Cad cam in prosthodontics

BY FATEEMA PRIYAM FEROZ,FINAL YR PG,PROSTHODONTICS

1. CAD/CAM IN PROSTHODONTICS Fateema Priyam Feroz IIIrd Year P.G Dept. of Prosthodontics 1

2. CONTENTS Introduction History General principles Components of CAD/CAM Subtractive and Additive techniques Evolution of CAD/CAM 2

3. Materials for CAD/CAM Common CAD/CAM systems Recent advances Advantages and disadvantages of CAD/CAM Summary Discussion Conclusion 3

4. INTRODUCTION 4

5. The long-term success of restorations depends, to a considerable extent ?????? With the conventional impression procedures ------- lost-wax-casting 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. 5

6. With the lost wax modeling method, the fit of a crown on the die can be satisfactory, but ???? Because traditional procedures are time-consuming , efforts have been made to replace these with computer-assisted procedures. 6

7. Milling of dental restorations from a block of base material, such as metal, ceramic or resin, is proposed as an alternative for fabricating restorations ????? To produce milled restorations with accurate fit, digitization of the prepared tooth surface and converting the data into control signals for computer-assisted milling is used. 7

8. Computer-aided design/computer-aided manufacturing (CAD/CAM) technology which was developed in the late 1980s for dentistry, incorporates the above mentioned techniques and it significantly reduced and/or eliminated problems associated with dental castings. 8

9. HISTORY 9

10. In dentistry, the major developments of dental CAD/CAM systems occurred in the 1980s. Dr. Duret – developer of Sopha System Dr. Moermann - the developer of the CEREC system Dr. Andersson - the developer of the Procera system 10

11. Dr. Duret fabricated crowns (1971) with the functional shape of the occlusal surface using a series of systems that started with an optical impression of the abutment tooth in the mouth, followed by designing an optimal crown considering functional movement, and milling a crown using a numerically controlled milling machine. 11

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14. Dr. Moermann , the developer of the CEREC system. He directly measured the prepared cavity with an intra-oral camera, which was followed by the design and carving of an inlay from a ceramic block using a compact machine set at chair-side. Benefit: ????????? 14

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16. Dr. Andersson , the developer of the Procera system Fabricated titanium copings by spark erosion and introduced CAD/CAM technology into the process of composite veneered restorations. Later developed as a system with processing center networked with satellite digitizers around the world for the fabrication of all-ceramic frameworks. 16

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19. GENERAL PRINCIPLES 19

20. CAD/CAM SYSTEMS All CAD/CAM systems consist of three components: A digitalization tool/scanner that transforms geometry into digital data that can be processed by the computer Software that processes data and, depending on the application, produces a data set for the product to be fabricated A production technology that transforms the data set into the desired product. 20

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22. CAD/CAM - PRODUCTION CONCEPTS Depending on the location of the components of the CAD/CAM systems, in dentistry three different production concepts are available: chairside production laboratory production centralised fabrication in a production centre . 22

23. CAD/CAM COMPONENTS 23

24. CAD/CAM components can be grouped into three: Scanner / Data collecting tool Design software Processing devices 24

25. 1. Scanner It includes the data collection tools that measure three dimensional jaw and tooth structures and transform them into digital data sets. Basically there are two different scanning possibilities: optical scanners mechanical scanners. 25

26. 1.a) Optical scanners It involves the collection of 3D structures in a so-called ‘triangulation procedure’. The source of light and the receptor unit are in a definite angle in their relationship to one another. White light projections or a laser beam can serve as a source of illumination 26

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28. Examples of optical scanners : Lava Scan ST (3M ESPE, white light projections) es1 ( etkon , laser beam). 28

29. 1.b) Mechanical scanner The master cast is read mechanically line-by-line by means of a ruby ball and the three-dimensional structure measured. The Procera Scanner from Nobel Biocare This type of scanner is distinguished by a high scanning accuracy, whereby the diameter of the ruby ball is set to the smallest grinder in the milling system 29

30. Drawbacks of the system: The apparatus is very expensive Long processing times compared to optical systems. 30

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32. 2. Design software With such softwares , crown and fixed partial dentures (FPD) frameworks can be constructed. Some systems also offer the opportunity to design full anatomical crowns, partial crowns, inlays, inlay retained FPDs, and telescopic primary crowns. The software available on the market is being continuously improved. 32

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35. The data of the construction can be stored in various data formats. The basis therefore is often standard transformation language (STL) data . Many manufacturers, however, use their own data formats, specific to that particular manufacturer. 35

