By Ron Goodlin, DDS, FAGD; Holly Gilchchrist, CDA, Stage II and Lori Place, CDA, Stage II
The "teeth whitening" industry is a billion-dollar-a-year bonanza for companies that manufacture and market whitening products to the public and for dentists who are knowledgeable and willing to offer these services to their patients. The average person's desire to look better "now" and the fact that the public wants everything done with a quick fix is a fact of life in our modern, fast-paced society.
The popularity of tooth whitening is understandable, as it provides the patient with a quick, if not instantaneous, non-invasive and affordable result. The public is bombarded with articles about teeth whitening and advertisements in glamor and lifestyle magazines. The Internet is full of websites dedicated to teeth whitening. The stars they see and emulate in film and television, and the popularity of extreme makeover shows are testament to the public's heightened interest in cosmetic procedures. As dentists, it is important for us to understand the etiology of tooth discoloration so that we can properly advise our patients on which form of treatment is most suitable for their situation.
I) SCIENTIFIC FOUNDATION
Color and anatomy of normal teeth.
The reflection, absorption, translucency and opalescence of light create the color saturation and value of a tooth. The thickness of the enamel and the color of the underlying dentin are the determining factors for the color of the resulting tooth (Fig. 1).
Historically, measuring color changes after teeth whitening procedures has been highly subjective. Taken by the dentist, patient and/or dental assistant using one of several possible color guides, some of which are provided by the manufacturer as a printed tab on a sheet of Mylar to hold against the teeth. (How do we know that the color differences between these different color swatch systems are not narrower than those of other color swatch systems, so that six hue differences in one system can correspond to only three hue in another? )
Historically, hues were ordered by color group rather than increasing in value. Newer guides such as Vident's Vitapan 3D Master Shade Guide can give a more accurate indication of actual color ranges and are therefore more specific in measuring color changes. However, the issue of subjectivity persists, often leading to questionable claims of "ten shades of difference in one week!".
Computer Aided Color Measurement Devices (Shade Scanners) – (Shadescan, Vita Easyshade, Shadevision) Determining hue becomes a straightforward exercise. This allows the dentist to better determine the results of tooth whitening procedures using color scanning devices to obtain an empirical before and after measurement of tooth shade, chroma and value (Fig. 2).
Etiology of tooth discoloration
Tooth discoloration is caused by large pigmented organic molecules that reside on the surface of the tooth or are embedded in the enamel and/or dentin matrix.
The discoloration can be labeled according to the etiology of the discoloration and the associated depth and location of the discoloration.
1. Weird coloring:
a) Extrinsic surface staining: If the molecules on the tooth enamel surface are within the surface protein layer (pellicle), they can be removed by thorough mechanical cleaning of the tooth. This type of stain is usually caused by all types of tobacco, tea, coffee, red wine, berry, and plaque buildup.
b) Penetrated extrinsic staining: due to fissures and microscopic porosities in the enamel matrix, these molecules can penetrate the surface layer of the enamel itself. The resulting discoloration cannot be removed by mechanical means and must be chemically treated to remove pigmented molecules from the surface of the enamel matrix. There are occasions when drugs stain teeth, as in the case of patients undergoing chemotherapy (fig. 3).
2. Own coloring:
Intrinsic stains refer to those stains that are incorporated into the dentin or enamel matrix during the embryological development of these structures. These stains include tetracycline staining, fluorosis, and staining from systemic conditions such as high fever during tooth development.
Etiology of intrinsic tooth discoloration:
i) Drug-related discoloration: (tetracycline, monocycline)
Tetracycline molecules are actually incorporated into the enamel matrix by chelation of the tetracycline molecule with calcium, resulting in tetracycline orthophosphate. Discoloration occurs when this molecule reacts with sunlight and darkens with increased exposure to sunlight (Fig. 4).
ii) Discoloration due to mineralization: (fluorine, calcium)
Fluorosis occurs with prolonged ingestion of fluoride ions greater than 1-2 ppm. Ameloblasts are affected, resulting in defective calcification of the developing enamel matrix. Instead of enamel forming as a homogeneous mass, areas of hypomineralized and porous sublayers alternate with areas of hypermineralized enamel. The result is enamel hypoplasia in the form of brown and white streaks known as mottled enamel1 (Fig. 5).
iii) Systemic diseases: (Amelogenesis imperfecta, Dentinogenesis imperfecta) Discolorations due to systemic diseases can range from genetic problems (Amelogenesis imperfecta, Dentinogenesis imperfecta (Fig. 6), cleft lip and palate) to medical conditions such as high fever and periods of use of tooth development drugs. These can lead to hypoplasia, striae and mottled enamel (cerebral palsy, kidney disease, severe allergies, development of vitamin C, vitamin D, calcium and phosphorus deficiency, neurological disorders), discoloration (blue-green or brown due to bilirubin staining) . infantile jaundice, brown discoloration due to destruction of blood cells during erythroblastosis fetalis, and purplish-brown discoloration in patients suffering from porphyria).
