Microscopic cleanliness evaluation of the apical root canal after using calcium hydroxide mixed with chlorhexidine, propylene glycol, or antibiotic paste

The Effectiveness of Different Final Irrigation Protocols for Removal of Calcium Hydroxide Intracanal Medication from Root Canal

Calcium hydroxide is the most used intracanalar medicament between apointments. It shoud be properly removed before root canal filling because its remnants could compromise the sealing of root obturation. The aim of this study was to compare the effectiveness of two type of irrigation solutions, EDTA and SmearClear in the removal of calcium hydroxide from root canals. Materials and method: twenty human single rooted teeth were prepared using ProTaper Universal instrumentation till F2, .06 taper. The canals were filled with Ca(OH)2 and after 7 days the Ca(OH)2 was removed using 3 rinses of 5 ml 15% EDTA and 5 ml 5.25% NaOCl alternately (group 1; n=10) or 3 rinses of 5 ml Smear Clear (SybronEndo) and 5 ml 5.25% NaOCl alternately (group 2; n=10). Results: On the final radiographs the best result was found in group 2 where the cleanliness of the total surface of the root canal wall when SmearClear was used obtained better results comparative to NaOCl – 15% EDTA (91.34% to 71.69%). Conclusions: under the limitation of this study, SmearClear was superior in removing Ca(OH)2 material compared to NaOCl and 15% EDTA irrigation solution.

Evaluating the efficacy of different techniques and irrigation solutions for removal of calcium hydroxide from the root canal system: A scanning electron microscope study

Aim:

The aim of this scanning electron microscope study was to compare the efficacy of two techniques (EndoVac and EndoActivator) and two irrigating solutions (5.25% NaOCl in combination with 17% ethylenediaminetetraacetic acid vs. Savlon™) for removal of calcium hydroxide (CH) from the root canal walls.

Settings and Design:

The study was carried out in the specialty of conservative dentistry and endodontics.

Materials and Methods:

Forty single-canal human teeth were used. The specimens were de-coronated to obtain a standardized root length of 15 mm using a diamond disk. The canals were instrumented till F3 ProTaper and CH intracanal medicament placed in the root canal. One week later, teeth were randomly divided into one control group and six experimental groups according to different irrigation protocols with different techniques.

Statistical Analysis:

Kruskal–Wallis test was conducted to analyze the effect of different treatment measures with respect to three regions of tooth.

Results:

The results indicated that there was no statistically significant difference between the two irrigation solutions and two techniques.

Conclusion:

To achieve the best adaptation of filling material after root canal treatment, it is crucial to remove intracanal medication from the root canal walls. However, none of the irrigation regimens and different techniques were able to completely remove the CH from the root canal wall.

Efeito da medicação intracanal na resistência de união de um cimento obturador endodôntico à dentina radicular

Objetivo: Este estudo teve como objetivo avaliar a influência da medicação intracanal na resistência de união de um cimento obturador endodôntico à dentina radicular. Métodos: Foram utilizadas 24 raízes bovinas unirradiculares que foram submetidas ao preparo químico-cirúrgico e divididas aleatoriamente em 4 grupos da seguinte forma: G1, (controle), sem medicação; G2, Hidróxido de Cálcio (Ca(OH)2) + Clorexidina (CHX); G3, bolinha de algodão embebida em Formocresol; e, G4, bolinha de algodão embebida em Paramonoclorofenol Canforado. As amostras ficaram armazenadas em temperatura ambiente e 100% de umidade por 1 semana. Logo após, foram obturadas com cimento endodôntico AH Plus e cones de guta-percha. Os dentes foram então fatiados transversalmente e o teste de push-out foi realizado. Os dados foram tabulados e submetidos à Análise de Variância. Resultados: As médias e seus respectivos desvios-padrão foram: G1, 2,42 (±1,45) ; G2, 1,81 (±1,04); G3, 2,21 (±1,14); e, G4, 2.63 (±1.32). Os resultados mostraram que não houve diferença estatisticamente significante entre os grupos em estudo. Conclusão: Pode-se concluir que as medicações intracanal utilizadas neste estudo não influenciaram na resistência de união do cimento obturador AH Plus à dentina radicular.

