Effect Of Blood Contamination Research Articles

Effect of blood contamination on bond strength of different root‑end filling materials to dentin

Amaç: Bu in vitro çalışmanın amacı, kan kontaminasyonunun farklı kök ucu dolgu materyallerinin dentine bağlanma dayanımına etkisinin değerlendirilmesiydi. Gereç ve Yöntem: Bu çalışmada tek köklü 90 adet maksiler santral diş kullanıldı. Dişlere endodontik tedavi uygulandıktan sonra kök uçları rezeke edildi ve kök ucu kaviteleri hazırlandı. Öncelikle örnekler, kavitelerin kanla kontaminasyonuna göre (+/-) 2 gruba ayrıldı. Daha sonra kök ucu dolgu malzemelerine göre üç alt gruba ayrıldı: MTA Repair HP, RetroMTA, MTA Flow (n=15). Bu malzemeler üreticinin talimatları doğrultusunda kaviteye yerleştirildi. Örnekler 21 gün boyunca 37 °C’de %100 nemli ortamda bekletildi. 1.0±0.1 mm kesitler elde edildikten sonra itme-bağlanma dayanımı testi gerçekleştirildi. Başarısızlık tipini değerlendirmek için her kesit stereomikroskop altında incelendi. Veriler tek yönlü varyans analizi ve bağımsız örneklem t-testi kullanılarak analiz edildi. Bulgular: Bağlanma dayanımı, kan kontaminasyonunun varlığından önemli ölçüde olumsuz yönde etkilendi (p<0.05). En yüksek bağlanma dayanımı MTA Flow (-) grubunda, en düşük bağlanma dayanımı ise MTA Repair HP (+) grubunda gözlendi (p<0.05). Hem kanla kontamine olan grupta hem de kanla kontamine olmayan grupta MTA Repair HP en düşük bağlanma dayanımını gösterirken (p<0.001), MTA Flow ve RetroMTA arasında anlamlı farklılık bulunmadı (p>0.05). Sonuç: Kan kontaminasyonu dentine bağlanma dayanımını azalttı. Materyaller arasında en yüksek bağlanma dayanımını MTA Flow gösterdi.

Push-out bond strength of the calcium silicate-based endodontic cements in the presence of blood: A systematic review and meta-analysis of in vitro studies.

ObjectivesThe push‐out bond strength (POBS) of calcium silicate‐based cements (CSCs) to the dentinal wall is considered one of the essential physical properties for clinical success. The presence of blood in the treatment area affects the POBS of these types of cement. This study aimed to evaluate the impact of blood contamination on the bond strength of CSCs and dentinal walls.Material and MethodsThis systematic review was performed by searching electronic databases (MEDLINE‐PubMed, Scopus, and EMBASE) to include relevant in vitro studies published between 1992 and April 2020. Two reviewers independently evaluated the selected studies and extracted data on the type of studied CSCs, evaluated area of the teeth, sample size, the dimension of a prepared area, slice thickness, storage duration, the setting of the universal testing machine (UTM), effects of blood contamination on POBS of CSCs and their failure modes. The bond strength of evaluated CSCs in studies was used for network meta‐analysis.ResultsInitial searches identified 292 articles, while only 13 articles met the inclusion criteria. Full texts of these articles were evaluated, and data extraction was performed. The effect of blood contamination on bond strength to the dentinal wall was assessed in various CSCs such as PMTA, Biodentine, and AMTA. The network meta‐analysis results showed that the bond strength of Biodentine was significantly higher than other types of cement in blood presence (p < .05).ConclusionsBased on the current systematic review, despite controversies among the result of the different articles and the lack of data for some CSCs like bioaggregate, it could be concluded that the bond strength of Biodentine to the dentinal wall is better than other evaluated CSCs in the presence of blood.

