9Saliva The Composition of Saliva Composition Unstimulated Stimulated Water and ElectrolytesWater % %Solids 0.45% 0.47%Flow Rate(ml/min) 0.32 0.84pH 0.17Sodium (mmol/L) 11.74Potassium 2.70Bicarbonate 5.06Phosphate 0.55Chloride ± 7.38Calcium ± ± 0.35Na+& Cl-K+Saliva and Oral Health Edgar M, Dawes C, O’Mullane D Eds. 4th Ed 2012
10Saliva The Composition of Saliva Water and Electrolytes Na+& Cl- K+ Changes in the salivary flow rate and main electrolytes in whole saliva secreted over 20 minutes in 12 subjects while they chewed a piece of sugar-free gum, preceded by a five-minute collection of unstimulated saliva. mmol/L: Millimoles/liter. mL: Milliliters. Na: Sodium. K: Potassium. Ca: Calcium. Cl: Chloride. HCO3: Bicarbonate. Pi: Inorganic phosphate. Source: Dawes and Dong.18Dawes, C. JADA 2008;139:suppl 2:18S-24S
11Saliva Water Solids Flow Rate pH Organic Total protein MUC5B MUC7 AmylaseLactoferrinStatherinAlbuminGlucoseLactateUreaUnstimulated Stimulated99.55 % %0.45% %0.32 ± ± 0.847.04 ± ± 0.171630 ± ± 290830 ± ± 200440 ± ± 330317 ± ± 3908.4 ± ± 4.74.93 ± 0.6151.2 ± ± 53.079.4 ± ± 27.10.20 ± ± 0.173.57 ± ± 0.92± 1.64SalivaSaliva and Oral Health, Edgar M. Dawes C., O’Mullane, D. Eds. 4th Ed, 2012
12Saliva The Functions of Saliva Resting Saliva Oral Protection System SecretionSubmandibular %Parotid %Sublingual ~ 7-8%Minor glands ~ 7-8%Oral Protection System- Secretion rate: mls/min- Texture: Viscous (mucus)- Rich in mucins- pH value- Functions: Coating of the teeth: salivary pellicle- Lubrication of oral mucosaStimulated SalivaParotid %Submandibular %-Sublingual ~ 10%and minor glandsOral Repair System- Secretion rate: 1-3mls/min- Consistency: Thin (serous)- Rich in minerals- pH value:- Functions: Clearance, buffer system, remineralisation
13Saliva Salivary Functions The Multiple Functions of Saliva Buffering CarbonicanhydrasesHCO3Anti-BacterialsIgA PeroxidasesDigestionlipase, amylasemucinsAnti-Viral Cystatins MucinsSalivaryFunctionsAnti-FungalCandida: HistatinsMineralizationCa, Fl, PO4LubricationViscosity ElasticityMucinsStatherinsTissue CoatingMucins, PRPsAmylasesFigure adapted from M.J. Levine. 1993
14Saliva The Major Functions of Saliva Digestion & Taste Protection ManipulationDissolve solidsStarch digestion(amylase)Gustatory sensationFacilitate chewingSwallowingBolus formationBuffer - plaque acids(foods) extrinsic acids(reflux) intrinsic acidsAntibacterialOral ecology balancePathogen defenceMouth clearance/rinsingFood and bacteriaPrevent demineralisationAid remineralisationHydrates mucousmembraneAttachment -Saliva proteins coat enamel surface and allow specific absorption of primary colonisersFood -Saliva may act as a carbon source and select for healthy bacterial balance
16Biofilm 1st Phase: immediately to approximately 4 hours Formation of aquired pellicle from salivary glycoproteins and maturation. Early colonisation from initial bacteria mainly Streptococcus strains.2nd Phase: 4 to 48 hoursColonisation of predilection sites, i.e. fissures, iatrogenic retention factors (restorations/overhangs/ortho brackets) and white spots.3rd Phase: 3 to 7 daysAerobic bacterial metabolic products compromise the hard dental tissues; anaerobic bacterial metabolic products compromise the soft tissues.4th Phase: 7 to 14 daysMature plaque biofilm is established that consists of sessile bacteria firmly attached to the hard dental tissues and planktonic (floating) bacteria.(König 1987)
17Biofilm The Formation of Biofilm Quorum sensing Fl- Late Colonizers T.denticolaFl-AAPGLate ColonizersT.forsythiaC.achraceaC.sputigenaC.gingivalisSalivary receptors in salivary pellicle provide binding matrix for early colonising bacteria.Early colonisers: include: Streptococcus, Actinomyces and Capnocytophaga strains ( in addition to many other early bacteria).Late colonisers include: AA, PG, T.forsythia. T.denticola (amongst others).Late colonisers bind to the early colonisers. Bacteria within the biofilm are able to bind to bacteria of different species.CLICK FOR FL RESISTANCE DEMO: -The biofilm protective matrix makes them resistant to antibiotics, antimicrobials, and host response.Recent research has shown micro-organisms in biofilm can adapt to Fl exposure and become Fl resistant. (Ten Cate 2013)Limiting Fl penetration of the biofilm and salivary pellicle and reducing the protective effects of Fl.A.orisA.israeliiA.naeslundiiEarly ColonizersStrep. oralisStrep. sanguisStrep. mitisStrep. gordoniiStatherin-amylaseProline-rich proteinSalivary agglutininSialylated mucinsFl- resistanceSalivary PellicleEnamel Surface
