Sinus Grafting Procedure Research Articles

Extended platelet-rich fibrin.

Platelet-rich fibrin (PRF) has been characterized as a regenerative biomaterial that is fully resorbed within a typical 2-3 week period. Very recently, however, a novel heating process was shown to extend the working properties of PRP/PRF from a standard 2-3 week period toward a duration of 4-6 months. Numerous clinicians have now utilized this extended-PRF (e-PRF) membrane as a substitute for collagen barrier membranes in various clinical applications, such as guided tissue/bone regeneration. This review article summarizes the scientific work to date on this novel technology, including its current and future applications in periodontology, implant dentistry, orthopedics and facial aesthetics. A systematic review was conducted investigating key terms including "Bio-Heat," "albumin gel," "albumin-PRF," "Alb-PRF," "extended-PRF," "e-PRF," "activated plasma albumin gel," and "APAG" by searching databases such as MEDLINE, EMBASE and PubMed. Findings from preclinical studies demonstrate that following a simple 10-min heating process, the transformation of the liquid plasma albumin layer into a gel-like injectable albumin gel extends the resorption properties to at least 4 months according to ISO standard 10 993 (subcutaneous animal model). Several clinical studies have now demonstrated the use of e-PRF membranes as a replacement for collagen membranes in GTR/GBR procedures, closing lateral windows in sinus grafting procedures, for extraction site management, and as a stable biological membrane during recession coverage procedures. Furthermore, Alb-PRF may also be injected as a regenerative biological filler that lasts extended periods with advantages in joint injections, osteoarthritis and in the field of facial aesthetics. This article highlights the marked improvement in the stability and degradation properties of the novel Alb-PRF/e-PRF technology with its widespread future potential use as a potential replacement for collagen membranes with indications including extraction site management, GBR procedures, lateral sinus window closure, recession coverage among others, and further highlights its use as a biological regenerative filler for joint injections and facial aesthetics. It is hoped that this review will pioneer future opportunities and research development in the field, leading to further progression toward more natural and less costly biomaterials for use in medicine and dentistry.

3D assessment after maxillary sinus grafting with a porcine, a bovine and a synthetical bone substitute material. A randomized controlled clinical trial.

This randomized controlled clinical study focused on graft volume alterations after sinus floor augmentation with a deproteinized bovine bone mineral (DBBM, Geistlich Bio-Oss®), deproteinized porcine bone mineral (DPBM, THE GRAFT®) or a biphasic calcium phosphate (BCP, OSOPIA®). 28 patients with edentulous situations in the posterior maxilla with less or equal to 5 mm of residual bone height received a two- staged external sinus grafting procedure with DBBM, DPBM or BCP. CBCT scans were performed prior surgery (CBCT1), directly after surgery (CBCT2) and after a healing period of 4-6 months prior implant placement (CBCT3). CBCT scans were used to analyze volumetric alterations of the sinus grafts by virtual 3D model matching of CBCT1- CBCT2 (situation after sinus grafting) and CBCT1 and CBCT2 (situation prior implant placement). The volume of the bone graft in the maxillary sinus (volume (VOL%) directly after grafting rated as 100%) was stable after the healing period in the DBBM (VOL%: 103±4%) and the PBBM groups (VOL%: 112± 23) with no statistically significant differences concerning 3D measurements. In the BCP group, the grafted volume declined to 66± 25% (VOL%), statistically inferior to the DBBM and DPBM groups. Concerning bone graft stability/ 25 volume DBBM and DPBM show comparable outcomes. Due to resorption, BCP showed inferior bone graft volume after healing (statistically significant) compared to DBBM and DPBM.

Optimized bone grafting.