36. 3. Processing devices The construction data produced with the CAD software are converted into milling strips for the CAM-processing and finally loaded into the milling device. Processing devices are distinguished by means of the number of milling axes: 3-axis devices 4-axis devices 5-axis devices. 36

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38. 3.a) 3-axis milling devices This type of milling device has degrees of movement in the three spatial directions, and so the mill path points are uniquely defined by the X -, Y -, and Z – values A milling of subsections, axis divergences and convergences, however, is not possible This demands a virtual blocking in such areas 38

39. The advantages of these milling devices are short milling times and simplified control by means of the three axis. Also these devices are less costly than those with a higher number of axes. Examples of 3-axis devises: inLab ( Sirona ), Lava (3M ESPE), Cercon brain ( DeguDent ). 39

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42. 3.b) 4-axis milling devices In addition to the three spatial axes, the tension bridge for the component can also be turned infinitely variably . As a result it is possible to adjust bridge constructions with a large vertical height displacement into the usual mould dimensions and thus save material and milling time. Example: Zeno (Wieland- Imes ). 42

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45. 3.c) 5-axis milling devices In addition to the three spatial dimensions and the rotatable tension bridge (4th axis), the 5-axis milling device has the possibility of rotating the milling spindle (5th axis) This enables the milling of complex geometries with complex shapes such as denture base resins. Trial of a Cad/Cam system for fabricating dentures-Dental materials journal-2011 45

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47. Example in the Laboratory Area: Everest Engine ( KaVo ). Example in the Production Centre: HSC Milling Device ( etkon ). 47

48. MILLING VARIANTS Dry processing Applied mainly with respect to zirconium oxide blanks with a low degree of pre-sintering. Advavtages : Minimal investment costs for the milling device No moisture absorption by the die ZrO2 mould Disadvantages: Higher shrinkage values for the frameworks. 48

49. EXAMPLES [Zeno 4030 (Wieland- Imes ), Lava Form and Cercon brain]. 49

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51. Wet milling In this process the milling diamond or carbide cutter is protected by a spray of cool liquid against overheating of the milled material. Useful for all metals and glass ceramic material in order to avoid damage through heat development. ‘Wet’ processing is recommended, if zirconium oxide ceramic with a higher degree of pre-sintering is employed for the milling process. 51

52. Examples: Everest ( KaVo ), Zeno 8060 (Wieland- Imes ), inLab (Sirona). 52

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55. 3 D PRINTING It is another manufacturing approach to build objects, one layer at a time and adding multiple layers to form an object. It is also known as additive manufacturing or rapid prototyping (RP). 55

56. It may be used for the fabrication of metal structures either indirectly by printing in burn-out resins or waxes for a lost-wax process, or directly in metals or metal alloys like FPD and removable partial denture (RPD), polymerized prostheses, and silicon prosthesis. 56

57. Selective laser sintering A scanning laser fuses a fine material powder, to build up structures layer by layer, as a powder bed drops down incrementally, and a new fine layer of material is evenly spread over the surface. Resolution as high as 60 μm may be obtained, and the structures printed are supported by the surrounding powder 57

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59. Stereolithography Light-sensitive polymer cured layer by layer by a scanning laser in a vat of liquid polymer. It is a widely employed RP technology. It was invented by Charles Hull . 59

60. It is an additive manufacturing process in which a liquid photocurable resin acrylate material is used. Stereolithography uses a highly focused Ultraviolet (UV) laser to trace out successive cross-sections of a 3D object in a vat of liquid photosensitive polymer 60

61. It may be used for the fabrication of metal structures either indirectly by printing in burn-out resins or waxes for a lost-wax process, or directly in metals or metal alloys like FPD and removable partial denture (RPD), polymerized prostheses, and silicon prosthesis. 61

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63. Currently, subtractive milling is the most widely implemented computer-aided manufacturing protocol in dentistry and it has been shown to be a suitable method for fabricating intraoral prostheses. 63

64. Additive methods have the advantage of producing large objects, with surface irregularities, undercuts, voids, and hollow morphology that makes them suitable for manufacturing facial prostheses and metal removable partial denture frameworks. 64

65. EVOLUTION OF CAD CAM 65

66. 66 Evolution of software and hardware in CAD CAM 2017

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70. Materials for CAD/CAM Processing 70

71. Materials Materials for processing by CAD/CAM devices depends on the respective production system Some milling devices are specifically designed for the production ZrO2 frames , while others cover the complete palette of materials from resins to glass ceramics and high performance ceramics. 71

72. The materials normally processed by CAD/CAM systems include: Metals Resin materials Silica based ceramics Infiltrated ceramics Oxide ceramics 72