18Sugar-Free Gum Salivary Flow Rate Saliva flow rates under stimulation Saliva flow (ml in 20 min)Un-stimulated salivaStimulated saliva after chewing paraffinStimulated saliva after chewing sugar-free gum- Chewing gum increases the saliva flow rate up to 10 times.- “Empty” chewing, without flavor additive (e.g., paraffin), only stimulates up to 5 times.- Chewing sugar-free gum with flavor additive improves flushing and accelerates the removal of soluble compounds.(Edgar 1993)
19Sugar-Free Gum Salivary Flow Rate Polyol-sweetened gum stimulates the production of saliva by two mechanisms:- Gustatory stimulation (taste buds)- Masticatory action (periodontal mechanoreceptors)(Dawes and Macpherson. 1992)
20Sugar-Free Gum Salivary Flow Rate Salivary stimulation lasts more than 2 hours with SF gum.- Flavour and chewing increase salivary flow.Unstimulated flow rates of less than 0.1 mL/minute are considered evidence of hypo-salivation(Dawes, C., et al. Arch Oral Biol 2004, 49, )
21Sugar-Free Gum Salivary Flow Rate and Xerostomia* Sugar-free gum may have benefits in older and medically-compromised patientsChewing sorbitol gum increased saliva flow rates and neutralized plaque pH drop from sucrose in subjects with xerostomia.1,2- 69% of cancer patients with xerostomia preferred chewing gum to artificial saliva3; 60% of hemodialysis patients preferred gum to saliva substitutes.4- Gum chewing (12 months, 2x/day) increased stimulated saliva flow rates in 111 frail older people.5A 6 month study in 186 older (community-dwelling) adults showed significant improvements in plaque and gingival indices, but not saliva flow6; self-perceived oral health status improved significantly in the gum group.Module 2 will discuss the diagnosis, treatment and management of Xerostomia in greater detail.Markovic N; Abelson DC; Mandel ID (1988): Gerodont. 7: 71-75Abelson DC, Barton J, Mandel ID (1990): J Clin Dent 2: 3-5Davies AN (2000): Palliat Med 14:Bots CP, Brand HS, et al (2005): Palliat Med 19:Simons D, Brailsford SR, Kidd EAM, Beighton D (2002): J Am Geriatr Soc 50:Al-Haboubi M, Zoitopoulos L, Beighton D, Gallagher JE (2012): Community Dent Oral Epidemiol 40:* Module Two
22Sugar-Free Gum Oral Clearance Relies on swallowing and flow rate. Higher salivary flow rate = increased clearance.Unstimulated flow rate < 0.2ml/min = prolonged clearance.Prolonged clearance = greater risk of caries.Greater risk of acid erosion.151050.20.40.60.81.0Unstimulated Flow Rate UNSTFR(ml/min)Halftime(min)Chewing SFGum increases clearance rate and reduces contact time between acidic/sugary foods and the hard tissues.This decreases risk of caries and erosion.Effect of changes in the UNSTFRon the clearance halftime of sucroseSaliva and Oral Health, Edgar M. Dawes C., O’Mullane, D. Eds. 4th Ed, 2012
23Sugar-Free Gum Buffering Capacity Fast flowing saliva neutralises plaque (pH value increases).Buffer capacity is the ability to neutralise acids (buffering).The pH value is raised due to the increased concentration of bicarbonate in stimulated saliva.(Bicarbonate increases from 5.47 unstimulated to 16.03mmol/L in stimulated saliva).Increased flow rate exposes hard tissues to low pH for a shorter period.(Flow rate increases from 0.32 ml/min unstimulated to 2.08ml/min in stimulated saliva).Saliva stimulation and buffering of acids by chewing gumpH value10% sugar solutionChewing gum with sugar substituteTime in minutes(Stoesser 1996)Chewing SFGum increases saliva flow rate and increases pH value of saliva through increased bicarbonate concentrations.This decreases exposure time to acids from food and plaque in addition to increasing the buffering capacity of saliva.
