 Hello everyone, welcome back to a new session on dentistry and more. Today we have a new topic in fluorides. So that is topical fluoride methods. So basically there are two methods to apply fluorides. One we have covered already that is systemic methods. So that is like we consume fluorides by any as any compound or through water fluidation or through salt or milk. So it enters our blood circulation and get the benefit. So it goes to the teeth and bonds and it replaces the ions in tooth. It replaces hydroxyl ions and makes the enamel lattice very stronger. So by it creates a caries protective enamel. That is the mechanism of systemic fluoridation or how the fluoride helps tooth to prevent dental caries or a better tooth compared to the non fluoride that tooth without any fluorides. So whereas in topical methods it is entirely different because teeth has completely mineralized. So we are applying the topic, applying the fluorides on the surface. So this can be applied after the eruption of teeth but the systemic fluoridation methods can be done or can be performed even before the eruption of teeth. So it goes to the teeth structure while it getting formed. So teeth eruption happens very late because most of the teeth that is up to second molar get mineralized by the age of 6 or 7 but the second molar erupts at 13 or 14 age. So systemic fluoridation should be done before 6 to 7 years and topical we can do at any time mostly we do on the recently erupted teeth. So by definition topical fluorides are the delivery systems which provide fluoride for a local chemical reaction to the exposed surfaces of erupted tradition. So the indications are caries active individuals recently erupted tooth and people taking radiation therapy that can affect their salivary flow and periodontal surgery where the roots are exposed. So how can this topical fluorides be applied? So basically it can applied via a profession like a professional can do it if we go to a dentist and we can do from our home itself. So topical fluorides professional application was introduced by BB in 1942. So we know in systemic fluorides we give just 1 ppm or 4-5 ppm not more than that but here we are giving 5000 to 19000 ppm which is equivalent to 5 to 15 milligram fluoride. Why is that difference? Because in systemic is giving at very low concentration as it is entering into our bloodstream and it is affecting the mineralization stage of tooth. But topical we are giving on the top or on the surface of the teeth where we are using the post mineralization phase. You basically a tooth has pre eruptive mineralization and post eruptive mineralization. So 90% of the total mineralization belongs to pre eruptive. So we are utilizing systemic fluorides by this pre eruptive mineralization and just 10% post eruptive mineralization is topical fluorides target. So we need to increase the ppm to very high then only we get a net effect of 1 ppm. Because 1 ppm is optimal effect to prevent endocardies. So if topical fluorides needs to be at a net effect of 1 ppm it should be given at very high range because we are giving at a topical side and more than that just 10% utilization of the post eruptive mineralization. So that is professional application. In this application we commonly use identifiers most of the identifiers as fluoride and we can use mouth friends as gills. So it has basically less fluorides compared to the professional that is 200-2000 ppm but still it is very high compared to the systemic circulation. So the reason I already explained to you it was invented by BB in 1942. So what are the basic sources of topical fluorides? The first one is toothpaste, mouth rinses, professional applied gels, foam rinses and even our saliva as fluorides. So toothpaste we can applied while brushing, mouth rinses like gargling we can do gargling. Gills can be applied by professional, gels can be painted or using a mouth guard. So fluoride vehicles how professional application of fluoride done is using a fluoride vehicle that is aqua solution and gel. So the property of gel is which adheres to the teeth and eliminates a continuous wetting. If it is a solution we need to continuously wet the tooth but if it is a gel it adheres to the tooth and a continuous wetting is not required. And thixotrophic solutions which are special type of gels it is not a normal gel but a special type of gels. So what is that speciality is it has high viscosity under storage conditions and it becomes fluid under condition of stress. So when we apply it to the tooth we apply some pressure it becomes fluid and it enters to the inner and outer spaces so that is thixotrophic solution. This is a fluoride