Week 5 Lecture tutorial

Added: 2026-05-23

[00:00:00]hello and welcome back to the Colorado Dental Assisting school lecture tutorials we are on week five and we are going to be talking about cavity preparation and that involves composite and amalgam filling material we're going to discuss liners cement impressions and model trimming let's get started what you will learn today differences between composite and amalgam and additional materials that we use for restorative procedures why we use these items you will learn restorative instruments needed for both composite and amalgam you guys have already started learning the names of these instruments since week two but today we're going to talk about why we use them what material and what they do in the mouth you're also going to be learning how to mix alginate take impressions and pour up models and of course trim those models and in this lab you guys will be making bleach trays which is always a lot of fun cavity preparation what is a cavity or caries cavity inside of a tooth is when the tooth has decay in it so when a tooth starts to grow decay on there from lack of brushing and the plaque building up to long possibly maybe not getting a cleaning when they needed to and there's calculus stuck to the tooth causing caries maybe it's a restoration that has failed and started to leak and has some micro leakage that could also cause recurrent decay as well any time we have a cavity in the tooth we need to restore it because we are in the business of saving teeth so we want to make sure and restore that tooth so the process and removing diseased tooth structure while leaving a limited amount of healthy tooth structure to maintain a restoration and what we would call cavity preparation there are many there are actually five classes of cavities so your class one is a one surface lesion involving pits and fissures of the tooth an example of that would be your occlusal surface your class one for example could be 19 occlusal so that means we just have a small cavity on the occlusal surface it could go really deep into the tooth or it could be pretty superficial it just depends on how long the cavity has been there in the extent of the decay all of these items and information you want to put into your chart note so we always want to list the tooth number and the surface that the cavity is being restored on a class-2 cavity is the extension of a class one cavity into a proximal surface of the premolars and molars so we're only talking posterior teeth so your premolars and your molars in class two a lot of times people get these cavities because they don't floss they're not flossing as often or they're just not flossing at all and the only way we can clean and approximately between our teeth is to floss so an example of a class 2 cavity would be a number 4 emoji possibly a number 4 mo or vo it doesn't have to be all three surfaces it just depends on where the decays and class three is moving more anterior so this is the interproximal surface of your incisors and canines and we're talking about incisors are talking about our laterals and of course our front teeth so anytime that we have a class three for example could be number 25 your central incisor could be a medial incisal distal could be a medial incisal a distal incisal so this is the interproximal surface of your anterior teeth so again the patient is not flossing like we want them to your class 4 and class 5 cavity classes the class 4 involves a larger surface area including the incisal edge of the incisors and canines so an example of a class 4 would be let's say number 6 medial incisal distal facial or possibly mesial incisal facial distal in size a lingual it will cover not only all of those surfaces but they could be two separate cavities on the same two as a class for your class five is going to be the most common one referred to and what I mean by that is a lot of times the doctors aren't going to tell you hey we have a class for number six mi BLS right that's just a lot going on they're just going to tell you number six needs an EM ID or number six needs a mi DL in a class-five it's very commonly referred to so this is a smooth surface restoration it can occur on the gingival third of the facial or lingual surface of any tooth so anterior or posterior and what we're talking about is right along the gingival line right along that gingival line where people aren't brushing taking the time to really go in those small little circles and get right underneath that focus area and clean it out they're just possibly brushing too quickly going back and forth and missing that surface completely a lot of times when patients have recession we can see class-five along the gum line because they have a root surface that's exposed and our dentin layer is not as strong as the enamel so an example of a classified restoration could be a number 30 buccal 5 that would be B 5 is the way root chart it or it could be a number 40 lingual size so we're talking class 5 on the lingual or buccal surface restorative we are part of the restorative team that's what we do we assist the doctor all day long and we restore teeth so restorative is a term used in dentistry that describes the ability to remove decay or disease and bring back the proper function of a tooth in dentistry we use a variety of materials amalgam composite resin gold and each material will have different properties that we are going to talk about today here's the properties for proper restorative materials we need to have low solubility adhesion mechanical thermal change electrical and corrosive we are going to talk about all of these individually let's start with mechanical first of all any force push or pull on a matter in stress and strain causes that mechanical pull and push in the mouth the mouth is capable of twenty eight thousand pounds of pressure per square inch and a single cusp of a molar when you're chewing and biting down if you're a clencher and you're really kind of bearing down on those cuffs so anytime we put a restorative material in the mouth we need to make sure not only can it handle this kind of mechanical pressure but it can also handle handle the thermal change electrical and corrosiveness that goes on in the mouth every day let's talk about thermal change this happens every day all day hot and cold right so this hot and cold that's happening in your mouth is going to cause contraction and expansion and each time that happens with a restorative material it breaks down just a little bit more amalgam has a mechanical retention by using force and when needing to be replaced it's because of stress and strain over time that will wear down the material although this material will last longer than composite for someone who grinds their teeth composite on the other hand is a more aesthetically pleasing restorative material that we can use because we can match the tooth color however we do still use amalgam in Samoa posterior filling every day we can use liners