Bone grafting is routinely performed in periodontology and oral surgery to fill bone voids. While autogenous bone is considered the gold standard because of its regenerative properties, allografts and xenografts have more commonly been utilized owing to their availability as well as their differential regenerative/biomechanical properties. In particular, xenografts are sintered at high temperatures, which allows for their slower degradation and resorption rates and/or nonresorbable features. As a result, clinicians have combined xenografts with other classes of bone grafts (most notably allografts and autografts in various ratios) for procedures requiring better long-term stability, such as contour grafting, sinus elevation procedures, and vertical bone augmentations. This review addresses the regenerative properties of each class of bone grafts and then highlights the importance of understanding each of their biomechanical and regenerative properties for clinical applications, including extraction site management, contour augmentation, sinus grafting, and horizontal and vertical augmentation procedures. Thereafter, an introduction toward the novel production of nonresorbable bone allografts (NRBAs) via high-temperature sintering is presented. These NRBAs not only pose the advantage of being more biocompatible than xenografts owing to their origin (human vs. animal bone) but also display nonresorbable properties similar to those of xenografts. Thus, while packaging allografts with xenografts in premixtures specific to various clinical indications has never been permitted owing to cross-species contamination and FDA/CE requirements, the discovery and production of NRBAs allows premixing with standard allografts in various ratios without regulatory restrictions. Therefore, premixtures of allografts with NRBAs can be produced in various ratios for specific indications (e.g., a 1:1 ratio similar to an allograft/xenograft mixture for sinus grafting) without the need for purchasing separate classes of bone grafts. This optimized form of bone grafting could theoretically provide clinicians more precise ratios without the need to purchase separate bone grafts. This review highlights the future potential for simplified and optimized bone grafting in periodontology and implant dentistry.

Indirect Sinus Lift in Maxillary Posterior Region using BAOSFE Technique

Implant placement in edentulous posterior maxilla along the maxillary sinuses poses difficulties following tooth extraction due to ridge resorption and pneumatization of sinuses resulting in inadequate vertical bone height. The maxillary sinus lying close to the posterior maxillary edentulous ridge can be augmented by various methods such as lateral window sinus floor elevation, crestal approach, and grafting procedures. Summers introduced the less invasive approach for the sinus floor elevation known as osteotome sinus floor elevation technique in which the vertical bone height was attained by retaining and relocating existing bone using different graded osteotomes. He further modified this technique by addition of bone graft to the osteotomy site before sinus elevation known as bone added osteotome mediated sinus floor elevation (BAOSFE). This case report shows placement of implant in atrophic maxillary region using BAOSFE technique.

The Hammock Proposal: A Modification of Loma Linda Pouch Technique

Introduction: A technique, the "Loma Linda pouch," is introduced for repairing the perforated maxillary sinus membrane during sinus grafting procedures. The collagen membrane is then folded along the lateral access window to form a pouch that surrounds and isolates the graft material. In this review, we planned to devise a modification to the “Loma Linda pouch technique”. This ‘‘hammock’’ approach immobilizes the collagen membrane as far as possible, promotes greater blood supply, thereby increasing vital bone formation. Case presentation: When perforation occurs during elevation of the Schneiderian membrane, elevation of the membrane from the internal sinus walls must be completed. In this approach, plasma rich in growth factors is used as a graft carrier to achieve a more compact and homogeneous bone graft and to avoid particle dispersion. The rest of the procedure follows the classic sinus augmentation approach. Discussion: Ranges of techniques involve repairing perforations that range in size from 2 mm to 1.5 cm. For larger perforations (≥1.5mm), the only reported possibility is the use of a resorbable collagen membrane. Displacement of the collagen membrane is one of the most frequent complications. For this reason, perfect immobilization of the membrane is the key to success. Compared with other methods, this modified approach enhances the fixation of the collagen membrane not only on the buccal side but also on the palatal side of the sinus cavity. Conclusion: This technique achieves stable immobilization of the collagen membrane and, with it, better treatment predictability in future.

Radiographic Analysis of Graft Dimensional Changes in Transcrestal Maxillary Sinus Augmentation: A Retrospective Study.

