Placement Of Calcium Hydroxide Research Articles

Autotransplantation of a Mandibular Third Molar: A Case Report with 5 Years of Follow-up

This paper describes the autologous transplantation of a mandibular right third molar to replace the residual roots of the second molar in the same quadrant, preserving function and aesthetics. A 5-year clinical and radiographic follow-up was undertaken. After transplantation, the donor tooth received endodontic treatment and placement of calcium hydroxide, which was periodically replaced every 3 months until the filling of the root canals, totalizing a period of 1-year, when apical closure was confirmed. The tooth was in perfect functional and aesthetic conditions 5 years after beginning of treatment. Autotransplantation is a feasible option for replacing missing teeth when a donor tooth is available. The autotransplantation of a right mandibular third molar with compromised function and aesthetics to replace the residual roots resulting from coronal destruction due to extensive carious lesion of the second molar in the same quadrant was a viable treatment alternative.

The effect of calcium hydroxide placement on pH and calcium concentration in periapical environment: An in vitro study

Comparing the calcium concentration and pH levels of Ca(OH) 2 medicament placing in pulp chamber and root canal. Ninety-nine extracted human mandibular second premolars were instrumented to size #40 k file. Nine teeth served as the control group and the remaining teeth were assigned into two groups. Group 1-Ca(OH) 2 was placed in the dried pulp chamber, while root canals remained wet with normal saline; group 2-Ca(OH) 2 was placed in dried root canals. In control group, canals remained wet without medication. Each group was divided into 3 sub-groups of 15 teeth in which pH and calcium concentration were measured in three intervals of 2 days, 1 week, and 2 weeks by pH meter and atomic absorption spectrometer system, respectively. Findings were assessed using Kruskal-Wallis and t-test. At 1 and 2 weeks, the calcium concentration had increased without being significantly different from Ca(OH) 2 placed either in the root canal or in the pulp chamber. Ca(OH) 2 placed in the pulp chamber or root canal provided similar pH values (P=0.362). Placing Ca(OH) 2 in pulp chamber is as effective as placing it in the root canal.

The effects of short-term application of calcium hydroxide on dentin fracture strength

Objectives: This in vitro study investigated whether short-term application of calcium hydroxide in the root canal system for 1 and 4 wk affects the fracture strength of human permanent teeth. Materials and Methods: Thirty two mature human single rooted mandibular premolars in similar size and dentin thickness without decay or restorations were hand and rotary instrumented and 16 teeth vertically packed with calcium hydroxide paste and sealed coronally with caviton to imitate the endodontic procedure and the other 16 teeth was left empty as a control group. The apicies of all the samples were sealed with resin, submerged in normal saline and put in a storage box at 37℃ to mimic the oral environment. After 1 and 4 wk, 8 samples out of 16 samples from each group were removed from the storage box and fracture strength test was performed. The maximum load required to fracture the samples was recorded and data were analysed statistically by the two way ANOVA test at 5% significance level. Results: The mean fracture strengths of two groups after 1 wk and 4 wk were similar. The intracanal placement of calcium hydroxide weakened the fracture strength of teeth by 8.2% after 4 wk: an average of 39.23 MPa for no treatment group and 36.01 MPa for CH group. However there was no statistically signif- icant difference between experimental groups and between time intervals. Conclusions: These results suggest that short term calcium hydroxide application is available during endodontic treatment. ABSTRACT 1 Shin EJ, Dental school student, Chonnam National University School of dentistry,

Effects of Intracanal Mineral Trioxide Aggregate and Calcium Hydroxide During Four Weeks on pH Changes in Simulated Root Surface Resorption Defects: An In Vitro Study Using Matched Pairs of Human Teeth

