COVID-19 patients display changes in lymphocyte subsets with a higher frequency of dysfunctional CD8lo T cells associated with disease severity.

This work examines cellular immunity against SARS-CoV-2 in patients from Córdoba, Argentina, during two major waves characterized by different circulating viral variants and different social behavior. Using flow cytometry, we evaluated the main lymphocyte populations of peripheral blood from hospitalized patients with moderate and severe COVID-19 disease. Our results show disturbances in the cellular immune compartment, as previously reported in different cohorts worldwide. We observed an increased frequency of B cells and a significant decrease in the frequency of CD3+ T cells in COVID-19 patients compared to healthy donors (HD). We also found a reduction in Tregs, which was more pronounced in severe patients. During the first wave, the frequency of GZMB, CD107a, CD39, and PD-1-expressing conventional CD4+ T (T conv) cells was significantly higher in moderate and severe patients than in HD. During the second wave, only the GZMB+ T conv cells of moderate and severe patients increased significantly. In addition, these patients showed a decreased frequency in IL-2-producing T conv cells. Interestingly, we identified two subsets of circulating CD8+ T cells with low and high CD8 surface expression in both HD and COVID-19 patients. While the percentages of CD8hi and CD8lo T cells within the CD8+ population in HD are similar, a significant increase was observed in CD8lo T cell frequency in COVID-19 patients. CD8lo T cell populations from HD as well as from SARS-CoV-2 infected patients exhibited lower frequencies of the effector cytokine-producing cells, TNF, IL-2, and IFN-γ, than CD8hi T cells. Interestingly, the frequency of CD8lo T cells increased with disease severity, suggesting that this parameter could be a potential marker for disease progression. Indeed, the CD8hi/CD8lo index helped to significantly improve the patient's clinical stratification and disease outcome prediction. Our data support the addition of, at least, a CD8hi/CD8lo index into the panel of biomarkers commonly used in clinical labs, since its determination may be a useful tool with impact on the therapeutic management of the patients.

Referral Patterns of General Dental Practitioners for Implant Surgery Procedures.

PURPOSE: The growing demand for implants has led to their implementation by general dental practitioners (GDPs) in clinical practice. The present study assessed referral patterns of GDPs for the surgical phase of implant dental treatment. MATERIALS AND METHODS: One hundred fifty GDPs were asked to fill out a structured questionnaire containing their demographic data and answer six questions characterising their referral patterns for implant dentistry. RESULTS: Forty-one (41%) percent performed the surgical phase, and 87% provided implant restoration. Gender was the only influencing factor for the surgical phase, as 51.4% of male GDPs and 6.5% of female GDPs performed implant surgery themselves. Experience and practice set-up did not influence the referring decision. Fifty-four percent of the practitioners referred 0 to 5 patients per month, and the chosen specialists were: 80% oral and maxillofacial surgeon, 11% periodontist, and 9% selected a specialist depending on the individual case. The major reasons influencing the referral pattern were the complexity of the surgical procedure, followed by systemic medical compromise of the patient. CONCLUSIONS: Most implant surgeries in Israel are still performed by specialists.

Effect of guided tissue regeneration on the success of surgical endodontic treatment of teeth with endodontic-periodontal lesions: A systematic review.

