Search

Abstract A postmortem evaluation of a 5-implant–supported mandibular fixed complete denture that had successfully opposed a maxillary conventional complete denture for 30 years was undertaken. Before embalming, radiographs, implant stability measurements, push-in failure load tests, and histomorphometric analyses were performed on the implants and the mandible. Evaluation of this cadaver suggests that an edentulous mandible restored with an implant-supported fixed prosthesis can function successfully for over 30 years with few complications. [ABSTRACT FROM AUTHOR]

Abstract: Background: Recombinant human bone morphogenetic protein‐2 in an absorbable collagen sponge carrier (rhBMP‐2/ACS) has been shown to support significant bone formation when used to augment the maxillary sinus for implant dentistry. Nevertheless, bone biomaterials have been suggested to extend rhBMP‐2/ACS with limited support of the merits of such approaches. Objectives: To evaluate local bone formation/dental implant osseointegration following implantation of rhBMP‐2/ACS combined with a ceramic bone biomaterial using a mini‐pig sinus augmentation model. Methods: Twelve adult Göttingen mini‐pigs received rhBMP‐2/ACS (rhBMP‐2 adjusted to 0.43 mg/cc) alone or combined with an off‐the‐shelf biphasic ceramic (15%/85% HA/ß‐TCP) biomaterial at 3:1, 1:1 and 1:3 ratios randomized to contra‐lateral maxillary sinus sites yielding rhBMP‐2/ACS fractions of 100%, 75%, 50% and 25%, respectively. A 4‐cc implant volume was used for all sites. Two threaded dental implants (ø4.0 × 11.5 mm) were placed at each site. The animals were euthanized at 8 weeks for histologic analysis. Results: Surgical execution and healing were generally uneventful, infraorbital local swelling was observed in all animals until suture removal. rhBMP‐2/ACS combined with the ceramic biomaterial did not significantly enhance local bone formation (range 9.0 ± 1.5 to 9.7 ± 2.1 mm) compared with rhBMP‐2/ACS alone (8.6 ± 1.1 mm; p > 0.05). Variations in rhBMP‐2/ACS to ceramic matrix ratios yielding rhBMP‐2 doses approximating 0.4, 0.9, 1.3 and 1.7 mg/sinus did not appreciably influence bone formation/osseointegration. Conclusions: Whereas rhBMP‐2/ACS supports significant bone formation/osseointegration in the mini‐pig sinus augmentation model and thus appears an effective alternative for sinus augmentation procedures, adding a ceramic biomaterial to rhBMP‐2/ACS does not produce meaningful biological advantages. [ABSTRACT FROM AUTHOR]

Understanding what determines species’ geographic distributions is crucial for assessing global change threats to biodiversity. Measuring limits on distributions is usually, and necessarily, done with data at large geographic extents and coarse spatial resolution. However, survival of individuals is determined by processes that happen at small spatial scales. The relative abundance of coexisting species (i.e. ‘community structure’) reflects assembly processes occurring at small scales, and are often available for relatively extensive areas, so could be useful for explaining species distributions. We demonstrate that Bayesian Network Inference (BNI) can overcome several challenges to including community structure into studies of species distributions, despite having been little used to date. We hypothesized that the relative abundance of coexisting species can improve predictions of species distributions. In 1570 assemblages of 68 Mediterranean woody plant species we used BNI to incorporate community structure into Species Distribution Models (SDMs), alongside environmental information. Information on species associations improved SDM predictions of community structure and species distributions moderately, though for some habitat specialists the deviance explained increased by up to 15%. We demonstrate that most species associations (95%) were positive and occurred between species with ecologically similar traits. This suggests that SDM improvement could be because species co-occurrences are a proxy for local ecological processes. Our study shows that Bayesian Networks, when interpreted carefully, can be used to include local conditions into measurements of species’ large-scale distributions, and this information can improve the predictions of species distributions. [ABSTRACT FROM AUTHOR]

The pH of the endolysosomal system is tightly regulated by a balance of proton pump and leak mechanisms that are critical for storage, recycling, turnover, and signaling functions in the cell. Dysregulation of endolysosomal pH has been linked to aging, amyloidogenesis, synaptic dysfunction, and various neurodegenerative disorders, including Alzheimer's disease. Therefore, understanding the mechanisms that regulate luminal pH may be key to identifying new targets for managing these disorders. Meta-analysis of yeast microarray databases revealed that nutrient-limiting conditions inhibited the histone deacetylase (HDAC) Rpd3 and thereby up-regulated transcription of the endosomal Na+/H+ exchanger Nhx1, resulting in vacuolar alkalinization. Consistent with these findings, Rpd3 inhibition by the HDAC inhibitor and antifungal drug trichostatin A induced Nhx1 expression and vacuolar alkalinization. Bioinformatics analysis of Drosophila and mouse databases revealed that caloric control of the Nhx1 orthologs DmNHE3 and NHE6, respectively, is also mediated by HDACs. We show that NHE6 is a target of the transcription factor cAMP-response element- binding protein (CREB), a known regulator of cellular responses to low-nutrient conditions, providing a molecular mechanism for nutrient- and HDAC-dependent regulation of endosomal pH. Of note, pharmacological targeting of the CREB pathway to increase NHE6 expression helped regulate endosomal pH and correct defective clearance of amyloid Aβ in an apoE4 astrocyte model of Alzheimer's disease. These observations from yeast, fly, mouse, and cell culture models point to an evolutionarily conserved mechanism for HDAC-mediated regulation of endosomalNHEexpression. Our insights offer new therapeutic strategies for modulation of endolysosomal pH in fungal infection and human disease. [ABSTRACT FROM AUTHOR]

