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PubMed1998

Influence of different vehicles on the antibacterial effects of calcium hydroxide.

This study evaluated the influence of three different vehicles on the antibacterial activity of calcium hydroxide against four bacterial species commonly found in endodontic infections. For this purpose, a broth dilution test using 24-well cell culture plates was performed. Results showed that all pastes were effective in killing the bacteria tested, but at different times. The calcium hydroxide/camphorated paramonochlorophenol/glycerin paste was the most effective against the four bacterial strains tested.

Bacteria, Anaerobic↗
PubMed1998

Recontamination of coronally unsealed root canals medicated with camphorated paramonochlorophenol or calcium hydroxide pastes after saliva challenge.

This in vitro study evaluated the ability of some medications to prevent recontamination of coronally unsealed root canals by bacteria from saliva. The medications tested were camphorated paramonochlorophenol (CPMC) applied in cotton pellets in the pulp chamber; calcium hydroxide/saline solution paste filling the root canal; and calcium hydroxide/CPMC/glycerin paste also filling the root canal. Medicated canals were exposed to saliva, and the number of days required for total recontamination to occur was recorded. Canals medicated with CPMC in cotton pellets were thoroughly recontaminated within an average of 6.9 days. Canals filled with calcium hydroxide/saline solution and calcium hydroxide/CPMC/glycerin showed entire recontamination within an average of 14.7 and 16.5 days, respectively. Calcium hydroxide pastes were significantly more effective than CPMC (p < 0.05).

Bacteria↗
PubMed1999

Removal efficiency of calcium hydroxide dressing from the root canal.

The aim of this study was to investigate whether differences in the composition of calcium hydroxide (Ca(OH)2) preparations influence the removal efficiency of irrigation solutions used in combination with filing of the canal. Three Ca(OH)2 preparations were used: Calxyl, Pulpdent paste, and chemically pure Ca(OH)2 mixed with distilled water. Fifty-one single-rooted extracted human teeth were prepared with a step-back technique and divided into groups A, B, and C. In each group, 15 teeth were assigned to each Ca(OH)2 preparation while the remaining two served as positive and negative controls. Each group of treated teeth was divided into three subgroups of five teeth each: subgroup I--canals were irrigated with saline, filed with a #25 file, and finally flushed with saline; subgroup II--canals were irrigated with NaOCl, filed with a #25 file, and finally flushed with NaOCl; and subgroup III--canals were irrigated with NaOCl, filed with a #25 file, and finally flushed with tetrasodium EDTA. Canal sections were then photographed, and the percentage ratios of Ca(OH)2 coated area to the total canal surface area were calculated by image processing analysis. Results revealed: (a) none of the methods efficiently removed all dressing from the walls, and (b) concentration of the paste used had little effect on the efficacy of the methods applied for the removal of the dressing. Excipients (i.e. methylcellulose contained in Pulpdent) possibly effect retention of Ca(OH)2.

Calcium Hydroxide↗
PubMed1999

Reaction of rat connective tissue to implanted dentin tubes filled with mineral trioxide aggregate or calcium hydroxide.

This study was conducted to observe the rat subcutaneous connective tissue reaction to the implanted dentin tubes filled with calcium hydroxide or mineral trioxide aggregate. The animals were sacrificed after 7 and 30 days, and the specimens were prepared for morphological study. Some undecalcified specimens were prepared for histological analysis with polarized light and Von Kossa technique for calcium. The results were similar for both studied materials. At the tube openings, there were Von Kossa-positive granules that were birefringent to polarized light. Next to these granulations, there was an irregular tissue like a bridge that was Von Kossa-positive. The dentin walls of the tubes exhibited in the tubules a structure highly birefringent to polarized light, usually like a layer and at different depths. It is possible that the mechanism of action of both materials has some similarity.

Aluminum Compounds↗
PubMed1999

Dentinal tubule penetration of root canal sealers after root canal dressing with calcium hydroxide.

