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PubMed2006

In vitro evaluation of the susceptibility of endodontic pathogens to calcium hydroxide combined with different vehicles.

The aim of this study was to investigate in vitro the antimicrobial activity of calcium hydroxide [Ca(OH)2] in combination with different vehicles against endodontic pathogens. For such purpose, a broth dilution test was performed. Pastes were prepared with Ca(OH)2 powder and the following vehicles: sterile water, glycerin, camphorated monochlorophenol (CMCP), CMCP + glycerin, polyethyleneglycol and CMCP + polyethyleneglycol. The time required for the pastes to produce negative cultures against the tested microorganisms was recorded and analyzed statistically using the Kruskal Wallis test at 5% significance level. Timing for pastes to eliminate the aerobic and facultative anaerobic microorganisms ranged from 6 to 24 h, while strict anaerobic microorganisms were inhibited within 30 s to 5 min. Microbial susceptibility, ranked from weakest to strongest, can be presented as follows: Enterococcus faecalis (the most resistant microorganism), Candida albicans, Staphylococcus aureus, Porphyromonas gingivalis, Porphyromonas endodontalis and Prevotella intermedia (the last two microorganisms required the same time to be eliminated). In conclusion, calcium hydroxide pastes needed more time to eliminate facultative than anaerobic microorganisms. These findings suggest that the antimicrobial property is related both to paste formulation and to microbial susceptibility.

Anti-Bacterial Agents↗
PubMed2005

Determination of cadmium in spring water by graphite-furnace atomic absorption spectrometry after coprecipitation with ytterbium hydroxide.

A coprecipitation method with ytterbium hydroxide was studied for the determination of cadmium in water samples by graphite-furnace atomic absorption spectrometry. Up to 40 ng of cadmium in water samples was quantitatively coprecipitated with ytterbium hydroxide at pH 8.0-11.2. The concentration factor was 100 fold. The coprecipitated cadmium was sensitively determined without any influence of ytterbium and the calibration curve was linear from 0.1 to 4 ng/mL of cadmium. The detection limit (signal/noise = 2) was 2.9 pg/mL in 100 mL of the initial sample solution. Twenty-nine diverse ions tested did not interfere with the determination in at least a 10000-fold mass ratio to cadmium. The proposed method was successfully applied to the determination of cadmium in spring water.

Cadmium↗
PubMed1984

Response of milking cows fed a high concentrate, low roughage diet plus sodium bicarbonate, magnesium oxide, or magnesium hydroxide.

To determine the ability of mineral supplements to elevate depressed milk fat percent, we placed 42 Holstein cows in early to midlactation in seven blocks and assigned each to one of six treatments: control (25% corn silage and alfalfa haylage, 75% concentrate, mostly corn, dry matter); control plus magnesium oxide ground to pass a .425-mm sieve; control plus prilled magnesium oxide sieved to between 1.70 and .425 mm; control plus sodium bicarbonate; control plus reactive powdered magnesium oxide to pass a 45 microns sieve; and control plus powdered magnesium hydroxide. Sodium bicarbonate was 1% of diet as fed, magnesium oxide .5%, magnesium hydroxide .7% later reduced to .5%. Cows were fed control ration for 3 wk to induce milk fat depression, then were changed to treatment rations for 5 wk. Five cows (unblocked) were continued on each dietary treatment for a digestibility study after the feeding trial. All mineral supplements produced greater milk fat percent and yield of milk fat per day than control and all magnesium treatments produced greater milk fat percent than sodium bicarbonate. Magnesium oxide passing a .425-mm sieve produced the greatest increase of milk fat percent. Milk production was most for sodium bicarbonate treatment. Supplementation with magnesium increased ruminal magnesium concentration by factors of 1.26 to 3.75. Blood serum, urine, and fecal magnesium concentrations and fecal pH were more for cows fed magnesium than those fed sodium bicarbonate treatments. Kidney filtration ratios of element to creatinine increased for magnesium when diets were supplemented with magnesium and increased for phosphorus and sodium when diets were supplemented with sodium bicarbonate.