PURPOSE: The purpose of the study was to evaluate the long-term efficacy and safety of intravitreal bevacizumab (IVB) in the treatment of choroidal neovascularization (CNV) secondary to angioid streaks (AS). MATERIALS AND METHODS: Noncomparative, interventional retrospective case series involving ten patients (15 eyes) with a minimum follow-up of 25 months following IVB for AS-associated CNV. Demographic and clinical details at baseline and during follow-up were collected from patient records. Detailed clinical examination was followed by fundus fluorescein angiography and optical coherence tomography to confirm CNV. Both primary and recurrent CNVs were treated with monthly injections of IVB till the lesion stabilized. Primary outcome measures were the percentage of patients with stable or improved visual acuity (VA) and with stable or decreased central retinal thickness (CRT) at the last visit. Secondary outcome measure was the incidence of ocular and systemic complications. RESULTS: Recurrence was observed in 11 eyes (73.33%) over a mean follow-up of 57.33 months (range: 25-100). A mean number of injections administered was 5.60. VA improved or stabilized in 73.33% and deteriorated in 26.67% of eyes at the final visit. Mean CRT improved from 324.40 µm at baseline to 265.53 µm at final visit, which was statistically significant. Complications observed were ocular hypertension in one patient and thromboembolic event in another patient. CONCLUSIONS: IVB appears to be a safe and effective option to treat CNV and to preserve vision over a prolonged period. It cannot eliminate the risk of recurrent CNV indicating the need for more effective treatments to arrest this visually debilitating condition. [ABSTRACT FROM AUTHOR]

Keywords: cascade; Dowd-Beckwith reaction; radical chemistry; rearrangements; total synthesis EN cascade Dowd-Beckwith reaction radical chemistry rearrangements total synthesis 1 1 1 11/04/22 20221102 NES 221102 B Ring-expansion strategies b are valuable synthetic tools that take benefit of existing ring structures and evade the unfavorable enthalpic-and entropic effects that arise with end-to-end cyclizations. In their Review article (DOI: 10.1002/chem.202202025), Hari et al. discuss the origin and advancement of the Dowd-Beckwith reaction with particular focus on its application to complex natural products synthesis. Cascade, Dowd-Beckwith reaction, radical chemistry, rearrangements, total synthesis. [Extracted from the article]

Dental implants are widely accepted as the golden standard for the rehabilitation of an edentulous site following the extraction of a tooth. The ideal time for implant placement is dependent on the time required for partial or complete tissue healing and the adequacy of socket dimensions. The use of autologous growth factors is a promising new concept that aids clinicians in minimizing treatment time and increasing patient satisfaction. The purpose of this paper is to introduce a protocol for "accelerated-early" implant placement. In this protocol, platelet rich fibrin is employed to accelerate soft and hard tissue healing and to provide a better-healed recipient site for accelerated, early implant placement. Histological analysis revealed that at 6 weeks postextraction, the application of our approach resulted in delicate newly formed bone showing intense osteoblastic activity surrounded by connective tissue as well as areas of mineralized tissue. The present study is a proof-of-principle study of the acceleration of the physiologic postextraction healing sequelae with the use of autologous growth factors. The accelerated-early implant placement concept is a bioengineered protocol that may aid clinicians to achieve increased primary stability, by placing implants in ridges in an advanced stage of bone healing, while offering patients the benefits associated with early implant placement. Controlled studies are warranted to verify the reproducibility of this treatment concept and identify specific indications where the use of the presented technique can lead to significant clinical results. [ABSTRACT FROM AUTHOR]

In this study, we present a highly efficient method for proteomic profiling of cysteine residues in complex proteomes and in living cells. Our method is based on alkynylation of cysteines in complex proteomes using a 'clickable' alkynyl benziodoxolone bearing an azide group. This reaction proceeds fast, under mild physiological conditions, and with a very high degree of chemoselectivity. The formed azide-capped alkynyl-cysteine adducts are readily detectable by LC-MS/MS, and can be further functionalized with TAMRA or biotin alkyne via CuAAC. We demonstrate the utility of alkynyl benziodoxolones for chemical proteomics applications by identifying the proteomic targets of curcumin, a diarylheptanoid natural product that was and still is part of multiple human clinical trials as anticancer agent. Our results demonstrate that curcumin covalently modifies several key players of cellular signaling and metabolism, most notably the enzyme casein kinase I gamma. We anticipate that this new method for cysteine profiling will find broad application in chemical proteomics and drug discovery. [ABSTRACT FROM AUTHOR]

Background: Complete cast crowns are good alternatives and have best longevity for the restoration of damaged posterior teeth. Occasionally, a crown with clinically acceptable margins, preparation design, and occlusion becomes loose. Providers often debate whether such a crown can be successfully recemented with any degree of confidence that it will not be dislodged under normal masticatory function. It has been documented that resistance form increases by placing grooves opposing each other in a crown and tooth; cements also have a role to play in retention of crowns. To determine whether the addition of horizontal groove in the internal surface of the crown and/or tooth preparation will increase retention of the crowns, without remaking them and achieving better retention with cements. Materials and Methods: A total of 80 extracted human mandibular molars were taken and standard preparation was done. After the crowns were ready, the groove was made in the internal surface of the crown and on the tooth, which were cemented with glass ionomer cement and resin cement. The tensile force needed to dislodge the crowns and teeth after cementation was found out. Result: The mean tensile force needed to dislodge the crown and tooth combination was highest for the group in which crown had a groove without any groove on the tooth and cemented using resin cement (252.60N). Conclusion: It can be concluded from the study that it is best to recement a crown and tooth combination using resin cement where the crown has a groove, and the tooth has no groove. [ABSTRACT FROM AUTHOR]

Visible light and eosin Y catalyze the synthesis of vinyl sulfones from aryl sulfinates and alkenes by a photoredox process. The reaction scope is broad in aryl sulfinates and alkenes and the general and simple procedure provides a metal-free alternative for the synthesis of synthetically valuable vinyl sulfones. [ABSTRACT FROM AUTHOR]

