bone was significantly greater in L-WNT3A treated sites.

The management of vertical bone defects in the posterior area – The challenge

Background The rehabilitation in the posterior area in the absence of adequate quantity and quality of bone represents one of the most complicated challenges in the implantology. The management of the atrophy can be performed with different methods and materials. The autogenous bone is still considered the best material for the regeneration of the bone defects particularly when we have to recovery atrophy in the 3 D dimension. Aim/Hypothesis The present study evaluated the reliability and predictability of the treatment of severe bone loss in the posterior maxilla and mandible. The inclusion criteria were the advanced bone defects due to previously lost teeth and complications of cases already treated with other materials and technique Material and Methods Of 32 consecutive patients were treated in the posterior area (premolar and molar) after failures of previous treatment or in the cases of severe 3D bone atrophy and followed from 4 years to 8 years post-operative. In all the cases was performed only a 2 stage approach due to the severe bone loss. All the augmentation were carried out according to Khoury's biological concept. The harvested bone block from the mandibular retromolar area with the Microsaw, was splitted in 2 thin blocks and they were screwed to reconstruct at least two bone walls with the micro screws allowing a 3D reconstruction of the alveolar crest. The space between the two blocks were filled with particulate bone chips collected with a bone scraper. 22 reconstructions were carried out in the maxilla and 18 in the posterior mandible. No membranes were used. Implants were placed 4 months after the augmentation. The soft tissue management and augmentations were performed during the implant exposure 3 months post-operative Results A primary good healing occurred in all the 32 patients. No exposure of the grafts was registered after the augmentation or at the moment of implant insertion. The grafted bone after 4 months showed a good revascularization and stable bone volume showing the same consistence and bleeding like the native bone. Therefore, we proceeded to insert 93 implants with regular diameter (3.4–4.5 mm) and length (9.5–13 mm) in the augmented posterior area in the mandible and in the maxillary as we planned. In only two patients a secondary bone augmentation with local harvested bone was necessary due to incomplete bone regeneration (both cases were complication of previous reconstruction techniques). All the patients presented after a follow-up between 4 and 8 years a good function and aesthetical result with the correct hight of the crowns. The radiographic control, repeated every year, documented the stability of the grafted and regenerated bone. Conclusion and Clinical Implications The management of bone defects in 3D dimension represents a big challenge particularly when the demand of the patient is really important. With the biological concept we were able to ensure a long-term stability with very good outcomes for aesthetics and function. The use of autogenous bone offered more safety and reduced considerably the time of the treatment in comparison to other augmentation materials remaining nowadays more reliable and predictable.

Ridge Augmentation Comparing an Allograft Plus Autogenous Bone Chips to an Osteoinductive Demineralized Bone Matrix

The primary aim of this randomized, controlled, blinded, clinical trial was to compare a mix of particulate allograft and harvested autogenous particles (Autogenous) to an osteoinductive demineralized bone matrix (DBM) allograft on clinical and histologic outcomes for horizontal ridge augmentation procedure. Fourteen patients with a horizontal ridge defect with at least 1 adjacent tooth were entered into this study. The test group of 7 subjects received corticocancellous particulate allograft (Mineross) mixed with autogenous bone chips (70:30) harvested using a bone scraper (SafeScraper TWIST). Seven subjects in the control group received DBM (Optecure-CCC). Both groups had a corticocancellous particulate allograft overlay and an acellular dermis membrane (ADMG) (AlloDerm GBR) to cover the grafts. For the Autogenous group, there was a gain of 3.5 ± 1.4 mm while the DBM group gained 3.8 ± 1.6 mm (P < 0.05). Vertical change was minimal for both groups (P > 0.05). The Autogenous group had a mean of 35% vital bone while the DBM had 39% (P > 0.05). Both treatments provided similar gain of ridge width and minimal loss of ridge height. The autogenous bone chips did not provide any additional benefit when compared with allograft alone that had lot verified osteoinductive activity.