to help protect the tooth from that hot and cold sensitivity depending on how deep the cavity is the doctor will decide whether or not a liner is needed for treatment electrical sometimes when you have a amalgam filling in the mouth you can have what's called galvanic shock and this is result from two different types of metals touching saliva which contains a lot of salt depending on your diet and carbohydrate intake the it can be a conductor of electricity so what happens is let's say you accidentally touch a metal fork to your amalgam filling it can give a galvanic shock and it kind of feels like it's pulling that filling out of the tooth which is a really strange filling so if your patients that were asking about it it is something that can happen corrosive corrosion happens in the mouth every day depending on what type of foods we eat and how well our homecare is so the reaction of metal that occurs within a metal when it is exposed to corrosive factors such as temperature humidity and saline so sometimes we eat you know acidic food of course our saliva is trying to remineralize our teeth and it's helping our teeth but not so much our restoration any surface discoloration on a restoration a lot of times we can polish it away sometimes on enamel we can polish away depending on what type of intrinsic or extrinsic staining it is the doctor will go around with their Explorer and make sure and check everything on the exam so that way they know whether or not one of these existing restorations has failed or if it's still functional and can stay in the mouth and does not need to be replaced solubility any materials placed in the mouth must be considered low solubility so that means we don't want it to dissolve in our saliva right so it has to have a low solubility this is so important in dentistry retention the ability to hold two things firmly together when they will not adhere to each other naturally when we're talking about amalgam fillings this is mechanically sustained in the mouth so what that means we do not use any sort of chemical bonding or cement to keep it in the mouth we simply push them amalgam down deep into the prep and a lot of times the doctors will do what is called a retention prep so they're going to take more of the tooth structure away so that way we have enough room for it to expand and mechanically sustain itself inside of that tooth it's going to take 24 hours for the amalgam to completely harden this is something you want to let your patient know when you're giving post-op instructions ask them to chew on the opposite side of the mouth and let them know if it comes out that they need to come in immediately to have it replaced composite however is bonded to the tooth so when we're placing composite we need it to be completely dry in the area we cannot have any human saliva or water inside of that cavity prep we need to have it completely dry we will use a system that h that uses h bond and a curing light to completely fill in the composite into the tooth which we will go over later on in this lecture when we are placing amalgam and it's mechanically sustained in the tooth the tooth can being wet it's okay because we're not using any sort of bonding system or cement it doesn't matter if they're still IVA or chemo or any sort of water in there because again the amalgam is going to expand into that press and stay in there mechanically it's not being cemented in or bonded with any sort of chemicals amalgam amalgam consists of several different materials silver being the predominant so they use silver for strength there is also tin for workability copper is also added in there for strength and corrosion resistance which is really important and zinc will help suppress the oxidation when we add mercury to this sort of dental alloy that's when it becomes amalgam and that's why it's so important that there zinc in there to suppress oxidation because we don't want that to leak into the body once it's completely hardened it does not leak it does not oxidize there isn't any mercury coming out of that filling mess in the body the only time the patient or the dental assistant or Dennis will be exposed is when we're placing or removing amalgam materials so some of these can come in powder form and they're mixed with mercury to form a soft pliable mixture we usually use them in molars and premolars it's not that common that we put them on lingual surfaces anymore that was a older technique that we used to use but now that we have composite and it matches majority of the time patients are going to choose composite because it's more aesthetically pleasing we do still use AM album on a weekly basis it's a great material and it is safe as long as we have our hve next to the amalgam when it's being placed the patient shouldn't be swallowing any of it they shouldn't really come in contact with it at all other than in the tooth so it's up to us to make sure and keep the area clean and make sure that we dispose of it properly whenever we're using amalgam we need to dispose of any excess amount amalgam or are trapped into the amalgam bins or containers in your office so when you do get hired on and they start giving you a tour make sure you know where the sharps container is contaminated waste and of course the most important amalgam bin because we do not want to be throwing any of this into our regular trash and it going out to our fields it wouldn't be good amalgam usage primary and permanent teeth a lot of times we put this in primary teeth because it's a lot easier place because kids tend to salivate a lot more than adults do and it's harder for them to stay open longer when we're placing composites so they're going to lose that tooth anyways this is a lot cheaper option any stress bearing areas of the mouth amalgam is the best thing you could do for posterior teeth if you have someone who's a clencher and grinder it's going to withstand a lot more pressure and it won't break down as easy as the composite well any patients who have poor oral hygiene again this is going to withstand a lot better and if moisture control is an issue so we talked about that so when we're placing amalgam fillings in children's mouths and it's harder to keep that area dry because they closed or possibly their saliva glands are you know just running high and it seems like Niagara Falls in there it's a lot easier to use amalgam it is composite the amalgam controversy it's harmful to patients due to mercury content harmful to the doctor and the dental assistant when mercury is combined with other alloys its chemical properties change making it harmless people are exposed to more mercury in some foods than a restoration in the oral cavity and the doctor and dental assistant take protective measures so like we talked about we dispose of it properly we also use our high volume evacuation suction in the patient's mouth and we aren't touching this with our bare hands we're wearing gloves and we're also using our instruments to move it into