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PubMedDate not supplied

Modification of a vinyl glove into a dental dam for patients sensitive to latex rubber.

Dental products containing latex rubber such as rubber dams, gloves, polishing points, prophy cups, blood pressure cuffs, orthodontic elastics, mouth props, intubation tubes, and anesthetic masks have the potential to cause allergic reactions. The clinician should try to identify patients at high risk for latex sensitivity by taking a careful history and, where necessary, using alternative products. This paper describes how a vinyl glove can be easily modified to provide an effective dental dam in patients allergic to latex rubber.

Dental Restoration, Permanent↗
PubMedDate not supplied

Rubber dam isolation of cervical lesions. Part 1: Alternative techniques which avoid injury to the periodontium.

While it is arguable that the operative procedures depicted in this article could have been done equally well with alternative forms of isolation, it is indisputable that rubber dam provides for the most thorough 'isolation' in the comprehensive sense of the term. It allows for the finite control over peripheral variables such as access and controlled gingival retraction. This in turn permits meticulous execution of restorative procedures within the luxury of 'true four-handed dentistry'. Most operative procedures are done within the limitations of single handed dentistry as the other 'three hands' are involved with retraction, fluid evacuation and access control. The rubber dam is indeed indispensable and with the increased awareness of infection control it is conceivable that rubber dam isolation will continue to be associated with quality patient care. Part 2 of this article will detail the application of the 'Modified Gingival Retractor' in the isolation of cervical lesions.

Constriction↗
PubMed1998

Sickness absence in a rubber plant in Poland.

The disease-related temporary incapacity for work, its causes and duration are essential factors in the assessment of health status of the occupationally active population. The aim of the present study was to investigate the main causes of work disability among the rubber industry workers, with special regard to sickness absence among workers directly enganged in manufacture. The study was performed in 1995 on a sample of 973 workers (456 males and 517 females) at a plant producing rubber footware. The number of days of work disability from a particular disease, frequency and duration per year were examined. The analysis concerned such parameters of sickness absence as the lost time rate, average duration of absence, and percentage of workers on a sick-leave. The results revealed that during the period under study the main medical causes of the sickness absence included: a) for males--cardiovascular diseases (48% of the total sickness absence), respiratory diseases (18%), gastrointestinal disease (8%) and the nervous system and sense organs diseases (8%); b) for females--cardiovascular diseases (24%), respiratory diseases (16%), pregnancy, childbirth and puerperium complications (11%) and neoplasms (10%). The sickness absence of workers directly involved in the manufacture appeared to be by 72% higher than that noted for workers of other departments, with the age- and gender-standardized lost time rate of 4.74. The differences can be related mainly to a higher percentage of the sick in the group of 'production workers' (43%) as compared to the 'non-production' ones (28%). The findings of our study indicate that in the rubber industry workers a high rate of absence due to some groups of diseases may be associated with exposure to hazardous agents in their work environment.

Absenteeism↗
PubMedDate not supplied

[Sensitivity to latex and other rubber substances--an important occupational risk for health personnel (case report)].

Sensitization to latex and rubber additives has been acknowledged during the last 10 years as a major occupational health problem among health-care workers. In sensitized persons, respiratory and/or skin symptoms may be present. Pathophysiologic mechanisms of senzitisation involve allergic reactions types I and IV (Coombs and Gell). In this case report we described a female health-care worker with sensitization to latex and rubber additives simultaneously present on the skin and in the respiratory system, caused by wearing protective rubber gloves. The complex diagnostic procedure involved in determination of occupational allergic diseases is discussed.

Adult↗
PubMed2000

In vitro formation of oropharyngeal biofilms on silicone rubber treated with a palladium/tin salt mixture.

Adhesion of yeasts and bacteria to silicone rubber is one of the first steps in the biodeterioration of indwelling, silicone rubber voice prostheses. In this paper, silicone rubber, so-called "Groningen button," voice prostheses were treated with a colloidal palladium/tin solution to form a thin metal coat intended to discourage biofilm formation. First it was demonstrated that this treatment did not negatively affect the airflow resistance of the prostheses or induce any cytotoxicity. Subsequently, palladium/tin-treated voice prostheses were placed in a modified Robbins device together with untreated control prostheses to evaluate biofilm formation. Biofilms were formed by inoculating the device for 3 days with the total cultivable microflora obtained from an explanted, malfunctioning voice prosthesis supplemented with separately isolated yeasts (Candida albicans and Candida tropicalis). After 3 days the device was perfused three times daily with growth medium and phosphate-buffered saline. The device was allowed to drain between perfusions to better mimic the conditions in the oropharynx (moist but not always fully wetted). After 9 days the total number of bacterial and fungal colony-forming units on the prostheses were determined microbiologically, and scanning electron micrographs were taken of the valve sides. Biofilm formation was significantly less on the heavily treated palladium/tin prostheses than it was on the untreated prostheses although some ingrowing microcolonies also were observed on the treated prostheses. The spread of the biofilms was smaller on the treated prostheses than on the untreated ones.

