Validation of a sensor system for the measurement of breath ammonia using selected-ion flow-tube mass spectrometry.

The measurement of trace breath gases is of growing interest for its potential to provide non-invasive physiological information in health and disease. While instrumental techniques such as selected-ion flow-tube mass spectrometry (SIFT-MS) can achieve this, these are less suitable for clinical application. Sensitive sensor-based systems for breath ammonia could be more widely deployed, but have proven challenging to develop.

Discovery, development and exploitation of steady-state biofilms.

Early in vitro biofilm models go back even beyond the invention of the word 'biofilm'. In the dental field, biofilms were simply known as dental plaque and many of the first in vitro models were termed 'artificial mouth microcosm plaques'. The purpose of this review is to highlight important elements of research from over the years regarding in vitro biofilm models, including data from our own laboratories.

Short- and Long-Term Effects of a Dentifrice Containing Dual Zinc plus Arginine on Intra-Oral Halitosis: Improvements in Breath Quality.

Objectives: These studies aimed to assess the short-term (12-hour, single use) and long-term (four weeks, continuous use) efficacy of a new Dual Zinc plus Arginine dentifrice against intra-oral halitosis versus a negative control.

Methods: Two clinical studies were conducted to assess the dentifrice: a four-week, continuous use parallel design versus a negative control and a single use crossover design versus a negative control. Both studies used organoleptic and hedonic odor judge scores measured 12 hours overnight after product use as the primary efficacy variable.

Volatiles from oral anaerobes confounding breath biomarker discovery.

The levels of compounds in exhaled mouth air do not necessarily reflect levels in the systemic circulation as bacteria can bio-transform substrates to produce compounds within the mouth. This should be of concern to researchers measuring breath volatiles with the aim of diagnosing systemic or metabolic conditions as very little is known about the origin of many compounds detected on the breath. This pilot study investigated the production of volatile compounds by bacterial communities present within the mouth.

Tongue biofilm areal density and tongue coating index.

Two methods have been employed to measure the amount of tongue biofilm in humans: (1) areal density of microbes (cfu cm(-2)) (tongue scrape from a known/measured area), or (2) a tongue-coating index, where a human judge assesses the amount of 'coating' by visual inspection. The two methods were compared, both on human volunteers and on artificial biofilms. Fusobacterium nucleatum (Fn), Prevotella intermedia (Pi), Streptococcus mutans (Sm) and Peptostreptococcus micros (Pm) were obtained from stock cultures.