435J. Acad. Indus. Res. Vol. 1(8) January 2013ISSN: 2278-5213REVIEW ARTICLEExtrinsic stains and management: A new insightSruthy Prathap, H. Rajesh, Vinitha. A. Boloor and Anupama. S. RaoDept. of Periodontics, Yenepoya Dental College, Nithyananda Nagar Post, Deralakatte, Mangalore-575018, Karnataka, [email protected]; 91 9980433489AbstractTooth discoloration is a frequent dental finding associated with clinical and esthetic problems. It differs inetiology, appearance, composition, location and severity. Knowledge of the etiology of tooth staining is ofimportance to dental surgeons in order to enable a correct diagnosis. The practitioners should also have thebasic understanding of the mechanism of stain formation before carrying out any treatment procedures whichwill facilitate better treatment outcomes. Recently there have been advancements in the various treatmentoptions in this field. This article is a comprehensive review on extrinsic stains and the treatment modalities.Keywords: Tooth discoloration, esthetic problems, tooth staining, treatment outcomes, extrinsic stains.IntroductionIt is widely recognized that today’s youth andappearance oriented culture prizes an attractive smileand white teeth, with sales of whitening products risingdramatically in the past decade. Some of these productsare sold as ‘over the counter products’ and have noprofessional involvement in their application. The correctdiagnosis for the cause of color discoloration is importantas, invariably, it has profound effect on treatmentoutcomes. It would seem reasonable, therefore thatdental practitioners have an understanding of theetiology of tooth color discoloration in order to make adiagnosis and enable the appropriate treatment to becarried out (Aryan, 2005). Dental stains differ in etiology,appearance, composition, location, severity and degreeof adherence. Attraction of material to the tooth surfaceplays a critical role in the deposition of extrinsic dentalstains. However the mechanism that determines theadhesion strength is not completely understood (Tirth etal., 2009).Normal variations in tooth color: A basic understanding ofthe elements of tooth color is important for many aspectsin dentistry. Teeth are typically composed of variouscolors and a gradation of color occurs in an individualtooth from gingival margin to the incisal edge of thetooth. Near the gingival margin, tooth often has a darkerappearance because of close approximation of thedentine below the enamel. In most people canine teethare darker than central and lateral incisors and youngpeople characteristically have lighter teeth, particularly inthe primary dentition. Teeth become darker as aphysiological age change; this may be partly caused bylaying down of secondary dentin, incorporation ofextrinsic stains and gradual wear of enamel allowing agreater influence on color of the underlying dentine. Alsoand tooth wear and gingival recession can directly orindirectly affect tooth color. The science of color isimportant in dentistry with regard to color perception anddescription, and can be improved with training. Youth Education and Research Trust (YERT)The viewing conditions are extremely important andvariables such as the light source, time of day,surrounding conditions and the angle of tooth viewedaffects the apparent tooth color. Light is composed ofdiffering wavelengths and the same tooth viewed underdifferent conditions will exhibit a different color, aphenomenon known as metamerism (Watts and Addy,2001).Classification of tooth discolorationIntrinsic discoloration: Intrinsic discoloration occursfollowing a change to the structural composition orthickness of the dental hard tissues. The normal color ofteeth is determined by the blue, green and pink tints ofthe enamel and is reinforced by the yellow through thebrown shades of dentine beneath. A number of metabolicdiseases and systemic factors are known to affect thedeveloping dentition and cause discoloration as aconsequence. Local factors such as injury are alsorecognised.1. Alkaptonuria.2. Congenital erythropoietic porphyria.3. Congenital hyperbilirubinaemia.4. Amelogenesis imperfect.5. Dentinogenesis imperfect.6. Tetracycline staining.7. Fluorosis.8. Enamel hypoplasia.9. Pulpal haemorrhagic products.10. Root resorption.11. Ageing.Extrinsic discoloration: Extrinsic color discoloration isoutside the tooth substance and lies on the tooth surfaceor in the acquired pellicle.The origin of the stain may be:1. Metallic.2. Non-metallic.Sruthy Prathap et al., 2013