73. Metals Presently titanium, titanium alloys and chrome cobalt alloys are processed using dental milling devices. The milling of precious metal alloys has been shown to be of no economic interest, due to the high metal attrition and the high material costs. Examples: coron ( etkon : non-precious metal alloy), Everest Bio T-Blank ( KaVo , pure titanium). 73

74. Resin material It is possible to use resin materials directly as crown and FPD frameworks for long-term provisional or for full anatomical long-term temporary prostheses???? Prefabricated semi-individual polymer blanks (semi-finished) with a dentine-enamel layer are provided by one manufacturer ( artegral imCrown , Merz Dental). 74

75. The first commercial resin composite for CAD/CAM –Paradigm MZ100(3M ESPE) 75

76. Silica Based Ceramics Grindable silica based ceramic blocks are offered by several CAD/CAM systems for the production of inlays, onlays , veneers, partial crowns and full crowns It is usually available as monochromatic blocks Various manufacturers now offer blanks with multicoloured layers [ Vitablocs TriLuxe (Vita), IPS Empress CAD Multi ( IvoclarVivadent )], for the purpose of full anatomical crowns. 76

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78. Lithium disilicate ceramic blocks -full anatomical anterior and posterior crowns,copings in the anterior and posterior region and for three-unit FPD frameworks in the anterior region due to their high mechanical stability of 360 MPa 78

79. Glass Ceramics Glass ceramics are particularly well suited to chairside application due to their translucent characteristics, similar to that of the natural tooth structure. Provides esthetically pleasing results without veneering. Etchable with hydrofluoric acid due to their higher glass content – can be inserted very well using adhesive systems. 79

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81. Infiltration Ceramics Grindable blocks of infiltration ceramics are processed in porous, chalky condition and then infiltrated with lanthanum glass. All blanks for infiltration ceramics originate from the Vita In-Ceram system (Vita) and are offered in three variations: Vita In-Ceram Alumina (Al2O3) Vita In-Ceram Zirconia (70% Al2O3, 30% ZrO2) VITA In-Ceram Spinell (MgAl2O4) 81

82. Vita In-Ceram Alumina (Al2O3): suitable for crown copings in the anterior and posterior region, three-unit FPD frameworks in the anterior region Vita In-Ceram Zirconia (70% Al2O3, 30% ZrO2): suitable for crown copings in the anterior and posterior region, three-unit FPD frameworks in the anterior and posterior region. Suitable for discolored teeth due to its superior masking ability 82

83. VITA In-Ceram Spinell (MgAl2O4): Highest translucency of all oxide ceramics and is thus recommended for the production of highly aesthetic anterior crown copings, in particular on vital abutment teeth and in the case of young patients. 83

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86. COMMON COMMERCIAL CAD/CAM SYSTEMS 86

87. CAD/CAM systems may be categorized as: In-office system Laboratory based system Milling center system 87

88. In-Office systems 88

89. CEREC Sirona , with their CEREC line of products, is the only manufacturer that currently provides both in-office and laboratory-based systems. CEREC 1 and CEREC 2 – optical scan of the prepared tooth with a charged-coupled device (CCD) camera, and the system automatically generates a 3D digital image on the monitor Then, the restoration is designed and milled 89

90. With the newer CEREC 3D , the operator can record multiple images within seconds. This enables the clinicians to prepare multiple teeth in the same quadrant and create a virtual cast for the entire quadrant. On the virtual model, the operator designs the contour of the restoration and electronically transmits the data to a remote milling unit for fabrication. Better marginal adaptation 90

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92. Laboratory-Based Systems 92

93. CEREC inLab It is a laboratory-based system Working dies are laser-scanned and a digital image of the virtual model is displayed on a computer screen. After designing the coping or framework, the laboratory technician inserts the appropriate ceramic block into the CEREC inLab machine for milling. 93

94. A wide range of high strength ceramic blocks are available for the inLab system It includes Vita In-Ceram blocs two sintered ceramics: inCoris ZI (zirconium oxide) and inCoris AL ( aluminium oxide) (Sirona Dental Systems, LLC). After milling, the technician manually inspects and verifies the fit of the milled coping or framework on the die and working cast. 94

95. Subsequently, the coping will be adjusted to maximize adaptation to the die. The coping or framework then is either glass-in filtrated (Vita In-Ceram) or sintered (zirconium oxide or aluminium oxide), and the veneering porcelain is added 95

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97. Milling Center Systems 97