Bacterial Adhesion↗
PubMed2005

Rubber band ligation versus excisional haemorrhoidectomy for haemorrhoids.

BACKGROUND: Traditional treatment methods for haemorrhoids fall into two broad groups: less invasive techniques including rubber band ligation (RBL), which tend to produce minimal pain, and the more radical techniques like excisional haemorrhoidectomy (EH), which are inherently more painful. For decades, innovations in the field of haemorrhoidal treatment have centred on modifying the traditional methods to achieve a minimally invasive, less painful procedure and yet with a more sustainable result. The availability of newer techniques has reopened debate on the roles of traditional treatment options for haemorrhoids. OBJECTIVES: To review the efficacy and safety of the two most popular conventional methods of haemorrhoidal treatment, rubber band ligation and excisional haemorrhoidectomy. SEARCH STRATEGY: We searched all the major electronic databases (MEDLINE, EMBASE, CENTRAL, CINAHL). SELECTION CRITERIA: Randomised controlled trials comparing rubber band ligation with excisional haemorrhoidectomy for symptomatic haemorrhoids in adult human patients were included. DATA COLLECTION AND ANALYSIS: We extracted data on to previously designed data extraction sheet. Dichtomous data were presented as relative risk and 95% confidence intervals, and continuous outcomes as weighted mean difference and 95% confidence intervals. MAIN RESULTS: Three trials (of poor methodological quality) met the inclusion criteria. Complete remission of haemorrhoidal symptom was better with EH (three studies, 202 patients, RR 1.68, 95% CI 1.00 to 2.83). There was significant heterogeneity between the studies (I2 = 90.5%; P = 0.0001). Similar analysis based on the grading of haemorrhoids revealed the superiority of EH over RBL for grade III haemorrhoids (prolapse that needs manual reduction) (two trials, 116 patients, RR 1.23, CI 1.04 to 1.45; P = 0.01). However, no significant difference was noticed in grade II haemorrhoids (prolapse that reduces spontaneously on cessation of straining) (one trial, 32 patients, RR 1.07, CI 0.94 to 1.21; P = 0.32) Fewer patients required re-treatment after EH (three trials, RR 0.20 CI 0.09 to 0.40; P < 0.00001). Patients undergoing EH were at significantly higher risk of postoperative pain (three trials, fixed effect; 212 patients, RR 1.94, 95% CI 1.62 to 2.33, P < 0.00001). The overall delayed complication rate showed significant difference (P = 0.03) (three trials, 204 patients, RR 6.32, CI 1.15 to 34.89) between the two interventions. AUTHORS' CONCLUSIONS: The present systematic review confirms the long-term efficacy of EH, at least for grade III haemorrhoids, compared to the less invasive technique of RBL but at the expense of increased pain, higher complications and more time off work. However, despite these disadvantages of EH, patient satisfaction and patient's acceptance of the treatment modalities seems to be similar following both the techniques implying patient's preference for complete long-term cure of symptoms and possibly less concern for minor complications. So, RBL can be adopted as the choice of treatment for grade II haemorrhoids with similar results but with out the side effects of EH while reserving EH for grade III haemorrhoids or recurrence after RBL. More robust study is required to make definitive conclusions.

Hemorrhoids↗
PubMed2001

A [2]catenane and a [2]rotaxane as prototypes of topological and Euclidean molecular "rubber gloves".

A [2]catenane and a [2]rotaxane have been prepared from a C2-symmetric, 2,9-diphenyl-1,10-phenanthroline-based (dpp-based) macrocycle incorporating a 1,5-dioxynaphthalene subunit by means of the transition metal templated technique. In the case of the catenane, this macrocycle is interlocked with a dpp-based macrocycle that is oriented through the location of a p-tolyl substituent in the 4-position of the phenanthroline subunit. In the case of the rotaxane, the C2-symmetric macrocycle is threaded onto an oriented, dumbbell-shaped molecule, based on the same 4-p-tolyl-1,10-phenanthroline subunit, which bears tetraarylmethane stoppers. Both species are chemically achiral molecules, yet they are composed entirely of asymmetric, mirror-image conformations. Conformational enantiomerization processes therefore take place exclusively by chiral pathways, conferring on these molecules the "rubber glove" property. However, while the molecular graph (constitutional formula) of the [2]rotaxane can be deformed into a planar and, hence, rigidly achiral representation, a feature shared by a few other compounds in the literature that have been characterized as "Euclidean rubber gloves", the molecular graph of the [2]catenane cannot be deformed in this way. It therefore has the unique property of being a chemically achiral "topological rubber glove".

