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ePaper created 2016-04-13, 11:38:23 | version 1.38.0
Dental Tribune United Kingdom Edition | 3/201612 TRENDS&APPLICATIONS Breath odour is the presence of odorous volatile organic compounds inthebreathofindividuals.Itisawide- spread problem, as it affects a high percentage of the adult population; 30 per cent of the global population suffersfromchronicoralmalodourand 74percentconsidersitanissue.1 Breath odour has strong social implications for the sufferer and it significantly affectsnormalsocialinteractions. Breathodourcanhavephysiolog- ical or pathological causes of intra- or extra-oral origin (Fig. 1). Physio- logical odour includes morning breath, which is transient and re- lated to low salivary flow during thenight.Otherlifestylefactorscan influence it too, such as smoking, as well as the consumption of alcohol or odoriferous foods and drinks (garlic, onion and cabbage, among others). These are fairly common reasonsforconcernintheadultpop- ulation, but can easily be rectified by modification of beverages and foods consumed, toothbrushing, mouthrinsesandtonguecleaning. Pathological malodour, however, is more challenging to treat. Extra- oral breath odour can arise from respiratory, gastrointestinal or metabolic issues, which cannot be addressed by oral hygiene, as these do not originate from the mouth.2–4 Mostcases,however,originatefrom the oral cavity . Breath odour from intra-oralcausesarisesfromvolatile sulphur and organic compounds (VSCs and VOCs, respectively) formed as a result of the degrada- tion of organic substrates by anae- robic bacteria on the dorsum of the tongue, particularly at the back of it.5,6 Itcanalsoresultfromgingivitis and periodontitis, and their com- bination with tongue bacteria. However, in individuals with good oral hygiene and gingival health, the main cause is the bacteria on thetongue(Fig.2a).4 Breathodouris generally assessed by organoleptic score, which is determined by a trained odour judge, who measures thestrengthoftargetodoursandex- pressesthevalueaccordingtoapre- defined scale from 0 (no odour) to 5 (strongmalodour). Anicheforbacterial biofilms The tongue has a very complex and rough surface structure cov- ered with flexible papillae (Fig. 2b). Those papillae vary in shape, size and distribution pattern and give thetongueasurfacewithnumerous crypts and fissures.7, 8 This consti- tutes a perfect microbial niche for anaerobic bacteria to thrive and form thick biofilms largely undis- turbed. Bacteria can degrade a com- plex mixture of amino acids and proteins from numerous origins (diet, debris, cells) with their com- plex enzymatic machinery. Partic- ularly the degradation of amino acids,suchascysteineandmethion- ine, produces VSCs with a very high odour power.9 The bacterial density on the tongue surface has been related to the degree of breath odour.10–12 For example, individuals withnoticeablebreathodour(above 2.5inthe5-pointorganolepticscale) have more than 1 × 108 bacterial colony-forming units per cm2 of the tongue, while individuals with lower organoleptic scores harbour lower bacterial numbers (approxi- mately 1 × 107).12 Therefore, in order to reduce breath odour in patients, the tongue bacterial density must bereducedandkeptatlowlevels. Treatment oforal malodour There are numerous over-the- counterproductsfororalmalodour andthesecanbedividedintochem- ical and mechanical treatments. Chemical treatments are mostly mouthrinsesspecificallydeveloped for oral malodour, containing a combination of antimicrobials and metal ions. Commonly used anti- microbials are chlorhexidine and cetylpyridinium chloride (CPC), which have a strong effect in killing bacteria. Metal ions, such as zinc, bind to sulphur compounds and form insoluble complexes (zinc sulphide) that are not volatile and arethereforenon-odoriferous.10,13–16 Another category of mouthrinses for malodour contains chlorine dioxide, which neutralises the sul- phur gases and oxidises VSCs, while the chlorite anions act as an anti- bacterialcompound.17 While mouthrinses have the potential to be very effective owing to their antibacterial and oral mal- odour-masking properties, they rarely provide a long-lasting result. They are effective for a few hours, but they have little effect on the tongue bacterial density.18, 10 A pos- sible cause of this limited effect on the tongue is that the active com- ponents of mouthrinses cannot reach the odour-producing bacte- ria. Biofilms that produce volatile gases are mostly located deep be- tween the tongue papillae (Fig. 2c), where mixing and diffusion of ac- tive ingredients are difficult owing to the small papillary spaces, the viscosity of salivary molecules and the low permeability of biofilms. Guidelines for the treatment of oral malodour by dental professionals emphasise the need for tongue cleaningusingscrapersorbrushes. Clinical studies have shown that the use of mechanical methods re- duces the tongue coating.10–21 How- ever, the effect on malodour is very short lived,19 which is probably due to the reduction of the bacterial nu- trients present in the tongue coat- ing rather than the reduction of the bacterialdensityitself.22 Thelimited amount of bacterial removal from thetongue’scomplexsurfaceisdue to the difficulty in reaching the biofilm between the tongue papil- lae. Moreover, as the tongue tissue is very flexible, the use of tongue scrapers could flatten the papillae, trapping the bacterial biofilm un- derneathandnotremovingit. Combinedapproach forall-dayfresh breath The use of mouthrinses in com- bination with mechanical inter- vention could help the active in- gredients penetrate deeper into the biofilm than when used alone, while simultaneously reducing the tongue coating and bacterial den- sity. The combined approach of chemical and mechanical interven- tion could have a synergistic effect onoralmalodourtodeliverfull-day Causes and treatment of breath odour By Dr Paola Gomez-Pereira,UK 3c 3d 3e 3a 3b Figs.3a–e: Philips SonicareTongueCare+ brush head,BreathRx,and sketch of MicroBristles and BreathRx cleaning between tongue papillae covered with biofilm. 1 2 Fig. 1: Classification of oral malodour (modified from Scully and Greenman).—Fig. 2a: Tongue with a slight coating.—Fig. 2b: Filiform and fungiform papillae histology of the human tongue (https://www.med.umich.edu/histology/giLiver/oralCavity.htm).—Fig.2c: Sketch of papillae with biofilm between releases ofVOCs to the oral cavity. DTUK0316_12-13_Pereira 12.04.16 12:06 Seite 1 12 DTUK0316_12-13_Pereira 12.04.1612:06 Seite 1