the patients tooth this is an example of the amalgam tub and tray set up so you can see your instruments here on the left and materials on the right this is a basic setup for an amalgam placement let's review these instruments amalgam carrier is going to be used to put them album into the tooth so once we put in the trader and it shakes it up for us and it bursts open that mercury packet that's inside the car fuel that's when it becomes amalgam and we mix it up with the dental alloy we will use the amalgam carrier will fill up both sides of the amalgam carrier a little a little hole there will be filled with amalgam and the doctor will push that lever and it will extrude it into the tooth and then they're going to use one of the burnishers to push it down deep into that cavity we have several different burnishers give the example that you see here is a football we also have a ball and an acorn furniture that you will see in the lab we can use these for composite placement as well but they were originally amalgam instruments the next instrument on be below the football burnisher is our amalgam plugger you'll notice the amalgam plugger has a waffle edge to it it has a more blunt tip the composite instruments that you are going to be seeing are more rounded and soft with this one has that more blunt edge the amalgam plugger is nice too has a small and a large end to it to use to push down uml them into the posterior teeth once the amalgam has been placed and packed we want to carve it and shape and Mattamy into the tooth right we don't want to want some big square tooth in the mouth the patient's not going to be able to close down so as the amalgam is hardening we're going to start carving well if you're an IDI you can go ahead and start carving otherwise the doctor will start to carve out the anatomy of the tooth one of the instruments that they can use for this is the discoid Cleo you can see on the blown-up pictures it has two different types of Carver's on both ends you will see this instrument in your lab as well and also the interproximal Carver sometimes we call an ITC or a Hollenbeck both of those names you will learn but it is an inter proximal Carver so it will help us carve that Musial and distal surface of the amalgam if the amalgam gets too hard to use a handheld instrument like this the doctor can always use their high speed and go ahead and carve in the anatomy that way all those little pits and fissures this is an example of the amalgam capsules they can come in one or double spill and what that means is whatever the whatever we order really it just depends on what we order and you can see here they come in different colors but if we have a single or a double spill it just depends on how big the cavity is that we're filling if it's only a one surface we can use the single if it's a three or five surface filling you want to go with the double that way you're not going back and forth having our Church freedom and open so many capsules because there'll be more to use in the double fill the other instrument you see here is the amalgam well so once this capsule has been treated and shaken up you're going to push you're going to open it up and pour the amalgam into the amalgam well and you'll see is the soft pliable mixture this is an example of the church raider so it shakes it really really really fast and then we take it out we put it inside the amalgam well and then we use our amount of carrier to pick up the amalgam we hand it to the dentist and he fills in the tooth what you see here is a matrix and in wedge placement so anytime we have interproximal space of the tooth that we're rebuilding we want to use a matrix and to hold all of that restorative material into the tooth otherwise if we were to put composite or a mouth over there it would just kind of slow down outside of it or we'd have one giant tooth and we wouldn't be able to floss in between we definitely don't want to do that so this matrix band is specifically called apostle Meyer that is the type of matrix band that they're using here this metal one is reusable the band itself is not we would throw away that band and then this metal piece here which is the top a layer would be sterilized the wooden wedge is one time used as well so this band around the tooth would be one time used and this wedge if we had an mo D we would need a wedge on both sides so the reason that we place the wedge in there is to completely imaginate that matrix band around the tooth and make it nice and tight so we don't accidentally push in the filling material below the gum line we don't want any restoration overhangs here's a close-up picture of what the wedge looks like in between the teeth and how it fits that matrix been in our nice and snug isn't it another example on the bottom of the amalgam restoration as it's completed the articulating paper has some marks on the teeth here showing the correct spot where we want the patient to have pressure we don't want a big mark on the inside of the pits and fissures here or this tooth will get very store all right let's talk about composite resin composite resin is not as strong as a mouth on our gold but it is designed to meet the recommended criteria for restorations and we actually have had a lot of success with it for many years now it is made up of a chemical mixture including an organic resin matrix inorganic fillers a coupling agent and of course pigments the composite components the matrix is a fluid like material called dime psych relate the filler has corks glass and silica which is a white crystalline compound the coupling agent adds strength to the resin by chemically bonding the matrix to the filler and the pigments help us match those shades that we use for our shade guide let's talk a little bit about your instruments for composites these are the instruments you guys have been learning since week two so now we're going to talk about what they do and why we use them first of all we always need a basic setup so we have our mouse Mayer Explorer pareo Pro or buy stick cotton pliers and an air water tip the condenser is going to be next we use a condenser a burnisher a plastic any of those instruments to place composite material we also will need our articulating paper holder with articulating paper to check the bite a curing light and a composite gun Composite instruments so what you see here on the upper right is a plastic instrument it kind of looks like a flat paddle it is used on anterior to piece to place composite resin so this helps us place it and the doctor will be using it for the facial lingual and incisal edges the next one is our condenser which is used on posterior teeth to place our composite resin that when the doctor will be using on the occlusal surface to push down deep into that cavity prep and make sure that it's completely filled a couple other instruments that we like to use are the burnisher so you can use the ball burnisher the football or the acorn and that can help condense and also