THE EFFECT OF BLOOD CONTAMINATION ON SHEAR BOND STRENGTH OF CALCIUM SILICATE-BASED PULP CAPPING MATERIALS

Objectives: The aim of this study was to examine the effect of different hardening times and blood contamination of MTA and Biodentine, which are widely used for pulp capping treatments in the market, on shear bond strength (SBS) with a self-etch adhesive resin, after different hardening times (24, 48, 72 and 96 hours). Materials and Methods: Slots with a diameter of 5 mm and a height of 2 mm were prepared in 192 acrylic blocks for this study. Both ProRoot MTA and Biodentine were prepared according to the manufacturer’s instructions, and half of the slots were filled with ProRoot MTA and the other half were filled with Biodentine. All the samples were divided into groups depending on four different hardening times and hardened. After hardening process completed, the group of each hardening time was divided into 2 subgroups (n:12) with and without contamination. In the uncontaminated groups, a self-etch adhesive resin (Clearfil Liner Bond) and a resin-based composite (Filtek P60) were applied on the samples and polymerized. In the contaminated groups, the sample surfaces were contaminated with blood for 20 seconds. After washing and drying the samples, adhesive resin and composite were applied on them. After that SBS tests were performed and the data were subjected to a 2-way ANOVA test analysis. Results: In the uncontaminated groups, there was no significant difference in the SBS of each pulp capping material depending on different hardening times (p&amp;gt;0.05). ProRoot MTA showed statistically higher SBS than Biodentine in the 72 and 96 hour uncontaminated groups (p&amp;lt;0.05). Blood contamination caused a significant decrease in the SBS of ProRoot MTA and Biodentine (p&amp;lt;0.05). Conclusions: In this study, it was determined that blood contamination reduces the SBS of pulp capping materials. Therefore, it is recommended to prolong the hardening times of the capping materials and to take clinical measures to prevent blood contamination as much as possible before restorative treatments are performed.

Effect of blood contamination and various hemostatic procedures on the push-out bond strength of Biodentine when used for furcation perforation repair.

Background:Perforations in the furcation area are common procedural accidents that can impact the outcome of treatment. There are many bioactive materials available to repair these defects.Aim:The purpose of this study was to determine and compare the effect of 25% aluminum chloride solution, 20% ferric sulfate solution, and a 980-nm diode laser, when used for hemostasis, on the dislocation resistance of Biodentine placed to repair furcation perforation.Materials and Methods:This in vitro study was conducted on fifty extracted human permanent mandibular molars, with ten teeth in each group. The stimulated perforations were contaminated with blood, except for one group. The contaminated groups were either treated with aluminum chloride, ferric sulfate, diode laser, or none at all. All the perforations were restored with Biodentine and tested for push-out bond strength.Statistical Analysis Used:One-way analysis of variance and Tukey's HSD post hoc test were applied with a level of significance set at 0.05.Results:The dislocation resistance of Biodentine was found to be highest when aluminum chloride or diode laser was used for arresting bleeding. In contrast, the ferric sulfate group gave the lowest value for push-out bond strength (P < 0.05).Conclusions:According to the present study, the use of ferric sulfate as a hemostatic agent showed a negative effect on the bond strength of the calcium silicate cement to dentin. Furthermore, Biodentine performed better when diode laser and aluminum chloride were used for hemostasis.

Effect of Blood Contamination on Marginal Adaptation of MTA and Endosequence Root Repair Material as a Retrograde Filling

Purpose: This study was designed to compare marginal adaptation of MTA and Endosequence Root Repair Material (ERRM) as retrograde filling materials. Materials and methods: 40 maxillary anterior teeth were prepared and obturated with gutta-percha and AH plus using lateral compaction technique. Apical 3mm of the roots were resected and retrograde cavities were prepared with diamond coated ultrasonic retrotip. Teeth were divided randomly into two main groups (I,II) according to blood contamination of retrograde cavities and every group then divided into two sub-groups (A,B) according to retrograde materials (MTA,ERRM). Teeth sectioned longitudinally and examined for marginal gap using SEM. Results: revealed that the high mean value in cavities without blood contamination and filled with MTA in group I and the high mean value in cavities smeed with blood contamination and filled with MTA in group II. There was no statistically significant difference between 4 groups. Conclusion: MTA and ERRM exhibited nearly comparable marginal adaptation in dry or blood environment.