Following tooth extraction, ridge preservation procedures are employed to regenerate bone in the extraction socket, limit consequent ridge resorption, and provide a stable base for implant placement. The purpose of this study is to histologically evaluate and compare bone regeneration in extraction sockets grafted with either a putty alloplastic bone substitute or particulate anorganic bovine xenograft utilizing the socket-plug technique. Nineteen patients underwent 20 tooth extractions and ridge preservation following a standardized protocol. Ten sites were grafted with calcium phosphosilicate putty (CPS group) and the remaining 10 with anorganic bovine bone substitute (BO group). Patients were recalled after 4-6 months to evaluate the bone regeneration and to proceed with implant placement. A bone core was obtained during the implant procedure from each site and was used for histologic analysis. Histomorphometry revealed that residual graft values were significantly higher in the BO group (25.60% ± 5.89%) compared to the CPS group (17.40% ± 9.39%) (P < .05). The amount of new bone regenerated was also statistically significant higher in the alloplast group (47.15% ± 8.5%) as compared to the xenograft group (22.2% ± 3.5%) (P < .05). Results suggest that ridge preservation using a putty calcium phosphosilicate alloplastic bone substitute demonstrates more timely graft substitution and increased bone regeneration when compared to an anorganic bovine bone xenograft. [ABSTRACT FROM AUTHOR]

Early intervention may be key to safe and effective therapies in patients with Alzheimer disease. Endosomal dysfunction is an early step in neurodegeneration. Endosomes are a major site of production of Aβ peptide from the processing of amyloid precursor protein (APP) by clipping enzymes (β- and γ-secretases). The β-secretase enzyme BACE1 requires acidic lumen pH for optimum function, and acid pH promotes Aβ aggregation. The Na+/H+ exchanger NHE6 provides a leak pathway for protons, limiting luminal acidification by proton pumps. Like APP, NHE6 expression was induced upon differentiation of SH-SY5Y neuroblastoma cells and localized to an endosomal compartment. Therefore, we investigated whether NHE6 expression altered APP localization and processing in a stably transfected cell culture model of human APP expression. We show that coexpression with NHE6 or treatment with the Na+/H+ ionophore monensin shifted APP away from the trans-Golgi network into early and recycling endosomes in HEK293 cells. NHE6 alkalinized the endosomal lumen, similar to monensin, and significantly attenuated APP processing and Aβ secretion. In contrast, Aβ production was elevated upon NHE6 knockdown. Weshow thatNHE6transcript and protein levels are lowered in Alzheimer brains relative to control. These findings, taken together with emerging genetic evidence linking endosomal Na+/H+ exchangers with Alzheimer disease, suggest that proton leak pathways may regulate Aβ generation and contribute to disease etiology. [ABSTRACT FROM AUTHOR]

It has been documented that after every extraction of one or more teeth, the alveolar bone of the respective region undergoes resorption and atrophy. Therefore, ridge preservation techniques are often employed after tooth extraction to limit this phenomenon. The benefits of a flapless procedure include maintenance of the buccal keratinized gingiva, prevention of alterations to the gingival contours, and migration of the mucogingival junction that are often experienced after raising a flap. The purpose of this article is to review the literature concerning flapless ridge preservation techniques with the aid of collagen plugs for occlusion of the socket. The term "socket-plug" technique is introduced to describe these techniques. The basic steps of the "socket-plug" technique consist of atraumatic tooth extraction, placement of the appropriate biomaterials in the extraction site, preservation of soft tissue architecture employing a flapless technique, and placement and stabilization of the collagen plug. A case example is presented that illustrates the steps used in this technique. [ABSTRACT FROM AUTHOR]

In the 100-year history of bone replacement in the human body for different purposes, a wide variety of surgical approaches and materials have been used. The techniques and materials selected significantly affect the outcome of bone replacement procedures in terms of bone formation volume and the quality and amount of vital bone. The choices facing the dental surgeon at the time of extraction, ridge augmentation, or sinus graft are wide-ranging. When choosing a bone graft material the surgeon should consider its ultimate effect on healing patterns in and around the alveolar bone at the endpoint of the procedure. As this article concludes, a better understanding of the materials and the results that can be predictably achieved with them can be valuable to the appropriately trained surgeon when preparing for these procedures. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the effects of a modified implant abutment design on peri-implant soft and hard tissues in dogs. Three months after extraction of mandibular premolar teeth, 3 dental implants were placed in each side of the jaw using a 1-stage approach. Implants on one side of the mandible received standard abutments (control), and implants on the contralateral side received modified, patented, grooved abutments (test). Two months after implant placement, animals were euthanized and specimens were prepared for histologic and histomorphometric assessment. The linear distance (in micrometers) was measured from the implant shoulder (IS) to the following landmarks: gingival margin (GM; distance IS-GM), most apical position of the junctional epithelium (JE; distance IS-JE), and bone crest (BC; distance IS-BC). Percent of bone-to-implant contact was also measured. Histologic assessment revealed that all implants were osseointegrated and that interimplant gingival fibers between test abutments appeared to be more numerous and organized than control abutments. The IS-GM and IS-JE distances in test implants were greater than the corresponding distances in control implants (P = .024 and P = .015, respectively), whereas crestal bone loss (IS-BC) was greater for control implants than test implants (P = .037). There were no differences between control and test implants in bone-to-implant contact (P = .69), which averaged close to 50%. These results suggest that the modified groove design incorporated in standard abutments confers both soft and hard tissue benefits. [ABSTRACT FROM AUTHOR]

