What causes white spots on teeth?
The phenomenon of white spots on teeth can have a variety of causes. These include trauma to a tooth during its formation, exposure to excessive amounts of fluoride while the teeth are developing (called fluorosis), developmental disorders, and tooth decay. Each of those conditions present their own unique challenges in terms of getting rid of these unsightly discolorations. For the purposes of this post I will focus on the latter cause: tooth decay.
White (or brown) spot lesions are areas where a cavity is beginning or did start at one time but has stopped and the white spot remains as a ‘scar’ in the tooth. The root cause of tooth decay is bacterial plaque (the film that forms around teeth when not properly brushed or professionally cleaned on a regular basis). When we eat carbohydrates, bacteria in our mouths feed on the carbohydrates and produce acid as a byproduct. This acid pulls minerals out of our teeth. The acid generally comes in contact with the enamel of our teeth first. The enamel is the outer layer of the teeth, which is a hard crystalline substance that is the hardest substance in our bodies. Enamel is naturally translucent (partially see-through) almost like tinted glass. If bacterial plaque remains on the tooth undisturbed for 14 days, a white spot lesion can form1. When acid from bacteria attacks the enamel, this damages the crystals and can leave voids in the enamel. These voids/defects in the enamel change the way that light passes through the enamel, which make them appear opaque white (not see-through) in contrast to the pearlescent appearance of regular enamel. Over time, pigments from food/drink can be taken up into these voids and can turn the white spots brown. Once a white spot forms, these are two ways it can go depending on if oral hygiene improves or not. If the areas are cleaned and plaque is regularly removed from the white spot, it can stop growing. If the white spots remain under attack from acid, the white spot’s surface can start to chip away and become a true “cavity” that will have to be treated with a filling. White spots commonly form by the gum line of a tooth (where plaque is prone to collect) and around orthodontic brackets while someone has braces, as these areas are hard to clean. Even if they do stop growing and do not technically need to be “filled”, many people seek cosmetic solutions for these areas as they can be unaesthetic.
What can you do about them?
There are several options for treating these white spot lesions. These include veneers – which are made either out of porcelain or composite resin and cover the entire front surface of the tooth – and resin fillings in which only the discolored area is removed and replaced with composite resin. These options generally require the patient to be numbed and tooth structure to be removed, which can be stressful and uncomfortable to the patient. More conservative methods include fluoride therapy in which fluoride paste is applied to the tooth with the hope that fluoride can be taken up into the white spots and make them less visible. This can be done at home and in a dentist office where a dentist can clean and dry the teeth and place the fluoride on the teeth for multiple sessions. This can de bone in conjunction with teeth whitening to make the teeth around the white spots lighter, therefore making them less visible. However, this approach takes multiple appointments spread over weeks or months. Also, professional whitening can cause hot/cold sensitivity and it is generally avoided in young patients due to the risk of extreme sensitivity.
Another approach that is relatively new for the treatment of white spots is resin infiltration. With this treatment method, the teeth to be treated are cleaned and dried thoroughly, and a clear resin (a chemical very similar to those used in bonding tooth colored fillings to teeth) is placed on the teeth and allowed to flow into the voids of the white spots. The resin is then light-cured and polished. This process has been shown to make the white spots less prone to further decay.2 The ability for resin infiltration to mask white spot lesions has been shown in laboratory research3 and in case reports.4 The images at the top of the post and below are examples of results I have obtained on my own patients.
How often does resin infiltration work?
Every patient is different, and every situation is different. Hence resin infiltration will not work on all cases of white spots. White or brown spots that are due to trauma (meaning they are more likely to be very deep in the tooth) are more difficult to remove and may require a filling or veneer to effectively remove. White spots on teeth from decay are generally more superficial (shallow) and easier to fix with more conservative means. Also, one must keep in mind that both healthy tooth structure and tooth colored fillings can stain over time. This holds true for the resin used in resin infiltration, as it has been shown to be prone to discoloration in a laboratory setting.5 Since resin infiltration is a fairly new treatment modality, more time and more studies will be needed to see how color stable the resin is over time. However, even if the resin does discolor over time and will need to be replaced with bonding or veneers, delaying this more aggressive treatment is a good thing for a younger patient. The earlier in life someone has a tooth drilled on, the more likely that they may have sensitivity or damage to the nerve of a tooth. Nerves of teeth get smaller as teeth get older, therefore making sensitivity and nerve damage less of a concern with age.
Resin infiltration is a relatively new, conservative approach to treating white spot lesions that can be done in one visit with no numbing agent and no drilling into tooth structure. This an exciting treatment option that I have been offering in my practice in Birmingham, Alabama for the past year. If you think this may be of interest to you, please call the office at (205) 250-6813 to learn more.
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1. Fejerskov O, Kidd E. Dental Caries: The Disease and its Clinical Management, Second Edition. Oxford: Blackwell Munksgaard, 2008. Print.
2. Paris S, Schwendicke F, Seddig S, Müller WD, Dorfer C, Meyer-Lueckel H. Micro-hardness and mineral loss of enamel lesions after infiltration with various resins: Influence of infiltrant composition and application frequency in vitro. J Dent. 2013 Jun;41(6):543-8. DOI: 10.1016/j.jdent.2013.03.006. Epub 2013 Apr 6. PubMed PMID 23571098.
3. Paris S, Schwendicke F, Seddig S, Müller WD, Dorfer C, Meyer-Lueckel H. Masking of white spot lesions by resin infiltration in vitro. J Dent. 2013 Nov;41 Suppl 5:e28-34. DOI: 10.1016/j.jdent.2013.04.003. Epub 2013 Apr 11. PubMed PMID 23583919.
4. Shivanna V, Shivakumar B. Novel treatment of white spot lesions: A report of two cases. J Conserv Dent. 2011 Oct;14(4):423-6. DOI: 10.4103/0972-0707.87217. PubMed PMID 22144817.
5. Borges A, Caneppele T, Luz M, Pucci C, Torres C. Color Stability for Caries Infiltration After Exposure to Different Staining Solutions. Oper Dent. 2014 Jul-Aug;39(4):433-40. DOI: 10.2341/13-150-L. PubMed PMID 24967985.