your first quiz siguro papaso kay Dr cat lang so the your quiz number one the cage will be the topic for this afternoon so that will be on September 6 Okay September 6 Okay so let's start okay no um if ever no If ever na There Will Be some problems with my ah audio medyo Static siya just inform me no o kaya naman later no Baka yung isang device ko ah nag-out do sa link just inform me no Baka kasi mamaya I'm just telling or I'm just discussing and then my presentation is not Uh reflected on your screen so just let me know if that will happen okay okay Ah so introduction to dental materials So it will includes a brief discussion about the history no the history of the some dental materials and yung kanilang ah properties of dental materials Okay so as an introduction no this Uh subject No when enable the dental health professions and also the students no to know the properties of the different dental materials and how to use them Okay and then to have a correct Selection when you say correct Selection This is about the proper um use no of the materials which is Uh indicated no for specific case and then manipulation of dental materials this is how you're going to mix no prepare prior to the use Uh prior to the use of material to the patient's mouth or kaya naman sa ah sa Cas or doon sa mismong procedure Okay so it's with largely determine the service of restoration that will give to the patient Okay so if you will know ' if you will know the Uh if you will know the kanilang properties let's say ' yung kanilang physical mechanical properties and then you know the limitations if it is brittle more brittle or kaya it has a high modulus of Uh elasticity or kaya stiff siya So it is Contra indicate or it is more Uh advisable to use no to the po posterior teeth no say supposed to it for the restoration If in case It will be used as restorative material no so again Uh another no this is Uh dental materials no deals with the basic science non that dos with the physical chemical and biological properties of dental materials when you say physical it um it includes the strength of the material okay and that also includes the mechanical biological is yung sa kanilang safety no safet has to use inside the patient's m or sa live patient Okay so as a part of history just like what you see on the picture no before we way back siguro ah how many years no siguro mga ah before Christ No there are already then this year is already ano um practice Okay so just like in this picture they use the natural tooth as the ponti no or artificial teeth to replace the missing ah teeth here so this is just like a fixed no denture wherein they use a wires which is made of gold Okay ah doc Wala po kayong Sorry po ay Wala ba Oh thank you for that share hindi Ayan sorry sorry Thank you for your ano for that reminder Okay so Sige ito naman sa History I will repeat this one na tayo sa definition for the history No just like what I mentioned No they use sometimes yung yung teeth that they're going to um shape it into a tooth like which is made of seashells Ivory Iyung tas no tas ng elephant and then bone and sometimes no the teeth of animals or humans This is to replace the missing tooth Okay just like on this picture they use this or This is made of natural tooth extracted natural tooth and then they use gold wires no to connect it to the other Uh remaining no remaining Uh teeth Okay so this is just like a fixed denture way before Okay so juning 70 to 800 bc Where in stw cans No they use partial dentures they begin to do partial dentures Just Like In this picture we say partial dentures only few teeth are missing no so It will be replaced either fixed denture Just Like In this picture or removable Okay so during 600 bc the mayans they Uh they start to do implants implants which is it can be made of Uh human teeth or Kaya minsan Iyung bone Okay and then inlay inlay this is for the restoration and others no in other Uh tribes no they also use yung mga pressure Stones no this will Uh serve as ornament sa kanilang teeth Okay so This is Uh how no deity is way back no before and then during 2,500 bc Where inf finans they use the gold wires and bands Okay This is to connect no the missing teeth or to connect the pontics together and then ah connect it with the other remaining teeth Okay and then during 3000 bc the Egyptian they are known as toth doctors No they will Uh they do extraction no But before medyo mas ano pa siya mas napaka tawag dito hindi pa ganon ka hightech no so they have a different Uh instrument to use the techniques no so it's started no during 3000 bc by The Egyptians so They called as tooth doctors no before you know yyung barber shop ' Ba yyung barber shop You will see there parang may mga types of colors no parang blue parang red white and blue okay before no in dentist in a ah Dental Clinic the colors only White and the white and blue so that will Uh that will be the symbols or the signage no of Den before Okay so that was during 3000 bc Okay and then this one I know this is this Uh Okay this Uh person yung for Shard is not this is not the first time you hear this name okay for Shard so He is the father of modern dentistry kasi because of his Uh works No there are a lot of restorative materials that was published okay that was during his era so that was 1728 no so There Will Be published tees of restorative materials so that is where the amalgam is already introduced Okay and then pa no during 175 they use wax no yung ah wax to do impression no to make plaster models so during 756 that is the material Where in Puff used to create impressions in the patient's mouth it is made of Wax and then during 1792 siaman they patented the minal tast Okay And during 17 1800s No they started to use the porcelain no as in as materials for inlay So inlay this is a restoration Where It only um the Store no Ah ano the center part or doon sa pinaka occlusal part of the to Okay And during 185 by J black he pioneered the rest mater restorative dentist 3 for he and he is the proponent no yung gv classifications no of cies no iung class 1 class two class 3 and class 4 and five so that ah that is the work of green varden Man black Okay And during 1915 they found out that fluoride no Uh the effect of fluoride in Colorado okay so there is when they check no It helps to make the teth mo less Uh susceptible to car formation Okay and then Denis so they started during 19 1919 they start to use yyung Amal gab for the US government so they they set Uh some standards no for the use of Amal gum and during 192 we in Dr sounder no He was absorbed by the Ada American datal Association because of his Uh excellent work no in the field of dentistry so together with his colleagues they Uh they produce no several researches in dentist 3 Okay And during 1935 yyung polymerized acrylic resin Just Like In this picture they used this one they start to use this one during 19 19 35 and then during 1944 they started to do florid okay so they added fluide doon sa water source sa water no supply so usually 1 ppm 1 parts per million so It Started during 1944 Okay so that will be the ano brief history no of some of the materials in dentistry okay so question No what is the importance of studying this subject Okay so These are the reasons first is for the knowledge to make optimal Selection of materials Okay so this will help you to know no Ano ba yyung gagamitin kong materials Para saan ba iyon If Ever I have this case What will be the material of Choice that I'm going to use okay Is it is it an indicated for the case that I'm going to do okay and then for number two to understand the behavior of materials use handling and manipulation so when you're going to when you know no What material are going to use you need to know the behavior when you're going to manipulate it Kailangan ba siya it needs to be subjected to heat to make it soften or kailangan lang siyang iano ah i-mix using ah instruments no Kasi for example no for for your activity number four yung modeling compound So we're going to use that one at first It's solid So you need to soften it with the use of hot water water but kaya naman sa Flame okay but water but ang gagamitin niyo so when you're going to observe that you will see no parang it will soften when it is subjected to increase in temperature Okay and then for safety considerations of the materials Okay so Uh Is it safe to use inside the patient's mouth Okay so if ever there are patients who are allergic to the composition of the materials no let's say Kari allergic sila sa ah usually Iyung cements that are Uh cements that have vinal content So you will not use that one kasi sometimes no patients have an allergic no to the composition to some of the compositions no of the dental materials Okay and then patient's Education So if you will know let's say Uh during impression taking No you're going to to capture no the dentition of the patient So you will use impression materials So if you will know that it will Harden after let's say after 1 minute So you're going to educate your patients no how they going to What will be their position during the procedure and what to expect no once you're going to place inside their mouth Okay so you can educate your patient no if you know the behavior of the material no and how to use it and yyung composition you will also you can educate your patient no what to expect and then what will be Uh How will the procedure will be ano ah conducted Okay and then number five understanding the professional literature Okay so here you're going to decide let's say ag you have restorative material Okay ah rest I Sorry restorative Uh subjects noo pag sa higher year so