The Prevalence and Severity of Dental Caries Among Pregnant Women in the State of Rio de Janeiro, Brazil.

AIM: To assess in a pilot study the prevalence and severity of dental caries among pregnant women compared to non-pregnant women in the state of Rio de Janeiro, Brazil. MATERIALS AND METHODS: A cross-sectional, observational study was conducted. Data collection consisted of clinical examinations and general questionnaires concerning oral hygiene habits and recent dental visits of pregnant and non-pregnant women. Prevalence and severity of caries was determined by the CAST index and the CAST severity score. Permission for this study was granted by the National Research Ethics Commission of Brazil. Written informed consent was obtained from all participants. RESULTS: In total, 67 pregnant women were included (mean age (SD) 25.5 ± 5.4 years) and 79 non-pregnant women (26.0 ± 5.3 years). Mean number of teeth with untreated caries (CAST 4-7) among pregnant women was significantly lower (1.2 ± 1.8) compared to non-pregnant women (2.7 ± 4.0; Mann-Whitney test, p = 0.027). In both groups, 40-60% were in need of curative treatment. There was no significant difference between the two groups in frequency of dental visits (p > 0.05), but pregnant women brushed their teeth more often (Mann-Whitney test, p < 0.001). CONCLUSION: Pregnant women in the state of Rio de Janeiro have fewer untreated caries and less severe dental caries compared to non-pregnant women. Still, half of all women in this study are in need of curative treatment for at least one tooth. Effective preventive programs should therefore be developed to stimulate preventive oral care among all women.

[Oral hygiene in patients with motor neuron disease: a cross-sectional survey]. / Mondzorg bij patiënten met neuromusculaire aandoeningen: een cross-sectioneel vragenlijstonderzoek.

Neuromuscular disorders cause damage to the motor nerves. Arm-hand function can severely be impaired. The needs of and limitations of patients with neuromuscular disorders and the role of their carers in providing oral hygiene were studied. To this end, an online survey was sent to 706 patients with a neuromuscular disorder (amyotrophic lateral sclerosis, spinal muscular atrophy, primary lateral sclerosis and progressive bulbar palsy). The survey questions concerned, among other things, self-reliance, the oral situation and oral hygiene. Oral health-related quality of life and subjective well-being were also measured. A total of 259 patients (36.7%) responded, of whom 71.9% declared themselves not to have been informed about the importance of maintaining good oral health. Moreover, 40.4% wished to receive help from an oral care professional regarding their oral hygiene; 19.8% was not satisfied with the oral care they provided for themselves or as provided by their carers. It was concluded that attention to oral hygiene for patients with neuromuscular disorders by both multidisciplinary treatment teams and oral care professionals is required.

[Cross contamination: spatters, aerosols, and biofilm in dental practices]. / Kruiscontaminatie: spatten, aerosolen en biofilm in de mondzorgpraktijk.

During treatment in dental practices, drops of different sizes are produced (spats and aerosols). Microorganisms in these drops are of human origin or originate from the water in the dental unit. Therefore, these drops can contribute to cross contamination in dental practices. Large drops settle quickly, while smaller drops can remain suspended in the air for a longer period of time. The highest level of contamination is found in the immediate vicinity of the source (the patient's mouth). Further away from the source and after stopping drop producing activities, the level of contamination in the air is comparable to control circumstances. Studies into the spread of viruses via this route in the dental practice have not yet been conducted. The risk of catching an infectious disease in the dental practice seems limited, but can be high in the case of a virulent microorganism, when the circumstances for spread of the virus are favorable, or if the recipient is immunocompromised.

Low prevalence of multi-resistant bacteria in undergraduate dental students; an observational case-control multi-centre study in Europe.

Objective: This study assessed the prevalence of MRSA, ESBL and VRE in students from four dental schools in Europe. Methods: The hand, tongue and nostrils of the students who treated patients (study group) and who did not treat patients (control group) were sampled. After incubation in TSB and subculturing in the presence of 4 µg/ml oxacillin, positive cultures were identified for Staphylococcus aureus by Mannitol salt agar and agglutination tests. The presence of MRSA was confirmed by specific PCR on the species and on the SSCmec genes. ESBL and VRE were isolated using specific CHROMagar and confirmed using antibiotic sensitivity tests. Results: Of the 879 students who participated in this study (454 students which treated patients, 425 controls) a total of 50 students (5.7%) tested positive for a multi-drug resistant bacterium (MDRB); 13 (1.5%) students tested positive for MRSA, 26 (3.0%) for ESBL and 12 (1.4%) for VRE. No statistically significant differences were found between the students who treated patients compared to the control group for any of the MDRB and study centres, excluding MRSA carriage in the Italian student population. The use of antibiotics the year before sampling, was positively associated with the presence of an MDRB (OR 2.0; 95% Confidence Interval 1.10-3.68; p = 0.02). Conclusion: The risk for MDRB carriage and sequential transmission of MDRB for dental health care students and their patients were acceptably low.

