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PubMed2004

The effect of two different calcium hydroxide combinations on root dentine microhardness.

AIM: To evaluate the effect of a calcium hydroxide and glycerine mix and a calcium hydroxide and water mix on the microhardness of human root dentine. METHODOLOGY: Eleven freshly extracted maxillary canine and central incisor teeth were used. The teeth were sectioned transversally to produce a total of 22 dentine discs from the middle-third of the root. The specimens were divided into two groups of 11 discs each. Dentine samples were treated with either a Ca(OH)2-glycerine combination or a Ca(OH)2-distilled water combination for 1, 3 and 7 days. Dentine microhardness was measured with a Knoop indenter with a load of 100 g for 15 s before and during the experimental period. Each root disc received a series of three indentations around the pulp space, 1 mm from canal wall. RESULTS: Statistical analysis showed that both combinations significantly decreased dentine microhardness after 3 and 7 days (P < 0.01). The reduction in dentine microhardness following the use of a Ca(OH)2-glycerine combination was significantly greater than that after a Ca(OH)2-distilled water combination after 3 and 7 days (P < 0.01). CONCLUSION: The use of Ca(OH)2 combinations for intracanal dressing softens dentine.

Calcium Hydroxide↗
PubMed2007

Antibacterial efficacy of calcium hydroxide intracanal dressing: a systematic review and meta-analysis.

AIM: To determine to what extent does calcium hydroxide intracanal medication eliminate bacteria from human root canals, compared with the same canals before medication, as measured by the number of positive cultures, in patients undergoing root canal treatment for apical periodontitis (teeth with an infected root canal system). METHODOLOGY: CENTRAL, MEDLINE and EMBASE databases were searched. Reference lists from identified articles were scanned. A forward search was undertaken on the authors of the identified articles. Papers that had cited these articles were also identified through the Science Citation Index to identify potentially relevant subsequent primary research. REVIEW METHODS: The included studies were pre-/post-test clinical trials comparing the number of positive bacterial cultures from treated canals. Data in those studies were independently extracted. Risk differences of included studies were combined using the generic inverse variance and random effect method. RESULTS: Eight studies were identified and included in the review, covering 257 cases. Sample size varied from 18 to 60 cases; six studies demonstrated a statistically significant difference between pre- and post-medicated canals, whilst two did not. There was considerable heterogeneity among studies. Pooled risk difference was -21%; 95% CI: -47% to 6%. The difference between pre- and post-medication was not statistically significant (P = 0.12). CONCLUSIONS: Calcium hydroxide has limited effectiveness in eliminating bacteria from human root canal when assessed by culture techniques.

Bacteria↗
PubMed1995

The rate of OH- ion release from lining materials containing calcium hydroxide.

Four light-cured calcium hydroxide and three chemically cured resin-based lining materials were compared for hydoxil ion (OH-) release. Results indicated that the chemically cured calcium hydroxide cements were capable of OH- release for a longer period than the light-cured resin bases. Alkaliner (a chemically cured liner) produced and maintained the highest alkaline environment in the long-term, whereas calcium fluoride liner and Basic-L (both resin-based) showed the lowest values of OH- ion release.

Analysis of Variance↗
PubMed1985

Aluminium hydroxide adsorbed allergens used in modified RAST.

A method is described in which the conventional radioallergosorbent test (RAST) for determination of allergen-specific IgE in serum has been modified by displacing the solidphase sorbent by a gel of aluminium hydroxide (Al(OH)3). The optimum conditions for this new analysis (AlRAST) are determined, taking into account speed, costs and the ratio between responses of patients and normal individuals. The AlRAST fulfills the criteria for validity: it is specific and shows parallelism between serum dilution curves. The sensitivity and reproducibility are slightly lower than in the conventional RAST, but sufficient for most routine and screening procedures. The preparation of allergosorbents in AlRAST can be accomplished within 1 h, thus making it convenient for fast screening of patients against unusual allergen extracts, as well as for allergen standardization from dose-response curves. Further, it is possible to standardize aluminium hydroxide adsorbed extracts used for immunotherapy by using the products directly as allergosorbents in the AlRAST.

