Extrinsic stains are defined as stains located on the outer surface of the tooth structure and caused by topical or extrinsic agents.
Extrinsic dental stains are caused by predisposing factors and other factors such as dental plaque and calculus, foods and beverages, tobacco, chromogenic bacteria, metallic compounds, and topical medications.
Certain factors predispose children and adults to extrinsic stains, include enamel defects, salivary dysfunction, and poor oral hygiene.
Microscopic pits, fissures, and defects in the outer surface of the enamel are susceptible to the accumulation of stain-producing food, beverages, tobacco, and other topical agents.
As saliva plays a major role in the physical removal of food debris and dental plaque from the outer and interproximal tooth surfaces, diminished salivary output contributes to extrinsic discoloration. Decrease in saliva may be caused due to any disease.
The most common cause of extrinsic stains is poor oral hygiene.
Accumulations of dental plaque, calculus, and food particles cause brown or black stains .
Deposition of tannins found in tea, coffee, and other beverages cause brown stains .
Tobacco stains from cigarettes, cigars, pipes, and chewing tobacco cause dark brown and black stains that cover the cervical one third to one half of the tooth.
Pan chewing results in a red-black stain on the teeth, gingiva, and oral mucosal surfaces.
Metallic compounds are also implicated in dental discolorations because of the interaction of the metals with dental plaque to produce surface stains. Industrial exposure to iron, manganese, and silver may stain the teeth black. Mercury and lead dust can cause a blue-green stain.
Chromogenic bacteria cause stains, typically at the gingival margin of the tooth. The most common is a black stain caused by Actinomyces species. The stain is composed of ferric sulfide and is formed by the reaction between hydrogen sulfide produced by bacterial action and iron in the saliva and gingival exudates. Green stains are attributed to fluorescent bacteria and fungi such as Penicillium and Aspergillus species. Orange stain is less common than green or brown stains and is caused by chromogenic bacteria such as Flavobacterium lutescens .
Topical medications cause staining. Such as Chlorhexidine rinse causes brown staining after several weeks of use, particularly on acrylic and porcelain restorations. Iron-containing oral solutions used for treatment of iron deficiency anaemia cause black stains. Potassium permanganate mouthwash (violet-black stain), silver nitrate (black stain), and stannous fluoride (brown stain) also can induce dental discolorations. Some systemic medications (e.g. minocycline, doxycycline) can also cause extrinsic staining.
Red extrinsic stain at gingival margin and interproximal and incisal region-habit of chewing pan.
Intrinsic dental stains are caused by certain dental materials, dental conditions like caries, trauma, infections, medications, nutritional deficiencies, genetic defects and hereditary diseases (e.g. those affecting enamel and dentin development or maturation).
Dental restorations most commonly cause intrinsic discoloration. Amalgam restorations can generate corrosion products leaving a gray-black colour in the tooth, especially in large cavity preparations with undermined enamel.
Composites, and glass ionomer and acrylic restorations gradually can leave a gray hue in the tooth adjacent to the material.
Other dental materials that cause intrinsic discoloration include eugenol, root canal sealers, and polyantimicrobial pastes.
The erosion of enamel caused by frequent ingestion of acidic foods and beverages and from the regurgitation of acid from the stomach can lead to a yellow tooth discoloration. In patients with anorexia, a yellow discoloration develops on lingual tooth surfaces where the acid reflux material makes contact with the teeth.
Patients with orthodontic brackets are at great risk for caries because of suboptimal plaque removal. As caries progresses into the dentin, the overlying translucent enamel reveals the color of the underlying caries and appears yellowish brown. Extensive caries that involve destruction of both enamel and dentin produce a color that ranges from light brown, to dark brown or almost black
The brown colour is attributed to the formation of Maillard pigments (reaction between proteins and small aldehydes produced by cariogenic bacteria), melanin, lipofuscins, and uptake of various food colours and bacterial pigments. 7 In some patients, the caries process can self-arrest, and remineralisation may occur; however, the brown discolorations usually remain.
Trauma to developing/yet unerupted, teeth can disturb enamel formation and may result in enamel hypoplasia, which is visualized as a localized opacity on the erupted tooth. Unerupted permanent incisors commonly are affected after intrusion injuries to primary incisors in young children who fall on their faces.
Trauma that occurs to erupted teeth also causes discoloration. This discoloration frequently occurs in teeth that have fully formed roots and have sustained irreversible pulpal injury caused by avulsions, intrusions, or fractures involving the pulp chamber. Trauma can cause intrapulpal hemorrhagic and iron sulfide deposition along the dentinal tubules, producing a bluish black cast.
Intrinsic dental discoloration caused by trauma to the mandibular incisors that led to pulpal necrosis.