Patients undergoing chemotherapy and taking high doses of strong drugs to treat illnesses become more prone to discoloration due to dry mouth and various drug reactions.
iv) Trauma: Traumatic injuries can also cause banding, enamel hypoplasia and calcified sites. This most commonly occurs when a child knocks out their primary anterior tooth, resulting in disruption of enamel matrix formation in the developing permanent tooth bud.
Dark gray teeth are the result of situations where a tooth has been traumatized, causing internal bleeding in the pulp chamber. As the blood cells migrate and settle in the dentinal tubules, they eventually break down, leaving behind iron molecules in the form of hemosiderin, which gives the tooth a gray tint. Many of these teeth may remain vital, while others may require endodontic therapy to treat the resulting pulpal necrosis (Fig. 7).
v) Dental diseases:
a) Tooth decay appears as a gray discoloration, white cloudiness, or brown or black discoloration due to decaying bacteria and food debris.
b) Amalgam can stain dentine and cast a shadow across thin enamel.
c) Old composite materials that were unstable in color may discolor over time, causing shadows on the overlying enamel (Fig. 8).
d) Metal posts also create internal shadows that result in a gray tint on the tooth.
vi) breakdown of the enamel matrix
a) The enamel matrix is constantly subjected to the effects of thermal expansion, which generates microporosities and cracks that allow pigment molecules to infiltrate the enamel matrix.
b) Acids open pores in enamel, as we know from our studies of acid etching and bonding, these micropores allow entry of pigmented molecules.
vii) aging process
a) Aging often leads to a yellowing of the teeth. As we age and the enamel on our teeth thins due to wear and tear, the deep yellow color of the underlying dentin and secondary dentin deposition on the tooth is reflected through the enamel, giving the appearance of a dull, yellow-looking tooth. older. Thinner paint is the opposite.
the enamel matrix is broken with lines of cracks in the enamel or real stained cracks in the tooth (Fig. 9).
b) Enamel cracks due to internal fractures of the enamel matrix and stain penetration of crack lines result in tan crack lines in aged teeth.
The chemical-biological mechanism of whitening
Teeth whitening or discoloration is achieved through the oxidation of organic particles due to the release of highly unstable free radicals (perhydroxyl ions) from activated hydrogen peroxide. Hydrogen peroxide can penetrate the inorganic salts and organic matrix of tooth enamel and penetrate the dentin layer. (This invasion may later cause tooth sensitivity diagnosed as mild to moderate reversible pulpitis in the form of tingling or cold sensitivity after whitening.2)
Bleaching can be done using carbamide peroxide or hydrogen peroxide. Carbamide peroxide, also known as urea peroxide, breaks down into water and hydrogen peroxide. The higher the concentration of hydrogen peroxide, the more free radicals are available for the bleaching process. A concentration of 10 percent carbamide peroxide corresponds to approximately three percent hydrogen peroxide.
Activation of hydrogen peroxide is accelerated by heat, which can come from body heat or exposure to high-intensity light. This results in a more efficient and rapid release of free radicals that penetrate the enamel matrix.3 Some studies suggest that there is no difference in the effectiveness of bleaching materials when used with or without photoactivation.4 Free radicals interact with large molecules of pigment from organic compounds within the enamel and dentin matrix. These large pigmented molecules break down and break down into much smaller, less pigmented molecules as they are chemically reduced by reacting with free radicals, thus reducing tooth pigmentation (Table 1).
Carbamide peroxide (CH4N2O2), also called urea peroxide: When mixed with water, urea and hydrogen peroxide are released (free radicals at about three percent concentration for a 10 percent carbamide peroxide gel) , which leads to oxidation of organic particles. 🇧🇷 Other gel ingredients may include glycerin, carbopol, sodium hydroxide, sodium benzoate, triethanolamine, artificial sweeteners, colors and flavors. The latest surfactant technology has added citric acid, EDTA and other chemicals to increase penetration into the enamel matrix, and photoactivators and chemicals to cause a higher concentration of free radicals to be released during activation.