vehicles commonly used in professional methods. And we have seen a prophylactic paste so it has fluorides. When we do prophylax the tooth might lose it is a little bit of fluoride content from the top layer. So it can be replenished if we do a post prophylactic paste application. And foam is like it minimizes the risk of fluoride over dosage and maintain the efficacy. So foam we can apply. So it is basically lighter than conventional gel and very little amount is required. So it can be easily penetrated into the intraproximal area and it does not require any suction that is the biggest advantage of foam application. Next is fluoride varnish. Commonly we have two types of varnish one is durafit and fluoroprotector. So the advantage of varnish is the increasing the time of contact between enamel surface and the fluoride agent because it adheres to the tooth surface for such a longer period. So there is a lot of time for action of this fluoride agents with enamel surface. So durafit is a product with 22,600 ppm and fluoroprotector is another product which has less ppm that is 7000 sorry. And karex is another fluoride concentration which has lesser than durafit but has equal efficacy. Which is one of the product we used for prevention of enamel karex. So fluoride application this is paint on technique this is how we do paint painting. So it is just like using a brush we paint the teeth surface. So fluoride toothpaste commonly available toothpaste contains fluoride. So fluoride toothpaste are into the market around 50s and 60s. So once the fluoride toothpaste are into the market slowly the systemic water fluidization is vanished from the history because most of the plants were closed because the effect of systemic and topical wear in preventing dental karex were almost same. So I had to spend a lot of money for installation of a systemic rotation because we have seen already how much cost it requires for a plant setup. So the same effect can be obtained by using a toothpaste. So salive also has fluorides. So let's see what are the basic three solutions commonly used in topical fluoride that the first one is neutral sodium fluoride, acetylated phosphate fluoride or FBF and stannous fluoride. It can be applied either by paint on technique so this is the paint on technique we paint on the teeth surface by using a brush or tray technique. We apply the material, we load the material into tray and apply it. So aqua solution can be painted and the viscous gel can be used in a tray. So let's see what are the three methods, three compounds. So the first one is neutral sodium fluoride. So for that is 2% sodium fluoride which gives reduction of 30% of dental karex. So it is prepared by dissolving 20 grams of sodium fluoride in 1 liter of distilled water. So 20 gram we put in 1 liter we get sodium fluoride. So that is known as Knudsen's technique. So the basic procedures are we have to clean the teeth and apply it for 3 to 4 minutes. We leave it for drying for 3 to 4 minutes so it gets its maximum concentration. So beyond 4 minutes there is no point but the maximum concentration of this fluoride on the tooth surface can be obtained within 4 minutes. The procedure has to be repeated at different intervals. That is a second, third and fourth application will be there after 1 week interval. So we have to apply at 1 week interval so there will be 4 times application of this Knudsen's technique that is 2% sodium fluoride. So this 4 visit procedure is commonly seen in 3, 7, 11 and 13 years because it coincides with the eruption of different groups of primary and permanent teeth. This is very important because at 3 years there is primary molars, 7 permanent incisors and molars, 11 and 13 canines and primolars. So this has to be applied on recently erupted tooth to utilize the 10% age post eruptive mineralization. So the fluoride side is basically a stable product and we can store it in a plastic container. The taste is well accepted by the patients and it is non-irritating to gingiva. It does not cause tooth discoloration. But the main problem is it has to be repeated at 4 intervals of 1 week gap. That is the most commonly reported disadvantage of this neutral sodium fluoride because it is not applied annually or semi-annually. It is applied at week intervals and that has to be at 4 times. And there should be application at different age groups that is 3, 7, 11 and 13 if it is applied for the same person it has to be done 16 times. So each year 4 times at 1 week interval. So the second part is stannous fluoride, it is most commonly used at 8% age. So the 2% age sodium fluoride or it is known as neutral sodium fluoride. Second one is stannous