Proanthocyanidin may improve the shear bond strength at the composites/dentine interface.

TThis study aimed at assessing whether proanthocyanidin, a collagen cross-linker, affects the adhesion strength of resin composites on the dentine surface. Freshly extracted, caries-free, human molars (N=55) were embedded in transparent resin and bisected. The halves were then assigned to either a treated or a non-treated group, where the treatment consisted of a 10 min incubation in a 6.5% proanthocyanidin solution in PBS. A resin composite cylinder was polymerized perpendicularly to the dentinal surfaces and shear tests were made, using an Instron-like machine. The fracture surfaces were characterized by optical (Picro-Sirius Red stain) and electron microscopy (FESEM EDX analysis). Mean bond strength values were 10.73 MPa (SD 3.70) for the treated group and 8.69 MPa (SD 3.20) for the non-treated group (p less than 0.05 Student’s t-test). No constant fracture patterns could be found within the two groups. Proanthocyanidin treatment may improve the adhesion properties of the dentine-bonding interface.

Treatment of symptomatic oral mucositis with sodium hyaluronate and synthetic amino acid precursors of collagen in patients undergoing haematopoietic stem cell transplantation.

The purpose of the study is to evaluate the clinical effects of Mucosamin® (a spray preparation containing sodium hyaluronate combined with a pool of amino acids of precursor collagen, including L-Proline, L-Leucine, L-Lysine and glycine) on wound healing and pain management of oral mucositis after hematopoietic stem cell transplantation. The importance of professional dental hygiene by dental hygienist in reducing the severity of oral mucositis as unique therapy or in addition to therapy with Mucosamin® was also evaluated. One hundred thirty-seven patients undergoing hematopoietic stem cell transplantation were recruited in a case-control study and divided into 4 groups: Group A: professional oral hygiene + Mucosamin®; Group B: professional oral hygiene + standard treatment with chlorhexidine 0.20%;; Group C: only Mucosamin®; Group D: only standard treatment with chlorhexidine 0.20%. The following evaluations were made: WHO mucositis scale, OMAS mucositis scale, VAS, periodontal recording, days of mucositis. Comparing the groups at the onset of OM on WHO scale, it was observed that Group A grade 1 occurrence was more statistically significant than Group B (p= 0.03*); comparison between Group A and D showed a statistically significant difference in favour of Group A (p= 0.0002*). Also OMAS scale showed a statistically significant difference between groups who assumed Mucosamin, who developed lower OM grade (p = 0.001*). There was a statistically significant difference between group A compared with group B over the overall duration of OM (p = 0.02*), as well as between group A and group D (p=0.03*). According to the present study the combination of a careful debridement, correct oral hygiene during hospitalization and the use of Mucosamin® exponentially reduces the severity and duration of mucositis and consequently the discomfort of the patient. Moreover, it can be stated that the use of Mucosamin® also results in a reduction in the extent of chemotherapy lesions. Hyaluronic acid and amino acid-based sprays can be a valuable therapeutic aid in the treatment of mucositis.

Randomized, placebo-controlled, double-blind trial of clobetasol propionate 0.05% in the treatment of oral lichen planus.

OBJECTIVE: To perform a randomized, placebo-controlled, double-blind study, with a follow-up period of 6 months, for the use of topical clobetasol in cases of symptomatic oral lichen planus (OLP). SUBJECTS AND METHODS: Thirty-two participants were analyzed, with the aims of: (I) to compare the usefulness of topically applied clobetasol propionate 0.05% (mixed with 4% hydroxyethyl cellulose gel) and 4% hydroxyethyl cellulose gel alone (considered as placebo) in the management of OLP; (II) to describe which of them is quicker in decreasing signs and reported symptoms, and (III) which is able to give the proper longer remission in the follow-up. RESULTS: Symptoms improved in all clobetasol-treated patients during the first 2 months of therapy, while only 50% of placebo control group (p = .005) displayed similar results; of the remaining half, 12.5% did experienced a worsening while 37.5% remained stable. Regarding clinical signs, 87.5% of clobetasol-treated patients improved, while only 62.5% of the placebo-treated patients had a positive response (p = .229). CONCLUSIONS: It is possible to report that clobetasol, at this dosage, has been more effective than a placebo at provoking symptoms improvement in subjects affected by atrophic-erosive oral lesions.