you will know no if if they going to talk about Um what El this one aesthetic no aesthetic restoration So it is Uh it refers to the natural Uh looking no restoration so mga compos it and then if it is non esthetic restoration that it will includes yung mga amalgam no so There Will Be terms that are used during the let's say mga seminars or in your different subject in dentists you will have an idea What is that no all about Okay so there are this is just some importance of studying No Why you why you need to study dental materials Okay so it has no two main benefits for the selection of materials and evaluation of the materials Okay so you're going to select first and then once you will use that one no we will evaluate it based on its strength yungang physical and mechanical characteristics okay when you're going to select This is the this will be the guide no so as a dentist or clinical clinicians So what will be the case They're going to select What dental materials based on physical properties biological properties applications and performance if the patient will come to their clinic and then who wants to restore their front tiit or let's say to number one one Okay so if you will be the clinicians or The Dentist in the future So the clinical requirements is doring the fractured too Okay so you're going to select What dental material are you going to use okay if it is on the anterior So it needs more it needs to be more natural looking no ung esthetic niya So you're going to choose when it comes to physical properties no dapat it can withstand no usually yung masticatory Force hindi siya mabilis magge Okay biological properties is it sav to use it inside the patient's mouth and applications how you going to use it okay What other requirements or what other instruments are you going to use during the procedure Okay and then for the performance no Ah yung last how Yung kanyang long long longevity Okay of the material Okay parang it can Ano ba siya it has limitations ba or when it comes to its color does it Fate or kaya magis ba siya if the patients have this type of um kanilang ano kanilang yung kanilang um diet if they love to drink coffees if it is Uh synthetic So it is more prone to discoloration Later on Okay so This is the importance No Why you need to select the materials for the evaluation so most manufacturers of dental materials operate extensive quality assurance so Before It will be available in the market no so there are several stages Where It is inspected Okay so There Will Be standard specifications love evaluation wherein it is needs to be tested into animal and then it will undergo clinical trials so once this things will be Uh done No that's the time it will be released in the market okay for the standard standard no specifications These are the different organizations no so Ada American dental Association and FDA federation ental Association so Uh all no all the dental materials no will be expected here and ISO This is international standard organization it is not only confined to deny but in other Uh products no okay for the Laboratory evaluation so initially They're going to test the new material Okay so It will be used during evaluation la Uh evaluation they going to use Um yung mga guine Pigs No they going to try in na guine Pigs or kaya sa different animals and they going to evaluate no if it has toxic effect no to the body no so usually they going to test a monkey or guine Pig So if they will find out that it has no Uh no toxicity And it will pass the standard So that's the time we're going to undergo it to some clinical trial so usually it takes 10 years No It takes How many years to make it to Pass this clinical trials Okay so manufacturers carry out extensive clinical trial of new materials in group of people so usually once it is already passed siguro sa sa laboratory They're going to select a population Okay usually in the university or hospital department before PR before releasing the product no to the ah taago to the market Okay so it will takes no several years Before It will be Delas sa ah market Okay so dental materials it may be classified into three So it can be preventive dental materials just stive dental materials and auxiliary dental materials Okay so when you say preventive dental materials no These are the materials that are used to prevent Disease in the oral cavity Here are the examples no so sample lang no a newly erupted no teeth permanent teeth usually so to avoid no usually to lessen the the chance of entrapment of foods doon sa mga pits and fissures and you will know na iyung pits and fuses na Iyun These are the areas that hard to clean So you're going to seal those areas and then by sealing that one So it will prevent the haring of bacterias on the those on those Uh areas no para there will be less chance of formation ng cavity or ng caries Okay and then some liners Uh cements no so usually they Uh release fluoride Okay so this will make no the nml No Less susceptible to caris attack okay or to acid attack Okay and then chemotherapeutic a like fes No M washes and cavity varnish so usually yung mga toothpaste it has Uh fluoride fluoride Uh content mouth washes antibacterial and then cavity varnish it has also fluoride Okay so by preventing preventing the tooth from um from developing caries no So it will serve as PR this are the material that will prevent no the teeth or prevention to develop no oral diseases to an individual Okay and then also chlorhexidine and other therapeutic Agents So it inhibit the progression of tooth Decay so remember yung preventive dental materials no this will make sure that there will be no or less yyung chance of developing ah oral non This this is in the oral cavity Okay so one is one Uh the most common will be caries Okay so so for the restorative dental materials this one There is already existing problem or let's say my caries na So you want to Ano to stop no the progression of the chies no so you need to restore you need to restore the tooth or replace the tooth structure so example if there will be fractured tooth or my caries These are the materials No that is used to restore the tooth no to F the tooth so usually no yyung mga comers amalgam and then compos it this are the materials that are used not to restore the the fracture tooth or the Uh the tooth that has carage Which does not involve ng tawag nito ng may PP No there will be no PP involvement if if that will happens naman no There is already deep cavity There are some tooth no Uh pulp protection which includes the liners and bases Okay so It will be It will be placed prior to this materials your Amal gum or composite and gas materials naman If ever na There is already Ah yung structures of the tooth ung majority of that already missing or compromise na it will can be restored with cast metals no usually it it is common to mga Ped patients Okay kasi usually mga front teeth ba So sometimes because of the baby battle Syndrome no yung they still drinking milk with using the bottle no milk bottle So what happens nagkakaroon ng caries yung kanilang Anat so to make it to save it no Kasi There Will Be A lot of Uh yung part of the an tee already destroyed or kaya nagkaroon ng fracture So yung iba No they put cast metals on it okay so it will restore no or replace the tooth structure so These are the materials no that are under restorative dental materials and we have two pala we have direct restorative materials and indirect the difference between this two is first when you say direct No it is used intra orally so usually No when you're going to Uh feat the patient you're going to restore it intra orally fabricate restoration or prosthesis directly no on the tip So it is done inside the patient's mouth when you say direct restorative materials you can use that one no directly inside the patient's mouth when you say indirect restorative materials These are the materials that are used to replace missing teeth outside the patient's mouth Okay so sa C do sa mga models or replicas of the teeth That's where the this materials are used no so example will be yung mga jacket crown no jacket crowns in lace on lace no na ind So this yung mga materials na iyon that are used to restore the tooth outside the patient's mouth or extra orally they will fall doon sa indirect restorative materials Okay so for the auxiliary materials naman These are the material no for fabricating dental prosthesis okay ng restorations so they not become part of this restorations or mga prosthesis So it will just use no to achieve or to create restorations Okay example yyung acid etchant no acid et Shan This is to make the tooth surface or an tooth surface rough no so to make it more to increase the retention of the restoration that's compos it it is used but it will not be a part of the fire restoration another will be impression materials o yung mga ginagamit for impression taking so they are just used to create C So doon sa pinaka final prosthesis or final Uh model no C They are not part of that final restoration or final Uh C no so It is just used to create a c okay and other ah auxiliary ito pa ba dental waxes no dental waxes also and then yung mga finishing polishing abas receives no this is not Uh will be this will not be a part of the final restoration let's say yyung mga sa veneers or sa mga composite restoration this is just to make the restoration smooth and shiny Okay so this the term for it is auxiliary dental materials Okay Okay so there are different properties of of an ideal restorative materials Okay first it should be biocompatible so when we say biocompatible it should be safe No when you use it into the patient's