Animal Feed↗
PubMed2006

An in vitro evaluation of pH variations in calcium hydroxide liners.

The purpose of this present study was to determine the pH changes of five different commercially available calcium hydroxide liners and variations of pH at different time intervals. The following commercially available materials were investigated: Dycal (LD Caulk); Calcimol (Vocco Products); calcium hydroxide powder (Deepti Products); Calcimol LC (Vocco Products); Lime-Lite (Pulpdent Corporation). Five samples were prepared from each liner. The pH measurements were recorded at time intervals of 1 h, 24 h, 3 days and 7 days after mixing of the liner. The pH variations of each material at the given time intervals were recorded and the means were calculated. Comparison of the mean values at all time intervals with the statistical analysis showed significantly high differences (P < 0.001) between pH values induced by each material at all time intervals. Among the water-insoluble products, Dycal had the strongest alkaline effect after 7 days interval. The materials that chemically hardened produced higher pH values than materials that hardened by a visible light source after 7 days.

Analysis of Variance↗
PubMed1976

Treatment of non-vital permanent incisors with calcium hydroxide. VI. A clinical, microbiological and radiological evaluation of treatment in one sitting of teeth with mature or immature root.

The purpose of the investigation was clinically, microbiologically and radiologically to assess the effect of calcium hydroxide as a temporary root-filling inserted in the same sitting as root canal debridement in non-vital permanent incisors with mature and immature root, infected or uninfected root canal and with or without radiologically demonstrated periapical bone changes. The material consisted of 141 teeth divided in 3 groups in which mechanical cleansing was accompanied by flushing with sterile saline and sodium hypochlorite solutions giving 0.5% or 5.0% active chlorine, respectively. Microbiological samples were taken from root canals after extirpation of necrotic pulp tissue, after completed cleansing of the root canal and 3 and 6 month after treatment. Results of treatment were evaluated from the radiographs taken before treatment and at the 3 and 6 month follow-ups. Complication, pain and an abscess, occurred in 2 cases, 2 and 5 days, respectively, after treatment. No statistical correlation between occurrence of samples that gave growth, taken from the root canals at 3 (8%) or 6-month control (9%) and 1) bacteriological status of the root canal prior to filling with calcium hydroxide, 2) the development of the root or 3) periapical healing at 3 or 6 month follow-up could be ascertained. Periapical bone healing at the end of 6-months observation period was noted in 61 teeth (46%), regression of periapical bone lesions in 64 (49%) and no periapical healing in 6 (5%). The only difference in healing pattern, statistically significant on 0.1% level, was found in the group of teeth flushed with 5.0% sodium hypochlorite. At 3 month control they showed percentually less cases with regression and more cases with no healing of periapical bone lesions than the teeth in the other two groups. It was concluded that treatment in one sitting can be done routinely, irrespective of the initial status, in all those cases where no other treatment is possible. If the periodontium or the periapical bone are injured during cleansing procedures or if necrotic rests are not pressed out through the apical foramen, no complications after treatment need to be feared.

Adolescent↗
PubMed2002

Calcium hydroxide root canal dressing. Histopathological evaluation of periapical repair at different time periods.

The objective of this study was to evaluate periapical and apical repair using calcium hydroxide root canal dressings for different lengths of times in teeth with induced chronic periapical lesions. A total of 61 root canals of maxillary and mandibular premolars from 4 dogs were used. After mechanical preparation of the root canals using the crown-down technique, and 5.25% NaOCl as irrigating solution, the apical foramen was enlarged in all cases. A calcium hydroxide root canal dressing was applied. The control group did not receive a root canal dressing. The animals were killed at 7, 15 or 30 days. After histological preparation, serial sections were stained with hematoxylin-eosin and Mallory's trichrome. The best histopathological results occurred at 15 and 30 days, and the worst results occurred at 7 days and in the control group.

Alveolar Bone Loss↗
PubMed2003

[Radiation doses deriving from patients treated with (166)Ho-ferric hydroxide].