Introduction Diffusion of hydroxyl ions from intracanal calcium hydroxide (CH) through dentin is used to arrest external inflammatory root resorption. However, long-term and short-term CH placement has been associated with an increased risk of root fracture. Intracanal mineral trioxide aggregate (MTA) might provide an alternative to CH as a source of hydroxyl ions. This in vitro study compared the effects of intracanal MTA and CH on hydroxyl ion diffusion through dentin by measuring pH changes over time in simulated root surface resorption defects prepared in matched pairs of teeth; the null hypothesis tested was that there is no difference. Methods Root surface cavities were prepared 5 mm from the apex in extracted human permanent anterior teeth (21 matched pairs) and 7 additional teeth (controls). Root canals were instrumented to size 50/.04 and filled with either tooth-colored MTA (ProRoot) or CH (UltraCal XS); control teeth were filled with saline. The pH in root surface cavities was measured at 3 hours, 24 hours, 1 week, 2 weeks, 3 weeks, and 4 weeks. Results In controls, pH readings did not differ significantly during the 4 weeks ( P > .05, repeated-measures analysis of variance [ANOVA]). For the experimental intragroup effects, significant pH changes occurred over time in the MTA group ( P = .005, repeated-measures ANOVA) and the CH group ( P < .0001). For the experimental intergroup effects, the overall mean pH was higher in the MTA group (8.66; standard error [SE], 0.07) compared with the CH group (8.46; SE, 0.07) ( P = .014, paired t test). At 4 weeks pH was higher in the MTA group (8.30; SE, 0.16) compared with the CH group (7.90; SE, 0.11) ( P = .011); at all other time points intergroup differences were insignificant. The null hypothesis was rejected. Conclusions Intracanal MTA and CH groups differed in their overall effect on pH measured in simulated root surface resorption defects. At 4 weeks intracanal placement of MTA compared with CH resulted in a small but significantly higher pH.

A comparison of two techniques for the removal of calcium hydroxide from root canals

To compare the ability of two irrigant regimens to remove calcium hydroxide (CH) mixed with different vehicles from root canal walls. The root canals of 92 freshly extracted bovine incisor teeth were prepared with a step-back technique and randomly assigned into two experimental groups (n = 40), whilst the remaining teeth (n = 12) served as positive and negative controls. In each experimental group, ten teeth were assigned to each CH preparation: G1 - CH powder; G2 - CH + saline solution; G3 - CH + polyethylene glycol (PEG); G4 - CH + PEG + camphorated paramonochlorophenol (CPMC). The negative control did not receive CH placement, and the positive control received the intracanal dressing, but no subsequent removal. After 7 days, the CH was retrieved using manual or passive ultrasonic irrigation (PUI). The roots were grooved longitudinally and split into halves. Images of each half of the canal were acquired by a digital camera, and the percentage of CH coated surface area in relation to the surface area of each third of the canal was calculated. The results were statistically analysed with anova with post hoc Tukey test with the null hypothesis set as 5%. Remnants of medicament were found in all experimental groups. The positive control group had complete coverage of the canal walls with CH in contrast to the negative control (P < 0.001). Considering the cervical and middle thirds, the percentage of CH retention in G1 was significantly lower using PUI (26.6% and 32.2%, respectively) than the manual (38.7% and 46.1%, respectively) technique (P < 0.05). No significant differences were observed between G2, G3 and G4 in all thirds and the experimental groups at the apical third (P > 0.05). Neither syringe injection nor PUI methods were efficient in removing the inter-appointment root canal medicaments. Remnants of medicament were found in all experimental groups regardless of the vehicle used.

Evaluation of the effects of anterior permanent teeth with crown fractures

Objective To study the treatment of anterior permanent teeth with crown fractures.Methods 68 anterior permanent teeth of 56 children were collected in this investigation.10 teeth with enamel fractures only were treated by mehtod of blunting the sharp fracture edges.27 teeth with dentin fractures,but without pulp exposure,were protected by calcium hydroxide.31 teeth with dentin fractures and with pulp exposure were treated by partial pulpotomy.Results 10 enamel factured teeth had vital pulp after two years retrospect.The success rate of calcium hydroxide placement group was 81.4%,that of the partial pulpotemy was74.2%.Conclusion Different types of crown fractures should be treated by different methods.Pulpotomy is a successful treatment method for crown fractures with pulp exposure. Key words: Children; Anterior teeth; Crown fracture