mouth there should be no allergic reaction happen Okay and then Bond permanent to the tooth structure or bone okay and much natural appearance so so usually if it is needs High aesthetics no especially sa anterior tit So it means It means that there should be ah spot yung ano ag ah when you going to use it ins inside the patient's mouth or to restore no restore a fractured to it should be spotless Okay so it should not be visible to the other and other visible tissues Okay sample will be dener naman no that's the reason why it appears pink Yung kanyang denture Uh yung kanilang um base It's to simulate the color of the Jin Okay and then as much as possible exhibit properties similar to those to enamel and tissues yung hardness Okay so that they can withstand masticatory forces and then capable of initiating tissue repair or degeneration of missing or damag tissues example will be yung tissue repair will be If in case There Will Be A Uh dip cavity no so after removing it there are cements that are used as a p protection that example will be ah excuse for a back to this one so yyung last will be capable of initiating tissue repair so If in case There Will Be let's say nga just like what I mentioned a while ago if there will be a de cardis and then it Ah siguro ah it is siguro mga the thickness of thein is already compromised wherein it is nearly exposing the pulp so to initiate a formation no stimulate the formation of Uh dentin on that area so There Will Be power protection or Liner No that will be used to initiate the regeneration of dentin on that part of Ah linin okay so there are different categories of bi materials So it can be sa subdivided into five no and yung pinaka yung is the composite no to this classification polymers metal ceramics and natural So yung pinaka fifth classification is composing So this is the commonly no yung to restore Uh tooth no Which has the same Shade of a natural to okay now no let's proceed to the properties of dental materials Okay so here you will know no you will understand the different physical electrical and mechanical properties of the dental materials Okay so it is also important in the selection of materials to have a knowledge of their effect the tissues and possible toxic effect if they are ingested Okay so properties of dental materials before mixing so un mix So by the way in this picture This is sample of gypsum product Okay so before mixing and mix state there is mix of let's say if it is a powder and the liquid and then mixing It's still like a viscous ung kanyang consistency o thick consistency Then after setting It will be It will be Harden So from being a powder in form so when it mix with water There Will Be what call this one A thick solution a thick consistency and then when it reach no Yung kanyang setting time So it will become solid or Harden ah material Okay so before mixing during un miix So it will include the shelf life Okay When You Say shelf Life This is the length of the time no of a dental mater that can be stored without deterioration so It's very important no Kasi sometimes there are there are materials that even it not get expired but if the storage no or The Way It is Skip No it's not It's not properly k So it affects the ano the quality of the materials may mga ganon when you're going to purchase minsan hindi pa siya expired pero pag minix mo it's already hard din pag mabilis siyang ano mag-set Okay so it should be Uh properly placed with our Uh into tight se usually yung mga gypsum products no or other materials it should not be plac in a taago y sa mga extreme no in aas with extreme temperatures dapat usually dry and Yung kanyang humidity is at least and must be stored as per manufactur instructions soab it should be Keep in a dried place you need to place the materials on that area okay and over storage should be avoided no so Hwag yung iba kasi bumibili na napakadami so to avoid that no to happen kung ano lang mako-consider siguro for your Activity 1 M2 yung 1 kilo o kaya if you're going to use it for 5 and si yung plaster you can buy 2 kilos of plaster of pares Okay kasi storage of excess material if it is not properly kept no Siguro kahit hindi pa siya expired mabilis na siyang maeri hindi na maganda yung kanyang quality Okay during mixing setting so mixing time and working time setting time Okay for the mixing time Okay is recommended time no where in it differs the recommended time for mixing a material until reir consistency so There Will Be homogeneous mixture so in this example This is a castone no kung nakita niyo it has no more Uh yung mga powders no o kaya all powders are incorporated with liquid Okay so usually it is the time from the addition of powder to water and then there is a complete mix of water and then the powder Okay so when you check it no kanya homogeneous ang kanyang consistency and walang mga lamps okay for the working time This is the time During which material can be mixed or manipulated ideally with no thickening effect Okay In short after mix it no this is the time where and you can still load doon sa sa sa mold o kaya sa impression So it can still flow Okay so time available to use a workable mix Okay kasi After this one after the working time no it will start to hard din so usually pag hinal mo siya on that particular material una after mixing the powder and then liquid medyo It's easy to Ano to to mix and then one once it will starts to Uh Harden No you will you will see na it can no longer for on the impressions These are the impressions no These are the cast Okay this is for the edentulous arch and then this is for the dental dental means it has a presence of teeth Okay so this is for Uh This is the required for a material to reach a certain level of rigidity elasticity Okay so impression No there are some impressions that when they reach their setting time they will become hardened or others naman it will become Uh let's sayung ano flexible okay and this is the starts when the mixing begins until the material hardens so setting reactions complete is complete So this time sa setting time you can no longer use it no to for if it is a gypsum product doon sa sa m kasi it will not Fill the space kasi nga it's already thicken masyado na siyang viscous So it will not flow Okay magkakaroon siya ng mga bubbles if it is on the impressions Okay after setting this are the different properties naman okay so you have the biological properties chemical properties electrical properties thermal properties physical and mechanical properties I'm going to discuss this to you no in detail Okay First for the biological okay for the biological properties this includes no yyung mga material should not be toxic no or not not irritant or allergic to the patient's mouth example no no if you're going to use just like what I shown to you in the previous Uh slide no yung impression dapat it will not Uh ano it will not um bring any Harm No if you're going to place inside the patient's mouth unless na lang Iyung patient niyo talaga is allergic to the composition No but if it is in a normal normal ano normal ah normal ah healthy no normal patient no so pag ginamit nio siya it should not give any allergic reaction no to the tissues or doon sa patients Okay so primarily the dental materials must be harmless no To manufacturer both no to the operator to the assistant no to the patient or any person do doon sa work ah working area operatory area Okay so they should be compatible so for example the property being non destructive to biological system So here no so these are made of composite restorations Actually Amal gum Amal gum and other porcel so when it is placed inside the patient's m they should not be any harm okay yung Amal gum naman kasi ah it is not Uh toxic No when it is yung Mercury Mercury kasi Iyung toxic So if it is mixed with other metal no So it not it will not bring any harm even if it has a Silver feelings no inside the patient's Mou so biocompatibility is defined as ability of material to elicit appropriate biological response in a given application the body so they should not bring yung mga ah soreness no or any um allergic reaction no pag ginamit sa ano inside the patient's mouth okay for the chemical properties so These are the different chemical properties of dental materials we have absorption adsorption absorption diffusion of osmosis solubility erosions adhesion cohesion surface energy wetting contact angle of wetting in ling Okay so when we say sorption it is refer to adsorption and absorption so This is taking up and holding of one substance by another So it has to no pwede siyang adsorption absorption so the difference between this two is pag sinabing absorption we going to take There Will Be A yung pwedeng yung molecules will be penetrate doon sa solid material Just Like In this picture so It will be absorbed so the molecules will absorb by the solid material and then adsorption the molecules will be only lies on the surface no of the solid material Okay the process in which liquid or gas molecules adheres firmly to the surface of solid or liquid example no Iyung tooth no let's say tooth is the solid Iyung enamel non so the saliva will just stay doon sa surface of the enamel so that is example of adsorption Okay another Ah yung other examples naman will be if we going to place cotton no in the patient's mouth and then the cotton will absorb the saliva that is absorption Okay so that is the difference between this two Okay so when you going to say absorption it differs to adsorption and absorption Okay absorption intake no if there will be uptake of uptake of the molecules absorb adsorption doon lang siya relies on the the