98. DCS Precident The system is comprised of a Preciscan laser scanner and Precimill CAM multitool milling center. It can scan 14 dies simultaneously and mill up to 30 framework units in a single, fully automated operation. It can mill titanium as well as fully dense sintered zirconia. 98

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100. Procera Procera / AllCeram was introduced in 1994 Uses an innovative concept for generating alumina and zirconia copings. The master die is scanned and the data is send to the processing center. After processing,the coping is send back to the lab for porcelain veneering. 100

101. The recommended preparation marginal design for a Procera / AllCeram restoration is a deep chamfer or shoulder with a rounded internal line angle and a well-defined cavosurface finish line. The recommended coping thickness is 0.4 mm to 0.6 mm. 101

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103. Nobel Biocare USA LLC has introduced various implant abutments for its Procera system — titanium (1998) alumina (2002) zirconia (2003) Capable of generating alumina (two to four units) and zirconia (up to 14 units) bridge copings. The occlusal -cervical height of the abutment should be at least 3 mm, and the pontic space should be less than 11 mm. 103

104. VIDEO PRESENTATION 104

105. NEWER CONCEPTS 105

106. Cercon (2002) Wax pattern (coping) with a minimum thickness of 0.4 mm are to be made which is scanned and the Cercon Brain milling unit milled a zirconia coping from proprietary presintered zirconia blanks. The coping then was sintered in the Cercon Heat furnace (1350 C) for 6 to 8 hrs. A low-fusing, leucite -free Cercon Ceram S veneering porcelain was used to provide the esthetic contour. 106

107. In 2005, DENTSPLY Ceramco introduced the Cercon Eye 3D laser optical scanner and Cercon Art CAD design software. Now, as a complete CAD/CAM system, Cercon can produce single units and bridges up to nine units from pre-sintered zirconia milling blocks that are offered in white and ivory shades without any infiltration required 107

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109. Lava Lava system Introduced in 2002. It includes a mobile cart,a touch screen display and a scanner with camera at the end. Camera has LEDs and lens systems Data-send through wireless to the laboratory where the die is cut and margins are marked digitally. 109

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111. CEREC The system offers two possibilities: Scanning for in-office fabrication Sending digital images to the laboratory Transfer is only possible if the laboratory has CEREC CONNECT Light source: LED (blue visible light) 111

112. CEREC AC machine 112

113. The occlusion is recorded by simply scanning the arches, and digital on-screen articulating paper shows where there are contacts. 113

114. Image acquisition is more rapid with CEREC AC The clinician can verify the preparation and interocclusal clearance The system will also digitally mark the margins and provide a digital version of the proposed restoration prior to its fabrication 114

115. Lava C.O.S. The Lava C.O.S. system is used for chairside digital impression making Scanner contains 192 LEDs and 22 lens systems with a pulsating blue light It uses continuous video to capture the data that appears on the computer touch screen during scanning 2,400 data sets are captured per arch. 115

116. Can rotate and magnify the view on the screen Full arch is scanned after the preparation imaging is complete, followed by the opposing quadrant, and the occlusion is assessed Images can be transmitted directly to an authorized laboratory 116

117. Laboratory technician digitally marks the margins and sections the virtual model prior to sending this digitally to the manufacturer The model is then virtually ditched, articulated and sent to the model fabrication center for stereolithography (SLA) to create acrylic models 117

118. Lava C.O.S. system 118

119. KELKAR 119

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121. TWO VISIT CAD CAM DENTURE REHABILITATION-A CASE REPORT 121

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130. Advantages 130

131. The advantages of using CAD/CAM technology for the fabrication of crowns and FPDs can be summarized as: 1) application of new materials 2) reduced labor 3) cost effectiveness and 4) quality control. 131

132. High-strength ceramics that were expected to be the new materials for FPDs frameworks have been difficult to process using conventional dental laboratory technologies. CAD/CAM offers a solution for this. CAD/CAM technology was useful and effective in compensating for changes in dimensions that come with processing chalky material and post-treatment to obtain fit of crowns and FPDs to abutment teeth. 132

133. Conventional dental laboratory technologies are traditionally labor-intensive and the labor was vastly reduced using CAD/CAM machine. Conventional porcelain dental laboratory processing with powder build-up and baking required a degree of proficiency both in terms of reproducing natural esthetics and shaping – increases the cost CAD/CAM due to mass production can reduce the cost. 133

134. Drawbacks: Need for costly equipment Need for extended training Technique sensitive Inability to image in a wet environment 134

135. The powder layer applied to the tooth surface results in an additional thickness of 13 to 85 μm . The restricted measuring conditions in the mouth, including the presence of adjacent teeth, gingiva, and saliva, make accurate recognition of the margin of an abutment difficult 135

