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In vitro comparison of antifungal activity of conventional alcohol sprays and antimicrobial photodynamic therapy on acrylic denture resin

BACKGROUND

Traditionally, alcohol sprays are used for disinfection of acrylic-base denture surfaces. A limited number of studies have assessed the role of antimicrobial photodynamic therapy (aPDT) in this regard; however, it remains debatable whether conventional alcohol sprays are superior to aPDT in terms of antifungal activity or vis versa.

OBJECTIVE

The aim of the present in vitro study is to compare the antifungal activity of conventional alcohol sprays and aPDT on acrylic denture resin.

METHODS

Individuals wearing complete dentures at least on one arch were included. Dentures were randomly divided into three groups. Groups 1-3 were disinfected with an alcohol-based antiseptic spray and aPDT, respectively. Assessment of oral yeast growth was done using swab samples. The culture mediums were incubated at 37∘C for 72 hours and viewed through a microscope. The numbers of colony forming units (CFU/ml) were determined. P< 0.05 were considered statistically significant.

RESULTS

At baseline, the mean CFU/ml in Groups 1-3 were comparable. After disinfection, a statistically significant reduction in microbial CFU/ml was observed in Groups 1 (P< 0.05) and 2 (P< 0.05) compared with baseline. In Group 3, there was no difference in CFU/ml throughout the study. After disinfection, there was no difference in microbial CFU/ml in dentures in Groups 1 and 2.

CONCLUSION

Conventional alcohol sprays are as effective as aPDT towards reducing oral yeasts CFU/ml on acrylic denture resin.

Evaluation of Knowledge, Attitude and Practice of Cross Infection Control Among Students of Dentistry, Dental Hygiene, and Dental Technology in Jordan

Background:

Cross infection control, to reduce the incidence of disease transmission between patients and dental team personnel, is an integral part of good clinical practice.

Objective:

To assess knowledge, attitude and practice of cross infection control among dental, dental hygiene, and dental technology students.

Methods:

Data were collected by a self-administrated questionnaire assessing knowledge, attitude, and practice of infection control measures. The questionnaire was published electronically to final year dental, dental hygiene, and dental technology students through student’s official social media groups .

Results:

Statistically significant difference was found in relation to students' specialization (p-value ≤ 0.05). None of the dental hygienist students had a negative attitude about infection control, while most of participants with a negative attitude were dental technology students (84.6%). No statistically significant difference (p>0.05) was found between groups in regard to cross-infection knowledge, where the level of knowledge ranged from moderate to good.

Conclusion:

Good knowledge, attitude, and practice were reported for dental and dental hygiene students, while good knowledge with a negative attitude was found amongst dental technology students. Specialty affected the practice of infection control measures, yet gender was not a significant variable. Improvement of the university curriculum, particularly for dental technology students, to increase awareness and knowledge of cross infection control is highly recommended.

Infection control awareness level among dental laboratory technicians, Riyadh, Saudi Arabia

Aims and objectives:

Infection control is an essential part in dental practices. Potential disease transmission in the dental lab is well documented. Dental technicians should strictly adhere to the standard precautions in order to prevent potential risks of cross-contamination, thereby producing a safe environment for patients and staff. The aim of this study was to evaluate the knowledge, attitude, and practice among dental lab technicians toward infection control protocols at the dental laboratories of Riyadh.

Materials and methods:

A self-administered questionnaire will be distributed to dental lab technicians working at both private and governmental laboratories in Riyadh, Saudi Arabia. Data were collected from one hundred and twenty-one dental laboratory technicians.

Results:

According to the findings, only 42.9% had an infection control manual display in the dental lab, 43.8% had received infection control training courses as part of their orientation, 40.4% of the technicians had a valid hepatitis B vaccination. Dental technicians are exposed to high risk of injuries, 72.7% of respondents answered Yes, when they were asked about reporting sharp injuries to laboratory administration.

Conclusion:

There was poor compliance to infection control procedures, dental techniques are at increased risk of cross-contamination and infection, they have limited orientation and knowledge on the infection control guideline and policy.

A systematic review of droplet and aerosol generation in dentistry

OBJECTIVES

This review aimed to identify which dental procedures generate droplets and aerosols with subsequent contamination, and for these, characterise their pattern, spread and settle.

DATA RESOURCES

Medline(OVID), Embase(OVID), Cochrane Central Register of Controlled Trials, Scopus, Web of Science and LILACS databases were searched for eligible studies from each database's inception to May 2020 (search updated 11/08/20). Studies investigating clinical dental activities that generate aerosol using duplicate independent screening. Data extraction by one reviewer and verified by another. Risk of bias assessed through contamination measurement tool sensitivity assessment.