Towards a unified protocol for handling of CSF before \u03b2-amyloid measurements

BackgroundWidespread implementation of Alzheimer’s disease biomarkers in routine clinical practice requires the establishment of standard operating procedures for pre-analytical handling of cerebrospinal fluid (CSF).MethodsHere, CSF collection and storage protocols were optimized for measurements of β-amyloid (Aβ). We investigated the effects of (1) storage temperature, (2) storage time, (3) centrifugation, (4) sample mixing, (5) blood contamination, and (6) collection gradient on CSF levels of Aβ. For each study participant, we used fresh CSF directly collected into a protein low binding (LoB) tube that was analyzed within hours after lumbar puncture (LP) as standard of truth. Aβ42 and Aβ40 were measured in de-identified CSF samples using EUROIMMUN and Mesoscale discovery assays.ResultsCSF Aβ42 and Aβ40 were stable for at least 72 h at room temperature (RT), 1 week at 4 °C, and 2 weeks at − 20 °C and − 80 °C. Centrifugation of non-blood-contaminated CSF or mixing of samples before the analysis did not affect Aβ levels. Addition of 0.1–10% blood to CSF that was stored at RT without centrifugation led to a dose- and time-dependent decrease in Aβ42 and Aβ40, while Aβ42/Aβ40 did not change. The effects of blood contamination were mitigated by centrifugation and/or storage at 4 °C or − 20 °C. Aβ levels did not differ between the first to fourth 5-ml portions of CSF.ConclusionsCSF can be stored for up to 72 h at RT, 1 week at 4 °C, or at least 2 weeks at either − 20 °C or − 80 °C before Aβ measurements. Centrifugation of fresh non-blood-contaminated CSF after LP, or mixing before analysis, is not required. In case of visible blood contamination, centrifugation and storage at 4 °C or − 20 °C is recommended. After discarding the first 2 ml, any portion of up to 20 ml of CSF is suitable for Aβ analysis. These findings will be important for the development of a clinical routine protocol for pre-analytical handling of CSF.

Effect of blood contamination on amniotic fluid detection in vitro using immunoassays

Objective: To determine the accuracy of Actim PROM®, Amnisure®, and ROM Plus® tests for detecting amniotic fluid proteins in the setting of blood contamination.Methods: IGFBP-1 and AFP are proteins present in high concentrations in amniotic fluid, and are detected by three commercially-available immunoassays used for diagnosing ruptured membranes: Actim PROM®, Amnisure®, and ROM Plus®. We used whole blood samples and diluted these with amniotic fluid (containing known concentrations of amniotic fluid proteins) to whole blood levels of 50, 20, 10, 5, and 1%. Actim PROM®, Amnisure®, and ROM Plus® tests were performed on each sample in duplicate according to package insert instructions. Results were interpreted independently at 5, 10, 15, and 20 min by two obstetricians who were blinded to the concentrations of blood and amniotic fluid proteins in each sample. Results of each test were determined to be true positive, false negative, false positive, or true negative based on physician interpretation and whether amniotic fluid had been spiked into the samples in detectable concentrations. Overall accuracy, intraobserver concordance, and interobserver concordance, sensitivity, specificity, and predictive values for each test were calculated. Fisher exact test was used to compare test characteristics, with a p-value of <.05 considered significant.Results: Out of 120 tests performed, there were no false positive results for any test. Overall, ROM Plus® had better accuracy (97.9%) than Amnisure® (80.7%) or Actim® PROM (78.3%). Intra- and interobserver concordance were similar for all three tests (98–100%). ROM Plus® had significantly higher sensitivity than Amnisure® and Actim® PROM (p < .0001). There was no significant difference in sensitivity between Amnisure® and Actim® PROM (p = .51).Conclusion: ROM Plus® maintains strong test characteristics for the detection of amniotic fluid proteins in the setting of blood contamination, and performs significantly better than Amnisure® and Actim® PROM tests in the presence of blood.

Effects of Blood Contamination on Sealing Ability and Microhardness of Mineral Trioxide Aggregate Used as a Root-end Filling Material

Effects of Blood Contamination on Sealing Ability and Microhardness of Mineral Trioxide Aggregate Used as a Root-end Filling Material

Effect of Blood Contamination and Decontamination Procedures on the Microtensile Bond Strength of a New Self-etch Adhesive: An in vitro Study