Background. The maxillary sinus lift is a popular and predictable technique associated with implant-supported rehabilitation of the severely atrophic maxilla. The aim of the present retrospective study was to investigate the effectiveness of transcrestal maxillary sinus augmentation and the graft resorption pattern using different heterologous bone substitutes. Methods. A total of 75 sinus-grafting procedures were performed and 89 implants were placed in 66 patients, 24 males and 42 females, with mean age 67.9 ± 10.64 years (range 43–84 years). Nineteen subjects were smokers. The mean follow-up period was 93.33 ± 54.71 months (range 14–240 months). Clinical and radiographical evaluations were performed. Graft height and width were measured at baseline and at the latest follow-up. Results. Mesiodistal and vertical resorption averaged 9.3 ± 20.7% (standard deviation), and 5.04 ± 9.9% of the postoperative size, respectively, considering the graft as the unit. Linear regression analysis showed that graft resorption in both the vertical and the mesiodistal dimension is independent of the follow-up time. Conversely, there was a trend for greater resorption when increasing the postoperative graft size, in both vertical (p = 0.001) and horizontal (p = 0.007) dimensions. When grouping the dimensional changes by graft particle size (only small (<300 μm) particles, combination of small and medium (>500 μm)/large (>1000 μm) particles, and only medium/large particles), there was a trend for greater resorption associated with smaller particles, but it was not significant; neither in the mesiodistal nor in the vertical dimension (p = 0.17 and p = 0.25, respectively). No implant was lost during the observation period. In conclusion, the transcrestal technique for maxillary sinus augmentation documented a high level of predictability. The low clinical morbidity and the contextual dental implant positioning is clinically useful in relation to a significant reduction of the time required for implant restoration, a consistent decrease of the number of surgical phases, and a cost-effectiveness approach for the rehabilitation. The graft resorption pattern in all cases was compatible with persistent implant protection and support.

Patient-Related Risk Factors for Maxillary Sinus Augmentation Procedures: A Systematic Literature Review.

The posterior maxilla has traditionally presented a challenge for successful placement of dental implants due to a combination of poor bone quality, ridge atrophy, and pneumatization of the sinus floor following tooth extraction. However, with the successful and predictable surgical outcomes reported in the literature, more clinicians and patients are choosing an implant-supported restoration in the edentulous posterior maxilla. Consequently, sinus elevation and augmentation have gained more popularity. Extensive research has been conducted on types of bone graft materials and implants, less-invasive techniques to perform sinus augmentation, and timing for implant placement for sinus grafting. Despite the predictability of the techniques and biomaterials employed in sinus grafting procedures, intra- and postoperative complications are common. Much of the current literature discusses the local risk factors related to sinus augmentation, with few studies focusing on the patient-related risk factors. The purpose of this review is to identify, evaluate, and discuss the possible management of patient-related risk factors to allow for more predictable maxillary sinus floor augmentation outcomes.

Piezosurgery in periodontics: A new paradigm for traditional approaches: A review

Piezosurgery is a new method that uses piezoelectric ultrasonic vibrations to perform precise and safe osteotomies. It was first discovered by Tomaso Vercelotti to overcome the limitations of traditional instruments in oral bone surgery. Its use was first introduced in the field of preprosthetic surgery alveolar crest expansion and sinus grafting procedures. It is a favorable, scrupulous, and soft tissue sparing system for bone cutting based on low frequency ultrasonic microvibrations. The absence of macrovibration makes the instrument more feasible and allows greater intraoperative control with increase in cutting safety in the more difficult anatomical cutting zone. This article focuses on the broad range of applications of this novel technique in periodontology.

The effect of residual bone height and membrane thickness on sinus membrane perforation in crestal sinus grafting: A prospective clinical study

This study sought to determine the rate of sinus membrane perforation in patients undergoing crestal sinus grafting, as well as the effect of Schneiderian membrane thickness and residual bone height (RBH) on membrane perforation, using cone beam computed tomography. The study included 25 patients undergoing 44 crestal sinus grafting procedures. The sites for crestal sinus grafting were divided into a control group (RBH≥5mm) and a test group (RBH<5mm). All sinus grafting procedures were also categorised based on membrane thickness: group A (<1mm), group B (1–2mm), and group C (≥2mm). The rate of membrane perforation was 18.2%. The median RBH measurement was 5.59mm. No statistically significant difference in membrane perforation rate was found between the test and control groups (P=0.262). The median thickness of the Schneiderian membrane was 1.35mm. There was no statistically significant difference in membrane perforation among the three membrane thickness groups (P=0.431). No significant correlation between RBH and membrane perforation was observed, although clinical observation indicated that there was a tendency for an increased membrane perforation rate in the presence of a RBH<5mm. The perforation rate was found to be at its highest when the membrane was thinner than 1mm.