BACKGROUND: Endodontic-periodontal lesions may need surgical approach and the application of guided tissue regeneration (GTR) to be treated by a combined approach. OBJECTIVES: The aim of the present study was to evaluate the effects of GTR on the success (clinical and radiological healing) of teeth with endodontic-periodontal lesions treated by modern surgical endodontic treatment, by means of a systematic review of the literature. METHODS: An exhaustive electronic (Medline, Embase and Scopus searched from inception to August 2020) and manual literature search combined with strict inclusion and exclusion criteria was undertaken to identify any clinical (prospective case series or comparative trials) studies that assessed the added benefit of GTR in modern surgical endodontic treatment of teeth with endodontic-periodontal lesions. The success of the treatment was assessed based on radiographic healing and clinical evaluations. The risk of bias of the identified studies was evaluated using the Cochrane's collaboration RoB 2.0 tool and the Joanna Briggs Institute (JBI) critical appraisal tools. RESULTS: A systematic literature search for eligible reports retrieved three randomized controlled trials (RCTs) and one prospective single arm study with a total of 125 teeth in 125 subjects. One of the RCTs has a low risk of bias, while the other two raised some concerns, using the RoB 2.0 tool. Due to the heterogeneity of the results, it was not possible to perform a comparative meta-analysis and the results are presented in a narrative manner and by calculating pooled outcomes. Pooling together the data from all the included studies, the reported outcome was of complete healing in 58.4% of all cases, of scar tissue formation/incomplete healing in 24% of cases, of uncertain healing in 12.8% of cases, and of failure in 4.8% of all analysed teeth, with a follow-up ranging from 12 to 60 months. DISCUSSION: The scientific evidence about the use of GTR in modern surgical endodontic treatment of endodontic-periodontal lesion is sparse, and the available results are derived from very heterogeneous studies, thus not permitting to clarify which is the most effective treatment option in these cases. CONCLUSIONS: There is an absence of studies comparing GTR versus no GTR. REGISTRATION: The protocol for this review was registered in the PROSPERO database with the registration ID number CRD42022300470.

Different cytokine and chemokine profiles in hospitalized patients with COVID-19 during the first and second outbreaks from Argentina show no association with clinical comorbidities.

Background: COVID-19 severity has been linked to an increased production of inflammatory mediators called "cytokine storm". Available data is mainly restricted to the first international outbreak and reports highly variable results. This study compares demographic and clinical features of patients with COVID-19 from Córdoba, Argentina, during the first two waves of the pandemic and analyzes association between comorbidities and disease outcome with the "cytokine storm", offering added value to the field. Methods: We investigated serum concentration of thirteen soluble mediators, including cytokines and chemokines, in hospitalized patients with moderate and severe COVID-19, without previous rheumatic and autoimmune diseases, from the central region of Argentina during the first and second infection waves. Samples from healthy controls were also assayed. Clinical and biochemical parameters were collected. Results: Comparison between the two first COVID-19 waves in Argentina highlighted that patients recruited during the second wave were younger and showed less concurrent comorbidities than those from the first outbreak. We also recognized particularities in the signatures of systemic cytokines and chemokines in patients from both infection waves. We determined that concurrent pre-existing comorbidities did not have contribution to serum concentration of systemic cytokines and chemokines in COVID-19 patients. We also identified immunological and biochemical parameters associated to inflammation which can be used as prognostic markers. Thus, IL-6 concentration, C reactive protein level and platelet count allowed to discriminate between death and discharge in patients hospitalized with severe COVID-19 only during the first but not the second wave. Conclusions: Our data provide information that deepens our understanding of COVID-19 pathogenesis linking demographic features of a COVID-19 cohort with cytokines and chemokines systemic concentration, presence of comorbidities and different disease outcomes. Altogether, our findings provide information not only at local level by delineating inflammatory/anti-inflammatory response of patients but also at international level addressing the impact of comorbidities and the infection wave in the variability of cytokine and chemokine production upon SARS-CoV-2 infection.

The effect of imaging modality on the evaluation of the outcome of endodontic surgery.

OBJECTIVES: The aim of this study was to assess the effect of the imaging modality on the evaluation of the outcome of modern surgical endodontic treatments, based on a systematic review of the literature. METHODS: Strict inclusion criteria were adopted in order to identify studies that assessed the outcome of surgical endodontic treatments. Treatment success rates were pooled. The effect of the imaging modality used for the outcome assessment, and the methodological quality of the studies (based on the risk of bias (ROB)), were evaluated. RESULTS: Nineteen articles were included. The success rates assessed by periapical (PA) radiography were significantly higher than when cases were evaluated by cone beam computed tomography (CBCT; 90 and 35% respectively). This difference was mainly due to a significant proportion of cases that were assessed by CBCT as uncertain healing (48%) compared to only 4% using PA. The success rates ranged between 86 and 92% in low ROB studies, and between 19-100% in high ROB studies. CONCLUSIONS: Outcome assessment based on CBCT may lead to significantly lower estimates of rate of success, and higher rates of uncertain healing, thus presenting a dilemma in the decision-making following surgical endodontic treatment. The success rates of studies with lower methodological quality are more variable than for high quality studies.