surface no of a solid or liquid Okay this two I know this is not new to you You already heard this Uh terms no sa I think sa chemist diffusion and osmosis when say diffusion this needs energy no kinetic energy of Random motion Kasi this is the movement of solute from low high concentration to low concentration Okay there should be an energy so There Will Be movement of solution of solute no solute yung ah pink so It will be go to a low concentration so diffusion Okay sorry this needs does not need ano does not need the energy for the diffusion kasi it High from High concentration to low concentration So this is the movement of solute sinabing diffusion okay pag osmosis naman This is the diffusion of solute From This is the movement of solvent solvent from low concentration to high concentration that's why it needs no Uh energy Okay so there areo there are some Uh experiments no for this one if way back sa inyong ano sa inyong ah chemistry no yung pasas yung facings no so there are there will be experiment wherein this two will be observe no So if you're going to no Iyung Um yung solution which is may with salt and without s o kaya naman After you will wash Uh the dishes no kita niyo ung hands niyo it will become wrinkled It's because of this Okay of this Uh properties sa materials naman in dentist No it will also happen o so siguro ag if you're going to mix the what this one the magagawa ung amalgam Okay let's see in other ano Uh in other experiments nonno Where in this two will be ano Uh observed no diffusion and osmosis Okay next is solubility for the solubility this is how will the How will be the one material no will dissolve in a fluid No just like in a saliva or water Okay there are materials let's say ung mga mga dental cements no dental cements used to um to fix or to Uh to fix the yung mga jacket crowns no and also for temporary restoration mga cements these are soluble to oral flu when you say soluble they can be dissolved no by saliva no So if that will happen What is the clinical significance So if it is prone to Uh to dis sol inside the patient's Mou so meaning there is a Chance of leak micro leakage okay if there will micro leakage so There Will Be in and out of liquid or saliva in between the restoration and the tooth and then if has bacteria on it so There Will Be formation of secondary cars Okay so solubility no solubility so again sample of that is dental cements they are soluble to oral fluid They only differ with the percentage of solubility okay but most of this or all the deta cements are soluble to oral fluid Okay another will be When you're going to mix non when you're going to mix the gypsum product for your Activity One and Two they are soluble to water so we going to mix water in Uh powder of your gson product or plaster with the water no They're going to combine because the water no will dissolve the powder of the gypsum products next will be the erosion Okay so erosion This is the process wherein there is Destruction Destruction of the natural teeth because of acid attack or chemical Okay so as you see in this pi Sure no there is erosion because of the reason of this one is the patients is love or fond of drinking or eating sar foods or acidic so There Will Be A the solution no the solution or Destruction of the enamel kasi enamel is the hardest tissue in the body and it can be only destroyed by acid no so usually yung iba they love to drink they love to eat citrus food o kaya naman love to when they going to eat no may vinegar lagi so There Will Be erosion that will happen So this will be Destruction of the natural tooth because of chemical attack Okay so Destruction of natural heart tissues by acid So it will happens if there is a patience is love to drink yung mga sarf o maaasim mahilig sa Maasim So you will see no magiging shiny yung surface and others naman No they have a systemic dis ah they have the eating disorders No not not systemic disease eating disorder no yung mga may bulimia nerbyosa parang feeling nila when they going to eat no Parang konti lang kinakain nila pero parang feeling Busog na busog sila so they tend to vomit no So it has an acid so usually no naggiging Ano ito shiny nag-e-emo Okay another will be adhesion And cohesion so what is the difference between adhesion and cohesion Okay so it pertains to the attraction of molecules so they they only differ when you say adhesion there is attraction of molecules of different substance just like on this picture no this will be combined no ung paper and then ah tape no so There Will Be adhesion and then sa cohesion naman molecules attract each other wherein here there are two circles or drops of Mercury and then if They're going to be Uh combined They're going to have a large the same same material and then they will going to increase the size example sa adhesion iyung denture ' ba Iyung denture if the patient has no longer Presence There's no more teeth inside the patient's mouth How will the denture will retain no doon sa patient's mouth It's because of this one no So yung saliva no saliva will adhere because of the sal saliva no so magad siya nila doon sa sa surface of the of the denture no so magstick together so that it will be hold saliva will will be in between the the anatomical landmarks no doon sa supporting tissues inside the patient's mouth and then the one the denture so It will be hold together so that will be adhesion okay for the cohesion There Will Be union of same molecules just like on the picture yung amalgam if you're going to combine it No they will just Uh form no same material but they were going to increase in size Okay so adhesion cohesion attraction of molecules so They only differ pag same cohesion pag different molecules adhesion Okay surface energy in surface tension Okay so yung surface energy the increase in energy per unit no is called a surface energy or surface tension so for example No there is inter Uh interfacial tension No that will exist between the two surface due to unbalanced intermolecular forces okay for the adhesion to exist the surface must be attracted to one another at their interface so example diyan is again denture no so for the denture to be adhere non doon sa sa palet o kaya doon sa tissue no inside the patient's Mou it should be have a less no surface ah tension Okay so for example ah low sorry it should be High surface energy no so low surface energy so non wetting example niyan is yyung consistency of the saliva of the patient No there are patient yung kanilang consistency of saliva is para silang thick no thick Yung kanyang ang kanilang ah saliva so the tendency is it There Will Be sticky sticky in between sticky saliva in between the ah ah the denture and then the surface doon sa mucus of doon sa sa tissue side of the patient's mouth sa tissue side no so There Will Be A Chance na malaki Iyung gap in between so the tendency that Then she will fall okay but if no if the consistency of the the consistency of the saliva medyo watery so There Will Be a good wet ability and then There Will Be adhesion mas magiging retentive Iyung denture Okay so that is the importance of knowing this p if we're going to correlate it into a s denture no how it will be become stable or become retentive sa patient's mouth even if there's no more tee that that are present Okay so so pag low ung surface energy there be no wetting meaning masyadong ah less yung saliva production dry mouth Iyung patient at the same time Kung meron man Uh inadequate um flow of saliva and then medyo thick Iyung consistency so tendency non mahuhulog iung Venture but if there will be good saliva production no or yung flow and then thin yung consistency There Will Be retention of the Okay so that Uh will explain this one for adhesion to exist the surface must be attracted to one another at their interface mas maliit yung gap mas retentive siya okay wetting and wet ability Okay so interfacial tension between a liquid and a solid disting in a contact angle of less than 90 de Okay so usually negligible when the surface molecules of two materials are separated by a distance greater than 7 nan soyo maliit siya if we cannot see it with our naked So if it is if it is more than more than 90 de it has for wetting but if it is less than less than 90 de it has good ability so There Will Be if we're going to correlate it with the retention of the prosthesis mas good okay and another will be you excuse Okay another will be yung ano ah if the powder no if it is ah has a good wet ability no property they can easily be mixed Okay so ang tawag do is it has compatibility or hydrophobic sila hydrophobic it loves water you're going to use water as your solution not to mix the powder So it is hydrop hydro philic Sorry hydrophilic no So if it is naman if you use water and combine it with other powder and then There Will Be no Union nagar sila So it will not be mixed no Uh properly Or will not be join iung powder and then the liquid and then it happens na it's not compatible they are hydro phobic okay okay for the contact angular wetting So this is the contact angle Okay and then the liquid drop If ever na This no this will if the molecules no of adhesive are attracted more to the molecules of surface the adhesive will spread completely over the over the surface of solid Ganito lang yan if it is if They're going to combine it has good weet ability the contact angle will be less Okay so magjo-join sila mas less yung angle na to No It means that it has good weet ability or good wetting okay but if it is high or 90 degrees or more than that no it has poor no for wettability Okay I hope you're still there Okay so for the electrical properties naman So