Periapical odontogenic infections of the primary teeth can disrupt normal amelogenesis of the underlying permanent successors and involve a potential for localized enamel hypoplasia.
Rarely maternal rubella or cytomegalovirus infection and toxaemia of pregnancy can lead to tooth discoloration.
Crown formation of the secondary dentition occurs until the child is aged approximately 8 years. Systemic postnatal infections (e.g. measles, chicken pox, streptococcal infections, scarlet fever) can also cause enamel hypoplasia. The band like discolorations on the tooth are visualized where the enamel layer has variable thickness and becomes extrinsically stained after tooth eruption.
Tetracyclines diffuse through dentin to the enamel interface, chelating calcium ions and incorporating into hydroxyapatite as a stable orthophosphate complex. The amount of drug incorporation is determined by the distribution of tooth discoloration and is equivalent to serum blood levels and the duration of exposure. When the affected teeth first erupt, they have a bright-yellow band like appearance that fluoresces under ultraviolet light, although upon exposure to sunlight, the color gradually changes to gray or
Minocycline is a second-generation derivative of tetracycline. The ingestion of minocycline can lead to a green-gray or blue-gray intrinsic staining of teeth. Staining occurs during and after the complete formation and eruption. Minocycline was prescribed for long-term acne therapy in adolescents and adults, although it is being replaced by other medications.
Doxycycline has recently been reported to cause extrinsic staining of teeth, possibly by binding to glycoproteins in the dental pellicle in patients with poor oral hygiene in whom oxidation occurs.
Dental fluorosis is characterized by enamel discoloration resulting from subsurface hypomineralization due to the excessive ingestion of fluoride during the early maturation stage of enamel formation. Fluorosis affects primary and secondary dentitions
Tetracycline staining of mandibular teeth caused by the ingestion of tetracycline when the patient was aged 3 years.
Genetic defects in enamel or dentin formation include amelogenesis imperfecta , dentinogenesis imperfecta , and dentinal dysplasia . These are hereditary diseases with a propensity for intrinsic tooth discoloration.
Amelogenesis imperfecta affects both primary and secondary dentitions
Dentinal Dysplasia occurs in 2 types. Teeth with type 2 DD have a blue, amber, or brown translucence.
Other hereditary diseases include erythropoietic porphyria and epidermolysis bullosa (EB). Erythropoietic porphyria is a rare disease of porphyrin metabolism.
Discoloration include brown, black, gray, green, orange, and yellow. The scratch test is usually used to distinguish between extrinsic and intrinsic discoloration.
Discoloration colours include brown, black, gray, green, orange, and yellow. Unlike extrinsic discoloration, teeth with intrinsic discoloration may be red or pink. Under ultraviolet light, teeth with tetracycline staining and congenital porphyria may fluoresce yellow or red, respectively. Intrinsic discoloration cannot be removed by using the scratch test.
Dental treatment of tooth discoloration involves identifying the etiology and implementing therapy.
Diet and habits: Extrinsic staining caused by foods, beverages, or habits (eg, smoking, chewing tobacco) is treated with a thorough dental prophylaxis and cessation of dietary or other contributory habits to prevent further staining.
Tooth brushing: Effective tooth brushing twice a day with a dentifrice helps to prevent extrinsic staining.
Professional tooth cleaning: Some extrinsic stains may be removed with ultrasonic cleaning, rotary polishing with an abrasive prophylactic paste, or air-jet polishing with an abrasive powder. However, these modalities can lead to enamel removal; therefore, their repeated use is undesirable.
Bleaching (tooth whitening): Early bleaching techniques were developed almost a century ago, and all of the techniques involved a process of oxidation. Today, with proper patient selection, bleaching is a safe, easy, and inexpensive modality that is used to treat many types of tooth discoloration. Usually, bleaching is not indicated for the treatment of discoloration of the primary teeth. Bleaching includes 2 types of techniques: vital and non vital.
Bleaching of vital teeth is indicated primarily for patients with generalized yellow, orange, or light brown extrinsic discoloration (including chlorhexidine staining), it may be helpful in mild cases of tetracycline-induced intrinsic discoloration and fluorosis.
Nonvital bleaching is indicated for the treatment of teeth with discoloration secondary to pulpal degeneration. This technique involves placing a mixture of 30% hydrogen peroxide and sodium perborate into the pulp chamber for as long as 1 week.
Recommend all patients to perform daily oral hygiene by using a toothbrush, a dentifrice containing, and use dental floss.
Individuals who wear dentures should brush the prostheses after each meal to keep the prostheses free of plaque, calculus, and stains. Partial and complete removable prostheses (dentures) should always be removed during sleeping hours.