create anatomy in the composite resin before we cure it and completely hardened bat material the articulating paper is going to hold our articulating paper and help check the bite once our restoration is completely filled so we are going to use that for composite and amalgam any fillings that we place in the mouth we always want to check the bite on to make sure that it's not too high this is an example of our composite tub so we have all of our materials and here our matrix fans a pan dish micro brushes interproximal wedges some disks in there ash and bond composite let's talk about each one of these and go into a little more detail on why we use them so the first thing you see here is the etching liquid is which is a so it can come in a bottle like this and we dispense it into a Dappen dish this one is a disposable Dappen dish or it could come in a syringe it just depends on how we order it so don't want you you know to get too hung up on what this looks like because it just really depends on how we order the etch and what type it is manufacturers make them all a little bit different on B this is our bonding agent so we are going to be using that to help bond the composite into the tooth this is the Dappen dish and then of course your micro brushes the micro brushes are going to be used to grab the etch in the bond and place it inside of the tooth and they're really small because we have a small area that we're working on so here's another example of different types of edge and bonding systems so again don't get too hung up on the bottle because it could come in a syringe like this this syringe is reusable however the tip is not this tip is one-time use only then we would take it off very wet spray it and put a brand new clean tip on a team so this is a phosphoric acid it's placed on enamel and dentin surfaces of the prepared tooth the purpose is to remove the smear layer left behind from the cavity preparation so the smear layer is our chemo which is our blood saliva and water and any sort of tooth debris we want to clean all of that out so it's going to remove the smear later it's also going to open the dentin tubules for bonding strength and it's placed anywhere from 15 to 30 seconds depending on the procedure you're always going to rinse for the same amount of time that the edge was placed on the tooth so remember that any time if you've done 15 seconds which is the most common for Venton layers if we're doing 30 seconds that's the most common when we're on mammal and we haven't prepped the tooth it all so in children when replacing sealants we're usually going to etch for 30 seconds and you want to rinse for the same amount of time so etch for 30 rinse for 30 X for 15 rinse for 15 you do not want to dry for the same amount of time though so please don't get those two confused you will rinse for the same amount but for dry and you're just going to dry it real quick with a puff of air real quick you're done you want to avoid desiccating or over drawing the tooth if you do that it could cause increased post-operative sensitivity what happens is the collagen and the tubules will collapse and it could cause a really bad sensitivity after the filling its place so you do not want to over drive a tooth this is another example of different types of bonding agents they all come a little bit different somewhat have a step a and B or one and two where it has prime N bond some of them come in these little capsules that are one-time used only and this has the primum bond all inside of it in one step so it really just depends on your doctor and what they like to use so the bonding is going to be put in the dentin tubules so they're cut and left open microorganisms during the to preparation could go inside of there so the bond is going to go into those tubules protect it and seal up the pulp of the tooth they can come a self cured which means we have to wait a certain amount of time for secured it could come in dual cured or a light cure and dual cared means it can do either or it can be self cured or light cured or some of them are strictly light cured a lot of times to speed up the process the doctor will have a slight period because the patient has already been open for a while while we've prepared the tooth and we don't want them to sit there open for too long and their jaw to get sore you're always going to follow the manufacturers directions so this next slide is showing you an example of the composite preparation so the cavity has been prepared we the doctor has removed all the decay the next thing they're going to do is line it and fill it all the way up with the etch we're going to wait 30 seconds or 15 seconds depending on what type of procedure we're doing then we're going to rinse for the same amount of time what I like to do before I hit it with the water is put my hve over that edge and suck it up first the last thing you want to do is cause all of that phosphoric acid to rinse throughout the mouth and hit the gingiva so what's the best procedure would be to do is put your hve over that edge suck all of it up that you possibly can and then rinse for the same amount of time that you are edging the next thing that for here is drying so you're going to dry the tooth out real quick remember real fast you're not going to sit there and give it the blow dryer technique okay we don't want to desiccate the tooth next you're going to pass the doctor the bonding so it'll either be a Dappen dish of Prime and bond or it will just be one step' bond and you'll give them the roll micro brush they're going to scrub it inside that to throw good they will more than likely air in the bond so that way it goes all over the tooth nice and even your doctor might want you to use your air water tip to Eric's in it my suggestion is to hit the air outside of the mouth before you air send the bond in the mouth because if there's a little water trapped in that tip you'll have to start over from edging we don't want any water in the bond we have to keep this completely dry some doctors like you to just place your HPE tip over the tooth and that will help air send the bond once we've air send it we will light here on step 6 so the light care once it's been cured we will start placing composite in increments of three to four millimeters at a time so you will be holding the light curing agent and the composite and another instrument to start packing that composite down in and you'll be transferring these with the doctor back and forth as you fill the tooth so you'll give them the composite they'll place it into the tooth you'll give them an instrument they will compact it down into the tooth with the instrument and then you will cure it and you'll go back and forth composite instrument composite instrument you'll want a two by two in your hands so that we can help wipe the instrument off if there's any excess that's stuck to it while they're placing the composite once it's done we will check the filling with our articulating paper the doctor