pH Of Calcium Hydroxide Research Articles

Evaluation of the antimicrobial efficacy of different nonsteroidal anti-inflammatory drugs alone or in combination with calcium hydroxide intracanal medicament: an in vitro study.

This study explored the antimicrobial effects of ketoprofen, piroxicam, and celecoxib alone or combined with calcium hydroxide (CH) against two strains of Enterococcus faecalis (E. faecalis) and assessed the influence of such combinations on the pH of CH. Minimum inhibitory concentrations (MICs) of the three tested NSAIDs were determined. Tested pastes were placed into wells punched in seeded agar plates and the bacterial inhibition zones were measured. Antibiofilm activity was assessed against 3 weeks of biofilm induced in bovine dentine blocks. The pH of the pastes was measured at four-time intervals. MIC values were 3.12, 25, and 25mg/ml for ketoprofen, piroxicam, and celecoxib, respectively, and were similar for both bacterial strains except for celecoxib, which showed 8% growth at the highest tested concentration against vancomycin-resistant E. faecalis. Ketoprofen had the largest mean inhibition zone that was comparable to CH. None of the six tested pastes exhibited antibiofilm activity of a significant level in comparison to CH. A noticeable increase in the antibiofilm activity was found when 20% NSAIDs were added to CH while maintaining an alkaline pH. Ketoprofen was found to be the most effective among the tested NSAIDs. Although its effect was comparable to CH, adding ketoprofen at a ratio of 20% resulted in 50% higher antimicrobial action than CH alone. Accordingly, incorporating NSAIDs in inter-appointment dressing has the potential to utilize their anti-inflammatory, local analgesic, and antibacterial actions, which overcome the limitations of CH and improve the outcome of root canal treatment.

Calcium hydroxide and niobium pentoxide treatment effects before MTA placement.

The aim of this study was to evaluate the effect of calcium hydroxide (CH) and niobium pentoxide (NP) pretreatment on pH, dentin microhardness and sealing of Mineral Trioxide Aggregate (MTA; Angelus). The pH of CH, NP and CH-NP (3:1) was evaluated in neutral and acidic simulated tissue fluid over 28days. The Vickers microhardness was measured in forty 4mm coronal root slices filled with pretreatment materials stored in medium for 1, 7, 28days. Forty 10mm roots were packed with pretreatment materials, irrigated after 24h, then a 3mm MTA plug was placed. Sealing ability was evaluated after 7days using fluid filtration method. Statistics was performed using ANOVA and post hoc Tukey HSD tests. Addition of NP to CH maintained the alkalinity of CH, increased the microhardness of root dentin and reduced the microleakage. CH-NP can be effectively used as a pretreatment medicament in root canals requiring placement of MTA under acidic conditions.

An Evaluation of the Effect of Different Vehicles on Changes in the pH of Calcium Hydroxide

An Evaluation of the Effect of Different Vehicles on Changes in the pH of Calcium Hydroxide

Ions Release and pH of Calcium Hydroxide-, Chlorhexidine- and Bioactive Glass-Based Endodontic Medicaments.

This study evaluated pH and release of calcium, sodium and phosphate ions from different medications in human dentin. Fifty premolars were prepared and randomly divided into groups: (CHX) - 2% chlorhexidine gel; (CHX + CH) - CHX + calcium hydroxide PA; (CH) - CH + propylene glycol 600; (NPBG) - experimental niobium phosphate bioactive glass + distilled water; (BG) - bioactive glass (Bio-Gran) + distilled water. The specimens were immersed in deionized water and the pH variations were measured. The quantification of ions in the solutions was made by inductively coupled plasma - atomic emission spectroscopy (ICP/AES) at 10 min, 24 h, 7, 14, 21 and 30 days. The results were analyzed by ANOVA and Tukey`s test, with a significance level of 5%. CH had the highest level of calcium ions release at 30 days, while CHX and BG released more sodium ions. BG, NPBG and CHX released a higher amount of phosphate ions. The pH of CH was significantly higher compared with the other groups. CH favored the greatest increase of pH and calcium ions release. The bioactive glasses released more sodium and phosphate ions and presented an alkaline pH immediately and after 30 days.

Antimicrobial Activity and pH of Calcium Hydroxide and Zinc Oxide Nanoparticles Intracanal Medication and Association with Chlorhexidine.