Journal Article↗
PubMed1982

Reduced catheter sepsis and prolonged catheter life using a tunnelled silicone rubber catheter for total parenteral nutrition.

One hundred and five patients were given total parenteral nutrition (TPN) for an average of 15 days via centrally placed venous catheters. Thirty-seven polyvinyl chloride (PVC) and 80 silicone rubber catheters were used. All the silicone rubber and 8 of the PVC catheters were buried in a subcutaneous tunnel. When silicone rubber catheters were used, there was significantly less catheter sepsis (P much less than 0.01), catheter life was prolonged by 50 per cent and fewer catheter insertions per patient were necessary.

Catheterization↗
PubMed2002

Surface modification of an experimental silicone rubber aimed at reducing initial candidal adhesion.

Silicone rubber, which is a widely used biomaterial, is often used to make soft liners for permanent denture. Colonization of denture soft lining materials by Candida albicans can result in clinical problems. The aim of this study was to chemically modify the surface of an experimental silicone rubber in order to produce a silicone that was less susceptible to candidal colonization. Surface modification was carried out with the use of argon-plasma bombardment followed by silane treatment, which caused the incorporation of either hydrophilic or hydrophobic functional groups onto the surface. Changes in water contact angles and chemical analysis of the materials with scanning ion mass spectroscopy confirmed surface changes. In vitro assays were carried out using C. albicans to measure levels of adherence to the surface-modified silicone after 1 h. C. albicans exhibited very low adherence to all silane-treated surfaces, whether hydrophobic or hydrophilic. This led to the conclusion that incorporated long-chain functional groups were inhibiting the adherence of the yeast, possibly by the formation of a barrier between the surface of the material and the yeast. In conclusion, silane surface treatment of an experimental silicone rubber has been successful in reducing candidal adherence.

Biocompatible Materials↗
PubMed2001

Air-flow resistances of silicone rubber voice prostheses after formation of bacterial and fungal biofilms.

Laryngectomized patients use silicone rubber voice prostheses to rehabilitate their voice. However, biofilm formation limits the lifetime of voice prostheses by causing leakage or an increased air-flow resistance and the prosthesis has to be replaced. To determine which bacterial or yeast strains, isolated from explanted voice prostheses, contribute most to increases in air-flow resistance of silicone rubber voice prostheses, biofilms consisting of either a bacterial or a yeast strain were grown on voice prostheses in the artificial throat model. The effects of these biofilms on air-flow resistances were determined by calculating the difference in air-flow resistance of the individual voice prosthesis as covered with a 7-day-old biofilm with the situation prior to biofilm formation. Conspicuously, voice prosthetic biofilms formed by the bacterial strains Staphylococcus aureus GB 2/1 and Rothia dentocariosa GBJ 41/25B and their excreted organic matter showed larger increases in air-flow resistance (more then 30 cm H(2)O.s/L) than biofilms formed by Candida species. This is contrary to the literature, where there seems to be agreement that Candida species are mainly responsible for clinical failure of silicone rubber voice prostheses.

Bacteria↗
PubMed1976

In vivo degradation of silicone rubber poppets in prosthetic heart valves.

Dynamic shear modulus G' was measured throughout the volume of three nonvariant silicone rubber poppets which were recovered from aortic prosthetic heart valves that had been implanted for 4 days, 52 days, and 8 years. Similar measurements were obtained for two unused silicone rubber poppets. Although the recovered poppets exhibited no obvious physical evidence of damage, the silicone rubber had undergone in vivo degradation throughout the poppet volume as indicated by decreases in modulus. The measurements also indicate that the poppet surface degrades at a rate faster than the core. Further, comparison with data reported in the literature suggests that the surfaces of variant poppets degrade at a rate faster than the surfaces of nonvariant poppets.

Aortic Valve↗
PubMed1982

Ex vivo shunt testing of hydrogel-silicone rubber composite materials.

