Teeth Whitening

Introduction

Tooth whitening is done to correct the discoloration of a tooth. When we talk about discoloration of a tooth, we mean to say that the colour of a tooth has become from its normal white colour to light, light brown to dark brown or from light Gray to dark Gray or to complete black. The discoloration may be of one tooth, or all the teeth may be discoloured. Discoloration of a tooth is caused by several factors. It may be due to deposition of external stains over the surfaces of a tooth, or it may be because of the internal position of certain chemicals into the teeth structure at molecular level during the period when teeth were being formed in the mother’s womb.

External Discoloration of the Teeth

External stains deposited on the surface of the teeth may be due to smoking, drinking tea or coffee or food colorants like turmeric. Poor oral hygiene habits may also lead to the external discoloration of teeth. 

Internal Discoloration of Vital Tooth

Tetracycline, excessive fluoride or other medication intake by a pregnant mother during developmental phase of the teeth of the foetus may result in the discoloration of the teeth as a child.

The Internal Discoloration of a Non-Vital Tooth

The discoloration of non-vital teeth is caused by the death of the pulp tissue due to trauma. In such cases, the pulp of the traumatized tooth goes through the death process and becomes necrotic. The necrosis or rotting of the pulp tissues produces Sulphur compounds that give the light brown to dark grey color of that particular tooth.

Procedure of Teeth Whitening

The procedure for teeth whitening depends on whether the tooth is vital or non-vital. These procedures should be performed by a qualified dentist. For common people, teeth whitening kits are available in the market. They can be utilized by anyone with care. The chemicals used for tooth whitening may be hydrogen peroxide or carbamide peroxide.

Technique of tooth whitening for non-vital teeth 

• It'll be a good idea to wait for at least 2 weeks after the completion of root canal treatment before the start of the tooth whitening procedure. During this time period we should watch for the development of any symptom. If no symptoms arise, then we should proceed for the tooth whitening procedure.

• Colour of the tooth should be matched with the shade guide, and it is recorded in the patient’s file.

• A successful root canal treatment of the dead tooth should be done.  Then only, a tooth whitening procedure should be performed to correct the discoloration of the tooth involved.

• The temporary filling material used to fill the access cavity after the root canal obturation should be removed up to 3 millimeters beyond the cervical line.

• Then, the remaining root canal filling material is covered by a setting calcium hydroxide paste of 1 millimeter thickness. The walls of the access cavity should be smoothed with the help of a dental bur. During the smoothening procedure, a smear layer develops over the smooth surface of the cavity. 

• This smear layer should be removed from the walls of the access cavity. This is necessary otherwise the opening of the dentinal tubules will remain blocked, and the tooth whitening chemical will not give its full effect. To do this, 37% orthophosphoric acid is applied over the surface of the access cavity and left for 20 seconds. It is rinsed thoroughly with water and air dried.

• A cotton pledged, soaked in hydrogen peroxide or carbamide peroxide is placed inside the access cavity and sealed by a temporary filling material, e.g. zinc oxide eugenol cement.

• It is left there for 2-3 or more days and continuously observed. The patient is instructed to report back when the colour of the tooth becomes slightly lighter than the neighbouring tooth, the cotton pledge is removed from the access cavity and a suitable filling is done.

Teeth whitening of the vital teeth

Sometimes, few of us, especially younger ones, think that the colour of their teeth is yellow or Gray, not the white. These days, beauty conscious people seek the help of teeth whitening procedures to lighten the teeth colour and make it look whiter. This is done by “Vital Teeth Whitening Procedure”. 

Technique of Vital Teeth Whitening 

• The original shade of the tooth is noted in the file.

• The shade guide is shown to the patient and the desired shade is also noted.

• A thorough scaling and polishing is done.

• All over the face, petroleum jelly is applied for protection from spill of etchant.

• Soft tissues are protected by protecting gel which is supplied by the manufacturer.

• The whitening agents are mixed as per manufacturer’s instructions and applied over the labial surfaces of anterior teeth, from canine to canine or from premolar to premolar.

• A light source is placed over it to enhance the chemical reaction.

• It is left there for the time period specified by the manufacturer.

• The whitening gel is washed away after the specified time.

• The colour of the teeth are matched with the help of a shade guide.

