Sinus Elevation Surgery Research Articles

The Role of Bone Tacks in Sinus Floor Lift Surgery: A Single-Center Experience.

Background: Maxillar atrophy is a prevalent condition associated with diminished bone volume, which precludes the conventional placement of dental implants. Sinus floor lift is a surgical procedure that aims to address this atrophy through the insertion of a graft within the sinus cavity. A multitude of techniques have been documented in the international literature for the management of the sinus bone window, though each approach has its own set of advantages and disadvantages. Methods: The present study is a retrospective analysis of traditional sinus floor lift surgery, comparing the outcomes of two surgical approaches: placement of a collagen membrane over the maxillary lateral bone window with or without bone tacks. The study enrolled a total of 48 consecutive patients. Twenty-four patients underwent sinus floor lift surgery, with the placement of a collagen membrane over the maxillary lateral bone window without bone tacks (control group). The remaining 24 patients underwent the same procedure, but with bone tacks (study group). All patients received an amoxicillin 875 mg + clavulanic acid 125 mg administration for six days and underwent Cone Beam Computed Tomography (CBCT) before the sinus floor lift surgery and six months later before the implant surgery. The parameters measured on the preoperative Cone Beam Computed Tomography (CBCT) scan included residual bone, the preoperative thickness of the lateral bone in the center, and the distance between the lateral wall and the medial wall of the sinus. Only the bone height increment was measured on the postoperative CBCT scan. Postoperative complications and the visual analogue scale (VAS) score were also recorded. A statistical analysis was performed, and the correlation between the parameters was evaluated using Pearson's correlation coefficient. A comparison of the mean of the parameters between the treatment group and the control group was conducted using the t-test. Results and Conclusions: The study group was found to have superior outcomes in terms of bone height increment (p = 0.001) and VAS after 7 days (p = 0.11) compared to the control group. The novel application of bone tacks on the collagen membrane over the bone window following sinus elevation surgery was associated with superior outcomes in terms of bone height and reduced pain at seven days, as measured by the VAS, with no postoperative complications.

Effects of Sinus Membrane Stabilization by Dental Implant Placement and Membrane Suturing on Endo-Sinus Bone Gain in Cases of Lateral Sinus Elevation Performed Without Graft Material.

To investigate the effects of sinus membrane stabilization (via suturing) and dental implant placement on the endo-sinus bone formation in lateral sinus elevations performed without grafting. Maxillary sinus elevation surgery using the lateral approach was performed bilaterally on 30 New Zealand white rabbits. The maxillary sinus areas were divided into control and test groups. In the control group, a titanium screw was placed after sinus membrane elevation; in the test group, the sinus membrane was sutured to the lateral walls, and a titanium screw was placed in the center of the alveolar crest. The subjects were sacrificed at 4 and 8 weeks. Then samples were collected, and a microcomputed tomography (micro-CT) analysis was performed. In addition, the volume of newly formed bone, percentage of osseointegration, sinus volume, residual bone height, and implant protrusion length were measured using micro-CT analysis. The sinus volume, volume of newly formed bone, and percentage of osseointegration in the test group were significantly higher than in the control group at 4 weeks (P = .01, P = .04, P = .02, respectively). While the volume of newly formed bone was 17.1 ± 3.08 mm3 in the control group, it was 26.9 ± 14.26 mm3 in the test group at 4 weeks. The volume of newly formed bone significantly decreased from 26.9 ± 14.26 mm3 to 17 ± 3.66 mm3 at 8 weeks (P = .02). No significant difference in residual bone height was found at 4 and 8 weeks (P = .07). No significant difference in implant protrusion length was found between the control and test groups (P = .18). Protrusion length and new bone formation in the sinus showed a negative relationship (P = .01). Suturing the sinus membrane to the lateral sinus wall is an effective approach for increasing osseointegration, bone volume, and sinus volume in the short term. A slow-absorbing suture material can be used to maintain sinus and bone volumes in the long term.

Quantification of Bone Height and Bone Volume Around Dental Implants After Open Maxillary Sinus Elevation Surgery Using CBCT.