Infection control in dental health care during and after the SARS-CoV-2 outbreak.

COVID-19 is an emerging infectious disease caused by the widespread transmission of the coronavirus SARS-CoV-2. Some of those infected become seriously ill. Others do not show any symptoms, but can still contribute to transmission of the virus. SARS-CoV-2 is excreted in the oral cavity and can be spread via aerosols. Aerosol generating procedures in dental health care can increase the risk of transmission of the virus. Due to the risk of infection of both dental healthcare workers and patients, additional infection control measures for all patients are strongly recommended when providing dental health care. Consideration should be given to which infection control measures are necessary when providing care in both the current situation and in the future.

[Infection prevention in dental care during the outbreak of SARS-CoV-2]. / Infectiepreventie in de mondzorg tijdens de uitbraak van SARS-CoV-2.

COVID-19 is an emerging infectious disease with widespread transmission of the coronavirus SARS-CoV-2 in the Netherlands. Some of those infected become seriously ill. Others do not show any symptoms, but can still contribute to the transmission of the virus. SARS-CoV-2 is excreted in the oral cavity and can be spread via aerosols. Therefore, there is an increased risk of its spread during aerosol-producing treatments in dental care clinics. Due to the risk of infection of dental care workers and patients, and based on the evidence currently available, additional infection control measures for all patients are strongly recommended when providing emergency dental care in this phase of the pandemic. Other treatments should be postponed. Based on guidance in scientific literature and advice from the Dutch National Institute for Public Health and the Environment (RIVM), consideration should be given to what infection control measures are necessary when providing emergency and regular dental care in both the current situation and in the future.

Modeling of the Transmission of Coronaviruses, Measles Virus, Influenza Virus, Mycobacterium tuberculosis, and Legionella pneumophila in Dental Clinics.

Dental health care workers are in close contact to their patients and are therefore at higher risk for contracting airborne infectious diseases. The transmission rates of airborne pathogens from patient to dental health care workers are unknown. With the outbreaks of infectious diseases, such as seasonal influenza, occasional outbreaks of measles and tuberculosis, and the current pandemic of the coronavirus disease COVID-19, it is important to estimate the risks for dental health care workers. Therefore, the transmission probability of these airborne infectious diseases was estimated via mathematical modeling. The transmission probability was modeled for Mycobacterium tuberculosis, Legionella pneumophila, measles virus, influenza virus, and coronaviruses per a modified version of the Wells-Riley equation. This equation incorporated the indoor air quality by using carbon dioxide as a proxy and added the respiratory protection rate from medical face masks and N95 respirators. Scenario-specific analyses, uncertainty analyses, and sensitivity analyses were run to produce probability rates. A high transmission probability was characterized by high patient infectiousness, the absence of respiratory protection, and poor indoor air quality. The highest transmission probabilities were estimated for measles virus (100%), coronaviruses (99.4%), influenza virus (89.4%), and M. tuberculosis (84.0%). The low-risk scenario leads to transmission probabilities of 4.5% for measles virus and 0% for the other pathogens. From the sensitivity analysis, it shows that the transmission probability is strongly driven by indoor air quality, followed by patient infectiousness, and the least by respiratory protection from medical face mask use. Airborne infection transmission of pathogens such as measles virus and coronaviruses is likely to occur in the dental practice. The risk magnitude, however, is highly dependent on specific conditions in each dental clinic. Improved indoor air quality by ventilation, which reduces carbon dioxide, is the most important factor that will either strongly increase or decrease the probability of the transmission of a pathogen.

Dental aerosols: microbial composition and spatial distribution.

