Organic Tissue Dissolution in Clodronate and Etidronate Mixtures with Sodium Hypochlorite

The addition of Dual Rinse HEDP, an etidronate powder, to a sodium hypochlorite (NaOCl) solution can create a combined single endodontic irrigant with a soft tissue-dissolving and a decalcifying effect, which can replace traditional alternating irrigation with chemically non-compatible solutions. While the short-term compatibility between NaOCl and 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) has been shown, it remains unclear whether ultrasonic activation of a combined NaOCl & HEDP solution immediately reduces the available chlorine and/or renders the NaOCl ineffective in dissolving organic tissue remnants. This was tested in three experiments: (1) direct activation in test tubes in an ultrasonic bath and then the activation by an ultrasonically oscillating tip (IrriSafe) in (2) an epoxy resin model containing a simulated isthmus filled with gelatin, and (3) extracted teeth with simulated resorption cavities filled with soft tissue. The control solutions were physiological saline and 2.5% NaOCl without HEDP. In (1), available chlorine after 30 s of ultrasonic activation (37 kHz) of test and control solution was assessed, as well as shrimp tissue weight loss in direct exposure. In (2) and (3), the ultrasonic tip was driven at 1/3 of full power using the respective unit, and areas of removed gelatin from the isthmus and tissue weight loss were used as the outcomes, respectively. Experiment (1) revealed no negative impact by HEDP on available chlorine (1), while all three experiments showed a highly significant (p > 0.001) synergistic effect, which was not hampered by HEDP, between NaOCl and ultrasonic activation regarding tissue weight loss (1, 3) and dissolution of gelatin (2).

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Analysis of root canal organic tissue dissolution capacity according to the type of irrigation solution and agitation technique

Brazilian Journal of Oral Sciences ◽

10.20396/bjos.v15i1.8647128 ◽

2016 ◽

Vol 15 (1) ◽

pp. 70

Author(s):

Kiany Scarssi Nunes ◽

Letícia Feron ◽

Francisco Montagner ◽

Tiago André Fontoura de Melo

Keyword(s):

Sodium Hypochlorite ◽

Root Canal ◽

Nonparametric Test ◽

Distilled Water ◽

Chlorhexidine Digluconate ◽

Pulp Tissue ◽

Mechanical Agitation ◽

Significance Level ◽

Average Percentage ◽

Organic Tissue

Aim: To analyze the root canal organic tissue dissolution capacity promoted by irrigating solutions, with or without the use of different agitation techniques. Methods: Bovine pulp tissue fragments were initially weighed. The following irrigating solutions were tested: 2.5% sodium hypochlorite, 2% chlorhexidine digluconate solution, and distilled water. The irrigating protocols were: immersion, mechanical agitation with endodontic files, and ultrasonic or sonic systems (Endoactivactor® and Easy Clean®). At the end of the protocols, the pulps were weighed to determine their final weight. For comparison, the average percentage of tissue dissolution in relation to the groups was analyzed using the Kruskal-Wallis nonparametric test complemented by multiple comparisons test. The significance level was set at 5%. Results: Among the irrigation solutions, 2.5% sodium hypochlorite showed a higher dissolving power than 2% chlorhexidine digluconate and distilled water. Furthermore, ultrasonic and sonic systems were more effective irrigating protocols than immersion and mechanical agitation with endodontic files. Conclusions: The combination of sodium hypochlorite with an agitation system promotes a greater degree of tissue degradation.

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Comparison of Acrylamide and Agar Gels by Freeze-Etching

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100080456 ◽

1977 ◽

Vol 35 ◽

pp. 606-607

Author(s):

Russell L. Steere ◽

Eric F. Erbe

Keyword(s):

Electron Microscope ◽

Sodium Hydroxide ◽

Sodium Hypochlorite ◽

Chromic Acid ◽

Distilled Water ◽

Thin Sheets ◽

Acid Cleaning ◽

Agar Gels ◽

Freeze Etching ◽

Water Cut

Thin sheets of acrylamide and agar gels of different concentrations were prepared and washed in distilled water, cut into pieces of appropriate size to fit into complementary freeze-etch specimen holders (1) and rapidly frozen. Freeze-etching was accomplished in a modified Denton DFE-2 freeze-etch unit on a DV-503 vacuum evaporator.* All samples were etched for 10 min. at -98°C then re-cooled to -150°C for deposition of Pt-C shadow- and C replica-films. Acrylamide gels were dissolved in Chlorox (5.251 sodium hypochlorite) containing 101 sodium hydroxide, whereas agar gels dissolved rapidly in the commonly used chromic acid cleaning solutions. Replicas were picked up on grids with thin Foimvar support films and stereo electron micrographs were obtained with a JEM-100 B electron microscope equipped with a 60° goniometer stage.Characteristic differences between gels of different concentrations (Figs. 1 and 2) were sufficiently pronounced to convince us that the structures observed are real and not the result of freezing artifacts.

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Freeze-Etch Crystal-Like Structures in Membranous Glomerulosclerosis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063883 ◽

1969 ◽

Vol 27 ◽

pp. 394-395

Author(s):

Burton B. Silver

Keyword(s):

Electron Microscopy ◽

Light Microscopy ◽

Sodium Hypochlorite ◽

Kidney Tissue ◽

Extraction Process ◽

Donor Kidney ◽

Unknown Substance ◽

Etched Surface ◽

Standard Fixation ◽

Diseased Kidney

Tissue from a non-functional kidney affected with chronic membranous glomerulosclerosis was removed at time of trnasplantation. Recipient kidney tissue and donor kidney tissue were simultaneously fixed for electron microscopy. Primary fixation was in phosphate buffered gluteraldehyde followed by infiltration in 20 and then 40% glycerol. The tissues were frozen in liquid Freon and finally in liquid nitrogen. Fracturing and replication of the etched surface was carried out in a Denton freeze-etch device. The etched surface was coated with platinum followed by carbon. These replicas were cleaned in a 50% solution of sodium hypochlorite and mounted on 400 mesh copper grids. They were examined in an Siemens Elmiskop IA. The pictures suggested that the diseased kidney had heavy deposits of an unknown substance which might account for its inoperative state at the time of surgery. Such deposits were not as apparent in light microscopy or in the standard fixation methods used for EM. This might have been due to some extraction process which removed such granular material in the dehydration steps.

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