Purpose: To assess, using CBCT, the volume and height of bone formation after open maxillary sinus elevation without the use of grafts. Materials and Methods: The study was retrospective and included 24 patients with a total of 67 implants. CBCT examinations were conducted at baseline (0 to 43 days postsurgery) and after an average healing period of 6.2 months (range: 5.1 to 7.8 months). The image analysis included metal artifact reduction, registration, and a standardized protocol for segmenting the anatomical structures of the maxillary sinus, including calculating the 3D volumetric changes after bone formation. Conventional manual 2D measurement of vertical bone formation was executed for comparison. Clinical factors assumed to be relevant for bone formation were obtained from patient medical records. Results: One implant was lost before prosthetic loading, representing an early implant loss rate of 1.5%. Differences in intra- and interexaminer reproducibility were registered for the conventional 2D method (P < .05). The average vertical bone formation measured with the 2D method was 4.8 mm (4.6 to 5.0 mm), covering 60.2% of the implant height within the sinus. The average volumetric bone formation measured with the developed 3D image-analysis method was 801 mm3 in total and 195 mm3 in a restricted region around each implant. Bone formation was registered in 62% of the volume of the restricted region. A correlation regarding bone formation was found between the two methods (R2 = 0.705). Clinical factors such as age, smoking, general health, and postoperative complications did not correlate with the amount of bone formed. Conclusion: CBCT image analysis is a promising method for objective 3D evaluation of bone formation after sinus elevation. A correlation was seen between the manually measured bone height (2D) and the bone volume in a restricted region around each implant using the developed method (3D). Reducing visual interpretation minimizes errors related to examiner reliability. Clinical factors did not significantly affect the volumetric bone formation.

Clinical, Radiographic, and Histological Evaluation of the Mineralized Plasmatic Matrix/Xenograft Mixture in Maxillary Sinus Floor Augmentation (A Randomized Controlled Clinical Trial)

Introduction: Maxillary sinus pneumatization and alveolar ridge resorption following the extraction of posterior teeth make the installation of dental implants in the maxillary posterior region challenging. The direct sinus lift procedure proved to be a viable treatment option for such conditions. Aim of the study: to evaluate the mineralized plasmatic matrix/xenograft mixture in sinus elevation surgery. Materials and Methods: Eighteen patients were selected and randomly allocated into two groups; study group received a mineralized plasmatic matrix/xenograft mixture, while the control group received xenograft alone following sinus lifting. Results: The early wound healing index score showed a non-significant difference between both groups. Also, bone height was evaluated at the 6-month follow-up period, and there was a non-statistically significant difference. Core biopsies were taken for histological examination by H&amp;E from both groups, revealing the presence of a more mature bone matrix in relation to the test group. Conclusion: The addition of mineralized plasmatic matrix to xenograft can speed up bone formation, thus reducing treatment duration.

Influence of the contact area of the sub-antral space with sinus bone and the Schneiderian membrane on osteogenesis in lateral window sinus elevation surgery: a prospective experiment

BackgroundOsteogenesis of lateral window sinus elevation surgery is the key to placement of the subsequent implant, excessive collapse of the sub-antral space may adversely affect long-term stability of implants. At present, few studies focus on the influence of the contact area of the sub-antral space on osteogenesis. This study evaluated whether the change in the contact area of the sub-antral space with maxillary sinus bone and the Schneiderian membrane can affect osteogenesis.MethodsCone beam computed tomography (CBCT) images were collected of patients requiring maxillary sinus floor elevation (residual bone height < 6 mm) for standard-length implant placement before surgery, after surgery, and at 6-month follow-up visits. The postoperative sub-antral space volume (V1) and surface area (S1), and the remaining volume after six months of healing (V2) were measured. Then, the contact area of sub-antral space with maxillary sinus bone (Sbc) and the Schneiderian membrane (Smc), the absorbed volume during healing (Va), and the percentage of remaining volume (V2%) and absorbed volume (Va%) were calculated. The correlation between anatomical parameters was analyzed using multiple linear regression.ResultsA total of 62 maxillary sinuses from 56 patients were augmented, of which 57 were considered for the final analysis (5 withdrew due to perforation). Multiple linear regression results demonstrated that Sbc was significantly positively correlated with Va (β coefficient = 0.141, p < 0.01) without correlation between Smc and Va (β coefficient = − 0.046, p = 0.470). There was a positive correlation between Sbc and V2% (β coefficient = 2.269, p < 0.05).ConclusionsThis study confirmed that the size of the Sbc in lateral window sinus elevation surgery affected osteogenesis after six months of healing. Clinicians should assess the sinus contour type preoperatively, then consider whether it is necessary to expand the range of the Schneiderian membrane elevation to avoid excessive collapse of the sub-antral space.Trial registration: Chinese Clinical Trial Registry (ChiCTR), ChiCTR2200057924. Registered 22 March 2022–Retrospectively registered.