Immediate versus Delayed Attachment Incorporation Impact on Prosthetic Aftercare among Mandibular Implant-Supported Overdenture Wearers.

BACKGROUND: Substantial effort is dedicated to finding the most favorable parameters that will ensure low aftercare demands among edentulous patients wearing mandibular implant supported overdentures (MISODs). The purpose of this retrospective cohort study was to compare prosthetic aftercare between MISOD patients with a simultaneous (group A) vs. a three-week settling in period (group B) prior to attachment incorporation. METHODS: Forty-five patients enrolled in this study. Two implants per patient were placed using a two-stage implant insertion protocol. Second-stage surgery was performed after three months. All patients received ball attachments using the direct (chairside) incorporation method. Twenty-two patients received their dentures with simultaneous attachment activation and the rest-twenty-three patients-after a three-week settling in period. Patients' files were scanned for aftercare visits. Outcome parameters included sore spot relief, attachment incorporation, and denture repair. Additionally, gingival index measurements were compared. Confounding factors included age, gender, and implant dimensions. RESULTS: The mean follow-up for the entire cohort was 84 ± 21 months, and the range 39-120 months. The mean number of visits for group A vs. B respectively: pressure sores relieve (3.63 ± 0.84 vs. 3.71 ± 0.61, p = 0.581), liner exchange due to loss of retention (2.09 ± 1.03 vs. 2.31 ± 1.04 p = 0.487), and gingival index (1.3 ± 0.3 vs. 1.03 ± 0.2, p = 0.653) exhibited no statistically significant differences between the tested groups. No statistically significant differences between the groups were also noted for the denture repair aftercare treatments (p = 0.318) and the independent variables including age, gender, and implant length. CONCLUSIONS: Prosthetic aftercare in MISOD wearers is similar whether a simultaneous or a three-week settling in period for attachment incorporation is applied.

Maxillary Tuberosity Fractures Following Third Molar Extraction, Prevalence, and Risk Factors.

OBJECTIVES: The aim of this study was to evaluate the prevalence of maxillary tuberosity fractures in an adult population and to examine the different risk factors associated with these fractures. MATERIALS AND METHODS: This is a retrospective study; data was collected from medical records of patients who underwent a non-surgical extraction of a maxillary third molar tooth between January 2017 and March 2019. All extractions were performed by 2 maxillofacial specialists. RESULTS: A total of 403 extracted maxillary third molar teeth were included in the study. Out of them 73 cases of tuberosity fractures were recorded (18.1%). No significant difference in the number of recorded fractures was found between the 2 surgeons. The mean age of patients was 32.8 ± 11.5. In the age group of 30 years and under a fractures rate of 12.1% was recorded compared to 25.0% in the age group of over 30 (P = 0.001). Divergent or extremely curved root morphology were associated with a higher risk for fractures (30.7%) compared to convergent root morphology (13.1%) ( P < 0.001). Borderline significance ( P = 0.069) was observed for extractions of teeth with caries lesions (21.9%) compared to teeth with no caries lesions (14.6%). CONCLUSIONS: The risk of developing a tuberosity fracture during an extraction of an upper wisdom tooth increases with age by 3.1% per year. Teeth with a caries lesion or teeth with divergent or extremely curved root morphology are associated with a higher risk for tuberosity fractures. Although, distoangular teeth had reduced risk of developing a tuberosity fractures. Data collected in this study may help to evaluate the risk factors associated with tuberosity fractures, and can assist in minimizing complications during extractions.

A thermosensitive gel with an active hyaluronic acid ingredient that contains an octenidine preservation system as an adjunct to scaling and root planning: a randomized prospective clinical study.