STUDY SELECTION

A total eighty-three studies met the inclusion criteria and covered: ultrasonic scaling (USS, n = 44), highspeed air-rotor (HSAR, n = 31); oral surgery (n = 11), slow-speed handpiece (n = 4); air-water (triple) syringe (n = 4), air-polishing (n = 4), prophylaxis (n = 2) and hand-scaling (n = 2). Although no studies investigated respiratory viruses, those on bacteria, blood-splatter and aerosol showed activities using powered devices produced greatest contamination. Contamination was found for all activities, and at the furthest points studied. The operator's torso, operator's arm and patient's body were especially affected. Heterogeneity precluded inter-study comparisons but intra-study comparisons allowed construction of a proposed hierarchy of procedure contamination risk: higher (USS, HSAR, air-water syringe, air polishing, extractions using motorised handpieces); moderate (slow-speed handpieces, prophylaxis, extractions) and lower (air-water syringe [water only] and hand scaling).

CONCLUSION

Gaps in evidence, low sensitivity of measures and variable quality limit conclusions around contamination for procedures. A hierarchy of contamination from procedures is proposed for challenge/verification by future research which should consider standardised methodologies to facilitate research synthesis.

CLINICAL SIGNIFICANCE

This manuscript addresses uncertainty around aerosol generating procedures (AGPs) in dentistry. Findings indicate a continuum of procedure-related aerosol generation rather than the common binary AGP or non-AGP perspective. The findings inform discussion around AGPs and direct future research to support knowledge and decision making around COVID-19 and dental procedures.

Quantitative Analysis of Selected Microorganisms Present at Various Sites in a Prosthetics Clinic and Dental Laboratory during Complete Denture Fabrication

Background: Contamination with oral commensals and pathogenic microorganisms, and cross contamination between clinic and laboratory can occur. The amount of contamination has not been determined. Methods: Samples from different clinical and laboratory stages before and after disinfection (17 sites, 10 samples per stage) were collected. Laboratory surfaces and equipment were swabbed for 10 days (11 sites). Swabs were cultured for total mixed flora, Streptococci, Lactobacilli, Staphylococcus aureus, aerobic Gram-negative bacteria (AGNB) and Candida. Knowledge of infection control among staff and students was assessed. Results: Clinic: In total, 30-40% of the samples overall were contaminated with mixed flora and Streptococci of >100 cfu/swab; >100 cfu of AGNB and Candida were present on 6% and 1% of samples; 2% contained <100 cfu of S. aureus. Laboratory: In total, 17-48% of the samples overall were contaminated with mixed flora and Streptococci of >100 cfu/swab; >100 cfu of AGNB were present on 11% of samples; none contained >100 cfu of Candida. Disinfection significantly reduced the level of all organisms. Knowledge of infection control was sufficient, but compliance was poor. Conclusion: Although the count of mixed flora was high, potential pathogens such as S. aureus and Candida were low. In immunocompromised patients, this can become a problem.

Quality of cross-infection control in dental laboratories. A critical systematic review

Purpose

To identify reported practices for cross-infection control in dental laboratories and to quantify the importance of the flaws encountered.

Data sources

Systematic search (cross-infection AND dental laboratory) at EMBASE, PubMed, SciELO and Scopus databases.

Study selection

Papers reporting on cross-sectional studies providing original data about cross-infection knowledge, practices and attitudes of dental technicians. Papers reporting on a single laboratory or institution were excluded.

Data extraction

Data extraction was undertaken independently by three reviewers using a purpose made form. The outcome of this study was analyzed in five aspects, namely process organization, disinfection, working environment, use of individual protective equipment and vaccination policy.

Results of data synthesis

The systematic search output was 1651 references and 11 papers were finally selected. Flaws were more frequently identified in terms of vaccination policy, biological safety of the working environment and use of individual protective equipment (100%). Slightly better results were found in terms of organization of the cross-infection control process (89.47%) and disinfection practices (85.71%). The application of the formula for disclosing the relative importance of the flaws identified in the literature prioritizes the need for interventions aimed at improving the organization of the cross-infection control procedures, followed by training in item disinfection. The control of the working environment together with the use of individual protective equipments rank closely in importance, followed by the existence of a vaccination policy.

Conclusions

Sub-standard cross-contamination practices seem to be a common finding in dental laboratories, which may well compromise the quality of certain dental treatments.

