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PubMed1990

Adaptation of two different calcium hydroxide bases under a composite restoration.

A preliminary scanning electron microscope (SEM) study was carried out to investigate how the adaptation of two calcium hydroxide bases (one chemically cured, one light cured) was affected by the polymerization contraction of a supervening light-cured composite resin restoration. Occlusal cavities were prepared in 40 sound extracted human premolars, divided into two equal groups. In the first group a chemically cured calcium hydroxide (Dycal, De Trey Dentsply, Konstanz, FRG) was placed as a base. In the second group a new light-cured calcium hydroxide product (Prisma VLC Dycal, De Trey Dentsply) was used. The restorations were completed with an acid-etched, incrementally placed composite resin. The specimens were sectioned vertically and debrided. A replica was made of each half-tooth. The interfaces between composite resin/base and base/dentine were viewed and photographed in the SEM. The marginal adaptation at these two interfaces was classified into three categories according to the extent of the gaps that were observed. Prisma VLC Dycal base was found to be pulled away from the dentine floor of the cavity as a result of an apparent adhesion to the composite resin during polymerization contraction. Dycal was better adapted to the cavity floor than Prisma VLC Dycal. Disorganization of the resin-bonded Prisma VLC Dycal was minimal even after acid etching the enamel, sectioning and ultrasonic debridement. Dycal appeared to be more friable, and occasionally exhibited marked disorganization as a result of these procedures.

Acid Etching, Dental↗
PubMed2004

Evaluation of disinfected casts poured in gypsum with gum arabic and calcium hydroxide additives.

STATEMENT OF PROBLEM: Disinfection of stone casts is an important measure for the control of cross-contamination. Many approaches have been used to disinfect stone casts, but information regarding the accuracy of the resultant casts is limited. PURPOSE: The purpose of this in vitro study was to evaluate the dimensional accuracy, incidence of abutment fracture, and the abutment reproduction of disinfected stone casts made from elastomeric impressions and to determine the effect of gum arabic and calcium hydroxide additives on these properties. MATERIAL AND METHODS: Two aqueous solutions of chemical disinfectants (0.525% sodium hypochlorite and 0.1% povidone iodine) were used as mixing water substitutes for 3 types of dental stone: Types III (Lab Stone), IV (Mile Stone), and V (Die Keen). These stone powders were subjected to further modification by adding 1% gum arabic and 0.132% calcium hydroxide before mixing at the manufacturer-recommended liquid/powder ratios (0.30 for Type III, 0.21 for Types IV and V, respectively). As these additives increased the fluidity of the mix, reduced liquid/powder ratios (0.26 for Type III, 0.19 for Types IV and V, respectively) were also evaluated. Unmodified stone powder mixed with water served as the control. These modifications resulted in 7 test groups for each type of stone. Mixed stones of these groups were poured into 10 putty/wash vinyl polysiloxane impressions made of a customized definitive cast. The percentage of abutments fractured at the time of releasing the resultant casts, as well as the percentages of incompletely reproduced abutments, abutments with air bubbles, and abutments with defective finish lines were compared statistically among the tested groups using the chi-square test (alpha=.05). The average dimensional deviations of the resultant cast from the definitive cast measured in mm were statistically analyzed using 1-way ANOVA (alpha=.05) followed by the Dunnett test to detect any differences among the tested groups. RESULTS: No significant difference was found in abutment fracture or abutment defects for the different formulations of each type of stone used. The resultant casts showed no significant dimensional changes except for Type III and IV stones modified by gum arabic and calcium hydroxide additives and mixed at the recommended liquid/powder ratios. CONCLUSION: Both 0.525% sodium hypochlorite and 0.1% povidone iodine can be used to disinfect dental gypsum with no significant effect on the dimensional accuracy and reproducibility of the resultant casts. Addition of gum arabic and calcium hydroxide to the hemihydrate powders before mixing does not aid in reducing the incidence of defective abutment reproduction.

Analysis of Variance↗
PubMed2004

Comparative evaluation of lyophilized freeze dried platelet derived preparation with calcium hydroxide as pulpotomy agents in primary molars.

The aim of this study was to compare the efficacy of lyophilized freeze dried platelet derived preparation with calcium hydroxide as pulpotomy agents in primary molars. Fifty six primary molars in 28 children were treated by a conventional pulpotomy technique. 28 teeth were treated by lyophilized freeze-dried platelet derived preparation and another 28 by calcium hydroxide. Clinical evaluation was carried out out at 1, 3, and 6-months interval and the radiographic evaluation was carried out at 1 and 6-months. The success rate of lyophilized freeze-dried platelet derived preparation proved better than calcium hydroxide.

