MyMedR

Displaying publications 61 - 64 of 64 in total

Abstract:

Sort:

Fulltext Biofilm in endodontics: A review

Jhajharia K, Parolia A, Shetty KV, Mehta LK

J Int Soc Prev Community Dent, 2015 Jan-Feb;5(1):1-12.
PMID: 25767760 DOI: 10.4103/2231-0762.151956

Endodontic disease is a biofilm-mediated infection, and primary aim in the management of endodontic disease is the elimination of bacterial biofilm from the root canal system. The most common endodontic infection is caused by the surface-associated growth of microorganisms. It is important to apply the biofilm concept to endodontic microbiology to understand the pathogenic potential of the root canal microbiota as well as to form the basis for new approaches for disinfection. It is foremost to understand how the biofilm formed by root canal bacteria resists endodontic treatment measures. Bacterial etiology has been confirmed for common oral diseases such as caries and periodontal and endodontic infections. Bacteria causing these diseases are organized in biofilm structures, which are complex microbial communities composed of a great variety of bacteria with different ecological requirements and pathogenic potential. The biofilm community not only gives bacteria effective protection against the host's defense system but also makes them more resistant to a variety of disinfecting agents used as oral hygiene products or in the treatment of infections. Successful treatment of these diseases depends on biofilm removal as well as effective killing of biofilm bacteria. So, the fundamental to maintain oral health and prevent dental caries, gingivitis, and periodontitis is to control the oral biofilms. From these aspects, the formation of biofilms carries particular clinical significance because not only host defense mechanisms but also therapeutic efforts including chemical and mechanical antimicrobial treatment measures have the most difficult task of dealing with organisms that are gathered in a biofilm. The aim of this article was to review the mechanisms of biofilms' formation, their roles in pulpal and periapical pathosis, the different types of biofilms, the factors influencing biofilm formation, the mechanisms of their antimicrobial resistance, techniques to identify biofilms.

Matched MeSH terms: Disinfectants
Performance of chlorination process during nanofiltration of sulfonamide antibiotic

Ramli MR, Sulaiman NM, Mohd MA, Rabuni MF

Water Sci Technol, 2015;72(9):1611-20.
PMID: 26524453 DOI: 10.2166/wst.2015.367

The effectiveness of combined nanofiltration and disinfection processes was studied by comparing the pre-disinfection and post-disinfection when in combination with nanofiltration. Four types of sulfonamide (sulfanilamide, sulfadiazine, sulfamethoxazole, and sulfadimethoxine) were chosen as substrates, with sodium hypochlorite as a disinfectant. A laboratory-scale nanofiltration system was used to conduct the following sets of experiment: (1) a pre-chlorination system, where the free active chlorine (FAC) was added to the membrane influent; and (2), a post-chlorination system, where the FAC was added to the membrane effluent. Overall, the pre-disinfection nanofiltration system showed higher sulfonamide removal efficiency compared to the post-chlorination nanofiltration system (>99.5% versus >89.5%). In the case of limited FAC ([FAC]0: [sulfonamide]0≤1), the removal efficiency for the post-chlorination nanofiltration system was higher, due to the prior nanofiltration process that could remove 12.5% to 80% of sulfonamide. The flux of the treated feed system was considerably higher than in the untreated feed system; however, the membrane was observed to be slightly damaged due to residual chlorine attack.