• If needed, the procedure is repeated again and again till the desired colour is achieved.

As a last step, the teeth, after washing away the whitening gal, are coated with a fluoride containing varnish.

The patient is instructed to not eat or drink anything, especially the carbonated drinks for one hour. This period is necessary for remineralization of the enamel by calcium present in the saliva.

Before a patient leaves the dental office, (s)he is advised to avoid eating or drinking foods that may speed up the discoloration of the teeth.

A lot of home kits are available for teeth whitening in the market. They can be used at home by anyone with little care. They are useful for mild to moderate discoloration of teeth.

Image source: Smile Dental (https://www.smilingdental.com.au/)

Fluoride as Anti-Caries

Clinical context

Water fluoridation is a safe, effective and ethical way to help reduce tooth decay across the population and has long standing support of peak public health and dental authorities.

Water fluoridation

Water fluoridation is a proven method for reducing the prevalence of tooth decay in communities.

Surveys of tooth decay and dental fluorosis must be undertaken regularly, taking into account all fluoride sources and patterns of consumption in a community, in order to confirm the most appropriate water fluoridation concentration for that community or region.

The optimal fluoride concentration of community water supplies will normally be in the range of 0.6 to 1 milligram per litre (mg/Litre) of water (commonly known as parts per million or ppm).

The fluoride content of bottled water should be clearly stated on the label.

Fluoride supplements

Fluoride drops or tablets should only be taken (swallowed) under the direction of a dentist.

Fluoridated toothpaste

From the time that teeth first erupt (about six months of age) to the age of 17 months, children’s teeth should be cleaned by a responsible adult, but not with toothpaste unless the tooth decay risk is deemed to be high, as assessed by a dentist.

For children aged 18 months to five years (inclusive), the teeth should be cleaned twice a day with toothpaste containing 0.5–0.55 mg/g of fluoride (500–550 ppm). Toothpaste should always be used under supervision of a responsible adult. A small pea-sized amount should be applied to a child-sized soft toothbrush and children should spit out, not swallow, and not rinse. Young children should not be permitted to lick or eat toothpaste. If risk of tooth decay is increased, concentrations of fluoride greater than 550 ppm may be used as recommended by a dentist.

For people aged six years or more, the teeth must be cleaned twice a day or more frequently with standard fluoride toothpaste containing 1 - 1.5 mg/g fluoride (1000–1500 ppm). People aged six years or more should spit out, not swallow, and not rinse. Standard toothpaste is not recommended for children under six years of age unless on the advice of a dentist.

For children who do not consume fluoridated water or who are at elevated risk of developing tooth decay for any other reason, guidelines about toothpaste usage must be varied, as needed, based on dental professional advice. Variations could include more frequent use of fluoridated toothpaste, commencement of toothpaste use at a younger age, or earlier commencement of use of standard toothpaste containing 1mg/g fluoride (1000ppm). This guideline may apply particularly to preschool children at high risk of tooth decay.

For teenagers, adults and older adults who are at elevated risk of developing tooth decay, dental professional advice should be sought to determine if they should use toothpaste containing a higher concentration of fluoride (i.e. greater than 1000- 1500 ppm up to 5000 ppm of fluoride).

Manufacturers must avoid flavours that imitate too closely popular food tastes to avoid accidental ingestion of large amounts of paste by very young children.

Application of topical fluoride

Concentrated forms of fluoride should only be routinely applied by suitably qualified dental practitioners and should only be used after taking into account an assessment of an individual’s tooth decay risk conducted by a dentist.

Fluoride varnish should be used for people who have elevated risk of tooth decay.

High concentration fluoride gels and foams (those containing more than 1.5 mg/g fluoride ion) may be used for patients who have an increased risk of tooth decay.

Fluoride mouth rinses

Fluoride mouth rinses must not be used by children under the age of six years due to the possibility that they will ingest some of the product and increase their risk of dental fluorosis.

Fluoride mouth rinses may be used by people over the age of six years under the direction of a dentist where it is considered an appropriate choice for preventing tooth decay in high risk individuals and where there is certainty that the individual will understand that the product should be rinsed as directed and spat out, not swallowed.

