Enhanced bone tissue regeneration with hydrogel-based scaffolds by embedding parathyroid hormone in mesoporous bioactive glass.

OBJECTIVES: To evaluate hydrogel-based scaffolds embedded with parathyroid hormone (PTH)-loaded mesoporous bioactive glass (MBG) on the enhancement of bone tissue regeneration in vitro. MATERIALS AND METHODS: MBG was produced via sol-gel technique followed by PTH solution imbibition. PTH-loaded MBG was blended into the hydrogels and submitted to a lyophilisation process associated with a chemical crosslinking reaction to the production of the scaffolds. Characterisation of the MBG and PTH-loaded MBG scaffolds, including the scanning electron microscope (SEM) connected with an X-ray detector (EDX), Fourier transform infrared (FTIR), compression strength, rheological measurements, swelling and degradation rates, and PTH release analysis, were performed. Also, bioactivity using simulated-body fluid (SBF), biocompatibility (MTT), and osteogenic differentiation analyses (von Kossa and Alizarin Red stainings, and µ-computed tomography, µCT) of the scaffolds were carried out. RESULTS: SEM images demonstrated MBG particles dispersed into the hydrogel-based scaffold structure, which was homogeneously porous and well interconnected. EDX and FTIR revealed large amounts of carbon, oxygen, sodium, and silica in the scaffold composition. Bioactivity experiments revealed changes on sample surfaces over the analysed period, indicating the formation of carbonated hydroxyapatite; however, the chemical composition remained stable. PTH-loaded hydrogel-based scaffolds were biocompatible for stem cells from human-exfoliated deciduous teeth (SHED). A high quantity of calcium deposits on the extracellular matrix of SHED was found for PTH-loaded hydrogel-based scaffolds. µCT images showed MBG particles dispersed into the scaffolds' structure, and a porous, lamellar, and interconnected hydrogel architecture. CONCLUSIONS: PTH-loaded hydrogel-based scaffolds demonstrated consistent morphology and physicochemical properties for bone tissue regeneration, as well as bioactivity, biocompatibility, and osteoinductivity in vitro. Thus, the scaffolds presented here are recommended for future studies on 3D printing. CLINICAL RELEVANCE: Bone tissue regeneration is still a challenge for several approaches to oral and maxillofacial surgeries, though tissue engineering applying SHED, scaffolds, and osteoinductive mediators might help to overcome this clinical issue.

Dimensional Influence of Epithelialized Tissue Graft Harvested From Palate on Postoperative Pain: a Systematic Review.

Objectives: The aim of the present systematic review was to evaluate the dimensional influence of the epithelialized tissue graft harvested from the palate in the postoperative pain. Material and Methods: Research was conducted in electronic databases Cochrane Library, Embase, LILACS, PubMed, Scopus, and Web of Science upwards May 15, 2022. Studies that reported the influence of graft dimensions of palatal epithelized harvesting on postoperative pain were eligible. The evaluation was made using the methodological quality assessment by Joanna Briggs Institute Critical Appraisal Checklist for randomized clinical trials and non-randomized studies and the level of evidence according to GRADE. Results: Four studies were included. The clinical and methodological heterogeneity among studies led to an analysed narrative. The postoperative pain was assessed during the period of 1 to 28 postoperative days. It was determined by using visual analog scale in three studies, while the evaluation was performed indirectly based on analgesics intake in one study. According to three studies, bigger graft sizes were associated with higher postoperative pain. The methodological quality assessment categorized two study as high (one randomized control trial and one non-randomized), and two as moderate (one randomized control trial and one non-randomized). The data was considered moderate. Conclusions: Based on the moderate certainty level, bigger graft sizes of palatal epithelized harvesting appear to promote more postoperative pain. Understanding the postoperative pain as a response to a graft extension may assist some clinical decisions regarding the surgical periodontal and peri-implant planning.

Virucidal activity of microalgae extracts harvested during phycoremediation of swine wastewater.