Porous Titanium Granules for Sinus Floor Augmentation: A Case Series Study

Background:Sinus grafting with autogenous bone and other bone substitutes has been shown to be a safe technique with high predictability of success, but it has not been determined which of these materials provide better osteogenic potential. The aim of the present study was to clinically and radiographically evaluate the use of Natix™ grafting material in maxillary sinus elevation procedures with simultaneous implant placement in humans.Materials and Methods:Fifteen patients (6 women and 9 men) requiring augmentation of the maxillary sinus before implant placement were voluntarily enrolled in this study. After the sinus graft procedure, a bone augmentation material of porous titanium granules (Natix™, TigranTecnologies, Malmö, Sweden) was placed into the sinus cavity. The primary stability of the fixtures was measured at baseline and 6 months following the implantation. Panoramic x-rays for objective measurements of bone height at the floor of sinus were repeated at 18 months, and 36 months postoperatively.Results:The 15 patients had in total 20 implants installed. Panoramic radiographs made 6 months post-insertion showed a radio-opaque area around the implants.Also at 6 months post-placement, all 18 implants were clinically stable and abutments were connected. Bone biopsies were taken from 1 grafted site in 1 patient. Excluding the one implant failing to achieve primary stability at baseline, the cumulative implant survival rate in this pilot study was 94.7%.Conclusion:The results of the study showed that maxillary sinus augmentation with porous titanium granules provided predictable survival of implants in 36 months.

Automatic three-dimensional analysis of bone volume and quality change after maxillary sinus augmentation.

Maxillary sinus augmentation is a widely used surgical procedure to increase the bone volume before implant placement. In order to predict the stability of the implant, analysis of the change in bone volume and quality after a sinus graft procedure is necessary. The purpose of this study was to analyze the change in volume and quality of bone graft material after maxillary sinus augmentation using cone beam computed tomography (CBCT). Maxillary sinus lift procedures using bovine bone materials (Bio-Oss, Geistrich, Swiss) without immediate implantation were performed at the Pusan National University Dental Hospital in 22 patients, from 2014 to 2017. CBCT images were captured before surgery (T1), a day after surgery (T2), and after 4 to 7 months at follow-up (T3). The T2 and T3 images were registered to the T1 image using histogram matching and intensity-based registration. A total of 30 sinuses were analyzed three-dimensionally (3-D), using self-made software MATLAB 2018a (MathWorks, Natick, Massachusetts). The volume and structural indices of the bone graft material were measured and analyzed. The average volume of graft material showed a decrease, while the average gray value showed an increase during the follow-up period, but these changes were not statistically significant. The structural indices of the graft material after histogram matching showed a significant difference in homogeneity, connectivity, thickness, and roughness at the postoperative follow-up. The volume and gray value showed no statistically significant changes after the maxillary sinus lift procedures. The results of this study show that structural analysis using histogram matching can be used as a promising tool to analyze the quality of graft materials.