will go ahead and adjust it and create any enamel that's needed and they will be good to go the composite will be as hard as it's ever going to get when they leave that day this is an example of composite materials you have a couple bulk composite tubes on the left those ones are reusable so we would want to extrude the amount out that we need for the filling put it into the Dappen dish and then put that clean bulk to back where it goes it does not go in the patient's mouth the next thing you see in there is a shade guide and of course the composite gun on the right those little carpools are one-time use only I don't care if you don't use all of that composite you do not reuse a composite car pile on another patient hello posit is more the consistency of molasses where the other ones that we just saw are compactable or condensable composite it's a lot harder the flowable composite the doctors like to use when there's a lot of little pits and fissures in there and they want to fill it up and make it nice and smooth and then a lot of times they will switch to the condensable composite again we're going to go over a process for composite here so removing Terry's rinse the tooth make sure all debris is removed place the etchant for fifteen to thirty seconds rinse for fifteen to thirty to avoid drying the doctor is going to look for that frosty appearance on the tooth once it's been etched they will go through the bonding and then cure it composite and then of course polishing here is an example of a curing light they're really awesome things about our curing light nowadays is that they are cord free so they're battery-operated the bad thing is if you don't remember to put it on the charger the next day is going to be a lower russ because it's not going to work for you one thing to keep in mind is you do not stare at this light okay it will burn your retina it is a tungsten blue light and it's not something that you want to stare at the entire time make sure you have that little orange shield on there because you do need to look through that shield and make sure you're on the right tube and then immediately look away the light hearing is a high-intensity blue light source it's a combination of tungsten and halogen lighting system the size of the restoration is a factor in exposure time so that means the bigger the restoration the longer exposure time and shade is also a factor so if it's a darker shade it might take a little bit longer to cure here's an example of some polishing materials that we use depending on whether it's posterior-anterior or an arrant proximal polish we can use all of these listed here so this is what we would call a slow-speed latch and this is the mandrel this little metal piece these are all reusable this disc however is not so one-time use only a lot of times we'll be using this on our incisal edges and the doctor will be using these little points and cup to polish the tooth to make sure it's nice and smooth we don't want any food traps or anything that's going to catch the tongue and cause irritation these are also some polishing and finishing burs this is just an example of what your doctor may or may not use and below here in this picture of these molars and premolars you see a completed composite restoration the shade guide we use to match looks great you can't even tell that there's a restoration in this tooth they did a great job in the composite tub materials you'll also see two different types of matrix bands these matrix bands that you see on top are for molars and premolars so these are posterior this one's clear it's kind of hard to see but it's there these ones are pretty awesome because they're prefilled they are also disposable one-time use only this is plastic it's not metal like the top a layer you cannot sterilize this lower picture you see down here is called a mylar strip and this is used for anterior composite placement here's an example of a composite on number 30 which we would call an occlusal buckle we're going to take a minute to watch this video you [Music] posits video with the acid s 35% phosphoric acid being placed around the enamel cave of surface margins first and then continued details around the remaining Denton after that to allow a 15 second catch time on the enamel a 10 second time on the banter and then you rinse for approximately 15 to 20 seconds and be careful not to desiccate the tooth by over drawing it so I don't even show you that here but you disappeared dry it lightly and then this brush shows the application of the Prime and bonding agent in different videos I could show separate primer then separate bonds and then third hole option would be to eliminate this blue as step altogether if you're using a self esther a one step which would be itching priming and bombing all of this application little micro brush you can see how I'm adapting it to the inside of the prep there's several different sizes of micro brushes that you could consider it the prep is narrow and then you air send it or another way to think of it as an air evaporation little set just to let the priming agent get down to Sentinel tubules and then the life shield and then cure this if you're using separate primary you wouldn't hear that this is priming the adhesion step after that the next some officers use layer of flowable composite which I believe I'm showing here to act as a base or as a liner it's very important to use flow you don't have to much to really fill the prep and then I usually take an explorer just to prevent any air bubbles to line the whole bottom of the prep and then usually hear that again for at least 10 seconds but again of course manufacturer's instructions need to be followed there the next step then is to load the composite and go Campillo and all different philosophies here most restorative expert should say saying to vertical increments to have a buckle increment a lingual increment and then a separate central increment so here I'm showing you that we face along the lingual first and really thought the same motion as condensing it's more adapting it to the edges of the press into the Popo floor and then curing it for at least 20 seconds but that's another thing that's really manufacturer's specifications on the light some of them are five-second cures 20 seconds yours you can know the light you're using it and I second the Beast and you can see the consistency of this material is a little sticky which some people light and some people don't that's why there's chocolate and vanilla but that's all preference health build it is complete sometimes a gloved finger just really smooth off the cable service I would never want to condemn to that or truly show you that but that's kind of just an interesting little tip that you can take that kind of adapt to the table surface very well is try to recycle as much as you can here shirt again the never doesn't want to increment no matter how little the prep is usually let go for a while and the last increment unlike