Removal efficacy and cytotoxicity of a calcium hydroxide paste using N-2-methyl-pyrrolidone as a vehicle

Objectives

This study investigated the removal efficacy and cytotoxicity of a newly developed calcium hydroxide paste (cleaniCal, Maruchi) using N-2-methyl-pyrrolidone (NMP) as a vehicle in comparison with ApexCal (Ivoclar Vivadent) and Calcipex II (Nishika), which use different vehicles such as polyethylene glycol and propylene glycol, respectively.

Materials and Methods

Thirty maxillary premolars with oval-shaped canals were divided into 3 groups and the teeth were filled with one of the pastes. After removal of the paste, micro-computed tomographic (μ-CT) imaging was obtained to assess the volume of residual paste in the root canal of each tooth. The teeth were then split longitudinally and the area of the paste-coated surface was evaluated by stereomicroscopy. The cytotoxicity of each product was assessed using an agar overlay assay. The effect of each vehicle on cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The data were analyzed using one-way analysis of variance and Tukey's tests to detect any significance (p < 0.05).

Results

In the μ-CT and stereomicroscopic analysis, cleaniCal exhibited less remnants of medicament than ApexCal and Calcipex. cleaniCal showed a higher cytotoxicity than the other pastes in the agar overlay assay. Furthermore, NMP exhibited lower cell viability compared to the other vehicles.

Conclusions

cleaniCal showed better removal efficacy compared to the other products. However, clinicians should be aware of the higher cytotoxicity of the NMP-based material and consider its possible adverse effects on periradicular tissue when it is overfilled.

Retrievabilty of calcium hydroxide intracanal medicament with Chitosan from root canals: An in vitro CBCT volumetric analysis

AIM

This study compared the amount of aqueous-based and oil-based calcium hydroxide [Ca(OH)2 ] remaining in the canal, after removal with two different chelators 17% EDTA and 0.2% Chitosan in combination with ultrasonic agitation.

MATERIALS AND METHODS

Cleaning and shaping of root canals of 28 mandibular premolar was done and canals were filled either with Metapex or Ca(OH)2 mixed with distilled water. Volumetric analysis was performed utilizing cone beam-computed tomography (CBCT) after 7 days of incubation. Ca(OH)2 was removed using either 17% EDTA or 0.2% Chitosan in combination with ultrasonic agitation. Volumetric analysis was repeated and percentage difference was calculated and statistically analysed using Kruskal-Wallis and Mann-Whitney U test.

RESULTS

Both the chelators failed to remove aqueous-based as well as oil-based Ca(OH)2 completely from the root canal. Aqueous-based Ca(OH)2 was easier to be removed than oil-based Ca(OH)2. 0.2% Chitosan was significantly more effective for removal of oil-based Ca(OH)2 (P < 0.01) while both 17% EDTA and 0.2% Chitosan were equally effective in removing aqueous-based Ca(OH)2 .

CONCLUSION

Combination of 0.2% Chitosan and ultrasonic agitation results in lower amount of Ca(OH)2 remnants than 17% EDTA irrespective of type of vehicle present in the mix.

Strontium-incorporated mesoporous bioactive glass scaffolds stimulating in vitro proliferation and differentiation of bone marrow stromal cells and in vivo regeneration of osteoporotic bone defects

Osteoporosis is one of the most widely occurring bone disorders characterized by low bone mineral density and poor bone strength. Strontium ranelate, as a treatment option, has received significant attention in recent years due to its ability to halt the progress of osteoporosis by simultaneously improving bone formation and reducing bone resorption. Although much emphasis has been given to the treatment of osteoporosis and fracture prevention using pharmacological agents, much less attention has been placed on the repair of critical-sized bone fractures caused by osteoporosis. The aim of the present study was to prepare strontium-incorporated mesoporous bioactive glass (Sr-MBG) scaffolds in order to combine the therapeutic effects of Sr²⁺ ions on osteoporosis with the bioactivity of MBG to regenerate osteoporotic-related fractures. Prior to animal implantation, the effects of Sr-containing ionic products from Sr-MBG scaffolds on the proliferation and differentiation of bone marrow stromal cells (BMSCs) from osteoporotic bone were investigated in an in vitro culture system. The results showed that Sr-MBG scaffolds significantly increased the proliferation of BMSCs in a concentration dependent manner and were able to stimulate the expression of osteoblast differentiation markers including Alpl, Col1a1, Runx2 and Bglap as assessed by real-time PCR. Critical sized femur defects in ovariectomised rats were created to simulate an osteoporotic phenotype. At time points 2, 4 and 8 weeks post-implantation, the in vivo osteogenetic efficiency was systematically evaluated by μCT analysis, hematoxylin and eosin staining, and immunohistochemistry (type I collagen). The results showed that the incorporation of Sr into MBG scaffolds significantly stimulated new bone formation in osteoporotic bone defects when compared to MBG scaffolds alone. Furthermore, it was generally found that Sr release in blood was maintained at a very low level and the Sr, Si, Ca and P excretion by urine operated in an a similar manner to blank control animals. Our results suggested that Sr-MBG scaffolds could be a promising biomaterial for regenerating osteoporosis-related fractures by the release of Sr-containing ionic products.