Fluoride, diet and cleaning routines

The beneficial effects of fluorides must be understood in conjunction with all the major risk factors for tooth decay.

A person’s inappropriate dietary and other habits have the potential to overcome the beneficial effect of fluoride, with poor oral hygiene habits, and high frequency or prolonged exposure to dietary sugars and acidic foods and beverages, posing the highest risk.

Scenario Based Question

Scenario: Sarah is a 7-year-old healthy girl who lives in an area in Australia where potable water contains 0.3 ppm fluoride. Her parents are concerned about her dental health and are wondering if she needs any additional sources of fluoride.

Question: What is the recommended daily fluoride intake for a 7-year-old healthy girl who lives in an area in Australia where potable water contains 0.3 fluoride?

a) No additional sources of fluoride are needed

b) 0.25 mg

c) 0.5 mg

d) 1 mg

Correct answer: b) 0.25 mg

This question is testing the knowledge of the recommended daily fluoride intake for a 7-year-old healthy girl who lives in an area in Australia where potable water contains 0.3 to 0.5 ppm fluoride, based on the Australian Dental Association guidelines.

Introduction to Third Molar Surgery: Part 3-Classification of Impaction

Classification of third molar impaction is done to facilitate the communication between clinicians, for record keeping that may be used for audit research purposes.    

Introduction to Third Molar Surgery-Part 1

The third molars are the most common teeth that are found to be impacted. This article will provide and introduction to this topic. The difference between simple and surgical extraction along with the aetiologies and frequency of third molar impaction are explained in a simple way.

Introduction to Third Molar Surgery: Part-2 Indications and Contraindication

Mandibular Third Molars  

According to George Dimitroulis, there are common and uncommon reasons for the removal of the mandibular third molar.   

Iridium Course Schedule

A 20 Weeks Course for ADC Part 1 exam

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ADC Exam Coaching in India- Prelims & Practical explained

Instead of reading text, if you wish, you can watch the video furnishing same information by clicking at the link given below

The Australian Dental Council conducts a series of assessment exams for accreditation of the scientific knowledge, technical and clinical skills and ability to make a clinical judgement in relation to patient care of an overseas dentist whose dental graduate degree is not recognised by the Dental Board of Australia.

Once an overseas dentist successfully clears the assessment process, he or she can register with DBA as a GP and can practice Dentistry in Australia.

Australian Dental Council assessment process is a three-stage process. The first is the initial assessment that I have already explained in the episode 1 of our video series. Now, in episode 2 of the video series, I shall explain written as well as practical exams. After going through this video, you will become familiar and confident with every aspect of the exams.

Oral Hygiene

Regular oral hygiene by mechanical brushing and cleaning between the teeth removes soft dental plaque. When dental plaque becomes mineralised (calculus), it must be removed by a dental practitioner. Dental plaque and calculus can cause periodontal disease (eg gingivitis) and dental caries.

Frequent exposure to dietary sugar and carbohydrates leads to an increase in the risk of dental caries. Avoid sucrose in sticky forms and limit other sugars (eg acidic drinks) and carbohydrates as snacks between meals.

Avoid drinks other than water at bedtime after brushing teeth (including milk, formula and expressed breastmilk)—saliva flow diminishes during sleep and the sugar from the drink remains on the teeth overnight. This is a common cause of dental caries in children and the elderly.

Interdental cleaning

Interdental cleaning using floss or interdental brushes is recommended once each day before brushing the teeth. Brushing teeth with a toothbrush does not remove plaque from between the teeth or below the gum line.

Dental floss can be used to wipe the interdental tooth surface to remove plaque (back and forth, then up and down several times on each tooth surface). Manual dental floss, floss-holding devices or automated flossing devices are available—the choice is based on personal preference or level of dexterity.

Interdental brushes areas effective as dental floss in plaque removal, and often more effective for debris removal. They require less dexterity than dental floss. Interdental brushes are particularly useful in patients with gum recession or disease, where the spaces between the teeth are larger.

Interdental wood sticks can remove food particles, but do not effectively remove plaque.

Water jets do not effectively remove plaque.