Cytokine, Chemokine, and Growth Factor Profile Characterization of Undifferentiated and Osteoinduced Human Adipose-Derived Stem Cells.

Bone is the second most manipulated tissue after blood. Adipose-derived stem cells (ASCs) may become a convenient source of MSC for bone regenerative protocols. Surprisingly, little is known about the most significant biomolecules these cells produce and release after being osteoinduced. Therefore, the present study aimed at dosing 13 candidates chosen among the most representative cytokines, chemokines, and growth factors within the conditioned media of osteodifferentiated and undifferentiated ASCs. Two acknowledged osteoblastic cell models, that is, MG-63 and SaOs-2 cells, were compared. Notably, IL-6, IL-8, MCP-1, and VEGF were highly produced and detectable in ASCs. In addition, while IL-6 and IL-8 seemed to be significantly induced by the osteogenic medium, no such effect was seen for MCP-1 and VEGF. Overall SaOS-2 had a poor expression profile, which may be consistent with the more differentiated phenotype of SaOs-2 compared to ASCs and MG-63. Instead, in maintaining medium, MG-63 displayed a very rich production of IL-12, MCP-1, IP-10, and VEGF, which were significantly reduced in osteogenic conditions, with the only exception of MCP-1. The high expression of MCP-1 and VEGF, even after the osteogenic commitment, may support the usage of ASCs in bone regenerative protocols by recruiting both osteoblasts and osteoclasts of the host.

Use of sodium hyaluronate and synthetic amino acid precursors of collagen for the symptomatic treatment of mucositis in patients undergoing haematopoietic stem cell transplants.

Oral mucositis (OM) may occur in up to 100% of patients undergoing condition regimen to hematopoietic stem cell transplant (HSCT). From the patient’s perspective, OM is one of the most debilitating side effects of transplantation. It is commonly thought that oral hygiene can modify the incidence and severity of oral mucositis, therefore professional oral health care (POHC) is recommended prior to conditioning regimen for HSCT. A new strategy for the treatment of OM is sodium hyaluronate (SH) combined with amino acid precursors of collagen (Aas) (Mucosamin®). SH is a mucoaderent polymer acting as a mechanical barrier and pain reliever. Furthermore, it allows prolonged contact of the product with the mucous membrane. In this study, a total of 68 adult patients due to undergo HSCT for allogenic and autologous transplant were enrolled at the Stem Cell Transplant Unit. The patients were divided into two groups. One group was treated with POHC before HSCT and applications of Mucosamin® during the recovery after transplantation. The second group served as controls, with the usual treatment of Clorexidine 0.20% adopted by the department. After HSCT the same clinician, an expert in oral medicine trained for the clinical trial, evaluated symptoms of the patients’ mucositis of both groups every day. The treated patients developed less severe OM, therefore Mucosamin® seems to have a protective role against the more severe phases of mucositis. The maximum OM pain, measured with the VAS scale, was higher in patients who did not use Mucosamin®. In the treated group OM resolved sooner than in the control group.

Cytokine, chemokine, and growth factor profile of platelet-rich plasma.

During wound healing, biologically active molecules are released from platelets. The rationale of using platelet-rich plasma (PRP) relies on the concentration of bioactive molecules and subsequent delivery to healing sites. These bioactive molecules have been seldom simultaneously quantified within the same PRP preparation. In the present study, the flexible Bio-Plex system was employed to assess the concentration of a large range of cytokines, chemokines, and growth factors in 16 healthy volunteers so as to determine whether significant baseline differences may be found. Besides IL-1b, IL-1ra, IL-4, IL-6, IL-8, IL-12, IL-13, IL-17, INF-γ, TNF-α, MCP-1, MIP-1a, RANTES, bFGF, PDGF, and VEGF that were already quantified elsewhere, the authors reported also on the presence of IL-2, IL-5, IL-7, IL-9, IL-10, IL-15 G-CSF, GM-CSF, Eotaxin, CXCL10 chemokine (IP-10), and MIP 1b. Among the most interesting results, it is convenient to mention the high concentrations of the HIV-suppressive and inflammatory cytokine RANTES and a statistically significant difference between males and females in the content of PDGF-BB. These data are consistent with previous reports pointing out that gender, diet, and test system affect the results of platelet function in healthy subjects, but seem contradictory when compared to other quantification assays in serum and plasma. The inconsistencies affecting the experimental results found in literature, along with the variability found in the content of bioactive molecules, urge further research, hopefully in form of randomized controlled clinical trials, in order to find definitive evidence of the efficacy of PRP treatment in various pathologic and regenerative conditions.

