Evaluation of the active concentration of two disinfectants based on glutaraldehyde and benzalkonium chloride and antimicrobial activity in vitro against Salmonella Heidelberg and Salmonella Typhimurium

Biosecurity, cleaning and disinfection of swine and poultry facilities are fundamental for the reduction of pathogenic microorganisms of importance for public and animal health. The objective of this work was to compare the levels of active ingredient described on the label and the real levels detected in high-performance liquid chromatography (HPLC) of two disinfectants., then evaluate the antimicrobial activity since, following the Germicidal Sanitizing Action and Disinfectant Detergent (Official Method AOAC 960.09) in four different dilutions with the presence of 3% organic matter during 15 min of contact, against Salmonella Heidelberg and Salmonella Typhimurium (ST). The product "A" presents active levels of agreement according to the label. The content of quantified assets for product "B" was lower than that recorded on the label. The disinfectant "A" was effective in microbiological evaluation while the disinfectant "B" had microbiocidal activity compromised by the deficit of assets.

Adventitial Collagen Crosslink Reduces Intimal Hyperplasia in a Rabbit Arteriovenous Graft Model.

BACKGROUND: Intimal hyperplasia (IH) is the initial lesion of vein graft failure after coronary artery bypass grafting. The weak venous wall is likely one of the primary reasons for IH after exposure to the arterial environment. We investigate whether adventitial collagen cross-link by glutaraldehyde (GA) reinforces the venous wall and then reduces IH. MATERIALS AND METHODS: Adventitial collagen cross-link by 0.3% GA was performed on the rabbit jugular veins. The degree of cross-link was accessed by tensile test. The jugular vein with or without cross-link was implanted into the carotid artery of rabbit. Vein dilatation at the immediate anastomosis and pathological remodeling of vein graft after 4 wk was assessed. RESULTS: Tensile test indicated that the mechanical property of 3-min cross-linked veins more closely resembled that of the carotid artery. In rabbit arteriovenous graft models, 3-min adventitial collagen cross-link limited overdistension (diameter: 3.24 mm versus 4.65 mm, P < 0.01) at the immediate anastomosis and reduced IH (intima thickness: 78.83 µm versus 140.19 µm, P < 0.01) of vein grafts 4 wk after implantation in the cross-link group as compared with the graft group (without cross-link). Compared with the cross-link group, the expression of proliferating cell nuclear antigen and vascular cell adhesion molecule-1 increased significantly at both the mRNA and protein levels within the graft group (P < 0.01), but the expression of smooth muscle-22α decreased significantly (P < 0.01). CONCLUSIONS: Adventitial collagen cross-link by GA increased the vessel stiffness and remarkably reduced IH in a rabbit arteriovenous graft model.

Diepoxy- Versus Glutaraldehyde-Treated Xenografts: Outcomes of Right Ventricular Outflow Tract Reconstruction in Children.

BACKGROUND: Xenografts used for right ventricular outflow tract (RVOT) reconstruction are typically treated with glutaraldehyde. However, potential benefit of epoxy treatment was demonstrated in experimental studies. We aimed to compare diepoxy-treated bovine pericardial valved conduits (DE-PVCs) and glutaraldehyde-treated bovine pericardial valved conduits (GA-PVCs) for RVOT reconstruction in pediatric patients. METHODS: Between 2002 and 2017, 117 patients underwent RVOT reconstruction with PVC in single center: DE-PVC group, n = 39; and GA-PVC group, n = 78. After performing propensity score analysis (1:1) for the entire sample, 29 patients from the DE-PVC group were matched with 29 patients from the GA-PVC group. RESULTS: There were no conduit-related deaths. In the DE-PVC group, the freedom from conduit failure was 90.9% at four years and 54.3% at eight years postoperatively. In the GA-PVC group, it was 46.3% and 33.1%, respectively. The difference was significant (P = .037). Conduit failure was typically caused by stenosis in both groups. In the DE-PVC group, the main cause of stenosis was xenograft calcification (27.6%); while in the GA-PVC group, it was mostly due to neointimal proliferation (25.0%) and, less often, calcification (14.3%). Conduit thrombosis was the cause of replacement in 6.9% of patients from the GA-PVC group. CONCLUSIONS: Diepoxy-treated bovine pericardial valved conduit is a suitable alternative to GA-PVC for RVOT reconstruction in pediatric patients. Diepoxy-treated bovine pericardial valved conduits may be less prone to conduit failure and more resistant to neointimal proliferation and conduit thrombosis than GA-PVCs.