Effect of Chemical Disinfection on Chitosan Coated PMMA and PETG Surfaces-An In Vitro Study

In oral sciences, chitosan application is of interest due to its antimicrobial and hemostatic activity. Chitosan coating of dentures and other intraoral devices could be beneficial for treatment of denture stomatitis or in the management of postoperative bleeding. Disinfection of dentures and prosthodontic materials is crucial before their use in patients. This study investigated the influence of chemical disinfectants on chitosan-coated surfaces. A total of 100 specimens were made: 50 of PMMA (polymethyl methacrylate), and 50 of PETG (polyethylene terephthalate glycol-modified) material and coated with 2% chitosan acetate solution. In each material, 5 groups (10 specimens each) were established and disinfected with Printosept-ID (L1), MD 520 (L2), Silosept (L3), or Dentavon (L4), or stored in distilled water (L0, control group). After disinfection, all specimens underwent abrasion tests (30,000 cycles in a tooth-brushing simulator). Areas without chitosan coating were measured by digital planimetry both before and after the disinfection/abrasion procedure and a damage-score was calculated. Regarding chitosan coating, the statistical analysis showed a significant influence of the disinfectants tested and significant differences between disinfectants (p < 0.05). Chitosan coating was most stable on PMMA and PETG after disinfection with MD 520 (L2). Otherwise, active oxygen containing disinfectants (L3, L4) led to the greatest alterations in the chitosan coating.

Isolation and Identification of Nonoral Pathogenic Bacteria in the Oral Cavity of Patients with Removable Dentures

Aims and Objectives:

Dentures in the oral cavity may act as a reservoir of microorganisms, which may be related to systemic infections. The aim of this study was to investigate the nonoral pathogenic bacteria in the oral cavity of patients with removable dentures in Shiraz, Southern Iran.

Materials and Methods:

The bacterial flora of saliva samples from 50 men and 50 women with removable dentures and 100 age- and sex-matched controls with normal dentate were compared using culture, Gram staining, and API20E Kit methods. All data were analyzed using SPSS software.

Results:

Except for Enterobacter cloacae isolate (P = 0.03), there was no significant difference between both groups for the presence of Escherichia coli, Klebsiella pneumoniae, nonfermenting Gram-negative bacilli, Raoultella ornithinolytica, Raoultella planticola, Kluyvera spp., and Enterobacter aerogenes. No significant correlation was noticed between age and presence of bacteria in the oral cavity. The Gram-negative rod bacteria were more in males, but the difference was not significant. When a total of Gram-negative rods were considered, there was a significant difference between case and control groups (P = 0.004).

Conclusions:

Based on our findings that nonoral pathogenic bacteria are detected from the saliva of the denture wearers, general and oral health measures in patients with removable dentures should be adopted to decrease the risk of cross infection.

Evaluation of Surface Microhardness Following Chemical and Microwave Disinfection of Commercially Available Acrylic Resin Denture Teeth

INTRODUCTION

Denture disinfection is an indispensable procedure for preventing cross contamination and the maintenance of a healthy oral mucosa in patients rehabilitated with removable dental prosthesis. Nevertheless, they are known to cause changes in the physical and mechanical properties of denture base resins and acrylic resin denture teeth following immersion of a denture in a suitable chemical disinfectant solution or by undergoing microwave irradiation. One such mechanical property indicator for artificial tooth materials is hardness.

AIM

To assess the surface hardness of acrylic resin teeth of three different commercial brands (Ivoclar, Newace, Acryrock) following chemical (2% glutaraldehyde, 1% sodium hypochlorite) and microwave disinfections.

MATERIALS AND METHODS

Ten specimens of each of the three commercial brands were made for control and each simulated disinfection type and stored in distilled water at room temperature for 24 hours. After water storage, specimens were immersed in 2% glutaraldehyde and 1% sodium hypochlorite (one and three cycles) at room temperature for 10 minutes. Irradiation with microwave (one and three cycles) was done in domestic microwave for three minutes with the specimens immersed in 150 ml of distilled water. The specimens were stored in distilled water at room temperature for seven days after each disinfection cycle. Vickers hardness measurements were made using a hardness indenter under a load of 50 g force for 10 seconds. Data was subjected to repeated measure two-way ANOVA test and Tukey's test.

RESULTS

There were statistically significant differences for the variables disinfection, tooth, and cycle (p<0.05 for teeth & disinfectant interaction, p<0.05 cycle and disinfectant interaction). The mean surface hardness following one microwave disinfection cycle was lower than control, glutaraldehyde and sodium hypochlorite. Comparison among cycles revealed that microhardness was significantly decreased for three cycles of microwave disinfection.