Blood Platelets↗
PubMed2000

Influence of calcium hydroxide intracanal dressings on the prognosis of teeth with endodontically induced periapical lesions.

AIM: This prospective clinical study explored the influence of calcium hydroxide as an interappointment dressing on the healing of periapical lesions associated with pulpless teeth that had not been endodontically treated previously. This was achieved by comparing the prognosis after a two-visit root canal treatment with that following a one-visit treatment. METHODOLOGY: Seventy-three patients were recruited having one tooth with an endodontically induced lesion. Of these patients, 67 could be re-examined. Calcium hydroxide was placed in the instrumented root canals of 31 teeth for at least one week and the treatment finished at the second visit. Thirty-six teeth were root canal treated at one visit. The criteria for success were the absence of signs and symptoms indicating an acute phase of periapical periodontitis and radiographically a periodontal ligament space of normal width. Methods for event time analysis were used to evaluate and compare the prognosis of both treatment approaches. RESULTS: The probability that complete periapical healing will take place increased continuously with the length of the observation period. In both treatment groups the likelihood that the root canal treatment yields a success within an observation time of five years exceeded 90%. A statistically significant difference between the two treatment groups could not be detected. CONCLUSIONS: From a microbiological perspective, one-visit root canal treatment created favourable environmental conditions for periapical repair similar to the two-visit therapy when calcium hydroxide was used as antimicrobial dressing. One-visit root canal treatment is an acceptable alternative to two-visit treatment for pulpless teeth associated with an endodontically induced lesion.

Adolescent↗
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↗
PubMed2000

A comparison of the surface tension of calcium hydroxide mixed with different vehicles.

The aim of this study was to evaluate and compare the surface tension of different liquids that are used as potential agents to mix with calcium hydroxide in root canal treatment. We also tried to evaluate final surface tension values of the calcium hydroxide mixed with glycerin, Ringer's solution, anesthetic solution, and saline. Surface tension values were measured using a "Du Noüy" tensiometer. The results showed statistically significant differences between vehicles alone and the calcium hydroxide combinations and also indicated that anesthetic solution (p = 0.018, p < or = 0.02) is the most favorable vehicle with the lowest surface tension values.

Analysis of Variance↗
PubMed2007

Calcium hydroxide barrier over the apical root-end of a type III dens invaginatus after endodontic and surgical treatment.

AIM: To report the simultaneous endodontic and surgical treatment of a tooth associated with Oehlers type III dens invaginatus and a persistent periapical lesion, which comprised root-end resection, root-end filling and application of a calcium hydroxide barrier placed on the resected dentine surface. SUMMARY: Three root canals were identified in a tooth with a type III dens invaginatus, which presented with a necrotic pulp, wide foraminal opening and extensive periapical lesion, and with a previous history of acute abscess, intracanal exudate and fistula. After root canal preparation followed by intracanal application of calcium hydroxide pastes, the clinical-pathological status persisted. After periapical curettage and root-end resection, the root canals were filled, followed by root-end filling with Sealer 26 mixed with zinc oxide powder to a clay-like consistency. Calcium hydroxide paste was then applied over the exposed dentinal surface forming a covering over the root apex. At the 20-month follow-up examination the patient had no symptoms and no fistula; advanced periapical bone repair was obvious on the radiograph. KEY LEARNING POINTS: Because of the variable morphology and extent of invagination, type III dens invaginatus represents a challenge for conventional treatment, often leading to the need for a surgical approach. Sealer 26 thickened with zinc oxide powder provided satisfactory clinical properties for use as a root-end filling material. Application of a calcium hydroxide barrier over the resected root-end is a potential treatment option to encourage tissue repair.

Adolescent↗
PubMed1991

Erosion process of calcium hydroxide cements in water.

Erosion process of calcium hydroxide cements was examined for 7 days by chemical analysis of eluates and observation of structural change of the eroded cements when the cements were immersed in water at 37 degrees C. The elution of salicylate from the set cements as well as that of Ca continued during the immersion time. In the early stage of the erosion, unreacted Ca(OH)2 was preferentially extracted from the cements in comparison with Ca-alkyl salicylate chelate of the cement matrix. The elution rate of N-ethyl o- and p-toluene sulphonamides, which were contained as plasticizer, was higher than those of Ca and salicylate. Insoluble inorganic filler remained at the surface of the cements after extraction of unreacted Ca(OH)2 and disintegration of the cement matrix. Types of salicylate ester seemed to affect the cement durability.