Use of platelet- and leukocyte-rich fibrin (L-PRF) as an alternative for tissue regeneration in sinus lift surgery

This study aimed to understand how fibrin rich in platelets and leukocytes acts as an alternative for tissue regeneration in surgeries for maxillary sinus elevation. This integrative review was developed in six steps, where the guiding question was formulated according to the PICo strategy. Thus, a total of 142 publications were searched and a total of 23 articles were selected for this review after applying the inclusion and exclusion criteria. Platelet- and leukocyte-rich fibrin (L-PRF) has been increasingly investigated as a potential bioactive substance for more effective bone regeneration, not only because it is considered an easily obtained autogenous material, but also due to its high concentration of fibrin, platelets and leukocytes, assisting in the process of angiogenesis, thanks to its growth factors, which contributes to bone formation when associated with grafts, as it multiplies fibroblasts and osteoblasts. Furthermore, for the surgical method, the use of L-PRF decreases the dispersion of the graft particles used, helping to condense more mineral and consequently resulting in a smaller volume introduced into the maxillary sinus, thus minimizing the time to obtain vertical bone height. However, since the preparation is properly autologous, the amount of L-PRF acquired is insufficient, causing a disadvantage in its use. In this sense, we realize the importance of L-PRF in maxillary sinus elevation surgery, as it is a simple, cheap and the most accessible technique for the production of autologous fibrin membrane or platelet concentrate.

Retrospective study on the merits of bone grafts and the influence of implant protrusion length after osteotome sinus elevation surgery.

This study aims to evaluate the endo-sinus bone remodeling of dental implants placed via osteotome sinus floor elevation (OSFE) after 6 months and using different implant protrusion lengths and bone grafts through cone beam computed tomography (CBCT). Ninety-six patients with 124 implants were included and assigned into four groups. Group 1: implant protrusion length<4 mm with bone graft; group 2: implant protrusion length>4 mm with bone graft; group 3: implant protrusion length<4 mm without bone graft; group 4: implant protrusion length>4 mm without bone graft. Apical bone gain (ABG), cortical bone gain (CBG), bone density gain (BDG), and marginal bone loss (MBL) were observed and analyzed at baseline and 6 months after implant surgery. The CBG in grafted groups 1 and 2 was higher than that in non-grafted groups. The ABG and BDG were higher in non-grafted groups 3 and 4 than in grafted groups, and the levels in group 3 were higher than those in group 4. The CBG in grafted group 2 was higher than that in group 1. No significant difference was observed in MBL analysis. The BDG of IPL<4 mm implants was higher than IPL>4 mm implant when bone grafts were not applied. No relevance was observed between IPL and CBG. Bone grafts can accelerate endo-sinus bone remodeling by increasing CBG and dissipating the influence of IPL on BDG.

Maxillary Implant Placement in a Limited Residual Bone Height

The limitation of residual bone height (RBH) and vital structures such as sinuses in the maxillary often make the implant placement procedure becomes complicated. Clinicians may perform sinus elevation prior to implant placement to accommodate the length of the implant fixture. Sinus elevation is an invasive procedure and complication may occur during the surgery including the most frequent complication is perforation of Schneiderian membrane. Objectives: To discuss a comprehensive management of implant placement and its complication step by step from surgical procedures to crown placement Case Report: 67-year-old female patient with partial edentulism in the right maxillary region, presence of sinus septum, and RBH was 4mm. The patient was planned to do sinus elevation surgery prior to implant placement, perforation of the Schneiderian membrane occurred while surgery performed and pericardium membrane was attached around the perforation site. Sinus re-entry and implant placement were performed after 3 months followed by prosthetics procedures in the next 6 month. Conclusion: Dental implant is a complicated treatment and complication may occur during the placement, thus a comprehensive management is very essential to minimize the risk of complications.