Phycoremediation of swine wastewater is a promising treatment since it efficiently removes nutrients and contaminants and, simultaneously, its biomass can be harvested and used to obtain a wide range of valuable compounds and metabolites. In this context, biomass microalgae were investigated for the phycoremediation of swine wastewater, and biomass extracts for its virucidal effect against enveloped and non-enveloped viruses. Microalgae were cultivated in a pilot scale bioreactor fed with swine wastewater as the growth substrate. Hexane, dichloromethane, and methanol were used to obtain the microalgae extracts. Extracts were tested for virucidal potential against HSV-1 and HAdV-5. Virucidal assays were conducted at temperatures that emulate environmental conditions (21 °C) and body temperature (37 °C). The maximum production of microalgae biomass reached a concentration of 318.5 ± 23.6 mgDW L-1. The results showed that phycoremediation removed 100% of ammonia-N and phosphate-P, with rates (k1) of 0.218 ± 0.013 and 0.501 ± 0.038 (day-1), respectively. All microalgae extract reduced 100% of the infectious capacity of HSV-1. The microalgae extracts with dichloromethane and methanol showed inhibition activities at the lowest concentration (3.125 µg mL-1). Virucidal assays against HAdV-5 using microalgae extract of hexane and methanol inhibited the infectious capacity of the virus by 70% at all concentrations tested at 37 °C. At a concentration of 12.5 µg mL-1, the dichloromethane microalgae extract reduced 50-80% of the infectious capacity of HAdV-5, also at 37 °C. Overall, the results suggest that the microalgae can be an attractive source of feedstock biomass for the exploration of alternative virucidal compounds.

Diagnostic performance of periapical and panoramic radiography and cone beam computed tomography for detection of circumferential gaps simulating osseointegration failure around dental implants: A systematic review.

OBJECTIVE: The objective of this study was to appraise the diagnostic performance of periapical (PR) and panoramic (PANO) radiographs and cone beam computed tomography (CBCT) in detecting artificial circumferential gaps simulating osseointegration failure around dental implants in ex vivo studies. STUDY DESIGN: Seven electronic databases and three gray literature sources were searched. Studies reporting diagnostic performance measures or data allowing calculation of those measures compared with the reference standard of in situ direct measurements were considered eligible. Either the area under the receiver operating characteristic curve or accuracy was chosen to summarize findings, with diagnostic performance interpreted as poor, acceptable, excellent, or outstanding. Risk of bias (RoB) was also assessed. RESULTS: The ten included studies mostly suggested overall excellent to outstanding diagnostic capability with PR and CBCT. Various enhancement filters, CBCT voxel sizes, and/or fields of view were associated with acceptable to outstanding efficacy. PANO had the poorest results, with most research demonstrating acceptable to excellent discrimination. The RoB was high for seven studies, moderate for two, and low for -one. CONCLUSIONS: PR and CBCT images were generally superior to PANO for the detection of artificial bone gaps. Results should be interpreted with caution because most studies had a high RoB.

Bioactive Compounds from Mangrove Endophytic Fungus and Their Uses for Microorganism Control.

Mangroves are ecosystems with unique characteristics due to the high salinity and amount of organic matter that house a rich biodiversity. Fungi have aroused much interest as they are an important natural source for the discovery of new bioactive compounds, with potential biotechnological and pharmacological interest. This review aims to highlight endophytic fungi isolated from mangrove plant species and the isolated bioactive compounds and their bioactivity against protozoa, bacteria and pathogenic viruses. Knowledge about this type of ecosystem is of great relevance for its preservation and as a source of new molecules for the control of pathogens that may be of importance for human, animal and environmental health.

Effect of cyanoacrylate tissue adhesive in postoperative palatal pain management: a systematic review.