Allergens↗
PubMed1998

Double-blind, placebo-controlled study of magnesium hydroxide for treatment of sensory urgency and detrusor instability: preliminary results.

In a prospective, randomised, double-blind, placebo-controlled study 40 women with sensory urgency or detrusor instability randomly received either magnesium hydroxide (group A) or placebo (group B). Pre- and post-treatment symptoms, frequency-volume charts and cystometry results were compared. Eleven of 20 patients receiving magnesium (55%) reported a subjective improvement of their urinary symptoms, compared with five patients taking placebo (20%). In both study groups there was no statistically significant difference in pre- and post-treatment urodynamic parameters in those reporting symptomatic improvement. Magnesium was well tolerated by patients in group A, and no side effects were reported. These results suggest that magnesium hydroxide may be beneficial for detrusor instability or sensory urgency in women.

Dose-Response Relationship, Drug↗
PubMed1998

Effect of magnesium hydroxide on iron absorption following simulated mild iron overdose in human subjects.

OBJECTIVE: To determine the effect of oral magnesium hydroxide [Mg(OH)2] on iron absorption after simulated iron overdose in human subjects. METHODS: A randomized, controlled crossover study was conducted in healthy adult male human volunteers taking no medications. Subjects received an average of 5.0 mg/kg elemental iron orally followed 1 hour later by either oral administration of 4.5 g of Mg(OH)2 per g ingested elemental iron or no treatment. Serial serum specimens were obtained over the 12 hours following iron ingestion and stored at -60 degrees C until standard serum iron assay was performed. After a 2-week washout period, the subjects were enrolled in the alternative trial arm. Individual baseline diurnal variation in serum iron levels was determined over a 12-hour period on the day prior to each trial. Area under time-concentration curves (AUCs) were calculated, and the AUC due to experimental iron ingestion (deltaAUC) was determined by subtracting the baseline diurnal AUC from the experimental AUC for each subject. RESULTS: Thirteen healthy adult male subjects were enrolled. Mean +/- SEM for deltaAUC due to experimental iron ingestion followed by treatment with Mg(OH)2, 78 +/- 23 micromol(hr)/L, was significantly less than that followed by no treatment, 144 +/- 33 micromol(hr)/L (p = 0.03 by signed rank test). CONCLUSIONS: Magnesium hydroxide, administered 1 hour post-iron ingestion at an oral dose of 4.5 g per g elemental iron ingested, significantly reduced iron absorption during a 12-hour period following simulated mild iron overdose in healthy adult human volunteers.

Absorption↗
PubMed1992

Endodontic infection and calcium hydroxide-treatment. Effects on periodontal healing in mature and immature replanted monkey teeth.

Large experimental defects with marginal communication, and small isolated experimental defects were created on the root surfaces of extracted monkey lateral incisors with either open or closed apices. The pulp tissue was either infected or removed, and calcium hydroxide placed in the root canal. The teeth were then replanted and the healing pattern evaluated histomorphometrically after 20 weeks. From the results, it was concluded that (1) an intrapulpal infection promotes marginal epithelial down-growth on a denuded dentin surface irrespective of tooth developmental stage, and that (2) the periodontal healing potential after calcium hydroxide-treatment appears to be higher in teeth with open apices compared with teeth with closed apices, where ankylosis was promoted as opposed to teeth with open apices where significantly more reparative cementum was found.

Animals↗
PubMed1980

The response of four calcium hydroxides on monkey pulps.

