Post-brushing rinsing for IN BRIEF • Raises awareness of the potential for post-tooth brushing rinsing behaviours OPINION the control of dental caries: to either reduce or enhance the effectiveness of fluoride toothpaste. • Highlights the lack of high-quality evidence to support guidance for post- exploration of the available tooth brushing rinsing behaviours. • Provides recommendations for post-tooth brushing rinsing behaviour based on evidence to establish what advice consensus views of dental experts. we should give our patients N. Pitts,1 R. M. Duckworth,2 P. Marsh,3 B. Mutti,4 C. Parnell5 and D. Zero6 Post-tooth brushing rinsing behaviours have the potential to either reduce or enhance the effectiveness of fluoride toothpaste and show wide variation in the general population. There is a lack of high-quality evidence to support definitive guidance in this area. However, the currently available international guidelines provide consistent recommendations despite the limited evidence. To explore the available evidence base and recommendations on optimal post-brushing rinsing behaviour relating to the use of both water and mouth rinses, a meeting was held between the authors and other experts. This paper reports the consensus views of those present at the meeting concerning what advice we should give our patients. A full list of meeting attendees is provided at the end of this article. INTRODUCTION mouth rinse or antimicrobial mouth rinse) consumption and frequency to restrict Oral care products for home-use play an could potentially either reduce or enhance periods of acidic challenge to teeth, as important part in the prevention and con- the effectiveness of fluoride toothpaste. well as a range of interventions to increase trol of oral diseases such as caries and Despite this important interaction, this is tooth resistance. Furthermore, oral disease periodontal disease. Fluoride toothpaste an area in which there is little guidance for can be prevented not only by directly is the most widely used topical fluoride the patient or the dental practitioner. The inhibiting the putative pathogens, but modality for caries prevention and control consensus recommendations described in also by interfering with the environmental worldwide. There is a body of high-quality this paper are based on an exploration of factors driving the selection and enrich- evidence regarding the optimal concen- the different types of evidence currently ment of these bacteria. Several traits of tration of fluoride in toothpaste for caries available and the knowledge gaps that cariogenic bacteria make good targets for prevention, the frequency of brushing and, exist. Although the range and quality of components of mouth rinses that aim to to a lesser extent, the amount of tooth- evidence on optimal post-brushing rins- control plaque or tooth demineralisation. paste to be used (particularly in young ing behaviour relating to the use of both These targets include: inhibition of sugar children). Rinsing with water or a mouth water and mouth rinses is variable, recom- transport, inhibition of rapid production of rinse after tooth brushing is also a com- mendations from professional organisa- acid, interference with the acid tolerance mon practice. Ideally oral hygiene proce- tions on post-brushing rinsing appear to of the bacteria and blocking synthesis of dures should complement each other, yet be consistent. intracellular and extracellular polysac- the method of rinsing and the product used The goal of oral health maintenance is to charides. Clearly any agent in a mouth for rinsing (for example, water, fluoride prevent and control caries and other oral rinse must be active against the selected diseases through a multifaceted approach, target; capable of penetrating and then which for dental caries takes into account being retained within the biofilm; must not 1*Director of the Centre for Clinical Innovations and tooth resistance, biofilm, diet and rate of adversely affect oral microbial ecology and Professor of Dental Health, University of Dundee, Dundee; 2Honourary Lecturer, Newcastle University, disease progression. must not generate resistance or select for Newcastle upon Tyne; 3Professor of Oral Microbiology, Plaque biofilms develop in a structured exogenous pathogens.1 University of Leeds, UK; 4Associate Director R&D Prod- uct Development, Johnson & Johnson, Germany; 5Re- way over time. The developing biofilm Antiplaque agents can reduce bio- searcher, Oral Health Services Research Unit, University synthesises extracellular polymers that film formation by altering the proper- College, Cork, Ireland; 6Director of the Oral Health Research Institute, Professor and Chair Department of form a functional matrix, which can mod- ties of the surface