OBJECTIVE: To critically appraise available literature concerning the effect of cyanoacrylate tissue adhesive (CTA) in postoperative palatal pain management. MATERIALS AND METHODS: Electronic databases (Cochrane, PubMed, LILACS, Scopus, and Web of Science) were searched, complemented with grey literature databases up to June 2020. Studies reporting the effect of cyanoacrylate tissue adhesive compared to any other methods in postoperative palatal pain management were considered eligible. The risk of bias among and across included studies was assessed. RESULTS: Finally, four studies were considered eligible. Regarding free gingival graft (FGG), cyanoacrylate tissue adhesive with hemostatic sponge promoted less postoperative pain (PP) and analgesic consumption (AC). Also, cyanoacrylate tissue adhesive with platelet-rich fibrin produced less PP and more wound healing at the palatal area than cyanoacrylate tissue adhesive and wet gauze. Additionally, cyanoacrylate tissue adhesive promoted less PP and AC than wet gauze and suture. Concerning connective tissue graft (CTG), cyanoacrylate tissue adhesive, and suture produced similar PP, AC, and willingness for retreatment. CONCLUSIONS: Based on the low certainty level, cyanoacrylate tissue adhesive appears to promote less PP and AC than wet gauze and suture regarding FGG. Additionally, cyanoacrylate tissue adhesive appears to increase the effect of hemostatic sponge, contributing to the reduction of PP and AC. Regarding CTG, cyanoacrylate tissue adhesive appears to promote similar PP, AC, and willingness for retreatment than the suture. Therefore, cyanoacrylate tissue adhesive has shown promising usefulness for PP management in FGG, but not a clear benefit for CTG. CLINICAL RELEVANCE: The adoption of different agents for the protection of the palatal donor site following gingival harvesting procedures may provide better comfort to the patient.

PLGA+HA/ßTCP Scaffold Incorporating Simvastatin: A Promising Biomaterial for Bone Tissue Engineering.

The aim of this study was to synthesize, characterize, and evaluate degradation and biocompatibility of poly(lactic-co-glycolic acid) + hydroxyapatite/ß-tricalcium phosphate (PLGA+HA/ßTCP) scaffolds incorporating simvastatin (SIM) to verify if this biomaterial might be promising for bone tissue engineering. Samples were obtained by the solvent evaporation technique. Biphasic ceramic particles (70% HA, 30% ßTCP) were added to PLGA in a ratio of 1:1. Samples with SIM received 1% (m/m) of this medication. Scaffolds were synthesized in a cylindric shape and sterilized by ethylene oxide. For degradation analysis, samples were immersed in phosphate-buffered saline at 37°C under constant stirring for 7, 14, 21, and 28 days. Nondegraded samples were taken as reference. Mass variation, scanning electron microscopy, porosity analysis, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetry were performed to evaluate physico-chemical properties. Wettability and cytotoxicity tests were conducted to evaluate the biocompatibility. Microscopic images revealed the presence of macro-, meso-, and micropores in the polymer structure with HA/ßTCP particles homogeneously dispersed. Chemical and thermal analyses presented similar results for both PLGA+HA/ßTCP and PLGA+HA/ßTCP+SIM. The incorporation of simvastatin improved the hydrophilicity of scaffolds. Additionally, PLGA+HA/ßTCP and PLGA+HA/ßTCP+SIM scaffolds were biocompatible for osteoblasts and mesenchymal stem cells. In summary, PLGA+HA/ßTCP scaffolds incorporating simvastatin presented adequate structural, chemical, thermal, and biological properties for bone tissue engineering.

Number of dental abutments influencing the biomechanical behavior of tooth‒implant-supported fixed partial dentures: A finite element analysis.

Background. Local or systemic issues might prevent installing a sufficient number of dental implants for fixed prosthetic rehabilitation. Splinting dental implants and natural teeth in fixed dentures could overcome such limitations. Therefore, this study aimed to evaluate the influence of the number of dental abutments in the biomechanics of tooth‒implant-supported fixed partial dentures (FPDs). The null hypothesis was that increasing the number of abutment teeth would not decrease the stress over the abutments and surrounding bone. Methods. Left mandibular lateral incisor, canine, premolars, and molars were reconstructed through computed tomography and edited using image processing software to represent a cemented fixed metal‒ceramic partial denture. Three models were set to reduce the number of abutment teeth: 1) lateral incisor, canine, and first premolar; 2) canine and first premolar; 3) the first premolar. The second premolar and first molar were set as pontics, and the second molar was set as an implant abutment in all the models. Finite element analyses were performed under physiologic masticatory forces with axial and oblique loading vectors. Results. After simulation of axial loads, the stress peaks on the bone around the implant, the bone around the first premolar, and prosthetic structures did not exhibit significant changes when the number of abutment teeth decreased. However, under oblique loads, decreasing the number of abutment teeth increased stress peaks on the surrounding bone and denture. Conclusion. Increasing the number of dental abutments in tooth‒implant-supported cemented FPD models decreased stresses on its constituents, favoring the prosthetic biomechanics.