Hydrogen peroxide is employed in concentrations ranging from 7.5% to 38% (7.5% hydrogen peroxide releases about 3% of oxidizing free radicals, as do carbamide peroxide materials when 10%) . Manufacturers have suggested that when used in conjunction with light or laser to enhance activation, it will speed up the bleaching process (7.5 percent light-activated H2O2 has been suggested to release five percent of oxidizing free radicals).
II) DIAGNOSIS AND TREATMENT OF DENTAL DISCOLORATION
Successful treatment of tooth discoloration depends on proper diagnosis and treatment planning for each patient. When bleaching is proven to be the best treatment, the effectiveness of the treatment depends on patient compliance, the condition of the teeth, the type of stain and the concentration, duration and application system of the bleaching agent used.
Diagnosis of teeth discoloration
History - to identify genetic and systemic diseases.
Dental history: to identify traumatic incidents and genetic conditions.
Oral hygiene plate, material alba, surface material discoloration.
Clinical condition - existing restorations - discoloration due to caries, existing restorations, posts.
Dental vitality - endodontic condition.
Transillumination - cracked enamel matrix.
Enamel condition and thickness.
teeth discoloration treatment
brushing your teeth (including those that contain baking soda)
Indications for mechanical treatment
a) Large accumulation of plaque.
b) Surface stains from tobacco, food coloring, surface agents.
Indications for chemical whitening:
a) Slightly or moderately discolored or darkened teeth.
b) The condition of the tooth is healthy.
c) The patient's clinical history is impeccable.
Contraindications of chemical whitening
b) Damaged tooth with open dentinal tubules.
c) abfractional lesions or cold-sensitive recessions.
d) Large pulps and teeth sensitive to cold.
e) Allergy to peroxide.
f) Patient with low adherence.
3. Physical and chemical combination
Whitening toothpastes (those containing hydrogen peroxide).
Microabrasion – Ultradent Opalustre (6.6% hydrochloric acid paste).
Indications for combined mechanical and chemical treatment
a) Slight discoloration of the surface can usually be treated with whitening toothpastes.
b) Calcified areas and stained enamel can often be treated with microabrasion.
4. Recovery Solutions
Veneers (both direct composite resin and indirect porcelain).
Composite restorations to replace old amalgams, cavities.
Indications for restorative treatment
a) Active caries.
b) discolored old restorations.
c) Internal discoloration due to restorative material, amalgam, nails.
d) Strong staining due to systemic or genetic conditions.
5. Combination of chemical and restorative treatment
Whitening for veneers.
Whitening of the prepared crown stump.
Internal whitening before restorative treatment.
Indications for combined chemical and restorative treatments
a) Discolored teeth to be veneered after whitening.
b) Discolored teeth before making the definitive crown.
c) Teeth darkened before composite resin restorations.
d) Internal bleaching before post-endodontic restoration.
Before starting any cosmetic treatment, it is important to understand the patient's expectations. All patients expect excellent results and all patients believe they are candidates for a whitening procedure. It is up to the physician to correctly diagnose the etiology of the discoloration and to educate the patient about the various treatment modalities and expected success rates.
It is imperative that the patient understands that proceeding with chemical bleaching techniques does not guarantee the degree of bleaching and the treatment will not lighten existing restorations. Equally important is explaining the procedure, potential risks, and the importance of patient compliance for successful treatment. As with any treatment, it is necessary to discuss all financial arrangements before starting treatment. The author recommends personally taking impressions to manufacture the whitening trays immediately to get the patient excited about the upcoming treatment, but not making these trays until the procedure is fully paid for.
III) TYPES OF BLEACHING SYSTEMS
Delivery Systems: There are four categories of over-the-counter products and three main categories of supervised dental products.
1. Over-the-counter (OTC) products
a) Whitening toothpaste - physical action with some whitening chemicals (sodium bicarbonate, sodium hydroxide, H2O2)
b) Whitening Strip - Chemical (6.5 percent hydrogen peroxide) applied with self-adhesive strip.
Advantages: convenience, relatively inexpensive.
Disadvantages: Takes a long time to achieve desired results, requires frequent follow-up treatments, and increases long-term costs.
c) Whitening gels - chemical products, usually carbamide peroxide.
i) Paint: carbamide peroxide or H2O2 mixed with thickeners and adhesives to help the material adhere to the tooth.
Pros: Relatively cheap, convenience.
Disadvantages: tastes bad, takes a long time to get results, requires frequent use.
d) At-home whitening tray systems.