Histologic and histomorphometric analysis of two biomaterials of xenogenous origin for maxillary sinus elevation: a clinical study.

Objective: This study analyzed two xenogenous biomaterials based on deproteinized bovine bone mineral applied for maxillary sinus elevation. Method and materials: Fourteen patients were submitted to maxillary sinus augmentation with one of the following biomaterials: Criteria Lumina Bone Porous (test group) or Geistlich Bio-Oss (control group), both of large granules (1 to 2 mm). After 6 months, trephine biopsies were collected at the time of implant placement: 27 samples (11 patients) in the test group; 7 samples (3 patients) in the control group. Biopsies were analyzed by descriptive histology and histomorphometry, in which the percentages of newly formed bone, residual biomaterial particles, and connective tissue were evaluated. Results: Histomorphometry showed means for test and control groups, respectively, of 32.41% ± 9.42% and 26.59% ± 4.88% for newly formed bone, 22.89% ± 4.58% and 25.00% ± 4.81% for residual biomaterial, and 44.70% ± 9.54% and 48.41% ± 3.36% for connective tissue. There were no differences between groups (P &gt; .05). Conclusion: This study concluded that Criteria Lumina Bone Porous presented similar histologic and histomorphometric characteristics to Geistlich Bio-Oss 6 months after sinus elevation surgery, identifying the tested biomaterial as an interesting alternative for bone augmentation in the maxillary sinus.

Levantamento de seio maxilar bilateral por duas técnicas diferentes com concomitante instalação de implantes: relato de caso

Esse artigo buscou demonstrar, através de um relato de caso clínico, a abordagem de levantamento de seio maxilar bilateral por duas diferentes técnicas, uma traumática via janela lateral e uma atraumática através da crista óssea, associadas à instalação de implantes osseointegrados. Paciente com 75 anos, gênero feminino procurou atendimento na clínica do Curso de Extensão em Implantodontia em uma universidade do Rio de Janeiro com quadro álgico em região de molares superiores. Após anamnese, exame clínico e análise da tomografia computadorizada, evidenciou-se extensa lesão de furca nos elementos 16 e 26, sendo indicada exodontia e reabilitação com implantes oseeointegrados. Ainda, devido à pouca altura óssea subantral, o levantamento de seio maxilar bilateral foi incluído ao plano de tratamento. No lado direito, foi realizada a técnica de Summers e no lado esquerdo a técnica da janela lateral associada ao uso de biomaterial sintético particulado e membrana de colágeno reabsorvível. A radiografia panorâmica de controle pós-cirúrgico demostrou o êxito das duas técnicas com adequada relação anatômica do enxerto e de ambosmplantes ao leito receptor. Assim, a cirurgia de elevação do seio maxilar com a concomitante instalação de implantes se mostrou um procedimento seguro, de boa previsibilidade e baixa taxa de complicações.

Sinus membrane elevation and implant placement.

Sinus Schneiderian membrane elevation surgery is widely performed for dental implant placement in the maxillary posterior region. With regard to sinus elevation surgery, various complications can occur and lead to implant failure. For successful implants in the maxillary posterior region, the clinician must be well acquainted with sinus anatomy and pathology, a variety of bone graft materials, the principles of sinus elevation surgery, and prevention and management of complications.

Graftless Maxillary Sinus Floor Augmentation with Simultaneous Porcine Bone Layer Insertion: A 1- to 5-Year Follow-up Study.