yung kanina this is for the ah physical physical properties no ay sorry for the mechanical properties y this time is electrical properties of dental materials so we have conductor insulator electric conductivity and galvanising okay when say conductor no these are refers to the mater that the flow of electric current in one or more dire so example will be a metal wire it will conduct it will transfer yung flow of current or hit Okay so that we all know that metal is a good conductor for example if you're going to nl kayo ah Siguro before sa oral Allan niyo no if you're going to use a fire o kaya yung metal hand instrument niyo lagay niyo doon sa torch niyo o kaya doon sa alcohol lamp nio ba umiinit siya It's because it metal is a good conductor okay and yung insulator naman no this will resist the flow of the electric current so they usually refer as insulators so they will stop no stop the flow of the current or yung temperature no so example no if there will be a let's say amalgam this is an amalgam restoration it is made of metal no So if we going to use this one as restoration so there is a tendency na it will absorb heat or yung temperature let's say ng coffee So this is a metal It will be absorbed no magfo-four na to yung temperature so Might Be sensitivity no the patient will will feel so to avoid that no to avoid detrimental effect or um negative effect doon sa tooth noo there are pulk protection that will access insulator so It will be block yung transfer of heat no from the tooth Uh from the resolution to tooth directly by the use of this cements this will act as insulator Okay para hindi na magta-transfer hindi na-damage or There Will Be no irritation of the Okay so that is insulator next is electrical conductivity when we say electrical conductivity This is the ability of material to conduct electric current so electric conductivity for exle transfer of heat no from one metal to another Okay so usually it happens No when yyung galvanising it happens when there are two dissimilar metals inside the p which they are opposing remember no this phenomenon will happens There Will Be galvanic action if there will be two dissimilar metals that are in contact Okay so for example This is made of of alloy crown and this is gold so there are two these are made of two different metals so when the patient will bite Okay and then with the presence of saliva There Will Be para siyang nagano nagkakaroon ng ah electric no shock so there is a sensitivity or sharp pain When There is when the two different metals in inside the patient will be in contact Okay so that is galvanising so so the significance of knowing this if you're going to say tooth no ka- crown mo siya if you're going to replace it with metal restorations do not use two different metals to restore no the two opposing teeth kasi this might happen galvanising example naman kahit h naman gold crown ginamit ni sa lover but it it is made of amalgam still no still these are two different metals kung Al sa taas and then sa baba it will the patient will experi galvanic action or galvan magkakaroon ng sharp pain when two dissimilar metals will in contact Okay ah there is ano presence of saliva kasi it has an ions that is present no Okay so that will be the electrical prop and then for the thermal properties of dental materials this are the boiling point melting point freeing point DU point heit of fusion heit of vaporization thermal conductivity thermal diff specific heat and coefficient of thermal expansion Okay so boiling point so the temperature at Which I like a liquid no boils and Turns Into A vapor so usually no iung boiling point of water is 100 100° celsius Okay so for the boiling point if you're going to let's say boil Uh if you're going to compare the boiling point of a top water into a purified or distilled water no yung mas mabilis magbo Although they have the same boiling point no ung ano ung an distilled water kasi mas less Yung kanyang ah on residues no so for the melting point naman the temperature at which a given solid will melt Okay so for example non solid no which is let's say ice and then if you're going to leave it on the table non So it will become liquid so that is the melting point and then for the freezing point this will turn your liquid into a solid again so from water if you're going to place it into a sa fridge So it will turn into a ice so that will become a solid form Okay so boiling point So this will turns a liquid and will turn to the VAP or melting point from solid it will become liquid or it will melt freeing point it will from from liquid it will turn okay for the Jew point this refers as atmospheric temperature So it varies no When There is yung presence of according to pressure and humidity Okay so below which water DS begin to condense and Ju can form Okay example no a higher Jew point indicates more moisture in air kaya There Will Be more what sometimes no You will feel that parang malagkit It's because of the high humidity There are more presence of moisture no in the air Okay so kahit minsan par ang malagkit It's because of highw point okay so greater than 20 de Cel is considered uncomfortable minsan kahit malamig pero parang after let's say usually after pag umulan parang medyo maalin at malagit It's because of this one It's because of High humidity madaming presence of moisture in the air okay heat of fusion Okay heat of fusion this requires no to change a gram of substance from the solid to liquid seat at melting temperature so bo-o going to boil it to fuse or to unite no the materials just like yung Uh materials No that we going to use active number for yung modeling compound okay to make it no first to make it soften you need to subject into hit o kaya sa sa Flame o kaya sa water b and then to make it to make no the whole no the whole material to soften and then fuse make sure that all of that will be soften tapos iano siya you're going to need it so that it will be Uh consist ung will be the all throughout the material Okay so to fuse the material Okay kit of vation So this is the energy required to change a gram of liquid into gase state at the boiling point so will be heat of vaporization so there will beung water it will evaporate okay for thermal conductivity this will be the flow of heat to the material so example no if you're going to use if you're going to use metal metal tapos you're going to soften or to use it in your activity So if it is made of metal tap going to place over Flame expect mo non na when when you place it no longer doon sa Flame so the transfer of heat is faster because that is made of metal because that metal is a good conductor so thermal conductivity the flow of heat is faster okay but if it is made of Uh plastic no o kaya Ubod No there will be less ung kanyang flow of heat Kaya nga usually no yung yung iba if you're going to use yung metal spatula niyo it has a wood wood ung kanyang um this one wood ang kanyang Uh handle no so the tendency it you can still use that one without being ah tawag dito ito yung hurt no Kasi the heat transfer will stop only on up to the metal okay other will be if the material is made of resin plastic Okay so meaning No It takes more time no to subject the material to heat Before It will soften kasi nga to make it sure na magfi no Kasi let's say if this made of resin or plastic no the tendency Is You need to maass buong ano or you need to the material to make the to distribute the heat all throughout the material para maging even Yung kanyang p even pagiging soft Okay and then thermal diff This is substance divided by the product of density and specific heat capacity okay pag termal diff if it is yung thickness no if so the tendency yung thermal diff ni is mas the density of the if the density of the product is less Yung kanyang thermal deity is Higher Okay Gan lang siya okay So ano bang example here kuni if you're going to compare yung carvers tapos compare doon sa instruments na medo mas carvers car in ano in in ah oral alat ano if you're going to submerge it to hit both Tapos yung isa medyo maliit yung isa same ano same Uh same instruments Tapos yung isa lang is ah shorter and one is mas ano siya mas thicker and then mas longer so the one that will be get Uh will hit fast will be the smaller one kasi it has less ung kanyang thickness and short ang kanyang Ano ang kanyang um size Okay so sa thermal deity it affects yung flow of the heat when it when in terms of kanyang density yung kapal ng materia okay and also the type of the material if it is metal masil si diffuse yung heat and if it is synthetic or kaya plastic no mas less kasi for conductor ng ano four thermal conductor ang plastic okay for the specific heat No it differs to the amount of heat per unit mass required to raise the temperature by 1 de Cel so usually no ah if inside the patient's mouth normal is 37 de celsus unless Saang impatient No it has a say medical Problem no so 37° celsus Okay so Yung kanyang coefficient of thermal expansion say the patient will this is the restoration it is let's say this is um made of composite Okay which is synthetic So this is the patient will drink cold water So what will happen this is under coefficient of thermal expansion it will contract nag contract siya it will shrink in size so There Will Be space in between the restoration and then the tooth Okay so This is what will happen after naman o kaya naman opposite to this one the patient no this will the patient will it will um drink no hot water or kaya hot beverages the tendency it will expand Okay so it will expand so There Will Be protrusion or excessive material on the side Okay then afternoon it will it will cool down So