Autism imposes a major impediment to childhood development and a huge emotional and financial burden on society. In recent years, there has been rapidly accumulating genetic evidence that links the eNHE, a subset of Na+/H+ exchangers that localize to intracellular vesicles, to a variety of neurological conditions including autism, attention deficit hyperactivity disorder (ADHD), intellectual disability, and epilepsy. By providing a leak pathway for protons pumped by the V-ATPase, eNHE determine luminal pH and regulate cation (Na+, K+) content in early and recycling endosomal compartments. Loss-of-function mutations in eNHE cause hyperacidification of endosomal lumen, as a result of imbalance in pump and leak pathways. Two isoforms, NHE6 and NHE9 are highly expressed in brain, including hippocampus and cortex. Here, we summarize evidence for the importance of luminal cation content and pH on processing, delivery and fate of cargo. Drawing upon insights from model organisms and mammalian cells we show how eNHE affect surface expression and function of membrane receptors and neurotransmitter transporters. These studies lead to cellular models of eNHE activity in pre- and post-synaptic neurons and astrocytes, where they could impact synapse development and plasticity. The study of eNHE has provided new insight on the mechanism of autism and other debilitating neurological disorders and opened up new possibilities for therapeutic intervention. [ABSTRACT FROM AUTHOR]

Introduction: To preserve alveolar bone after extractions, it is important to graft socket sites to prevent bone loss from repair and remodeling. Objective: The objective of this case series was to assess the clinical, densitometric, and histomorphometric results from extraction sockets treated with recombinant human bone morphogenetic protein (rhBMP-2/ACS). Study Design: After extraction and socket debridement, INFUSE (rhBMP-2) on absorbable sponges was placed over each socket. After 4 months, 3-dimensional cone-beam computerized tomographic (CT) scans were taken. Trephined bone cores were taken as the first step in the implant site osteotomy and submitted for histomorphometric analysis. Results: Histomorphometric analysis showed a mean of 49.6% vital bone with a SD of 10.8%. CT scans showed mean density of 510.6 Hounsfield units. Conclusions: Use of INFUSE in socket preservation surgery results in adequate de novo bone formation to support ideal implant placement after 4 months. [ABSTRACT FROM AUTHOR]

Eine Vielzahl von Amiden ist unter milden Bedingungen durch intermolekulare Aminoarylierung unter Verwendung einer photokatalytischen Meerwein ‐ Addition mit sichtbarem Licht erhältlich. Das Syntheseprotokoll erlaubt einen breiten Substratbereich, toleriert eine Bandbreite von funktionellen Gruppen und wurde auf die Synthese eines Isochinolidalkaloids angewendet. Von der Eliminierung zur Addition: Die intermolekulare Aminoarylierung von Alkenen bietet einen effizienten Zugang zu vielfältigen Amiden. Die milden Bedingungen der Photo ‐ Meerwein ‐ Addition mit sichtbarem Licht erlauben eine große Substratbreite und eine gute Toleranz gegenüber vielen funktionellen Gruppen. [ABSTRACT FROM AUTHOR]

A variety of amides are efficiently accessible under mild conditions by intermolecular amino-arylation using a photo Meerwein addition with visible light. The reaction has a broad substrate scope, tolerates a large range of functional groups, and was applied to the synthesis of a 3-aryl-3,4-dihydroisoquinoline. [ABSTRACT FROM AUTHOR]

Background: Chinese hamster ovary (CHO) ceil-derived recombinant human bone morphogenetic protein-2 (rhBMP-2) has been introduced for spine, long bone, and craniofacial indications. Escherichia coli- (E. coli) derived rhBMP-2 displays comparable efficacy to CHO cell-derived rhBMP-2 in vitro and in small-animal models. The objective of this study is to evaluate the efficacy of E. coli-derived rhBMP-2 compared to the benchmark CHO cell-derived rhBMP-2 using an established large-animal model. Methods: Contralateral, critical-size supraalveolar peri-implant defects in six adult male Hound Labrador mongrel dogs received CHO cell- or E. coli-derived rhBMP-2 (0.2 mg/mL) in an absorbable collagen sponge (ACS) carrier. In each quadrant, three dental implants were placed. A titanium mesh device was used to support space provision. The animals received fluorescent bone markers for qualitative evaluations. Animals were euthanized at 8 weeks for histopathologic and histometric evaluation. Results: Clinical healing included significant swelling, but none of the animals experienced wound dehiscences. CHO cell- and E. coli-derived rhBMP-2 supported comparable bone formation (new bone area, 35.8 ± 3.6 versus 30.1 ± 2.2 mm²; bone density, 31.8% ± 1.6% versus 35.6% ± 2.5%; and osseointegration, 32.9% ± 7.4% versus 33.7% ± 8.1%) without statistically significant differences between treatments. Newly formed immature delicate trabecular bone in fibrovascular marrow filled the space underneath the titanium mesh and extended coronally above the mesh. Seroma formation was frequently observed. There were no discernable qualitative histologic differences between treatments. Conclusion: CHO cell- and E. coli-derived rhBMP-2 in an ACS carrier appear equally effective at inducing local bone formation in support of dental implant osseointegration. [ABSTRACT FROM AUTHOR]

In this paper, an electrocardiogram (ECG)-based pattern analysis methodology is presented for the detection of artrial flutter and atrial fibrillation using fractal dimension (FD) of continuous wavelet transform (CWT) coefficients of raw ECG signals, sample entropy of heart beat interval time series, and mean heart beat interval features. Accurate diagnosis of atrial tachyarrhythmias is important, as they have different therapeutic options and clinical decisions. In view of this, we have made an attempt to develop a discrimination mechanism between artrial flutter and atrial fibrillation. The methodology consists of mean heart beat interval detection using Pan Tompkins algorithm, calculation of sample entropy of heart beat interval time series, computation of box counting FD from CWT coefficients of raw ECG, statistical significance test, and subsequent pattern classification using different classifiers. Different wavelet basis functions like Daubechies-4, Daubechies-6, Symlet-2, Symlet-4, Symlet-6, Symlet-8, Coiflet-2, Coiflet-5, Biorthogonal-1.3, Biorthogonal-3.1, and Mayer wavelet have been used to compute CWT coefficients. Features are evaluated using statistical analysis and subsequently two-class pattern classification is done using unsupervised (k-means, fuzzy c-means, and Gaussian mixture model) and supervised (error back propagation neural network and support vector machine) techniques. In order to reduce the bias in choosing the training and testing set, k-fold cross validation is used. The obtained results are compared and discussed. It is found that the supervised classifiers provide higher accuracy in comparison to the set of unsupervised classifiers. [ABSTRACT FROM AUTHOR]