Background: High-speed dental instruments produce aerosols, which can contribute to the transmission of pathogenic microorganisms. The aim of this study is to describe the microbial load and - composition and spatial distribution of aerosols in dental clinics. Methods: In four dental clinics active and passive sampling methods were used before, during and after treatment and at different locations. Retrieved colony forming units (CFU) were sequenced for taxon identification. Results: The samples contained up to 655 CFU/plate/30 minutes and 418 CFU/m3/30 minutes during dental treatment for active and passive sampling, respectively. The level of contamination after treatment and at 1.5 m distance from the patient's head was similar to the start of the day. The highest contamination was found at the patient's chest area. The aerosols consisted of 52 different taxa from human origin and 36 from water. Conclusion: Contamination in dental clinics due to aerosols is mainly low, although high level of contamination with taxa from both human and water origin was found within 80 cm around the head of the patient. Our results stress the importance of infection control measures on surfaces in close proximity to the head of the patient as well as in dental water lines.

Heterogeneity in the efficacy of dental chemical disinfectants on water-derived biofilms in vitro.

Conditions in dental unit waterlines are favourable for biofilm growth and contamination of dental unit water. The aim of this study was to assess the effect of several chemical disinfectants on bacteria in a biofilm model. Water-derived biofilms were grown in a static biofilm model (Amsterdam Active Attachment model), using two growth media. Biofilms were challenged with Alpron/Bilpron, Anoxyl, Citrisil, Dentosept, Green & Clean, ICX and Oxygenal in shock dose and maintenance doses. The concentration and the composition of the chemical disinfectants influenced the number of culturable bacteria in the biofilms. The application of a single shock dose followed by a low dose of the same chemical disinfectants resulted in the greatest suppression of viable bacteria in the biofilms. Exposure to Citrisil and ICX consistently resulted in failure to control the biofilms, while Alpron/Bilpron had a substantial and relevant effect on the number of bacteria in the biofilms.

Cross-transmission in the Dental Office: Does This Make You Ill?

PURPOSE OF REVIEW: Recently, numerous scientific publications were published which shed new light on the possible risks of infection for dental healthcare workers and their patients. This review aimed to provide the latest insights in the relative risks of transmission of (pathogenic) micro-organisms in the dental office. RECENT FINDINGS: Of all different routes of micro-organism transmission during or immediately after dental treatment (via direct contact/via blood-blood contact/via dental unit water and aerosols), evidence of transmission is available. However, the recent results put the risks in perspective; infections related to the dental office are most likely when infection control measures are not followed meticulously. SUMMARY: The risk for transmission of pathogens in a dental office resulting in an infectious disease is still unknown; it seems to be limited in developed countries but it cannot be considered negligible. Therefore, maintaining high standards of infection preventive measures is of high importance for dental healthcare workers to avoid infectious diseases due to cross-contamination.

[Implementation of effective infection control: furnishing a -dental practice]. / Infectiepreventie in de praktijk ­ het inrichten van de tandartspraktijk.

The increasing resistance to antibiotics and the aging of the population of patients who visit the dental practice can lead to more frequent infections with (resistant) microorganisms. The prevention of cross contamination by the implementation of effective measures in the area of hygiene and procedures of infection control is therefore important. The furnishing of a dental practice can play an important part in prevention. What are the important issues in furnishing a practice? A distinction is made between 'critical' and 'non-critical' rooms. Patients are only treated and instruments are only prepared for reuse in critical rooms. In these rooms, a strict separation is maintained between clean and contaminated, in both place and time. Only furniture that is strictly necessary for the treatment of patients is present in the critical rooms. Materials and equipment that are kept within the splatter area must be stored as much as possible in drawers and closed cabinets. Water taps can be controlled in a touch-free manner and are located within the present walking routes of the practice.

Factors Influencing the Competition between Streptococcus oligofermentans and Streptococcus mutans in Dual-Species Biofilms.

Previous studies have shown that Streptococcus oligofermentans inhibits the growth of cariogenic Streptococcus mutans in biofilms in vitro and is considered a probiotic candidate for caries prevention. This study aimed to examine the effects of various environmental factors on the competition between S. oligofermentans and S. mutans in a dual-species biofilm model. Single or dual S. oligofermentans and S. mutans biofilms were grown in a 96-well active attachment model for 48 h. Several growth conditions were examined in the model, namely: S. oligofermentans was inoculated 24 h before S. mutans or vice versa; the growth medium was supplemented with 0.2% sucrose or 0.4% glucose; biofilms were grown under a constantly neutral pH or pH-cycling condition, which included 8 h of neutral pH and 16 h of pH 5.5. The 48-h biofilms were examined for viable cell counts and lactic acid and hydrogen peroxide production ability. When S. oligofermentans was inoculated first, it clearly inhibited the growth of S. mutans and reduced the biofilm lactic acid production by up to 8-fold through hydrogen peroxide production, independently of sugar supply and pH conditions. When S. mutans was inoculated first, the level of inhibition by S. oligofermentans varied depending on the sugar supply and pH conditions. Thus, the inhibition efficacy of S. oligofermentans against S. mutans in dual-species biofilms is influenced by environmental factors. This study provides practical information on how to maximize the efficacy of S. oligofermentans.