Evidence suggests that maxillary sinus floor augmentation via a lateral approach can be performed without positioning a bone graft inside, when one or more implants can be placed simultaneously. The aim of this study was to test if the placement of a porcine cortical bone layer underneath the sinus membrane can increase bone formation and implant stability. One hundred seventy-two patients with posterior maxilla atrophy needing implant rehabilitation were selected. Two hundred six sinus augmentation procedures were performed via a lateral approach, and 295 implants were placed in the same session of the sinus elevation surgery. In all the surgeries, a porcine cortical bone layer was placed underneath the sinus membrane, without using any graft material. After 6 to 7 months of healing, the implants were uncovered, then restored with porcelain-fused-to-metal crowns and monitored with a followup of 1 to 5 years. The implant cumulative success rate was 95.2%, while the residual bone crest height changed from 2.67 ± 1.11 mm to 12.54 ± 1.42 mm, with an increase of 9.87 mm on average. Marginal bone resorption was 0.83 mm on average after 1 year of loading, while the mean implant stability measured at the moment of implant placement and 6 to 7 months later increased from an implant stability quotient (ISQ) of 62.61 ± 5.7 to an ISQ of 70.07 ± 8.2. This study confirms the validity of the graftless sinus elevation surgery when simultaneous implant placement is performed. The use of a porcine cortical bone layer seems to increase, from a radiologic point of view, the amount of bone around the implants, reducing healing time, cost, and biologic complications for the patient.

Risk Factor Analysis Affecting Sinus Membrane Perforation During Lateral Window Maxillary Sinus Elevation Surgery.

To analyze risk factors affecting sinus membrane perforation (SMP) during sinus floor elevation (SFE) procedures using the lateral window technique (LWT). For patients with SFEs using the LWT, patient-related risk factors (age/sex/smoking/diabetes) and surgical-anatomical-related risk factors (stage approach/sinus side/residual ridge height/sinus membrane thickness/previous surgical interventions) were compared between perforated and nonperforated sites and were evaluated for their influence affecting SMP. Additionally, SMPs were further subdivided into small/moderate (< 10 mm) or large (≥ 10 mm) in dimension, which were also analyzed for risk factors and consecutively for their influence on perforation. The study sample comprised 434 SFE procedures in 355 patients; 94/355 patients (26.5%) presented SMP in 103 of 434 SFE procedures (23.8%). SFE procedures with (n = 103) and without (n = 331) SMP did not differ for patient-related risk factors but differed significantly (P = .001) for surgical-anatomical factors as follows: residual ridge height (3.05 ± 1.35 mm vs 4.15 ± 1.46 mm), sinus membrane thickness (1.2 ± 0.5 mm vs 2.6 ± 1.1 mm), prevalence of staged procedures (78.6% vs 57.7%), presence of maxillary sinus septa (75.7% vs 14.2%), presence of thin (< 1.5 mm) mucosa biotype (62.1% vs 29%), and previous oral surgical interventions (37.9% vs 16.3%). In the multivariate analysis, significant associations of SMP were found with the presence of sinus septa (odds ratio [OR] = 31.992; P = .001), residual ridge height (OR = 1.563; P = .007), sinus membrane thickness (OR = 1.057; P = .001), presence of thin (< 1.5 mm) sinus biotype (OR = 8.883; P = .001), previous surgical interventions (OR = 4.689; P = .002), and smoking habits (OR = 2.238; P = .030). For inducing a large (≥ 10 mm) SMP, the presence of thin sinus membrane thickness/thin sinus membrane biotype (OR = 5.319; P = .006; OR = 22.222; P = .001) and reduced alveolar ridge height (OR = 0.629; P = .026) were assessed as being significant risk factors. In general, the presence of sinus septa, thin sinus mucosa, staged procedures, and previous surgical interventions are the main risk factors inducing SMP for SFE using the LWT. In particular, the presence of thin sinus membrane in conjunction with a staged procedure significantly increases the risk for a large SMP.

Implant Surgery with Both Sinus Bone Graft in the Maxillary edentulous patient: A Case Report

There are a variety of prosthetic methods for restoring edentulous patients. Among them, the dental implant is a stable and easily applicable option. When the remaining bone is insufficient for supporting the dental implant, alveolar bone augmentation can stably retain implant, and its prognosis will be favorable. The maxillary sinus elevation with bone graft procedure is relatively easy and has a good prognosis. In these cases, remaining maxillary teeth were extracted, bone grafts with maxillary sinus elevations were performed at the bilateral maxillary molar region at a onemonth interval, and ten implants were placed seven months later. Two weeks after the sinus elevation surgery, the sutures were removed. Postoperative healing was normal without any inflammatory reaction, and the implant-supported fixed prosthesis was delivered to the patient. The patient was satisfied with the results from the esthetic and functional aspects. Implant surgery to rehabilitate the edentulous area are a useful and attractive procedure. It is helpful to increase the implant stability by sinus grafting bone.