Dahl in 1975 gave a concept describing the management of tooth surface loss (TSL). Dahl's concept can be successfully and safely applied to a variety of clinical situations. This clinical report describes the treatment of a partially edentulous patient with generalized TSL. A simplified form of Dahl's appliance was used to create inter-occlusal space, to facilitate a cost-effective treatment and meet the functional and psychological needs of the patient. Thereby the treatment described has simplified the management of historically complex problem. [ABSTRACT FROM AUTHOR]

The effects of a layer-by-layer assembled carbon nanotube composite (CNT-comp) on osteoblasts in vitro and bone tissue in vivo in rats were studied. The effects of CNT-comp on osteoblasts were compared against the effects by commercially pure titanium (cpTi) and tissue culture dishes. Cell proliferation on the CNT-comp and cpTi were similar. However, cell differentiation, measured by alkaline phosphatase activity and matrix mineralization, was better on the CNT-comp. When implanted in critical-sized rat calvarial defect, the CNT-comp permitted bone formation and bone repair without signs of rejection or inflammation. These data indicate that CNT-comp may be a promising substrate for use as a bone implant or as a scaffold for tissue engineering. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2010. [ABSTRACT FROM AUTHOR]

A healthy 2-year-old girl bit a green chilli accidentally following which she had many bouts of vomiting. She became unconscious and was immediately admitted to hospital. In spite of all medical intervention, she died after one day. The autopsy confirmed that the death was caused by respiratory failure due to acute respiratory distress syndrome following aspiration of gastric contents into tracheobronchial tree. Aspiration of gastric contents resulting in acute respiratory distress syndrome and death is not uncommon; however, death following the accidental bite of a chilli is rarely reported in medical-legal literature. [ABSTRACT FROM AUTHOR]

Background: Sinus augmentation with simultaneous implant placement without bone graft material is a hotly debated technique. This technique could be improved and secured by the use of an autologous leukocyte- and platelet-rich fibrin (PRF) (Choukroun's technique) concentrate. The objectives of this study were to assess the relevance of PRF clots and membranes as the sole filling material during a lateral sinus lift with immediate implantation using radiologic and histologic analyses in a case series. Methods: Twenty-five sinus elevations with simultaneous implantation were performed on 20 patients with Choukroun's PRF as the sole filling biomaterial. For each patient, a presurgical exam and a 6-month postsurgical radiologic exam were performed with a panoramic x-ray and three-dimensional volumetric computed radiography (VCR) to evaluate the subsinus residual bone height and the final bone gain around the implants. In nine patients, 6 months after the sinus lift, bone biopsies were collected on the buccal wall of the alveolar ridge at the level of the osteotomy window, and evaluated by histomorphometry. Results: In this study, 41 implants from three different systems with different screw designs (Biomet 31 Nanotite, MIS Seven, Intra-Lock Ossean) were placed. All implants were inserted in residual bone height between 1.5 and 6 mm (mean ± SD: 2.9 ± 0.9 mm). The final bone gain was always very significant (between 7 and 13 mm [mean ± SD: 10.1 ± 0.9 mm]). No implant was lost. After radiologic analyses, the position of the final sinus floor was always in the continuation of the end of the implant. All biopsies showed well organized and vital bone. Conclusions: From a radiologic and histologic point of view at 6 months after surgery, the use of PRF as the sole filling material during a simultaneous sinus lift and implantation stabilized a high volume of natural regenerated bone in the subsinus cavity up to the tip of the implants. Choukroun's PRF is a simple and inexpensive biomaterial, and its systematic use during a sinus lift seems a relevant option, particularly for the protection of the Schneiderian membrane. [ABSTRACT FROM AUTHOR]

Purpose: To assess the histologic response of the periodontium, cementum, and pulp after intentional root injury with titanium screws. Materials and Methods: Three female beagle dogs were used, and a total of 60 self-drilling/self-tapping miniscrews were manually inserted into the maxilla and the mandible with the intention of placement in close proximity or in direct contact with the roots. Digital radiographs were taken to select the sites with root injuries. After a 3-month period, the animals were killed and serial nondecalcified histologic sections were obtained with the miniscrew in place. Results: Sixteen sites with significant root injury were identified. Four sites presented with cementum abrasion, 7 sites had dentin penetration up to 50% of the diameter of the screw, and 5 sites had miniscrew penetration into the pulp space with root fragmentation. At all damaged sites, continuous cementum repair could be observed. There was no evidence of external resorption or pulpal necrosis and/or inflammatory infiltrate. Point ankylosis was seen only in cases of severe injury with root fragmentation. Finally, woven bone was present along the miniscrew threads. Conclusion: When titanium screws penetrate root cementum or dentin, pulpal necrosis and/or inflammation was not observed at 12 weeks in an animal model. Cementum regenerates at every injury site, but ankylosis can occur with root fragmentation. Woven bone is present at the screw-bone interface even with root contact suggesting osteointegration. [Copyright &y& Elsevier]