Diffusion of antimicrobials in multispecies biofilms evaluated in a new biofilm model.

AIM: To describe the application of a newly-developed in vitro model in which the diffusion of antimicrobials in oral biofilms can be studied. METHODOLOGY: In a flow chamber consisting of three parallel feeding channels connected with each other by eight perpendicular side channels, multispecies biofilms were grown from saliva of a single donor for 48 h. The dimensions of the side channels were 100 µm × 100 µm × 5130 µm (H × W × L). When one or more side channels were filled with biofilm, the biofilms were stained with fluorescent stains. Then, one side-channel biofilm was selected and treated with phosphate buffered saline, 2% sodium hypochlorite (NaOCl), 17% ethylenediaminetetra-acetic acid (EDTA) or modified salt solution (MSS). Diffusion of the irrigants was observed by acquiring fluorescence images at 10× objective every 15 s for 30 min. RESULTS: It was possible to culture biofilms in the narrow (100 µm) channels. The biofilms varied in phenotype. In this model, no diffusion of NaOCl into the biofilms was seen after its application. Seventeen-percentage EDTA only diffused into the biofilm up to 200 µm in 30 min. MSS did diffuse in the biofilm over a distance of 450 µm within 2 min after a single application. CONCLUSIONS: This new model enables the investigation of the diffusion of antimicrobials in biofilms. Other applications to improve our understanding of the characteristics of biofilms are now possible.

In mixed biofilms Enterococcus faecalis benefits from a calcium hydroxide challenge and culturing.

AIM: To evaluate the fate of Enterococcus faecalis in dual-species and multispecies biofilms after treatment with calcium hydroxide (Ca(OH)2 ). METHODOLOGY: Biofilms were cultured from laboratory strains of E. faecalis and Pseudomonas aeruginosa, or from microbiota retrieved from primary root canal infections. The biofilms were then treated with Ca(OH)2 . The proportion of E. faecalis and P. aeruginosa and their susceptibility to disinfection were evaluated in a viability assay. In the mixed-species assay, the presence and proportions of E. faecalis before and after Ca(OH)2 treatment were evaluated with a quantitative polymerase chain reaction assay. Groups were compared using Mann-Whitney U-test and Student's t-tests. An α <0.05 was considered statistically significant. RESULTS: After Ca(OH)2 treatment in dual-species biofilms, the proportion of E. faecalis had increased (P < 0.001), whereas the total number of CFUs per biofilm was equal. Enterococcus faecalis was equally susceptible to disinfection by sodium hypochlorite (NaOCl) or by chlorhexidine. Pseudomonas aeruginosa had become more susceptible to NaOCl disinfection. The root canal isolates contained no detectable amounts of E. faecalis. After biofilm culturing or Ca(OH)2 treatment, it appeared that E. faecalis must have been present in 5 of 6 (83%) root canal samples. CONCLUSIONS: Calcium hydroxide favours the population of E. faecalis in a dual-species biofilm. Culturing multispecies root canal isolates makes E. faecalis detectable. E. faecalis was often present in primary endodontic infections, albeit in low numbers.

[Endodontics in motion: new concepts, materials and techniques 4. Root canal disinfection in 2015]. / Endodontologie in beweging: nieuwe concepten, materialen en technieken 4. Wortelkanaaldesinfectie anno 2015.