The purpose of this study was to evaluate the dentinal tubule penetration of root canal sealers after root canal dressing with calcium hydroxide (Ca(OH)2). Forty-two single-rooted teeth were instrumented to size 60. Six teeth served as the control group, and the remaining teeth were assigned to two groups. Root canals of the first group were filled with the Ca(OH)2 paste; the second group was filled with TempCanal, and all were incubated for 7 days. The samples were either irrigated with only NaOCl or with EDTA, followed by NaOCl to remove Ca(OH)2. All of the teeth were obturated with CRCS, AH26, and Ketac Endo by a lateral condensation technique. The specimens were then kept at the same conditions for another 7 days, and then all of the roots were prepared for scanning electron microscopic evaluation. Scanning electron microscopic examination revealed that Ca(OH)2 was not completely removed from the root canal surfaces, and root canal sealers did not penetrate into the dentinal tubules when only NaOCl was used. EDTA followed by NaOCl irrigation resulted in complete removal of Ca(OH)2 and root canal sealers penetrated into the dentinal tubules.

Bismuth↗
PubMed1981

Secondary response to boostering by purified aluminium-hydroxide-adsorbed tetanus anatoxin in aging and in aged adults.

Immunologic responsiveness to boostering by tetanus anatoxin adsorbed on aluminium hydroxide was studied in subjects aged 60 to 91 years. They were primed 8 years previously with two injections given 40 days apart plus one injection one year later. Aging and aged subjects were shown to maintain their ability for tetanus antibody production in amounts sufficient to protect them from the disease. Therefore subjects aged above 60 years are recommended to be included into active immunizations against tetanus.

Adsorption↗
PubMed1999

Effect of magnesium hydroxide administration on iron absorption after a supratherapeutic dose of ferrous sulfate in human volunteers: a randomized controlled trial.

STUDY OBJECTIVE: Animal models have demonstrated that administration of magnesium hydroxide (MgOH) decreases serum iron levels after an iron overdose. We designed this study to determine the effect of MgOH administration on iron absorption and adverse effects after a supratherapeutic dose of ferrous sulfate in healthy male volunteers. METHODS: We conducted a prospective, unblinded, randomized trial involving 16 healthy, fasting men. All subjects ingested a 10-mg/kg dose of elemental iron in the form of ferrous sulfate. One-half hour after the iron dose, the 8 subjects in the experimental group were given 5 mg of MgOH for every 1 mg of ingested elemental iron. Serum iron levels were obtained at baseline and at each subsequent hour for 6 or 7 hours. Serum magnesium levels were obtained at baseline, after 3 hours, and after 6 hours. Side effects were recorded hourly. Serum iron levels between groups were compared by repeated-measures ANOVA and ANCOVA. The 95% confidence intervals (CIs) for the difference in serum iron levels between groups at each time point and for the difference in peak serum iron level between groups were calculated. RESULTS: Baseline mean serum iron levels did not differ between the 2 groups (P =.28). There were no statistical differences between groups (P =.20). Mean serum iron levels at each time point and peak serum iron levels did not differ significantly between groups. The mean peak serum iron level was 300.8 micrograms/dL in the control group and 272.5 micrograms/dL in the experimental group. CONCLUSION: Administration of MgOH does not affect iron absorption in humans after a supratherapeutic dose of iron when the ratio of MgOH to elemental iron is 5:1.

Adult↗
PubMed2002

Immune responses of goats against foot-and-mouth disease quadrivalent vaccine: comparison of double oil emulsion and aluminium hydroxide gel vaccines in eliciting immunity.