A Comparative Study of Three Different Techniques of Placing Calcium Hydroxide as Intra-Canal Dressing

Background and objective: Calcium hydroxide used in modern root canal therapy as intra-canal dressing. It is used due to its antimicrobial effect. In this study trhree different techniques of placing calcium hydroxide as intra-canal dressing are used to determine the most effective method of using calcium hydroxide as intra-canal dressing. Methods: Eighteen mandibular premolars were randomly collected, root prepared and filled with calcium hydroxide paste in one of three techniques (1) using file and absorbent paper point with vertical compaction (2) using special syringe with vertical compaction (3) using lentulo drill with vertical compaction. Radiographs were taken to evaluate paste compactness. Results: The placement of calcium hydroxide with lentulo drill aided by vertical compaction showed the lowest number of empty spaces followed by using special syringe with vertical compaction and the highest number of empty spaces was shown by using file aided by absorbent paper point and vertical compaction. Conclusion: The use of lentulo drill aided by vertical compaction gave the best result of using calcium hydroxide paste as intra-canal dressing.

Effect of calcium hydroxide intracanal dressing on the bond strength of a resin-based endodontic sealer

The aim of this in vitro study was to evaluate the bond strength of Epiphany resin-based sealer to dentin walls after placement of calcium hydroxide [Ca(OH)2] dressings. Fifteen extracted single-rooted human teeth were instrumented using 2.5% NaOCl + EDTA as irrigants. The teeth were randomly assigned to 3 groups (n=5), according to the intracanal dressing: G1= Ca(OH)2 + saline; G2= Ca(OH)2 + 2% chlorhexidine gluconate (CHX) gel; and G3= saline (control). After 10 days of storage in 100% humidity at 37 degrees C, the dressings were removed and the root canals were filled with Epiphany sealer. After additional 48 h of storage, the specimens were sectioned transversally into 2-mm-thick discs. Push-out tests were performed (1 mm/min, Instron 4411) and the maximum loads at failure were recorded in MPa. One-way ANOVA and Newman-Keuls tests showed a statistically significant decrease in bond strength when a Ca(OH)2 dressing was used before root canal filling with Epiphany (G1= 10.18 +/- 1.99 and G2= 9.98 +/- 2.97) compared to the control group (13.82 +/- 3.9) (p< 0.05). It may be concluded that the use of Ca(OH)2 as an intracanal dressing material affected the adhesion of Epiphany to the root canal walls, but even though the values were within the acceptable range found in the literature.

Effect of Irrigants and Cementum Injury on Diffusion of Hydroxyl Ions through the Dentinal Tubules

This study measured hydroxyl ion diffusion through dentinal tubules into a bathing solution. Eighty single-canal, instrumented teeth were divided into 8 groups. Control groups 1 and 3 were irrigated with 10 mL 0.9% saline and 10 mL 6% sodium hypochlorite (NaOCl), respectively. Control groups 5 and 7 were irrigated with 3 mL and 1 mL 17% ethylenediaminetetraacetic acid (EDTA) and then 10 mL 6% NaOCl, respectively. Experimental groups 2, 4, 6, and 8 were irrigated as groups 1, 3, 5, and 7, followed by placement of calcium hydroxide (Ca(OH) 2) into canals. Bathing solution pH was recorded for 30 days, a cementum defect was made, and then pH was recorded for another 30 days. With a paired difference test, average pH during steady state was statistically different and higher after the defect ( P < .001). With Tukey multiple comparisons, post-defect pH for group 6 was found to be significantly greater ( P < .01) than in other groups. This study indicated final canal irrigation with 3 mL 17% EDTA and 10 mL 6% NaOCl before Ca(OH) 2 placement allowed the greatest hydroxyl ion diffusion to the root surface.

