{"content"=>"Diffusion of calcium hydroxide through dentinal tubules of retreated root canals: An study.", "i"=>{"content"=>"in vitro"}} (original) (raw)
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Jundishapur journal of natural pharmaceutical products, 2014
Intra canal medicaments are used to reduce the number of bacteria and reinfection in endodontic procedures. Calcium Hydroxide was introduced to endodontics by Herman as an intracanal antimicrobial agent. The aim of this study was to present an injectable formulation of calcium hydroxide then compare the final pH of this new formulation with Metapaste and evaluate the effect of a mixture of Calcium Hydroxide powder with water on human extracted teeth. A total of 49 extracted human single-canal roots without caries and visible microcracks were included in this study. The teeth were decoronated and length of teeth was measured 1 mm anatomic apex. The canals were prepared using step-back technique. A cavity was created in the middle third of the buccal surface of all roots. The teeth were randomly divided into five groups: Group A (n = 15): In this group the root canals were filled with a mixture of calcium hydroxide powder and distilled water. Group B (n = 15): Included roots that were...
Endodontic re-instrumentation enhances hydroxyl ion diffusion through radicular dentine
International Endodontic Journal, 2013
dos Santos LGP, Felippe WT, Teixeira CS, Bortoluzzi EA, Felippe MCS. Endodontic re-instrumentation enhances hydroxyl ion diffusion through radicular dentine. International Endodontic Journal, 47, 776-783, 2014. Aim To evaluate the diffusion of hydroxyl ions from calcium hydroxide paste (CH) before root canal filling and after retreatment. Methodology After preparation of 60 root canals, the cementum layer was removed, and the canals and root surfaces were treated for smear layer removal. The apical third of roots was covered with adhesive. The canals were filled with CH, and the teeth were placed in individual vials containing 10 mL of distilled water, which had its pH measured after 7, 14, 21 and 28 days (pH1). The root canals were then divided into five groups and filled with Resilon/Real Seal (G1) or gutta-percha and Endofill (G2), Sealapex (G3), AH Plus (G4) or MTA Fillapex (G5) sealers. After storage for 7 days, the root canals were retreated. The CH was again inserted into the canals, and the teeth were placed in new vials containing 10 mL of distilled water. The pH was again measured at 7, 14, 21 and 28 days (pH2). The initial and final pH readings (pH1 and pH2) were compared by ANOVA, ANOVA2 and Tukey's tests (P < 0.05). Results The pH1 and pH2 measurements increased with time. The measurements obtained after retreatment were significantly higher than those obtained before root canal filling. Conclusions Hydroxyl ions are able to diffuse through dentinal tubules. Regardless of the filling material, it was possible to re-establish the permeability of dentine to ionic diffusion after retreatment. Time had a positive influence on ionic diffusion.
Endodontic Topics, 2006
Calcium hydroxide [Ca(OH) 2 ], when used as a root canal dressing, has been shown to promote periapical healing, induce formation of an apical hard tissue barrier (apexification), and arrest infection-related root resorption. The main mechanism of action is thought to be the high alkalinity of Ca(OH) 2 ensuring a bactericidal or bacteriostatic effect upon microorganisms in the root canal and dentinal tubules. Several anatomical factors related to the root canal, such as the coronal access cavity, the apical foramen, the dentinal tubules, and existing resorption cavities on the root surface, all allow leakage of hydroxide ions from the root canal. The purpose of the present clinical study was to analyze pH changes in 63 permanent anterior teeth in which Ca(OH) 2 (Calasept s ) was used as an initial canal dressing after replantation and subsequent pulp necrosis had developed. The pH changes in the pulp canal were studied with relation to observation period, stage of root formation, healing of any periapical radiolucency, infection-related root resorption, formation of an apical hard tissue barrier, and finally the radiographic appearance of Ca(OH) 2 in the canal (i.e. present or not). The study showed that several factors determined the pH level: the observation period (i.e. observation periods exceeding 6 months showed a significant drop in pH level below a pH of 10), an initial active inflammatory root resorption (tendency to be related to a drop in pH), and a subsequent progression of infection-related resorption (the same tendency to be related to a drop in pH to below 10). The size of the apical foramen and the length of the pulp had no relation to pH change. The radiographic disappearance of Ca(OH) 2 in the root canal (loss of radiopacity of the canal dressing) was found to be significantly associated with a drop in pH (P 5 0.001). It was concluded that radiographic monitoring of the Ca(OH) 2 presence in the root canal is essential for endodontic treatment planning (i.e. when to replace Ca(OH) 2 or perform a permanent root filling). Furthermore, continuous activity of inflammatory root resorption may indicate a drop in pH and should result in replacement of new Ca(OH) 2 . It should be noted that these findings apply to a Ca(OH) 2 product (Calasept s ) with no added radiopaque material.