Hydrogel polymers consisting of HEMA (2-hydroxyethyl methacrylate) alone or co-polymerized with NVP N-(vinyl pyrrolidone) were incorporated into silicone rubber tubing to produce hydrophilic composite materials. Polymerization methods of the interpenetrating network (IPN) and radiation-induced type were used to impregnate the silicone rubber substrates. These methods produced materials with varied wettability (contact angle with water ranged from 57 degrees to 95 degrees) but similar texture. The surface morphology as observed in the scanning electron microscope was the same for all the materials. Four types of composite materials and two sizes of silicone rubber control tubing in a total of 19 dogs were used as ex vivo femoral artery-to-vein (A-V) shunts and were sampled at 5, 15, 30, 45, and 60 min. Data obtained by using scanning electron microscopy (SEM) were used to determine the type and amount of adhering blood cells at the time intervals described. Large platelet aggregates and/or a variable initial response were found to be predictors of shunt failure (occlusion). Most samples showed only varied levels of platelet adhesion, but other cell types were seen in some samples. The adhesion was found to peak in all cases by 30 min and to reach lower levels by 60 min, suggesting that an initial phase of reaction was complete. The course of platelet adhesion for a 60-min period is presented.

Animals↗
PubMed1988

Silicone rubber temporomandibular joint (TMJ) meniscal replacements: postimplant histopathologic and material evaluation.

Medical grade silicone rubber has long been considered a suitable meniscal replacement, but there has been increasing concern about migration of this material into adjacent tissues. The objectives of this study were to determine the definitive composition of tissue-incorporated material which is presumed by light microscopy to be silicone and to identify long term histopathologic sequelae of meniscal replacements. Adult female patients underwent meniscectomy and replacement with silicone rubber (Silastic) implants. After 12 to 18 months, recurrence of symptoms in 8% of these cases led to implant removal with excision of peri-implant fibrous pseudocapsules. Excised tissues, including one preauricular lymph node and implants were submitted for light microscopy, SEM, and energy dispersive x-ray microanalysis (EDX) for the identification of elemental composition, critical surface tension measurement, and internal reflection infrared spectroscopy. EDX revealed prominent peaks for silicon in both pseudocapsular and nodal tissues. Morphologic findings surrounding the long-term implants included foreign body reaction, synovitis, dystrophic calcification, fibrocartilaginous metaplasia, hyalinization, and scarring. Particulate silicone debris induced a pathologic response in the tissues and migrated to nodes. These findings suggest that periodic evaluation be performed over the life of such implants to rule out breakdown under function. These findings should intensify the search for improvements or replacements for silicone rubber as an interpositional material in the temporomandibular joint.

Calcinosis↗
PubMed1991

Improved biocompatibility of silicone rubber by removal of surface entrapped air nuclei.

Biomaterials activate the complement system which is important since C3a promotes platelet aggregation and release, and C5a activates neutrophils that may augment coagulation. Tiny air nuclei (microbubbles) are found in the surface roughness of biomaterials on exposure to a liquid, therefore two interfaces exist: (a) a blood/biomaterial, and (b) a blood/air interface. Experiments were carried out that documented that air bubbles activate complement and augment in vitro platelet aggregation in human plasma. The air nuclei were removed from the surface of silicone rubber by a technique termed denucleation to determine if complement activation and platelet aggregation could be reduced. We observed a significant reduction in C3a and C5a in the plasma samples incubated with denucleated silicone rubber as compared to the control samples (p less than 0.001, ANOVA). The plasma incubated with the denucleated silicone caused reduced platelet aggregation as compared to the plasma incubated with the control silicone when added to a platelet suspension (p less than 0.001, ANOVA). Surface chemical analysis by x-ray photo-electron spectroscopy (XPS) showed no change in the silicone rubber surface after the denucleation procedure.

Air↗
PubMed1991

Effect of silicone rubber surface on the calcium balance of human serum.

The nature and mechanism of calcium complexation with human serum components in the presence of silicone rubber were assessed in in vitro model experiments. Silicone rubber samples were incubated for 67 h in serum of both physiologic calcium concentrations and induced hypercalcemic levels. Physiologic calcium incubation decreased the intrinsic and nth binding site association constants by factors of 2 and 4, respectively, from initial serum values. Incubation with silicone rubber did not change the association constants. Hypercalcemia incubation lowered the intrinsic and nth binding site association constants by 39 and 61%, respectively. Polymer incubation increased the intrinsic association constant and decreased the number of binding sites by a factor of 2. With initial binding site association constants unperturbed by incubation and Hill coefficients equivalent to 1, complexation was non-cooperative and binding sites were considered to be identical and independent. Both Scatchard and Hill plots show nonlinearity for the polymer incubation case giving two distinct linear regions. This is indicative of cooperative binding for incubation with polymer; the Hill coefficient for the physiologic calcium concentration range was 0.97, while the coefficient for the hypercalcemic calcium range was 6.