AIM: To estimate radiation doses deriving from patients treated with (166)Ho ferric hydroxide. METHODS: For radiation synoviorthesis about 900 +/- 100 MBq (166)Ho ferric hydroxide was injected into the knee joint of 16 patients. To estimate the radiation exposure of persons in the neighbourhood of the patients measurements of the dose rates were performed at 0.5 m, 1 m and 2 m distance of the treated joint 10 min after tracer injection. Measurements were carried out with and without radiation protection devices of the syringe. RESULTS: The initial values of the dose rate were 11.9 micro Sv/h at 0.5 m, 3.5 micro Sv/h at 1 m and 1 micro Sv/h at 2 m distance, respectively. The whole body doses were 2.9 micro Sv for the physician and 4.6 micro Sv for the technologist. The finger doses for the technologist and the physician were ranging from 65 to 111 micro Sv. After discharge at home other persons might receive 118 micro Sv. CONCLUSION: Our results, under very strict assumptions, clearly demonstrate that the calculated radiation exposure to medical and non medical personnel is well below the maximum annual dose limit. The use of any additional radiation protection device as syringe shielding does not significantly lower radiation exposure.

Fingers↗
PubMed2004

Direct detection of trace haloacetates in drinking water using microbore ion chromatography. Improved detector sensitivity using a hydroxide gradient and a monolithic ion-exchange type suppressor.

A highly sensitive gradient microbore ion chromatographic method was developed with electrolytically generated hydroxide eluents for the determination of low microg/L levels of chloroacetate, bromoacetate, trifluoroacetate, dichloroacetate, chlorodifluoroacetate, dibromoacetate, trichloroacetate, bromodichloroacetate and dibromochloroacetate disinfectant by-products formed as a result of chlorination of drinking waters. The possibility of using a packed bed Dionex Atlas suppressor with a hydroxide gradient at microbore flow rates was investigated in order to reduce baseline noise levels. The Atlas suppressor displayed a very significant reduction in noise levels compared to the standard alternative ASRS Ultra suppressor, reducing noise by a factor of 15-20 in some cases, allowing trace haloacetic acids (HAs) to be seen with the direct injection of 100 microL of treated water, with prior chloride and sulfate removal. To lower detection limits even further, a solid phase extraction was employed to preconcentrate HAs, resulting in detection limits of between 0.09 and 21.5 microg/L. The method was applied to the determination of HAs in environmental samples and standard addition curves for three drinking water samples were carried out for both direct injection and preconcentration methods. R2 values in both cases were > or =0.98. Combined content for US Environmental Protection Agency regulated HAs in the three drinking water samples from Dublin City University; New Ross, Co. Wexford and Drogheda, Co. Louth were 46.5, 58.3 and 12.6 microg/L, respectively.

Acetates↗
PubMed2004

[Catalytic ozonation of trace nitrobenzene in water by iron hydroxide].

Laboratory produced iron hydroxide was tested for its activity in catalytic ozonation of trace nitrobenzene (NB) in water. The catalysis mechanism was deduced from the effect of tert-butanol on the reaction and the difference of catalytic activity between several typical transition metal oxides. Effects of catalyst dose, pH, bicarbonate ion, and times of catalyst reuse on NB removal were also examined. The iron hydroxide showed high catalytic activity on ozonation of NB with removal rate of NB dissolved in distilled water increased by 44.8% at reaction time of 20min. The catalysis follows a hydroxyl radical pathway and is affected by density of hydroxyl groups on the oxide. An optimal catalyst dosage of 100mg/L existed in this experiment. Solution pH near pH of zero charged surface of the oxide favored NB removal and bicarbonate concentration of 2.38mmol/L significantly reduced it. The oxide was used for five times with no significant change of its activity and no dissolution was observed.

Catalysis↗
PubMed2004

[Calcium hydroxide and treatment of inflammatory inter-radicular bone resorption of non-vital deciduous molars].