Overcoming physical constraints in bone engineering: 'the importance of being vascularized'.

Bone plays several physiological functions and is the second most commonly transplanted tissue after blood. Since the treatment of large bone defects is still unsatisfactory, researchers have endeavoured to obtain scaffolds able to release growth and differentiation factors for mesenchymal stem cells, osteoblasts and endothelial cells in order to obtain faster mineralization and prompt a reliable vascularization. Nowadays, the application of osteoblastic cultures spans from cell physiology and pharmacology to cytocompatibility measurement and osteogenic potential evaluation of novel biomaterials. To overcome the simple traditional monocultures in vitro, co-cultures of osteogenic and vasculogenic precursors were introduced with very interesting results. Increasingly complex culture systems have been developed, where cells are seeded on proper scaffolds and stimulated so as to mimic the physiological conditions more accurately. These bioreactors aim at enabling bone regeneration by incorporating different cells types into bio-inspired materials within a surveilled habitat. This review is focused on the most recent developments in the organomimetic cultures of osteoblasts and vascular endothelial cells for bone tissue engineering.

Alumina-zirconia composites functionalized with laminin-1 and laminin-5 for dentistry: effect of protein adsorption on cellular response.

The present paper describes a study on laminin interaction with the surface of two alumina-zirconia composites with different percentages of ZrO2, both with submicrometric grain size. As major molecules within the basement membrane (BM), laminins are important protein fragments for epithelial cell adhesion and migration. On the other hand, alumina-zirconia composites are very attractive materials for dental applications due to their esthetic and mechanical properties. X-Ray photoelectron spectroscopy and atomic force microscopy were used to study the adsorption of two types of laminin, laminin-1 (Ln-1) and laminin-5 (Ln-5), onto the ceramics surfaces. The in vitro cell response was determined by intracellular phosphorylation of major kinases. Ceramics samples functionalized with laminins showed better cellular activation than untreated specimens; furthermore, cellular activation was found to be greater for the composite with higher percentage in zirconia when functionalized with Ln-5, whereas the adsorption of Ln-1 resulted in a greater activation for the alumina-rich oxide.

Healing properties of implants inserted concomitantly with anorganic bovine bone. A histomorphometric human study.

BACKGROUND: The present prospective, randomized, double-blind study evaluated the bone-forming process around implants inserted simultaneously with anorganic bovine bone (ABB) in sinus grafting. METHODS: A total of 18 threaded mini-implants with Osseotite (O) and Nanotite (N) surfaces were placed in seven patients (nine sites). After 12 months, the implants were retrieved and processed for histological analysis. A total of 18 cutting and grinding sections were investigated with bright-field light microscopy, circularly polarized light microscopy (CPLM), confocal scanning laser microscope (CSLM), and scanning electron microscope (SEM) with energy dispersive spectrometer (EDS). RESULTS: The bone-to-implant contact rate in native crestal bone was 62.6 ± 0.4% for N implants and 54.3 ± 0.5% for the O implants (p = 0.001). The collagen fibre density, as assessed by CPLM, was 79.8 ± 6.0 nm for the N group and 74.6 ± 4.6 nm for the O group (p < 0.05). Line scan EDS starting from ABB to newly formed bone showed a decrease in calcium content and an increase of carbon while phosphorus content was constant. CONCLUSIONS: While the N surface improved the peri-implant endosseous healing properties in the native bone, when compared to the O surface, it did not improve the healing properties in the bone-graft area.

Biological components in a standardized derivative of bovine colostrum.