Treatment of sinusitis after sinus augmentation by endoscopic sinus surgery and medications – A case report

Background Previous investigations have reported maxillary sinusitis up to 20% of patients after SFA. Postoperative acute maxillary sinusitis may cause implant failures. When sinusitis occurs, it is necessary to consult to an otolaryngologist for evaluation. It can be treated with medication and enucleation of bone graft materials. The treatment of sinusitis following sinus grafting procedures or the removal of dental implants displaced in the maxillary sinus by means of nasal endoscopy has been described. Aim/Hypothesis In this report we presented an acute maxillary sinusitis complication following sinus lifting in a patient with chronic maxillary sinusitis and treated by endoscopic sinus surgery and antibiotics without enucleating graft materials. Material and Methods Sinus augmentation was performed to the 52-year-old male patient. There were no aspects of sinus membrane perforation during procedure. After surgery, maxillary sinusitis was diagnosed and medications were prescribed by an otolaryngologist. Symptoms of sinusitis was remained, therefore endoscopic sinus surgery was conducted. Results Follow-up 1 years after implantation- No aspects of sinusitis Marginal bone & alveolar bone height was maintained. Conclusion and Clinical Implications Maxillary sinusitis is an inevitable complication of maxillary sinus augmentation in patients with a history of maxillary sinus disease. Present study reported that acute maxillary sinusitis caused by infection of the dental implants should be treated with a direct approach to sinus, regular irrigation and antibiotics. This patient developed a maxillary sinusitis following a sinus grafting procedure without penetration of alloplastic material into the residual part of the elevated sinus. Convent.

Patient-, software-, and observer-related factors associated with the time required for semi-automated measurements of the maxillary sinus volume using cone beam computed tomography (CBCT)

This study aimed to evaluate patient-, software-, and observer-related factors influencing the time required for volumetric measurements of maxillary sinuses using cone beam computed tomography (CBCT) and a commercially available software. The volumes of healthy bilateral maxillary sinuses of adult patients from CBCT images taken during a 15-month study period were measured using dedicated software by two observers. The time required for volumetric assessments was evaluated statistically with respect to the potential influence of gender, age, sinus side, sinus volume, sequence of measurement, and selection threshold of the software. The resulting average sinus volume of the 174 sinuses from 87 patients was 16.9 cm3. The average time required to measure one sinus volume was 91.8 s. Sinuses from male patients required a longer time (median of 95.5 s) for the measurements than their female counterparts (median of 87.5 s). Measurement time increased with increasing age, sinus volume and selection threshold based on calculated grey values provided by the software. The volumetric measurements and measurement times exhibited a high intra-observer agreement. The volumetric measurements were highly reproducible. Each measurement was completed within 4 minutes, though there was a marked difference in the mean measurement time between the two observers. Semi-automated volumetric measurement of the maxillary sinus with commercially available software is feasible, efficient, and reproducible. Based on these favorable findings, practitioners might consider using such volumetric instead of linear measurements to plan and analyse outcomes of sinus grafting procedures in daily clinical practice.

Patient-, software-, and observer-related factors associated with the time required for semi-automated measurements of the maxillary sinus volume using cone beam computed tomography (CBCT)

This study aimed to evaluate patient-, software-, and observer-related factors influencing the time required for volumetric measurements of maxillary sinuses using cone beam computed tomography (CBCT) and a commercially available software. The volumes of healthy bilateral maxillary sinuses of adult patients from CBCT images taken during a 15-month study period were measured using dedicated software by two observers. The time required for volumetric assessments was evaluated statistically with respect to the potential influence of gender, age, sinus side, sinus volume, sequence of measurement, and selection threshold of the software. The resulting average sinus volume of the 174 sinuses from 87 patients was 16.9 cm3. The average time required to measure one sinus volume was 91.8 s. Sinuses from male patients required a longer time (median of 95.5 s) for the measurements than their female counterparts (median of 87.5 s). Measurement time increased with increasing age, sinus volume and selection threshold based on calculated grey values provided by the software. The volumetric measurements and measurement times exhibited a high intra-observer agreement. The volumetric measurements were highly reproducible. Each measurement was completed within 4 minutes, though there was a marked difference in the mean measurement time between the two observers. Semi-automated volumetric measurement of the maxillary sinus with commercially available software is feasible, efficient, and reproducible. Based on these favorable findings, practitioners might consider using such volumetric instead of linear measurements to plan and analyse outcomes of sinus grafting procedures in daily clinical practice.