amount on the composite preps do not need to be overfilled we put enough in the composite mass in here so that we can make sure the cable services field and then I adapted again with a gloved finger and then the anatomical burnisher really helps here too to find some Anatomy some anatomical structures again unlike amount on this is kind of me is like a stencil brush you can see how you're pushing in and it really gives very doughy so I I try to just get a central fossa and make sure I wipe off the excess there's not going to go anywhere and wipe up the prep and then remove it with my finger the design this acorn burnished are really dense and makes them inclined claims at the same time it makes some fossa so you can see the marginal Ridge area there if you left that there you'd be finishing it later so the more you can do with an instrument at this point the better especially for a new access experience hands can fission the handpiece very easily but the more you work on this step the better it will be because I'll have less finishing to do so you just check occlusion close the margins and polish it you can see all the excess is coming off of the instrument you have to make sure it comes off the answers before you reapply factors too so a lot of work is done you need to watch the overhead lights and it's not going to step your top layer on you look then you ensure this final layer with the finishing and polishing steps which we'll show you in another video you you [Music] all right liners in basis there's many different types guys again try not to get too hung up on the names that we use because it really just depends on your doctor and what they like so we are going to know the process for each type when and why to use a liner a base a lot of times we will be using it one because the doctor has treatment planned it but to because it's a deep cavity preparation and it's close to the pulp this is always going to be placed before the permanent restoration you need to remember that because if the cavity goes in deep and the doctor is really close to the pulp chamber they want to put a liner in there to help rebuild any secondary dentin and also help restore that pulp and that way it doesn't have any infection in there and end up needing root canal treatment so the purpose is to provide Coupole protection and dental regeneration it's placed in a thin layer at the deepest point of the preparation it's going to protect the pupil tissue from irritation due to physical mechanical chemical and biological elements pupil irritant physical thermal changes hot to cold and the electrical energy that is going to irritate the pupil so when the doctor is in there removing any decay and they get in let's say it's a mechanical cost from a handpiece vibrations or traumatic occlusion anything like that could cause the pulp to be exposed or irritated any chemical caused from acidic materials reaching the pupil tissue the only time they're going to reach it is one if it's being prepared and the doctor is removing decay or two let's say they have a really big deep cavity and it's already been exposed because of that cavity any biological bacteria from saliva or caries that are present will be an irritant to the pupil as well example of dental liners and basis dye Cal is a temporary liner that we like to use it has calcium hydroxide in it this is a little older dental material we don't you that's as often anymore but it is something that you'll still see doctors like to use the calcium hydroxide to help regenerate secondary dentin IRM is very common as a sedative filling or possibly a temporary liner a lot of times when the patient is in pain and they need to be referred to and adonis we can place a temporary filling which is also called a sedative filling using IRM so depending on how we mix it whether we mix it root and it's very pasty and it's kind of gummy we can make it into a sedative filling or if we make it a little more runny we can use it as a liner IRM stands for intermediate restorative material it does have zinc oxide eugenol in it so that will help calm the pulp down and help with the sensitivity the eugenol is oil of clove which naturally helps the tooth calm down and not be as irritated and painful as it was Mr Bond is a more common one this is a permanent liner it does have a glass ionomer in it and if all of this can come in a paste catalyst and based form that could come powder liquid or in a new dual syringe which is what we see here so this is our newer one they come in a dual syringe where it has the base and catalyst in here you squeeze it out mix it up on your paper mixing pad with your spatula or they could come with pre mixing tips where it mixes it in the tip for you and you can put it straight into the tooth just depends on how your doctor likes to do that the glass ionomer that's inside of the vitter bond the victor bond is the name-brand the glass ionomer is the chemical in there it can be used under all kinds of restorations so it doesn't matter what type and it can be light here to speed the setting or can be allowed to set slowly on its own it is measured precisely and mixed on a paper mixing pad with a spatula this one for the glass ionomer helps regenerate or I'm sorry it helps its a florid releasing agent so it stops any recurrent decay so it's going to inhibit any recurrent decay and stop the caries from spreading these the decal is a lot older this is the one that we were just talking about the calcium hydroxide it does come in two separate tubes like this and it is your basic catalyst you want to have equal proportions and mix them together on a paper mixing pad depending on what your doctor likes they will train you on the type of liner that you will use and they'll also train you on how they want it placed in the mouth some doctors like to use the perio probe after it's mixed and some likes to use a certain type of micro brush so it really just depends on your doctor again take notes guys keep it in your little lab coat so that way you know what to set up for the doctor when they're ready all right let's review impressions we have several different impressions to talk about it just really depends on what type of restorative material we're doing here classifications so preliminary final and occlusal occlusal is a bite registration and we do that whenever we have we have any like let's say we have more than one crown that we're doing abridge possibly night guard or a denture we want to get a bite registration on so preliminary preliminary impression can be used for a diagnostic cast which is usually what we used for study model we also take preliminary impressions for custom trays provisional coverage which is a temporary crown or a bridge you guys will learn in week seven how to make a temporary crown and you will also talk about in more detail what provisional coverage is which again just means a temporary crown orthodontic appliances we take preliminary impressions for and also I need pre and