Products of different origin, time of collection, and activities fall under the general term of colostrum and, therefore, great variability in composition as well as in the concentration of its components has been reported in the literature. In the present study, we describe the standardization of a bovine colostrum derivative and the characterization of its bioactive components. Evaluation of the most representative agents (lactoferrin, transferrin, IL-2, IFN-γ, tumor necrosis factor, IgG, and IgA) showed that a marked decrease in active components occurs after the first few hours. Bovine colostrum was, therefore, collected up to the fifth hour after delivery from Holstein cows, in the presence of preservatives, and immediately frozen. A protocol of centrifugation, filtration, and lyophilization was then applied to pools of colostrum from at least 30 cows to obtain a stable, sterile, standardized product. Preservatives were removed by dialysis. Evaluation of the active biological components of colostrum showed that the final product of colostrums contained significant and reproducible amounts of bioactive factors, including cytokines, immunomodulating factors, growth factors, and immunoglobulins. The final product appeared, therefore, as a sterile, pyrogen-free, standardized derivative of bovine colostrum with a high concentration of bioactive components.

Exposing human epithelial cells to zoledronic acid can mediate osteonecrosis of jaw: an in vitro model.

BACKGROUND: Osteonecrosis of the jaw (ONJ) is a chronic complication of bisphosphonate therapy, mainly when intravenous, in cancer patients with bone metastases and myeloma. Its pathophysiology is not yet fully elucidated; in particular, the molecular/cellular events triggering ONJ remain unclear. This complication could result from the effect of bisphosphonates released from bone into the soft-tissues, or from osteolysis induced by soft-tissues directly exposed to bisphosphonates. This research investigated the possibility that ONJ may be evocated by changes induced in osteoblast activity by factors released by soft-tissue cells exposed to zoledronic acid. METHODS: An 'in vitro' model was used, in which human osteoblast-like MG-63 cells were grown in medium conditioned by human keratinocytes NCTC 2544, exposed or not to zoledronic acid (5 or 50 µM); 5 µM zoledronic acid was also directly administered to MG-63 cells. RESULTS: In NCTC 2544 cells, zoledronic acid decreased proliferation via decreased hydroxy-3-methyl-glutaryl-CoA reductase, suggesting that a decrease in healing capability can occur in case of injury. An increased pro-inflammatory potential was also observed. Osteoblasts grown in medium conditioned in the presence of zoledronic acid showed decreased proliferation and osteogenic properties, and increased ability to induce osteoclast differentiation and inflammatory process. Zoledronic acid directly administered to MG-63 modulated only some parameters and in a lesser extent. CONCLUSIONS: The research evidenced, for the first time, the direct involvement of epithelial cells in zoledronic acid-triggered molecular mechanisms leading to osteonecrosis of the jaw, by modulating both osteoblast and osteoclast properties.

Transglutaminase 2 expression is significantly increased in cyclosporine-induced gingival overgrowth.

Cyclosporine A is a potent immunosuppressant used to prevent organ transplant rejection and treat various autoimmune diseases. However, cyclosporine A can also induce gingival overgrowth, which is characterized by increased extracellular matrix due to an altered balance between collagen synthesis and degradation. This study proposed to verify whether trans-glutaminase 2, an enzyme thought to be responsible for the assembly and remodelling of extracellular matrix, plays any role in the pathogenesis of cyclosporine A-induced gingival overgrowth. Cyclosporine A-induced gingival overgrowths were collected from 21 liver transplant patients and case-controlled with 20 non-hyperplastic gingival biopsies from healthy patients who had previous periodontal treatment. In both groups, the presence and tissue distribution of transglutaminase 2 were determined by immunohistochemistry and analyzed in comparison with the tissue morphology and expression of lymphocyte-related antigens (CD3 and CD20) and a vessel-related marker (CD34). Transglutaminase 2 expression showed a significant increase (2.6-fold) in the stromal component of cyclosporine A-treated patients compared with controls (p<0.001), which suggested that transglutaminase 2 had a role in the pathogenesis of the disease. Further studies should investigate the therapeutic effect of anti-transglutaminase 2 drugs (putrescine or 1,4-diamino-butane) in these patients.

Cephalometric evaluation of the upper airway in patients with complete dentures.