To evaluate pH and antibacterial activity of pastes with calcium hydroxide [Ca(OH)2] and zinc oxide (ZnO) microparticles (micro) or nanoparticles (nano) and association with 0.4% chlorhexidine against Enterococcus faecalis. The following pastes were analyzed: Ca(OH)2/ZnO micro, (2) Ca(OH)2/ZnO nano, (3) Ca(OH)2/ ZnO micro + 0.4% chlorhexidine, (4) Ca(OH)2/ZnO nano + 0.4% chlorhexidine. Antibacterial activity against E. faecalis was evaluated by agar diffusion test. The direct contact test on planktonic cells of E. faecalis was performed for 30 and 60 seconds. Root canals from bovine teeth were filled with the pastes and pH was evaluated after 1, 7, 14, 21, 30 and 60 days. The data obtained were submitted to the statistical tests analysis of variance (ANOVA) and Tukey or Kruskal-Wallis and Dunn test, with a 5% significance level. Calcium hydroxide and zinc oxide nano, and the pastes with 0.4% chlorhexidine were more effective in agar diffusion test. In the direct contact test, the pastes with chlorhexidine showed the highest effect after 30 seconds. All pastes eliminated E. faecalis after 60 seconds. All pastes promoted an increase in pH. The highest increase in pH was observed with nanoparticle medications after 1 and 7 days (p < 0.05). After this period, the pastes presented similar pH increase. It was concluded that calcium hydroxide and zinc oxide nanoparticles promoted greater initial alkalinization. The antimicrobial activity of the pastes against E. faecalis is favored by the association with chlorhexidine. Although nanoparticles of calcium hydroxide and zinc oxide promoted antibacterial effect, the activity against E. faecalis is favored by association with chlorhexidine.

The Influence of Dentine on the pH of Calcium Hydroxide, Chlorhexidine Gel, and Experimental Bioactive Glass-Based Root Canal Medicament.

Objectives. To evaluate the influence of dentine on the pH of different medications in standardized simulated canals. Materials and Methods. Forty resin blocks were divided into groups with and without dentine powder, as follows: 2% chlorhexidine gel; 2% chlorhexidine gel associated with calcium hydroxide PA; calcium hydroxide PA delivered in propylene glycol 600; and NPG delivered in distilled water. The dentine powder was obtained from the root dentine of bovine teeth and added to the medications. The simulated canals were placed in containers with 1.5 mL of deionized water and pH was monitored in multiple intervals, up to 30 days. The mean pH values were calculated and submitted to statistical analysis using paired Student's t-test and ANOVA complemented by the Tukey test (p < 0.05). Results. There was no statistical difference between the groups with and without dentine powder (p > 0.05). The pH values of calcium hydroxide were significantly higher than those of NPG in the first 24 hours (p < 0.05). After 7 days, both behaved in a similar manner. Conclusion. The addition of dentine powder to the medications evaluated did not alter the pH of the external solution in any of the time points tested.

Influence of Dentin from the Root Canal Walls and the Pulp Chamber Floor on the pH of Intracanal Medicaments

IntroductionThe objective of this study was to evaluate the alterations in the pH of calcium hydroxide (Ca[OH]2), 2% chlorhexidine (CHX) gel, and their combination after adding dentin powder from the root canal walls and the pulp chamber floor. MethodsCa(OH)2 paste, 2% CHX gel, and their combination were examined. Dentin powder was obtained from the root canal walls and the pulp chamber floor of bovine teeth and added as 1.8% to the volume of the medications. The pH values of the mixtures were assessed immediately after preparation, after 24 hours, and on days 7 and 14. Data were analyzed statistically by analysis of variance and the Student's t test (P = .05). ResultspH values of Ca(OH)2 were always above 12 in the presence or absence of dentin powder during the 14 days of the study. A significant decrease in pH values of Ca(OH)2 was observed after 14 days when dentin from the root canal wall was added (P < .001). The pH values of CHX gel were significantly increased by the presence of dentin (P = .001). The t test showed a significant difference in the increase of the pH values when the different dentin types were added (P = .002). The pH of the Ca(OH)2 and CHX gel combination was not influenced by dentin powder from the root canal walls, and a reduction was observed after 14 days, exactly like in the control group. The pH values of the combination did not alter after 14 days when pulp chamber floor dentin was added. ConclusionsThe different dentin types variably affect the pH of Ca(OH)2 paste, 2% CHX gel, and their combination in the studied periods.

Loss of Hydroxyl Ions from Gutta-Percha Points with Calcium Hydroxide in Their Composition: An In Vivo Study

The aim of this study was to quantify variations in the pH of calcium-hydroxide, gutta-percha cones that had remained for 1 week inside the root canals of molars or premolars whose endodontic treatment could not be concluded in a single visit. All teeth were instrumented and dried before the placement of the points. The cones were removed, and placed in vials with distilled water. Additional, new gutta-percha cones were also studied as a control. The pH was measured by a pH meter, model CRISON MicropH 2001. The average pH mensurations obtained for new, calcium-hydroxide, gutta-percha points was 10.11; for cones that were used 1 week, it was 7.08. There was a statistically significant difference observed between the two groups by the Student's t test (p > 0.001). After 7 days, a significant decrease takes place in the alkalinity of these points.

Mechanisms involved in the resistance of Enterococcus faecalis to calcium hydroxide.

This study sought to clarify the mechanisms that enable E. faecalis to survive the high pH of calcium hydroxide. E. faecalis strain JH2-2 was exposed to sublethal concentrations of calcium hydroxide, with and without various pretreatments. Blocking agents were added to determine the role of stress-induced protein synthesis and the cell wall-associated proton pump. E. faecalis was resistant to calcium hydroxide at a pH of 11.1, but not pH 11.5. Pre-treatment with calcium hydroxide pH 10.3 induced no tolerance to further exposure at pH 11.5. No difference in cell survival was observed when protein synthesis was blocked during stress induction, however, addition of a proton pump inhibitor resulted in a dramatic reduction of cell viability of E. faecalis in calcium hydroxide. Survival of E. faecalis in calcium hydroxide appears to be unrelated to stress induced protein synthesis, but a functioning proton pump is critical for survival of E. faecalis at high pH.