Dentinal bridge formation and pulpal responses of four calcium hydroxide materials, pulp capping medicaments, MPC, Experimental MPC-12, Dycal and Pulpdent, were evaluated in primary and permanent monkey teeth. A total of 60 primary and 60 permanent teeth were used with each material placed in a Class V cavity exposure in Rhesus monkey teeth. The materials were placed on the exposed pulp tissue and were histologically evaluated at 3 days, 5 weeks and 8 weeks. After perfusion the teeth were processed using routine histological procedures. The 3-day pulpal responses in both primary and permanent teeth were moderate, characterized by disruption of the pulpal tissue directly beneath the exposure site and a zone of acute inflammation and hemorrhage in the underlying pulp. The 5-week response showed histological differences between the four medicaments, with Dycal producing the least amount of pulpal irritation with reparative dentin bridges occurring in 50% of the permanent teeth. Experimental MPC-12 stimulated one reparative dentin bridge, while Pulpdent and MPC showed no evidence of bridge formation. Pulpal responses to Dycal were moderate and moderate to severe for the other calcium hydroxide compounds. No reparative dentin bridges were seen in the primary teeth at 5 weeks with any of the materials, and the pulpal responses were of a moderate degree at that time. Eight-week responses were similar to the 5-week responses Dycal provoked a slight to moderate pulpal response with 50% success at bridging. Experimental MPC-12 initiated pulpal responses in the moderate to severe range with some bridging evident. Pulpdent incited moderate to severe histological responses with three teeth demonstrating bridge formation, and MPC provoked severe pulpal responses with no bridging. Primary teeth showed some bridging for all compounds except those treated with MPC, in which no evidence of bridging occurred, and moderate to severe pulpal responses were present.

Animals↗
PubMed1978

A 2-year follow-up of primary molars, pulpotomized with a gentle technique and capped with calcium hydroxide.

The prognosis for pulpotomy of primary molars with calcium hydroxide as wound dressing was evaluated clinically and radiographically. Thirty-three primary mandibular molars were amputated under the following conditions: (1) chronic coronal pulpitis, (2) the amputation was done with diamond instruments and a high-speed machine under aseptic conditions, and (3) application of calcium hydroxide in contact with the wound surface. After 1 year the treatment was regarded as successful for 22 of the teeth (67%); 11 teeth showed internal dentin resorption. After 2 years the frequency of success, allowing for drop-out, was 59%. Internal dentin resorption was seen in 14 root canals; in 10 of them within the first 6 months. A histologic study of nine root pulps with internal dentin resorption revealed an extra-pulpal blood clot on the wound surface in five.

Blood Coagulation↗
PubMed1989

In vivo sealing ability of calcium hydroxide-containing root canal sealers.

It was the purpose of this study to determine the sealing ability of 2 commercially available calcium hydroxide-containing root canal sealers, CRCS and Sealapex. One hundred sixty single-rooted human teeth were used. The clinical crowns were removed and the roots were cleaned mechanically and by immersion for 24 h in 5% sodium hypochlorite. The root canals were then instrumented to size 80 at the apical foramen and the roots were sterilized by gamma-radiation. Under aseptic conditions the root canals were filled with a gutta-percha master cone size 70 and Sealapex (48 roots), CRCS (48 roots), and a zinc oxide-eugenol type sealer, Roth 801 (50 roots). The coronal aspects of the root canals were then sealed with zinc oxide-eugenol cement. In order to bring the roots and root filling materials in contact with tissue and tissue fluids, the roots were implanted subcutaneously in rabbits for 90 days and 1 year. Leakage as demonstrated by penetration of India ink was evaluated using a stereomicroscope. The best results were obtained with CRCS. Significantly less leakage occurred with both calcium hydroxide-containing sealers than with the traditional zinc oxide-eugenol sealer.

Calcium Hydroxide↗
PubMed1989

Effects of combining Ledermix and calcium hydroxide pastes on the diffusion of corticosteroid and tetracycline through human tooth roots in vitro.

A 50:50 mixture of a corticosteroid/antibiotic paste and calcium hydroxide has been used clinically as a root canal dressing agent. This study investigated the effect on the release and diffusion of the corticosteroid and antibiotic components of Ledermix paste when it was mixed with a calcium hydroxide-methyl cellulose paste. The release rates of the trace molecules were lower when the mixture was used compared with release from Ledermix alone. The results indicated that this combination of materials, when used a long-term intracanal dressing, was likely to be more effective than Ledermix alone.

Calcium Hydroxide↗
PubMed1992

Prognosis of luxated non-vital maxillary incisors treated with calcium hydroxide and filled with gutta-percha. A retrospective clinical study.