OBJECTIVES: To evaluate the adjunctive effect of a thermosensitive gel formulation that contains 0.8% oligo hyaluronic acid (HA) combined with a preservation system of octenidine HCl 0.625% and phenoxyethanol to scaling and root planing (SRP) as compared with SRP alone in the treatment of residual pockets of patients with stage 3 periodontitis. MATERIALS AND METHODS: Thirty-four patients (21 males and 13 females) aged 29-78 years (51.3 ± 13.1) with stage 3 periodontitis were recruited to participate in the present split-mouth study. None of the patients has been previously treated for periodontitis. Plaque index (PI), probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were evaluated at baseline and at 3 and 6 months post treatment. Full-mouth SRP was performed in all residual pockets ≥ 5 mm. Treatment was performed by means of ultrasonic and hand instruments and lasted 45-60 min. The gel was applied subgingivally in the test sites immediately after SRP (baseline) and 1 month later. The paired t-test for two means was applied to test the statistical significance of the change from baseline within each arm and determine the difference between groups. The level of significance was set at 0.05 for all tests. RESULTS: Mean PD reductions between baseline and 3 and 6 months were 1.98 mm and 2.79 mm for the test and 1.22 mm and 1.50 mm for the control group, respectively. Comparisons between the test and control groups revealed that SRP + gel yielded statistically significantly higher PD reductions compared to SRP alone (p < 0.0001). Compared to baseline, CAL and BOP values improved statistically significantly in both groups, although the test group presented statistically significantly higher CAL gains and BOP reductions than the control group (P < 0.0001). CONCLUSION: In residual pockets of stage 3 periodontitis patients, the local application of a thermosensitive gel with an active HA ingredient and a preservation system of octenidine HCl 0.625% in conjunction with SRP may additionally improve the clinical outcomes obtained with SRP alone. CLINICAL RELEVANCE: A novel HA and octenidine containing thermosensitive gel effectively improved the clinical parameters in stage 3 periodontitis patients over a 6-month period.

Factors affecting the decision to rehabilitate the posterior maxilla following surgical closure of oroantral communications/fistulae - A cohort study.

BACKGROUND: Search of the English literature yielded no studies assessing the chosen dental treatment following surgical closure of oroantral communication/oroantral fistula (OAC/OAF). The purpose of the present study was to assess factors affecting the decision to rehabilitate the posterior maxilla following surgical closure of OAC/OAF. METHODS: Consecutive patients at a single center. A structured form served to collect the data. The differences between groups (cases with versus cases without restoration) were assessed statistically. RESULTS: A total of 58/121 responding individuals (62.1% men). Average age 51.57 years. Average waiting time prior to restoration 10.34 months. Most (51.7%) healthy. Most had a dental etiology (60.3%). Thirty-nine (67.2%) patients had a restoration of the posterior maxilla. Most of the patients responded that the reason not to do any restoration is the fear of failure (65.5%). Most of the patients completed the restoration procedure in a private clinic (87.2%). Only one patient (2.6%) reported a complication. Approximately half of the patients had implant supported prosthesis (ISP) following sinus augmentation (48.3%) with delayed implant placement. Most of the patients responded that the reason not to have ISP was the fear of failure (72.7%), and the rest responded because of financial issues (27.3%). For tooth supported restoration, most of the patients responded removable (90.9%). CONCLUSIONS: Surgeons generally wait 6-12 months following surgical treatment of OAC/OAF prior to reconstruction with ISP. The chance for complications is low. Healthy women after dental induced OAC/OAF have the highest chances to seek for ISP in such circumstances.

Patients' Perception of Recovery after Dental Implant Placement.

Background and Objectives: The success rates of surgical dental implant insertions are high. However, knowledge of patients' recovery is still lacking. "Health-related quality of life" (HRQOL) questionnaires are gaining popularity in all fields of medicine. The present survey assessed the perception of recovery after the surgical placement of dental implants. Materials and Methods: Forty individuals (26 women and 14 men; mean age, 55 ± 12 years) filled a questionnaire evaluating patients' perception of recovery for 7 consecutive days post-surgery. Confounding factors included age, gender, oral habits, smoking, bruxism, bone quality (tactile evaluation) and quantity, implant location, number of implants, implant type, length and diameter, one-stage vs. two-stage, and the need for bone grafting. Results: The most serious difficulties were found in swelling, which became minimal after 5 days, followed by eating everyday food, ability to enjoy everyday food, maximal pain and average pain (3 days); analgesics consumption (2.5 days); limitations in daily routine, mouth opening, and speech (2 days); swallowing and sleep (1.5 days); and, within 1 day, all other measures attained minimal levels. Gender, and implant location (anterior vs. posterior) were significant predictor variables exerting their different characteristic delayed recoveries. Conclusions: (1) Patients should expect, in general, recovery within 4 days after dental implant placement; (2) women will experience a delayed recovery, (3) implants placed in the intercanine area will result in postoperative eating difficulties for nearly one week, and (4) the number of implants placed during the same appointment has no effect on post treatment recovery.

