Dentin determines the destiny of teeth whitening. The brightness and color of teeth depend upon the condition of dentin, which is composed of minerals, water and protein.
Dentin is the second layer, behind the enamel and is comprised of bone-like tissue but softer than bone.
Enamel is thin and semi-translucent; light reflects through it on to underlying dentin, which varies in colors depending on age, race, gender etc.
Enamel is tough and although it can be repaired in the initial stages of damage, it can’t be grown back.
Enamel stains are extrinsic and excessive damage to enamel will expose the state of dentin. Dentin discoloration falls into the category of ‘intrinsic staining’, which is factored by interrelated forces.
These factors are largely age dependent either occurring in formative years in life or later, known as pre-eruptive and post-eruptive respectively.
How does dentin discoloration occur?
1. Pre eruptive staining
Unbelievably, dentin discoloration takes shade while a child in growing in the womb. Pre-eruptive dentin staining encompasses elements in the developmental period of teeth that cause discoloration.
Excess fluoride consumption from toothpaste and water during pregnancy and childhood, can cause dental fluorosis, having cosmetic implications.
This causes a decrease in the mineral content of enamel, increase in pitted surfaces and porosity.
It makes enamel fragile and frail, to affect and alter dentin.
Tetracycline is an antibiotic used in the treatment of bacterial infections.
If the antibiotic is taken in formative years – during pregnancy and early childhood, it changes the structural components of teeth.
Tetracycline affects both enamel and dentin. Dentin discoloration with tetracycline is influenced by the dosage used, length of use etc.
The discoloration is permanent, can be seen through enamel as yellow- green initially, which is later oxidized to gray or brown.
Certain genetic predispositions can cause discolored and pigmented dentin. People with genetic tendencies to staining are more vulnerable to staining as children and adults.
2. Post-eruptive staining
Post-eruptive staining covers factors that strike after the teeth have fully developed.
Extrinsic staining also figures through decay and discoloration that touches the dentin through fissures enamel damage.
Dentin discoloration is a sometimes a consequence of trauma. Injuries due to dislocation or displacement can cause a red tint.
It then turns into a blue-brown stain as the blood decays.
The dental pulp is the center of a tooth made up of tissue and cells. Death of the pulp due to injury causes a release of a grey shades into the dentin.
Sometimes due to injury, hard tissue grows along the wall of the root canal, which causes a yellow discoloration.
Cavities or dental caries is a decay of teeth due a build up of bacteria.
An interaction of sugar, acid and demineralization brought on by poor hygiene causes damage to the enamel and dentin.
Cavities start as flaky white spots, gradually spreading to range in shades of yellows and browns to black if not controlled.
The process of getting a root canal can cause stains, if the dentist oversees clearing out pulp tissue from the tooth.
At times, left over liquid sealants and medications used, can cause staining to the dentin.
Silver amalgam fillings at the crown of a root canal, are corrosive and a major culprit in staining the tooth into a dark gray color.
Areas that have been overlooked leading to gaps between tooth structure and material used in restorative treatments such as composites and glass ionomer cementing can cause a discoloration to occur.
These are stains caused by a number of external factors like acidic food and beverages, plaque, tartar, smoking etc. exacerbated by poor dental hygiene, which can damage enamel to the level of dentin.
A person’s age can be a factor in discoloration.
As the enamel thins out with age, it exposes the health of dentin beneath, which makes this discoloration a mix of intrinsic and extrinsic factors.
Prevention of Dentin Discoloration
Timely dental hygiene, avoiding certain habits and including a healthy diet has oral benefits and falls into a preventive process of avoiding discoloration.
Early stage intervention strategies work on staining of dentin to prevent loss of tooth structure.
1. Pre eruptive stains
Intrinsic stains formed in formative years would be delicate to manage at home but that doesn’t mean oral care and hygiene should take a back seat.
In fact, it would make regular care even more crucial to avoid any further damage to already fragile teeth.
Pre eruptive intrinsic stains can be avoided by limiting exposure to fluorides during pregnancy and early childhood.
Fluorosis mainly forms in the time between 15 to 30 months. A faint form of fluorosis, enamel fluorosis manifests as loss of translucency white spots, and grooves.
Once the enamel is formed however, fluoride will not discolor teeth.
3. Tetracycline stains
All drugs related to tetracycline (Chlortetracycline, demethylchlortetracycline and oxytetracycline) can cause discoloration.
Tetracycline finds its way through the placenta to affect the emerging tooth. It should be avoided during pregnancy and in early childhood until the age of twelve.
4. Post-eruptive stains
The goal of oral care should be to stop the formation of bad bacteria and prevent dentin discoloration. To meet these goals, practices such as timely brushing, flossing and mouth rinses with mouthwash would suffice.
Water rinses after every meal are also a great way to ensure food particles don’t stay in the mouth. A rinse with water after wine, coffee or other drinks and foods that can stain teeth, is a dentist recommendation. Regular cleanings by a dental hygienist also help to prevent dentin stains.
Treatments with fluoride and dental sealants would help to prevent an increase in cavities and subsequent dentin discoloration.
6. Root canal stains
Root canal discoloration is best avoided through a preventive plan.
The dentist can enable this by securing root canal fillings the root and keeping them out of the way from the crown of the tooth.
7. Trauma stains
Intrinsic dentin stains that begin by damage to a nerve in a tooth occasionally can be avoided.
Root canal can remove the pulp section of the tooth before it has a chance to damage and discolor further.
8. Foods and beverages
Diet and nutrition play an important role in oral health and both nutrition deficiencies and overconsumption increase susceptibility to dentin discoloration.
Frequent consumption of sugary and starchy foods and beverages should be decreased and alcohol should be consumed in moderation. Habits like smoking should be controlled.
To conclude, pre eruptive dentin discoloration is largely dependent on preventive measures and informative choices during a child’s development.
Post eruptive discoloration can be avoided in early stage detection and adequate oral care.
For dentists to make an accurate diagnosis, knowledge of the cause of discoloration is of importance to choose an effective treatment plan.