Retinoic acid increases the effect of bone morphogenetic protein type 2 on osteogenic differentiation of human adipose-derived stem cells.

BACKGROUND: Bone morphogenetic protein type 2 (BMP-2) and retinoic acid (RA) are osteoinductive factors that stimulate endogenous mechanisms of bone repair which can be applied on management of osseous defects in oral and maxillofacial fields. OBJECTIVE: Considering the different results of RA on osteogenesis and its possible use to substitute/potency BMP-2 effects, this study evaluated the outcomes of BMP-2, RA, and BMP-2+RA treatments on in vitro osteogenic differentiation of human adipose-derived stem cells (ASCs) and the signaling pathway(s) involved. MATERIAL AND METHODS: ASCs were treated every other day with basic osteogenic medium (OM) alone or supplemented with BMP-2, RA, or BMP-2+RA. Alkaline phosphatase (ALP) activity was determined using the r-nitrophenol method. Extracellular matrix mineralization was evaluated using von Kossa staining and calcium quantification. Expression of osteonectin and osteocalcin mRNA were determined using qPCR. Smad1, Smad4, phosphorylated Smad1/5/8, BMP-4, and BMP-7 proteins expressions were analyzed using western blotting. Signaling pathway was evaluated using the IPA® software. RESULTS: RA promoted the highest ALP activity at days 7, 14, 21, and 28, in comparison to BMP-2 and BMP-2+RA. BMP-2+RA best stimulated phosphorylated Smad1/5/8 protein expression at day 7 and Smad4 expression at days 7, 14, 21, and 28. Osteocalcin and osteonectin mRNA expressions were best stimulated by BMP-2+RA at day 7. Matrix mineralization was most improved by BMP-2+RA at days 12 and 32. Additionally, BMP-2+RA promoted the highest BMP signaling pathway activation at days 7 and 14, and demonstrated more activation of differentiation of bone-forming cells than OM alone. CONCLUSIONS: In summary, RA increased the effect of BMP-2 on osteogenic differentiation of human ASCs.

Retinoic acid increases the effect of bone morphogenetic protein type 2 on osteogenic differentiation of human adipose-derived stem cells

Abstract Bone morphogenetic protein type 2 (BMP-2) and retinoic acid (RA) are osteoinductive factors that stimulate endogenous mechanisms of bone repair which can be applied on management of osseous defects in oral and maxillofacial fields. Objective Considering the different results of RA on osteogenesis and its possible use to substitute/potency BMP-2 effects, this study evaluated the outcomes of BMP-2, RA, and BMP-2+RA treatments on in vitro osteogenic differentiation of human adipose-derived stem cells (ASCs) and the signaling pathway(s) involved. Material and Methods ASCs were treated every other day with basic osteogenic medium (OM) alone or supplemented with BMP-2, RA, or BMP-2+RA. Alkaline phosphatase (ALP) activity was determined using the r-nitrophenol method. Extracellular matrix mineralization was evaluated using von Kossa staining and calcium quantification. Expression of osteonectin and osteocalcin mRNA were determined using qPCR. Smad1, Smad4, phosphorylated Smad1/5/8, BMP-4, and BMP-7 proteins expressions were analyzed using western blotting. Signaling pathway was evaluated using the IPA® software. Results RA promoted the highest ALP activity at days 7, 14, 21, and 28, in comparison to BMP-2 and BMP-2+RA. BMP-2+RA best stimulated phosphorylated Smad1/5/8 protein expression at day 7 and Smad4 expression at days 7, 14, 21, and 28. Osteocalcin and osteonectin mRNA expressions were best stimulated by BMP-2+RA at day 7. Matrix mineralization was most improved by BMP-2+RA at days 12 and 32. Additionally, BMP-2+RA promoted the highest BMP signaling pathway activation at days 7 and 14, and demonstrated more activation of differentiation of bone-forming cells than OM alone. Conclusions In summary, RA increased the effect of BMP-2 on osteogenic differentiation of human ASCs.

Adipose-Derived Stem Cells Decrease Bone Morphogenetic Protein Type 2-Induced Inflammation In Vivo.