it will no it will create a space in between so the clinical sign of knowing the coefficient of thermal expansion if it is the same with the natural toth if the toth will contract and have the same se Excuse me lct no the tendency is there will be no leak that will be created Okay pero no if let's say yung lct ng material is higher than the natural tooth the tendency There Will Be gap that will be made no So this gap in between the tooth and the restoration it is it will harbor no bacterias and then later No there will be if it is not be cleaned no Kasi nga There Will Be An ingas and inas of the fluid so there be formation of carries on this area okay so coefficient of thermal expansion There Will Be changing length per unit Regional length So it Where It will rise non depends on the temperature So this is lct or coefficient of thermal expansion Okay so ag hot water or kaya cold or decrease in temperature it will contract and if it is Higher temperature No it will um expand Okay so para siyang nagkakaroon ng contraction and then ah expansion so Nagkakaroon siya ng space Okay so that will lead to micr leakage okay for the physical okay for the optical we have the color u value Chroma transparency translucency opacity and fluorescence from radiological naman we have viscosity clip and flow visco elasticity Newton behavior plastic behavior trophic behavior and danta okay for the color this refers to different wavelengths no present in the beam of light determine the property of color So it defers to different colors no yung ah tawag ito neutral colors no so that is a color So it has properties no yung u value and Chroma pag youth This is important No when it comes to shade Selection Okay kasi sometimes No there are teeth that appears para siyang ma grayish or sometimes no Iba yyung color niya under a natural light and under the under the light of the dental chair Okay so you need to know this properties Different Properties okay pag sinabing u pagu this refers to the property associated the color of an object so It depends to red blue red green blue so and so forth so Aung u so these are colors Okay so P value pag value it refers to the darkness of the color So if it is red light red may Dark Red ba So it refers to the lightness and Darkness of the color Okay so that will be value and then for the Chroma degree of saturation of particular you so the higher the Chroma no the more intense the color so mas darker siya no so Chroma Ayan mas medyo mas darker siya mas intense ang color ng Ah mas mas intense magiging shade or color Okay so you this refers to the color value it differs the lightness and Darkness kung light ba siya or dark Okay and then for the intensity of the color it the first to Chroma Okay another will be transparency okay for the transparency This is the property of a mater that allows passage of light in such a matter that object may be clearly seen through so pag Saab transparency It will be reflect no let's say if you're going to restore no the tooth let's say sa anterior no if you fail no if you're going to fail to remove the the cies No that the cies inside so and if it is anterior so it can still see no doon sa pinaka outer surface of the restoration it can reflect okay So if there will be light that will pass so This is no let's say it will be what it's inside will be reflected no outside Okay so it can be clearly seen through translucency naman There are some properties of material that emits passage of light but disp the light so object canot be seen thoroughly so there are only some lights that can pass through Okay then opacity the property of mater that prevents Uh the passage of light so There Will Be no light that pass is through example no yung amalgam Okay amalgam Uh when you're going to check it when you're going to see it sa x-ray it Ces as radio of pak so meaning it is white and color and the reason why it's it's like that It's because it is Opa So it prevents the passage of light so iba-block niya no So yung light that can be pass or radiation cannot pass through doon sa sa an na iyon sa sa restoration of sa materials So that's why it appears as white okay and those areas naman that appears as um black no So this These are the areas wherein the light can pass through that's why they will appears as dark or dark no or black and the image sa Xray Okay fluorescence naman no this is the phenomenon of mission of light by substance that has absorb light or other electromagnetic radiation So this is the absorption of different radiations or light no so that it can be seen like this one Okay so substance that absorb light of Higher energy So it appears like this of different in different no shades of light so Usually sa ano to sa mga radio ah sa x-rays no next will be theological properties for the theological properties No it refers to the flow no flow and the formation of material okay when it is interrelation between force deformation and time Okay so it's also the study of manner In which materials is fond to apply stress or strain and the term no reos comes from the Greek word I mean the term theological it comes from the Greek word reos meaning flow okay pag geological the word that is ah can associated with with this one is reos meaning flow no flow of Uh ah flow or deformation of the material Okay so it can be divided no into two yung Fluids no this this is the flow of Fluids can be non newtonian and newtonian sa non-newtonian we have Rio stable so the plastic D lantan and bham and then for the newtonian which is non stable no we have tix atrophic in antix atrophic so On This example Okay we have the viscosity we say the viscosity This is the resistance of a liquid to flow okay usually it is dependent on interatomic bonding Okay example if you're going to compare of this is a let's say a water and then the Honey okay when you're going to Ano to Uh drop no to put a drop of water or Honey no sa table which do you think flows Uh faster is it the water or honey Ano kaya so obviously ang ma sticker diyan is Honey that's why ang last na mauubos will be the Honey Okay so what is the correlation of this picture to the viscosity yung viscosity kasi it means no mas mas thicker mas thicker yung consistency mas vis yung fluid Okay so less discus mas watery Yung kanyang consistency so water molecules has sweet interatomic bonding does flow easily as compared to oil and Honey Okay Iyung water kaya This is less viscose Okay so Iyung sa Honey It is a or viscose so the importance of knowing This is when when you're going to mix dental cements usually no so there are cements that appears as yung viscous nila viscosity example will be yung let's say eugenol mas less viscose siya if you're going to compare to um this one gic no GL ionomer cement Okay so there are different consistencies of the fluid or the solution that we're going to Uh mix no sa okay so basta p yung liquid will can easily flow or mas less resistant siya when it flows it has a less viscosity ag mas thicker siya mas thicker yung consistency and mas less mag flow sorry yung kanina sa water No it's easily to flow it has takes a lot of time or difficult to flow it it is more viscose Okay next will be CP and flow okay yung kanina viscosity This is the flow of fluid pagp and flow This is the flow of solid okay yung crip example will be this amalgam okay yung crip This is defined as the time dependent plain of Mat under Static load or con St when you say plastic strain no this is the deformation deformation of the restoration under Static load or constant str let's say kasi usually Iyung crip after the material will set that's what when the scrip will happen no pag kumagat si patient no and there will be load that will applied on this areas tapos this one It will be flow o magfa-franchise It is time dependent no and then pag flow naman this implies a greater deformation produce more rapidly with a smaller applied stress sa Clip mas higher yung stress yung load that will be applied kasi this one It's Al it happens No when the material is already set It's Harden pag flow naman hindi pa siya set Hindi pa siya nagen So a little amount of stress will be applied magform siya Okay so it has also greater Okay kasi it's not yet fully set or hardened Okay so flow describes the theology of the amorphous materials in pst no we say amorphous materials this are the materials that has no specific no ah shape no large in size next is visco elasticity visco elasticity naman This is in between in between the viscus state and elastic solid example will be elastomeric or rubber impression this one Okay so when you're going to mix it no medyo thick yung gyang consistency Okay When you try to place it inside this inside the mouth it will Harden And once it will Harden it will elastic siyang flexible when you're going to disengage it inside sa patient's mouth no para siyang ano It's like a rubber kaya It's visco elastic no so the more rapidly the mat is loaded or unloaded the more elastically the material will behave Okay so This is in between liquid no and elastic solid viscous liquid and elastic solid and the good example of that one is meric impression material or Rob impression okay for the another no we have the ba yyung fluid the flow of fluid you have newtonian and non newtonian for the newtonian no example of this one is water no When shear are when the shear strain rate is proportional to shear stress the behavior is neoni no newtonian behavior Okay S for example nga yun is the ah saliva one of the patient okay for pseudoplastic behavior naman the material is called pseudoplastic is because it's in between viscosity decreases with increase in share rate example yung mga