fluoride 8% age. So this is prepared by 0.8 grams is dissolved in 10 ml of distilled water in a plastic container and it has to be prepared freshly and there is no stability. If you are using it for a patient you have to prepare it at the moment and use it. You cannot prepare and keep it for the next patient. So it is like 0.8 grams in 10 ml of water whereas sodium fluoride was like 20 grams in 1 liter of water, 20 grams in 1 liter of water whereas stannous fluoride is 0.8 grams in 10 ml of water. So technique is same, you have to keep it for 4 minutes, you have to dry the tooth, cotton rolls, isolate it properly, then apply it for 4 minutes. So it reaches its maximum concentration and you can repeat the application at every 6 months not like 1 week interval for 4 times like we seen in sodium fluoride. It has to be applied for twice that is 6 months interval for the 1 patient. There is no age category what we have seen in sodium fluoride. So the 4 minute theory I told you because the amount of fluoride reaches on the top of surface by 4 minutes. So even if you apply for 8 minutes there is no point, maximum concentration is achieved within 4 minutes. So 4 minutes is the ideal time. So advantage is only 2 application is needed unlike 4 applications and the base when the disadvantages are it is not stable you have to freshly prepare for each patient and it is quite astringent and its taste is little odd and application is unpleasant. So there is reports of tissue irritation and pigmentation of teeth. So none of these are present in sodium fluoride. So this is not stable and pleasant tissue irritation and gives pigmentation. So advantages are just like we have only 1 or 2 appointments in a year. So the last one is APF or Acidulated Phosphate Fluoride. So it is prepared by 20 grams of sodium fluoride in 1 liter of phosphoric acid that is 0.1 molar. 20 grams in 1 liter of 0.1 molar phosphoric acid then add 50 percentage of hydrofluoric acid and adjust the pH at 3 and fluoride concentration at 1.23. This is known as Brutfold solution. This is known as Muller solution. This is Muller's technique. The first one was Knudsen's technique. Stana's fluoride is Muller's technique and the last one is Brutfold solution. So this is prepared by 20 grams in 1 liter of 0.1 molar phosphoric acid then 50 percent hydrofluoric acid is added pH 3 concentration 1.23. Stana's fluoride method applies similarly just like Stana's fluoride twice in a year and kept for 4 minutes commonly used in gels. So gel applied by tri-method sodium fluoride and Stana's fluoride applied by paint on technique just like painting. This is applied in gels that is tri-technique. So 4 minute period is also same here and the tray we apply the material into tray and keep it using a saliva ejector to control the water contamination. So this is tray technique. We fill it one fourth of the tray height wise then we apply it like this maxilane mantable and keep it for 4 minutes. So advantages is just like Stana's fluoride 2 application in a year and gel preparation sorry, gel preparation is not like that sodium fluoride and Stana's fluoride where tray technique is being used and the cost of application is reduced. Disadvantages is practical difficulties are there and it is very acidic because of pH 3 and it cannot be stored in glass. So just compare this percentage was 2 percentage, 8 percentage and 1.23 percentage of fluoride. PPM is 9000 almost 20,000 and here it is 12,300 pH in sodium fluoride it was neutral here it was 2.4 to 2.8 almost acidic and it is also acidic and sodium fluoride total 16 application 4 at 1 week interval at 3, 7, 11 and 13 in years that is 4 years each year 4 application total 16 application this is bi-annually this is also bi-annually. Stana's fluoride has a lot of disadvantages to pigmentation, gel irritation freshly need to be prepared very freshly like that and most of the teeth most of the products gives a 30 percentage reduction. So the remaining products are dentifies small trinces and gels, dentifies commonly we apply the most of the toothpaste has fluoride and our trinces we can give it for children under 6 years of age it can be rinsed it will give caries protection then methods is nothing but 5 ml should be rinsed before bed and switch between teeth for a 60 seconds. Okay so that's all about topical fluorides so the most important things are these ones sodium fluoride, stana's fluoride and APF so stana's fluoride has most disadvantages and we need to remember this table percentage, ppm and ph frequency of application. Okay I'll come up with a new topic that is prevention of dental caries by fluoride in my next session okay thank you.