The effect of calcium hydroxide root filling on dentin fracture strength

This in vitro study measured the effect of calcium hydroxide root filling on the microtensile fracture strength (MTFS) of teeth. A total of 40 extracted human disease-free permanent maxillary incisors were hand and rotary instrumented and vertically compacted with United States Pharmacopeia (USP) calcium hydroxide. The teeth were stored in a moist environment for 7, 28, and 84 days. As a control group, 10 teeth were vertically compacted with gutta percha and sealer. The MTFS of the teeth was measured (Mpa) using an Instron machine. Data were assessed statistically using an unpaired t-test (P value). The intracanal placement of calcium hydroxide weakened the MTFS of teeth by 13.9 Mpa per 77 days: an average of 0.157 MPa day-1. Between 7 and 84 days, the MTFS of the dentin was reduced by 43.9%. This difference was statistically significant (P < 0.05). A statistical difference (P < 0.05) was observed between the mean MTFS of the calcium hydroxide-filled dentin between 7 days (45.7 MPa) and 28 days (35.6 MPa) and also between 7 and 84 days (31.8 MPa). There was also a significant difference (P < 0.05) between the MTFS of the calcium hydroxide-filled dentin after 84 days (31.8 MPa) and the gutta percha-filled dentin (41.3 MPa) when used as a control root filling material. The weakening of the dentin by 23-43.9% following root canal filling with calcium hydroxide provides compelling evidence to re-evaluate the daily usage of this material in endodontic therapy.

Dentinal pH changes following electrophoretically activated calcium hydroxide ions in the root canal space of bovine teeth

The aim of the study was to evaluate pH changes of external root dentin surface at different depths following electrophoretic activation of calcium hydroxide (CH) in the root canals. For the study, 60 cavities were drilled on three external root surfaces of 20 bovine teeth specimens to obtain remaining dentin thickness (RDT) of 0.3, 0.7 and 1.0 mm. CH paste was inserted in the lumens. In the experimental group (10 specimens) CH paste was electrophoretically activated. Microelectrode was used to measure pH changes in the cavities immediately after placement of CH, following electrophoretical activation, and after 30 days storage. A significant (P < 0.05) increase in pH following electrophoresis was found in all specimens in the experimental group. Cavities with 0.4 mm RDT showed a maximal pH increase to the value of 11.3 +/- 0.4. In the control group no change in pH was observed after 3 min. A similar increase in pH was observed in both groups after 30 days. The pH changes were significantly depended on the RDT (P < 0.05) in all groups. Electrophoretically activated CH could significantly increase dentinal pH of external root surface within minutes up to 30 days.

Investigation of pH at different dentinal sites after placement of calcium hydroxide dressing by two methods

The dentin pH at different sites following placement of calcium hydroxide paste using 2 different methods was evaluated. One hundred twenty Extracted teeth were instrumented and randomly divided into 6 different groups. Then they were dressed with calcium hydroxide by 2 different methods using paper points or Lentulo spiral, according to their respective groups, and stored. After the experimental period of time, half of the samples were cut transversally into slices and the other half split longitudinally and rinsed with distilled water. The dentin pH of cervical, middle, and apical thirds was measured from the root canal wall surface and 1 mm away from the root canal lumen in the inner dentin. The results were compared and statistically analyzed. The highest pH values were obtained on the root canal walls when the calcium hydroxide was placed with Lentulo spiral filler (P > .05). There was a significant reduction in pH values in the inner dentin. When the cross sections of teeth were compared at 7 days, the Lentulo group was statistically different only in the apical third. Placement of the calcium hydroxide paste with a Lentulo spiral with subsequent compaction with the blunt end of a sterile paper point obtained a higher pH value on the canal walls and in the inner dentin than paper points only.