PURPOSE: Recombinant human bone morphogenetic protein type 2 (rhBMP-2) has been used to promote bone regeneration. In contrast, some reports have suggested rhBMP-2 does not provide advantages over autogenous bone grafting owing to the undesirable postoperative symptoms of this growth factor. Because the undesirable symptoms of rhBMP-2 are usually promoted by inflammation, this study evaluated the in vivo effect of human adipose-derived stem cells (ASCs) incorporated into polylactic co-glycolic acid (PLGA) scaffolds in decreasing the inflammatory response induced by a low dose of rhBMP-2. MATERIALS AND METHODS: PLGA scaffolds were characterized and loaded with rhBMP-2 1, 2.5, or 5 µg per scaffold (n = 6) and the in vitro released protein amounts were quantified at 7 hours and 1, 7, and 21 days after loading (n = 3). The muscle tissue of 6 beagles received the following treatments: PLGA, PLGA plus rhBMP-2 (2.5 µg), and PLGA plus rhBMP-2 plus ASCs (1 × 10(6) ASCs). The samples were evaluated 45 days after surgery. Statistical analyses were performed and the P value was set at .05. RESULTS: PLGA plus rhBMP-2 plus ASCs yielded the smallest number of inflammatory foci (P < .001) and giant cells (P < .001) and the largest number of angiogenesis sites (P < .001). CONCLUSIONS: Human ASCs administered in vivo into PLGA scaffolds with a low dose of rhBMP-2 decrease tissue inflammation and increase angiogenesis in muscular sites.

Adipose-derived stem cells incorporated into platelet-rich plasma improved bone regeneration and maturation in vivo.

BACKGROUND/AIM: Some cases of tooth loss related to dental trauma require bone-grafting procedures to improve the aesthetics before prosthetic rehabilitation or to enable the installation of dental implants. Bone regeneration is often a challenge and could be largely improved by mesenchymal stem cells therapy. However, the appropriate scaffold for these cells still a problem. This study evaluated the in vivo effect of human adipose-derived stem cells incorporated into autogenous platelet-rich plasma in bone regeneration and maturation. MATERIAL AND METHODS: Adipose-derived stem cells were isolated from lipoaspirate tissues and used at passage 4. Immunophenotyping and multilineage differentiation of cells were performed and mesenchymal stem cells characteristics confirmed. Bicortical bone defects (10 mm diameter) were created in the tibia of six beagle dogs to evaluate the effect of adipose-derived stem cells incorporated into platelet-rich plasma scaffolds, platelet-rich plasma alone, autogenous bone grafts, and clot. Samples were removed 6 weeks postsurgeries and analyzed by quantification of primary and secondary bone formation and granulation tissue. RESULTS: Adipose-derived stem cells incorporated into platelet-rich plasma scaffolds promoted the highest bone formation (primary + secondary bone) (P < 0.001), the highest bone maturation (secondary bone) (P < 0.001), and the lowest amount of granulation tissue (P < 0.001). CONCLUSIONS: Adipose-derived stem cells incorporated into platelet-rich plasma scaffolds promote more bone formation and maturation, and less granulation tissue in bone defects created in canine tibia. Therefore, platelet-rich plasma can be considered as a candidate scaffold for adipose-derived stem cells to promote bone regeneration.

Development and physicochemical characterization of saquinavir mesylate solid dispersions using Gelucire 44/14 or PEG 4000 as carrier.

Solid dispersions of saquinavir mesylate containing either Gelucire® 44/14 or poly(ethylene glycol) (PEG) 4000, or mixtures of each carrier with Tween 80 or polyvinyl pyrrolidone (PVP) K30 were prepared in order to enhance the drug dissolution rate. These systems were prepared by the melting method and characterized by X-ray powder diffraction, microscopical techniques, and Raman spectroscopy aiming to establish a relationship between physicochemical and dissolution properties under different cooling conditions. Modifications in degree of crystalline order/disorder over time were observed in preparations with both carriers. Overall, formulations cooled and stored at -20 °C showed less variation in dissolution rates than those at 25 °C. Although Tween 80 has enhanced the known self-emulsifying properties of Gelucire® 44/14, its combination with PEG 4000 displayed miscibility problems. The addition of PVP K30 was not the most effective approach in enhancing the dissolution in early steps; however, the drug dissolution was stable after 7 days of storage at 25 °C. The combination of PEG 4000 and PVP K30 maintained the dissolution properties for 60 and 90 days at 25 °C/95% relative humidity and 40 °C/75% (f2 values >50), respectively.

