Q1. Does Odontocide clinically stain teeth?
No, you do not have to bleach afterwards.
Q2. What is the difference between Odontocide and Odontopaste?
Both Odontocide and Odontopaste have antibacterial and anti-inflammatory properties. Odontopaste achieves this through an antibiotic/steroid combination and Odontocide through calcium hydroxide/NSAID combination. Odontocide has superior antibacterial properties compared to Odontopaste. Odontopaste has superior anti-inflammatory properties.
Q3. Why is Odontocide only mildly radio-opaque?
The radio-opacity of a calcium hydroxide paste is due to radio-opaquing agents and not the calcium hydroxide. The only purpose of radio-opaquing agents is on the day of application, to detemine the extent of application. Following this, there is no correlation between radio-opaquing agents and the chemistry of calcium hydroxide present. The radio-opacity in a followup radiograph does not indicate how much calcium hydroxide is left in the canal and does not indicate whether the applied calcium hydroxide has converted to calcium carbonate. The only information which a followup radiograph can convey is the extent of healing in the periapical tissues and the amount of radio-opaquing agent left which has no biological effect. This was identified as part of the design examination process when developing Odontocide and although it goes against the clinical habits of many dentists, it does represent the correct application of the chemistry of the ingredients.
Q4. Why does Odontocide have 20% calcium hydroxide whilst other formulations have higher percentages of up to 40%?
Odontocide contains 20% calcium hydroxide. The level (%) of calcium hydroxide is commonly used as an indicator of the effectiveness of the paste. This is an incorrect assumption. The effectiveness of the calcium hydroxide-based paste is better correlated to the pH of calcium hydroxide in solution. pH is determined by the solubility of calcium hydroxide in water and by the dissociation constant of calcium hydroxide. Calcium hydroxide has a high dissociation constant meaning that most of the calcium hydroxide which dissolves converts to free hydroxyl ions and calcium ions. The hydroxyl ions are responsible for the antibacterial properties of the paste. However, with only 1.73 grams of calcium hydroxide dissolving in one litre of solution, the concentration of hydroxyl ions is low and this is why calcium hydroxide achieves a pH of approx. 12.4-12.6 whilst other similar compounds such as sodium hydroxide and potassium hydroxide, which are far more soluble, achieve a pH of 14.
Theoretically, if more than 0.173% calcium hydroxide is present, then the pH will always be the same as anything more than 0.173% cannot dissolve into solution and is effectively inert. So a 0.173%, 5%, 10%, 20% 40% calcium hydroxide paste wiill all have the same pH. The only advantage of the higher % calcium hydroxide paste is that it lasts longer within the canal. As the calcium and hydroxyl ions are lost through disolution then more calcium hydroxide dissolves to replace the amount lost. Therefore the higher percentage pastes will last longer. How long? Well that remains unknown. However, there are several calcium hydroxide pastes on the market, other than Odontocide, which have only 20% calcium hydroxide present, and they have been used for many decades. eg. Calcipulpe and Calxyl (slightly more than 20%).
Odontocide is therefore not compromised in terms of its antibacterial properties because of its lower calcium hydroxide percentage.
Q5. How does Odontocide "achieve" a pH of 12.5?
It is not accurate to refer to a pH of a paste which is not aqueous-based when drawing comparisions to calcium hydroxide-based pastes in different solvents such as water. However, due to criticisms from our competitors regarding ADM not providing a pH we decided to phrase it as "it achieves a pH". It only does this when the solvent used in Odontocide, polyethylene glycol, is displaced by significant amounts of water. The pH of a paste in a non-aqueous solvent cannot be compared to a pH in an aqueous solvent. This is a well known fact in electrochemistry, however, of which dentists are not aware. It is best to think of pH mesures in two different solvents as two temperature scales, Celsius and Fahrenheit. You can measure temperatures using either scale but you cannot compare their direct measures unless you convert the scales. pH is even more complex as no conversion exists between different pH measures in different solvents. It is simply impossible to compare pH of aqueous to pH of non-aqueous such as polyethylene glycol. Unfortunately most dentists do not understand electrochemistry and are unaware of this fact. Odontocide therefore "acheives" a pH of 12.5 but only when placed within the root canal and where the solvent has been displaced with water. It is the only way of making a statement regarding pH which is accurate in terms of the science and chemsitry involved. It is unfortunate that some companies attempt to mislead the dental profession by stating that they have a paste with a pH of greater than 14 in a calcium hydroxide/polyethylene glycol mixture. This is simply not possible.