Mitigating saliva aerosol contamination in a dental school clinic.

BACKGROUND: Transmission of COVID-19 via salivary aerosol particles generated when using handpieces or ultrasonic scalers is a major concern during the COVID-19 pandemic. The aim of this study was to assess the spread of dental aerosols on patients and dental providers during aerosol-generating dental procedures. METHODS: This pilot study was conducted with one volunteer. A dental unit used at the dental school for general dental care was the site of the experiment. Before the study, three measurement meters (DustTrak 8534, PTrak 8525 and AeroTrak 9306) were used to measure the ambient distribution of particles in the ambient air surrounding the dental chair. The volunteer wore a bouffant, goggles, and shoe covers and was seated in the dental chair in supine position, and covered with a surgical drape. The dentist and dental assistant donned bouffant, goggles, face shields, N95 masks, surgical gowns and shoe covers. The simulation was conducted by using a high-speed handpiece with a diamond bur operating in the oral cavity for 6 min without touching the teeth. A new set of measurement was obtained while using an ultrasonic scaler to clean all teeth of the volunteer. For both aerosol generating procedures, the aerosol particles were measured with the use of saliva ejector (SE) and high-speed suction (HSS) followed a separate set of measurement with the additional use of an extra oral high-volume suction (HVS) unit that was placed close to the mouth to capture the aerosol in addition to SE and HSS. The distribution of the air particles, including the size and concentration of aerosols, was measured around the patient, dentist, dental assistant, 3 feet above the patient, and the floor. RESULTS: Four locations were identified with elevated aerosol levels compared to the baseline, including the chest of the dentist, the chest of patient, the chest of assistant and 3 feet above the patient. The use of additional extra oral high volume suction reduced aerosol to or below the baseline level. CONCLUSIONS: The increase of the level of aerosol with size less than 10 µm was minimal during dental procedures when using SE and HSS. Use of HVS further reduced aerosol levels below the ambient levels.

Fluoride supplements, dental caries and fluorosis: a systematic review.

BACKGROUND: In this review, the authors examine evidence regarding the effectiveness of fluoride supplements in preventing caries and their association with dental fluorosis. METHODS: Using tested search filters, the authors searched MEDLINE, the Cochrane Central Register of Controlled Trials, OVID Evidence-based Reviews and EMBASE. The authors agreed on the inclusion of 20 reports from 12 trials that met defined criteria. They also included five studies published since 1997 regarding the association between dental fluorosis and supplements. RESULTS: Eleven of the reports evaluated dosage schedules similar to that recommended by the American Dental Association. One potentially highly biased study of primary teeth of children during the first three years of life reported a 47.2 percent reduction in dental caries experience. Investigators in one trial involving 3- to 6-year-old children found a 43.0 percent difference, and another trial of children in this age group did not find a significant benefit. Researchers in several studies involving older children detected a significant reduction in caries increments in permanent teeth with the use of fluoride supplements. Fifteen of the studies had withdrawal rates of 30 percent or higher. All of the five included studies that evaluated the association between use of fluoride supplements and dental fluorosis found that use of the supplements increased the risk of mild-to-moderate fluorosis. CONCLUSIONS: There is weak and inconsistent evidence that the use of fluoride supplements prevents dental caries in primary teeth. There is evidence that such supplements prevent caries in permanent teeth. Mild-to-moderate dental fluorosis is a significant side effect. CLINICAL IMPLICATIONS: The current recommendations for use of fluoride supplements during the first six years of life should be re-examined.

Radiographic detection of approximal caries: a comparison between senior dental students and senior dental hygiene students.

PURPOSE: Dental hygienists do not legally (or definitively) diagnose caries, but they often are responsible for preliminary interpretation of bitewing (BW) radiographs taken during prophylaxis appointments. Given this custom of practice, it is important to understand whether there is a difference between the capabilities of dental hygienists and dentists in interpreting BWs based on education and clinical experience. This study compared proximal carious lesion classification from BWs by senior dental students and senior dental hygiene students. METHODS AND MATERIALS: Volunteers (40 dental [D] and 54 dental hygiene [DH] students) classified proximal carious lesions from BWs of 96 extracted teeth, which were mounted in wax to simulate quadrants of the mouth. A soft tissue equivalent was placed in front of the mounted teeth before x-ray exposure. Films were developed automatically and mounted into six sets point scale. The teeth were sectioned vertically and evaluated clinically at 5x magnification with an explorer. The "gold standard" of carious lesion classification was then compared to the students' classifications. RESULTS: All students detected 54% of the carious lesions and correctly identified lack of caries 80.5% of the time. There were no differences between the two groups of students in terms of sensitivity, but dental students showed higher specificity (p = 0.0006). CONCLUSION: Permitting dental hygienists to make preliminary interpretations of caries from BWs in the dental office appears to be an acceptable practice.