Automatic detection of image sharpening in maxillofacial radiology.

BACKGROUND: Improvement of image quality in radiology, including the maxillofacial region, is important for diagnosis by enhancing the visual perception of the original image. One of the most used modification methods is sharpening, in which simultaneously with the improvement, due to edge enhancement, several artifacts appear. These might lead to misdiagnosis and, as a consequence, to improper treatment. The purpose of this study was to prove the feasibility and effectiveness of automatic sharpening detection based on neural networks. METHODS: The in-house created dataset contained 4290 X-ray slices from different datasets of cone beam computed tomography images were taken on 2 different devices: Ortophos 3D SL (Sirona Dental Systems GmbH, Bensheim, Germany) and Planmeca ProMax 3D (Planmeca, Helsinki, Finland). The selected slices were modified using the sharpening filter available in the software RadiAnt Dicom Viewer software (Medixant, Poland), version 5.5. The neural network known as "ResNet-50" was used, which has been previously trained on the ImageNet dataset. The input images and their corresponding sharpening maps were used to train the network. For the implementation, Keras with Tensorflow backend was used. The model was trained using NVIDIA GeForce GTX 1080 Ti GPU. Receiver Operating Characteristic (ROC) analysis was performed to calculate the detection accuracy using MedCalc Statistical Software version 14.8.1 (MedCalc Software Ltd, Ostend, Belgium). The study was approved by the Ethical Committee. RESULTS: For the test, 1200 different images with the filter and without modification were used. An analysis of the detection of three different levels of sharpening (1, 2, 3) showed sensitivity of 53%, 93.33%, 93% and specificity of 72.33%, 84%, 85.33%, respectively with an accuracy of 62.17%, 88.67% and 89% (p < 0.0001). The ROC analysis in all tests showed an Area Under Curve (AUC) different from 0.5 (null hypothesis). CONCLUSIONS: This study showed a high performance in automatic sharpening detection of radiological images based on neural network technology. Further investigation of these capabilities, including their application to different types of radiological images, will significantly improve the level of diagnosis and appropriate treatment.

Oral lichen planus and thyroid gland diseases: possible associations.

BACKGROUND: Lichen planus (LP) is a chronic inflammatory mucocutaneous disease that commonly affects the oral cavity. Previous reports have suggested a possible association between LP and thyroid gland diseases (TGDs). The purpose of this study was to investigate possible associations between oral lichen planus (OLP) and TGDs. METHODS: Patients diagnosed with OLP, both clinically and histopathologically (N = 102), were classified according to clinical course (symptomatic/asymptomatic), type (reticular/plaque, atrophic and erosive) and location of lesions. Data on TGDs was compared to age- and gender-matched controls (N = 102) without OLP. Diagnosis of any type of TGD and related medication for study and control groups was recorded from the medical files provided by patients' physicians. Statistical analysis used Student's t-test and Fisher's exact test; significance was set at p < 0.05. RESULTS: TGDs (all), hypothyroidism and related medications were found in 16.6, 12.7 and 12.7% of patients with OLP, respectively. These findings were similar to the control group: TGDs (all) -15.7%, hypothyroidism - 9.8% and thyroid gland disease-related medication - 9.8% (p > 0.05). No significant associations were found between different characteristics of OLP and hypothyroidism or other TGD (p > 0.05). CONCLUSIONS: We found no significant associations between the co-existence of OLP and TGD or related-medications. Our findings are in agreement with some of the previously published similar studies but in controversy with others. Further well-designed, multicenter studies with large groups of patients and controls may help to establish the nature of the associations between OLP and TGDs.