Addition of bone morphogenetic protein type 2 to ascorbate and β-glycerophosphate supplementation did not enhance osteogenic differentiation of human adipose-derived stem cells

Bone morphogenetic protein type 2 (BMP-2) is a potent local factor, which promotes bone formation and has been used as an osteogenic supplement for mesenchymal stem cells. OBJECTIVES: This study evaluated the effect of a recombinant BMP-2 as well as the endogenous BMP-4 and BMP-7 in the osteogenic differentiation of adipose-derived stem cells (ASCs) in medium supplemented with ascorbate and β-glycerophosphate. MATERIAL AND METHODS: Human ASCs were treated with osteogenic medium in the presence (ASCs+OM+BMP-2) or absence (ASCs+OM) of BMP-2. The alkaline phosphatase (ALP) activity was determined and the extracellular matrix mineralization was evaluated by Von Kossa staining and calcium quantification. The expressions of BMP-4, BMP-7, Smad1, Smad4, and phosphorylated Smad1/5/8 were analyzed by western blotting. Relative mRNA expressions of Smad1, BMP receptor type II (BMPR-II), osteonectin, and osteocalcin were evaluated by qPCR. Results: ASCs+OM demonstrated the highest expression of BMP-4 and BMP-7 at days 21 and 7, respectively, the highest levels of BMPR-II mRNA expression at day 28, and the highest levels of Smad1 mRNA at days 14 and 28. ASCs+OM+BMP-2 demonstrated the highest levels of Smad1 mRNA expression at days 1, 7, and 21, the highest expression of Smad1 at day 7, the highest expression of Smad4 at day 14, the highest ALP activity at days 14 and 21, and expression of phosphorylated Smad1/5/8 at day 7. ASCs+OM and ASCs+OM+BMP2 showed similar ALP activity at days 7 and 28, similar osteonectin and osteocalcin mRNA expression at all time periods, and similar calcium depositions at all time periods. CONCLUSIONS: We concluded that human ASCs expressed endogenous BMP-4 and BMP-7. Moreover, the supplementation of ASCs with BMP-2 did not increase the level of osteogenic markers in the initial (ALP activity), intermediate (osteonectin and osteocalcin), or final (calcium deposition) phases, suggesting that the exogenous addition of BMP-2 did not improve the in vitro osteogenesis process of human ASCs.

Addition of bone morphogenetic protein type 2 to ascorbate and ß-glycerophosphate supplementation did not enhance osteogenic differentiation of human adipose-derived stem cells.

UNLABELLED: Bone morphogenetic protein type 2 (BMP-2) is a potent local factor, which promotes bone formation and has been used as an osteogenic supplement for mesenchymal stem cells. OBJECTIVES: This study evaluated the effect of a recombinant BMP-2 as well as the endogenous BMP-4 and BMP-7 in the osteogenic differentiation of adipose-derived stem cells (ASCs) in medium supplemented with ascorbate and ß-glycerophosphate. MATERIAL AND METHODS: Human ASCs were treated with osteogenic medium in the presence (ASCs+OM+BMP-2) or absence (ASCs+OM) of BMP-2. The alkaline phosphatase (ALP) activity was determined and the extracellular matrix mineralization was evaluated by Von Kossa staining and calcium quantification. The expressions of BMP-4, BMP-7, Smad1, Smad4, and phosphorylated Smad1/5/8 were analyzed by western blotting. Relative mRNA expressions of Smad1, BMP receptor type II (BMPR-II), osteonectin, and osteocalcin were evaluated by qPCR. RESULTS: ASCs+OM demonstrated the highest expression of BMP-4 and BMP-7 at days 21 and 7, respectively, the highest levels of BMPR-II mRNA expression at day 28, and the highest levels of Smad1 mRNA at days 14 and 28. ASCs+OM+BMP-2 demonstrated the highest levels of Smad1 mRNA expression at days 1, 7, and 21, the highest expression of Smad1 at day 7, the highest expression of Smad4 at day 14, the highest ALP activity at days 14 and 21, and expression of phosphorylated Smad1/5/8 at day 7. ASCs+OM and ASCs+OM+BMP2 showed similar ALP activity at days 7 and 28, similar osteonectin and osteocalcin mRNA expression at all time periods, and similar calcium depositions at all time periods. CONCLUSIONS: We concluded that human ASCs expressed endogenous BMP-4 and BMP-7. Moreover, the supplementation of ASCs with BMP-2 did not increase the level of osteogenic markers in the initial (ALP activity), intermediate (osteonectin and osteocalcin), or final (calcium deposition) phases, suggesting that the exogenous addition of BMP-2 did not improve the in vitro osteogenesis process of human ASCs.