ABSTRACT Aim The aim of the study was to evaluate the effect of blood contamination and decontamination procedures on the microtensile bond strength of a new self-etch adhesive before and after curing. Materials and methods A total of 90 human extracted mandibular molars were stored in 0.5% thymol solution and distilled water. Midcoronal sections were obtained using a diamond disk and the dentin surface was ground with 320 grit SIC abrasive paper. Universal self-etch adhesive (3M ESPC) and Filtex Z-250 resin composite were used. The dentin specimens were randomly divided into nine groups: Control group, group I—blood contamination before curing, group II—blood contamination before curing followed by air drying, group III—blood contamination before curing followed by rinsing with water and air drying, group IV—blood contamination before curing followed by rinsing with water, air dry, and reapplication of bonding agent, group V—blood contamination after curing, group VI—blood contamination after curing followed by air dry, group VII—blood contamination after curing followed by rinsing with water and air drying, group VIII—blood contamination after curing followed by rinsing with water, air dry, and reapplication of bonding agent. The microtensile bond strength was measured by universal testing machine and the data were analyzed by one-way analysis of variance (ANOVA) followed by Tukey's post hoc test. Results The contamination groups (I, V) showed the least bond strength followed by the decontamination groups (II, III, VI, VII). The reapplication groups (IV, VIII) restored the bond strength equal to control group. Clinical significance A contamination-free area is required for adequate adhesion. It is important to rule out measures to prevent and manage contamination, so as to achieve durable seal between composite resin and tooth surface. How to cite this article Shaikh A, Hegde V, Shanmugasundaram S. Effect of Blood Contamination and Decontamination Procedures on the Microtensile Bond Strength of a New Self-etch Adhesive: An in vitro Study. Int J Experiment Dent Sci 2017;6(2):80-83.

The Effect of Blood Contamination on the Chemical Characterization of Hydrated Mineral Trioxide Aggregates and Their Dentin-Interface: A Comparative Study

The presence of blood contamination could affect the chemical characterization of mineral trioxide aggregates as endodontic repair material during surgical approach. The aim of this study was to assess and compare the chemical characterization of two white mineral trioxide aggregates (ProRoot and Angelus) mixed with blood versus water. ProRoot and Angelus were mixed with either distilled water, fresh human blood, or diluted blood and analyzed using Fourier transform infrared spectroscopy. The same materials were packed inside holes in dentin blocks for scanning electron microscopy with energy-dispersive X-ray. Gray Portland cement was used as a control. The infrared spectra of unhydrate powders showed an increase in alite in ProRoot and Angelus, belite in Portland cement, and calcium hydroxide in Angelus. Upon hydration, changes in these bands were detected. Energy-dispersive X-ray displayed significantly higher calcium, aluminum, and phosphorous in hydrated Angelus and silicon in hydrated ProRoot (p < 0.05). No phosphorous was detected in ProRoot. Traces of iron were detected in blood groups. A granular pattern was observed at the hydrated material of all tested groups. Definitive gaps were detected at certain areas within hydrated material and its dentin-interface, particularly in blood-contaminated groups. It was supported with the appearance of new bands assigned to Amide I and II of blood protein. It was concluded that the presence of blood during the hydration process of mineral trioxide aggregates produced small gaps of protein impurities within the hydrated material, affecting its chemical behavior and dentin/material-interface integrity.

The effect of blood contamination on dislocation resistance of different endodontic reparative materials.

This study evaluated the retention characteristics of ProRoot mineral trioxide aggregate (MTA), RetroMTA, Supra MTA, and Biodentine biomaterials used to repair furcation perforations contaminated with blood. Furcal perforations measuring 1.3 mm in diameter and 2 mm in height were created in 96 mandibular first molar teeth, which were then randomly divided into the following two groups (n = 48): contaminated (+) or non-contaminated (-) with blood. The groups were subdivided into four groups (n = 12) according to the material used (ProRoot MTA, RetroMTA, Supra MTA, and Biodentine) to seal the perforations. The samples were allowed to set for 14 days and were then subjected to push-out testing. The results were analyzed using ANOVA, and the failure modes were examined using a surgical microscope. ProRoot MTA (+/-) and RetroMTA (+/-) exhibited superior bond strength values; in addition, there were no significant differences among these groups (P > 0.05). Biodentine (+) showed intermediate values that were sometimes statistically similar to the ProRoot MTA (+/-) and RetroMTA (+/-) groups (P > 0.05) and, at other times, the Biodentine (-) and Supra MTA (+/-) groups (P > 0.05). The lowest bond strength values were shown by the Biodentine (-) and Supra MTA groups (P > 0.05). "Adhesive failure mode" was the most frequently observed type for all tested materials. Blood contamination did not affect the dislocation resistance of materials.

Effect of Blood Contamination on Marginal Adaptation and Surface Microstructure of Mineral Trioxide Aggregate: A SEM Study.