Homemade Bowl Delivery: Carbamide peroxide gel in a plastic bowl that is generically made.
Pros: Relatively cheap, convenience. It is often purchased over the Internet.
Disadvantages: ill-fitting casings cause safety issues, take longer to obtain results (Table 2).
2. Dentist Monitors
a) In the office – chemistry.
i) Light/Laser Activated: Carbamide or Hydrogen Peroxide or a combination placed on the tooth surface and activated by UV. Light, halogen light, plasma or laser arc. Zoom (disc), lumalite.
Advantages – Very economical but immediate cosmetic procedure – Soft tissue protection available without rubber dam.
Cons: It's not legal in Canada for DDS time consuming teeth whitening aids. Tooth sensitivity, risk of gum irritation.
b) In-office whitening with trays - chemical product with high concentrations of hydrogen peroxide (35-38 percent) placed in a specially adapted tray.
Pros - Very fast results for sure. It is used to start a case within 30 minutes.
Cons: tingling, numbness, excessive salivation, sensitivity to heat and cold.
c) Trays of household chemical bleach, typically carbamide peroxide, placed in a specially adapted tray. (Available in strengths of 10 percent – 16 percent – 22 percent).
Pros - Inexpensive, great fast results, safe. Patient controls treatment - convenience factor, very little dentist time, assistants take impressions and mold.
Disadvantages - Tingling, numbness, excessive salivation, sensitivity to heat and cold, gum irritation if the patient uses a lot or the splints are poorly made. The patient must be informed about the application of the gel. Patient compliance is beyond the dentist's control (Table 3).
Methods and materials
In-office treatment: dentally controlled prophylaxis of the tooth surface with prophylactic paste, Cavi-Jet, mechanical scaling, air abrasion to remove surface discoloration.
At home: toothpastes used at home to remove plaque and surface stains.
In practice, in the treatment chair: Light- or laser-activated bleaching has been shown to achieve the greatest effect in the shortest possible time. Supervised DDS allows the use of higher concentrations of bleach that are safe for the patient.
Take-home whitening kits using professionally manufactured trays result in a safe whitening method with results that are generally the same as light-activated systems; However, it may take several longer treatments to achieve the same result. Over-the-counter home bleaching is questionable for deeper intrinsic stains, but works well for superficial extrinsic stains with a combination of mechanical and chemical bleaching given enough time and patient compliance.
OTC products have questionable delivery systems, the active bleach may not reach the enamel matrix area in the concentrations needed to actively cause organic molecular oxidation. This reduced effectiveness due to reduced chemical concentration and often questionable delivery systems leads to a situation where repeated applications are required before results are visible, dramatically increasing the time required for treatment. Due to this less efficient delivery system, there is a much greater risk of material choking, gum irritation and reduced effectiveness. The biggest problem is patient compliance. After a few treatments, the rest of the material usually sits in a drawer until the patient decides to try again months later, and now the material has expired. The patient then complains that it didn't work!
Discuss bleaching procedures.
Examine the patient to determine the nature of the discoloration and the appropriate treatment procedure, whether it be a veneer precursor or a stand-alone procedure, etc.
Ask the patient about their expectations.
Explain that existing restorations will not lighten and will need to be replaced after the procedure.
Explain that there is no guarantee that whitening will work. 10% with no significant effect, 60% with a difference of 2 to 5 tones, 20% with more than 5 tones of difference.
Discuss expected time and number of procedures.
Discuss the costs involved.
Discuss the difference in technique between vital and non-vital (endodontically treated) teeth.
Explain the risks, possible tooth sensitivity, gum irritation.
Please explain what you believe to be a reasonable expectation from this procedure.
Teeth whitening vital power in practice
Complete dental prophylaxis.
Pre-shading and photography.
Isolate teeth with a rubber dam or gum shield as directed.
Orabase or gum protector to protect the papillae.
Prepare electrical bleach according to the manufacturer's instructions.
Apply the whitening gel according to the manufacturer's instructions.
Active light or laser gel depending on material choice.
After the specified bleaching time, aspirate and reapply the fresh gel.
Upon completion of the procedure, carefully wash all material from the teeth.
Remove gum guard/rubber dam.
Follow the shadows and take pictures.
