Mouse Wnt1-CRE-RosaTomato Dental Pulp Stem Cells Directly Contribute to the Calvarial Bone Regeneration Process.

Stem cells endowed with skeletogenic potentials seeded in specific scaffolds are considered attractive tissue engineering strategies for treating large bone defects. In the context of craniofacial bone, mesenchymal stromal/stem cells derived from the dental pulp (DPSCs) have demonstrated significant osteogenic properties. Their neural crest embryonic origin further makes them a potential accessible therapeutic tool to repair craniofacial bone. The stem cells' direct involvement in the repair process versus a paracrine effect is however still discussed. To clarify this question, we have followed the fate of fluorescent murine DPSCs derived from PN3 Wnt1-CRE- RosaTomato mouse molar (T-mDPSCs) during the repair process of calvaria bone defects. Two symmetrical critical defects created on each parietal region were filled with (a) dense collagen scaffolds seeded with T-mDPSCs, (b) noncellularized scaffolds, or (c) no scaffold. Mice were imaged over a 3-month period by microcomputed tomography to evaluate the extent of repair and by biphotonic microscopy to track T-mDPSCs. Histological and immunocytochemical analyses were performed in parallel to characterize the nature of the repaired tissue. We show that T-mDPSCs are present up to 3 months postimplantation in the healing defect and that they rapidly differentiate in chondrocyte-like cells expressing all the expected characteristic markers. T-mDPSCs further maturate into hypertrophic chondrocytes and likely signal to host progenitors that form new bone tissue. This demonstrates that implanted T-mDPSCs are able to survive in the defect microenvironment and to participate directly in repair via an endochondral bone ossification-like process. Stem Cells 2019;37:701-711.

Comparative study of debris and smear layer removal with EDTA and Er,Cr:YSGG laser.

BACKGROUND: To evaluate in vitro, the ability in removing debris and Smear Layer of 17% EDTA and Er,Cr:YSGG laser. MATERIAL AND METHODS: 58 unirradicular teeth were instrumented with MTwo® and divided into 3 groups according to irrigation protocol: 17%EDTA, laser and a combination of 17%EDTA and laser. All samples were analyzed in the apical and middle third with Scanning Electron Microscope. The Chi-cuadrado and McNemar tests were used to determine the statistical analysis and data processing and analysis was performed with the statistical package StatGraphics Centurion XVI. RESULTS: Debris analysis showed statistical significant differences when compared EDTA vs laser and EDTA vs EDTA+laser in the middle third. The Smear Layer removal showed statistical significant differences in the middle third when compared EDTA vs laser and EDTA vs EDTA+laser. CONCLUSIONS: Laser showed a greater cleaning capacity than EDTA in the middle third; the cleanliness was even better when combined laser with EDTA, so the effect is accumulative. Key words:Root canal treatment, Smear Layer, Er,Cr:YSGG laser, debridement.

Production of bone mineral material and BMP-2 in osteoblasts cultured on double acid-etched titanium

Background: The study of osteoblasts and their osteogenic functions is essential in order to understand them and their applications in implantology. In this sense, this study try to study BMP-2 production and bone matrix deposition, in addition to other biological variables, in osteoblasts cultured on a rough double acid-etched titanium surface (Osseotite®, Biomet 3i, Palm Beach Garden, Florida, USA) in comparison to a smooth titanium surface (machined) and a control Petri dish. Material and Methods: An in vitro prospective study. NHOst human osteoblasts from the femur were cultured on three different surfaces: Control group: 25-mm methacrylate dish (n = 6); Machined group: titanium discs with machined surface (n = 6) and Experimental group: titanium discs with a double acid-etched nitric and hydrofluoric Osseotite® acid surface (n = 6). A quantification of the mitochondrial membrane potential, and studies of apoptosis, mobility and adhesion, bone productivity (BMP-2) and cellular bone synthesis were carried out after culturing the three groups for forty-eight hours. Results: A statistically significant difference was observed in the production of BMP-2 between the experimental group and the other two groups (22.33% ± 11.06 vs. 13.10% ± 5.51 in the machined group and 3.88% ± 3.43 in the control group). Differences in cellular bone synthesis were also observed between the groups (28.34% ± 14.4% in the experimental group vs. 20.03% ± 6.79 in the machined group and 19.34% ± 15.93% in the control group). Conclusions: In comparison with machined surfaces, Osseotite® surfaces favor BMP-2 production and bone synthesis as a result of the osteoblasts in contact with it (AU)

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Effectiveness of flossing loops in the control of the gingival health.