Comparative antimicrobial efficacy of Metapex, Metronidazole, BioPure MTAD, Aztreonam on Bacteroides fragilis and Propionibacterium acne

Aim:

The purpose of this study was to evaluate the comparative antibacterial efficacy of Biopure MTAD, Metapex, Metronidazole, and Aztreonam against two obligate anerobic bacteria.

Materials and Methods:

Antimicrobial efficacy of selected medicaments against two obligate anaerobic bacteria Bacteroides fragilis and Propionibacterium acnes was done by Agar disc-diffusion method. Pre-sterilized Whatman paper discs, 6 mm in diameter and soaked with the test solution, were prepared and placed onto the previously seeded agar Petri plates. Each plate was incubated in anaerobic jar for anerobic environment at 37°C for 48 hours. A zone of inhibition was recorded for each plate and the results were analysed statistically. Saline and ethanol used as control group in this study.

Results:

Biopure MTAD, Metapex and Metronidazole were effective against all the selected microorganisms. Aztreonam was effective against Bacteroides fragilis. Saline and ethanol used as control were ineffective.

Conclusions:

Metronidazole showed the superior antibacterial property amongst the tested medicaments.

Relationship between sealing ability of Activ GP and Gutta Flow and methods of calcium hydroxide removal

Aim:

To evaluate the effect of method of calcium hydroxide intracanal dressing removal, on sealing ability of Gutta Flow and Activ GP.

Materials and Methods:

Seventy extracted mandibular premolars were sectioned at CEJ and canals were prepared with profile 4% rotary file till #40. Canals were filled with calcium hydroxide, coronally sealed with Cavit G and stored at 37°C. After 7 days, samples were divided on the basis of calcium hydroxide removal method (Master apical file, Navi Tip FX, and F File) and obturating material (Activ GP and Gutta Flow). Three coats of nail polish were applied except 2 mm around apical foramen and samples were immersed in India ink dye, sectioned, and observed under stereomicroscope for microleakage.

Results:

The results were statistically analyzed with one way ANOVA-F with Tukey HSD test with the null hypothesis set as 5%.

Conclusions:

The seal of the canal system was adversely impacted by residual calcium hydroxide when Activ GP and Gutta Flow were used as obturating material and the sealing ability of Activ GP and Gutta Flow was better when MAF was used for removal of calcium hydroxide than F file or Navi tip FX.

Efficacy of the NaviTip FX irrigation needle in removing calcium hydroxide from root canal

OBJECTIVE

To evaluate the effectiveness of the NaviTip FX, brush-covered irrigation needle, in removing calcium hydroxide from the root canal.

STUDY DESIGN

Thirty single-rooted teeth were randomly divided into three groups: A - irrigation with a hypodermic needle inserted as far as possible without binding and activation with #30 K-type file; B - Irrigation with a hypodermic needle without activation; C - irrigation with NaviTip FX needle. Sodium hypoclorite 1% was used in irrigation. The root canals were examined trough scanning electron microscopy. Calcium hydroxide removal was recorded at 1, 5, and 10mm from the working length (WL) and the data were analysed using one-way ANOVA test (p<0.05).

RESULTS

NaviTip FX and hypodermic needle activated with #30K-type file showed lower score at 10 and 5mm with no significant difference between them. Comparison within groups did not show significant differences. All groups showed significantly better smear layer removal at 5 and 10 mm from the WL.

CONCLUSION

The apical third (1mm) of the root canal was found to be the most critical site for Ca(OH)2 removal. Key words:Calcium hydroxide, irrigation, scanning electron microscope, NaviTip FX.