Calcium Hydroxide↗
PubMed2004

Evaluation of pH levels and calcium ion release in various calcium hydroxide endodontic dressings.

OBJECTIVE: The purpose of this study was to evaluate Ca(2+) release and pH of 3 calcium hydroxide-based products used routinely as intracanal dressings, as well as the new gutta-percha points with calcium hydroxide. STUDY DESIGN: The pH and Ca(2+) release were assessed using Calen with camphorated paramonochlorophenol, saline calcium hydroxide paste, LC paste (Lopes and Costa paste-calcium hydroxide with olive oil), and calcium hydroxide containing gutta-percha points. The materials were inserted in polyethylene tubes and immersed in deionized water. The pH variation and Ca(2+) release were monitored periodically for 4 weeks. RESULTS: After 72 hours, materials 1 and 2 raise the pH from 9.6 and 8.2 to 11.4 and 11.3, respectively, while a small change was observed for materials 3 and 4. The calcium concentration released from materials 1, 2, 3, and 4 after 72 hours was 6.54, 4.98, 1.31, and 1.74 mg/dL, respectively. CONCLUSION: Calen plus camphorated paramonochlorophenol and saline calcium hydroxide paste exhibited the highest calcium release and pH levels.

Analysis of Variance↗
PubMed2000

The influence of sample dimensions on hydroxyl ion release from calcium hydroxide products.

The purpose of this study was to compare the rate of hydroxyl ion release from commercially available setting and non-setting calcium hydroxide products. The rate of hydroxyl ion release is important, as this has been suggested to be the main factor in the therapeutic activity of these products. In total, hydroxyl ion release was measured from 1104 samples of Dycal, Life, Calasept and Hypocal in solution using in vitro titration. The rate of hydroxyl ion release was measured for up to 14 days, using two sizes of sample surface area. The dimensions of the exposed sample surface area was found to be an important physical constraint to the hydroxyl ion release from non-setting calcium hydroxide products, whereas this was not found to be the case with setting products. The range in hydroxide activity between products was found to be 298%. In rank order of hydroxide ion release, from the most to the least active was: Hypocal, Calasept, Life and Dycal. The differences in the rate of hydroxyl ion release from these products may have some implications for their clinical applications. It is suggested that in cases where the oral healing responses have been poorer than expected, the size and seal of prepared cavities could have negatively influenced the therapeutic release of hydroxyl ions from non-setting calcium hydroxide products.

Analysis of Variance↗
PubMed1993

In vitro antimicrobial activity of calcium hydroxide cements on Streptococcus sanguis NCTC 7864.

Several studies have questioned the antimicrobial role of calcium hydroxide cements. This study assessed the antimicrobial activity of four commercially available calcium hydroxide cements on Streptococcus sanguis NCTC 7864 using inoculated Mueller-Hinton growth medium. Growth curves from optical density analysis, pH measurements, and viability counts were compared over a 24 h period. Significant differences occurred (P < 0.05) between pH measurements but not the growth curves or the viability counts. All cements exerted a cidal effect although this cannot be attributed to an increase in alkalinity alone.

Analysis of Variance↗
PubMedDate not supplied

[Antibacterial action of calcium hydroxide as a root canal medicament].

In this review article the antibacterial action of calcium hydroxide, as a root canal medicament is discussed. Initially its physicochemical principles as hydroscopic action, pH, gas absorption, ionism energy, etc., are described. Finally the antimicrobial effect of calcium hydroxide is correlated to the above properties.

Calcium Hydroxide↗
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↗
PubMedDate not supplied

Flare-ups incidence and severity after using calcium hydroxide as intracanal dressing.

Acute pain and swelling following endodontic treatment are a challenge for both the patient and the dentist. According to previous studies, the incidence of flare-ups increases after endodontic treatment of teeth with necrotic pulps. Calcium hydroxide is currently used as a multi-purpose drug in root canal therapy. The aim of this study was to evaluate the incidence and severity of flare-ups after treatment of pulpless teeth using calcium hydroxide as an intracanal dressing. Sixty patients with single-root necrotic teeth participated in this study. These patients were randomly divided into three groups of 20. The patients were treated in Group A in a single-visit approach, in group B with a two-visit approach without any intracanal dressing and group C with a two-visit approach using calcium hydroxide as an intracanal dressing for one week. All of the patients were followed for 72 hours after each treatment session. The information about the incidence and severity of pain and swelling was recorded in tables, using a modified Visual Analogue Scale for pain severity measurement and a scale with four degrees for measuring the severity of swelling. The data were analyzed by chi-square test and GENMODE procedure.

