The efficacy of 2780 nm Er,Cr;YSGG and 940 nm Diode Laser in root canal disinfection: A randomized clinical trial

OBJECTIVES

Effective disinfection of the root canals is the cornerstone of successful endodontic treatment. Diminishing the microbial load within the root canal system is crucial for healing in endodontically treated teeth. The aim of this study was to evaluate the effect of 2780 nm Er,Cr:YSGG and 940 nm diode lasers on the eradication of microorganisms from single-rooted teeth with asymptomatic apical periodontitis.

MATERIALS AND METHODS

Thirty participants conforming to the inclusion criteria were randomly divided into 3 groups according to the disinfection protocol used; Conventional group: 2.5% Sodium Hypochlorite (NaOCl) and 17% EDTA solution NaOCl/EDTA, Dual laser group: 2780 nm Erbium, chromium: yttrium scandium-gallium-garnet (Er,Cr:YSGG) laser and 940 nm diode laser Er,CrYSGG/Diode, and Combined group: 17% EDTA and 940 nm diode laser EDTA/Diode. Bacterial samples were collected before and after intervention. The collected data were statistically analyzed using Friedman's test and Kruskal-Wallis test (P ≤ 0.05).

RESULTS

The results of the study showed that both dual laser Er,CrYSGG/Diode and combined laser EDTA/Diode groups showed significantly less mean Log10 CFU/ml of aerobic and anaerobic bacterial counts than the conventional NaOCl/EDTA group.

CONCLUSIONS

In this study we evaluated in vivo the bactericidal efficacy of three disinfection protocols for endodontic treatment of single-rooted teeth with apical periodontitis. The results indicated that both dual laser Er,CrYSGG/Diode and combined laser EDTA/Diode groups provide superior bactericidal effect compared to the conventional NaOCl/EDTA group.

CLINICAL RELEVANCE

The integration of lasers into root canal disinfection protocols has demonstrated significant bacterial reduction which might promote healing and long-term success.

Clinical Manifestations and Stool Load of Atypical Enteropathogenic Escherichia coli Infections in United States Children and Adults

BACKGROUND & AIMS

There is debate whether atypical enteropathogenic Escherichia coli (aEPEC) causes disease in adults. aEPEC is commonly detected in symptomatic and asymptomatic individuals. aEPEC, in contrast to typical EPEC, lacks bundle-forming pili, altering its pathogenicity. Here, we define for the first time the clinical manifestations of sporadic aEPEC infection in United States children and adults and determine whether EPEC load correlates with disease.

METHODS

This is a retrospective case-control study of 380 inpatients/outpatients of all ages. EPEC load in stools was determined by quantitative polymerase chain reaction.

RESULTS

Diarrhea, vomiting, abdominal pain, and fever were more prevalent in EPEC-positive cases than in EPEC-negative controls. aEPEC infection caused mostly acute, mild diarrhea lasting for 6 to 13 days. However, some had severe diarrhea with 10 to 40 bowel movements per day or had persistent/chronic diarrhea. Fever, vomiting, and abnormal serum sodium levels were more common in children. Adults more often reported abdominal pain and longer duration of diarrhea. Symptomatic aEPEC infection was associated with leukocytosis in 24% of patients. EPEC load >0.1% was associated with symptomatic infection; however, loads varied greatly. Co-infecting pathogens did not alter diarrhea severity or EPEC load. Longitudinal data reveal that some are colonized for months to years or are repeatedly infected.

CONCLUSIONS

aEPEC is associated with a wide array of symptoms in adults, ranging from asymptomatic carriage to severe diarrhea. Higher EPEC loads are associated with presence of symptoms, but bacterial load does not predict disease or severity. Future studies are needed to understand bacterial and host factors that contribute to aEPEC pathogenicity to improve diagnostic tools and clinical care.

Suction Hoses of Dental Units as a Potential Source of Microbial Contamination

Objectives

Dental units are necessary tools for modern dentistry. Microbial contamination of dental units is thought to be the result of biofilm formation in various parts of the unit. We aimed to identify the total microbial count in the suction hose of dental units, and detect the presence of Pseudomonas aeruginosa.

Methods

Random sampling of suction hoses of dental units in Birjand, Iran, was performed in dental clinics on the first (n = 115) and last (n = 115) working days of the week. Total viable counts of bacteria and detection of P. aeruginosa were performed on plate count agar and cetrimide agar, respectively. Plates were incubated at 37 °C for 48 hours.

Results

None of the samples were free from bacterial contamination. P. aeruginosa was detected in 22.6% and 18.3% of samples taken on the first and last working days, respectively.

Conclusions

Suction hoses were heavily contaminated with bacteria, especially opportunistic pathogens, and current disinfection does not adequately control the contamination.