Comparative analysis and properties evaluation of gelatin microspheres crosslinked with glutaraldehyde and 3-glycidoxypropyltrimethoxysilane as drug delivery systems for the antibiotic vancomycin.

In the present comparative study, gelatin microspheres (GMs) were prepared by emulsification-solvent-extraction method using well-known crosslinker: glutaraldehyde (GA) and biocompatible silane-coupling agent: glycidoxypropyltrimethoxysilane (GPTMS). Crosslinking with GA was done by a definite and common procedure, while GPTMS crosslinking potency was investigated after 5, 10, 24, and 48 h synthesis periods and the fabrication method was adjusted in order for preparation of GMs with optimized morphological and compositional characteristics. The prepared GMs were then evaluated and compared as drug delivery systems for the antibiotic vancomycin (Vm). Morphological observations, FTIR, ninhydrin assay, swelling behavior evaluation and Hydrolytic degradation analysis proved successful modification of GMs and revealed that increasing synthesis time from 5 h to 24 h and 48 h, when using GPTMS as crosslinker, led to formation of morphologically-optimized GMs with highest crosslinking degree (∼50%) and the slowest hydrolytic degradation rate. Such GMs also exhibited most sustained release period of Vm. The antibacterial test results against gram-positive bacterium Staphylococcus aureus, were in accordance with the release profiles of Vm, as well. Together, GPTMS-crosslinked GMs with their preferable characteristics and known as biocompatible gelatin-siloxane hybrids, could act as proper drug delivery systems for the sustained release of the antibiotic vancomycin.

Calcitonin as an anticalcification treatment for implantable biological tissues.

BACKGROUND AND AIM OF THE STUDY: Calcification remains the major role of failure of implantable biomedical material and in particular of bioprosthetic valves. Various treatments have been proposed to mitigate calcification of glutaraldehyde-fixed bioprosthetic valves but none have succeeded in inhibiting or mitigating efficiently the calcification process of the implantable biological tissues. Since the discovery of calcitonin (CT) and its therapeutic role in treating hypercalcemic patients, CT has never been tried as an anticalcification treatment for biomaterials. It is postulated, that tissue calcification may be efficiently minimized by forming adducts with aldehyde groups thus eliminating the places of the biological tissues onto the calcium cations could be deposited. MATERIAL AND METHODS: Fresh porcine aortic leaflets were cut radially in three parts. Three groups of tissue were created. Group I (glutaraldehyde only), Group II (glutaraldehyde with 1% CT) and Group III (glutaraldehyde with 10% CT). All tissues were then implanted subdermally in three sets of 8 (Group I) and 9 (Group II and Group III) male Wistar rats of 12 days old. 21 days later the rats were euthanized by inhalation of CO2. The tissues were retrieved and after rinsing with distilled water 3 times, were lyophilized at -40°C at high vacuum pressure of approximately 100mmHg for 16h. The calcium content was then measured with flat atomic absorption technique. RESULTS: The preimplantation values of Ca concentration as expressed in mg Ca/g of tissue were 1.79±0.14 in Group I, 4.78±0.0079 in Group II and 2.88±0.17 in Group III (p=ns). 21 days later the values of Ca concentration were 126.95±12.97 for Group I, 24.69±2.71 for Group II (p<0.05) and 27.16±2.95 for Group III (p<0.05). There was not significance difference between Groups II and III, even if Group II showed a less accumulation of Ca concentration (×5.16) than Group III (×9.43). CONCLUSION: An anticalcification treatment based on calcitonin as an additive to buffered glutaraldehyde, mitigates the calcification process of the implantable biological tissues, as compared to glutaraldehyde treatment only.

Gelatin Porous Scaffolds as Delivery Systems of Calcium Alendronate.