Calcium Hydroxide↗
PubMed2005

Endodontic therapy associated with calcium hydroxide as an intracanal dressing: microbiologic evaluation by the checkerboard DNA-DNA hybridization technique.

This study evaluated the predominant microbiota of infected necrotic pulps and the effects of calcium hydroxide therapy on these microorganisms by the checkerboard DNA-DNA hybridization technique. Conventional endodontic therapy associated with calcium hydroxide as intracanal dressing was performed in 12 single-rooted teeth with pulp necrosis and periradicular bone lesion. Samples were collected from the canal at baseline and 14 days after therapy, and the presence of 44 bacterial species was determined by the checkerboard method. Significant differences in the microbiota from baseline to post-therapy were sought by the paired-samples t test. The most prevalent species included F. nucleatum ss. vincentii, C. sputigena, C. ochracea, S. constellatus, V. parvula, P. gingivalis, P. melaninogenica, and S. sanguis. Most of the microorganisms were reduced after treatment, particularly A. gerencseriae, A. israelii, A. naeslundii, C. gingivalis, C. ochracea, P. gingivalis, S. noxia, S. sanguis, and S. oralis (p < 0.05). Conversely, A. actinomycetemcomitans, C. sputigena, and E. corrodens increased in numbers after therapy. These results indicate that conventional endodontic therapy with calcium hydroxide results in the reduction of pathogenic species associated with pulp necrosis. However, its use is limited, because it did not eliminate the whole spectrum of microorganisms.

Adult↗
PubMed2005

Calcium hydroxide dressings using different preparation and application modes: density and dissolution by simulated tissue pressure.

AIM: To study the effect of different apical shapes in prepared simulated root canals on the application of a commercially prepared calcium hydroxide paste by a syringe or lentulo spiral. METHODOLOGY: Three different types of root canal preparation were performed in 90 simulated canals: group A to an apical size 20 and a 0.10 taper using hand and rotary instruments, group B to an apical size 30 and a 0.08 taper using GT rotary instruments and group C to an apical size 40 and a 0.04 taper using ProFile 0.04 instruments. The insertion of calcium hydroxide [Ca(OH)2] paste was accomplished using either a lentulo spiral or a syringe. After 1 week of simulated fluid pressure applied to the apical end of the canal using physiological saline solution, the solution was evaluated for released Ca(OH)2. The specimens were weighed initially, after preparation, after insertion of Ca(OH)2 paste, after temporization with Cavit and after 1 week of simulated fluid pressure. Digital radiographs of the filled canals were taken and canal areas in mm2, gray values of the Ca(OH)2 dressings, total area of voids in mm2, as well as location of voids in the apical, middle or coronal thirds of the root canals were measured. Analyses of variance, with Scheffe's post-hoc tests, as well as chi-square tests were performed. RESULTS: Canals in group C had significantly fewer (P < 0.01) radiographic voids than canals in groups A and B. Using a lentulo spiral resulted in significantly (P < 0.05) fewer voids compared with the injection technique. More voids were detected coronally compared with middle and apical root canal thirds (P < 0.05). CONCLUSIONS: Canal shape and method of application had an impact on the amount and radiodensity of calcium hydroxide dressings in simulated root canals. Canals prepared to an apical size 40 and a taper of 0.04 had the least number of voids; Ca(OH)2 was placed with significantly fewer voids using a lentulo spiral compared with the injection technique.

Calcium Hydroxide↗
PubMedDate not supplied

Histologic evaluation of pulpotomy performed with ethyl-cyanoacrylate and calcium hydroxide.

The aim of this study was to evaluate histological aspects of the pulp-dentin complex of dogs submitted to pulpotomy and capped with ethyl-cyanoacrylate and calcium hydroxide. Thirty dog teeth were divided into 2 groups of 15 as follows: Group 1 - ethyl-cyanoacrylate; Group 2 - calcium hydroxide. The pulpotomies were carried out following all of the treatment precautions recommended for dogs. After 30 days the specimens were submitted to histological preparation and were then blindly evaluated by a histologist. Data were analyzed statistically by the Fisher exact test, comparing the two groups. After 30 days, the presence of a hard tissue barrier was observed in 83.3% of Group 1, and in 100% of Group 2 (p = 0.478). A continuous hard tissue barrier was observed in 50% of the ethyl-cyanoacrylate group and 75% of the calcium hydroxide group (p = 0.652). It can be concluded that both materials induced hard tissue barrier formation, but Group 2 had a higher percentage than Group 1, with no significant statistical differences; the differences observed between the different barriers (continuous/non-continuous) were not significant between groups and there was no pulpal necrosis in either group.

Animals↗