at risk of colonisation Preventive and Community Dentistry, Associate Dean ify the movement of molecules within the and/or removing established biofilm. for Research, Indiana University School of Dentistry, Indianapolis, IN, USA biofilm. Mature plaque is more difficult to Antimicrobial agents may kill target *Correspondence to: Professor Nigel Pitts remove than a newly formed biofilm and organisms, but they can also be effective Email: [email protected] may contain more pathogenic bacteria.1 if they slow bacterial growth and/or inhibit Refereed Paper Strategies to control caries include cariogenic traits. For example, effective Accepted 1 March 2012 DOI: 10.1038/sj.bdj.2012.260 effective oral hygiene practices to reduce agents may slow plaque growth/regrowth ©British Dental Journal 2012; 212: 315-320 biofilm development, reduction in sugar or they may prevent development of a BRITISH DENTAL JOURNAL VOLUME 212 NO. 7 APR 14 2012 315 © 2012 Macmillan Publishers Limited. All rights reserved. OPINION damaging pH within the biofilm, thereby (direct effect). In addition, by reducing mouth rinses and dentifrices, a further reducing the acidic challenge to the tooth environmental acidification in biofilms, question concerns whether this depend- and eliminating the acidic environment fluoride removes the conditions that ence is related to applied fluoride con- that selects for cariogenic bacteria. Mouth give S. mutans a competitive advantage centration or applied fluoride amount. A rinses are effective vehicles for deliver- (indirect effect).4 study by Duckworth and colleagues dem- ing antimicrobial or antiplaque agents, Salivary fluoride clearance is a com- onstrated that fluoride concentration in although the pharmacokinetics and mode mon surrogate used to assess the poten- mouth rinses appears to be a more impor- of action of any active ingredient must be tial anticaries efficacy of fluoridated oral tant factor than applied fluoride volume consistent with this delivery route. care treatments. A typical mean salivary in determining the elevation of oral Historically, the anticaries benefits of fluoride clearance curve is formed by plot- fluoride levels following topical fluoride fluoride have been proven for toothpastes, ting salivary fluoride clearance on a loga- use.7 Therefore, application of a fluoride mouth rinses, gels and drinking water, etc. rithmic scale against time. The resultant dose in a smaller volume and at a higher Fluoride works in a range of ways includ- curve is typically biphasic, with an initial concentration than the current norm, ing acidification of the bacterial cell inte- rapid drop in fluoride concentration over may increase efficacy without increasing rior, which disrupts enzyme systems and the first 30 min followed by a slow decline. adverse effects.7 inhibits growth of the organism.2 The initial fall reflects salivary wash-out of Rinsing habits also play an important A group of experts gathered to examine unbound fluoride. During the latter phase, role in the oral retention of fluoride from and document the available evidence and it is believed that fluoride is released from dentifrices and may, in turn, affect their the gaps in this field through a series of an oral fluoride reservoir. Labile fluoride, clinical efficacy.8 Approximal sites benefit presentations given by the authors. The stored in oral fluoride reservoirs at the significantly more from fluoridated rinses experts then formulated consensus state- time of topical treatment application, may than the more exposed buccal sites in chil- ments relating to rinsing behaviour and maintain a prolonged protective effect dren and adults, but this is affected by the the prevention of dental caries. The evi- against dental caries.5 rinsing technique used.9,10 dence for these statements and the con- Use of a fluoride mouth rinse affects oral sensus statements themselves are provided retention of fluoride.6 Duckworth and col- THE ROLE OF FLUORIDE IN MOUTH RINSES in this publication. leagues demonstrated that the inclusion of 100 ppm fluoride in a mouth rinse com- Several systematic reviews have evalu- SALIVARY FLUORIDE CLEARANCE pensated for the loss of oral fluoride after ated the effectiveness and safety of flu- AND MOUTH RINSES an oral hygiene regimen that combined oride mouth rinses in the prevention of Oral hygiene procedures should ideally brushing with fluoridated toothpaste fol- dental caries. A review by Marinho and complement one another. Mouth rinses lowed by rinsing with a non-fluoridated colleagues11 of 34 studies involving 14,600 are well accepted and widely used in mouth rinse.6 This study further showed children and adolescents concluded that combination with brushing and flossing. that rinsing with a fluoridated mouth rinse