Effect of 2% Chlorhexidine Gel as an Intracanal Medication on the Apical Seal of the Root-Canal System

The purpose of this study was to determine what effect intracanal medications might have on the apical seal of the root-canal system. Forty-two teeth were cleaned and shaped in a crown-down manner to a size #50 K-file. The teeth were divided into three groups: (A) immediate obturation; (B) intracanal placement of calcium hydroxide placed for 14 days; and (C) 2% chlorhexidine gel placed for 14 days. After 14 days, these materials were removed using copious irrigation and obturation was completed on groups B and C. Obturation was performed using the continuous wave of condensation technique using AH Plus sealer in all groups. Leakage was evaluated 60 days after obturation by using a fluid-filtration device. Using the one-way ANOVA test, there was no statistically significant difference in leakage between the three groups. Under the conditions of this study, 2% chlorhexidine gel and calcium hydroxide paste did not adversely affect the apical seal of the root-canal system.

Intracanal Placement of Calcium Hydroxide: A Comparison of Techniques, Revisited

The goal of this in vitro study was to compare the effectiveness of three different placement techniques of calcium hydroxide paste in a curved canal. An acrylic resin block with a 44-degree curvature was instrumented to a #40 Flex-R file. The canal was filled with radiopaque calcium hydroxide paste using the following techniques: group 1, the paste was injected with an Ultradent tip; group 2, the paste was injected as in group 1 and followed by a size 35 Lentulo to working length; and group 3, the paste was placed with a size 35 Lentulo only, to working length. Each technique was performed 25 times. The radiodensity of the simulated canal was measured at 1, 3, 5, and 7 mm from the canal terminus. At 1 mm, the Lentulo was significantly better than the other two techniques. At 3 mm, the Lentulo technique and the combined technique were better than the Ultradent tip alone.

In vitro antimicrobial effect of chlorhexidine‐impregnated gutta percha points on Enterococcus faecalis

To evaluate the in vitro antimicrobial effect of chlorhexidine-impregnated gutta percha points, Roeko activ point (Roeko, Langenau, Germany) on Enterococcus faecalis. Human maxillary premolar roots were prepared with.04 rotary ProFile instruments to a master apical file size 40, autoclave-sterilized and then infected with E. faecalis (ATCC 29212) for 3 weeks. Baseline controls were carried out verifying negligible effects of plain gutta percha cones on E. faecalis. Subsequent to intracanal placement of calcium hydroxide, 'activ points' or saline (positive control) and the 2-week incubation in 54 root specimens, dentine sampling at depths of 100 and 250 micro m was carried out using.04 rotary ProFile instruments at sizes 60 and 90 to assess the quantity of bacteria present. Inactivating agents were used prior to sampling and the colony-forming units (CFU) of E. faecalis were then plate-counted after culturing. Statistical analysis was completed using the paired t-test. In comparison to the positive control, treatment with calcium hydroxide (P = 0.000 and 0.000) or activ points (P = 0.000 and 0.002) produced significantly lower colony counts of E. faecalis at dentine depths of 100 and 250 micro m, respectively. Calcium hydroxide (2.10 x 102 CFU mL-1) was significantly more effective than activ points (1.58 x 103 CFU mL-1) at 100 micro m (P = 0.013), but not at 250 micro m (P = 0.353). Neither of these two medications was able to eliminate E. faecalis completely. Chlorhexidine-impregnated activ points did not possess an in vitro inhibitory activity strong enough to eliminate E. faecalis completely from infected dentinal tubules.

Reduction of Intracanal Bacteria Using Nickel-Titanium Rotary Instrumentation and Various Medications

The purpose of this study was to evaluate the extent of bacterial reduction with nickel-titanium rotary instrumentation and 1.25% NaOCl irrigation. Also, the additional antibacterial effect of calcium hydroxide for >1 wk was tested. Forty-two subjects with radiographic and clinical signs of chronic apical periodontitis were recruited. The canals were sampled before treatment, during and after instrumentation, and after treatment with calcium hydroxide and the samples incubated anaerobically for 7 days at 37 degrees C. The bacteria from each sample were quantified and the log10 values were used for calculations and comparisons. The initial sample confirmed infection of the canals. There was a significantly greater pattern of reduction of bacteria when NaOCl was used as an irrigant, compared with sterile saline (p < 0.05). After instrumentation with NaOCl irrigation, 61.9% of canals were rendered bacteria-free. The placement of calcium hydroxide for at least 1 wk rendered 92.5% of the canals bacteria free. This was a significant reduction, compared with NaOCl irrigation alone (p = 0.0001). The results of this study indicate that NaOCl irrigation with rotary instrumentation is an important step in the reduction of canal bacteria during endodontic treatment. However this method could not consistently render canals bacteria-free. The addition of calcium hydroxide intracanal medication should be used to more predictably attain this goal.