Apical periodontitis is an inflammatory response around the root tip of a tooth to microbial infection of the root canal system. Therefore, disinfection of the root canal system is the most important aim of root canal treatment. There are various mechanical and chemical ways to clean and disinfect. Most methods, however, cannot be relied upon to fully decontaminate in all cases. There are problems, for example, with the proper concentrations of disinfectant agents, like sodium hypochlorite. But the more recent agents, like ethylenediaminetetraacetic acid, calcium hydroxide or antibiotic pastes also have disadvantages, which are mostly a result of poor access of the irrigant to the biofilm bacteria in the affected root canals. Currently, a new strategy with a modified salt solution is under investigation that offers the prospect of being used as a root canal irrigant. At this moment the preferred treatment still seems to be to remove infected tissue as much as possible and to create access for irrigation procedures. The best results are achieved with 1-2% sodium hypochlorite as a disinfectant, possibly alternating with ethylenediaminetetraacetic acid as a cleansing agent. There is no scientific evidence for the successful use of calcium hydroxide.

[Dissertation 25 years after date 42. Dental caries and the role of specific bacteria]. / Proefschriften 25 jaar na dato 42. Tandcariës en de rol van specifieke bacteriën.

During the past 25 years, oral microbiology has developed from researching a limited number of pathogenic microorganisms to a field in which the entire oral micro flora is studied. While 25 years ago, a limited number of species were studied, now the thousands of species that can be found in the mouth are the subject of research. We can now study the effects of bacteria and fungi on each other, but also make small steps in terms of features that microorganisms occupy in the network of the complex biofilm. The biofilm can be seen as a complex ecosystem, which may be unique to each individual and certainly should not always be treated antimicrobially. It is better to stimulate the healthy biofilm and to prevent transmission of pathogens by targeted infection prevention measures. These measures may only be applied if appropriate microbiological knowledge is present.

Restoration materials and secondary caries using an in vitro biofilm model.

This in vitro study investigated whether restoration materials and adhesives influence secondary caries formation in gaps using a short-term in vitro biofilm model. Sixty enamel-dentin blocks were restored with 6 different restoration materials with or without adhesives (n = 10 per group) with a gap: 1) Clearfil AP-X composite, 2) Clearfil AP-X composite + SE Bond, 3) Clearfil AP-X composite + ProtectBond, 4) Filtek Silorane composite, 5) Filtek Silorane composite + Silorane System adhesive, or 6) Tytin amalgam. Specimens were subjected to an intermittent 1% sucrose biofilm model for 20 days to create artificial caries lesions. Lesion progression in the enamel-dentin next to the different materials was measured in lesion depth (LD) and mineral loss (ML) using transversal wavelength independent microradiography (T-WIM). A regression analysis was used to compare the LD and ML of the different restoration materials at 4 measurement locations: 1 location at the surface of the enamel, 1 location at the wall of the enamel, and 2 locations at the wall of the dentin. A statistically significant effect of AP-X composite with Protect Bond was found for LD and ML at the WallDentin1 location, leading to less advanced wall lesions. An additional finding was that gap size was also statistically significant at the 2 wall locations in dentin, leading to increasing lesion progression with wider gaps. In conclusion, adhesives can influence wall lesion development in gaps. Protect Bond showed significantly less caries progression compared to bare restoration materials or other adhesives in this short-term in vitro biofilm model.

Cytotoxicity, interaction with dentine and efficacy on multispecies biofilms of a modified salt solution intended for endodontic disinfection in a new in vitro biofilm model.

AIM: To investigate the cytotoxicity of a modified salt solution (MSS) and evaluate the antimicrobial properties of MSS on in vitro biofilm models. METHODOLOGY: In a metabolic assay, fibroblasts derived from periodontal ligaments (PDL) of human extracted teeth were cultured and challenged with MSS or controls. Then, in active attachment biofilm models, the efficacy of MSS in the presence of dentine powder and in eliminating mature biofilms was investigated. In the dentine assay, a biofilm of Enterococcus faecalis was employed. For the final assay, microorganisms were retrieved from infected root canals and cultured to produce biofilms. After the treatments with MSS or the controls, the biofilms were collected, serially diluted and plated. The colony-forming units were counted. One-way anova was used to analyse the differences between the groups. A P < 0.05 was considered significant. RESULTS: The PDL fibroblasts remained metabolically active after challenges with MSS. Dentine powder did not alter the efficacy of MSS (P > 0.05). In endodontic biofilms, the culturable bacteria were equally reduced by MSS, 2% chlorhexidine (CHX) or 2% sodium hypochlorite (NaOCl) (P > 0.05). CONCLUSIONS: Modified salt solution is noncytotoxic in vitro and has good antimicrobial properties equal to CHX and NaOCl. Although the results are promising, ex vivo and in vivo studies are needed before its use as an interappointment root canal dressing can be considered.