Advances in Porous Scaffold Design for Bone and Cartilage Tissue Engineering and Regeneration.

IMPACT STATEMENT: Challenges in musculoskeletal tissue regeneration affect millions of patients globally. Scaffolds for tissue engineering bone and cartilage provide promising solutions that increase healing and decrease need for complicated surgical procedures. Porous scaffolds have emerged as an attractive alternative to traditional scaffolds. However, the success of advanced materials, use of biological factors, and manufacturing techniques can vary depending on use case. This review provides perspective on porous scaffold manufacturing, characterization and application, and can be used to inform future scaffold design.

Laser Sintered Porous Ti-6Al-4V Implants Stimulate Vertical Bone Growth.

The objective of this study was to examine the ability of 3D implants with trabecular-bone-inspired porosity and micro-/nano-rough surfaces to enhance vertical bone ingrowth. Porous Ti-6Al-4V constructs were fabricated via laser-sintering and processed to obtain micro-/nano-rough surfaces. Male and female human osteoblasts were seeded on constructs to analyze cell morphology and response. Implants were then placed on rat calvaria for 10 weeks to assess vertical bone ingrowth, mechanical stability and osseointegration. All osteoblasts showed higher levels of osteocalcin, osteoprotegerin, vascular endothelial growth factor and bone morphogenetic protein 2 on porous constructs compared to solid laser-sintered controls. Porous implants placed in vivo resulted in an average of 3.1 ± 0.6 mm3 vertical bone growth and osseointegration within implant pores and had significantly higher pull-out strength values than solid implants. New bone formation and pull-out strength was not improved with the addition of demineralized bone matrix putty. Scanning electron images and histological results corroborated vertical bone growth. This study indicates that Ti-6Al-4V implants fabricated by additive manufacturing to have porosity based on trabecular bone and post-build processing to have micro-/nano-surface roughness can support vertical bone growth in vivo, and suggests that these implants may be used clinically to increase osseointegration in challenging patient cases.

Age and Expression of CD163 and Colony-Stimulating Factor 1 Receptor (CD115) Are Associated With the Biological Behavior of Central Giant Cell Granuloma.

PURPOSE: Central giant cell granulomas (CGCGs) are clinically classified as nonaggressive (nA-CGCGs) and aggressive (A-CGCGs). However, histopathologically, all lesions feature spindle mononuclear cells (MCs) and multinuclear giant cells (GCs) in a hemorrhage-rich stroma. We aimed to investigate the presence of cells with a monocyte- or macrophage-related phenotype and, together with clinical variables, to examine their predictive potential for the biological behavior of CGCGs. PATIENTS AND METHODS: For our investigation, we implemented a retrospective cohort study. Sections were immunohistochemically stained for colony-stimulating factor 1 receptor (CSF-1R) (CD115), CD163, CD68, and nuclear factor κB. The clinical variables included age, gender, and location of lesions. Associations between immunostains, clinical variables, and CGCG aggressiveness were analyzed by the Wilcoxon (Mann-Whitney) exact test and t test. Significant variables were further analyzed by a logistic regression model followed by receiver operating characteristic (ROC) curve analysis for diagnostic sensitivity. Significance was set at P < .05. RESULTS: Patients with A-CGCGs (n = 36) were younger than those with nA-CGCGs (n = 31) (P = .002). Logistic regression showed that CD163-GC (ß = -0.870, P = .031) and CD115-MC (ß = -0.783, P = .027) had a significant protection effect (odds ratio, 0.419 [95% confidence interval, 0.190 to 0.925], and odds ratio, 0.457 [95% confidence interval, 0.229 to 0.913], respectively). ROC curve analysis showed that CD163-GC and CSF-1R (CD115)-MC combined were the best predictor in distinguishing nA-CGCGs from A-CGCGs (area under ROC curve, 0.814; P < .001). At the optimal cutoff value (0.408), sensitivity was 87% and specificity, 65%. CONCLUSIONS: Increasing age and high expression of CD163-GC and CSF-1R (CD115)-MC can serve as significant predictors of nA-CGCGs. A functional link between CD163-GC and the characteristic areas of extravasation of erythrocytes is discussed.