When treating previously endodontically treated teeth with internal staining, the older method of heat-treated hydrogen peroxide (cervical root resorption is a possible consequence of internal bleaching and is more commonly seen in teeth treated with the thermocatalytic process) in combination with a "Walking Bleach". , it releases oxygen, which acts to oxidize the internal organic materials that are causing the discoloration. A combination of 30% hydrogen peroxide mixed with sodium perborate is left on the tooth as a tetrahydrate for one week. The patient returns for repeated treatments until the desired results are achieved. (Ho and Goerig 1989, Anitua et al. 1990, Baratieri et al. 1995, Walton and Rotstein 1996) Calcium hydroxide is placed for seven days to counteract any effects and prevent any cervical erosion. Under this protocol, an overall success rate of 80 percent has been reported. (This includes a 92% success rate for ideal cases over a 5 year period and a 55% success rate for poor clinical conditions over a 5 year period.6) The Walking Beach technique is now the treatment of choose when Seal is administered correctly. created first.
Powerful in-office whitener for devitalized teeth
Evaluate the endodontic situation clinically and radiologically.
Complete dental prophylaxis.
Record and photograph the color of the temporary tooth.
Put rubber dam and gum protection.
Open the lingual approach and remove excess gutta-percha to 1 mm below the gingival margin (use a #2 round bur in a low-speed handpiece).
Carefully remove the inner surface layer of dentin to reveal a fresh surface and try to remove the discolored dentin material.
Seal the gutta-percha with ionomer composite resin or hybrid composite.
The pulp chamber and the entire buccal and lingual area are now covered with whitening gel.
Light cure the labial and lingual activation according to the manufacturer's instructions for a total of 30 minutes, aspirate and apply fresh gel if necessary.
Upon completion of the procedure, carefully wash all material from the teeth.
Assess whether the tooth needs additional whitening. If that's the case, make a walking bleach by putting a mixture of Amosan (sodium perborate) and whitening gel and packing it into the chamber. Seal the tooth with caries. The patient should be reordered for a reassessment within three days.
Restore the access opening with a clear dentin-colored composite to achieve the desired final tooth shade.
Remove gum guard/rubber dam.
Follow the shadows and take pictures.
whitening at home
Complete dental prophylaxis
Record and photograph the color of the temporary tooth.
Make an impression of the dental arch to be bleached. Check the quality!
Production of individual whitening trays:
Prepare casts to remove the vestibule and palate.
Cut so that the base of the model is thinner than the occlusal plane (this helps to obtain a more accurate image).
and sealing around teeth during vacuum forming) (Fig. 10).
Make sure all bubbles are full, bubbles are removed.
Gently open the gingival margins to improve the seal of the whitening tray to the gingival margins (Fig. 11).
Take a small amount (0.5 mm) of the blocking resin and place it on the buccal parts of the teeth to create a small deposit in the whitening tray. Make sure it is not less than 1mm from the gingival margin as this will interfere with the marginal fit. Light cure each tooth.
Lubricate the model with PAM.
Preheat the shell forming machine with the plastic film on top, place the model in the vacuum mold and make the shell with a thin and smooth plastic film. (Hold the rocky surface towards the model) Once the plastic sheet is sunk in about 1 inch, turn on the vacuum and slowly lower the hot tray material onto the model (Fig. 12).
After the tray has cooled, remove the plastic from the stone model (Fig. 13).
Using sharp scissors, cut the plaque 2 mm from the gingival margin of the teeth.
Carefully cut to within 1/4 mm of the gingival margins with sharp precision scissors (Fig. 14).
Using a small butane torch, lightly crumble the edges of the bowl to gently melt the edges to round them off and remove any rough edges (Fig. 15).
Wash, disinfect the tray and place it in a labeled container for delivery to the patient.
1. Distribute the whitening tray, try it on and make sure it fits perfectly but is comfortable.
2. Patient instructions must be given verbally and in writing. Patients can clear for 2-4 hours while sleeping or during the day.
Check the patient after 7 days to check the fabric and whitening effect. This is a good opportunity to discuss any patient concerns. If the patient has persistent tooth sensitivity, topical application of fluoride is recommended.
3. Combination of mechanics and chemistry.
Microabrasion with a paste of abrasive and bleach chemicals applied to the tooth enamel surface using a prophylaxis cup.
Isolation of teeth with rubber dam, ligation and tissue protection with light-cured Gingiva Seal (Ultradent)
Careful application of abrasive micropaste with a prophylaxis cup
Apply fresh material if necessary.
Watch if the patient reports that the tooth is getting sensitive and stop the procedure.
Brush your teeth and apply fluoride treatment.
Patient discharged, new consultation in a week to continue the treatment until the desired result is obtained (Figs. 16 and 17).