CONCLUSION

It was concluded that there was no significant difference in microhardness when the teeth were subjected to chemical disinfection but three cycles of microwave disinfection produced decrease in the microhardness of different types of artificial teeth.

Uniform-related infection control practices of dental students

BACKGROUND

Uniform-related infection control practices are sometimes overlooked and underemphasized. In Saudi Arabia, personal protective equipment must meet global standards for infection control, but the country's Islamic legislature also needs to be taken into account.

AIM

To assess uniform-related infection control practices of a group of dental students in a dental school in Saudi Arabia and compare the results with existing literature related to cross-contamination through uniforms in the dental field.

METHOD

A questionnaire was formulated and distributed to dental students at King Abdulaziz University Faculty of Dentistry in Jeddah, Saudi Arabia, which queried the students about their uniform-related infection control practices and their methods and frequency of laundering and sanitizing their uniforms, footwear, and name tags.

RESULTS

There is a significant difference between genders with regard to daily uniform habits. The frequency of uniform washing was below the standard and almost 30% of students were not aware of how their uniforms are washed. Added to this, there is no consensus on a unified uniform for male and female students.

CONCLUSION

Information on preventing cross-contamination through wearing uniforms must be supplied, reinforced, and emphasized while taking into consideration the cultural needs of the Saudi society.

Microbial contamination of laboratory constructed removable orthodontic appliances

OBJECTIVES

This study aims to determine whether laboratory constructed removable orthodontic appliances are free from microbial contamination prior to clinical use and to evaluate the dental hospital cross-infection procedures to ensure that patient-derived contamination does not enter the construction process, thereby propagating a cycle of cross-contamination.

MATERIALS AND METHODS

The construction process of removable orthodontic appliances from three individuals was evaluated at every stage, from impression to final delivery of the appliance using molecular microbiological techniques. The bacterial profiles at each stage of appliance construction were obtained using denaturing gradient gel electrophoresis, along with the bacterial profiles of the three participants' saliva. This enabled the bacterial profiles found at each stage of construction to be compared directly with the saliva of the person for whom the appliance was being constructed. Bacteria were identified at each stage using 16S rDNA PCR amplification and sequence phylogeny.

RESULTS

There was no evidence of bacterial cross-contamination from patients to the laboratory. The current process of disinfection of impression appears to be adequate. Contamination was found on the final removable appliances (0.97 × 10(2)-1.52 × 10(3) cfu ml(-1)), and this contamination occurred from within the laboratory itself.

CONCLUSIONS

Every effort is made to reduce potential cross-infection to patients and dental professionals. Newly constructed removable appliances were shown not to be free from contamination with bacteria prior to clinical use, but this contamination is environmental. Further studies would be required to determine the level of risk this poses to patients.

CLINICAL SIGNIFICANCE

Dental professionals have a duty of care to minimise or eradicate potential risks of cross-infection to patients and other members of the team. To date, much less attention has been paid to contamination from the orthodontic laboratory, so contamination and infection risks are unknown.

Workplace determinants of endotoxin exposure in dental healthcare facilities in South Africa

OBJECTIVES

Aerosols generated during dental procedures have been reported to contain endotoxin as a result of bacterial contamination of dental unit water lines. This study investigated the determinants of airborne endotoxin exposure in dental healthcare settings.

METHODS

The study population included dental personnel (n = 454) from five academic dental institutions in South Africa. Personal air samples (n = 413) in various dental jobs and water samples (n = 403) from dental handpieces and basin taps were collected. The chromogenic-1000 limulus amebocyte lysate assay was used to determine endotoxin levels. Exposure metrics were developed on the basis of individually measured exposures and average levels within each job category. Analysis of variance and multivariate linear regression models were constructed to ascertain the determinants of exposure in the dental group.

RESULTS

There was a 2-fold variation in personal airborne endotoxin from the least exposed (administration) to the most exposed (laboratory) jobs (geometric mean levels: 2.38 versus 5.63 EU m(-3)). Three percent of personal samples were above DECOS recommended exposure limit (50 EU m(-3)). In the univariate linear models, the age of the dental units explained the most variability observed in the personal air samples (R(2) = 0.20, P < 0.001), followed by the season of the year (R(2) = 0.11, P < 0.001). Other variables such as institution and total number of dental units per institution also explained a modest degree of variability. A multivariate model explaining the greatest variability (adjusted R(2) = 0.40, P < 0.001) included: the age of institution buildings, total number of dental units per institution, ambient temperature, ambient air velocity, endotoxin levels in water, job category (staff versus students), dental unit model type and age of dental unit.

CONCLUSIONS

Apart from job type, dental unit characteristics are important predictors of airborne endotoxin levels in this setting.