The efficacy of bone scraper for bone window osteotomy in the course of sinus augmentation

The efficacy of bone scraper for bone window osteotomy in the course of sinus augmentation

Regenerative capacity of augmented bone in rat calvarial guided bone augmentation model

PurposeGuided bone regeneration (GBR) is the most widely used technique to regenerate and augment bones. Even though augmented bones (ABs) have been examined histologically in many studies, few studies have been conducted to examine the biological potential of these bones and the healing dynamics following their use. Moreover, whether the bone obtained from the GBR procedure possesses the same functions as the existing autogenous bone is uncertain. In particular, little attention has been paid to the regenerative ability of GBR bone. Therefore, the present study histologically evaluated the regenerative capacity of AB in the occlusive space of a rat guided bone augmentation (GBA) model.MethodsThe calvaria of 30 rats were exposed, and plastic caps were placed on the right of the calvaria in 10 of the 30 rats. After a 12-week healing phase, critical-sized calvarial bone defects (diameter: 5.0 mm) were trephined into the dorsal parietal bone on the left of the calvaria. Bone particles were harvested from the AB or the cortical bone (CB) using a bone scraper and transplanted into the critical defects.ResultsThe newly generated bone at the defects' edge was evaluated using micro-computed tomography (micro-CT) and histological sections. In the micro-CT analysis, the radiopacity in both the augmented and the CB groups remained high throughout the observational period. In the histological analysis, the closure rate of the CB was significantly higher than in the AB group. The numbers of cells positive for runt-related transcription factor 2 (Runx2) and tartrate-resistant acid phosphatase (TRAP) in the AB group were larger than in the CB group.ConclusionsThe regenerative capacity of AB in the occlusive space of the rat GBA model was confirmed. Within the limitations of this study, the regenerative ability of the AB particulate transplant was inferior to that of the CB particulate transplant.

Collagen barrier membranes adsorb growth factors liberated from autogenous bone chips.

Collagen membranes serve as barriers to separate bone grafts from soft tissues. Bone grafts harvested with a bone scraper release growth factors activating transforming growth factor-β (TGF-β) signaling in mesenchymal cells. The aim of the present pilot study was to determine whether collagen membranes adsorb molecules from bone-conditioned medium (BCM) with the capacity to provoke the expression of TGF-β target genes invitro. Collagen membranes were soaked in aqueous extracts from fresh and demineralized bone chips placed in cell culture medium. Recombinant human TGF-β1 served as control. Gingival fibroblasts were seeded onto the washed collagen membranes and evaluated for the expression of adrenomedullin, pentraxin 3, interleukin 11, and proteoglycan 4. Cell viability and morphology with phalloidin staining were also determined. Incubation of collagen membranes with BCM for at least one minute caused fibroblasts to decrease the expression of adrenomedullin and pentraxin 3, and to increase the expression of interleukin 11 and proteoglycan 4. Four different membrane treatments - incubated with recombinant TGF-β1, pre-wetted with saline solution, exposed to UV light, and dry out and stored one week at room temperature - also provoked significant changes in gene expression. Likewise, conditioned medium from demineralized bone chips caused gene expression changes. BCM did not alter the viability or morphology of gingival fibroblasts. These findings demonstrate that collagen membranes rapidly adsorb the TGF-β activity released from bone chips, a molecular process that might contribute to guided bone regeneration.

Impact of bone graft harvesting techniques on bone formation and graft resorption: a histomorphometric study in the mandibles of minipigs

Harvesting techniques can affect cellular parameters of autogenous bone grafts in vitro. Whether these differences translate to in vivo bone formation, however, remains unknown. The purpose of this study was to assess the impact of different harvesting techniques on bone formation and graft resorption in vivo. Four harvesting techniques were used: (i) corticocancellous blocks particulated by a bone mill; (ii) bone scraper; (iii) piezosurgery; and (iv) bone slurry collected from a filter device upon drilling. The grafts were placed into bone defects in the mandibles of 12 minipigs. The animals were sacrificed after 1, 2, 4 and 8 weeks of healing. Histology and histomorphometrical analyses were performed to assess bone formation and graft resorption. An explorative statistical analysis was performed. The amount of new bone increased, while the amount of residual bone decreased over time with all harvesting techniques. At all given time points, no significant advantage of any harvesting technique on bone formation was observed. The harvesting technique, however, affected bone formation and the amount of residual graft within the overall healing period. Friedman test revealed an impact of the harvesting technique on residual bone graft after 2 and 4 weeks. At the later time point, post hoc testing showed more newly formed bone in association with bone graft processed by bone mill than harvested by bone scraper and piezosurgery. Transplantation of autogenous bone particles harvested with four techniques in the present model resulted in moderate differences in terms of bone formation and graft resorption.

The impact of four harvesting techniques on the cell viability and osteogenic behaviour of cells in autogenous bone grafts: A critical appraisal of an experimental study

The investigators tested the null hypothesis that there would be no differences between the different bone harvesting techniques with regard to cell viability, cell activity and osteogenic potential of grafted cells. Bone grafts were harvested from the mandibles of 12 miniature pigs using four different harvesting techniques: bone milling, bone scraping, bone drilling (bone slurry) and piezosurgery. Cell viability was determined according to an immunoassay of released signalling molecules and gene expression that affect bone formation and resorption. The osteogenic activity of conditioned graft-sampled media was assessed in a bioassay using isolated bone cells. Cells in autogenous bone grafts obtained by using a bone mill and a bone scraper showed a higher viability and a stronger osteogenic potential than those from piezosurgery and bone drilling (slurry). This study contributed towards the understanding of the impact of harvesting techniques on the viability and osteogenic behaviour of grafted cells.

