Effect of calcium hydroxide on bacterial lipopolysaccharide

Safavi, Kamran E.; Nichols, Frank C.

doi:10.1016/s0099-2399(06)81199-4

Cited by 237 publications

(206 citation statements)

References 17 publications

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“…Significant elevations in PIP following prolonged steep Trendelenburg position is consistent with findings in other studies [6,10,12,21] and may be dependent upon the type of ventilation used (volume vs. pressure control) [22]. Subjecting the patient to steep head-down tilt causes compression of the thoracic cavity by exacerbating the pneumoperitoneum-induced cephalad displacement of the diaphragm and abdominal contents.…”

Section: Discussionsupporting

confidence: 85%

Cardiopulmonary Effects of Trendelenburg Positioning in Robotic Assisted Radical Cystectomy

Winters¹

2016

OAJUN

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Section: Discussionsupporting

confidence: 85%

Cardiopulmonary Effects of Trendelenburg Positioning in Robotic Assisted Radical Cystectomy

Winters¹

2016

OAJUN

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“…Recently, Safavi and Nichols (14) reported that, in vitro, calcium hydroxide hydrolyzes lipid A, which is the toxic component of the endotoxin; they also concluded that after lipid A hydrolysis, this potent toxic agent is converted to fatty acids and amino sugars that are not toxic (15). Barthel et al (4) and Olsen et al (16) also observed that calcium hydroxide could detoxify bacterial LPS in vitro.…”

Section: Discussionmentioning

confidence: 99%

“…Safavi and Nichols (14,15), Barthel et al (4), and Olsen et al (16) studied, in vitro, the effect of calcium hydroxide on bacterial LPS, because LPS may remain in the root canals between intracanal dressing sessions. However, there are no in vivo studies reporting this problem.…”

mentioning

confidence: 99%

Effect of Calcium Hydroxide on Bacterial Endotoxin In Vivo

Silva

Filho

Leonardo

et al. 2002

Journal of Endodontics

112

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The aim of this study was the histopathological evaluation of apical and periapical tissues in dog teeth that were submitted to bacterial endotoxin, associated or not with calcium hydroxide. After removal of the pulp from 60 premolars, the teeth were divided into four groups and were filled with bacterial endotoxin (group 1), bacterial endotoxin plus calcium hydroxide (group 2), saline solution (group 3), or had induced periapical lesions with no treatment (group 4). After 30 days, animals were killed and the teeth processed histologically. The inflammatory infiltrate, the thickness of the periodontal ligament, and the presence of resorption areas were similar for groups 1 and 4. Groups 2 and 3 were similar to each other. It can be concluded that the bacterial endotoxin caused a periapical lesion and that calcium hydroxide detoxified the lipopolysaccharides in vivo.Improvement in microbiology techniques for culture and identification has shown that root canals in teeth with pulp necrosis and a chronic periapical reaction have a predominance of anaerobic microorganisms (1, 2), especially Gram-negative ones (3). This polybacterial infection is present not only in the lumen of the root canal and dentinal tubules, but also in the apical craters and the entire root canal system (2). Gram-negative microorganisms not only have different virulent factors and produce toxic products and sub-products in apical and periapical tissues, but also contain endotoxin in their cell wall. Endotoxin, which consists of lipopolysaccharides (LPS), is liberated during bacterial cell multiplication or death and is responsible for a series of important biological effects (4, 5). Its action on macrophages (6) triggers the release of a series of inflammatory, bioactive, chemical mediators, or cytokines (5), such as tumor necrosis factor (TNF) (4, 5) and interleukins-1 (5, 7), -6, and -8 (7). Endotoxin also induces fever (8), is mitogenic to B lymphocytes (5), activates the complement system (8) and the metabolism of arachidonic acid (5), and irreversibly adheres to mineralized tissues. These events lead to an inflammatory reaction and bone resorption in the periapical region. These facts emphasize the important role of LPS in the pathogenesis of periapical lesions (4, 9, 10, 11).A survey of the medical literature over the last 10 yr produced 22,450 articles dealing with endotoxin; however only four articles in dentistry (9, 10, 12, 13) evaluated the effects of LPS on apical and periapical tissues using experimental animals.Treatment of root canals in teeth with pulp necrosis and a chronic periapical reaction should not only be concerned with bacterial death, but also the inactivation of endotoxin. Safavi and Nichols (14, 15), Barthel et al. (4), and Olsen et al. (16) studied, in vitro, the effect of calcium hydroxide on bacterial LPS, because LPS may remain in the root canals between intracanal dressing sessions. However, there are no in vivo studies reporting this problem.The purpose of this study was to evaluate histopathologically the ef...

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“…Another factor that may corroborate the results obtained in this study is the ephemeral ozone gas half-life. 24 The only techniques that have been tested so far and have showed a certain degree of effectiveness against LPS are (a) the use of calcium hydroxide as an intra-canal medication 12,25,26 as it hydrolyses lipid A and changes it into chains of fatty acid and nontoxic sugars, 27 and (b) the application of laser Nd:YAG. 9 The results obtained in this study reinforce the importance of instrumentation in addition to any disinfection protocol, 11,28,29 especially with regard to bacterial LPS that strongly adheres to the dentinal wall 6 and makes it necessary to use endodontic instruments for its removal.…”

Section: Discussionmentioning

confidence: 99%

LPS levels in root canals after the use of ozone gas and high frequency electrical pulses

et al. 2016

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The present study aims to verify the effect of ozone gas (OZY ® System) and high frequency electric pulse (Endox ® System) systems on human root canals previously contaminated with Escherichia coli lipopolysaccharide (LPS). Fifty single-rooted teeth had their dental crowns removed and root lengths standardized to 16 mm. The root canals were prepared up to #60 hand K-files and sterilized using gamma radiation with cobalt 60. The specimens were divided into the following five groups (n = 10) based on the disinfection protocol used: OZY ® System, one 120-second-pulse (OZY 1p); OZY ® System, four 24-second-pulses (OZY 4p); and Endox ® System (ENDOX). Contaminated and non-contaminated canals were exposed only to apyrogenic water and used as positive (C+) and negative (C-) controls, respectively. LPS (O55:B55) was administered in all root canals except those belonging to group C-. After performing disinfection, LPS samples were collected from the canals using apyrogenic paper tips. Limulus Amoebocyte Lysate (LAL) was used to quantify the LPS levels, and the data obtained was analyzed using one-way ANOVA. The disinfection protocols used were unable to reduce the LPS levels significantly (p = 0.019). The use of ozone gas and high frequency electric pulses was not effective in eliminating LPS from the root canals.

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Effect of calcium hydroxide on bacterial lipopolysaccharide

Cited by 237 publications

References 17 publications

Cardiopulmonary Effects of Trendelenburg Positioning in Robotic Assisted Radical Cystectomy

Cardiopulmonary Effects of Trendelenburg Positioning in Robotic Assisted Radical Cystectomy

Effect of Calcium Hydroxide on Bacterial Endotoxin In Vivo

LPS levels in root canals after the use of ozone gas and high frequency electrical pulses

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