436J. Acad. Indus. Res. Vol. 1(8) January 2013Table 1. Types of stains, source, appearance and common sites.Types of stainsBrown stainBlack stainBlack stainOrange stainGreen stainMetallic stainYellowish brown stainsYellowGolden brown stainsViolet to blackRed-blackSource and predisposing factorsThe color is due to tannin. Intake of coffeeand tea. Causes-insufficient brushing.Inadequate cleansing action of dentifrice.Chromogenic bacteria.(1) Coal tar combustion products due tosmoking.(2) Penetration of pits and fissures, enameland dentine by tobacco juices.Iron containing oral solutions.Exposure to iron, manganese, silver.More common in woman, may occur inexcellent oral hygiene. High tendency forrecurrence:(1) Associated with low incidence of cariesin children.(2) Chromogenic bacteria-e.g. Grampositive rods-Actimomyces speciesBacteriodes melaninogenicus.Iron containing oral solutions.Chromogenic bacteria Serratia marcescens,Flavobactraium lutescens. Exposure tochromic acid fumes in factory workers(Manuel et al., 2010).Children are frequently affected due toinadequate daily plaque removal,chromogenic bacterial deposits ordecomposed hemoglobin.(i)Fluorescent bacteria- Penicillium.(ii)Fungi-Aspergillus.(iii) Associated with children with T. B. orcervical lymph node.3) Copper salts in mouth rinse (Manuelet al., 2010).4) Exposure to copper and nickel in theenvironment in factory workers (Manuelet al., 2010).This type of stain is caused by metals andmetallic salts. Metals are penetrated intotooth substances and produces permanentdecolonization or they bind with pellicle andproduce surface stain.Source of metals:(I) Introduction of metals into oral cavity.(II) Metal containing dust inhalation byworker.(III)Oral administration of drugs.Chlorhexidine has affinity for sulfate andacidic groups such as those found inpellicle, plaque constituents, carious lesionand bacterial cell wall. So it is retained intooral cavity and stained oral tissues(Manuel et al., 2010).Essential oil and phenolic mouth rinse(Manuel et al., 2010).Due to use of stannous fluoride (Mosby'sDental Dictionary, 2008).Presence of potassium permanganate inthe mouth rinses (Manuel et al., 2010).Use of betel leaves and nuts commonlyseen in adults and children in the EasternHemisphere, where betel leaves and nutsare used as stimulants (Mosby's DentalDictionary, 2008). Youth Education and Research Trust (YERT)Appearance on the tooth surfaceThin, translucent, acquiredbacteria free pigment pellicle.These are tenacious dark brownor black with browndiscoloration.This is a thin black line, firmlyattached on tooth surface.Common sites(1) Buccal surface ofmaxillary molars.(2) Lingual surface ofmandibular incisors.(1)Involves all the teeth.(2) Common on pits andfissures.(1) Near the gingivalmargin of facial andlingual surface of a tooth.(2) Diffuse patch on theproximal surface may beseen.Both facial and lingualsurface of anterior teeth.These are green or greenishyellow stains of considerablethickness. This type of stain isconsidered as stained remnantsof enamel cuticles.Some metals that cause’sstains:Copper dust-Green stainIron dust-Brown stainMagnesium-Black stainSilver- Black stain Iodine- Blackstain Nickel- Green stain.Metal penetrating into toothsubstance causes permanentdiscoloration where as that bindwith pellicle causes surface stain(Manuel et al., 2010).Yellowish brown to brownish.The stains are not permanent innature. It can be removed withproper brushing with dentifrice.Thick, hard, dark brown or blackextrinsic stain left on the teethafter chewing the leaves of thebetel palm (Mosby's DentalDictionary, 2008).Facial surface ofmaxillary anterior teeth.Generalised appearanceon all the teeth.(i)Cervical andinterproximal area of theteeth.(ii) Plaque and otherrestorations.(iii) Dorsum of tongue.Facial, lingual andocclusal surfaces of bothanterior and posteriorteeth.Sruthy Prathap et al., 2013

437J. Acad. Indus. Res. Vol. 1(8) January 2013Internalised discoloration: Internalised discoloration is theincorporation of extrinsic stain within the tooth substancefollowing dental development. It occurs in enamel defectsand in the porous surface of exposed dentine. The routesby which pigments may become internalised are:1. Developmental defects.2. Acquired defects.a) Tooth wear and gingival recession.b) Dental caries.c) Restorative materials (Manuel et al., 2010).Extrinsic tooth discoloration: The causes of extrinsicstaining can be divided into two categories;a) Direct extrinsic tooth staining: Those compoundswhich are incorporated into the pellicle and produce astain as a result of their basic color.b) Indirect extrinsic tooth staining: Those which lead tostaining caused by chemical interaction at the toothsurface.Direct extrinsic tooth staining has a