24Saliva stimulation from chewing gum helps to neutralise plaque acids CariesPlaque pHSaliva stimulation from chewing gum helps to neutralise plaque acidsFactors affecting plaque acids- Fermentable carbohydrates.Oral bacteria produce:Extracellular polysaccharides in the presence of excess sucrose.Glucans increase plaque adhesion and thickness.Fructans produce acid metabolites.Intracellular polysaccharide stores provide ongoing acid production in resting plaque.Plaque pHTime (min)The pH of plaque is raised more quickly following a sucrose challenge.Manning RH, Edgar WM (1993) Brit Dent J 174: 241-4
27Caries Demineralisation- Remineralisation Demineralisation shifts to remineralisation by the use of fluoridation and saliva activation. Saliva provides the medium for remineralisation.Supersaturation of saliva with ionic Ca and Pi, can effectively help remineralise incipient caries lesions.- Fluoride inhibits demineralisation by penetrating and coating enamel crystals to prevent dissolution.- Enhancing remineralization resulting in enamel with a higher Fl content and lower acid solubility.
29Redrawn from Featherstone BMC Oral Health 2006 6(Suppl 1):S8 CariesTHE CARIES BALANCEPATHOLOGiCAL FACTORSAcid producing bacteriaFrequent eating/drinking of fermentable carbohydratesSubnormal saliva flow and functionPROTECTIVE FACTORSSaliva flow and components-Fluoride-remineralisationwith calcium and phosphate- Antibacterials: chlorhexidine, xylitolCARIESNO CARIESRedrawn from Featherstone BMC Oral Health (Suppl 1):S8
30Caries Reduction Studies Clinical Caries Studies Chewing SF gum reduces caries in prospective 2-3 year clinical trials.Clinical Caries Studies- Three year study in children with high caries prevalence showed caries-protective benefit of sugar-free gum (Beiswanger et al. 1998)Three year study, Puerto RicoN = 1402 subjects, age 8-13Chewed gum 3 x/day for 20 min after meals7.9% fewer DMFS in all subjects and 11.0 fewer in high-caries subjects.- Another two year study confirmed caries-protective benefit in lower-caries prevalence population (Szöke et al, 2001)Two year study, Hungaryn = 547 subjects, age 8-13Chewed gum 3 x/day for 20 min after meals or no gumResults show 38.7% reduction in DMFS increment after 2 yearsINCREMENTAL DMFS
31Reduction of Caries Incidence (%) Reduction StudiesTabulated Summary of Data from Pertinent Human Intervention StudiesStudyIntervention (n/N)Control (n/N)Reduction of Caries Incidence (%)Möller 1973Sorbitol gum 3x/day after meals. 161/313No gum. 152/31310%Glass 1983Sorbitol gum 2x/day. 269/540No gum. 271/5402%Kandelman 199015% Xylitol gum 90/274No gum. 97/27461%65% Xylitol gum 87/27466%Mäkinen 1995aSorbitol gum pellets 2x1.3g, 5x/day 129/1135No gum. 121/113517%3:2 xylitol/sorbitol pellets, 5x/day 120/113544%Mäkinen 1996Sorbitol stick, 1, 5x/day. 63/471No gum. 86/47128%Beiswanger 1998Sorbitol gum, 3x/day after meals. High risk subjects, intention to treat, 607/1256No gum. 649/125612%Szöke 2001Sorbitol stick, 3x/day after meals. Including white spots, 269/547No gum. 278/54733%Peng 2004Sorbitol/xylitol/carbamide gum, 4x/day. 363/733No gum. 370/73342%Machiulskiene 2001Sorbitol gum, 5x/day after meals. 68/432No gum. 80/32025%
32Caries Reduction Studies Caries Reduction and Gum - Conclusions Multiple studies support the anti-caries benefits of sugar-free gum chewed after eating.The majority showed reductions in the range 20-60%.Systematic reviews have also supported this position (eg Mickenautsch et al, 2007; Deshpande and Jadad , 2008)- Studies have been reviewed by expert panels resulting in supporting reviews and statements from regulatory and authoritative bodies (FDA, FDI, ADA, EFSA, etc).