A material of 885 luxated, non-vital incisors was evaluated radiographically with respect to healing of periodontal tissues including inflammatory root resorption and occurrence of ankylosis and cervical root fractures. The results were assessed after completion of calcium hydroxide treatment and 4 years after filling of the root canal with gutta-percha. After treatment with calcium hydroxide, periapical healing occurred in 95% of the teeth. Four years after filling with gutta-percha, periapical healing was present in 91% of the teeth. In the remaining teeth, recurrent or persistent periapical radiolucency was more frequent in overfilled than adequately filled teeth (P = 0.0001). There was no difference between immature and mature teeth. Inflammatory root resorption healed in 192 of 197 teeth (97%); in 5 teeth it developed into ankylosis. Ankylosis occurred in 13 teeth, all of which were intruded into the alveolar bone at the time of injury. The frequency of cervical root fractures was markedly higher in immature than mature teeth (P greater than 0.0001). Among immature teeth, the frequency of fractures was dependent on the stage of root development (chi 2 = 31.6) and ranged from 77% in teeth with the least to 28% in teeth with the most developed roots. The frequency of fractures was also related to the defects after healing of inflammatory root resorption in the cervical area of the root, significant at P less than 0.0001.

Calcium Hydroxide↗
PubMed1993

Bio-microscopical observation of dystrophic calcification induced by calcium hydroxide.

Calcium hydroxide paste was introduced into a rabbit ear chamber, and the effect of calcium hydroxide on the vascular tissue was observed under a bio-microscope continuously up to 14 weeks. Many precipitates were observed at the border of living tissue, after the dissolution of microvessels around the paste. They increased both in size and number to combine like a river bank in the first 48 h. After 1 week, microcirculation recovered, and newly-formed capillaries approached the precipitate-bank, the edge of which became smoother as weeks went by. The bank was stable and compatible to microvessels during the observation period. By SEM observation, the width of the bank was from 200 to 400 microns, and the tissue-side of the bank appeared like amorphous lamellae, while the inner-side showed particle-like appearance. EDX examination revealed high peaks of Ca and P similar to calcium phosphate at the tissue-side of the bank, but only Ca peak at the inner-side. The precipitates seemed to have the potential to induce dystrophic calcification by absorbing Ca and P from the tissue.

Animals↗
PubMed1993

In vitro evaluation of the effectiveness of calcium hydroxide and paramonochlorophenol on anaerobic bacteria from the root canal.

The effectiveness of calcium hydroxide and paramonochlorophenol (PMCP) was tested on anaerobic bacteria isolated from infected root canals, at time intervals 5, 15, 30 and 60 min. The experimental method used was similar to that proposed by the German Society of Hygiene and Microbiology (DGHM), with slight modifications. Testing revealed that calcium hydroxide was significantly more effective than PMCP against the total number of anaerobes. Additionally, it was proved to be quickly and highly effective against some microorganisms related to severe clinical symptoms, such as B. melaninogenicus and P. gingivalis, as well as against actinomyces species.

Actinomyces↗
PubMed1994

Evaluation of calcium hydroxide-containing root canal sealers with an improved rabbit ear chamber.

An improved rabbit ear chamber was used to evaluate calcium hydroxide-containing root canal sealers on their potential to induce dystrophic calcification in connective tissue. Four sealers and two control materials were introduced into the chambers and the effects of these materials on the living vascular tissue were observed continuously under a biomicroscope up to 9 weeks. Conventional histopathological investigation and examinations with a scanning electron microscope and an X-ray microanalyzer were done to supplement the results. Sealapex and Calvital (Ca(OH)2 + iodoform) revealed almost the same tissue reaction as calcium hydroxide-saline paste; they rapidly made a precipitate-barrier of calcium phosphate in the connective tissue, inducing calcification. However, Dentalis KEZ (ZnO-Ca(OH)2 + eugenol) caused mild disorders of microcirculation without calcification, as well as Canals (ZnO + eugenol). New A (Ca(OH)2 + fatty acid) had good compatibility with microvessels as well as New B (ZnO + fatty acid), however they induced no calcification and disintegrated rapidly in the tissue. These sealers were reclassified according to what they actually bring about in the tissue, not according to what they include.

Animals↗
PubMed1996

Endodontic treatment of teeth with apical periodontitis using calcium hydroxide: a long-term study.