Background and aims In various clinical situations, mineral trioxide aggregate (MTA) may come into direct contact or even be mixed with blood. The aim of the present study was to evaluate the effect of exposure to blood on marginal adaptation and surface microstructure of MTA. Materials and methods Thirty extracted human single-rooted teeth were used. Standard root canal treatment was carried out. Root-ends were resected, and retrocavities were prepared. The teeth were randomly divided into two groups (n = 15): in group 1, the internal surface of the cavities was coated with fresh blood. Then, the cavities were filled with MTA. The roots were immersed in molds containing fresh blood. In group 2, the aforementioned procedures were performed except that synthetic tissue fluid (STF) was used instead of blood. To assess the marginal adaptation, “gap perimeter” and “maximum gap width” were measured under scanning electron microscope. The surface microstructure was also examined. Independent samples t-test and Mann-Whitney U test were used to analyze the data. Results Maximum gap width and gap perimeter in the blood-exposed group were significantly larger than those in the STF-exposed group (p < 0.01). In the blood-exposed group, the crystals tended to be more rounded and less angular compared with the STF-exposed group, and there was a general lack of needle-like crystals. Conclusion Exposure to blood during setting has a negative effect on marginal adaptation of MTA, and blood-exposed MTA has a different surface microstructure compared to STF-exposed MTA.

The effect of blood contamination on equine synovial fluid analysis

Based on a systemic complete blood count and a synovial fluid sample, to develop a mathematical model enabling the approximation of corrected values for synovial fluid white blood cell (WBC) count, neutrophil percentage, and total protein concentration in samples of synovial fluid that were contaminated by blood. Peripheral venous blood and synovial fluid samples were obtained from ten horses. A pooled synovial fluid sample from each horse was separated into 2 mL aliquots, which were subsequently contaminated with a known percentage of autogenous blood (0 to 50% of the synovial fluid volume). A complete blood count, packed cell volume, total protein (TP) concentration, and differential cytological examination were performed in all the synovial fluid and venous blood samples. Regression analysis was used to generate a model to calculate non-contaminated synovial WBC count, TP concentration and synovial neutrophil percentage. Using a further five horses these models were applied in blinded fashion to contaminated synovial fluid samples. Calculated values were compared to non-contaminated measured values. Model results for synovial WBC count and TP concentration were not significantly different from measured values. Calculated neutrophil percentage of synovial fluid WBC was a mean of 6.6% higher than measured values and was significantly different. There was no effect of the severity of contamination (as a percentage of volume) on the ability of the models to predict any of the outcome variables. It is possible to calculate non-contaminated synovial fluid WBC and TP values, but not neutrophil percentage, from heavily contaminated samples. Further study would allow for improved prediction, validation and extrapolation to a wider horse population.

The effect of blood contamination on the compressive strength and surface microstructure of mineral trioxide aggregate

To investigate the effects of whole, fresh human blood contamination on compressive strength and surface microstructure of grey and tooth-coloured mineral trioxide aggregate (MTA). The materials investigated were grey ProRoot MTA Original (Dentsply Tulsa Dental, Johnson City, TN, USA) and tooth-coloured ProRoot MTA (Dentsply Tulsa Dental). Three groups of 10 custom-made cylindrical moulds (internal dimensions 6 +/- 0.1 mm length and 4 +/- 0.1 mm diameter) were filled with tooth-coloured MTA. In the control group, MTA was mixed with water and exposed to water. In the second group, MTA was mixed with water and exposed to whole, fresh human blood. In the third group, MTA was mixed with and exposed to whole, fresh human blood. These three groups were then duplicated using grey MTA, creating a total of 60 samples. A predetermined amount of MTA and appropriate liquid were triturated in a plastic mixing capsule then subjected to ultrasonic energy after placement in the moulds. After 4 days of incubation, specimens were subjected to compressive strength testing. The surface microstructure of one extra specimen in each group was examined using scanning electron microscopy. Data were subjected to a two-way anova. Regardless of MTA type, the mean compressive strength values of both experimental groups, which were in contact with blood, were significantly less than that of the control groups (P < 0.0001). In experimental groups in which MTA was mixed with water and exposed to blood, there was a significant difference (P < 0.0001) in compressive strength between tooth-coloured MTA (30.37 +/- 10.16 MPa) and grey MTA (13.92 +/- 3.80 MPa). When blood becomes incorporated into MTA, its compressive strength is reduced. In clinical situations in which blood becomes mixed with MTA, its physical properties are likely to be compromised.