Comparison of Bacterial Load Parameters in Subgingival Plaque during Peri-implantitis and Periodontitis Using the RT-PCR Method

Objective

To estimate the actual parameters of bacterial load in subgingival plaque during periodontitis and peri-implantitis pathologies using the RT-PCR (real-time polymerase chain reaction) method and evaluate their associations with clinical periodontal indicators.

Materials and Methods

Five different groups of subjects were selected according to a formulated design of the study: with mild/moderate periodontitis, with severe periodontitis, with peri-implantitis, healthy periodontal group and healthy peri-implant group. Subgingival plaque samples were formed with paper points inserted in the pocket/sulcus area for 30 seconds. A standardized test the “ParodontoScreen” was provided for identification of target opportunistic pathogens (A. actinomycetemcomitans, P. gingivalis, T. forsythia, P. intermedia, T. denticola) by the RT-PCR.

Results

Bacterial load parameters demonstrated a significant tendency towards an increase within periodontitis progression and during the presence of peri-implantitis pathology. Each targeted mean bacterial load level was statistically associated with periodontitis or peri-implantitis pathology (p < 0, 05) according to the provided univariate analyses and upon condition that bacterial load parameters of healthy sites were used as reference for equiparation. The highest correlation values were found between periodontal probing depth and bacterial load parameters of A. actinomycetemcomitans (r=0, 37; p < 0, 05) and P. gingivalis (r=0, 28; p < 0, 05); and also between clinical attachment loss and bacterial load values of A. actinomycetemcomitans (r=0, 38; p < 0, 05) and P. gingivalis (r=0, 24; p < 0, 05).

Conclusions

Periodontitis and peri-implantitis are associated with the same microbial pathogens even though the distribution pattern of their bacterial load and detection frequency parameters registered with RT-PCR could be distinct and linked to the individual patient-related conditions and the severity stage of pathology.

The bactericidal effect of an atmospheric-pressure plasma jet on Porphyromonas gingivalis biofilms on sandblasted and acid-etched titanium discs

Purpose

Direct application of atmospheric-pressure plasma jets (APPJs) has been established as an effective method of microbial decontamination. This study aimed to investigate the bactericidal effect of direct application of an APPJ using helium gas (He-APPJ) on Porphyromonas gingivalis biofilms on sandblasted and acid-etched (SLA) titanium discs.

Methods

On the SLA discs covered by P. gingivalis biofilms, an APPJ with helium (He) as a discharge gas was applied at 3 different time intervals (0, 3, and 5 minutes). To evaluate the effect of the plasma itself, the He gas-only group was used as the control group. The bactericidal effect of the He-APPJ was determined by the number of colony-forming units. Bacterial viability was observed by confocal laser scanning microscopy (CLSM), and bacterial morphology was examined by scanning electron microscopy (SEM).

Results

As the plasma treatment time increased, the amount of P. gingivalis decreased, and the difference was statistically significant. In the SEM images, compared to the control group, the bacterial biofilm structure on SLA discs treated by the He-APPJ for more than 3 minutes was destroyed. In addition, the CLSM images showed consistent results. Even in sites distant from the area of direct He-APPJ exposure, decontamination effects were observed in both SEM and CLSM images.

Conclusions

He-APPJ application was effective in removing P. gingivalis biofilm on SLA titanium discs in an in vitro experiment.

Prevalence of Asthma in School Children on the Arizona-Sonora Border

BACKGROUND

Mexican-born children living in the United States have a lower prevalence of asthma than other US children. Although children of Mexican descent near the Arizona (AZ)-Sonora border are genetically similar, differences in environmental exposures might result in differences in asthma prevalence across this region.

OBJECTIVE

The objective of this study was to determine if the prevalence of asthma and wheeze in these children varies across the AZ-Sonora border.

METHODS

The International Study of Asthma and Allergy in Children written and video questionnaires were administered to 1753 adolescents from 5 middle schools: Tucson (school A), Nogales, AZ (schools B, C), and Nogales, Sonora, Mexico (schools D, E). The prevalence of asthma and symptoms was compared, with analyses in the AZ schools limited to self-identified Mexican American students.

RESULTS

Compared with the Sonoran reference school E, the adjusted odds ratio (OR) for asthma was significantly higher in US schools A (OR 4.89, 95% confidence interval [CI] 2.72-8.80), B (OR 3.47, 95% CI 1.88-6.42), and C (OR 4.12, 95% CI 1.78-9.60). The adjusted OR for wheeze in the past year was significantly higher in schools A (OR 2.19, 95% CI 1.20-4.01) and B (OR 2.67, 95% CI 1.42-5.01) on the written questionnaire and significantly higher in A (OR 2.13, 95% CI 1.22-3.75), B (OR 1.95, 95% CI 1.07-3.53), and Sonoran school D (OR 2.34, 95% CI 1.28-4.30) on the video questionnaire compared with school E.

CONCLUSIONS

Asthma and wheeze prevalence differed significantly between schools and was higher in the United States. Environmental factors that may account for these differences could provide insight into mechanisms of protection from asthma.