- Email: [email protected]
CAM
DENTAL TECHNIQUE
Complete denture fabrication supported by CAD/CAM Timea Wimmer, Dr med dent,a Korbinian Gallus, BSc, CDT,b Marlis Eichberger, CDT,c and Bogna Stawarczyk, PD Dr rer biol hum Dipl Ing (FH), MSc, CDTd The use of computer-aided ABSTRACT design/computer-aided manuThe inclusion of computer-aided design/computer-aided manufacturing (CAD/CAM) technology facturing (CAD/CAM) techinto complete denture fabrication facilitates the procedures. The presented workflow for complete niques for fabricating fixed and denture fabrication combines conventional and digitally supported treatment steps for improving removable partial dental prosdental care. With the presented technique, the registration of the occlusal plane, the determination theses has been widely reof the ideal lip support, and the verification of the maxillomandibular relationship record are considered. (J Prosthet Dent 2015;-:---) ported.1 However, less has been published on its use for allows for making the dentures in 2 clinical visits.12 At the complete dentures.2-11 Initial reports were on the devel3-7 first visit, the impressions, the maxillomandibular relaopment and proof of concept. In 1994, the use of 3tionship record, and the tooth selection are completed, dimensional (3D) laser lithography was described for the and, at the second visit, the complete dentures are delivfabrication of complete dentures of photopolymerized ered. With this technique the dentures are fabricated composite resin.5 The outer shells were fabricated by using without the need for casts, flasking, or other processing laser lithography, and the inside was filled with acrylic methods. Additionally, a review was published which composite resin. A few years later, a method of duplicating focused on the DENTCA system.13 The DENTCA system, a complete denture using CAD/CAM technology with a similar to the AvaDent system, enables denture fabrication computerized numeric control processor for cutting in 2 visits, although, a conventional processing technique modelling wax was presented.4 It took approximately 10 is necessary. The use of CAD/CAM record bases, made years until the next study presented their CAD/CAMwith the AvaDent system, was described for the fabrication aided method for the fabrication of complete dentures. of complete dentures.14 Virtual flasks were constructed according to the CAD The conventional method of fabricating complete denture casts, and individualized physical flasks were dentures has been established for over 80 years.15 It almade with a 3D printer.6 A recent study described a clinical lows for modification of the arrangement of teeth and the impression procedure for obtaining the morphology of evaluation of the treatment steps before delivery. denture bases and the muscular and phonetic positions of Nonetheless, the conventional method has disadvanthe denture teeth. Subsequently, the recorded information tages, including the number of patient visits (at least 5 are was scanned, and the complete denture bases were needed plus the visits after insertion), the high treatment virtually designed and milled from resin.7 Nevertheless, costs associated with these visits and the time- and costclinical reports are scarce. In 2012, a complete denture trial intensive laboratory work. The inclusion of CAD/CAM placement method using a rapid prototyping protocol was technology for the fabrication of complete dentures may presented and compared with a conventional trial.9 A reduce cost-intensive laboratory work. The present report clinical report in 2014 dealt with the CAD/CAM fabrication of a clinical treatment provides a step-by-step description of complete dentures using the AvaDent system, which a
Assistant Professor, Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany. Student Assistant, Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany. c Dental Technician, Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany. d Senior Materials Scientist, Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany. b
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5. Figure 1. Preoperative condition. A, Maxilla. B, Mandible.
of a CAD/CAM-supported method for fabricating complete dentures. TECHNIQUE 1. In the dental operatory, examine the patient (Fig. 1) and make anatomic impressions (Alginoplast,
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regular set; Heraeus Kulzer GmbH) of the edentulous maxillary and mandibular arches and send them to the dental laboratory for the fabrication of casts and custom trays. Make definitive impressions (Impregum Penta; 3M ESPE) of the maxilla and mandible and send them to the laboratory for the fabrication of definitive casts, record bases for the maxillomandibular relationship record, and a maxillary baseplate for facebow transfer. Make the facebow and jaw relationship records and determine the smile line, the positions of the canines and the midline, and the position of the anterior teeth for appropriate lip support and optimal esthetics (Fig. 2A). Send the records to the dental laboratory so that the casts can be mounted on an articulator (Fig. 2B) and for the virtual design of the complete dentures with the software (Ceramill Mind/D-Flow; Amann Girrbach). In the dental laboratory, scan the definitive casts separately with an optical scanner (Ceramill Map400; Amann Girrbach) (Fig. 3A,B). Then, scan the casts and the occlusion rim positioned in the transfer stand (Ceramill Transferkit; Amann Girrbach) (Fig. 3C). Import the data into the software to design complete dentures (Ceramill Mind/D-Flow; Amann Girrbach). Mount the scanned maxillary and mandibular casts virtually according to the scanned occlusion rim. For this, superimpose the files digitally and combine them by means of best-fit matching (Fig. 4). Set the occlusal plane with the help of the occlusion rim (Fig. 5A) and analyze the casts with the help of the step-by-step instruction in the software. Mark the anatomic characteristics of the cast surfaces, the position of the first premolars, and the center line with the margin lines (Fig. 5B).