Increased Expression of Musashi-1 Evidences Mesenchymal Repair in Maxillary Sinus Floor Elevation

This study aimed to analyze the expression of Musashi-1 (MSI1) in maxillary native bone and grafted bone after maxillary sinus floor elevation. To do so, fifty-seven bone biopsies from 45 participants were studied. Eighteen samples were collected from native bone while 39 were obtained 6 months after maxillary sinus grafting procedures. Musashi-1 was analyzed by immunohistochemistry and RT-PCR. MSI1 was detected in osteoblasts and osteocytes in 97.4% (38/39) of grafted areas. In native bone, MSI1 was detected in only 66.6% (12/18) of the biopsies, mainly in osteocytes. Detection of MSI1 was significantly higher in osteoprogenitor mesenchymal cells of grafted biopsies (p < 0.001) but minor in smooth muscle and endothelial cells; no expression was detected in adipocytes. The mesenchymal cells of the non-mineralized tissue of native bone showed very low nuclear expression of MSI1, in comparison to fusiform cells in grafted areas (0.28(0.13) vs. 2.10(0.14), respectively; p < 0.001). Additionally, the detection of MSI1 mRNA was significantly higher in biopsies from grafted areas than those from native bone (1.00(0.51) vs. 60.34(35.2), respectively; p = 0.029). Thus, our results regardig the significantly higher detection of Musashi-1 in grafted sites than in native bone reflects its importance in the remodeling/repair events that occur after maxillary sinus floor elevation in humans.

Lateral sinus grafting for implant therapy

Sinus grafting procedure is used to increase the osseous tissue for implant-supported prosthetic purposes. The sinus floor elevation (SFE) technique is the most commonly used technique for the implant rehabilitation of an atrophic posterior maxilla. SFE is a predictable procedure performed achieving high implant survival rate and its success depends on an accurate radiographic and clinical analysis.

Cone-beam computed tomography versus orthopantomography in sinus lift procedures: Two-dimensional versus three-dimensional imaging

Context: The present study was undertaken to do a comparative evaluation of the role of cone-beam computed tomography (CBCT) imaging and orthopantomography (OPG) for preoperative implant planning in combination with sinus grafting procedures to assess sinus anatomy and morphology and the existing bone height in three-dimensions (3D). Aim: The aim of the present study was to assess sinus anatomy and morphology and the existing bone height in all the 3D. Materials and Methods: Pre- and postoperative assessment of maxillary sinuses was done in 17 patients who underwent implant therapy in combination with sinus augmentation procedures using CBCT and OPG. These patients were subjected to orthopantomographs and CBCT imaging both preoperatively and postoperatively. CBCT imaging helped decide the type of sinus augmentation procedure best suited for the patients as per the individual needs and depending on the residual alveolar bone height, timing of implant placement, sinus morphology, anticipation of complication, and comparative analysis between pre- and postprocedural gain in vertical alveolar bone height and increase in bone density. Statistical Analysis Used: The results were tabulated and statistically analyzed using paired and unpaired t-tests. Results: In the majority of cases, there was a concordance between the treatment types based on pre- and postoperative CBCT scans. The assessment of sinus morphology revealed a significantly higher detection rate of aberrations in the form of sinus mucosal hypertrophy and septae on CBCT which were imperceptible on routine radiographs. The most appealing result was that vertical alveolar bone height could be measured precisely, and there was a significant increase in surgical confidence and a significantly better prediction of complications when using CBCT imaging. Conclusions: A preoperative planning based on CBCT imaging seems to improve sinus diagnostics and helps execute a better treatment plan. Furthermore, it is a good tool for the comparison of vertical alveolar bone height pre- and postoperatively following sinus augmentation procedures using various graft materials.