The systemic administration of bisphosphonates (BPs) for the treatment of metabolic diseases characterized by abnormal bone loss suffers from several adverse side effects, which can be reduced by implementation of alternative modes of administration. In this work, glutaraldehyde cross-linked gelatin scaffolds are proposed as delivery systems of calcium alendronate monohydrate (CaAL•H2 O). The 3D highly porous scaffolds display a relevant interconnected porosity (>94%), independently from CaAL•H2 O content (0, 3, and 6 wt%). At variance, pore size varies with composition. The relative increase of the number of smaller pores on increasing BP content is in agreement with the parallel significant increase of the compressive modulus and collapse strength. The scaffolds exhibit a sustained CaAL•H2 O release profile, and a significant amount of the drug is retained in the scaffolds even after 14 d. In vitro tests are carried out using cocultures of osteoblast (OB) and osteoclast (OC). The evaluation of differentiation markers is performed both on the supernatants of cell culture and by means of quantitative polymerase chain reaction. The results indicate that BP containing scaffolds support osteoblast proliferation and differentiation, whereas they inhibit osteoclast viability and activity, displaying a promising beneficial role on bone repair processes.

Improved application technique of albumin-glutaraldehyde glue for repair of superficial lung defects.

BACKGROUND: Albumin-glutaraldehyde glue has gained widespread acceptance for treatment of alveolar air leaks (AAL) in thoracic surgery. As liquid run-off during application is detrimental to its sealing efficacy, we developed a modified technique and assessed it in vitro. METHODS: Caudal lobes of freshly excised swine lungs (n = 20) were intubated and ventilated. A standardized focal superficial parenchymal defect (40 × 25 mm) was created on the inflated lung. AAL was assessed under exposure to increasing inspired tidal volume (TVi). Lung lobes were randomly selected and subjected to either a standard sealing suggested by the manufacturer (control group) or a modified technique relying on placement of a square silicone frame around the lesion site (study group). AAL was subsequently assessed until burst failure occurred and the occuring lesions length was recorded on the inflated lung to evaluate elasticity of underlying tissue. RESULTS: Superficial parenchymal defects resulted in AAL increasing with ascending TVi. AAL prior to sealant application was comparable in both groups. An application error occurred once in our control group. At TVi = 400, 500, 600 and 700 ml, the albumin-glutaraldehyde glue achieved complete sealing in 10, 10, 9 and 8 lungs respectively in our study group, as opposed to 9, 7, 6 and 4 lobes in the control group. The required mean burst pressure was significantly higher in our study group (41.0 ± 1.0 vs. 37.5 ± 4.2 cmH2O, p = 0.0195), but there was no difference in expansion of covered defect between both groups (1.0 ± 0.4 vs. 1.5 ± 1.7 mm, p = 0.3772). CONCLUSIONS: Our tests suggest that frame-assisted sealant application might prevent glue run-off and thus improves its sealing efficacy. We encourage further investigation of this technique in well-designed, controlled clinical trials.

Albumin-glutaraldehyde glue for repair of superficial lung defect: an in vitro experiment.

BACKGROUND: Albumin-glutaraldehyde glue gained a widespread acceptance in repair of superficial lung defects associated with alveolar air leaks (AAL). As its sealing efficacy has not yet been thoroughly corroborated by clinical studies, we sought to assess the properties of commercially available albumin-glutaraldehyde glue (BioGlue™) in an in vitro lung model. METHODS: The lower lobe of freshly excised swine lung (n = 10) was intubated and ventilated. A focal superficial parenchymal defect (40 × 25 mm) was created on the inflated lung. AAL was assessed with increasing inspired tidal volume (TVi). After glue application, AAL was assessed until burst failure occurred. To evaluate glue elasticity, the length of defect was recorded in the inflated lung. RESULTS: Superficial parenchymal defects resulted in AAL increasing with ascending TVi. Multiple linear regression analysis revealed strong correlation between AAL and maximal inspiratory pressure. There was one application error. At TVi = 400, 500, 600, 700, 800 and 900 ml, BioGlue™ achieved complete sealing in nine, six, five, four two and one specimens, respectively. Mean burst pressure was 38.0 ± 4.2 cmH2O. All sealant failures were cohesive. BioGlue™ allowed an expansion of covered lung defects of 1.5 ± 1.7 mm. CONCLUSIONS: Our in vitro tests demonstrated a high sealing efficacy of BioGlue™ for repair of superficial lung defects. Due to the rigid nature, caution should be taken to use this kind of sealant in trapped lungs.

Albumin Nanoparticles for Brain Delivery: A Comparison of Chemical versus Thermal Methods and in†vivo Behavior.