BACKGROUND: One of the key factor in the good condition of periodontal tissues is their daily hygiene. Oral hygiene techniques such brushing and a good interdental hygiene by correct flossing are very important. The aim of this study is to compare the use of dental floss in a loop vs traditional floss in the control of Loe-Silness Gingival Index (IG), Turesky´s Plaque Index (IPT), Gingival Bleeding Index (IS) and the values of interleukin 6 (IL-6) and interleukin 8 (IL-8). MATERIAL AND METHODS: A comparative study of 40 patients in which each patient was his own control, using during 45 days each one of the devices (new loop floss and conventional floss) of interdental hygiene analysed. Data for Loe-Silness Gingival Index (IG), Turesky´s Plaque Index (IPT), Gingival Bleeding Index (IS) and the values of interleukin 6 (IL-6) and interleukin 8 (IL-8)were collected and measured in every visit for every type of interdental hygiene device. RESULTS: Our data indicates that the rate of Turesky´s Plaque Index presented statistically significant differences between groups (loop: 1.66 ± 0.8; traditional: 1.12 ± 0.8; p<0.0001). The rest of the indices studied showed no statistically significant differences. CONCLUSIONS: The creation of new dental floss designs try to make their use easier and more sensitive, and plaque removal more effective. The loop design can facilitate interdental hygiene, reaching similar effectiveness than traditional floss, improving some indicators, such as Turesky´s Plaque Index. Key words:Dental floss, bacterial plaque, loop floss, plaque index, periodontal diseases.

Ability of salivary biomarkers in the prognostic of systemic and buccal inflammation.

Nowadays, there is a growing interest in using saliva as an alternative sample for the diagnosis, prediction and progression of several diseases. It has been established that some molecules found in saliva are related to oral inflammatory processes and systemic health status. Furthermore, it is known that saliva is crucial for the carrying out of different functions in the oral cavity and its role in the local modulation of inflammatory and immune response is being thoroughly studied by the health research community. The aim of this review is to analyze the most important biomarkers which have been utilized in biomedicine during the last two decades in order to establish a correlation between certain specific salivary biomarkers and systemic inflammation. Then, we discuss the utility of total proteins, immunoglobulin A and alpha-amylase as biomarkers for the prognostic of local inflammation after oral surgery. Key words:Inflammation, salivary biomarkers, systemic disease, buccal surgery, total proteins, inmunoglobulin A, Alpha-amylase.

‘Reliability of new poly (lactic-co-glycolic acid) membranes treated with oxygen plasma plus silicon dioxide layers for pre-prosthetic guided bone regeneration processes’

BACKGROUND: The use of cold plasmas may improve the surface roughness of poly(lactic-co-glycolic) acid (PLGA) membranes, which may stimulate the adhesion of osteogenic mediators and cells, thus accelerating the biodegradation of the barriers. Moreover, the incorporation of metallic-oxide particles to the surface of these membranes may enhance their osteoinductive capacity. Therefore, the aim of this paper was to evaluate the reliability of a new PLGA membrane after being treated with oxygen plasma (PO2 ) plus silicon dioxide (SiO2 ) layers for guided bone regeneration (GBR) processes. MATERIAL AND METHODS: Circumferential bone defects (diameter: 11 mm; depth: 3 mm) were created on the top of eight experimentation rabbits' skulls and were randomly covered with: (1) PLGA membranes (control), or (2) PLGA/ PO2 /SiO2 barriers. The animals were euthanized two months afterwards. A micromorphologic study was then performed using ROI (region of interest) colour analysis. Percentage of new bone formation, length of mineralised bone, concentration of osteoclasts, and intensity of ostheosynthetic activity were assessed and compared with those of the original bone tissue. The Kruskal-Wallis test was applied for between-group com a significance level of a=0.05 was considered. RESULTS: The PLGA/PO2 /SiO2 membranes achieved the significantly highest new bone formation, length of mineralised bone, concentration of osteoclasts, and ostheosynthetic activity. The percentage of regenerated bone supplied by the new membranes was similar to that of the original bone tissue. Unlike what happened in the control group, PLGA/PO2 /SiO2 membranes predominantly showed bone layers in advanced stages of formation. CONCLUSIONS: The addition of SiO2 layers to PLGA membranes pre-treated with PO2 improves their bone-regeneration potential. Although further research is necessary to corroborate these conclusions in humans, this could be a promising strategy to rebuild the bone architecture prior to rehabilitate edentulous areas

'Pre-prosthetic use of poly(lactic-co-glycolic acid) membranes treated with oxygen plasma and TiO2 nanocomposite particles for guided bone regeneration processes'.