Tooth and tongue cleaning

Soft-bristle toothbrushes are recommended; hard-bristle toothbrushes are not more effective and can damage the gums and the softer root surface. Children younger than 6 years should use a children’s toothbrush. Powered toothbrushes with a rotation oscillation action are slightly more effective at plaque removal than manual brushes. Powered toothbrushes are useful for people with dexterity or disability problems, and for carers. Toothbrushes should be replaced once damaged or when the bristles become deformed.

Advise patients to use a fluoride-containing toothpaste; for recommended concentrations of fluoride in toothpaste. Toothpastes that do not contain fluoride provide little protection against dental caries. Toothpastes also contain other additives (eg abrasives, detergents, antibacterial, bleaches, remineralising agents).

Toothpastes that do not contain fluoride provide little protection against dental caries.

Advise patients to brush teeth for 2 minutes, twice each day with fluoride toothpaste. Toothpaste should be spat out and not swallowed to minimise fluoride ingestion; the mouth should not be rinsed to allow increased uptake of fluoride from the saliva.

Advise patients to brush or gently scrape the tongue, but not to brush or massage the gums.

Mouthwash

Mouthwash is usually not required as part of a standard oral hygiene routine, provided mechanical cleaning (toothbrushing, interdental cleaning) is performed properly. Mouthwash should not be used as substitute for proper mechanical teeth cleaning.

Fluoride-containing mouthwashes can be used as an additional source of fluoride for people at high risk of dental caries on the recommendation of a dentist.

Mouthwash that inhibits plaque formation (eg chlorhexidine) can be used for a short duration in addition to mechanical tooth cleaning, usually when pain associated with periodontal disease restricts mechanical cleaning (see Management of necrotising gingivitis and Gingivitis).

Alcohol-containing mouthwashes may be associated with oral cancer and are not recommended. See here for further information on mouthwashes.

Specialised oral hygiene

People with dental implants, bridges, crowns that are joined together, and orthodontic brackets should follow the oral hygiene advice from their dentist.

Denture hygiene

Dentures should be regularly cleaned twice a day to remove food particles and plaque. Advise patients to remove dentures from the mouth and clean them with warm water, mild soap and a toothbrush, denture brush or soft nail brush. Avoid cleaning dentures with hot water, toothpaste, kitchen detergents, laundry bleaches, methylated spirits, antiseptics or abrasives (unless instructed to by a dental practitioner). Patients should clean their gums and remaining teeth with a soft toothbrush and toothpaste.

Advise patients to place dentures in a dry environment overnight after cleaning them. Traditionally, it was recommended that dentures were kept in liquid overnight. However, allowing the cleaned denture to dry out at night is more effective for reducing yeast colonisation and plaque accumulation, compared with both denture cleansers and water. Although repeated cycles of hydration and dehydration can change the shape of the denture, these changes are small and not clinically significant.

Dentures should be cleaned then placed in a dry environment at night. If there is a build-up of hard deposits (tartar, calculus), dentures can be soaked overnight in a solution of white vinegar (diluted 1:4), then cleaned as usual. Advise patients to see their dentist for professional cleaning if hard deposits cannot be removed.

Denture-associated erythematous stomatitis is prevented by regular cleaning of the dentures and storing them in a dry environment overnight. Advise patients with denture-associated erythematous stomatitis to optimise denture hygiene—it can take 1 month for symptoms to improve; see Oral candidiasis and Candida-associated lesions for further information.

Ref: Therapeutic Guidelines Limited 2019 (www.tg.org.au)

Radiation Protection of Pregnant Women

Is there a safe level of radiation exposure for a patient during pregnancy?

Dose boundaries do not apply for radiation exposure of patients, since the decision to use radiation is reasonable depending upon the individual patient situation. When it has been decided that a medical procedure is justified, the procedure should be optimized. This means that the conditions should achieve the clinical purpose with the appropriate dose. Dose limits are determined only for the staff and not for patients.

Dental Amalgam: SAQs for Viva Voce

SAQ 1. A patient arrives at your office and expresses concern about mercury from dental amalgam causing her harm. What will you tell this patient to reassure her about the safety of amalgam? 

ANSWER: 

You will explain three facts of dental amalgam fillings:

(1) The mercury present in amalgam is not free. It is always tied up chemically in the dental amalgam matrix. It is never released into the body. The majority of bound mercury never leaves the dental amalgam mass.