Evaluation of the stress distribution in CFR-PEEK dental implants by the three-dimensional finite element method.

CFR-PEEK (carbon fiber reforced-poly ether ether ketone) has been demonstrated to be excellent substitute titanium in orthopedic applications and can be manufactured with many physical, mechanical, and surface properties, in several shapes. The aim of this study was to compare, using the three-dimensional finite element method, the stress distribution in the peri-implant support bone of distinct models composed of PEEK components and implants reinforced with 30% carbon fiber (30% CFR-PEEK) or titanium. In simulations with a perfect bonding between the bone and the implant, the 30% CFR-PEEK presented higher stress concentration in the implant neck and the adjacent bone, due to the decreased stiffness and higher deformation in relation to the titanium. However, 30% CFR-PEEK implants and components did not exhibit any advantages in relation to the stress distribution compared to the titanium implants and components.

Evaluation of physical-chemical properties and biocompatibility of a microrough and smooth bioactive glass particles.

The purpose of this study was to evaluate physical-chemical and biocompatibility characteristics of a simple synthesis and low cost experimental bioactive glass. Physical and chemical properties were analyzed using scanning electron microscopy (SEM), X-ray energy dispersive (EDX), X-ray fluorescence (XRF) and X-ray diffraction (XRD). The biomaterials were subcutaneously implanted into rats, according to the following groups: G1, PerioGlastrade mark; G2, Biograntrade mark, G3, Experimental Bioactive Glass U (BGU) and G4, Control (Sham). After 7, 15, 21, 45, and 60 days, 5 animals/group/period were sacrificed and the subcutaneous tissue was dissected for histological and histometric analysis, considering inflammatory reaction and granulation area, presence of polymorphonuclear (PMN), monuclear (MN) and fibroblast (F) cells. SEM analysis of biomaterials showed irregular particles with different surface characteristics. EDX showed calcium, oxygen, sodium, phosphorus and silicon; XRF revealed silica oxide (SiO(2)), sodium oxide (Na(2)O), calcium oxide (CaO) and phosphorus oxide (P(2)O(5)). XRD indicated non crystalline phase. Measurement of tissue reaction showed similar results among the experimental groups at 45 and 60 days. No difference was found for PMN, MN and F cell counts. All biomaterials exhibited partial resorption. In conclusion, the experimental bioactive glass analyzed showed physical and chemical characteristics similar to the commercially available biomaterials, and was considered biocompatible, being partially reabsorbed in the subcutaneous tissue.

Utilização de vidros bioativos como substitutos ósseos: revisão de literatura / Use of bioactive glasses as bone graft substitutes: a review of literature

Procedimentos de enxerto ósseo são utilizados com freqüência em cirurgias bucais e maxilofaciais. Em decorrência desse fato, a busca de um material ideal como substituto ósseo vem sendo objeto de pesquisa por anos. Como uma alternativa para o enxerto ósseo autógeno e alógeno vem se tentando empregar uma quantidade significativa de materiais, incluindo metais, cerâmicas e polímeros. A aplicabilidade desses materiais em organismos humanos depende de suas propriedades biológicas, químicas, físicas e mecânicas. Dentre os materiais cerâmicos utilizados como substitutos ósseos, os vidros bioativos representam materiais promissores por apresentarem boa biocompatibilidade, promoverem união química ao osso natural e apresentarem propriedades osteocondutivas. O objetivo deste trabalho é fazer uma revisão de literatura sobre a biocompatibilidade e propriedades físico-químicas de biovidros empregados como substitutos ósseos.