Risk of bacterial contamination of bone harvesting devices used for autogenous bone graft in implant surgery

BackgroundVarious instruments have been developed for collecting bone debris during intraoral autogenous bone graft procedures in implant surgery. The aim of this study was to quantitatively determine the degree of contamination in bone debris collected by different devices.MethodsTwelve patients underwent autogenous bone collection using a bone chisel, bone scraper, trephine drill, and bone filter during bone augmentation surgery as a part of implant therapy, and the total bacterial count in bone debris collected by each was determined.ResultsFollowing anaerobic incubation, bacterial colony formation was found in all of the samples. The mean colony forming units (CFU)/g in samples collected by the trephine drill was found to be significantly lower than that of samples obtained with the other devices, while those values for samples collected by the bone scraper and bone filter was significantly higher as compared to the bone chisel and trephine drill.ConclusionThe bacterial levels may still carry the infection risk. Thus prophylactic antibiotic therapy maybe indicated when using bone particles for intraoral augmentation procedures.

Impact of Bone Harvesting Techniques on Cell Viability and the Release of Growth Factors of Autografts

Autogenous bone grafts obtained by different harvesting techniques behave differently during the process of graft consolidation; the underlying reasons are however not fully understood. One theory is that harvesting techniques have an impact on the number and activity of the transplanted cells which contribute to the process of graft consolidation. To test this assumption, porcine bone grafts were harvested with four different surgical procedures: bone mill, piezosurgery, bone drilling (bone slurry), and bone scraper. After determining cell viability, the release of molecules affecting bone formation and resorption was assessed by reverse transcription polymerase chain reaction and immunoassay. The mitogenic and osteogenic activity of the conditioned media was evaluated in a bioassay with isolated bone cells. Cell viability and the release of molecules affecting bone formation were higher in samples harvested by bone mill and bone scraper when compared with samples prepared by bone drilling and piezosurgery. The harvesting procedure also affected gene expression, for example, bone mill and bone scraper samples revealed significantly higher expression of growth factors such as bone morphogenetic protein-2 and vascular endothelial growth factor compared with the two other modalities. Receptor activator of nuclear factor kappa B ligand expression was lowest in bone scraper samples. These data can provide a scientific basis to better understand the impact of harvesting techniques on the number and activity of transplanted cells, which might contribute to the therapeutic outcome of the augmentation procedure.

Viability of maxillary bone harvesting by using different osteotomy techniques. A pilot study.

The use of autogenous grafts is still considered in bone regeneration surgeries. However, the bone cell viability of such grafts after being harvested from donor sites remains a matter of debate. The aim of the present study is to evaluate particulated and block bone cell viability, in terms of presence or absence of apoptosis and necrosis, obtained from different maxillary intra-oral harvesting methods: bone scraper, rotary carbide burs and piezoelectric device. Five healthy patients were enrolled in the study. The patients required sinus augmentation by lateral window approach. The bone was harvested by the bone scraper, piezoelectric device and rotary surgical instrument. The samples were processed with the Annexin V/FITC (fluorescein isothiocyanate stain) kit and were analyzed by means of Fluoresence-Activated Cell Sorted (FACS) technique. Within the limitations of this pilot study, the results indicated that autogenous bone chips collected from the three harvesting methods presented a large percentage of apoptotic cells, although large scale production of necrotic cells was not detected. In summary, although rotary surgical instrument and piezoelectric devices are frequently used instruments for oral osteotomy, fresh autogenous bone chips collected from them did not present a viable bone cell source.

