 Hello everyone, welcome back to a new session on dentistry and more. So today we have a new topic that is preventive resin restorations. So I mentioned this in my bit and fissure sealant session. This is a restoration rather than a sealant, a restoration we do when there is involvement of caries. So it is cutting enamel and filling up with materials compared to just sealing of the pits and fissures. So let's see more details about PRR or preventive resin restoration. So it is a very new technique where we have better advantage compared to the traditional amalgam restorations. But the main problem it requires a excellent isolation of moisture and saliva contamination and if it is properly done which has a very long term success compared to the traditional amalgam. And we know how amalgam is getting replaced from dentistry because of its limitations of its bone strength, emotional leakage and a lot of tooth need to be removed when we apply amalgam because it has specifications like it requires a minimum of 1.5 millimeter depth of cavity and a 90 degree but joint should be present. So we might end up removing a lot of normal tooth structure for the sake of amalgam restoration. So that all are removed from this PRR technique where we think of a more conservative approach where the minimal tooth is removed. So PRR uses both invasive and non-invasive treatment of mostly borderline or questionable caries. So mostly this non-invasive treatment we have seen in Wittenfischer sealant use that is a non-invasive treatment. The invasive procedure also involved in preventive resin restoration because it is a restoration. Sealant process and restoration process is entirely different. We will not be involving any of the cutting enamel but the restoration involves removal of tooth structure. So this resin placed in caries areas and adjacent caries susceptible areas and seals them from the local environment. So we can use both sealant and restoration on the same tooth depending upon the caries environment. Because we have deep bits and fissures of tooth surface we think of only sealant therapy. So we just apply sealant, we do not need to apply any restoration because there is no caries involvement. But the picture is not very clear, you can see a black marking, this is caries. So we can apply sealant on all these places but we need to restore this point. So that is preventive resin restoration. So we are restoring this point and sealing all other points. So if caries is present in one area or part of the Wittenfischer, so that particular area that is this particular area is restored and the remaining part is protected with sealant. So that process is known as preventive resin restoration. If we do just restoration also with minimal intervention with minimal loss of tooth structure it is known as preventive resin restoration. If it is along with sealant also it is known as preventive resin restoration. So the three types that is type A, B and C based on the extent and depth of caries relation. So this is type A which is confined to enamel only, the caries is confined to enamel. So we can just using a very small burr, we can make a very small preparation because it is only confined to enamel. So slow speed burr can do its job, remove any calcified enamel and we can use an unfilled resin or a sealant to restore the preparation of caries relation because it is very minimal involved. So an unfilled resin is fine or even a sealant can do. But whereas type B which is completely involved in enamel and it has just ended then where we need to apply more strength or material because filler content we need to add or a material with filler need to be placed because more material means more strength it requires because of the anstricatory load. So preparation also is by round burr size 2 and we need to remove as much as normal structure possible, minimal to structure possible. We don't need to remove unwanted to structure like for amalgam administration. But the type A is very bigger cavity completely involved in amel and almost the dentine but it doesn't reached a pulp. So what we do is we are going for a bigger large size burr and a bevel is placed on the enamel cavos of a smonchin and we need to use both the material that is unfilled resin layer then we have to use a filled composite. So both should be used because the cavity is very big. So type A, type B, type C as you can see unfilled, filled and a combination. Here we are using both unfilled resin and a composite. So what are the steps involved in the PRR? So the first process is profile axis then it should be isolated with rubber dam or cotton rolls. Any decalcified areas over the tooth surface to be removed with burr, acid etching should be done, then washing and drying, bonding agent to be applied and then cavity to be restored with sealant or filler material. So these are the basic steps we apply for any sealing or any illustrations which involves curing light, because acid etchant and this bonding agent is a steps which involved where we apply curing light. So type A, type B and type C has different approaches in preparation of cavity. So advantages is the minimal cavity preparation compared to the conventional amalgonystration because it prevents unnecessary removal of healthy tooth structure. So it seal carries and it also destruction of tooth. So this picture says how much it cost for amalgam conventional restoration because as you can see there is a lot of restoration present and once it goes here most of the tooth is restored because we are unwantedly removing the normal tooth structure for the sake of amalgam requirements. Ultimately we end up using the tooth but in PRR it is just the carries areas we are restoring or sealant we are applying where it is carries prong. So there is no unwanted removal of the tooth structure. So the longevity is obviously very greater than compared to the conventional amalgam. So nowadays amalgam is nowhere used in dentistry or we are using a conservative approach with minimal tooth loss. So loss of frustration and subsequent replos replacement proves to be less invasive than that for conventional amalgam. So precautions early loss of PRR is almost similar aspect and future sealants because of the insufficient etching. So it is very important to maintain the excellent isolation and moisture contamination. So these are the very critical steps even in the pitum-fisher sealants. The isolation and prevention of moisture contamination. If moisture is involved the longevity will be compromised. So that's all about preventive restoration there are three basic types and always keep in mind that sealant is different from preventive restoration one is restoration and one is sealant. In sealant there is no carries involvement. We are blocking the pitum-fisher which are carries prong. In preventive restoration we are restoring the carries spot but with a very minimal intervention because with type A, type B, type C along with if there is any areas which are carries prong without any carries involvement we can seal it off. So that's all about preventive restoration. It is a very small chapter it comes along with ART, pitum-fisher sealant and PRR. So I will come over with a new session on dentistry and more. Thank you.