PURPOSE: To determine the efficacy of an alloplastic graft material, consisting of a pure-phase β-tricalcium phosphate (β-TCP), in the preservation of ridge volume after tooth extraction and before dental implant placement. Histomorphometric analysis was completed on a few samples to determine the percentage of vital bone over a fixed healing period. MATERIALS AND METHODS: Patients requiring tooth extraction and bone regeneration before implant placement were included in this study. Measurements of alveolar width were made at the time of extraction and the time of implant placement. The extraction sites were grafted with a pure-phase β-TCP and covered with a barrier. Approximately 6 months after surgery, the sites were reentered for implant placement. Cores were taken of the regenerated material for histologic analysis, with a trephine used as the first bur in preparation for some of the osteotomies. Implants were placed according to the manufacturers' recommendations and loaded at the appropriate time. RESULTS: The β-TCP placed at the time of grafting extraction sockets was well tolerated in all sites with all of the barriers used. There were no incidences of postoperative infection or graft rejection. At the time of implant placement, much of the graft material had resorbed and been converted to vital alveolar bone. The implant recipient sites were dense and supported placement of endosseous dental implants that were fully stable. The width of the extraction sockets was preserved to 91% of the preoperative width. CONCLUSIONS: Extraction socket grafting with the pure-phase β-TCP tested in this study and covered with either a resorbable collagen or dense polytetrafluoroethylene barrier is a predictable method for preserving alveolar dimensions. The graft material resorbs to a high percentage in the timeframe desired between extraction and dental implant placement, as shown clinically, radiographically, and histologically. In addition, the regenerated material in the socket has enough density to support implant placement with subsequent loading in the 4- to 6-month period used in this study. [ABSTRACT FROM AUTHOR]

The article presents a study which investigated the occurrence of osteopenia as a result of enhanced osteoclastogenesis in twisted gastrulation(TWSG1)-deficient mice using increased bone morphogenetic proteins (BMP) signaling. It is stated that bone tissue deterioration resulted in increased bone fragility, bone pain and periodontal bone loss. The findings of primary osteoblast cultures and dynamic histomorphometric analysis are discussed.

The goal of this retrospective study was to evaluate the survival rates of dental implants placed in sinuses grafted with a 50:50 composite ratio of autogenous bone and a natural flourohydroxyapatite (FHA) combined with platelet-rich plasma (PRP) using an immediate-load protocol. The authors hypothesized that a 50:50 composite ratio of FHA and autogenous bone combined with PRP would permit immediate loading without compromising implant survival rates. Eleven patients with bilateral partial edentulism of the posterior maxilla were enrolled in this retrospective study. Autogenous bone used in the graft procedure was harvested from the tibia of the left lower extremity. Each patient was grafted with a 50:50 composite ratio of autogenous bone and FHA. Membranes were not used to cover the lateral wall osteotomy site. Platelet-rich plasma was added to the graft material to accelerate and enhance bone regeneration. Four to 6 months after the grafting procedure, 37 hydroxyapatite-coated dental implants were surgically placed and immediately loaded between 72 hours and 5 days later with custom titanium abutments and acrylic provisional restorations placed out of functional occlusion. Six months later, definitive ceramometal restorations were cemented on to the custom abutments. Patients were observed over a 52-week period. The overall implant survival rate was 97.3%. Histologic and histomorphometric analysis of core samples revealed formation of new vital bone in different graft specimens ranging from 23% to 34%. In each core bone sample, 100% of the bone sample was determined to be vital. In the grafted maxillary sinus, the natural FHA combined with autogenous bone in a 50:50 composite ratio with PRP is a suitable graft material permitting immediate load without compromising implant survival rates while decreasing the overall healing time. [ABSTRACT FROM AUTHOR]

Alveolar atrophy following tooth extraction remains a challenge for future dental implant placement. Immediate implant placement and postextraction alveolar preservation are 2 methods that are used to prevent significant postextraction bone loss. In this article, we report the management of a maxillary tooth extraction socket using an alveolar preservation technique involving placement of a cone of beta-tricalcium phosphate (β-TCP) combined with type I collagen without the use of barrier membranes or flap surgery. Clinical examination revealed solid new bone formation 9 months after the procedure. At the time of implant placement, histomorphometric analysis of the biopsied bone showed that it contained 62.6% mineralized bone, 21.1% bone marrow and 16.3% residual β-TCP graft. The healed bone was able to support subsequent dental implant placement and loading. [ABSTRACT FROM AUTHOR]

Copyright of Implant Dentistry is the property of Lippincott Williams & Wilkins and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Implant Dentistry is the property of Lippincott Williams & Wilkins and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Calcium sulfate (CS) is widely used as a bone graft binder and expander. Recent reports indicate that carboxymethylcellulose (CMC) can improve the clinical properties of CS when used as binder for particulate bone grafts; however, limited information is available on the effects of CMC on bone regeneration. The purpose of this study was to evaluate the histologic and morphometric characteristics of bone formation in calvarial defects grafted with a CS‐based putty containing 10% CMC in combination with allogeneic demineralized bone matrix (DBM). Bone formation and graft/binder resorption were compared with a surgical grade CS and DBM in paired critical‐sized calvarial defects in 25 Wistar rats (350–450 g). Six animals each provided paired defects at 7, 14, 21, and 28 days postsurgery for nondecalcified processing and microscopic analysis. Defects grafted with CS or CS‐CMC putty as the DBM binder exhibited similar patterns and proportions of bone formation, fibrous tissue/marrow, and residual DBM particles. Comparable mean ± SD proportions of new bone formation (31.7 ± 9.5 and 33.7 ± 12.9), fibrous tissue/marrow (54.2 ± 8.3 and 53.0 ± 10.8), residual DBM particles (8.3 ± 6.8 and 10.1 ± 6.3), and residual binder material (5.5 ± 4.6 and 3.7 ± 3.5) were found at 28 days for defects grafted with CS and CS‐CMC putty, respectively. Thus, CMC was found to improve the handling characteristics of CS and, when used in conjunction with DBM, supported comparable levels bone formation and patterns of binder/scaffold resorption as CS and DBM in a calvarial defect model. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007 [ABSTRACT FROM AUTHOR]