post-treatment record your final impression is more often taken by the dentist it's going to be used to take the most accurate reproduction of the teeth and surrounding tissue once the final impression is taken we will be sending it to the lab to fabricate a permanent restoration so the final impression will be taken of the teeth and the surrounding tissue so if we're doing a crown prep or let's say a denture or a bridge or an implant all of those different types of restorations will need a final impression that will be sent to the lab so they can fabricate that permanent restoration your bite registration is taken to produce a reproduction of the occlusal relationship of your maxillary and mandibular teeth so they want to know how the teeth come together and this is going to help them figure out how high to build that crown or implants or bridge we're going to show them exactly how the T's come together that way it will fit in the mouth when we get it back impression trays these are used to hold impression material within the mouth they come stock which is like your small medium large and they also can come in custom trays and that is one of the preliminary impressions that we can take food take a preliminary impression send it to the lab the lab would make a custom tray for us and then we would take our final impression with the custom tray when using a stock tray they are manufactured in quadrants sections and full arches there's many sizes and shapes so you want to find the appropriate size for each individual patient depending on comfort they need to be slightly beyond the facial surface of the teeth so we don't want it to scrape down on the teeth when we seat it in the mouth you want to be careful so it has to be big enough to fit around the teeth that way it doesn't scrape it and it needs to extend two to three millimeters past the last molar or tuberosity whether we're on the mandibular or the maxillary and the depth needs to allow one to two millimeters of material between the incisal edges of the tray so that means we are not going to let them bite down into this tray we don't want to push it so hard that it hits the tray we need to have at least one two millimeters of material between the teeth and the tray stock trays can come prepper ate it with holes or smooth with no holes the pro aided one does create a mechanical lock which is nice especially when using alginate because alginate is a lot softer material and we really want it to lock into that tray so it doesn't distort when we're taking it out of the mouth we don't want the material to stay in the mouth and the tray to come out by itself if you're using a smooth tray that doesn't have any hole there is no mechanical lock so you will need to use adhesive make sure you've already tried the tray in the patient's mouth please do not paint the adhesive onto the tray and then put it in the patient's mouth not a good idea right custom trays these are made to fit the mouth of a specific patient so that means we've taken a preliminary impression the lab has created this custom tray for us and now that we have a really nice custom tray we're going to take our final impression so that way we can get that sent to the lab and they can continue on with the final restorative material that we need you always want to use adhesive on these custom trays they usually don't have holes in them to create that mechanical lock we are using alginate which is an irreversible hydrocolloid the alginate is contains potassium which is derived from seaweed and used as a thickening agent the calcium sulfate reacts with potassium to form the gel and the trisodium phosphate will slow down the reaction time for mixing all of these are different so you want to go by the manufacturers direction some of them could be regular set some of them can be fast set that means you need to mix it quickly and get it in that patient smell the diatomaceous is earth zinc which is a filler to add bulk and the potassium titanium fluoride comes to play with the model-making so what that means is once it's set and we go to pour our our stone in it's not going to mix with alginate and ruin our model so we can create that model once the impression is taken and so a little more on alginate impressions to us are going to need your alginate powder your water measure a spatula and of course a rubber mixing bowl if you're using a spatula especially if you're using a metal spatula make sure that you've cleaned it off immediately when you're done mixing don't put the spatula down dirty and then go and take the impression so when you come back and it's hardens on that spatula it's really hard to get it off later we always want to educate our patients whenever we're doing any sort of restorative treatment or impressions please educate them and explain what's going on you're probably going to get them to cooperate a lot easier if you educate them and let them know what's happening so always explain to the patient what's going to happen don't lie to them you know let them know this is a good it tastes very good it might make you gag you know just let them know your material is cool it's going to set fairly quickly tell the patient to breathe in and out of their nose and wiggle their toes for distraction so we always want to use any sort of distraction everyone always asks us why do you start talking to me when you put something in my mouth you know I can't respond well we don't expect you to respond we want you to focus on the fact that we're asking you questions when you can't respond because it's a distraction technique we don't want you to focus on the fact that you want to puke right now because your mouth is full of an alginate impression rate or you're gagging so you want to talk to them in a calming voice okay we're going to take an impression on the lower or the upper you know whichever one it is I'm going to need you to lean forward breathe through your nose and this will be over as you know pretty quickly and just let them know and talk to them throughout so do you have any plans for the summer you know I hear it's going to be a nice summer this year or you know are your kids graduating from school you know just asking personal questions that you already know about them to try and distract them it's always best to start on the lower impression and then move to the upper the lower impression is less likely to cause the patient to gag so if you start on the mandible you can get that one out of the way before you start on the upper and trigger that gag reflex and then everything else you do for the rest of the day they're going to want to gag when you touch their mouth so try to start on the lower first and then move to the upper so this is telling you after mixing the alginate and loading the fairtrade is brought to the patient one hand will retract the lip while the other hand inserts the tray it is really important that you guys get that list over and around the tray and out of the way otherwise it's going to