- Also known as white spot caries lesion/incipient.
- Is the process in acid attack, where the calcium and phosphate ions are lost from the enamel. As the pH falls, we get increasing degrees of the dissolution. The breakdown of enamel crystals (hydroxyapatite) as the critical pH is 5.5.
- Demin is usually restricted to areas of plaque accumulation, and boarders of pits/fissures and lesions.
- Clinical Appearance: dull, frosty dehydrated white when enamel is dried. Loss of translucency of normal enamel.
- May be rough on probing/ tactile feel.
Remineralisation/arrested enamel lesions.
- Is the remineralisation of minerals from the saliva. Remin occurs at a neutral pH- rebuilding the partly dissolved apatite crystals.
- The saliva acts as a buffer, which remove acidic ions from the environment. The saliva contains a weak carbonic acid which attempts to bring the pH back to its normal pH of 6.8. Through remineralisation, the hydroxyapatite changes into Fluorapatite, which has a lower critical pH of 4.5 and is more resistant to acid attack.
- The process of remin is enhanced with the presence of fluoride ions- fluorapatite.
Acid and base strength:
- Acid: as with strong electrolytes, strong acids ionise completely in water.
- Bases: measure hydroxyl ions. Strong bases completely ionise producing hydroxide ions, and weak bases only produce few hydroxide ions in aqueous solution.
3 main buffering systems
- 1. Phosphate
- 2. carbonic acid
- 3. Protein
- Bicarbonate increases the concentration with salivary flow and maintains the pH of saliva above 6.3.
- The bicarbonate ions diffuse into plaque and neutralise acids produced by bacteria as a result of carbohydrate fermentation.
- Carbonic anhydrase assists removal of hydronium ions by catalysing the reaction
Amorphous Calcium Phosphate (ACP)
- Calcium and phosphate ions CAN crystalise.
- Amorphous state: not in structure or does not form crystals. Vital for the ions to be in this state to support remin!
- Calcium and phosphate are separated by statherine which prevents precipitation. The amount of saliva you produce is important to keep an amorphous state to keep it ready/available for remineralisation.
Calcium phosph peptides (CPP)
- Small protein in which serene amino acids are modified by the addition of a phosphate.
- CPP found in tooth mousse - helps to desensitise, stimulates saliva flow, and is less likely yo stain. Calcium phosphate ions also helps with bone growth.
- CPP can stabilise ACP by binding calcium and phosphate ions.
- During acid challenge, CPP releases calcium and phosphate which promotes remin
- It maintains super-saturated of Ca + P with respect to tooth enamel.
- Equilibrium favours enamel.
- CPP also binds to dental biofilm which enables it to release Ca + P ions during acid challenge.
Factors of Demin
- Lack of fluoride
- high amounts of carbohydrates and acidic foods
- Mature plawue (containing s mutans)
- Poor saliva flow/protection
Factors of Remin
- Adequate fluoride
- Low amount of simple carbohydrates and acidic foods
- Low levels of S. Mutans
- Good salivary protection
The ppm of the following products
APF gel foam
- Adelaide Water: 0.9ppm
- Junior Toothpaste: 500ppm
- Adult toothpaste: 1000-1500ppm
- Oral B: 1400ppm
- Neutrafluor 5000: 5000ppm
- APF gel foam: 12300ppm
- Mouth rinse: 200-600ppm
- Fluoride Varnish: 236000ppm
- Colgate: 1200ppm
What does fluoride do?
- Enhances remin by resisting demin
- Inhibits bacterial growth and metabolism
- Inhibits acid production (from bacteria-erosion)
- Fluoride promotes balance in the cycle of Remin/demin, therefore the prevention of dental caries.
- NO fluoridated toothpaste for 0-1.5 years old.
- After 1.5YO, introduce junior toothpaste (500ppm)
- Use small headed t/b
- Parental supervision until at least older than 6YO
- Pea-sized amount of child size t/p
- Encourage spit not rinse of t/p- DO NOT SWALLOW.
- Initially begin due to the interaction of bacteria that produce acid, a substrate that the bacteria can metabolise and many host factors (including saliva and teeth).
- An ecological imbalance in the physiological equilibrium between tooth minerals and oral microbial biofilms.
- Bacteria in the biofilm produce weak organic acids as a by-product of metabolism of fermentable carbohydrates. The acid causes local pH to fall below the critical pH (5.5 for hydroxyapatite) resulting in the demineralisation of tooth tissues. If calcium, phosphate and carbonate diffuse out of the tooth, a cavitation will eventually take place.
- Mechanical wear caused from bruxism (tooth on tooth wear) from actions such as grinding or clenching.
- Clinical appearance: wear facets on the occlusal/incisal surfaces, loss of anatomical features
- Implications: Failure of restorations, the jaw can rotate together more than they should, which is called loss of vertical dimension of occlusion, TMJ pain, Cracked/chipped teeth or restorations.
- Prevention: Important to work out what the causes are, such as emotional stress/anxiety, unaware, which will help with treatment plan. If attrition is due to emotional stress, consider calming exercises or professional medical advice may need to be seeked. Patient might need a night guard made to protect teeth at night, or jaw exercises for TMJ pain.
- Mechanical wear from actions such as brushing too hard. Most common at gingival/cervical margin.
- Clinical Appearance: Round notch at the gingival margin, exposed root surface (CEJ visible or the loss of enamel).
- Implications: sensitivity from exposed surface (gum recession), possible mobility.
- Prevention: Discuss toothbrush abrasion causes, technique, soft toothbrush, using a fluoridated/non-abrasive toothpaste always end with review.
- (often co-exists with abrasion and attrition) Acidic erosion from acidic foods/drinks that attack the enamel surface.
- Clinical appearance: appearance changes, sensitivity, colour of teeth changes as the enamel has been eroded away. There is sometimes a broad rounded cavity, divots on chewing surfaces, fillings may become prominent.
- Implications: sensitivity/pain with hot/cold and sweat things, and loss of tooth structure/surface potentially requiring RCT.
- Preventive plan: dietary advice- such as trying to limit acidic foods/drinks, drinking through a straw or diluting with water.
- Eating something such as cheese to helps to remineralise the teeth with calcium.
- Rinsing with water, and waiting at least half an hour before brushing with a fluoridated toothpaste.
- Chewing sugar-free gum to stimulate salivary flow- acts as a buffer against acid attack.
- Advice on alternatives
- Intrinsic acid sources: gastric acid (reflux) caused by conditions such as bulimia, gastroesophageal refulx disease- not brushing straight after, rinse mouth out with water, can smear tooth paste on teeth if needed.
- *Advise what the condition is doing to the teeth and future consequences.
- Undevelopment of enamel before erupting, which impacts the tooth structure. (enamel defect) Quantitative effect.
- Clinical Appearance/texture:
- can occur on any surface of crown and can occur on 1 tooth or multiple depending on the duration of the type of cause (illness or medication). Can appear as: Pitting, horizontal grooves, horizontal bands.
- These can trap extrinsic stains within them and thus can be stained brown.
- Hypomineralisation is the imbalance of nutrients/minerals causing a disturbance in the quality of the enamel.
- Clinical Implications: presents as a change in colour and translucency due to spaces/pores in enamel which are filled with water/protein and not mineral.
- Can occur on any surface
- Is shiny, white opaque patches or lines/spots with distinct or indistinct boundaries.
- In severe cases, may have brown stains areas within the white area.
- EXAMPLE- Fluorosis- excess fluoride and less calcium ions.