Efficacy of certain plant extracts in reducing Bean common mosaic potyvirus strain blackeye cowpea mosaic (BCMV-BlCM) disease in cowpea was evaluated. All the six botanicals Azadirachta indica, Boerhaavia diffusa, Bougainvillea spectabilis, Clerodendrum inerme, Psidium guajava, and Thuja occidentalis improved the germination and vigour index of cowpea. The disease incidence was reduced to 7% when 0.75% (w/v) of B. diffusa leaf extract was used as seed treatment under screen house conditions when compared to 80% in control. Under field conditions B. diffusa reduced the disease incidence up to 40% at 0.75% (w/v) concentration of extract. In spray treatment, B. diffusa and B. spectabilis reduced the disease incidence up to 13 and 12% under screenhouse conditions, whereas B. diffusa and C. inerme reduced the disease incidence up to 31 and 32% under field conditions. When plant extracts were mixed with BCMV-BlCM inoculum and young seedlings inoculated, B. spectabilis, C. inerme and M. jalapa extracts reduced the disease incidence up to 42, 40 and 48% respectively under screenhouse conditions when compared with the control. [ABSTRACT FROM AUTHOR]

Objective: Novel implant technologies and reconstructive therapies for alveolar augmentation require pre-clinical evaluation to estimate their biologic potential, efficacy, and safety before clinical application. The objective of this report is to present characteristics and use of the critical-size, supraalveolar, peri-implant defect model. Methods: Bilateral extraction of the mandibular premolars was performed in 12 Hound Labrador mongrel dogs following horizontal surgical cut-down of the alveolar ridge approximating 6 mm. Each jaw quadrant received three custom-produced TiUnite™, ∅4.0 × 10 mm threaded implants placed into osteotomies prepared into the extraction sites of the third and fourth premolars. The implants exhibited a reference notch 5 mm from the implant platform to facilitate surgical placement leaving 5 mm of the implant in a supraalveolar position, and to serve as a reference point in the radiographic, histologic and histometric analysis. The implants were submerged under the mucoperiosteal flaps for primary intention healing. Fluorescent bone markers were administered at weeks 3 and 4 post-surgery, and pre-euthanasia. The animals were euthanized following an 8-week healing interval when block biopsies were collected for analysis. Results: Healing was generally uneventful. The radiographic and histometric evaluations demonstrate the limited osteogenic potential of this defect model. Whereas lingual peri-implant sites exhibited a mean (±SE) bone gain of 0.4±0.1 mm, resorption of the buccal crestal plate resulted in a mean bone loss of 0.4±0.2 mm for an overall osteogenic potential following sham-surgery averaging 0.0±0.1 mm. Overall bone density and bone–implant contact in the contiguous resident bone averaged 79.1±1.1% and 76.9±2.3%, respectively. Conclusion: The results suggest that the critical-size, supraalveolar, peri-implant defect model appears a rigorous tool in the evaluation of candidate technologies for alveolar reconstruction and osseointegration of endosseous oral implants. Limited innate osteogenic potential allows critical evaluation of osteogenic, osteoconductive, or osteoinductive technologies in a challenging clinical setting. [ABSTRACT FROM AUTHOR]

Background: A synthetic peptide (P-15) analog of collagen added to anorganic bovine bone mineral (ABM) has recently been used as an enhanced bone graft material (ABM/P-15). The objective of this study was to test the contribution of ABM/P-15 in a new putty form (PEP) in two experimental membrane protected defects: periodontal and intrabony. Its efficacy as filler biomaterial in guided tissue regeneration (GTR) and guided bone regeneration (GBR) procedures was evaluated histologically and morphometrically. Methods: In the maxillary canines, a facial mucoperiosteal flap was raised bilaterally in nine dogs. Two circular defects, 5 mm in diameter and 2 mm in depth, were made on each side: a fenestrated periodontal on the canine root and an intrabony in the alveolar diastema, anteriorly. PEP particles filled both defects on one side; the contralateral side was blood filled (control). All surgical sites were covered with a bioabsorbable membrane. Histologically, at 4 months, tissue blocks were made using the cutting/grinding non-decalcification method followed by morphometric analysis. In the periodontal fenestration root surface, the linear percentage of new cementum (%CEM), area percentage of new bone (%NB), and residual biomaterial particles (%PEP) were calculated. These same measurements were calculated at the intrabony sites, except cementum. The amount of direct NB to PEP contact was measured to assess the osteoconductivity level (OSC). The Pearson correlation test was used to evaluate any significant relationship between the different measured parameters. Results: in the grafted and non-grafted fenestration root surface defects, %CEM averaged 59.5% and 73.93 (P <0.02), respectively; %NB averaged 36.1% and 31.4%, respectively; and %PEP averaged 20.6%. The mean percentage of OSC was 52.4%. In the intrabony grafted and non-grafted sites, %NB averaged 50.7% and 60.1%, respectively (P <0.02). Residual %PEP averaged 26.1%, and OSC averaged 35.6%. At the intrabony sites, higher %NB and lower %OSC were found compared to the fenestration sites (P<0,001 and P<0.03, respectively). Correlation analysis showed a negative correlation between %NB and %PEP at the fenestration defects. In between the two defect types, %OSC was significantly correlated (P<0.05). Conclusions: ABM/P-15 putty showed osteoconductive and biocompatible qualities. However, at 4 months in this model, no enhanced regeneration was present compared to a higher CEM and NB growth detected at non-grafted membrane-protected sites. [ABSTRACT FROM AUTHOR]