OBJECTIVES: Guided bone regeneration (GBR) processes are frequently necessary to achieve appropriate substrates before the restoration of edentulous areas. This study aimed to evaluate the bone regeneration reliability of a new poly-lactic-co-glycolic acid (PLGA) membrane after treatment with oxygen plasma (PO2) and titanium dioxide (TiO2) composite nanoparticles. METHODS: Circumferential bone defects (diameter: 10mm; depth: 3mm) were created on the parietal bones of eight experimentation rabbits and were randomly covered with control membranes (Group 1: PLGA) or experimental membranes (Group 2: PLGA/PO2/TiO2). The animals were euthanized two months afterwards, and a morphologic study was then performed under microscope using ROI (region of interest) colour analysis. Percentage of new bone formation, length of mineralised bone formed in the grown defects, concentration of osteoclasts, and intensity of osteosynthetic activity were assessed. Comparisons among the groups and with the original bone tissue were made using the Kruskal-Wallis test. The level of significance was set in advance at a=0.05. RESULTS: The experimental group recorded higher values for new bone formation, mineralised bone length, and osteoclast concentration; this group also registered the highest osteosynthetic activity. Bone layers in advanced formation stages and low proportions of immature tissue were observed in the study group. CONCLUSIONS: The functionalised membranes showed the best efficacy for bone regeneration. CLINICAL SIGNIFICANCE: The addition of TiO2 nanoparticles onto PLGA/PO2 membranes for GBR processes may be a promising technique to restore bone dimensions and anatomic contours as a prerequisite to well-supported and natural-appearing prosthetic rehabilitations.

Importance of Poly(lactic-co-glycolic acid) in Scaffolds for Guided Bone Regeneration: A Focused Review.

Total or partial tissue damage and loss of function in an organ are two of the most serious and costly issues in human health. Initially, these problems were approached through organ and allogenic tissue transplantation, but this option is limited by the scarce availability of donors. In this manner, new bone for restoring or replacing lost and damaged bone tissue is an important health and socioeconomic necessity. Tissue engineering has been used as a strategy during the 21st century for mitigating this need through the development of guided bone regeneration scaffold and composites. In this manner, compared with other traditional methods, bone tissue engineering offers a new and interesting approach to bone repair. The poly-α-hydroxy acids, which include the copolymers of lactic acid and glycolic acid, have been used commonly in the fabrication of these scaffolds. The objective of our article was to review the characteristics and functions of scaffold with biomedical applications, with special interest in scaffold construction using poly(lactic-co-glycolic acid) polymers, in order to update the current methods used for fabrication and to improve the quality of these scaffolds, integrating this information into the context of advancements made in tissue engineering based on these structures. In the future, research into bone regeneration should be oriented toward a fruitful exchange between disciplines involved in tissue engineering, which is coming very close to filling the gaps in our ability to provide implants and restoration of functionality in bone tissue. Overcoming this challenge will provide benefits to a major portion of the population and facilitate substantial improvements to quality of life.

Influence of state anxiety and trate anxiety in postoperative in oral surgery

INTRODUCTION: The aim of this article was to study the influence of anxiety (both state and trait) in postoperative recovery after extraction of third molar together, to establish the role of each of the aspects of anxiety in the results you obtained in an independent and complementary way. MATERIAL AND METHODS: We performed a prospective study of a consecutive series of 88 patients who underwent lower third molar extractions. Before being provided with any information about the operation, patients were asked to complete the Spielberger State-Trait Anxiety Inventory-Trait and State. We have evaluated postoperative swelling and pain, patients completed a 10-point visual analog scale (VAS) at home each day (at approximately the same time of day as the operation) until day 8 after surgery, when the sutures were removed. RESULTS: Regarding postoperative variables between positive and negative trait anxiety groups, consumption of analgesic drugs was higher in positive trait anxiety group in a statistically significant way, while these differences were detected only on specific occasions regarding pain and swelling. DISCUSSION: In the present study, anxiety was taken into account and showed a significant effect in explaining postoperative pain and taking analgesics

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In vivo comparative model of oxygen plasma and nanocomposite particles on PLGA membranes for guided bone regeneration processes to be applied in pre-prosthetic surgery: a pilot study.