38Sugar free gum may help prevent erosion and erosive tooth wear* RemineralisationSugar free gum may help prevent erosion and erosive tooth wear*Exogenous dietary acids occur at much lower pH values in comparison toplaque acids.- Saliva stimulation from chewing gum:- Increases the rate of mouth clearance from acidic food or drink1.- Stimulates saliva production2.- Increases levels of bicarbonate and calcium ions in saliva3.Aids in more rapid remineralisation of the enamel surface following anacid challenge4.*Initial study suggests salivary stimulation may help5.*Direct clinical evidence pending1.Trlolo P et al:J Dent Res 1990:69(1Suppl);1362.Dawes C et al:Arch Oral Biol 2004;49(8):3.Dawes C et al: Arch Oral Biol. 1995;40:4.Wefel JS et al:J Dent Res 1989;68(1supp):214.5. Rios D et al: Caries Res 2006;40:
40Clinical Assessment Examination Diet Acids : Food, drinks and frequency.Sugars: Added, hidden and frequency.Timing: Avoid before bed time - reduced salivary flow.Oral HygieneTooth brushing technique, bristle type.Toothpaste abrasives.Bacterial acids, plaque scores, demineralisation.Fluoride ExposureFrequencyAge appropriate fluoridationSalivaQuality: serous, mucoid, frothy.Quantity: adequate and reaches all areas of the mouth.Buffering capacity.
42Basic Erosive Wear Examination Clinical AssessmentRisk Assessment ToolsBasic Erosive Wear Examination0 No surface lossInitial loss of enamel surface texture2* Distinct defect, hard tissue loss lessthan 50%of the surface area3* Hard tissue loss more than 50% of thesurface area*Dentine is often involvedBEWE: a new scoring system for scientific and clinical needs. Clin Oral Investig March; 12(Suppl 1): 65–68.BEWE Index
43Chairside Testing Saliva 1. Measuring the saliva flow rate (ml/min) Saliva categories Saliva flow rates (ml/min)Normal flow rateReduced saliva flow rateMouth dryness (xerostomia) <0.52. ConsistencyVisual inspectionCategories CharacteristicsStrongly increased viscosity Sticky frothy salivaIncreased viscosity Frothy bubbly salivaNormal viscosity Watery clear saliva3. Measuring the buffer capacityThe change in color on the test strip is compared with the sample card and this indicates the buffer capacity:Low Medium High
45Recommendations Sugar Free Gum Chew SFG for 20mins after sugar or acid challenge.Encourage regular saliva stimulation inbetween meals.Chew sugar free gum, to increase thesaliva flow rate.Dental care on the go: chewing sugar free gumcan:- Provide mouth clearance- Help prevent plaque accumulation.- Increase saliva buffering capacity.- Decrease plaque pH.- Decrease caries and erosive potential.
46Conclusions Saliva is the most important part of the body’s own protective systems for maintaining oral health. Reduced saliva quantity and quality increase the risk of caries, erosion, xerostomia and interfere with the ecological balance in the mouth. Informing the patient and activating the saliva’s protective function for the mouth and teeth is the basis of a modern, prevention-oriented treatment strategy. It has been scientifically proven: saliva stimulation by chewing sugar free gum helps to increase the saliva flow-rate up to tenfold, which can reduce the risk of caries by up to 40%.