ruin your impression and you will have to start over so after seeing the tray over the teeth it is important to make sure that the lip is on the outside of the tray as shown here and not pushed up by the top edge for lower impressions is helpful to ask the patient to lift up your tongue so that the tongue will not be on so that the tongue will be on top of the tray after it's seated over the teeth I usually tell my patients when I'm taking a lower lift your tongue up wiggle side to side and relax so it will pull the floor of the mouth up and out of the way and it will help the alginate kind of seep in there it's always nice as well if you can get a piece a little bit of the alginate on your finger when you're doing a maxillary rub it across eight nine and then go ahead and push your tray in that will help capture that tissue attachment there on the left freedom that we often miss because the patient is either opening too big so you want to ask them to relax their facial muscles so you can get that lip up and over the tray impression evaluation please do not let your patient leave before you have evaluated the impression and gotten the approval from your doctor that it's okay when you go back you're like oh my gosh I already dismissed a patient I got to chase them down get another in question right so make sure you evaluate it take it to the doctor have them look at it in case we need to read and press the trace should be centered over the central and lateral incisors your peripheral role needs to be present so when you're trying to do that a lot of our dental assistants will take impressions from behind the patient and hold it with both hands or you could do it from the front everyone's going to do it a little different the tray cannot be visible through the material so we don't want to push the tray too far into the tea on the incisal or the facial or buccal surfaces we need it we can't have any tears or voids so avoid would be a bubble the mandibular retromolar area and lingual frenum in tongue C need to be present and the palate and tuberosities are recorded for the maxillary there's a couple different elastomeric materials for impression taking we just talked about alginate this type of material however is usually used for final impressions we will use a light medium or heavy body it is self caring so that means when we put it into the mouth we usually wait a good four minutes for it to set it is rubber based and it is it does have a catalyst and base material that's going to be mixed when you're done taking impressions it's important to follow OSHA rules for infection control so you always want to be sure to practice safety right by doing so you will be spraying your impressions with any type of disinfectant that you use to clean the room or you could submerge it in your disinfectant either way the impression needs to be disinfected before it goes to the lab whether that's our lab in the office or a lab that we're mailing it to we want it to be clean and ready to go the stone is what we use to pour up a model of the impression so a form of gypsum most common is yellow stone and it is used when a more durable diagnostic cast is required there's also buff stone plaster and high-strength stone that's the die stone that they use in the lab to pour up our models for our restorative material this is an example of the lab and what it will look like when you're pouring up your model notice how this person is not wearing gloves that's because in the lab setting it should always be considered clean this is a clean area we've disinfected the impression I always wear gloves because the yellow stone dries out my skin but I want you to understand why this person is not wearing gloves in this picture is because this is considered a clean area we shouldn't have to worry about any sort of infection control past being in the lab so the yellow stone is added in small increments to the impression and vibrated until the teeth imprints are completely covered so that machinery underneath his impression that he's holding is a vibrator it's going to vibrate all those little bubbles out once the teeth are covered and the bubbles are vibrated out then the plaster or yellow stone can be added in larger amount once your model has hardened and dried we will pop it out of the tray we're more than likely throw the tray away as long as it's disposable if it's a metal tray we'll clean it and realize it on the model you want to hold it with both hands flat on the surface when trimming it because you don't want it to go flying out of your hand it's important that you have your eyewear on and at least a lab coat because more than likely going to spray back at you once we make made our whitening trays we will give you post-operative instructions so we want we want to let you know that everyone's going to get different results because not everyone has the same shade of teeth not only that but some of us have restorations in our mouth restorations do not bleach so if you have a filling or a crown you need to know now that they will not bleach you always want to take a shade match of the patient's teeth and record it in the patient's chart before the patient takes on the trays so you can compare the difference make sure when you're doing those shade matches for composite material or for the bleaching you always want to do it in natural lighting so take them to the window hold up a mirror and let them help you choose a shade you're going to give the patient post-op instructions so only bleach the facial of the tooth place the bleach in a tray to the smile line if they put bleach in the entire tray it's okay but it is kind of a waste because more than likely if it's not their smile line we won't see those back teeth this can cause sensitivity what happens is it opens a tubules of the teeth to extract that stain and anytime they're open and you breathe or you drink or eat anything hot or cold it goes straight through and irritates the nerve so that's why that sensitivity happens so you want to stay away from soda coffee red wine or eating any foods that may stain the teeth during bleaching make sure you brush and floss thoroughly before bleaching you want to rinse the mouth within the trays with water and set the trays on a paper towel to air dry if you want you can use a fluoride rinse afterwards to help with sensitivity it is not permanent there will not be a permanent sensitivity from bleaching this is a couple pictures of what it looks like to create the bleach trays so we have our suck down machine here which is what you guys will use once your model has been trimmed we will heat this up and then once it starts to droop we'll push this down and turn the suction on and it will suck it down on to the tray here and then we will cut it out and then you have your pretty blue tray that's it before and after if you guys have any questions about week five or you need help with anything please reach out to your instructors we hope you guys have a great day