Calcium↗
PubMed2000

Micronized purified flavonidic fraction compared favorably with rubber band ligation and fiber alone in the management of bleeding hemorrhoids: randomized controlled trial.

PURPOSE: The aim of this study was to assess the role of micronized purified flavonidic fraction in the management of bleeding nonprolapsed hemorrhoids. METHODS: Patients were randomly assigned to receive ispaghula husk alone, rubber band ligation plus ispaghula husk, or micronized purified flavonidic fraction plus ispaghula husk. Other colorectal diseases were excluded by colonoscopy. Blinded observers noted the time for bleeding to stop completely, recurrences, and treatment complications. RESULTS: A total of 162 patients were randomly assigned with no significant differences in the age and gender distributions among the groups. Hemorrhoidal bleeding was relieved most expediently in the micronized purified flavonidic fraction plus ispaghula husk group (ispaghula husk alone n = 66, mean (standard error of the mean) 10.6 (2.3) days; rubber band ligation plus ispaghula husk n = 57, 5.6 (1.1) days; micronized purified flavonidic fraction plus ispaghula husk n = 39, 3.9 (1.2) days; P = 0.03). However, there were no significant differences in the recurrences at six months of follow-up (ispaghula husk alone n = 8 (12 percent); rubber band ligation plus ispaghula husk n = 12 (21 percent); micronized purified flavonidic fraction plus ispaghula husk n = 2 (5.1 percent); P = 0.075). No complications or side-effects were noted. CONCLUSIONS: micronized purified flavonidic fraction used with fiber supplements rapidly and safely relieved bleeding from nonprolapsed hemorrhoids.

Adult↗
PubMed1998

The effect of buttermilk consumption on biofilm formation on silicone rubber voice prostheses in an artificial throat.

Biofilm formation on indwelling silicone rubber voice prostheses in laryngectomized patients is still the main reason for dysfunction of the valve, leading to frequent replacements. Within patient support groups in The Netherlands, laryngectomees have suggested that the consumption of buttermilk prolongs the life-time of indwelling silicone rubber voice prostheses. The aim of the present study was to compare biofilm formation on Groningen button voice prostheses in a so-called artificial throat. Ten prostheses were placed in a simulated control group and ten other prostheses in a group with a simulated consumption of 700 ml buttermilk three times a day. Biofilms were allowed to grow on the prostheses by inoculating two artificial throats with the total cultivable microflora (bacteria and yeasts) isolated from an explanted Groningen button voice prosthesis. After 3 days, one artificial throat was perfused three times daily with phosphate buffer (control group) for 8 days, while the other artificial throat was perfused with buttermilk. Prostheses removed from the artificial throat in the control group were covered with a thick biofilm. Scanning electron microscopy showed microcolonies growing into the silicone rubber, similar to the ingrowth observed on explanted Groningen buttons. The simulated consumption of buttermilk in the other artificial throat almost fully prevented the formation of a biofilm on the prostheses during the experimental period. These in vitro experiments in the artificial throat demonstrate that the deterioration of voice prostheses can be lessened by the daily intake of buttermilk through its inhibitory effects on biofilm formation.

Animals↗
PubMed2006

Effect of air humidity on the egg viability of predatory mites (Acari: Phytoseiidae, Stigmaeidae) common on rubber trees in Brazil.

Rubber pest mites, Calacarus heveae and Tenuipalpus heveae, reach economic damage levels at the end of the rainy season and the beginning of the dry season in Brazil. Therefore, low humidity adaptation might be an important characteristic for predatory mites to successfully control pest organisms. This study determined the effect of the relative humidity (RH) levels of 30-100% on the hatching of larvae of Amblyseius acalyphus, Euseius citrifolius, Iphiseiodes zuluagai, Metaseiulus camelliae, Agistemus floridanus and Zetzellia malvinae at 25 +/- 0.5 degrees C. These predatory mites are common on rubber trees in the state of São Paulo and might be used for introduction in the major rubber tree production regions in the state of Mato Grosso. At 70% RH or higher, viability was 70% or higher for all species, indicating that their performance might be higher during the rainy season than during the dry season. Eggs of E. citrifolius and M. camelliae presented higher viability at the lower relative humidity levels than those of other species, indicating that these species might have higher chance to persist in the dry season. It is suggested that M. camelliae should be further evaluated for introduction in the state of Mato Grosso, considering that this mite is not yet present in that area.

Animals↗