Copyright of Implant Dentistry is the property of Lippincott Williams & Wilkins and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Demineralized freeze-dried bone allografts (DFDBA) have been successfully used alone or in composite grafts for many decades. Little research has been done on the effect of retaining the mineral content of bone allografts. This study histologically and histomorphometrically evaluated a new mineralized bone allograft material placed in human atrophic maxillary sinuses. Seven partially edentulous patients requiring sinus grafts before implant placement were selected for this study. Their age range was 56 to 81 years {mean 67.7 years). Test grafts consisted of a mineralized solvent-dehydrated cancellous bone allograft, and control grafts were a composite of DFDBA and deproteinized bovine bone xenograft (1:1). Bilateral cases (n = 3) received both test and control grafts on opposite sides, and unilateral cases received either a test (n = 3) or control (n = 1) graft only. At 10 months, core biopsies were taken from each graft site, and dental implants were placed into the augmented bone. All bone grafts resulted in new bone formation and all implants osseointegrated. Test grafts resorbed and were replaced by newly formed bone significantly faster and in greater quantities than were control grafts. No complications with grafts or implants were noted. Both test and control grafts achieved excellent results. The faster bone formation observed with the test graft may be due, in part, to its smaller particle size compared with the bovine portion of the control graft. Test grafts were either replaced by new bone or displayed new bone-to-particle surface contact in higher percentages than did control grafts. No differences in osseointegration or graft stability were noted 2 years after the study. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to evaluate morphometrically the rate of resorbability of an inorganic bovine bone material in a standardized intrabony defect in dogs whether protected or unprotected by a bioabsorbable membrane at different healing periods, and to assess histomorphometrically the amount of osteoconductivity of this material and final healing site configuration. Methods: In eight mongrel dogs, four round intrabony defects (5 x 4 mm) were made on the lateral mandibular angle, bilaterally at a different given time. Bovine bone mineral randomly filled two sites, while the other two were left with blood clot. A bioabsorbable collagen membrane covered each type of defect. The blood clotted uncovered sites served as controls. Section blocks for histology were made at 3, 6, 12, and 24 months. Following the non-decalcification method and staining with Stevenel's blue and van Gieson's picro fuchsin, morphometric analysis was performed on each specimen lesion type. Results: Average bone area fraction at the bovine bone mineral uncovered sites (BBM) was 23.1%, 44%, 63.4%, and 58.8% at 3, 6, 12, and 24 months, respectively. Differences were statistically significant between 3 to 5 and 6 to 12 months (P <0.001). Average particle area fraction was 35.6%, 29%, 27.6%, and 26.8% at the respective periods. Differences were statistically significant between 3 to 6 months (P <0.05). In the bovine bone mineral membrane-protected (BBMM) sites, average bone area fraction was 26.4%, 51.7%, 61.2%, and 52.4% at 3, 5, 12, and 24 months, respectively. Differences were statistically significant between 3 to 6 months (P <0.05). Average particle area fraction was 37.9%, 29.8%, 26.3%, and 33.7%, respectively. Differences between the two sites with regard to the newly formed bone and particle presence were insignificant. In both, the increasing pattern of osteoconduction as expressed by the osteoconductivity test along the different healing periods was similar, as well as the decreasing pattern of the remaining concavity of the healing site configuration. Multiple comparison analysis of bone area fraction disclosed statistically significant superiority (P <0.05) of the membrane-ungrafted sites over BBM sites at 3 and 6 months and over BBMM sites at 6 months. Bone area fraction of the BBMM sites (51.7%) was statistically higher than the control sites (37.5%) (P <0.05). At 12 months, all test sites were statistically superior over the controls with regard to the regenerated bone and its healing configuration; i.e., remaining concavity of the defect. The healing site configuration of the test sites was persistently different from the control sites at 24 months. Conclusions: Newly formed bone and complete healing were evident in the BBM and BBMM sites. The membrane contributed no substantial benefits. Bovine bone particle resorptive phase was observed up to 6 months. Thereafter, there was no continued resorption up to 24 months observation. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to evaluate histologically the contribution of inorganic bovine bone biomaterial in a new experimental bone defect in dogs at different healing periods and to examine newly formed bone around the grafted mineral particles and their relationship in membrane-protected (test) and non-protected intrabony (control) defects. Methods: Four round intrabony defects, 5 x 4 mm were made bilaterally (at different times) on the lateral bony mandibular angle in eight dogs. Two defects were filled with bovine bone mineral (BBM) particles and two remained non-grafted but were blood clotted. A collagen membrane covered each defect type (n = 4). This procedure was repeated on the contralateral side at a different given time to obtain two different healing periods in each dog. Thus, four specimens were obtained at 3, 6, 12, and 24 months post-operatively for each healing period. The non-decalcification method (Donath technique) with Stevenel's blue and van Gieson's picro fuchsin staining was used for histological examination. Results: Newly formed bone was observed at all examined defect types. The BBM particles were clearly evident regardless of the healing period. At 3 and 6 months, newly formed bone, woven in nature, was incorporated with the grafted particles. High cellular bone with occasional osteoclasts was noted towards the surface of the mineral particles. No substantial difference was observed between the protected and the non-protected defects except for higher ossified centers around the membrane-protected defects. At the non-grafted sites, the membrane-protected defect showed newly formed bone near the bony walls, and particularly under the membrane, establishing a bony bridge over the defect at the healing periods. The non-grafted unprotected defect (control) showed bone formation only at the base and close to the bony walls leaving a healed concave configuration. At 1 and 2 years, the grafted sites showed full bone healing configuration. However, the grafted particles still dominated the previous defect area and were completely surrounded by the newly formed bone. Osteons and lamellar bone arrangement were established but the bone was still highly cellular and osteoclasts could still be identified. The non-grafted membrane-protected sites showed excellent bone healing although areas of non-mineralized soft tissue were often seen. The control sites healed but still presented with a concave surface configuration. Conclusions: BBM biomaterial is a highly osteoconductive material. In a 4-wall bony defect, newly formed bone was well evident in establishing excellent bone healing configuration with or without a regenerative biological barrier. The grafted material dominated the experimental sites with no substantial resorption at any healing period up to 2 years observation. [ABSTRACT FROM AUTHOR]