Evaluation of Graft Cell Viability—Efficacy of Piezoelectric Versus Manual Bone Scraper Technique

The aim of the present study was to compare the influence of 2 different bone scrapers with respect to graft quality. The study was conducted as a prospective, controlled experimental study of patients selected from the outpatient unit of the Department of Oral Surgery and Radiology (Dental Clinic, Medical University, Graz, Austria). Bone samples were obtained during routine lower third molar removal. Both a manual bone scraper (MS) and a piezoelectric device (PD) were used in directly adjacent regions in each case. As variables, the chip morphology, cell viability, and osteogenic differentiation were investigated. For statistical analysis, the Student t test and Fisher's exact test (P < .05) were applied. A total of 20 patients (12 women and 8 men, mean age 28.15 ± 5.8 years) were included in the study. A series of 40 bone samples was obtained during lower third molar removal. MS and PD enabled similar intraoral harvest of bone chips. In vitro outgrowth of adherent cells was found in 90% of the MS and 80% of the PD samples after 7 to 18 days, without statistical significance (P = .67). Similar cell viability of outgrowing cells in both groups was observed (94.7% ± 2.2% in the MS group and 94.1% ± 1.6% in the PD group). Reverse transcriptase-polymerase chain reaction analysis and the staining pattern verified osteopotent cells in both groups. Both manual and piezoelectric techniques are adequate harvesting technologies for limited intraoral augmentations. Our results did not show an advantage for the piezoelectric device.

Osteogenic Potential of Autogenous Bone Grafts Harvested with Four Different Surgical Techniques

The osteogenic potential of autogenous bone grafts is superior to that of allografts and xenografts because of their ability to release osteoinductive growth factors and provide a natural osteoconductive surface for cell attachment and growth. In this in vitro study, autogenous bone particles were harvested by four commonly used techniques and compared for their ability to promote an osteogenic response. Primary osteoblasts were isolated and seeded on autogenous bone grafts prepared from the mandibles of miniature pigs with a bone mill, piezo-surgery, bone scraper, and bone drill (bone slurry). The osteoblast cultures were compared for their ability to promote cell attachment, proliferation, and differentiation. After 4 and 8 hrs, significantly higher cell numbers were associated with bone mill and bone scraper samples compared with those acquired by bone slurry and piezo-surgery. Similar patterns were consistently observed up to 5 days. Furthermore, osteoblasts seeded on bone mill and scraper samples expressed significantly elevated mRNA levels of collagen, osteocalcin, and osterix at 3 and 14 days and produced more mineralized tissue as assessed by alizarin red staining. These results suggest that the larger bone graft particles produced by bone mill and bone scraper techniques have a higher osteogenic potential than bone slurry and piezo-surgery.

Safe Harvesting of Outer Table Parietal Bone Grafts Using an Oscillating Saw and a Bone Scraper: A Refinement of Technique for Harvesting Cortical and “Cancellous”-Like Calvarial Bone

Calvarial bone is a readily available source of bone for preimplantation augmentation procedures of the alveolar process. However, the calvaria consist mostly of cortical bone, and cancellous bone of the diploic space is scarce. A bone scraper (Safescraper Twist; META, Reggio Emilia, Italy) was used to create a beveled trough around the calvarial outer table graft to facilitate its removal with an oscillating saw. Using the scraper, copious amounts (>10 mL) of "cancellous"-like bone could be collected. This new application of the Safescraper Twist obviated milling down additional cortical pieces.

Sinus Graft With Safescraper: 5-Year Results

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. 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. 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. 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.

Scintigraphic, Histologic, and Histomorphometric Analyses of Bovine Bone Mineral and Autogenous Bone Mixture in Sinus Floor Augmentation: A Randomized Controlled Trial—Results After 4 Months of Healing

To test our null hypothesis stating that the mixture of autogenous cortical bone scrapings and bovine bone mineral (BBM) in a ratio of 1:4, compared with BBM alone, would have no significant effect on new bone formation 4 months after maxillary sinus floor augmentation. Twenty-four patients presenting with alveolar bone height of less than 5 mm in the narrowest zone between the sinus floor and alveolar crest were randomly assigned to 2 treatment groups in this randomized controlled trial. We augmented 12 maxillary sinuses with a mixture of BBM and cortical autogenous bone graft, which was collected from the lateral wall of the maxillary sinus by a bone scraper, and 12 maxillary sinuses with BBM alone. Four months postoperatively, new bone formation in the augmented sinus sites was evaluated through bone scintigraphy, as well as histologic and histomorphometric analyses of the biopsy specimens obtained during implant placement. Data were statistically analyzed by independent-samples t test. Scintigraphically detectable new bone formation did not differ significantly between the groups (P > .05). Histologic findings showed that the new bone bridged between BBM particles and BBM underwent resorption by osteoclasts with or without the addition of autogenous bone graft. According to histomorphometric findings, the difference between the percentages of newly formed bone in the sinuses augmented with graft mixture (25.73%) and BBM alone (24.19%) was statistically nonsignificant (P > .05). The addition of autogenous cortical bone scrapings to BBM in a ratio of 1:4, compared with BBM alone, does not markedly increase new bone formation 4 months after maxillary sinus lifting.