Inmunodeficiencia común variable: correlación entre parámetros inmunológicos y manifestaciones clínicas

La inmunodeficiencia común variable(IDCV) es una inmunodeficiencia humoral primaria caracterizada por la disminución de inmunoglobulina G y al menos otra inmunoglobulina, la presencia de infecciones recurrentes y complicaciones no infecciosas como enfermedades autoinmunes, linfoproliferativas o neoplásicas

Summary: Common variable immunodeficiency is a humoral primary immunodeficiency characterized by low LgG levels and of at least another immunoglobulin, recurrent infections, and moninfectious complications, as autoimmune, lymphoproliferative or neoplastic diseases

Maxillary Sinus Grafting with Autograft Versus Fresh-Frozen Allograft: A Split-Mouth Evaluation of Bone Volume Dynamics.

PURPOSE: To compare volumetric changes after sinus augmentation of completely edentulous maxillae with either autogenous or allogeneic fresh-frozen bone particles. MATERIALS AND METHODS: This split-mouth study in patients who required bilateral sinus grafting used autograft particles for one sinus and allograft particles for the contralateral sinus. The grafted sinuses were left to heal for 6 months prior to implant insertion. All patients underwent four computed tomography scans: prior to augmentation and 1 week, 6 months, and 12 months after grafting. Computer software was used to analyze bone graft volume in each scan. RESULTS: Fifteen patients (8 men, 7 women) with a mean age of 54 ± 5 years (range, 48 to 60 years) took part and underwent 30 sinus augmentation procedures. Mean autograft and allograft volumes were not statistically significantly different at each time point (1 week: 2.01 ± 0.43 cm³ vs 2.46 ± 0.79 cm³; 6 months: 1.53 ± 0.49 cm³ vs 1.75 ± 0.64 cm³; and 12 months: 1.38 ± 0.43 cm³ vs 1.59 ± 0.56 cm³, respectively). Mean volumetric reductions of 31.35% and 35.36% (23.9% and 29.9% in the 6 months prior to implant insertion, followed by an additional 9% and 9% in the following 6 months), relative to 1 week postgrafting, were noted for the autograft and allograft groups, respectively, after 12 months. CONCLUSION: On the basis of this split-mouth study of 15 patients, there was no statistically significant volumetric difference after 12 months between the use of autograft or allografts for sinus augmentation. Fresh-frozen bone allograft may serve as an alternative that avoids the morbidity associated with autograft harvesting.

Maxillary sinus grafting with autograft vs. fresh frozen allograft: a split-mouth histomorphometric study.

BACKGROUND: Surgical techniques as sinus floor augmentation have made it possible to increase the bone volume of the posterior maxilla so that implant placement may be feasible. A large variety of bone grafting materials have been utilized for sinus floor augmentation. A good alternative is allograft. Fresh frozen bone is harvested from live or cadaveric donors and then immediately frozen and stored at -80 °C. To date, studies about the effect of fresh frozen bone are scarce. OBJECTIVE: Evaluation of new bone formation, following maxillary sinus grafting with autograft vs. fresh frozen allograft. MATERIALS AND METHODS: A split-mouth edentulous design including 15 patients was used. Sinus floor augmentation was carried out using either autogenous bone harvested from the ramus area or fresh frozen bone from allogeneic femoral heads. The choice was determined randomly, using a randomized table. The grafted sinus was left to heal for 6 months. Biopsies were harvested from the lateral wall. The biopsies were used for bone histology and histomorphometric analysis. After collection of the biopsy, dental implants were placed. After a healing period of 6 months, the implants were loaded. RESULTS: Implant survival, histology, and histomorphometry of sinuses grafted with autogenous or fresh frozen bone were similar. The new bone formation took place predominantly around and in-between particles. CONCLUSIONS: The findings of the present study support the use of fresh frozen bone allografts for sinus floor augmentation.