4. Recovery Procedure.
Aesthetic restorative techniques such as direct and indirect crowns and veneers are used to cover decayed and severely discolored teeth when whitening techniques are unlikely to work or when previously tried whitening techniques have not produced the desired results (Figs. 18 and 19).
5. Combined Restoration and Bleaching Techniques In situations where teeth require restoration and are discolored, bleaching techniques can be used prior to restoration to improve the underlying color and obtain an excellent cosmetic result. This can also be used on non-vital teeth to whiten the underlying tooth structure prior to crown placement.
EFFICIENCY OF DIFFERENT DELIVERY SYSTEMS
Overall, 20% are expected to achieve a change of 5 or more tones, 53% to achieve a change of 2 to 5 tones, and 27% to achieve a change of less than 2 tones. 7 These figures are based on older formulations. With advances in surfactant technology, we expect these numbers to change significantly to: 5% less than 2 tones, 35% 2-5 tones, 40% 5-7 tones, and 20% 8 tones or more.
The active ingredient in all bleaches is hydrogen peroxide. This H2O2 can be applied in the form of carbamide peroxide or hydrogen peroxide and can be mixed with many different surfactants, such as H2O2 in the enamel and dentin matrix, as well as various acids. Additional products include the addition of potassium nitrate to reduce the post-operative sensitivity that patients often experience after treatment. As surfactant technology becomes more advanced, the bleaching process becomes faster and more efficient, resulting in more pronounced shade changes. Zoom appears to have the best surfactant technology at the time of writing.
Instant activation by mixing materials at the time of use provides more efficient free radical release and longer shelf life. Premixed materials rely solely on heat activation to release free radicals, but this works slowly and inefficiently, and they show reduced effectiveness once they reach their shelf life limits.
Activation by light or laser
With the proper formulation of surfactants, a more efficient release of oxidizing free radicals can be achieved, making the bleaching process more efficient in less time. At the time of writing, the Discus Dental Products Zoom, using an intense application of ultraviolet light, appears to produce the most dramatic effects in the shortest possible time.
Issues related to reports in the literature:
Technology is changing so rapidly that by the time many articles are published, new products and, in particular, improvements in surfactant technology are making the products and techniques discussed obsolete. It is expected that new formulations and delivery methods will put the reported results in a more positive light, allowing us to achieve better results than those previously reported in the literature in a shorter time. We found that the results with the Zoom system were much better than any other material tested to date.
Reported cases, particularly at-home bleaching systems, indicate results that are impossible to fully or objectively monitor and are based on assumptions of 100% patient compliance, proper use of materials, and zero bias in determining color selection.
SAFETY IMPLICATIONS AND CONCERNS
Li reports the carcinogenicity and genotoxicity of peroxides when used as bleaches. Reports indicate that hydrogen peroxide is a promoter of carcinogenicity in the presence of cigarette smoke. Therefore, it is important that the patient does not smoke during the bleaching process and for a reasonable time afterwards.8
Some studies have shown dissolution of the enamel layer with the use of over-the-counter acidic products over a prolonged period.9 Other studies have shown a reduction in microhardness in the enamel matrix after prolonged bleaching.10 It appears that when it is properly controlled, this is not clinically significant. but this again indicates that adequate dental supervision is necessary for the ultimate safety of the patient.
Tissue irritation after bleaching is generally limited to mild irritation and hyperemia, but there are reports of severe bleaching when the bleaching material is in contact with the tissue for a long time, which can lead to gingival detachment and painful tissue areas. This again points to the need for proper dental supervision and careful fabrication of custom trays to create a seal that prevents excess material from coming into contact with the gingival tissue. This is preferable to storage trays available on OTC products that can be hazardous to the patient.11
There is no statistically significant difference in posterior plaque accumulation after tooth bleaching procedures.12
Free radicals from oxidation can penetrate the enamel matrix and induce sensitivity due to stimulation of exposed dentinal tubules.
Large pulps: Younger patients do not appear to create a situation where the sensitivity experienced is a disadvantage for treatment.13
F POST-OPERATIVE SENSITIVITY
Application of topical fluorides immediately after treatment appears to provide the greatest relief from tingling and cold sensitivity. Recent formulations of some whitening products contain potassium nitrate, a molecule commonly used in anti-sensitivity toothpastes that is said to seal open dentinal tubules, reducing sensitivity.
dr. Goodlin has a cosmetic dentistry practice in Aurora ON. He is a well-known speaker and author of numerous publications on cosmetic dentistry and dental photography.
Oral Health appreciates this original article. Part II in May 2004 with full references.