The epidemiological role of small ruminants in foot-and-mouth disease (FMD) outbreaks has been generally neglected. Although, the disease in these species is sub-clinical in nature, their role as virus carriers represents a reservoir for further infection and spread of disease. Data on the usefulness of polyvalent FMD vaccine (FMDV) in goats is scant. Thus, the present study was undertaken to evaluate the benefits of a highly potent polyvalent FMDV in goats. In the present investigations, FMDV quadrivalent double oil emulsion (Montanide ISA 206) vaccines were tested in goats at reduced doses of 2 ml per animal (antigen payload 3.5 microg per serotype per dose). The oil adjuvant elicited superior immune response at any given period than aluminium hydroxide gel (AGS) vaccine and the rapidity of development of response was quicker. The duration of immunity also appeared to be maintained for long period. The differences in immune response between two adjuvant groups were statistically significant (P<0.05). The differences were apparent even in kinetics of immune response. Unlike cattle, goats were found to be late responders for oil-adjuvanted vaccine. Our results indicate possible universal usage of double oil emulsion vaccines for disease control programs irrespective of species of animals.

Adjuvants, Immunologic↗
PubMed2000

Kinetic study of the reaction between sulfur dioxide and calcium hydroxide at low temperature in a fixed-bed reactor.

A quantitative study of the influence of inlet sulfur dioxide concentration (600-3000 ppm), relative humidity (20-60%), reactor temperature (56-86 degrees C) and different amounts (0-30 wt.%) of inorganic additives (NaCl, CaCl(2) and NaOH) on gas desulfurization has been carried out in a continuous downflow fixed-bed reactor containing calcium hydroxide diluted with silica sand. Results show that the reaction rate does not depend on sulfur dioxide partial pressure (zero-order kinetics) and that the temperature and the relative humidity have a positive influence on reaction rate. An apparent activation energy of 32 kJ/mol Ca(OH)(2) has been estimated for the reaction. An empirical reaction rate equation at 71.5 degrees C and 36.7% relative humidity that includes the type and amount of additive is proposed. It has been found that calcium chloride is the best additive studied because it allows for a higher degree of sulfur dioxide removal.

Air Pollution↗
PubMed1990

Simultaneous determination of ampicillin and sulbactam by liquid chromatography: post-column reaction with sodium hydroxide and sodium hypochlorite using an active hollow-fibre membrane reactor.

A high-performance liquid chromatographic method has been developed for the simultaneous determination of ampicillin (ABPC) and sulbactam (SBT) in serum and urine. The method involves separation of ABPC and SBT from the background components of serum and urine on a C18 column, post-column reaction with sodium hydroxide and sodium hypochlorite using an active hollow-fibre membrane reactor, and detection at 270 nm. At ABPC and SBT concentrations of 10 and 5 micrograms/ml in urine and serum samples, the precisions (relative standard deviations) were 0.9-2.5% (n = 8). The detection limits were 20 and 5 ng for ABPC and SBT, respectively, at a signal-to-noise ratio of 3.

Ampicillin↗
PubMed2001

Evaluation of potassium hydroxide for wet mount preparation of stool for detection of intestinal parasites.

Potassium hydroxide (KOH) is widely used in the wet mount preparation of various clinical specimens for demonstration of fungi and fungal elements. In the present study we have evaluated the use of KOH in the wet mount preparation of fresh stool specimens for the demonstration of intestinal parasites. The KOH wet mount of stool was compared with saline, iodine and lacto-phenol cotton blue (LPCB) wet mount preparations of stool. A total of 855 fresh stool specimens were examined in the study of which 419 specimens were found to be positive for either trophozoites, cysts, ova or larvae of different parasites by all these methods. A total of 309 stool specimens were positive by KOH preparation of stool, while 289, 245 and 208 stool specimens were positive by LPCB, iodine and saline preparations respectively. The KOH was found to be effective in lysing the faecal debris, faecal mass and other artifacts without affecting many of the parasitic ova, cysts and larvae in the stool smears. The parasitic ova, cysts and larvae were impacted by the use of 10% KOH and could be easily visualized, detected and identified against a clear background in the stool smear I hr after preparation of KOH wet mount. From these findings we recommend the routine use of KOH wet mount of stool for demonstration of intestinal parasites in a parasitology laboratory.