Human serum albumin nanoparticles (NPs) have gained considerable attention owing to their high loading capacity for various drugs and the fact that they are well tolerated. The aim of this work was to investigate two different methods to produce NPs without the use of organic solvents and to obtain useful drug-delivery systems to cross the blood-brain barrier. NPs were obtained by coacervation, using both chemical and thermal cross-linking processes. They were developed and optimized to target brain tissues after parenteral administration in healthy rats. Furthermore, their distribution, cellular uptake, and fate were investigated in vivo after intracerebral injection in healthy rats. The toxicity of the developed carriers was estimated by behavioral tests. All NPs were chemically and physically characterized by dynamic light scattering, transmission electron microscopy, and high-performance liquid chromatography coupled with diode array and fluorimetric detectors. Their distribution and fate in the brain were evaluated by fluorescence microscopy. NPs were observed to be located in different brain tissues depending on the mode of injection, and did not induce an inflammatory response. Behavioral tests demonstrated no locomotor, explorative, or cognitive function impairment induced by the NPs.

Cutaneous biocompatible rutin-loaded gelatin-based nanoparticles increase the SPF of the association of UVA and UVB filters.

The encapsulation of natural ingredients, such as rutin, can offer improvements in sun protection effectiveness. This strategy can provide enhanced flavonoid content and produces an improved bioactive compound with new physical and functional characteristics. As an alternative to common synthetic-based sunscreens, rutin-entrapped gelatin nanoparticles (GNPs) were designed and associated with ethylhexyl dimethyl PABA (EHDP), ethylhexyl methoxycinnamate (EHMC) and methoxydibenzoylmethane (BMDBM) in sunscreen formulations. The purpose of this study was to develop rutin-loaded gelatin nanoparticles and characterize their physicochemical, thermal, functional and safety properties. Rutin-loaded gelatin nanoparticles increased antioxidant activity by 74% relative to free-rutin (FR) solution. Also, this new ingredient upgraded the Sun Protection Factor (SPF) by 48%, indicating its potential as a raw material for bioactive sunscreens. The safety profile indicated that GNPs and glutaraldehyde (GTA) decreased HaCaT cell viability in a concentration/time-dependent manner. However, both blank nanoparticles (B-NC) and rutin-loaded nanoparticles (R-NC) had good performance on skin compatibility tests. These results functionally characterized rutin-loaded nanoparticles as a safe SPF enhancer in sunscreens, especially in association with UV filters.

Clinical evaluation of low-power laser and a desensitizing agent on dentin hypersensitivity.

The aim of this randomized, longitudinal clinical study was to evaluate different protocols for dentin hypersensitivity treatment with low-power laser at different dosages, desensitizing agent, and associations, for a period of 6 months. After analysis of the inclusion and exclusion criteria of volunteer participants, those who present pain resulting from non-carious cervical lesions were selected. Twenty-seven patients participated in the study, and 55 lesions were recorded. The lesions were divided into five groups (n = 11), treated, and evaluated: G1: Gluma Desensitizer (Heraeus); G2: low-power laser (Photon Lase, DMC) at low dose (three vestibular points and one apical point of irradiation: 30 mW, 10 J/cm(2), 9 s per point with wavelength of 810 nm), three sessions were performed with an interval of 72 h between them; G3: low-power laser at high dose (application at one cervical and one apical point: 100 mW, 90 J/cm(2), 11 s per point with wavelength of 810 nm), three sessions were performed with an interval of 72 h between irradiations; G4: low-power laser at low dose + Gluma Desensitizer; and G5: low-power laser at high dose + Gluma Desensitizer, the level of sensitivity of each volunteer was evaluated with a visual analog scale of pain (VAS) with the use of air from a triple syringe and exploration with a probe after time intervals of 5 min, 1 week, and 1, 3, and 6 months after treatment. Data were collected and subjected to statistical analysis. Kolmogorov-Smirnov test was used to verify the distribution of the data, and nonparametric Kruskal-Wallis and Friedman tests were performed for comparison among the experimental groups and time intervals studied, respectively. Statistically significant differences between the studied time intervals (p < 0.05) were detected. From the difference in pain, it was observed that for both stimuli, the protocol with the Gluma desensitizing agent presented immediate effects of pain reduction. For low-level lasers, it was observed that there were distinct effects for the different doses; however, both were efficient in reducing pain up to the 6 months of clinical follow-up. Therefore, it could be concluded that all the desensitizing protocols were effective in reducing dentin hypersensitivity, but with different effects. The combination of protocols is an interesting alternative in the treatment of cervical dentin hypersensitivity.

[Preparation and quality evaluation of microcapsules of volatile oil from Ledum palustre].

