OK, so alcohol can get lodged in dental plates but is there anything else that can adversely affect an evidential breath alcohol reading? I’ve had another two queries about this, so I thought I’d add a bit more information.
Some sprays, such as nitrolingual sprays used to assist with certain heart conditions, and some asthma inhalers can also adversely affect breath alcohol readings. Some mouth washes and liquid medicines may also have an effect, depending on how they were used.
Some medicines have a warning on them that the patient should not operate machinery or drive because of possible adverse effects. Other medicines specifically say that they should not be taken with alcohol. These warnings do not mean that the blood (and hence) breath alcohol concentration will necessarily increase as the result of taking them; it means the effects felt may adversely affect driving or impair someone to properly operate machinery, including motor vehicles on the public highway. You could argue it may also impair the ability to safely operate a kettle and make a cup of tea. Symptoms such as dizziness can be unpredictable beasts, hence the warning labels.
Once again though, case circumstances will dictate whether or not any particular substance has adversely affected breath readings in a given case. Examination of the timeline of events as well as the printout from the breath testing device should be the keys as to whether the breath alcohol result in a given case is reliable or not.