Animals↗
PubMed1997

Performance of aluminium hydroxide gel and oil adjuvant rabies vaccines in bovines.

Rabies vaccine containing aluminium hydroxide and oil adjuvant were compared for their efficacy in inducing serological response in 11-12 months old calves. The serum antibody titres were estimated at 0, 21, 90, 180 and 360 dpv by RFFIT. Both groups of calves responded serologically in a similar way and there was no significant variation in serum antibody titres in animals between both groups of animals. The serum antibody titres in both groups of animals were above protective levels on 360 dpv.

Adjuvants, Immunologic↗
PubMed2003

Efficacy of chlorhexidine- and calcium hydroxide-containing medicaments against Enterococcus faecalis in vitro.

OBJECTIVE: We sought to assess the efficacy of chlorhexidine (CHX) and calcium hydroxide, Ca(OH)(2), against Enterococcus faecalis in vitro. STUDY DESIGN: The effect of CHX (0.2% and 2% in gel or solution) and Ca(OH)(2) (alone or with 0.2% CHX gel) was evaluated by using the agar diffusion test and an in vitro human root inoculation method, to measure zone of inhibition or bacterial growth with optical density analysis, respectively. For optical density analysis, samples from infected root canals were collected after 7 days of medication and were cultured for 24 hours in brain-heart infusion to detect viable bacteria. RESULTS: In the agar diffusion test, CHX was effective against E faecalis in a concentration-dependent fashion, but Ca(OH)(2) alone had no effect. In the root canal inoculation test, CHX was significantly more effective against E faecalis than Ca(OH)(2) was (P < .05), but there were no significant differences between the modes of medication or concentrations of CHX. CONCLUSIONS: CHX is effective against E faecalis in vitro. Further in vivo studies are needed to confirm the value of CHX in clinical treatment.

Anti-Infective Agents, Local↗
PubMed2003

Evaluation of the antibacterial potential of tetracycline or erythromycin mixed with calcium hydroxide as intracanal dressing against Enterococcus faecalis in vivo.

OBJECTIVE: We evaluated the intracanal antibacterial potential of tetracycline or erythromycin mixed with calcium hydroxide (CH) against enterococci in vivo. STUDY DESIGN: Fifty-five teeth in which enterococci were present were dressed for 1 month with either tetracycline (28 teeth) or erythromycin (27 teeth) mixed with CH. RESULTS: The tetracycline mixture was effective against enterococci in 22 teeth (79%). In 7 teeth, other microorganisms were recovered, resulting in a total antimicrobial effect of 54%. The corresponding results for erythromycin were 96% and 56%. CONCLUSIONS: The antimicrobial treatment of CH in combination with either erythromycin or tetracycline had a significant effect on enterococci, but the overall antimicrobial effect was relatively weak. Erythromycin mixed with CH seems to be a valuable option in the battle against monoinfections of enterococci.

Adult↗
PubMed1995

Human pulp response after partial pulpotomy with two calcium hydroxide products.

Twenty human permanent teeth were used to study the pulpal response of two calcium hydroxide products, Dycal and Pulpdent Multi-Cal, after partial pulpotomy. Teeth were extracted at 4 months, fixed, and prepared for histologic examination. All 10 teeth treated with Dycal showed complete soft tissue healing and bridge formation. No stained bacteria were seen throughout the serial sections. One tooth treated with Dycal showed acceptable histologic results, dentin deposition in the root canal. Six cases dressed with Pulpdent Multi-Cal showed acceptable histologic results, whereas four teeth showed severe inflammation or necrosis associated with bacterial penetration into the pulp tissue. Clinically, one tooth treated with Pulpdent Multi-Cal showed pulpal pain and was extracted at 90 days. Our data support the thesis that human permanent pulps will promote tissue healing and dentin bridge formation as long as bacterial microleakage is excluded.