Bone graft procedures have been used commonly in buco-maxillo-facial surgery. For this reason, many research have been conduced to find the appropriate bone substitute. As an alternative for the autogenous and alogenous bone graft, we have trying to use significant kinds of materials, including metals, ceramic and polymeric. The applicability of these materials in human organisms depends on their biological properties, chemistries, physics and mechanics. Among the ceramic materials used as bone substitutes, the bioactive glasses have222 showed good properties with the biocompatibility, able to promote chemical union to the natural bone and have osteoconductive properties. The objective of this work is to do a literature review on the biocompatibility and physiochemical properties of bioactive glasses used as bone substitutes.

Avaliação radiográfica do contato proximal de restaurações em resina composta de Classe II / Radiographic evaluation of proximal contact of classe II composite resin restauration

Este trabalho teve por objetivo avaliar através de radiografias interproximais os contatos proximais de restaurações de classe II em resina composta. Os dados foram agrupados de acordo com os dentes (molares e pré-molares) e com a face (mesial e distal). A análise estatística foi feita por meio da diferença de proporções pelo Teste de Qui-quadrado (correção de Yates). Os resultados mostraram que 65,51% das restaurações apresentavam contato proximal adequado, enquanto 34,49% apresentavam contatos proximais inadequados. Comparando-se os molares com os pré-molares, 39 (44,82%) restaurações em molares apresentavam contato proximal satisfatório e 22 (25,28%) insatisfatório. Em relação aos pré-molares, 18 (20,68%) restaurações estavam satisfatórias, enquanto 8 (9,19%) insatisfatórias. Não havendo diferença estatisticamente significante entre a qualidade de contato proximal confeccionado nos molares e nos pré-molares (p=0,779). No que diz respeito às faces, 35 (40,23%) restaurações apresentavam contato proximal adequado na face mesial, enquanto 10 (11,51%) apresentavam contatos proximais inadequados. Tratando-se da distal, 22 (25,28%) restaurações estavam satisfatórias e 20 (22,98%) insatisfatórias. Sendo os contatos proximais confeccionados na face mesial de qualidade estatisticamente superior aos da face distal (p=0,0140). De acordo com a metodologia, conclui-se que os contatos proximais confeccionados nos dentes molares são de qualidade equivalente aos pré-molares e que os contatos proximais confeccionados na face mesial são de qualidade superior aos de face distal

Avaliação "in vitro" da influência de três sistemas fotopolimerizadores na formação de fendas cervicais / In vitro evaluation of three curing light systems on cervical gaps formation

O objetivo do estudo foi avaliar, in vitro, a influência de três sistemas fotopolimerizadores, existentes no mercado na formação de fendas cervicais em restaurações de classe V com resina composta. Vinte e um terceiros molares humanos recém extraídos, divididos em três grupos, receberam preparos cavitários padronizados em suas faces vestibular e lingual. As cavidades foram tratadas com Single Bond (3M) e restauradas com dois incrementos de resina composta Filtek A110 (3M). No grupo I utilizou-se luz halógena convencional QTH (40s-600mW/cm²-Optilux/Demetron/USA), no grupo II o sistema de Diodo Emissor de Luz Azul LED (40s-400mW/cm²-Elipar FreeLight/3M-ESPE) e no grupo III, o sistema de Diodo Emissor de Luz Azul LED (40s-150mW/cm²-Ultraled/Dabi-Atlante). Depois de restaurados, os dentes foram amazenados em soro fisiológico a 37°C por 24 horas, receberam polimento, ciclagem térmica em água por 500 ciclos (8°C "2°C e 55°C "2°C) e foram seccionados. As amostras obtidas foram observadas em MEV 1000X. Os resultados das médias das fendas, submetidos à análise estatística, foram: GI (1,79+- 1,79 micrômetro); GII (0,88+- 1,24 micrômetro); GIII (8,22+- 6,67 micrômetro). Após a análise de variância ANOVA, não se observou diferença estatisticamente significante entre as médias obtidas nos GI e GII (p>0.05). O GIII apresentou diferença significante entre as médias (P<0.05) quando comparado com outros grupos. Concluiu-se que nenhum sistema avaliado impediu a formação de fendas e que o sistema Elipar FreeLight/3M-ESPE apresentou o melhor desempenho