Influence of Mixing Vehicle on Dissociation of Calcium Hydroxide in Solution

The antimicrobial effects of aqueous preparations of calcium hydroxide have been demonstrated in the past. Calcium hydroxide, when dissolved in water, dissociates into hydroxide and calcium ions. The presence of hydroxide ions in a solution makes it antimicrobial. Recently it was shown that the use of glycerin as a mixing vehicle facilitates placement of calcium hydroxide in the root canals. The influence of nonaqueous mixing vehicles on the dissociation of calcium hydroxide is not clearly understood. In this study the conductivity of aqueous and nonaqueous solutions of calcium hydroxide was measured. The conductivity values for saturated solutions of calcium hydroxide in water was 7.3+/-3 mS/cm. The conductivity of calcium hydroxide in pure glycerin or propylene glycol was essentially zero. It was concluded that use of nonaqueous mixing vehicles may impede the effectiveness of calcium hydroxide as a root canal dressing.

Five methods of calcium hydroxide intracanal placementAn in vitro evaluation

Objective. The purpose of this study was to evaluate root canal dressing with calcium hydroxide paste using 5 techniques of placement. Study design. After endodontic preparation, each of 50 single-rooted premolars was filled with calcium hydroxide paste through use of one of the following techniques: Gutta-Condensor, MecaShaper, K-type ultrasonic file, Lentulo, and Pastinject. Radiographs of all 3 third root zones were made after cleaning and shaping and obturation. Density measurements (in pixels) were registered by means of an image analyzer and then compared through use of analysis of variance and Newman-Keuls multiple means tests. Results. With respect to average filling density, the techniques ranked as follows, in ascending order: Gutta-Condensor, MecaShaper, K-type ultrasonic file, Lentulo, and Pastinject. There was a significant difference ( P < .0009) between the Gutta-Condensor and Pastinject techniques, between the MecaShaper and Pastinject techniques, and between the ultrasonic file and Pastinject techniques; all favored the Pastinject. There were no significant differences between the Gutta-Condensor, MecaShaper, ultrasonic file, and Lentulo techniques or between the Lentulo and Pastinject techniques. Conclusions. The use of a specially designed paste carrier (the Pastinject) improved calcium hydroxide placement in root canals. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;89:349-55)

Placement of calcium hydroxide in simulated canals: Comparison of glycerin versus water

Calcium hydroxide (Ca(OH)2) is an intracanal medicament used as an antimicrobial agent, temporary obturant, and for apexification. Placement should be controlled for the maximum biological effect. This study evaluated and compared the effectiveness of delivery of Ca(OH)2 mixed with water or with glycerin as to (a) length of placement and (b) density of fill at different levels. Fifty-six simulated canals with moderate curvature were prepared to #60 using the step-back technique. Ca(OH)2 was mixed with either water (28 canals) or glycerin (28 canals) into a thick paste and placed with lentulo spirals. Radiographs were made and blindly assessed. Results showed that glycerin was statistically significantly superior (p < 0.05) to water as to (a) length of fill and (b) density in the coronal, middle, and apical thirds. Of particular interest was the apical third, in which 0% of water and 50% of glycerin Ca(OH)2 pastes were completely dense.

Poster Clinic #22 — Effect of glycerin on the placement of calcium hydroxide

Poster Clinic #22 — Effect of glycerin on the placement of calcium hydroxide