cements when you're going to apply when you're going to mix it side pag stress This is the Uh force that will applied no Lateral There Will Be Lateral Lateral forces so pag minix niyo siya no it will become less viscose or less thick Yung kanyang consistency okay pag tiot trophic naman this are materials exhibit a different viscosity after the formation example yung ah there are impress yung mga impression materials they will not move they will not flow unless na lang There Will Be increase in pressure pressure doon o kaya ng Force Okay they will just flow if they will be increase in pressure or flow an pressure or force Okay example will be Z oxy yogen paste and for the dant This is the behavior in liquids that show higher viscosity with in sheer rate no example will be we going to make a Venture base pinest mo siya lalo No it will become more Uh tawag ito viscous Okay so I hope you're still there and you still with me no so These are the different terms No that ah you need to Ano you need to study no for your quiz ah on next Friday sa laboratory niyo okay for the mechanical properties we have the stress strain proportional limit yield point modulus of elasticity poison Uh ratio toughness brital strength and resilience hardness relax and permanent ductility and malleability Okay so defined by the law mechanics no usually physical science thats with energy and forces They they have an effects on the Bodies Okay so mechanical properties needs to be considered and it is intended for the application of material Uh which is important so the longevity of the material will depends on the mechanical properties of the dental materials that we going to use no in dentist 3 Okay failure or success potential of In prosthesis Or respiration will depend on the mechanical properties no agag masyadong inferior Yung kanyang mechanical properties it is more prone to fracture or dis sludge a dis lodgment due to after it will fracture Okay generally there are force that I will applied no usually yung xal When You Say xal this is compressive no so when you say compressive stress compressive Uh stress there will force that will push no together or There Will Be squeezing para siyang ini squeeze no so that will be compressive stress shearing naman There Will Be sliding paside Lateral movement or rubbing Okay so torsional This is the twisting movement Okay bending There Will Be movement of the restoration no movement not the restoration the anterior posterior Okay just like in this picture okay other force will be compressive shear strength and then ala ha tensile no tensile stress and 10 cell str ah 10 cil stress naman This is the material Will Be As if pulling no pulling or There Will Be elongation Just Like In this picture So this is tensile or elongation tensile stress This is shrinkage so There Will Be compressive strength and this is a shear stress okay so These are the ano Uh deformation deformation This is the strain no during there if there be a sh force that will be will be Uh applied no the formation will be elongation and then shrinkage naman There Will Be A shrinkage No if you're going to compress it no and Then she chest There Will Be no sheer no and then twisting there will torch and then bending movement There Will Be bending deformation for the tension no this results when a body is subjected to two sets of force directly away from each other in a straight line So Here as if they will parang tag of tag of War di ba So There Will Be forces in opposite direction so There Will Be A tension force So this will cause stretching No there will be stretch Uh on the material o kaya it will elongate for the torsion There Will it will to twisting of the twisting of the body of the material and then bending This is bending applying bending so There Will Be no yung one end to one one end to another end It will be a usually bend from longitudinal no longitudinal movement pag torsion there be Lateral no Lateral axis Okay ung stress Okay stress si first no This is the force No that acts on the body a resistance develop on the external force applied which is equal to the magnitude of the opposite direction applied which is called stress usually stress is equals to force over an area remember stress is equals force over an area meaning no example if no if you are sitting on your chair so that is the force that will be applied no and then the chair or the ch will Opo it will 3 May bisita Sige po ay hindi for a while lang ha I will just ano change the force that is applied over an area Okay and then for example No when you're going to Okay so for the stress This is the force of over Ana so when you're for example sitting on your chair So you're exerting force so that is the force and TH the Okay the chair that will the the for No that the chair is um resisting against your we is the stress okay so going to correlate it in Okay so when you're going to bite by do siguro When to conclude your te so there will force that will be that will be applied and then the force that the Teeth is resisting against the force that we are applying that will be the stress Okay so It depends on type of stress if it is Again the direction is towards the center or towards As if there will be Uh compression will be compression stress if there will be a Lateral movement that will sheing stress and if there will be stress that will the direction of The force is in two different directions As if you are pulling it apart that is Uh this sheing that is a shearing stress Okay so this will be this this will be the formula f is equ S f over a force over area yeah and remember pala no if the area if the area is smaller and the stress is and if the course is Larger There Will Be greater stress example no Uh if you're going to compare this is for the girls if you're going to compare if you are if you're going to wear a heels with a pointed heels or with isa Iyung which which do you think will exert more force or more force is it ung d sa sands orung hs with pointed heels or yung [Musika] wedge so any from sino yung magiging masakit magiging Parang mas the one orung paka yung wedge this is for only for ano girls which do think willer more force will create you know why it's because if the area is smaller than The Force There Will Be greater stress kasi It will be the one who will receive the force and in if you're going to restore a to if you will do a dation which is fix and then you want to dist aming to with fixes and that is for that will be a fix bridge so the abant must be enough to theat course kasi if it is smaller There Will Be A lot of stress that will be created and Later on the chain Will Be There Will Be pain so that will be the effect Okay so if the area no if the area is Larger Than The Force that is applied there will be less stress Okay so please remember that and then yung strain naman this will be the effect it refers to the deformation of an object to stress so example exle a while ago so kan pointed na is will create more stress or pain after It's because and that p is to There Will Be An effect so example don sa Kyo naman ' if there will be Uh enough no supporting kit that will Hold the restoration or the with Hold the the restoration No there will be less strain or there less there will be less of chance of fracture Okay example pa is if you're sitting on your chair and then if it is siguro ah you we is not will will not Larger Than the The Force that you are exerting right now on your chair and then your chair let's say ano siya medyo manipis later you will para siya mag curve and that will be the St Okay so this will be the deformation of an object after the stress is Okay so if it is due to compression will the if if the St the formation is DU to elongation that is because of shearing stress Okay so it may be in elastic plastic or both elastic and plastic Okay so another will proportional so when you say proportional limit is to the maximum stress at which stress is equivalent proportional to stange So if it is above with this limit No there will be deformation of the materials that will occur so usually it happens when it is subjected to any applied force So this will be the Uh graph Okay so This is the string This is the This is the str This is the stress and then This is the prop limit still no if there will be more force no more than this one There Will Be deformation that will happen Okay so still so proportional limit still this one It's still within the It's ano normal no normal state if it is beyond that one That's when the stange or the deformation will happen Okay When You Say yield no y the point Bey Which causes a material to undergo permanent deformation So if there will be fracture if the tooth or the rest cannot withstand theory force and it will flu that will be the y point that is there is the permanent deformation it will not go back to its original form Okay So this one sa yield point the stress is slightly higher than proportional limit Okay example for the gold anoy Okay proportional limit is 276 Meg So this can still no with the masticatory Forces but if no and and if it is more than that one There Will Be permanent deformation happens if this this Uh this Uh na size of Uh pressure or force will be applied If This is the amount of pressure that is applied doon so There Will Be A permanent deformation that will happen So it will not recover example no yung rubber band ba So initially going to stretch it a little siguro mga ah 1 cm if you're going to stretch it more no and then release So it will increase in size no so There Will Be deformation There Will Be strain and then it increase in size It's because it is beyond the proportionally so there