Sinus-Lift Ways and Types of Sinus Augmentation and Use of Piezo-Surgery Device for Fenestration of Sinus Maxillaries

Maxillary sinus floor augmentation (also termed sinus lift, sinus graft, sinus augmentation or sinus procedure) is a surgical procedure which aims to increase the amount of bone in the posterior maxilla (upper jaw bone), in the area of the premolar and molar teeth, by lifting the lower Schneiderian membrane (sinus membrane) and placing a bone graft [2]. When a tooth is lost the alveolar process begins to remodel. The vacant tooth socket collapses as it heals leaving an edentulous (toothless) area, termed a ridge [3]. This collapse causes a loss in both height and width of the surrounding bone. In addition, when a maxillary molar or premolar is lost, the floor of the maxillary sinus expands, which further diminishes the thickness of the underlying bone. Overall, this leads to a loss in volume of bone that is available for implantation of dental implants, which rely on osseointegration (bone integration), to replace missing teeth [1]. The goal of the sinus lift is to graft extra bone into the maxillary sinus, so more bone is available to support a dental implant. A Special form of Reconstruction of bone, especially changing the vertical structure of the maxillary Sinus floor in the upper jaw and the establishment of the mucous membranes of Sinusitis purpose of dental implant called Sinuslift [4, 5, 6 &amp; 8]. Distance-maxillary sinus is often so low that an implant can not be included in stable long enough. With the incorporation of bone material or bone grafting, maxillary sinus floor, ‘grow’ and that this level can be implanted implants safe. Sinuslift distinguish Extern and Intern [9,10].

Histological and radiological evaluation of sintered and non-sintered deproteinized bovine bone substitute materials in sinus augmentation procedures. A prospective, randomized-controlled, clinical multicenter study.

The objective of this study is to histologically and radiologically compare a sintered and a non-sintered bovine bone substitute material in sinus augmentation procedures. Thirty-three patients were included in the clinically controlled randomized multicentre study resulting in a total of 44 treated sinuses. After lateral approach, sinuses were filled with either a sintered (SBM, Alpha Bio's Graft®) or a non-sintered (NSBM, Bio Oss®) deproteinized bovine bone substitute material. The augmentation sites were radiologically assessed before and immediately after the augmentation procedure as well as prior to implant placement. Bone trephine biopsies for histological analysis were harvested 6months after augmentation whilst preparing the osteotomies for implant placement. Healing was uneventful in all patients. After 6months, radiological evaluation of 43 sinuses revealed a residual augmentation height of 94.65% (±2.74) for SBM and 95.76% (±2.15) for NSBM. One patient left the study for personal reasons. Histological analysis revealed a percentage of new bone of 29.71% (±13.67) for SBM and 30.57% (±16.07) for NSBM. Residual bone substitute material averaged at 40.68% (±16.32) for SBM compared to 43.43% (±19.07) for NSBM. All differences between the groups were not statistically significant (p > 0.05, Student's t test). Both xenogeneic bone substitute materials showed comparable results regarding new bone formation and radiological height changes in external sinus grafting procedures. Both bone substitute materials allow for a predictable new bone formation following sinus augmentation procedures.

Bacterial influence on consolidation of bone grafts in maxillary sinus elevation.

The aim of this study was to identify microorganisms present on the maxillary sinus floor at the moment of sinus elevation surgery and, using tomography, to investigate the repercussions these might have for regenerated bone 9months after the procedure. 174 patients (90 women and 84 men) with a mean age of 55.92years underwent 227 sinus elevations (120 left sinus, 107 right sinus). As the membrane was lifted, a sample of the maxillary sinus floor was collected with a cotton swab, and placed on a blood agar and chocolate agar culture to incubate for 48h at 37°C; the samples then underwent microbiological analysis. Orthopantomographs and computerized tomographs were made immediately after the sinus grafting and after 9months to measure the amount of remaining and regenerated bone in vertical and transversal direction. 18.1% of 227 cultures were bacteria-positive. 45% of the germs were of the Streptococcus genus, most of which belonged to the S.viridans group (61.1%). Patients presenting negative cultures had 5% more regenerated bone than patients with bacteria-positive cultures, which represents an additional 2.28 mmof vertical bone (with a confidence interval between 0.83mm and 3.73mm). Patients with bacteria-positive cultures obtained previously to the sinus grafting procedure have greater risk of bone height loss after 9months, which indicates that bacterial contamination may influence bone graft regeneration.