Matched MeSH terms: Disinfectants
Fulltext A quaternary ammonium silane antimicrobial triggers bacterial membrane and biofilm destruction

Daood U, Matinlinna JP, Pichika MR, Mak KK, Nagendrababu V, Fawzy AS

Sci Rep, 2020 07 03;10(1):10970.
PMID: 32620785 DOI: 10.1038/s41598-020-67616-z

To study the antimicrobial effects of quaternary ammonium silane (QAS) exposure on Streptococcus mutans and Lactobacillus acidophilus bacterial biofilms at different concentrations. Streptococcus mutans and Lactobacillus acidophilus biofilms were cultured on dentine disks, and incubated for bacterial adhesion for 3-days. Disks were treated with disinfectant (experimental QAS or control) and returned to culture for four days. Small-molecule drug discovery-suite was used to analyze QAS/Sortase-A active site. Cleavage of a synthetic fluorescent peptide substrate, was used to analyze inhibition of Sortase-A. Raman spectroscopy was performed and biofilms stained for confocal laser scanning microscopy (CLSM). Dentine disks that contained treated dual-species biofilms were examined using scanning electron microscopy (SEM). Analysis of DAPI within biofilms was performed using CLSM. Fatty acids in bacterial membranes were assessed with succinic-dehydrogenase assay along with time-kill assay. Sortase-A protein underwent conformational change due to QAS molecule during simulation, showing fluctuating alpha and beta strands. Spectroscopy revealed low carbohydrate intensities in 1% and 2% QAS. SEM images demonstrated absence of bacterial colonies after treatment. DAPI staining decreased with 1% QAS (p

Matched MeSH terms: Disinfectants/pharmacology
Fulltext Interventions to reduce contaminated aerosols produced during dental procedures for preventing infectious diseases

Kumbargere Nagraj S, Eachempati P, Paisi M, Nasser M, Sivaramakrishnan G, Verbeek JH

Cochrane Database Syst Rev, 2020 Oct 12;10(10):CD013686.
PMID: 33047816 DOI: 10.1002/14651858.CD013686.pub2