Bacteria↗
PubMed1997

Calcium hydroxide ameliorates tobramycin toxicity in cultured chick tibiae.

Results from this laboratory have shown that bone metabolism is directly related to extracellular pH and that high concentrations of tobramycin released from impregnated polymethylmethacryrate (PMMA) beads has pH-dependent toxic effects on bone. In the present study, beneficial effects of calcium hydroxide-impregnated PMMA were investigated regarding tobramycin toxicity and bone metabolism in chick embryo tibiae in vitro. Also using Ca(OH)2 as a pH regulator, the antibiotic efficacy of tobramycin-impregnated PMMA was evaluated with respect to inhibition of Staphylococcus aureus growth. When Ca(OH)2 was added to PMMA beads containing tobramycin, the beads released hydroxyl and calcium ions into the culture medium and released more antibiotic than beads containing only tobramycin. Bone metabolism (glycolysis, total protein synthesis, and collagen synthesis) was enhanced by Ca(OH)2-impregnated beads with or without tobramycin. Additionally, bacterial growth was inhibited more strongly when S. aureus was incubated with tobramycin- and Ca(OH)2-impregnated PMMA disks than with disks containing only tobramycin. This study demonstrates the feasibility of adding Ca(OH)2 to tobramycin-impregnated PMMA beads as a regulator of local pH and a promoter of bone metabolism for protection of bone when high concentrations of tobramycin are used to treat osteomyelitis. It also suggests that lower concentrations of antibiotic may be effective if Ca(OH)2 and tobramycin are administered simultaneously.

Animals↗
PubMed1979

The inactivation of viruses in cattle and pig slurry by aeration or treatment with calcium hydroxide.

Porcine enterovirus type 2 or porcine adenovirus type 3 were seeded into samples of pig slurry, and a bovine enterovirus was seeded into cattle slurry, and samples of the slurry were aerated in the laboratory for 21 days. The viruses were inactivated more rapidly in the aerated slurry than in control slurry which was not aerated. The difference in inactivation rate was greatest for the porcine adenovirus and least for the bovine enterovirus. Inactivation of the porcine enterovirus in aerated distilled water and in aerated, autoclaved pig slurry proceeded at a similar rate as in the same materials which were not aerated. Ten samples of aerated slurry were collected from an aeration tank which received weekly additions of raw pig slurry which was sampled at the same times. Each sample yielded a porcine enterovirus after concentration with the polyelectrolyte PE-60, but in three comparative titrations the viral infectivity titre in concentrates of the raw slurry was at least 1000 times greater than in the aerated slurry. Porcine enterovirus type 2 and porcine adenovirus type 3, which were seeded into pig slurry, and a bovine enterovirus seeded into cattle slurry, were inactivated by treatment of the slurry with calcium hydroxide at pH 11.5. The inactivation rate was highest for the bovine enterovirus and lowest for the porcine adenovirus.

Adenoviridae↗
PubMed2003

Layered double hydroxides: an attractive material for electrochemical biosensor design.

Electrochemical biosensors for phenol determination were developed based on the immobilization of polyphenol oxidase (PPO) within two different clay matrixes, one anionic (layered double hydroxide, LDH) and the other cationic (Laponite). The biosensor based on the enzyme immobilized in [Zn-Al-Cl] LDH shows greater sensitivity (7807 mA M(-1) cm(-2)) and maximum current (492 microA cm(-2)). Biosensor characteristics, such as Michaelis-Menten constant, recycling constant, activation energy, and permeability highlight the advantages of LDH matrixes to immobilize PPO. It appears that LDH provides a favorable environment to PPO activity. The best PPO/[Zn-Al-Cl] configuration was used to determine five different phenol derivatives reaching extremely sensitive detection limits (< or = 1 nM).

Biosensing Techniques↗