136. Regardless of the digitizing mode applied, clinical parameters, such as saliva, blood, or movements of the patient can affect the accurate reproduction of teeth. 136

137. DISCUSSION 137

138. SUMMARY 138

139. Newer CAD/CAM systems demonstrate increasing user friendliness, expanded capabilities, improved quality, and greater range in complexity and application. Chairside digital impressions systems allow for the creation of accurate and precise laboratory models and restorations involving less chairside time. 139

140. Fractures of ceramic FPDs tended to occur in the connector areas because of the concentrated stress. Therefore, the design of the connector, particularly the dimensions, must be made independently depending on the type of ceramic material used for the framework. CAD better guarantees the durability and reduces the risk of fracture. Processing data can be saved and followed up during the functional period for the device. 140

141. To conclude, As Duret stated, “The systems will continue to improve in versatility, accuracy, and cost effectiveness and will be a part of routine dental practice in coming time”. 141

142. REFERENCES 142

143. Text books 1. Anusavice , Shen , Rawls; Phillip’s Science of Dental Materials 2013, 12 th edition, Elsevier. 2. Ronald L Sakguchi , John M Powers; Craig’s Restorative Dental Materials 2013, 13 th edition, Elsevier. 3. Marco Anntonio Bottino ; Perception: Esthetics in Metal Free Prosthesis of Natural Teeth and Implants 2009, Artis Medicas Dentistry. 4. Bernard Touati , Paul Miara , Dan Nathanson : Esthetic Dentistry and Ceramic Restorations 1999, informa healthcare. 143

144. Journals 1. AD Bona, AD Noguiera , OE Pecho ; Optical properties of CAD/CAM ceramic sysems ; J Dent 2014, 42: 1202-09 2. GD Quin , AA Guiseppetti , KH Hoffman; Chipping fracture resistance of dental CAD/CAM restorative materials; Dent Mater 2014, 30(5): e112-e123 3. Z Zhang, Y Tamaki, Y Hotta , T Miyasaki ; Novel method for titanium crown casting using a combination of wax patterns fabricated by a CAD/CAM system and a non expanded investment; Dent Mater 2006, 22: 681-87. 144

145. 4. O Moldovan, RG Luthardt , N Corcodel , H Rudolph; Three dimensional fit of CAD/CAM made zirconia copings; Dent Mater 2011, 27: 1273-78. 5. S Giaunetopoulos , RV Noort , E Triston; Evaluation of the marginal integrity of ceramic copings with different marginal angles using two different CA/CAM systems; J Dent 2010, 38: 980-86. 6. ER Batson, LF Cooper, I Duqum , G Mendonca ; Clinical outcomes of three different crown systems with CAD/CAM technology; J Prosthet Dent 2014, 28(5): 234-40 145

146. 7. Raul Euan , OF A lvarez , JC Termes , RO Parra; Marginal adaptation of zirconium dioxide copings: Influence of the CAD/CAM system and the finish line design; J Prosthet Dent 2014, 112: 155-62. 8. C Chen, FZ Trindade , N de Jager , CJ Kleverlaan , AJ Feilzer ; The fracture resistance of a CAD/CAM resin nano -ceramic (RNC) and a CAD ceramic at different thickness; Dent Mater 2014, 30: 954-62. 9. Jeramies Hey, F Beur , T Bensel , AF Boeckler ; Single crowns with CAD/CAM fabricated copings from titanium: 6 year clinical results; J Prosthet dent 2014, 112: 150-154. 146

147. 10. AC Johnson, A Versluis , D Tantbirojn , S Ahuja; Fracture strength of CAD/CAM composite and composite-ceramic occlusal veneers; J Prosthodont Res 2014, 58(2): 107-114. 11. NS Birbaum , HB Aoronson ; Dental impressions using 3D digital scanners: Virtual becomes reality; Compendium 2008, 29(8): 494-505. 12. T Miyasaki , Y Hotta , J Kuni et al; a REVIEW OF DENTAL cad/cam: Current status and future perspectives from 20 years of experience; Dent Mater 2009, 28(1): 44-56. 147

148. 13. PR Liu, ME Essig ; A panorama of dental CAD/CAM restorative systems; Compendium 2008, 29(8): 482-493. 14. A Begum, R Ahmed, S Islam; Digital impressions; City Dental College J 2012, 9(2): 31-34. 15. SS Manthri , AS Bhasin ; CAD/CAM in dental restorations: An overview; Annals and Essens of Dentistry 2010, II (3): 123-28. 148

149. THANK YOU 149