Evaluation of the diffusion capacity of calcium hydroxide pastes through the dentinal tubules
Brazilian Oral Research, 2009
This study aimed to evaluate the diffusion capacity of calcium hydroxide pastes with different vehicles through dentinal tubules. The study was conducted on 60 extracted single-rooted human teeth whose crowns had been removed. The root canals were instrumented and divided into 4 groups according to the vehicle of the calcium hydroxide paste: Group I-distilled water; Group II-propylene glycol; Group III-0.2% chlorhexidine; Group IV-2% chlorhexidine. After placement of the root canal dressings, the teeth were sealed and placed in flasks containing deionized water. After 1, 2, 7, 15, 30, 45 and 60 days, the pH of the water was measured to determine the diffusion of calcium hydroxide through the dentinal tubules. The data were recorded and statistically compared by the Tukey test. The results showed that all pastes presented a similar diffusion capacity through dentin. Group IV did not present difference compared to group I. Group II presented difference compared to the other groups, as did Group III. In conclusion, groups I and IV presented a better diffusion capacity through dentin than groups II and III; 2% chlorhexidine can be used as a vehicle in calcium hydroxide pastes.
Materials
Calcium hydroxide's anti-bacterial action relies on high pH. The aim here was to investigate hydroxyl ion diffusion through dentine under different conditions. Teeth were divided into control (n = 4) and four experimental groups (n = 10): Group 1-no medicament; Group 2-Calmix; Group 3-Calmix/Ledermix; Group 4-Calasept Plus/Ledermix; Group 5-Pulpdent/smear layer. Deep (inner dentine) and shallow (outer dentine) cavities were cut into each root. pH was measured in these cavities for 12 weeks. The inner and outer dentine pH in Group 2 was significantly higher than all groups. Inner dentine pH in Group 3 was slightly higher than that in Group 4 initially but subsequently comparable. After Day 2, Group 5 had significantly lower pH than Groups 3 and 4. The outer dentine pH in Group 3 started higher than that in Groups 4 and 5, but by Day 28 the difference was insignificant. The time for the inner dentine to reach maximum pH was one week for Group 2 and four weeks for Groups 3 and 4. The time for the outer dentine to reach maximum pH was eight weeks for all experimental groups. Mixing different Ca(OH) 2 formulations with Ledermix gave similar hydroxyl ion release but pH and total diffusion was lower than Ca(OH) 2 alone. The smear layer inhibited diffusion.
pH changes and calcium ion diffusion from calcium hydroxide dressing materials through root dentin
Journal of Endodontics, 1999
The purpose of this study was to evaluate Ca 2+ and OH-diffusion properties through root dentin by using different calcium hydroxide (CH) dressing materials. Twenty-eight single-rooted teeth were instrumented and external defects were created on the root surface. 17% EDTA was used to eliminate the smear layer. All surfaces except the external defects were sealed, and the teeth were placed in normal saline. Ca 2÷ concentrations and the pH in the saline were determined for 3 days as the control period. After removing the teeth from normal saline, they were filled with: (i) DT Temporary Dressing CH; (ii) CH powder and normal saline; (iii) TempCanal; and (iv) CH points. The teeth were then placed in normal saline, and Ca 2+ concentrations and pH values were measured at 1, 3, 7, 14, and 28 days. Nonsetting CH pastes gradually released Ca 2+, whereas this increase was absent from CH points. None of the test materials induced a pH increase in the media during the observation period. This study demonstrated that, when nonsetting CH pastes are applied to the root canal, diffusion of Ca 2+ without an increase in pH to the surrounding media occurs. This implies that these type of material are more suitable than CH points for treatment of external root resorption.
European journal of dentistry, 2013
This study determined environmental pH changes after root canal dressing using 3 types of commercial calcium hydroxide pastes. Thirty-two extracted single-rooted human premolars with 1 straight root canal were selected. Standard cavities were prepared on root surfaces. All root surfaces, excluding the cavities, were covered with nail polish. Root canals were prepared using the Easy RaCe rotary system. The teeth were randomly divided into 3 experimental groups filled with calcium hydroxide pastes: (Group 1) Sure-Paste, (Group 2) Meta-Paste, and (Group 3) Multi-Cal. The control group had 2 samples. Teeth were then placed in 10 mL of normal saline. Environmental pH values were measured at 1 h, 24 h, 48 h, and 1 week. Statistical evaluations of the results were performed via the ANOVA and Tukey tests. Results demonstrated that groups 3 and 1 showed a significant statistical difference (P<.001) with the pH being greater in group 3. There was no significant difference between groups 2 ...
Effect of Irrigants and Cementum Injury on Diffusion of Hydroxyl Ions through the Dentinal Tubules
Journal of Endodontics, 2008
This study measured hydroxyl ion diffusion through dentinal tubules into a bathing solution. Eighty singlecanal, 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 Ͻ .001). With Tukey multiple comparisons, post-defect pH for group 6 was found to be significantly greater (P Ͻ .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.