 Hello everyone, welcome back to another session in dentistry and more. Today we have a topic from Prostadontics but sometimes it is also asked in conservative dentistry that is CAD-CAM. So CAD-CAM is a field of dentistry mainly Prostadontics where the computer either design and computer manufacturing is used to improve the design and creation of dental restorations especially the dental processes which includes crowns, onlays, vinnies, inlays, the bridges, dental implant supported restorations, maybe removable and fixed, dentures, orthodontic appliances all those things. So this technology, this CAD-CAM technology allows the delivery of a well-fitting aesthetic and a durable processes for the patient. So conventionally we were using the lost wax technique. So lost wax technique in the production of metal castings or frameworks, their accuracy is greatly influenced by the properties of the impression materials, investment and casting alloy. This is nothing but a method of metal casting in which a molten metal is poured into a mold that has been created by means of a wax model. So once the mold is made the wax model is melted and drained away. So with the lost wax modeling method the fit of a crown of the dye can be satisfactory but there are chances of errors and same time it is time consuming. So in order to replace this time consuming and the method which has got errors we have computers to replace these designs and processing that is nothing but CAD-CAM. So we create milled restorations with accurate fit digitalization of the prepared tool surface and converting these data into signals for the computer assisted milling. So this CAD-CAM technology which was developed in the late 1980s for dentistry which incorporates milling technology and it significantly reduced or eliminated problems associated with dental castings. Now the CAD-CAM production concepts depending on the location of the components of the CAD-CAM system we have three different production concepts that is JSA production or laboratory production or centralized fabrication in a production center. So what are the components of CAD-CAM? So this is the most crucial part of CAD-CAM that is it has got three sections the first one is a data collecting tool or scanner it is just like the impression method what we commonly do in clinics but here we have scanner in order to take the impression or collect the data. The second part is designing software that is like will be done by the computer or software and finally the processing device. So this is will be a summary of the three techniques this is a scanner we use to record the impression then the computers with help of softwares will determine all the required data then it will be transferred to the milling unit and finally the product will be ready. So the first one is scanner it includes the data collection tools that measure three-dimensional joe and two structures this is just like how we take a three-dimensional impression using alginate using impression components a pretty impression so here we are using scanners and these data we transform into digital data sets so there are two different scanning possibilities one is optical and then the mechanical scanners the optical one is commonly used involves a connection of 3d structures in a so-called triangulation procedure so this is like software and it is more of a technological side so more than dentistry to understand this topic we need to have a knowledge about the computers its softwares and how it works so i'm not going in detail about those parts i'm just giving a brief idea about the concept the components and how it is done in CADCAM so this triangulation procedure or when using optical scanners the source of light and the receptor unit are in a definite anchor and which relationship to in the relationship to one another and this white light projections or a laser beam act as a source of illumination the second one is a mechanical scanner here there is no light instead the master cast is read mechanically line by line by means of a ruby ball and the three-dimensional structure measure so this is like mechanically we are doing without any help of the lights so this is a ruby ball which is measuring or which is recording the impression or in the cast that is three-dimensional structure will be read mechanically line by line so this type of scanner is distinguished by a high scanning accuracy but by the diameter of the ruby ball is said to the smallest grinder in the milling system so this is a ruby ball which will be attached to this one and this will record line by line with three-dimensional details so the problem so with this mechanical scanning is it is very expensive and long processing times will be taken compared to the optical system the second part that is the designing of the impression or the design designing or converting this data into a final model so this is equal to the all the procedures which is done in the lab that is investing wax pattern all those things so with the help of software this crown and fpds frameworks can be constructed some systems also offer the opportunity to design full anatomical crowns partial crowns in lace in lace retain fpds and telescopic primary crowns so the software is available in the market it is regularly updated this is an example of a software the data will be transferred to this software and here we create our final model and later this will be transferred to the mill so that is what I was saying it needs a more of a technical skill than a dental knowledge this is mostly a software thing which can be done by a software expert so there are various types of software is available in the market so the data of the construction can be stored in various data formats the basic format is a standard transformation language of stl data but many manufacturers will use their own data formats specific to that particular manufacturer now the processing device it is a final part where the actual product is created so the construction data produced with CAD software are converted to the milling strips for the cam processing there is a computer added machine processing and finally loaded into milling device so the device processing device are distributed by means of the number of milling accesses there are three times one is three access four access and five access devices so this is a milling device where the three access milling devices so this type of milling device has a degrees of movement in a three spatial direction that is x y z so this mill path points are uniquely defined by the x y and z values so a milling of subsections access divergence and convergence is not possible this demands a virtual blocking all those access divergence and convergence area so the advantage is that it is a short milling time and simplified control also these devices are less costly than those with a higher number of access so this is a basic type of milling device now we have uh this is three access i hope you can see this three access next one is four access milling devices in addition to three spatial accesses the tension bridge for the component can also be turned infinitely variable so as a result it is possible to adjust the bridge constructions with a large vertical height displacement into the usual mold dimension so that part will be added as a fourth access okay so it saves material and milling time so you can see x y z and a so this a is nothing but a vertical height displacement dimension so in five access milling devices in addition to three spatial dimensions and the rotatable tension bridge that is a fourth access the fifth access milling device has the possibility of rotating the milling spindle this enables the milling of complex geometries with complex shapes such as denture brace resins so this is a most sophisticated uh milling device that is five access milling device now we have the milling types two types are there one is a dry processing and wet processing in dry milling process it is applied mainly with respect to zirconium oxide blanks with a lower degree of pre-sintering the advantage is a minimal investment cost for the milling device no moisture absorption by the dye zirconium oxide mold but the disadvantage is higher shrinkage value for the framework but as a wet milling process the milling diamond or carbide cutter is protected by a spray of cold liquid against the overheating of the melt material so there will be a splashing of water so this is useful for all metals and glass ceramic material in order to avoid damage through heat development so this wet processing is recommended if zirconium oxide ceramic with a higher degree of pre-sintering is employed for the milling process so 3d printing also comes with this CAD cam so it is another manufacturing approach to build objects one layer at a time and adding multiple layers to form an object is also known as additive manufacturing or rapid prototyping this is very commonly used 3d printing to recreate the last orofacial structures so it may be used for the fabrication of metal structures either directly either indirectly by printing in resins of access for a lost wax process or directly in metals or metal alloys like fpd, rpd and polymerized processes and silicon processes so the materials normally processed by CAD cam systems includes metals, resin materials, silica base ceramics, in-filter ceramics and oxide ceramics so that was all about CAD cam this was a very brief idea of CAD cam the components its milling processes and the design so the milling designs and the components and this processing device then the designing software then the scanners and the three types of production so it was not an in-detailed session about CAD cam the CAD cam can be taken in 100 slides of a one hour because it involves a lot of technical side to explore about the software and all those milling processes this mainly to write a short note or short essay in university question paper hope you understood the brief idea of CAD cam designing and milling so i'll come up with a new topic in the industry and more thank you