Effects of Blood Contamination on Microtensile Bond Strength to Dentin of Three Self-etch Adhesives

This study evaluated the effects of blood contamination and decontamination methods during different steps of bonding procedures on the microtensile bond strength of two-step self-etch adhesives to dentin. Sixty extracted human molars were ground flat to expose occlusal dentin. The 60 molars were randomly assigned to three groups, each treated with a different two-step self-etch adhesive: Clearfil SE Bond, AdheSE and Tyrian SPE. In turn, these groups were subdivided into five subgroups (n = 20), each treated using different experimental conditions as follows: control group-no contamination; contamination group 1-CG1: primer application/ contamination/primer re-application; contamination group 2-CG2: primer application/contamination/wash/dry/primer re-application; contamination group 3-CG3: primer application/adhesive application/light curing/contamination/ adhesive re-application/light curing; contamina- tion group 4-CG4: primer application/adhesive application/light curing/contamination/wash/ dry/adhesive re-application/light curing. Composite buildup was performed using Z250. After 24 hours of storage in distilled water at 37 degrees C, the bonded specimens were trimmed to an hourglass shape and serially sectioned into slabs with 0.6 mm2 cross-sectional areas. Microtensile bond strengths (MTBS) were assessed for each specimen using a universal testing machine. The data were analyzed by two-way ANOVA followed by a post hoc LSD test. SEM evaluations of the fracture modes were also performed. The contaminated specimens showed lower bond strengths than specimens in the control group (p < 0.05), with the exception of CG1 in the Clearfil SE group and CG2 and CG3 in the Tyrian SPE group. Among the three self-etch adhesives, the Tyrian SPE group exhibited a significantly lower average MTBS compared to the Clearfil SE Bond and AdheSE (p < 0.05) groups. Based on the results of the current study, it was found that blood contamination reduced the MTBS of all three self-etch adhesives to dentin, and water-rinsing was unable to overcome the effects of blood contamination.

Effects of blood on bone cement made of calcium phosphate: Problems and advantages

In recent years, calcium phosphate cements (CPCs) have frequently been used as bone substitutes in the field of orthopedic surgery. When CPC is used as a bone substitute in vivo, blood contamination is unavoidable. To date, however, no detailed study has been conducted focusing on how the physical properties of CPCs would change under the influence of blood. In this study, the effects of blood contamination on Biopex-R (BPR, PENTAX, Tokyo) are examined in vitro and in vivo. The compressive strength of BPR after setting decreased depending on the amount of contaminating blood. The BPR, which has set in vivo, not only has a fragile surface due to the contamination by blood, but also has a propensity to shorten and be destroyed during the early postoperative stage, especially in the bone exposed to loads. On the other hand, radiographic and histological features in vivo indicated that the absorption and the bone replacement of BPR were stimulated by blood contamination. In the clinical evaluation, the patient's own peripheral venous blood was added to the BPR. One year after the surgery, the absorption was noted around the hardened BPR. To advance CPCs (including BPR) as bioabsorbable bone replaceable materials, it is essential to utilize the patient's own blood in combination with the CPC.

Effect of Blood Contamination with 1-step Self-etching Adhesives on Microtensile Bond Strength to Dentin

This study evaluated the effect of blood contamination and decontamination methods on the microtensile bond strength of 1-step self-etching adhesive systems to dentin contaminated after adhesive application and light curing. Three commercially available "all-in-one" adhesives (One Up Bond F, Xeno III and Adper Prompt L-Pop) and 1 resin composite (Clearfil AP-X) were used. Third molars that had been stored in distilled water with 0.5% thymol at 4 degrees C were ground with #600 SiC paper under running water to produce a standardized smear layer. The specimens were randomly divided into groups according to the 3 adhesive systems. The adhesive systems were used under 3 conditions: no contamination, which was the control (C); contamination of the light-cured adhesive surface with blood and reapplication of adhesive (Contamination 1) and contamination of the light-cured adhesive surface with blood, then washing, drying and reapplication of the adhesive (Contamination 2). Following light curing of the adhesive, the resin composite was placed in 3 increments up to a 5-mm-thick layer on the bonded surface. All specimens were stored in distilled water at 37 degrees C for 24 hours. The microtensile bond strength was measured using a universal testing machine (EZ test), and data were analyzed by 1-way ANOVA followed by the Duncan test to make comparisons among the groups (p=0.05). After debonding, 5 specimens were selected from each group and examined in a scanning electron microscope to evaluate the modes of fracture. For all adhesives, contamination groups showed lower bond strength than the control (p<0.05). There was no statistically significant difference among the control groups (p>0.05). For Xeno III and Adper Prompt L-Pop, contamination group #2 showed the lowest bond strength among the groups (p<0.05). For One Up Bond F, contamination group #2 showed higher bond strength than contamination group #1 but showed no statistical significance between them (p>0.05).

