Questions about Local Anaesthetic

Your dentist has told you that your child needs a local anaesthetic at their next visit. You may be worried and have questions. We will discuss many of the common questions in this blog post:

What is local anaesthetic?

Local anaesthetic is a type of medicine given as an injection to temporarily numb a specific area of the mouth. 

How does it work?

Local anaesthesia blocks pain by stopping pain signals being carried by nerves to the brain. This causes a complete loss of pain sensation to a specific area, without affecting the rest of the body. Pressure sensations may still be felt.

Why is local anaesthetic (LA) used in dentistry?

Although shallow fillings can often be completed without LA, it is required for deeper cavities, treatment involving the nerve of the tooth and tooth extractions, among other procedures. Local anaesthetic makes painless procedures possible and therefore makes treatment easier and more comfortable.

What is the difference between local and general anaesthetia or sedation?

General anaesthesia (GA) is used when a patients needs to be asleep for an operation or procedure - this can only be done by a trained anaesthetist in a fully equipped hospital. 

In conscious sedation, a sedative is given either by mouth (tablet or liquid), injection, or inhalation (gas and air). The patient remains awake and responsive but is more relaxed and less anxious. Local anaesthetic is often used in addition to sedation or GA.

Local anaesthetic does not affect consciousness. Only the specific area of the body being numbed is affected.

Is Local Anaestheic safe?

Local anaesthetics are used routinely every day for dental treatment all over the world, with relatively few problems. 

As with all medication, care and attention must be taken to ensure local anaesthetic is used safely. Good dentists will use safe techniques carefully and inject slowly. To ensure a safe dose a child's size and weight need to be taken into account, as the maximum safe dose is lower for children than for adults.

Allergies to commonly used dental local anaesthetics are extremely rare. Allergies to preservatives used in LA have been known, although they are not common.

Epinephrine (adrenaline) is commonly added to local anaesthetics as it increases the duration of the numbing effect and also reduces bleeding. For patients with significant heart or thyroid problems LA without epinephrine may be used.

From what age can children be given LA?

Very young children are sometimes unable to cooperate for treatment with local anaesthetic. This is because they do not understand the numb feeling or the reason for it. With reassurance and explanation appropriate to the child's age, some children as young 3 years old can accept treatment with local anaesthetic. For young children who unable to cooperate, temporary treatment may be done to make the child comfortable until they are able to accept further treatment. If there is severe infection treatment under general anaesthetic may be required.

What if I or my child are worried about the injection?

Anxiety about injections is common and understandable. Finding a good dentist who is understanding and sympathetic will go a long way in reducing anxiety.  Relaxation or distraction techniques can be used. For very anxious patients, conscious sedation with inhaled nitrous oxide and oxygen may be an option. Talk to your dentist about your anxieties but try not to convey your worries to your child. In our experience at Small Bites we have found that the children are often are less anxious than their parents!

How can the dentist make it easier for my child?

Local anaesthetic should ideally be used when a child is cooperative and has accepted other treatment well.

Explanation and reassurance are very important. For a young child the dentist may say that they are going to give some special medicine or "sleepy juice" to make the tooth go to sleep for a while, so that they don't feel any pain while the tooth is fixed. Older children with more understanding may be told that this involves an injection.

A numbing gel placed on the gum for a couple of minutes before the injection often works very well, so that the injection is hardly felt. At Small Bites we also use a very fine needle which minimizes pain or discomfort during injection. 

It is necessary to wait 5 or 10 minutes to give the local anaesthetic time to work before starting treatment.

How long does the numb feeling last for?

This will depend on the technique used but usually between 1 and 3 hours. It should be explained to the child that their lip/cheek (and sometimes also tongue) will feel strange. The affected area will feel swollen/bigger but not look any different.

What precautions should I take after my child has had local anaesthetic?

Tell you child that the numb feeling will take some time to wear off. Care should be taken that they do not bite their lip or tongue during this time. Hot food and drink and any food that they need to chew should also be avoided until the feeling has returned.

If you have any other questions you can either talk to your dentist or leave a comment below.

Which foods cause tooth decay?