OBJECTIVES: To evaluate the bone regeneration potential of a new membrane fabricated with polyglycolide acid (PLGA) after being treated with oxygen plasma (PO2), and/or being functionalized with silicon dioxide (SiO2) or titanium dioxide (TiO2) nanoparticles. METHODS: Bone defects (5 mm 3 mm) were produced on the top of 3 experimentation rabbits' skulls and were covered with variously modified PLGA scaffolds. After the animals were sacrificed, neoformed bone (%), mineralized bone (mm), bone resorption (%), osteoclasts/mm2, and intensity of osteosynthetic activity, were assessed under microscope. RESULTS: The following groups were formed depending on the type of membrane: PLGA (control); PLGA/PO2; PLGA/SiO2; PLGA/TiO2; PLGA/PO2/SiO2; and PLGA/PO2/TiO2. The histological sections showed bone layers in advanced stages of formation. The highest percentages of neoformed bone corresponded to PLGA/PO2/SiO2 membranes (59.07%; p = 0.31) followed by PLGA/PO2 barriers (50.27%). The controls showed the lowest mineralization (13.89 mm; p = 0.24). PLGA/TiO2 scaffolds exhibited the least bone resorption (4.45%; p = 0.77) and osteoclasts/ mm2 (1.58; p = 0.86). PLGA/SiO2 and PLGA/TiO2 membranes stimulated the maximum osteosynthetic activity. CONCLUSIONS: The treatment of PLGA barriers with PO2 increased bone regeneration in rabbits. When comparing the effect of PO2/SiO2 and PO2/TiO2, higher percentages of neoformed bone were encountered after silicon-dioxide coating. CLINICAL SIGNIFICANCE: The incorporation of SiO2 nanoparticles onto PO2-treated PLGA membranes was the most promising technique out of those investigated to promote bone formation in rabbits. The addition of SiO2 or TiO2 layers to PLGA substrates may stimulate the osteosynthetic activity, which might be useful to restore bone dimensions in preparation for naturally appearing dental prostheses.

Effect of the Nd:YAG laser on sealer penetration into root canal surfaces: a confocal microscope analysis.

OBJECTIVES: The objective of this in vitro study was to evaluate the use of the Neodymium:Yttrium-Aluminium-Garnet (Nd:YAG) laser as part of the root canal treatment on the penetration of sealer into dentinal tubules. METHODS: Eighty extracted lower premolars were randomly assigned to two groups (n=40 each): Control group (CG), subjected to a conventional protocol of endodontic instrumentation and obturation; and Laser group (LG), in which Nd:YAG laser irradiations were combined with conventional preparation and obturation. Endodonted samples were sectioned at 3 and 5 mm from the apex and observed under a confocal scanning microscope (CLSM). The penetration depth into the dentinal tubules and the extension of the intracanal perimeter infiltrated by sealer were measured. The Student-Newman-Keuls test was run for between-group comparisons (α=.05). RESULTS: The depth of sealer penetration into dentinal tubules did not differ among groups. LG samples showed the significantly highest percentage of penetrated perimeter at 3 mm from the root apex. Within each group, the greatest depth of penetration (P=.0001), and the major percentage of penetrated perimeter (P<.001), were recorded at 5 mm. CONCLUSIONS: The application of the Nd:YAG laser after instrumentation did not improve the depth of sealer penetration into the dentinal tubules. The laser enlarged the total penetrable perimeter near the apex. CLINICAL SIGNIFICANCE: The Nd:YAG laser may be an appropriate complement in root canal treatment, as it enhances the sealer adaptation to the dentinal walls in the proximity of the apex.

Influence of state anxiety and trate anxiety in postoperative in oral surgery.

INTRODUCTION: The aim of this article was to study the influence of anxiety (both state and trait) in postoperative recovery after extraction of third molar together, to establish the role of each of the aspects of anxiety in the results you obtained in an independent and complementary way. MATERIAL AND METHOD: We performed a prospective study of a consecutive series of 88 patients who underwent lower third molar extractions. Before being provided with any information about the operation, patients were asked to complete the Spielberger State-Trait Anxiety Inventory- Trait and State. We have evaluated postoperative swelling and pain, patients completed a 10-point visual analog scale (VAS) at home each day (at approximately the same time of day as the operation) until day 8 after surgery, when the sutures were removed. RESULTS: Regarding postoperative variables between positive and negative trait anxiety groups, consumption of analgesic drugs was higher in positive trait anxiety group in a statistically significant way, while these differences were detected only on specific occasions regarding pain and swelling. DISCUSSION: In the present study, anxiety was taken into account and showed a significant effect in explaining postoperative pain and taking analgesics.