The Effect of Mechanical Tongue Cleaning on Oral Malodor and Tongue Coating

Background: Mechanical tongue cleaning is an important oral hygiene procedure; it is known that a significant cause of volatile sulfur compounds (VSCs), a major component of bad breath, is due to the bacteria coating the tongue. This study was conducted to identify the effect of mechanical tongue cleaning on reducing bad breath and tongue coating. Methods: Various mechanical tongue-cleaning methods were studied, including removing tongue coating using a toothbrush, removing tongue coating using a tongue scraper, and removing tongue coating using a toothbrush and a tongue scraper together. The results were as follows. Results: First, the organic bad breath measurement value after cleaning the tongue significantly decreased in the group using only the toothbrush, the group using only the tongue scraper, and the group using both the toothbrush and the tongue scraper. However, there was no difference between the groups. Second, after cleaning the tongue, the measured values of the tongue coating in the values of WTCI (Winkel’s tongue coating index) and Qray view were significantly reduced in all three groups, and there was no difference between the groups. Third, the gas measurement value in the oral cavity using a machine significantly decreased only the H2S value of the group using the tongue scraper immediately after the mechanical tongue cleaning. Conclusions: From these results, it can be confirmed that mechanical tongue cleaning is effective at reducing bad breath and tongue coating. However, in this study, there was no difference in the reduction effect according to the tools (groups) used for mechanical tongue cleaning. It can therefore be seen that wiping accurately from the rear of the tongue to the front is more effective at reducing bad breath and tongue coating.

Characteristics of oxygen concentration and the role of correction factor in real-time GI breath test

ObjectiveA high quality end-expiratory breath sample is required for a reliable gastrointestinal breath test result. Oxygen (O2) concentration in the breath sample can be used as a quality marker. This study investigated the characteristics of O2 concentration in the breath sample and the impact of using a correction factor in real-time breath measurement.DesignThis study includes two separate groups of patient data. Part 1 of the study analysed the patient’s ability to deliver end-expiratory breath samples over a 2-year period (n=564). Part 2 of the study analysed a separate group of patients (n=47) with additional data to investigate the O2 characteristics and the role of correction factor in breath test.ResultsThe results indicated 95.4% of 564 patients were able to achieve an O2 concentration below 14% in their end-expiratory breath. Part 2 of the study revealed that the distribution of O2 concentration was between 9.5% and 16.2%. Applying a correction factor to predict the end-expiratory H2 and CH4 values led to an average measurement error of −36.4% and −12.8%, respectively.ConclusionThe majority of patients are able to deliver a high quality end-expiratory breath sample, regardless of age or gender. The correction factor algorithm is unreliable when predicting the end-expiratory result at 15% O2 and it would have resulted in false negative result for 50% of the positive cases in this study. It has also indicated that the continuous O2 measurement is essential to ensure breath sample quality by preventing secondary breathing during real-time breath collection.

Ultra-Sensitive Isopropanol Biochemical Gas Sensor (Bio-Sniffer) for Monitoring of Human Volatiles

Our groups have previously developed a biochemical gas sensor to measure isopropanol (IPA) in exhaled air and have applied it for breath IPA investigation in healthy subjects and diabetes patients. In this study, the original bio-sniffer was modified with a series of components that improved the limit of detection (LOD). First, the modified IPA bio-sniffer used a C8855-type photomultiplier tube (PMT) that performed well in the photon sensitivity at the peak wavelength of nicotinamide adenine dinucleotide (NADH) fluorescence. Second, the multi-core bifurcated optical fiber, which incorporated 36 fibers to replace the previous dual-core type, enhanced the fluorescence collection. Third, the optical fiber probe was reinforced for greater width, and the flow-cell was redesigned to increase the area of the enzyme-immobilized membrane in contact with the air sample. These modifications lowered the detection limit to 0.5 ppb, a significant increase over the previous 1.0 ppb. Moreover, the modified bio-sniffer successfully analyzed the IPA concentration in exhaled air from a volunteer, which confirmed its capability for real-world sample detection. The modified bio-sniffer is more applicable to breath measurement and the detection of other extremely-low-concentration samples.

The effectiveness of a contingent financial incentive to improve trial follow up; a randomised study within a trial (SWAT)

Objectives To evaluate the effectiveness of a contingent financial incentive (£10 note in addition to a routinely provided £10 voucher) versus no contingent financial incentive, on improving the retention rate in a randomised controlled trial (RCT). Methods A two arm ‘Study within a Trial’ (SWAT) embedded within a host RCT (SCIMITAR+). Participants were randomised to the SWAT using a 2:1 (intervention:control) allocation ratio. The primary outcome measure was the proportion of participants completing a CO breath measurement at the first SCIMITAR+ follow up time point (6 months). Secondary outcomes were withdrawing from follow-up after contact and time from assessment due date to completion. Analyses were conducted using logistic or Cox Proportional Hazards regression as appropriate. Results A total of 434 participants were randomised into this SWAT. Completion of the CO breath measurement at 6 months was 88.5% (n=247) in the intervention arm of the SWAT and 85.4% (n=123) in the control arm (Difference 3.1%, OR 1.29, 95% CI 0.71-2.33, p=0.41). There was also no evidence of a difference in the proportion of participants withdrawing from follow-up after contact (intervention n=7 (2.5%), control n=5 (3.5%); OR 0.76, 95% CI 0.23-2.44, p=0.64), nor in terms of proximity of 6-month visit completion to due date (HR 1.07, 95% CI 0.86-1.33, p=0.55). Conclusion It is unclear if contingent financial incentives increased rates of face-to-face follow-up completion within the SCIMITAR+ trial population. However, the sample size of this SWAT was constrained by the size of the host trial and power was limited. This SWAT adds to the body of evidence for initiatives to increase response rates in trials.

SCIMITAR+ Trial: A randomised study within a trial (SWAT) of a contingent financial reward to improve trial follow-up

Background: To evaluate the effectiveness of a contingent financial incentive (£10 note in addition to a routinely provided £10 voucher) versus no contingent financial incentive, on improving the retention rate in a randomised controlled trial (RCT). Methods: A two arm ‘Study within a Trial’ (SWAT) embedded within a host RCT (SCIMITAR+). Participants were randomised to the SWAT using a 2:1 (intervention:control) allocation ratio. The primary outcome measure was the proportion of participants completing a CO breath measurement at the first SCIMITAR+ follow up time point (6 months). Secondary outcomes were withdrawing from follow-up after contact and time from assessment due date to completion. Analyses were conducted using logistic or Cox Proportional Hazards regression as appropriate. Results: A total of 434 participants were randomised into this SWAT. Completion of the CO breath measurement at 6 months was 88.5% (n=247) in the intervention arm of the SWAT and 85.4% (n=123) in the control arm. The difference (3.1%) was not statistically significant (p=0.36; OR 1.29, 95% CI 0.71-2.33, p=0.41). There was also no evidence of a difference in the proportion of participants withdrawing from follow-up after contact (intervention n=7 (2.5%), control n=5 (3.5%); OR 0.76, 95% CI 0.23-2.44, p=0.64), nor in terms of proximity of 6-month visit completion to due date (HR 1.07, 95% CI 0.86-1.33, p=0.55). Conclusion: Contingent financial incentives did not statistically significantly increase rates of face-to-face follow-up completion within the SCIMITAR+ trial population. However, the sample size of this SWAT was constrained by the size of the host trial and power was limited. This SWAT adds to the body of evidence for initiatives to increase response rates in trials.