multi-factorialaetiology with chromogens derived from dietary sourcesor habitually placed in the mouth (Fig. 1). These organicchromogens are taken up by the pellicle and the colorimparted is determined by the natural color of thechromogen. Tobacco smoking and chewing are known tocause staining, as are particular beverages such as teaand coffee (Fig. 2 and 3). The color seen on the tooth isthought to be derived from polyphenolic compoundswhich provide the color in food (Pearson, 1976). Indirectextrinsic tooth staining is associated with cationicantiseptics and metal salts. The agent is without color ora different color from the stain produced on the toothsurface. Interest in the mechanisms of extrinsic toothstaining was rekindled in 1971 with the observation byFlotra et al. (1971) that tooth staining increases with theuse of chlorhexidine (Fig. 4).Fig. 1. Stains due to betel nut.Fig. 2. Smoking stains.Fig. 3. Tobacco stains.Classification of extrinsic tooth stainingExtrinsic tooth discoloration has usually been classifiedaccording to its origin, whether metallic or non-metallic(Gorlin and Goldman, 1971).Non-metallic stains: The non-metallic extrinsic stains areadsorbed onto tooth surface deposits such as plaque orthe acquired pellicle. The possible aetiological agentsinclude dietary components, beverages, tobacco,mouthrinses and other medicaments. Chromogenicbacteria have been cited in children (Fig. 5 and 6).Particular colors of staining are said to be associatedwith certain mouths, for instance, green and orange inchildren with poor oral hygiene and black/brown stains inchildren with good oral hygiene and low cariesexperience (Theilade et al., 1973). Conclusive evidencefor the chromogenic bacterial mechanism has not beenforthcoming. The most convincing evidence for theextrinsic method of tooth staining comes from thediffering amount of stain found in a smokers andnon-smokers (Ness et al., 1977). Youth Education and Research Trust (YERT)Fig. 4. Chlorhexidine stains.Sruthy Prathap et al., 2013

438J. Acad. Indus. Res. Vol. 1(8) January 2013Metallic stains: Extrinsic staining of teeth may beassociated with occupational exposure to metallic saltsand with a number of medicines containing metal salts(Addy and Roberts 1981). The characteristic blackstaining of teeth in people using iron supplements andiron factory workers is well documented (Nordbo et al.,1982). In a study conducted on school going students ofblack stain scraping was taken from 5 students and itwas subjected to analysis for trace elements. Traceelements analysis was done by (ICP) InductivelyCoupled Photo spectrometry. Out of 5 scrapings,3 showed presence of ferrous ions of about 2.56%,calcium ions 17.15% and magnesium ions 0.72%, whilethe remaining 2 samples showed calcium 14.86%,magnesium ions 0.82% and no presence of ferrous ions(Tirth et al., 2009). Copper causes a green stain inmouthrinses containing copper salts (Waerhag et al.,1984) and in workers in contact with the metal inindustries (Dayan et al., 1983) (Table 1).A number of other metals have associated colors suchas potassium permanganate producing a violet to blackcolor when used in mouth rinses; silver nitrate salt usedin dentistry causes a grey color, and stannous fluoridecauses a golden brown discoloration (Ellingsen et al.,1982). It was previously thought that the mechanism ofstain production was related to the production of thesulphide salt of the particular metal involved (Moranet al., 1991). This is perhaps not surprising since theextrinsic stain coincided with the color of the sulphide ofthe metal concerned. However, those proposing thehypothesis appeared not to consider the complexity ofthe chemical process necessary to produce a metalsulphide. As mentioned earlier the interest aroused bythe staining noted with use of chlorhexidine mouth rinsehas prompted renewed interest in the mechanism ofstain formation. For this reason most of the research intostain formation has been carried out on chlorhexidine,although there are other antiseptics which cause stainingto a lesser extent and the mechanism proposed could beapplicable to staining found with polyvalent metals. Thecharacteristic staining of the tongue and teeth noted byFlotra and co-workers in 1971 is not peculiar tochlorhexidine, it has been reported in other cationicantiseptics, the essential oil/phenolic mouth rinse‘Listerine’ and following prolonged use of delmopinolmouthrinses (Claydon et al., 1996). There is greatindividual variation in the degree of staining from personto person, this makes explanation more difficult as it maybe caused by intrinsic factors, differences in extrinsicfacto