On non-vital deciduous molars, inter-radicular bone resorption is often an indication of extraction. The endodontic treatment of these teeth by means of zinc oxide-eugenol (ZOE) paste also showed its limits. To mitigate the deficiencies of this material, we suggested a preliminary treatment by means of calcium hydroxide (Ca(OH)2) for its anti-inflammatory and antiseptic properties as well as its ability to stimulate calcified tissues apposition or remineralisation. This study concerns 21 non-vital deciduous molars. X-rays excluded any lesion of the underlying permanent bony crypt (bone tissue) as well as any inflammation of the dental follicle. After preparation, root canals were filled by means of Pulpdent. An initial X-ray check was made 15 days and then every 3 months. After disappearance of the inflammatory resorption, root canal fillings were performed with ZOE paste. The remineralisation of the inter-radicular alveolar bone was observed for 14 deciduous molars, which were then filled using ZOE. The remineralisation period varies from 3 to 18 months depending on the scale of the lesion. Of the 7 failed treatments, 3 failed following downfall of the crown filling material, and 2 due to failure to keep appointments and late replacement of resorbed Ca(OH)2. On 2 teeth, the treatment did not stop the lesion forming. Calcium hydroxide (Ca(OH)2) give encouraging results in the treatment of inter-radicular alveolar bone resorption of non-vital deciduous tooth. Its fast resorption requires rigorous controls, frequent refills, and thus strong motivation on the part of the child and parents. It cannot, on any account, be considered as permanent filling material.

Alveolar Bone Loss↗
PubMed2004

Chemical injury to the tongue following contact with sodium hydroxide drain cleaner.

Solid sodium hydroxide compounds are used to unclog drains. In Turkey, these agents are easily available and commonly used by housewives. They are sold in weak bags and usually stored within these bags. We present the case of an elderly woman with dementia who developed severe alkaline tongue burn and edema after unintentional short contact with solid sodium hydroxide drain cleaner. Official legislation for safety packing in Turkey will lead to reduction in the incidence of accidental caustic injuries.

Aged↗
PubMed2004

Selected cases of periapical changes treated with calcium hydroxide preparations.

Success in endodontic treatment with application of non-hardening calcium hydroxide preparations to periapical pathosis has been described. The clinical procedures consisted in elaboration of root canals and temporary filling with Biopulp preparation. Control clinical and radiological investigations were carried out after 3 and 6 months. In spite of occurrence of initial periapical pathosis, the method of treatment with calcium hydroxide preparations permitted to achive positive results of healing of periapical pathosis thus eliminating the necessity of surgical operation.

Adult↗
PubMed2005

Apexogenesis of a symptomatic mandibular first permanent molar with calcium hydroxide pulpotomy.

Vital pulp therapy of immature, symptomatic permanent posterior teeth presents a challenge in pediatric endodontics. A case report is presented in which cervical pulpotomy with calcium hydroxide was performed on a cariously exposed mandibular first permanent molar. The patient was seen every 3 months for a total of 18 months for a clinical and radiographic follow up. During the follow-up period, root development, as evidenced by root lengthening, was observed. Apical closure was evident at the end of 19 months. As the root canals showed a tendency toward calcification, root canal treatment was carried out, followed by restoration of the tooth with a stainless-steel crown. The success of this single-visit apexogenesis procedure supports the contention that young pulp possesses remarkable reparative capacity, as well as resistance to bacterial infection due to greater vascularity, and that apexogenesis with calcium hydroxide apical closure pulpotomy can be attempted for continued root development of symptomatic, vital, permanent teeth.

Calcium Hydroxide↗
PubMed2005

Antimicrobial effect in vitro of chlorhexidine and calcium hydroxide impregnated gutta-percha points.