Risk factors in lateral window sinus elevation surgery.

Maxillary sinus augmentation is the most predictable of the pre-prosthetic surgical procedures. There are, however, known and well-documented complications that can and do occur. The most common are the intraoperative complications of sinus membrane perforation and bleeding, and the postoperative complications of sinus graft infections, sinus infections, and sinusitis. The majority of these complications can be prevented, or their incidence greatly reduced, through a thorough understanding of maxillary sinus anatomy, the multifaceted etiologies of these conditions, and the steps that can be taken to avoid them. This volume of Periodontology 2000 will discuss both the preoperative and intraoperative procedures that will prevent these untoward outcomes and the necessary treatment modalities that will limit their adverse effects.

The clinical and radiographic outcomes of Schneiderian membrane perforation without repair in sinus elevation surgery.

The aim of this comparative study was to evaluate the clinical outcome of nonrepair of the perforated maxillary sinus membrane compared to the nonperforated cases. A retrospective comparative study was performed by identifying all lateral window sinus augmentation procedures, which were done during a defined period. Demographic data, systemic diseases, and smoking habits of patients were recorded. Thickness of the Schneiderian membrane and the amount of residual bone before surgery were measured by cone-beam computed tomography (CBCT). In case of perforation, no attempt was made to repair the membrane. Alloplast was used for bone augmentation. The thickness of the Schneiderian membrane and gained bone height were recorded using CBCT at the time of prosthesis delivery. Sixty-three patients with 65 sinuses were included in this retrospective study. The rate of sinus perforation was 39%. There was a significant association between the presence of sinus pathoses before surgery and the occurrence of Schneiderian membrane perforation (P = 0.03). The Schneiderian membrane was significantly thicker in patients with perforation compared to the patients without perforation (P < 0.001). There was no correlation between the size of the perforation and the thickness of the Schneiderian membrane. Most of the perforations (83%) occurred at the mesial and middle part of the lateral window. The Schneiderian membrane thickness was decreased significantly in both groups after the sinus elevation procedure (P < 0.05). The bone graft height was stable over the follow-up period in both groups (P > 0.05). There was no implant failure in any of the groups. Nonrepair of the Schneiderian membrane perforation did not adversely affect the clinical and radiographical outcomes. There were higher intraoperative and postoperative complications in the nonrepair group.

Bone Volume Assessment Around Dental Implants After Open Maxillary Sinus Elevation Surgery: A Quantitative Approach to CBCT Images.

Cone beam computed tomography (CBCT) is an important imaging technique in maxillofacial evaluations. However, application-specific image analysis methods aimed at extracting quantitative information from these images need to be further developed. The aim of this study was to provide a robust and objective method that could assess radiologic changes around dental implants after sinus elevation surgery with simultaneous implant placement. The study was performed retrospectively on patients fulfilling the inclusion criteria. The included patients had been CBCT scanned preoperatively, at baseline (early after surgery), and 6 months postoperatively. In order to quantify the radiologic changes, an image analysis workflow was developed based on the postoperative baseline and 6-month scans. The workflow included metal artefact reduction, registration, and a standardized protocol for semiautomatic segmentation. Validation of different steps of the method was conducted by comparing scans from all time points. Comparison of constant volumes (eg, screws and bony parts not subjected to change) was used. Additionally, the Dice similarity coefficient (DSC) was used to measure the overlap of the segmentations. The study included nine maxillary sinuses from six patients. The bone formation was quantified and visualized in 3D. In the validation, no significant differences were found for the constant volumes at the different scanning time points. The DSC showed accurate results with values > 0.92. The method presented in this study provides an objective and robust evaluation of bone formation around dental implants. The same methodologies can be applied in other studies of dental CBCT images, eg, for comparison of grafting materials or surgical strategies.