OBJECTIVE: To study the preparation of microcapsules of volatile oil from Ledum palustre and its quality evaluation. METHODS: The microcapsules were prepared by complex coacervation with encapsulation efficiency as evaluation index, and the preparation was optimized by orthogonal experimental design. RESULTS: The optimum condition of microcapsules prepared was that 5% gelatin and gum arabic was material, with core material ratio of 1: 2; pH 4.0 and glutaraldehyde in an amount of 1.0 mL. The average encapsulation efficiency of microcapsules of volatile oil from Ledum palustre was 79.62%. Microcapsules was distributed evenly without adhesion through microscopic observation and more than 73% of the microcapsule size distribution between 10 - 14 microm. Microcapsules was spherical and the surface folded by using electron microscope scanning. The test solution and reference solution appeared same spot in the same location compared with the negative control solution. CONCLUSION: The preparation process is simple, stable and feasible.

Water footbath, automatic flushing, and disinfection to improve the health of bovine feet.

Disinfecting footbaths are used to treat and prevent interdigital dermatitis (ID) and heel horn erosion (HHE). However, many disinfectants are disadvantageous for the environment and, as an alternative, washing of the feet has been introduced. Our aim was to investigate the effect of water footbaths (trial 1), footbaths with CuSO4 (trial 2), automatic water flushing (trial 3), and water flushing followed by disinfection with a glutaraldehyde-based compound (trial 4) in 4 randomized controlled clinical trials performed in a freestall dairy herd of approximately 45 Norwegian Red cows. At trimming before and after each trial, hind foot diseases, hardness of the claw horn (in D-units), locomotion, and cleanliness of the claws were recorded. Before each trial, the cows were divided in comparable study and control groups, based on prevalence of ID and HHE, parity, and days in milk. Using a transponder-regulated gate, the study groups were led through a footbath (trials 1 and 2) or an automatic washer (trials 3 and 4), whereas the control groups were left untreated. Each trial lasted 3 mo and the curative effect in diseased cows and the preventive effect in cows with healthy feet on ID, HHE, and ID + HHE were analyzed. In trial 2, a preventive effect of CuSO4 on HHE compared with the untreated cows was observed. During trial 1, 100% (11/11) of the treated cows with ID got better and 22% (2/9) without ID became diseased, whereas 92% (11/12) of the treated cows with ID + HHE got better and 38% (3/8) without ID + HHE became diseased. During trial 2, 69% (9/13) of the treated cows with ID got better and 11% (1/9) without ID became diseased. During trial 4, 19% (3/16) of the untreated cows with ID + HHE got better and 71% (5/7) without ID + HHE became diseased. In trial 3, no significant effects on ID, HHE, or ID + HHE were revealed. In trial 2 (CuSO4), the treated cows' claw horn was harder after the trial compared with the controls (D-unit difference: 13.25). In trial 3 (stationary water flushing) the treated cows' claw horn was softer after the trial when compared with the controls (D-unit difference: -15.66). The CuSO4 footbaths were useful to prevent HHE and indicate that automatic stationary flushing with only water had no beneficial effect on ID or HHE. The claw horn of cows walking through CuSO4 became harder and the claw horn of cows that had their hind feet flushed with water became softer compared with the controls.

Preparation and characterization of gelatin-based mucoadhesive nanocomposites as intravesical gene delivery scaffolds.

This study aimed to develop optimal gelatin-based mucoadhesive nanocomposites as scaffolds for intravesical gene delivery to the urothelium. Hydrogels were prepared by chemically crosslinking gelatin A or B with glutaraldehyde. Physicochemical and delivery properties including hydration ratio, viscosity, size, yield, thermosensitivity, and enzymatic degradation were studied, and scanning electron microscopy (SEM) was carried out. The optimal hydrogels (H), composed of 15% gelatin A175, displayed an 81.5% yield rate, 87.1% hydration ratio, 42.9 Pa·s viscosity, and 125.8 nm particle size. The crosslinking density of the hydrogels was determined by performing pronase degradation and ninhydrin assays. In vitro lentivirus (LV) release studies involving p24 capsid protein analysis in 293T cells revealed that hydrogels containing lentivirus (H-LV) had a higher cumulative release than that observed for LV alone (3.7-, 2.3-, and 2.3-fold at days 1, 3, and 5, resp.). Lentivirus from lentivector constructed green fluorescent protein (GFP) was then entrapped in hydrogels (H-LV-GFP). H-LV-GFP showed enhanced gene delivery in AY-27 cells in vitro and to rat urothelium by intravesical instillation in vivo. Cystometrogram showed mucoadhesive H-LV reduced peak micturition and threshold pressure and increased bladder compliance. In this study, we successfully developed first optimal gelatin-based mucoadhesive nanocomposites as intravesical gene delivery scaffolds.