BACKGROUND: Many dental procedures produce aerosols (droplets, droplet nuclei and splatter) that harbour various pathogenic micro-organisms and may pose a risk for the spread of infections between dentist and patient. The COVID-19 pandemic has led to greater concern about this risk.
OBJECTIVES: To assess the effectiveness of methods used during dental treatment procedures to minimize aerosol production and reduce or neutralize contamination in aerosols.
SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases on 17 September 2020: Cochrane Oral Health's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (in the Cochrane Library, 2020, Issue 8), MEDLINE Ovid (from 1946); Embase Ovid (from 1980); the WHO COVID-19 Global literature on coronavirus disease; the US National Institutes of Health Trials Registry (ClinicalTrials.gov); and the Cochrane COVID-19 Study Register. We placed no restrictions on the language or date of publication.
SELECTION CRITERIA: We included randomized controlled trials (RCTs) and controlled clinical trials (CCTs) on aerosol-generating procedures (AGPs) performed by dental healthcare providers that evaluated methods to reduce contaminated aerosols in dental clinics (excluding preprocedural mouthrinses). The primary outcomes were incidence of infection in dental staff or patients, and reduction in volume and level of contaminated aerosols in the operative environment. The secondary outcomes were cost, accessibility and feasibility.
DATA COLLECTION AND ANALYSIS: Two review authors screened search results, extracted data from the included studies, assessed the risk of bias in the studies, and judged the certainty of the available evidence. We used mean differences (MDs) and 95% confidence intervals (CIs) as the effect estimate for continuous outcomes, and random-effects meta-analysis to combine data. We assessed heterogeneity.
MAIN RESULTS: We included 16 studies with 425 participants aged 5 to 69 years. Eight studies had high risk of bias; eight had unclear risk of bias. No studies measured infection. All studies measured bacterial contamination using the surrogate outcome of colony-forming units (CFU). Two studies measured contamination per volume of air sampled at different distances from the patient's mouth, and 14 studies sampled particles on agar plates at specific distances from the patient's mouth. The results presented below should be interpreted with caution as the evidence is very low certainty due to heterogeneity, risk of bias, small sample sizes and wide confidence intervals. Moreover, we do not know the 'minimal clinically important difference' in CFU. High-volume evacuator Use of a high-volume evacuator (HVE) may reduce bacterial contamination in aerosols less than one foot (~ 30 cm) from a patient's mouth (MD -47.41, 95% CI -92.76 to -2.06; 3 RCTs, 122 participants (two studies had split-mouth design); very high heterogeneity I² = 95%), but not at longer distances (MD -1.00, -2.56 to 0.56; 1 RCT, 80 participants). One split-mouth RCT (six participants) found that HVE may not be more effective than conventional dental suction (saliva ejector or low-volume evacuator) at 40 cm (MD CFU -2.30, 95% CI -5.32 to 0.72) or 150 cm (MD -2.20, 95% CI -14.01 to 9.61). Dental isolation combination system One RCT (50 participants) found that there may be no difference in CFU between a combination system (Isolite) and a saliva ejector (low-volume evacuator) during AGPs (MD -0.31, 95% CI -0.82 to 0.20) or after AGPs (MD -0.35, -0.99 to 0.29). However, an 'n of 1' design study showed that the combination system may reduce CFU compared with rubber dam plus HVE (MD -125.20, 95% CI -174.02 to -76.38) or HVE (MD -109.30, 95% CI -153.01 to -65.59). Rubber dam One split-mouth RCT (10 participants) receiving dental treatment, found that there may be a reduction in CFU with rubber dam at one-metre (MD -16.20, 95% CI -19.36 to -13.04) and two-metre distance (MD -11.70, 95% CI -15.82 to -7.58). One RCT of 47 dental students found use of rubber dam may make no difference in CFU at the forehead (MD 0.98, 95% CI -0.73 to 2.70) and occipital region of the operator (MD 0.77, 95% CI -0.46 to 2.00). One split-mouth RCT (21 participants) found that rubber dam plus HVE may reduce CFU more than cotton roll plus HVE on the patient's chest (MD -251.00, 95% CI -267.95 to -234.05) and dental unit light (MD -12.70, 95% CI -12.85 to -12.55). Air cleaning systems One split-mouth CCT (two participants) used a local stand-alone air cleaning system (ACS), which may reduce aerosol contamination during cavity preparation (MD -66.70 CFU, 95% CI -120.15 to -13.25 per cubic metre) or ultrasonic scaling (MD -32.40, 95% CI - 51.55 to -13.25). Another CCT (50 participants) found that laminar flow in the dental clinic combined with a HEPA filter may reduce contamination approximately 76 cm from the floor (MD -483.56 CFU, 95% CI -550.02 to -417.10 per cubic feet per minute per patient) and 20 cm to 30 cm from the patient's mouth (MD -319.14 CFU, 95% CI - 385.60 to -252.68). Disinfectants ‒ antimicrobial coolants Two RCTs evaluated use of antimicrobial coolants during ultrasonic scaling. Compared with distilled water, coolant containing chlorhexidine (CHX), cinnamon extract coolant or povidone iodine may reduce CFU: CHX (MD -124.00, 95% CI -135.78 to -112.22; 20 participants), povidone iodine (MD -656.45, 95% CI -672.74 to -640.16; 40 participants), cinnamon (MD -644.55, 95% CI -668.70 to -620.40; 40 participants). CHX coolant may reduce CFU more than povidone iodine (MD -59.30, 95% CI -64.16 to -54.44; 20 participants), but not more than cinnamon extract (MD -11.90, 95% CI -35.88 to 12.08; 40 participants).
AUTHORS' CONCLUSIONS: We found no studies that evaluated disease transmission via aerosols in a dental setting; and no evidence about viral contamination in aerosols. All of the included studies measured bacterial contamination using colony-forming units. There appeared to be some benefit from the interventions evaluated but the available evidence is very low certainty so we are unable to draw reliable conclusions. We did not find any studies on methods such as ventilation, ionization, ozonisation, UV light and fogging. Studies are needed that measure contamination in aerosols, size distribution of aerosols and infection transmission risk for respiratory diseases such as COVID-19 in dental patients and staff.

Matched MeSH terms: Disinfectants