The aim of this study was to evaluate clinically and radiographically the long-term results of endodontic therapy. A total of 172 mature teeth with periapical radiolucencies with and without symptoms were treated endodontically using calcium hydroxide paste as the intracanal medicament and a calcium hydroxide containing root canal sealer. In 58 teeth, the dressing was accidentally or intentionally extruded into the lesions. All cases were followed up for a period of 2-5 years. The teeth in which the dressing was extruded did not show a different healing pattern from the ones treated conventionally. The complete healing rate for all cases was 80.8% while incomplete healing had taken place in 7.6% of the cases.

Adolescent↗
PubMed1997

Comparative in vitro investigation of different methods for temporary root canal filling with aqueous suspensions of calcium hydroxide.

Three methods for temporarily filling root canals with calcium hydroxide pastes were compared. Each of 20 root canals of extracted, human, single-rooted teeth was shaped with hand instruments under standardized conditions up to ISO size 50 and filled using a syringe system, a lentulo spiral or an endodontic reamer. Quality of fillings was assessed radiographically and by inspecting ground preparations. Ridit (relative to an identified distribution) analysis was employed to confirm differences in frequencies of certain quality criteria obtained with various application methods. With regard to degree of obturation and occurrence of porosities, application of temporary fillings with a lentulo spiral or syringe system revealed significantly better results than application with hand instruments (reamer). No differences with regard to degree of obturation were detected when comparing results obtained with syringe or lentulo. Fewer porosities in the apical part of the root canal were seen, both on radiographs and ground sections, with the syringe system compared with the lentulo spiral. In the presence of some contradictory reports found in the literature, the present study suggests that, after straight or slightly curved root canals have been shaped up to at least ISO size 50, high quality temporary root canal fillings may be obtained by application of an aqueous suspension of calcium hydroxide with a syringe system.

Calcium Hydroxide↗
PubMed2004

Molecular evaluation of residual endodontic microorganisms after instrumentation, irrigation and medication with either calcium hydroxide or Septomixine.

BACKGROUND AND OBJECTIVE: The correct choice of antimicrobial agents as inter-appointment medicaments is as important as the instrumentation and irrigation to remove pathogens from infected root canals. Calcium hydroxide [Ca(OH)2] and framycetin sulfate (Septomixine) are common endodontic medicaments. Therefore, we evaluated the efficacy of either calcium hydroxide or Septomixine in eliminating residual intra-canal bacteria, particularly Actinomyces spp., during inter-appointment interval in endodontic therapy using molecular methods. METHODS: A total of 31 single-rooted teeth with primary root canal infections were studied immediately after opening the canals and subsequently after instrumentation, irrigation with sterile saline and 1-week medication with either Ca(OH)2 (n = 25) or Septomixine (n = 6). Whole bacterial genomic DNA was isolated directly from samples and PCR with universal primers performed to detect total intra-canal bacteria. The variable regions of 16S rDNA of bacteria were amplified and labeled with digoxigenin for further hybridization to detect Actinomyces spp. A total of seven oligonucleotide probes specific for A. bovis, A. gerencseriae, A. israelii, A. meyeri, catalase-negative A. naeslundii (genospecies 1 and 2), catalase-positive A. naeslundii genospecies 2 and A. odontolyticus were used to detect Actinomyces spp. in 22 of 31 medicated root canals [Ca(OH)2: n = 17; Septomixine: n = 5]. RESULTS: The PCR results showed that 25 of 31 examined canals were positively detected with residual microorganisms after instrumentation, irrigation with sterile saline and 1-week medication with either Ca(OH)2 (n = 20) or Septomixine (n = 5). Thus, only six canals [Ca(OH)2: n = 5, Septomixine: n = 1] were aseptic after treatment. Hybridization results showed higher detection frequency of both A. odontolyticus and A. gerencseriae after treatment. Significant correlation was found between exposed pulp before treatment and positive detection of Actinomyces spp., particularly A. odontolyticus on the second visit (P < 0.05). CONCLUSION: The conventional, 1-week medication of either Ca(OH)2 or Septomixine in endodontic therapy may not effectively inhibit residual bacterial growth in all root canals during inter-appointment intervals. Further investigations using, for instance quantitative real-time PCR analyses, are required to substantiate the present findings.

Actinomycosis↗