Pharmaceutical and medical aspects of hyaluronic acid-ketorolac combination therapy in osteoarthritis treatment: radiographic imaging and bone mineral density.

The objective of this study was to formulate novel painless combined hyaluronic acid (HA)-ketorolac (KT) membrane for the management of osteoarthritis with rapid analgesic onset, thus avoiding HA frequent invasive intra-articular injections and KT gastrointestinal complaints associated with all non-steroidal anti-inflammatory drugs. HA was chemically crosslinked with carbodiimide/glutaraldehyde to yield membrane of low water content. Different in vitro aspects (mechanical properties, water content and in vitro release) were studied leading to an optimized soft, flexible K8 HA membrane containing 30 mg KT that achieved the desired balance of excellent elasticity and low water content. Moreover, a successful retardation of KT release rate was achieved (82%) after 48 h with favored initial fast drug release in the first hour (32.7%) to attain rapid analgesic effect. The clinical assessments in arthritic rats revealed apparent improvement in joint space narrowing, highest increase in bone mineral density at the proximal tibia and distal femur joints with the absence of osteophytosis only in animal group treated with combined HA-KT membrane. Application of K8 membrane was able to preserve KT plasma concentration above its minimum effective concentration for 48 h therefore, would able to replace six commercial tablets each of 10 mg KT.

ROS production and their influence on the cellular antioxidative system in human erythrocytes incubated with daunorubicin and glutaraldehyde.

This study examined the effects of daunorubicin and glutaraldehyde on some parameters of erythrocytes. The aim of the article was to present the results of research aiming to identify the level of glutaraldehyde at which the hemoglobin oxidation, externalization of phosphatidylserine and the changes in the viability (hemolysis) of erythrocytes are not statistically significant and therefore this level of glutaraldehyde can be used for the drug carriers' preparation. Glutaraldehyde was used as a crosslinking agent to enhance the uptake of the drug within red blood cells and to prevent its leakage from the cells. Fluorescence microscopy, flow cytometry and fluorimetric measurements confirmed higher levels of the drug in glutaraldehyde-treated human erythrocytes. Unfortunately, substantial damage to the red blood cells was also noted. DNR increased oxidative processes in the cell, which in turn led to an increase in the reactive oxygen species (ROS) level. When the red blood cells were also treated with glutaraldehyde, ROS production was significantly higher. We also observed loss of both the reduced and the total glutathione. Moreover the decreased activity of glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD) was also observed. As hemoglobin, the erythrocytes' main component plays an essential role in the erythrocytes, the level of its oxidized form (metHb) in the erythrocytes and the phosphatidylserine exposure on the erythrocyte surface were also investigated. When higher concentrations of glutaraldehyde (0.0025-0.005%) were used for the uptake of DNR the elevated level of metHb was observed. Only at 0.0005% the level of oxidized form of Hb was within the physiological level and at that level the increase in the exposure of phosphatidylserine at the cell surface was not observed to be statistically significant. Moreover the percent of released hemoglobin was less than 1%. Based on these results it was concluded that glutaraldehyde can be used as a cross-linker between the drug (DNR) and the erythrocytes only at low concentration of about 0.0005%.

Effects of glutaraldehyde concentration, pretreatment time, and type of tissue (porcine versus bovine) on postimplantation calcification.