Mechanisms Involved In The Resistance Of Enterococcus Faecalis To Calcium Hydroxide

ABSTRACTIntroductionThe species Enterococcus faecalis has been recovered in a high proportion of endodontic failures – approximately one‐third of failed cases with recoverable bacteria contain monoinfections of the microorganism. Eradication of E. faecalis from an infected root canal is difficult, which means that it is a significant clinical problem in endodontic treatment. E. faecalis is known to be resistant to the alkaline bactericidal effect of calcium hydroxide, yet the survival mechanisms of E. faecalis that enable it to tolerate exposure to the high pH of calcium hydroxide are poorly understood.Because endodontic treatment involves repeated or alternate use of antimicrobial agents at various stages, these conditions could adapt or ‘pre‐treat’ cells by eliciting a stress response that enhances their survival. An ability to mount a stress response involving synthesis of general or specific stress‐induced proteins is an important survival mechanism for many bacteria. The production of these stress‐induced proteins protects cells from adverse conditions, facilitating cell recovery when more favourable conditions are re‐established. This study sought to clarify the mechanisms that enable E. faecalis to survive the high pH of calcium hydroxide.MethodsE. faecalis strain JH2–2. was exposed to sub‐lethal concentrations of calcium hydroxide, with and without various pre‐treatments. Blocking agents were added to determine the role of stress‐induced protein synthesis and the cell wall‐associated proton pump.ResultsE. faecalis was resistant to calcium hydroxide at a pH of 11.1, but not pH 11.5. Pre‐treatment with calcium hydroxide pH 10.3 induced no tolerance to further exposure at pH 11.5. No difference in cell survival was observed when protein synthesis was blocked by Chloramphenicol during stress induction. However, addition of the proton pump inhibitor, CCCP, resulted in a dramatic reduction of cell viability of E. faecalis in calcium hydroxide.ConclusionsThis study confirmed that E. faecalis is resistant to killing by calcium hydroxide. An adaptive response in alkaline pH and stress‐induced protein synthesis do not play a role in cell survival. However, a functioning proton pump with the capacity to drive protons into the cell and acidify the cytoplasm is critical for survival of E. faecalis at high pH. These findings contribute to our understanding of the response by E. faecalis to the antimicrobial action of calcium hydroxide and may open the possibility of novel approaches to address this clinical problem in endodontic treatment.

Effect of four vehicles on the pH of calcium hydroxide and the release of calcium ion

Nonsetting calcium hydroxide pastes are commonly used in endodontic practice. The desired therapeutic effect of such a paste is in part dependent on the dissociation of calcium hydroxide into hydroxy ion and calcium ion. This in turn is influenced by the vehicle used to make the paste. This investigation attempts to quantitatively estimate the release of hydroxyl ion and calcium ion from pastes made by using distilled water, normal saline solution, camphorated monochlorophenol and also an experimental vehicle, propylene glycol. The results of this study indicate that propylene glycol induces the most favorable release characteristics of the two ionic species.

The effect of three vehicles on the pH of calcium hydroxide

Dry calcium hydroxide powder was mixed with either cresatin, camphorated parachlorophenol, or saline solution to form a paste. The pH of each paste was measured and compared. Cresatin, when used as the mixing vehicle, did not produce or maintain as high a pH as the other two mixing vehicles.

Camomile Therapy in Dentistry: its Possible Application in Vincent’s Infection and Suppurative Paradentosis

The objective of this study was to evaluate the alterations in the pH of calcium hydroxide (Ca[OH]2), 2% chlorhexidine (CHX) gel, and their combination after adding dentin powder from the root canal walls and the pulp chamber floor.Ca(OH)2 paste, 2% CHX gel, and their combination were examined. Dentin powder was obtained from the root canal walls and the pulp chamber floor of bovine teeth and added as 1.8% to the volume of the medications. The pH values of the mixtures were assessed immediately after preparation, after 24 hours, and on days 7 and 14. Data were analyzed statistically by analysis of variance and the Student's t test (P = .05).pH values of Ca(OH)2 were always above 12 in the presence or absence of dentin powder during the 14 days of the study. A significant decrease in pH values of Ca(OH)2 was observed after 14 days when dentin from the root canal wall was added (P < .001). The pH values of CHX gel were significantly increased by the presence of dentin (P = .001). The t test showed a significant difference in the increase of the pH values when the different dentin types were added (P = .002). The pH of the Ca(OH)2 and CHX gel combination was not influenced by dentin powder from the root canal walls, and a reduction was observed after 14 days, exactly like in the control group. The pH values of the combination did not alter after 14 days when pulp chamber floor dentin was added.The different dentin types variably affect the pH of Ca(OH)2 paste, 2% CHX gel, and their combination in the studied periods.