UNLABELLED: The aim of this study was to evaluate the antimicrobial activity of points containing antiseptics used for temporary obturation in endodontics. Points containing calcium hydroxide (Roeko and Hygienic), and chlorhexidine (Roeko) were tested and gutta-percha points served as control (Meta Dental Corp.). The following microorganisms were studied: Streptococcus mutans (Sm), Enterococcus faecalis (Ef), Staphylococcus aureus (Sta), Candida albicans (Ca), Fusobacterium nucleatum (Fn) ATCC 25586, Porphyromonas gingivalis (Pg) ATCC 33277, and Prevotella intermedia (Pi) ATCC 25611. The experiments were organized in three stages: 1st stage: one point of each kind was placed on agar plates previously seeded with microorganisms. 2nd stage: Another group of points was immersed in broth for 24 hours and placed on the seeded agar. Samples were then incubated at 37 degrees in the conditions of oxygen and for the time required by each microorganism. The zones of bacterial inhibition around each point were measured. The pH values of the broths were recorded. 3rd stage: the immersion broths were inoculated with suspensions of microorganisms, incubated, seeded on plates by dissemination and incubated. CFU counts were performed. RESULTS: points containing chlorhexidine showed inhibition zones with every microorganism in the 1st stage and, in the 2nd stage, with most of the microorganisms studied, except for Fn and Pi. Calcium hydroxide containing points did not inhibit any of the microorganisms assessed. Broth pH values did not exhibit any changes. CFU counts of the broths in which chlorhexidine points had been immersed showed total inhibition for all the microorganisms. The differences between materials were statistically significant (p<0.05) (ANOVA). In the conditions of this study, chlorhexidine-containing points proved to be effective against most of the tested strains.

Anti-Infective Agents, Local↗
PubMed2005

[Comparison of calcium hydroxide and chlorhexidine as intracanal medications in endodontics: review of the literature].

Calcium hydroxide has found its use in endodontic treatments. On the other hand, chlorhexidine is more and more proposedfor uses in clinical endodontics. Could chlorhexidine surpass calcium hydroxide and what are the benefits of chlorhexidine? This literature overview concludes that both medications are useful and that further studies are necessary before chosing one above the other.

Bacteria↗
PubMedDate not supplied

Clinical and radiographic evaluation of pulpotomies employing calcium hydroxide and trioxide mineral aggregate.

This study utilized clinical and radiographic examinations to compare the effectiveness of calcium hydroxide paste and mineral trioxide aggregate (MTA) for pulpotomies of primary molars in children. Ninety primary molars that showed clinical and radiographic indications for pulpotomy treatment were selected. The pulpotomies were performed in two sessions, using a corticosteroid/antibiotic solution as therapeutic dressing. The sample was divided into two groups of 45 teeth, in which the pulpal remains were protected with either calcium hydroxide paste (Group 1) or MTA (Group 2). Radiographs were taken immediately and at 3-, 6-, and 12-month follow-up appointments. Three teeth in Group 1 failed after three months, while two cases failed after six months and one more failed at one year. Two failures were found in Group 2 at the 12-month follow-up. These results indicate that both materials may be utilized for pulpotomies in primary teeth.

Aluminum Compounds↗
PubMedDate not supplied

Comparison of mineral trioxide aggregate and calcium hydroxide as pulpotomy agents in young permanent teeth (apexogenesis).

PURPOSE: The purpose of this study was to compare mineral trioxide aggregate (MTA) with calcium hydroxide (Ca(OH)2) clinically and radiographically as a pulpotomy agent in immature permanent teeth (apexogenesis). METHODS: Fifteen children, each with at least 2 immature permanent teeth requiring pulpotomy (apexogenesis), were selected for this study. All selected teeth were evenly divided into 2 test groups. In group 1, the conventional Ca(OH)2pulpotomy (control) was performed, whereas in group 2, the MTA pulpotomy (experimental) was done. The children were recalled for clinical and radiographic evaluations after 3, 6, and 12 months. RESULTS: The follow-up evaluations revealed failure due to pain and swelling detected at 6 and 12 months postoperative evaluations in only 2 teeth treated with Ca(OH)2. The remaining 28 teeth appeared to be clinically and radiographically successful 12 months postoperatively. Calcific metamorphosis was a radiographic finding in 2 teeth treated with Ca(OH)2 and 4 teeth treated with MTA. CONCLUSIONS: Mineral trioxide aggregate showed clinical and radiographic success as a pulpotomy agent in immature permanent teeth (apexogenesis) and seems to be a suitable alternative to calcium hydroxide.

Aluminum Compounds↗