Maxillary Sinus Elevation Surgery with ChronOS and Autogenous Bone Graft: Immunohistochemical Assessment of RUNX2, VEGF, TRAP, and Osteocalcin.

The purpose of this study was to evaluate a composite graft of ChronOS, a beta-tricalcium phosphate (β-TCP), mixed 1:1 with an autogenous bone graft in human maxillary sinus augmentation. A total of 12 maxillary sinuses were grafted with an autogenous bone graft (control group), and 9 maxillary sinuses were grafted with ChronOS mixed 1:1 with an autogenous bone graft (test group). After 6 months, biopsy samples were obtained concurrent to the placement of dental implants and were subjected to histomorphometric and immunohistochemical analyses for Runt-related transcription factor 2 (RUNX2), vascular endothelial growth factor (VEGF), tartrate-resistant acid phosphatase, and osteocalcin. Histologic analysis of samples obtained from the test group revealed the presence of immature bone, while samples from the control group indicated lamellar bone formation. However, both types of bone grafts were well vascularized. The new bone formation averaged 25.4% ± 6.4% in the test group and 38.6% ± 10.5% in the control group (P = .001). Immunostaining of samples in the test group showed high cellular turnover. The outcomes of this study demonstrate a delay in bone formation but intense cellular differentiation after 6 months of bone graft healing in the test group. The amount of immature bone and the immunostaining for RUNX2 and VEGF provide evidence of an osteogenic pathway that can improve the bone formation rate.

Use of autogenous bone and beta-tricalcium phosphate in maxillary sinus lifting: histomorphometric study and immunohistochemical assessment of RUNX2 and VEGF

The aim of this study was to compare the use of beta-tricalcium phosphate (β-TCP) (chronOS) with autogenous bone grafts alone in maxillary sinus elevation surgery. The test samples were β-TCP alone, β-TCP mixed with autogenous bone grafts (1:1), and autogenous bone grafts alone. Twelve maxillary sinuses were grafted with β-TCP (group 1), nine with β-TCP+autogenous bone graft (group 2), and 12 with autogenous bone graft (group 3). After 6 months, biopsies were obtained concurrent to the placement of dental implants; these were subjected to histomorphometric analysis and immunohistochemical analysis for runt-related transcription factor 2 (RUNX2) and vascular endothelial growth factor (VEGF). The average bone formation in group 1 was 46.3±11.6% in the pristine bone region, 47.6±9.9% in the intermediate region, and 44.8±22.1% in the apical region; in group 2, values were 35.0±15.8%, 32.5±13.7%, and 32.8±16.0%, respectively; in group 3, values were 43.1±16.0%, 31.0±13.0%, and 46.1±16.3%, respectively. Immunostaining of samples in group 2 showed high cellular activity and immature bone; this differed from groups 1 and 3, in which mature bone was demonstrated. Thus, this study showed that β-TCP presents the same behaviour as autogenous bone graft, which makes it a good bone substitute.

Maxillary Sinus Elevation Surgery with ChronOS and Autogenous Bone Graft: Analysis of Histometric and Volumetric Changes.

The aim of this study was to compare the bone resorption rate and histometry of ChronOS, a beta-tricalcium phosphate (β-TCP), mixed with autogenous bone grafts (1:1) with that of autogenous bone grafts alone in maxillary sinus elevation surgery. A total of 12 maxillary sinuses were grafted with an autogenous bone graft (control group) and 9 with ChronOS mixed with an autogenous bone graft (test group). Postoperative cone beam computed tomography (CBCT) was used to measure the initial graft volume after 15 days (T₁), and 6 months later another CBCT scan was performed to evaluate the final graft volume (T₂) and determine the graft resorption rate. The resorption outcomes were 45.7% ± 18.6% in the control group and 38.3% ± 16.6% in the test group (P = .17); the bone formation rate was 38.6% ± 10.5% in the control group and 25.4% ± 6.4% in the test group (P = .001). ChronOS mixed with autogenous bone graft demonstrated a resorption rate similar to that of the autogenous bone graft but with a difference in bone formation after 6 months.