Effect of Blood Contamination on Retention Characteristics of MTA When Mixed With Different Liquids

Simulated furcation perforations were repaired with and without blood contamination utilizing tooth-colored mineral trioxide aggegrate (MTA) mixed with either MTA liquid (sterile water), lidocaine, or saline. Samples underwent Instron testing at either 24 or 72 hours and at 7 days. Data were analyzed using a 3-way ANOVA and post-hoc testing using Tukey’s true test for significance. All of the 72-hour samples displayed significantly greater resistance to displacement than the 24-hour samples. All of the 7-day samples displayed significantly greater resistance to displacement than the 24-hour and 72-hour samples. Non-contaminated samples displayed significantly greater resistance to displacement than their blood-contaminated counterparts at 7 days. Non-contaminated samples mixed with sterile water, lidocaine, or saline performed similarly at all time periods. Allowing tooth-colored MTA to set undisturbed for 72 hours or longer prior to placement of a coronal restoration may decrease the chance of MTA displacement in furcation perforation repairs.

Effect of blood contamination on delta 450 bilirubin measurement: an in vitro comparison of two corrective methods.

Amniotic fluid bilirubin peaks (1.6–1.8 mg/L) at ∼19–22 weeks of gestation (1). An increase in amniotic fluid bilirubin concentration after 25 weeks indicates extensive hemolysis of fetal blood and potential erythroblastosis fetalis in which amniotic fluid bilirubin can reach ∼10 mg/L (2)(3). Bilirubin in amniotic fluid can be measured by direct spectrophotometry, most commonly by the “delta 450 bilirubin” method (4). Contaminating pigments, such as hemoglobin, can interfere in the method. Chloroform extraction has been used to extract bilirubin, leaving water-soluble pigments in the aqueous layer. The delta 450 bilirubin is then measured in the chloroform fraction and interpreted by use of the Liley plot (5)(6). A delta 410 correction formula also exists that theoretically accounts for hemoglobin interference. The delta 410 absorbance is measured and used to correct the delta 450 bilirubin (4)(6)(7). Our objective was to examine the effect of hemolyzed-whole-blood contamination on the delta 450 bilirubin measurement and to compare corrective methods. After receiving Institutional Review Board approval, we pooled amniotic fluid specimens collected for physician-ordered fetal lung maturity assessment (stored at −20 °C). Visibly bloody or meconium-contaminated samples were not used. The pool was centrifuged at 1100 g for 5 min, and the supernatant was filtered through a 22 μm AP 20 prefilter (Millipore Corp.) and a 1.2 μm RA filter (Millipore). Bilirubin was undetectable in the pool by delta 450 measurement. We prepared a 600 mg/L stock solution of unconjugated bilirubin (ICN Biomedicals Inc.) by dissolving 6.0 mg of bilirubin in 0.1 mL of dimethyl sulfoxide (Sigma Chemical Co.) and 0.2 mL of sodium carbonate (100 mmol/L). The solution was vortex-mixed until the bilirubin was dissolved. We then added 9.5 mL of pooled amniotic fluid, followed by 0.2 mL of HCl (100 mmol/L) to …

Implications of blood contamination for assessment of local cellular immunity in the endocervix.

Cervical cytobrushes provide a tool to sample endocervical T cells for assessment of local immunity. However, most previous studies in HIV-seropositive women have excluded samples containing blood and hence have analyzed selected populations of patients. As determined by multiple-parameter flow cytometric analysis of T lymphocytes from two sequential cytobrushes and concurrently collected blood samples, this study found a minimal effect of blood contamination on cervical T cell phenotypic parameters in normal women. The consequences of blood in endocervical samples will ultimately depend on the design and objective of each study, but these data suggest studies could be more inclusive and should not automatically discard samples that contain red blood cells.