AIM: Obstructive sleep apnea syndrome (OSAS) is a disorder characterised by repeated obstructions of the upper airway, with consequent episodes of apnea and hypopnea during sleep, snoring, and daytime sleepiness. Recently, a role of edentulism in the occurrence or in the worsening of this disorder was suspected. The aim of the study was to assess, through a cephalometric analysis, if the removal of denture induces, and where, modifications that can favour the pharynx collapse. METHODS: A total of 27 subjects with complete or partial loss of teeth and with heavy loss of the vertical dimension, were examined. The patients were submitted to radiographs of the cranium in supine position, to simulate as much as possible the night condition, with the denture in intercuspal position (ICP), and in relaxed position both with denture (D-RP) and without it (edentule-relaxed position, E-RP). The radiographs were analysed through specific measures for OSA evaluating the parameters that could be modified by the denture. RESULTS: The pharyngeal airway space (PAS) decreases, at the level of uvula, from ICP (6.7 mm) to RP (5.3 mm) (P< 0.05). The distance between the base and the tip of the tongue significatively decreased both from ICP vs E-RP (7.35 mm vs 6.87 mm; P< 0.05), both from D-RP to E-RP (7.22 mm vs 6.87 mm; P< 0.005). CONCLUSIONS: From the data obtained from the cephalometric analysis it seems that wearing denture induces modifications in the position of the tongue, of the jaw and of the pharyngeal airway space that can favour the reduction of apnea episodes.

[In vitro evaluation of chromatic stability in new-generation composites]. / Valutazione in vitro della stabilità cromatica di materiali compositi di nuova generazione.

BACKGROUND: Ultraviolet light exposure produces chromatic changes in composites used for esthetic restoration. The aim of the study was to compare the chromatic changes induced by accelerated aging in two composites of new generation: Tetric Ceram and Diamond Crown. METHODS: Five samples were prepared for each composite, each divided into two pieces, one exposed to accelerated aging obtained by ultraviolet-light exposure for 24 hours, and one maintained in dark. Thereafter, the samples were lighted by a light beam and the percentage of reflected light was assessed. The distribution of the levels of red, green and blue was assessed using a camera connected to a PC with a software for image processing. RESULTS: For both the composites, the values of the three colors were significantly lower in the samples artificially aged (p<0.0001). The values concerning to the Tetric Ceram were significantly lower than those of Diamond Crown (p<0.0001). The latter showed aging-induced variation significantly smaller than the former. CONCLUSIONS: Both the composites showed significant chromatic variations after 24 hours artificial aging. Diamond Crown showed significantly better stability.

Influence of mastication on gastric emptying.

The role of mastication on digestion efficiency remains to be demonstrated. This study investigates whether masticatory function influences gastric emptying rate. Twelve normal volunteers were studied on two occasions after ingestion of the same test meal containing ham cubes, crackers, and egg (mixed with 13C-octanoic acid), chewed, in random order, either with 50 masticatory cycles or with 25 cycles, swallowing ham cubes whole. Lag phase (Tlag) and gastric half-emptying time (T1/2) were measured by means of the 13C-octanoic acid breath test. Trituration performance was assessed by the sieve test, and was expressed as the percentage of ham particles < or = 1 mm after 50 masticatory cycles. Tlag and T1/2 were significantly shorter when the meal was chewed with 50 cycles than with 25 cycles (Tlag 25.9+/-3.8 vs. 36.4+/-4.1 min, p=0.017; T1/2 49.1+/-5.7 vs. 62.5+/-6 min, p=0.009). Trituration performance was inversely related to both Tlag (r=0.621, p=0.031) and T1/2 (r=0.699, p=0.012). Comminution of food influences significantly gastric emptying rates.

Oral nitric oxide during plaque deposition.