is a yield point no so The force is Higher That's why there will be permanent deformation that happens okay for the modulus of elasticity I just want you to remember this one when you say when you hear the word modulus of elasticity No it refers to the stiffness or rigidity of the material kung gaano siya kaart I mean yung kanyang ka Okay so usually it is measured by the slope of elastic region just like what I've shown you in the prev Uh picture no So it is called as modulus Okay so if it is measured by slope or str curve So if the 10 is below the professional limit So this will still be obtain so ibig sabihin lang nito no if no if there will be High compressive stress no so mas mas ah higher Yung kanyang model of elasticity is stiffness siya So una affected by amount of elastic or classic indu material so is it is dependent to ductility Okay sa ductility so the lower the seene for a given stress No there will be greater elastic modulus so usually yung mga solid solid materials they have High nung kanyang modul of elasticity or St or leg yung stress strain curve for the material which ch is dependent the time load is applied Sur stress strain curves This is the ano stress St curve teka lang this one stress strain curve So you're going to determine no here so just remember if it is more than the proportional limit applied stress There Will Be ano permanent deformation or damage that will happen Tapos po ang clinical and okay for the analysis for the St and stain The One That i've showed you yung ano yung gra okay for the St and flexibility in ang longitudinal portion of the curve if it is closer to the long axis the material stif and not flexible and with is away for the long axis the material is flexible for a while para ma exc natin 4 [Musika] doc Wala po kayong audio Thank you for that Okay so going back to this one remember niyo lang no flexibility if the portion curve is closer to the stress the long axis meaning the material is has High modulus of elasticity or sff if it is away from the long axis meaning it is flexible or less ang kanyang stiffness or low less ung kanyang model of elasticity Okay and then for the toughness of littleness if the material no will have a long concave portion no so meaning it is tough and ductile but if is minimal yung show of curve just like this one so meaning that the material is brittle another will be the strength and weakness Okay so if the longitudinal portion curve this one no is longer okay meaning the material is strong but if it is no short meaning it is weak okay for the po Rao So it it refers to the cylindrical no So it can be in two no two direction it can be or it can Okay so here There Will Be A cous strain and Lateral so within its elastic strange So it the first poison This is the re of Lateral toal here here this will the the after after the after the stress after the compressive stress This is the compressive and she stress is applied for the strength when you say strength it refers the maximum stress that the material can withstand without sustaining specific amount of plastic stain or stress at point of fracture Kaya nga usually yungs products They have their compressive str we Say compressive str this is the strength which the material can still withstand the Forces h sila Okay so when I go to start talagang mga materials that I'm going to disc marami nakalagay compressive str str remember material High ng compressive strength mas less kanyang tel strength if the material is flexible mas higher ung kanyang tel strength mas less ang kanyang compressive strength okay for the sh strength naman Max She str at the point of fracture the fal St this is for the force for unit area of the point of the facture when the material is subjected to facture loading no so bending or modulus of rupture okay okay for the fatigue usually this one refers to the maximum service stress it can be without filler over Infinite number of cycles So it can limit is lower for the with or rough surface usually no yung mga wires if you're going to twist it more so There Will Be A fa that will be ano that will be lo no so It will be Uh break okay for the impact stress strength it is the reaction of stationary object a collision with moving body so usually No it is defined as energy required to fracture material usually if if the solid mater let product will fall it will fru okay okay for the toughness toughness This is the energy requ to fracture so i-relate siya model of elasticity yung word that you can correlate is stiffness or leg fracture Okay so energy that requ the material to fracture is toughness if it has High toughness ba So meaning less charge the material will fracture Okay also the total area under stress So if it is if it is ba kanina you have the longitude stress and the stain is yung sa x-axis if the St St curve is mas more on siya sa sa x-axis no mas less on Tess na but if it is nearer no to the Y axis no mas High to So this describes how difficult no the material to Ano to break no so usually yung mga restorations that usually place on the posterior they should have High or tough High tough It's because to withstand nastic para hindi sila mabilis mag Okay When you see an brital This is the oppos of the toughness Okay so this when the material factors are near in proportional should not be confused with the lack of Strength So vess this are the materials that can easily break Okay usually porcelain then the Stones cements examples of brital material so they can easily break But there are also leg they high high high El High modul of they have a high modulus of elasticity resilience no we say resilience This is resistance to deformation Okay resistance to deformation is resilience Okay so is amount of energy absorbed by a material when stress is that ex It's proportional limit Okay so usually it is measured in terms of modul ofili para hindi siya mabilis resistance deformation is resilience Okay so usually module of resilience is equivalent to proportional limit or mod of so meaning if the material is solid or Hard or rigid yungang resilience is Higher Okay hardness naman we hardness it pertains to resistance to [Musika] scratch usually based on disas scatch so mety laman it is somewhat hardness is defined as to indentation you know what there are different test are conducted to test the hardness of the material especially no yung mga ginagamit for the restoration like compos yung mga porcel This is to measure the limit the limitations of the use of the material or and what Uh point no and what Uh amount of load no the maty will break so that they can determine the compressive strength to 10 ch of the material Okay so higher hardest number more hardest So I will discuss this one yung yung usually how to to test hardest no of the material doon suong products Okay so hardness This is resistance of scratching resilient resistance to the formation relaxation This is changing shape DU release of stress is referred as relaxation example will be wax Okay Uh the problem with this one is ' ba when I discuss the history This this material was used as impression material if there be relaxation it meaning is after going to B it there is a high chance that it will go back to its original form So if you're going to use this one as impression material the tendency it will loen it will expand there is a high chance of deformation no if it is subjected to cold temperature it will contract and if it is subjected to higher temperature it will Uh this one it will expand Okay so meaning it has no you can you canya this [Musika] one reliability of the material so that is relaxation So it is common common in dental waxes Okay other material this includes the shell that we going to do interac number e okay for the permanent def again testing curve Okay so after crossing the elastic Lim with continuous There Will Be this will when it expands no usually too much or if you're going to move it it should be a single motion because there is a high chance that it will be there Okay so that will that when this permanent deformation will happen okay for the ductility Okay remember no for the ductility This is the ability of the material to deform Okay Usually the stress that is applied is tensile so remember ductility There Will Be the formation of the material due to stencil that is applied to it okay so example with the copper wire the copper metal It will be turned into a long wire so that is the Okay so the Philip tens stress ex sample will be from this one It will be into a wires for the malleability so there is a compressive stress that will apply Okay so ability of the mater to sustain PL information without fracture under compression Okay so example It will be the gold Okay This is the most valuable metal Okay so There Will Be material to deform PL under 10 substance before fracture So this is for the ano for the ductility okay for the for the malleability No there will be formation of into a thin sheet thin sheet ito so malleable There Will Be compression Okay so the most malleable metal is the gold followed by The Silver and then just for you to know the Platinum is the third among the metal which is ductile and copper as as a Okay so sa malleable don't be confused pable There Will Be compression that is applied So it will turn into a thin shap willing apart so There Will Be permission of wire Okay so that will end my our discussion for this after so Before I will dismiss you um I just want to ask the St you no if you have any questions or verifications regarding the topic for this afternoon or any clarifications so far Meron ba okay if not will so any volunteer Before I will give my question Hello Hello is