Your child's diet is one of the most important factors in developing dental decay and small changes can make a big difference. 

In the previous blog post we looked at how foods containing sugar combine with bacteria in plaque to produce acid. If the teeth are subjected to frequent or long periods of acid attack, decay becomes likely to occur.

Most people are aware that children who eat too many sweets and candies are likely to get cavities. However, any foods that are are high in refined carbohydrates (starch), such as crackers and chips, can cause decay if the foods remain stuck to the teeth for long periods of time, as the starch breaks down into sugar. In fact, one good way to determine if a snack is good for a child is to check their teeth 20 minutes after consumption. If the teeth are still filled with food, the risk for dental decay will be higher. These foods should be eaten only rarely and teeth should be brushed afterwards.

There are a lot of "hidden sugars" in processed food. If you read the ingredients, they may be labelled as sucrose, glucose, lactose, or fructose - these are all types of sugar. In addition to containing high levels of sugar, many children's breakfast cereals also stick onto the teeth. Even diet soda drinks and concentrated fruit juices can cause decay as they are acidic.

It is not realistic to ban your child from eating sweets. altogether. Instead, limit consumption of sweets and candy to maximum of once a day, preferably at the end of a meal. Those treats that dissolve and clear from the mouth quickly eg. a milk chocolate bar, are better than hard candies, lollipops or sticky caramels. Sweets should be eaten in one go, rather than continually snacking on them.

Children do get hungry and need to snack. Choose healthy snacks such as fresh fruit and vegetables, nuts, cheese. For drinks in between meals go for water or milk without added sugar.

What causes dental cavities?

When you consume any food or drink containing carbohydrate, or sugar, the bacteria in the plaque on your teeth metabolise it, producing an acid attack which lasts for at least 20 minutes. The acid dissolves the outer surface layer of the teeth (enamel).

The acid attack will be much longer if the food remains stuck onto the teeth, or if snacking continues over a period of time, eg. eating a bag of sweets one by one, or continuously licking a lollipop. Also, If babies or toddlers fall asleep with a bottle, or whilst nursing, the milk will remain on their teeth for a longer period of time.

If food and drinks containing sugar are limited to mealtimes, with sugar free snacks and drinks in between, the teeth can recover from these short periods of acid attacks. In the early stages of decay (before a cavity is formed), the enamel can repair itself by taking in minerals from saliva. Fluoride also helps to strengthen the enamel in this process.

However, with frequent snacks and drinks containing sugar, cavities become much more likely to occur.

Once the enamel layer crumbles, a cavity is formed, bacteria enter and the decay process spreads rapidly.

To prevent dental decay, the aim should be to reduce the amount of time that any food containing sugar is present in the mouth. Drinking water or rinsing after eating can help. Try to make snacks and drinks, between meals, sugar free as far as possible. 

 

Regular, thorough brushing to remove plaque build-up from the teeth will also help but, as it is not possible to prevent plaque from building up again after brushing, diet is of extreme importance in preventing cavities.

Top Toothbrushing Tips

Tooth brushing is an important healthy habit to establish early on. 

For babies, you can use a clean, moist cloth to wipe the gums and the teeth once they start to erupt. Change to a soft brush or finger brush once they have at least two teeth. 

Finger brush

Parents should be in charge of brushing until their child reaches the age of 6 or 7, and older children will still need encouragement and supervision.

For children up to 3 or 4 years it is easier to see and brush their teeth if they lie down with their head on your lap. Try to make brushing fun - maybe by singing a song as you brush.

For children under 2 years, toothpaste is not advised. Once you start using toothpaste, use a small pea sized amount and encourage your child to spit it out. If your child is unable to spit out after brushing you can use a non-fluoridated toothpaste. Whilst fluoride is useful for preventing cavities, swallowing too much can cause fluorosis and staining of the developing adult teeth. Even after they learn to spit, young children will still swallow some paste so a toothpaste with a lower fluoride content is advised until around 7 years old. Ask your dentist for advice on which toothpaste is best for your child. 