BACKGROUND: Nitric oxide (NO) is one of the most powerful antibacterial compounds. We investigated if NO oral production increases during dental plaque deposition. MATERIALS AND METHODS: Oral NO and salivary nitrite were measured in 31 healthy subjects - 11 smokers and 20 nonsmokers - with natural healthy teeth, in the morning after tooth cleaning (baseline), after withdrawal of oral hygiene for 24 h and again after tooth cleaning. RESULTS: NO and nitrite were significantly higher during plaque deposition than with clean teeth: mean NO values +/- SEM were 44.3 +/- 4.9 parts per billion (ppb) at baseline, 58.8 +/- 3.7 ppb with plaque and 43.6 +/- 3.7 ppb after tooth cleaning, P < 0.05; nitrite values were 32.9 +/- 5.5 microm at baseline, 66.4 +/- 8.2 with plaque and 37.5 +/- 5.5 after tooth cleaning, P < 0.01. During plaque deposition, oral NO was significantly directly related to salivary nitrite (r = 0.497, P = 0.002) and so were their respective changes after tooth cleaning (r = 0.577, P < 0.001). Smokers had significantly lower oral NO than nonsmokers, with both clean and dirty teeth (P < 0.001), and higher bacteria counts in the plaque (38.6 +/- 11.5 vs. 19.9 +/- 2.3, P = 0.046). CONCLUSIONS: Oral NO production increases during de novo deposition of dental plaque. NO might be an early host defence mechanism against bacterial proliferation in the plaque. Such a mechanism is inhibited by cigarette smoking.

Effect of edentulism on spirometric tests.

The impact of denture wear in edentulous subjects while performing routine spirometric measurements has never been systematically investigated. We compared the values of FVC, FEV(1), PEFR, FEF(50%), FIV(1), and FIF(50%) recorded with and without dentures in three groups of edentulous subjects: 36 asymptomatic subjects with normal spirometry (N), 22 patients with chronic obstructive pulmonary disease (COPD), and 18 with interstitial lung disease (ILD). In 14 subjects retropharyngeal space with and without dentures was assessed by cephalometry. Subjects with N and ILD had significantly lower airflow rates without dentures, whereas subjects with COPD had no significant difference in spirometric values recorded with or without dentures. The retropharyngeal space was significantly decreased by removing dentures (from 1.52 +/- 0.07 to 1.16 +/- 0.09 cm, SEM, p < 0.0001). These findings indicate that in edentulous subjects with a normal or restrictive pattern, the recording of flow-volume curves with or without dentures produces small but significant differences. Although such differences do not appear to have clinical significance, the fact that when dentures are used some respiratory flows are higher would favor the use of dentures in edentulous subjects during spirometric evaluation.

Influence of posts and cores on light transmission through different all-ceramic crowns: spectrophotometric and clinical evaluation.

PURPOSE: The influence of different types of posts and cores on light transmission through all-ceramic crowns was assessed by spectrophotometric analysis and clinical evaluation. MATERIALS AND METHODS: Three extracted natural teeth were replicated in acrylic resin, with roots prepared to receive standardized posts and cores. Using a silicone impression material as a template, various prosthodontic reconstructions were obtained by combining four types of posts and cores (polished and matte-finished gold alloy, all-ceramic, and ceramized metal alloy) and three types of all-ceramic crowns (IPS-Empress 2 surface-colored, IPS-Empress 2 stratified, and In-Ceram). The spectrophotometric analysis was performed in the dark at 25 degrees C. The teeth were backlit with an incandescent lamp at the color temperature of A illuminant and shielded to avoid spurious light entering the spectrophotometer. The transmitted light was analyzed in terms of luminance at four points of the sample surface (cervical, middle, incisal, and proximal). Twelve measurements were performed for the natural teeth, and 144 were performed for the artificial teeth. RESULTS: Natural teeth had the highest luminance. Among all-ceramic crowns, surface-colored IPS-Empress 2 had the highest luminance, and stratified IPS-Empress 2 had the lowest. Regarding posts and cores, the luminance was highest with the all ceramic, lower with the ceramized and the polished gold alloy (which had very similar luminance), and lowest with the matte-finished gold alloy. No significant difference among prosthodontic combinations was detected under clinical observation. CONCLUSION: The surface-colored glass ceramic (IPS-Empress 2) was the most translucent crown. At the standard crown thickness used, there were small, significant spectrophotometric, but not clinical, differences among the combinations tested. These findings show no esthetic contraindications for the use of polished gold alloy posts and cores with all-ceramic crowns.