OBJECTIVE: Our objective was to evaluate the effects of glutaraldehyde (GA) concentration, time of pretreatment, and type of tissue (porcine vs bovine) on quantitative and qualitative postimplant calcification of tissues. METHODS: Freshly obtained porcine and bovine pericardial tissues were each treated with increasing concentrations of GA (controls, 0.3125%, 0.625%, and 1.2%) for a fixed time (15 minutes) or increasing exposure times (5, 10, 20, and 30 minutes) at a fixed concentration of GA (0.625%). Pretreated tissues were subcutaneously implanted in 10-week-old Sprague-Dawley rats for 45 days before explantation. Quantitative calcium analysis was performed by flame atomic spectrophotometry. Histologic examination of tissue samples with hematoxylin and eosin and von Kossa staining was performed for cellular and inflammatory response, autolysis, and calcification. RESULTS: Two-way analysis of variance indicated significantly greater calcium levels at 1.2% compared with each lower concentration for both porcine and bovine samples (P < .01). Significantly lower calcium levels were detected with increased exposure time in porcine samples (F = 6.97; P < .001); however, no significant differences in calcium levels were observed between different exposure times for bovine samples (F = 1.46; P = .23). Histologic evidence of inflammatory response with infiltration with mononuclear cells, fibroblasts, and histiocytes was seen in all grafts; however, it varied from mild to severe without any pattern. There were no differences in degree or pattern of inflammatory response according to GA concentration or time of exposure. Estimation of amount of calcification by histologic examination correlated with the quantitative assay. CONCLUSIONS: Increasing GA concentration leads to greater calcification with a sharp rise in calcium levels above a concentration of 0.625%, in both bovine and porcine pericardial tissues. At a concentration of 0.625%, increasing pretreatment time is inversely related to tissue calcification for porcine pericardium but not for bovine pericardium. Differences in the tissue composition in terms of cellular content and composition of the extracellular matrix could account for the observed findings.

Comparison of two different forms of varnishes in the treatment of dentine hypersensitivity: a subject-blind randomised clinical study.

PURPOSE: Dentine hypersensitivity is one of the most frequently recorded complaints of dental discomfort. Current evidence implicates patent dentinal tubules in hypersensitive dentine, and it follows that one effective way to reduce dentine sensitivity is to occlude the dentinal tubules. The purpose of this study was to compare the efficacy of two different desensitising agents, Cervitec varnish and Gluma varnish. MATERIALS AND METHODS: Two hundred fifty patients self-reporting dentine hypersensitivity completed the paired split mouth randomised, subject-blind study. Each participant had a minimum of two sensitive teeth in at least two different quadrants and displaying a response of ≥3 cm to an evaporative stimulus. The hypersensitivity levels were measured with a tactile stimulus (scratchometer), thermal stimulus (cold water test), and an evaporative stimulus (air blast test) using a visual analogue scale. The teeth were evaluated immediately after treatment, and at 4 and 12 weeks after application of the chlorhexidine-containing varnish Cervitec and the glutaraldehyde-containing varnish, Gluma Desensitizer. RESULTS: Statistical analysis indicated that both the desensitising varnishes were effective in alleviating dentine hypersensitivity at all time intervals compared to baseline. There was a highly statistically significantly greater reduction in dentine hypersensitivity to evaporative stimulus, cold stimulus, and tactile stimulus after application of Cervitec than after Gluma Desensitizer (P < 0.001). CONCLUSION: Both the varnishes have a therapeutic potential to alleviate dentine hypersensitivity at all time intervals compared to baseline. However, Cervitec varnish is more efficacious in reducing dentine hypersensitivity than Gluma varnish at both 4 weeks and 12 weeks post-treatment.

Efficacy of various spray disinfectants on irreversible hydrocolloid impression materials: an in vitro study.

BACKGROUND: Most of the materials (casts, impressions, etc.) that are sent to the dental laboratories show the presence of numerous pathogenic microorganisms. All the spray disinfectants are not equally effective against these microorganisms. AIMS AND OBJECTIVES: The aim was to compare the effectiveness of different spray disinfectants on irreversible hydrocolloid impressions and to find out the most effective dilution, contact time, and effect against each microorganism studied. MATERIALS AND METHODS: The effects of four spray disinfectants, 5.25% sodium hypochlorite, 0.525% sodium hypochlorite, 1:213 (1 part in 213 parts of water) povidone iodine, and 2% glutaraldehyde along with control (distilled water) on irreversible hydrocolloid impressions contaminated with Staphylococcus aureus, Bacillus subtilis and Streptococcus viridans were studied. RESULTS: Sodium hypochlorite, 5.25%, showed 1-min exposure time which was able to effect a 4 log 10 reduction in bacterial counts against S. aureus and S. viridans followed by 0.525% sodium hypochlorite and 2% glutaraldehyde for 10 min. None were able to effect a 4 log10 reduction against B. subtilis. CONCLUSION: Sodium hypochlorite with a concentration of 5.25% was the most effective disinfectant and required the shortest contact time (1 min). Not all ADA-approved concentrations of surface disinfectants work equally well on irreversible hydrocolloid impression materials.