Tooth brushing at twice a day should become part of the child's daily routine.  Let your child see you brushing. Small children love to copy what their parent or older sibling is doing. If your child sees you brushing regularly, it will set them a good example to follow.

It takes two minutes to brush teeth well. It may help to get a timer, or use one on your mobile phone. Make sure that all tooth surfaces are brushed.

Toothbrushes should be changed every three to four months, or sooner if they show signs of wear. Although not essential, a toothbrush with a favourite cartoon character on it may help motivate your child. You can use an electric toothbrush, if you find it easier, as long as it is one designed for children.

If you sometimes forget or your child is reluctant, you could use a reward chart, on which you place a star or smiley face, each time the child has their teeth brushed.

Sealants

By age 19, tooth decay affects nearly 70 percent of all children. Left untreated, tooth decay, also known as cavities, may result in pain and infection.

One highly effective option to help prevent cavities is dental sealants – a thin plastic film painted on the chewing surface of teeth.


Dental sealants have been proven a safe and cost-efficient dental procedure for patients prone to cavities. Dental sealants are still underused, despite their advantages in averting tooth decay for an average of five to seven years. Studies show that many children are exceptional candidates for dental sealants. Parents should consider sealants as a preventive measure in their child's oral health.

Surveys show the majority of all cavities occur in the narrow pits and grooves of a child's newly erupted teeth because food particles and bacteria are not easily cleaned out. A risk assessment best determines if a child is a candidate for dental sealants.

Dental sealants act as a barrier to "seal-off" space between the tooth surface and any small food particles or bacteria that may otherwise cause a cavity in an "unsealed" tooth.

Paired with twice-daily brushing with a fluoridated toothpaste, a healthy diet and visiting the dentist twice a year to monitor the placed sealants are 100-percent effective in preventing cavities.

Remember that dental sealants do not protect against gum disease such as gingivitis, oral cancer or many common dental conditions. Regular dental checkups are vital to monitor overall oral health.

Early Childhood Caries

Is Your Child at Risk for Early Childhood Tooth Decay?

The average healthy adult visits the dentist twice a year. The average healthy 2-year-old has never been to the dentist. By kindergarten, 75 percent of children have never seen a dentist, yet dental decay is the single most common chronic childhood disease.

The culprit? A combination of misinformation about when a child should first visit the dentist, when a parent should start caring for a child's teeth and the frequent and long-term exposure of sugary liquids to a child's teeth. 


A child should first visit the dentist six months after the eruption of the first tooth. During this first exam, the dentist can teach parents the best way to guard against early childhood tooth decay by wiping down the teeth with a damp cloth after every feeding and remind parents to limit sugary beverages.

Frequent and long-term exposure of a child's teeth to sugary liquids is commonly called baby bottle tooth decay. Most parents are aware of baby bottle tooth decay but may not know that the long-term and regular consumption of sugary liquids in a bottle or cup puts children's growing teeth at increased risk for decay.

Unsweetened fruit juices and water are best for children to help promote oral and overall health. Fruit juice causes tooth decay if children are allowed to hold a bottle, cup or box of juice in their mouth through the day. If left untreated, baby bottle tooth decay can result in pain and infection. Baby teeth are important because they hold the place for permanent teeth and help guide them into correct position. Severely decayed teeth may need to be extracted, which could effect the development of permanent teeth, speech and chewing.

Caring for children's teeth beginning in infancy promotes good oral health care habits for a lifetime and increases the chances of a child maintaining healthy permanent teeth.

Tips for parents to decrease the risk of early childhood tooth decay:
• Wean a child from the bottle or breast by age 1.
• Use spill-proof cups as a transitional step in the development of children, not a long-term solution.
• Don't allow children to use spill-proof cups throughout the day. Save spill-proof cups for snack and mealtimes when increased salivary activity helps clean teeth.
• Drink sugary beverages through a straw. The best spill-proof cups to protect against decay are those with collapsible rubber straws.
• Introduce oral health care habits early.
• Wipe baby's gums with a damp cloth after every feeding.
• Introduce brushing with a soft-bristle brush and water when the first tooth appears.
• Parents can add a pea-sized dab of fluoridated toothpaste to the toothbrush by age 2