Ask the dentist: Cavities and knocked out teeth
Monthly column by Dr. Derek Baram, Specialist Orthodontist, Director of Central Smile, and Founder of Braces & Faces
Are cavities contagious?
Absolutely! Kissing and sharing utensils are examples of how cavity or periodontal disease-causing bacteria can be transmitted from one person to another. For example, newborns have almost sterile mouths but soon oral bacteria is transmitted from their mothers or carers. Kissing couples can also experience development of cavities or gum disease which they didn’t have before if their partners have poor oral hygiene. So think twice before you share somebody’s drink or kiss somebody!
What should I do if my tooth falls out due to injury? Should I put it in milk?
A tooth being knocked out is a highly stressful ordeal. It’s important to keep the tooth in a safe storage medium and re-implant it as quickly as possible. The following factors are key to success:
– The health of the cells remaining on the root surface
– Integrity of root surface (ie. Is the root damaged?)
– Bacterial contamination (Did the tooth fall on a dirty surface?)
– Time outside the mouth (Immediate re-implantation is recommended to minimise chance of root resorption and gives 85% success rate)
– Type of storage medium
What’s the best solution to store the tooth in?
These are the options; from worst to best:
No liquid: Drying causes the cells on the surface of the tooth to die and should be avoided
Water: the worst of these mediums but better than dry storage, because of its hypotonicity (density), germs and neutrality. Using water will likely lead to failure of re-implantation or future root resorption. Working time: A few minutes.
Own Saliva: Immediately available but not recommended because of its high water content and germs in the mouth. Working time: One hour.
Saline: Ideal osmolarity (density) but lacks nutrients for the cells to survive for long. Working time: Two hours.
Milk: Works well because of nutrients, density, neutrality (pH). Working time: Six hours.
Hank’s Balanced Salt Solution: Used in biomedical research to support the growth of many cell types, this is by far the best solution. Unfortunately, it is rarely stored in first aid kits or places where traumatic events occur more frequently (e.g. sports fields or playgrounds). Working time: Three to four days!
Now go and see the dentist to re-implant the tooth ASAP!