Figure 2. Occlusal record. A, Occlusion rims connected with registration paste (Superbite: zinc oxide eugenol bite registration paste; Harry J. Bosworth Co) and marked reference lines. B, Casts and occlusion rims mounted in articulator.
THE JOURNAL OF PROSTHETIC DENTISTRY
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Figure 4. Virtual mounting of casts by means of best-fit matching.
9. 10.
11.
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Figure 3. Screenshots of scanned casts. A, Maxillary. B, Mandibular. C, Occlusion rim between casts.
Determine the boundary line for the anterior teeth on the basis of the maxillary record base. With the entered information, the software calculates the common arrangement lines and suggests an applicable set of artificial teeth (Fig. 5C). The deposited artificial teeth are conventionally manufactured teeth made of acrylic resin from different manufacturers and not produced by CAD/CAM technology. 7. Select the preferred artificial teeth and let the software automatically arrange them in their correct position (Fig. 5D). 8. Design the gingival parts of the dentures on the basis of the suggestion of the software with the Wimmer et al
14.
15. 16.
help of the different tools provided, for example, a virtual wax knife or paint brush (Fig. 5E). Send a preview of the virtual arrangement to the clinician for evaluation. Shorten the basal surfaces of the artificial teeth virtually according to the contour of the alveolar ridges and the minimum denture thickness and provide them with retention for later fixation in the denture bases. Generate the data sets for the denture bases and the tooth sockets. Mill the denture bases with a 5-axis milling machine from a gingiva-colored wax blank (Ceramill D-Wax, Ceramill Motion 2; Amann Girrbach). Modify the conventional denture teeth according to the individual clinical situation. For this, mount them in a special blank/device and mill their basal surfaces corresponding to the prior computation. (Ceramill Motion 2; Amann Girrbach). Wax the adapted denture teeth into the sockets of the wax bases (Fig. 6) and evaluate the completed trial denture in the conventional articulator (Fig. 7). Send the trial denture to the clinician. In the dental office, evaluate the trial dentures in the patient’s mouth. Make adjustments to the arrangement in the conventional way, if necessary. Send the trial dentures to the dental laboratory for their completion by flasking. Deliver the completed dentures (Fig. 8, 9).
DISCUSSION It has been 20 years since the implementation of CAD/ CAM technology in the fabrication of complete dentures was reported. In the last few years, significant advancements have taken place in this field, and the first case reports have been published.12,13 The presented concept of Ceramill Full Denture Workflow incorporates CAD/CAM technology into the workflow of fabricating complete dentures. However, incorporation refers only to the tooth arrangement, the THE JOURNAL OF PROSTHETIC DENTISTRY
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Figure 5. Digital workflow of designing complete dentures. A, Setting occlusal plane. B, Cast analysis. C, Proposal for tooth arrangement. D, Articulator settings. E, Proposal for gingival design. F, Milling data for maxillary complete denture including tooth sockets.
milling of the wax trial bases, and the modification of the denture teeth so that they can be inserted into the tooth sockets of the bases with wax and without additional grinding. Compared with the completely conventional technique of fabricating dentures, this procedure has several advantages. Scanning the maxillary and mandibular casts and importing them into the software allows for better detection and visualization of the morphology of the edentulous maxillary and mandibular arches. Virtual sectional views facilitate the identification of anatomic characteristics, and, with the help of a software algorithm, the midlines of the alveolar ridges, for example, can be identified. A further advantage is that the virtual THE JOURNAL OF PROSTHETIC DENTISTRY
arrangement of the artificial teeth is a reproducible procedure enabling predictable results. With the help of the virtual articulator, static occlusion and the dynamic relation of the dentures are considered during digital arrangement. Also, the digitized maxillary record base can be taken into account, particularly for anterior teeth arrangement. With the correct incisal edge position of the maxillary teeth, ideal lip support can be realized. Moreover, the maxillary record base will be used to establish the plane of occlusion. Posterior teeth can be arranged according to the occlusal concept of the manufacturer. Thus, an ideal contact situation can be achieved. The arrangement can be performed in significantly less time in comparison with the manual Wimmer et al
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2015
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Figure 6. Milled wax dentures. A, Maxillary upper surface with teeth inserted. B, Maxillary intaglio. C, Mandibular upper surface with teeth inserted. D, Mandibular intaglio.
Figure 7. Milled wax dentures in articulator. Figure 8. Completed dentures.
arrangement. Additionally, the time-consuming procedure of manual waxing is eliminated. The polished surfaces of the denture bases can be easily designed with different anatomic features, for example, stippling and rugae. A preview of the virtual arrangement can be sent to the clinician for approval. If modifications of the tooth arrangement are required, this is possible. Also, for example, for adjustments for esthetic reasons, the arrangement can be superimposed with the digitized record bases. Wimmer et al
At the trial placement, minor adjustments of the arrangement can be made in the conventional way. In case of extensive modification, the wax denture base can be milled once more according to the required arrangement, and a second evaluation appointment is possible. Indeed, in the presented patient case, increasing the vertical dimension of occlusion was necessary. The dental technician unscrewed the anterior guide pin and THE JOURNAL OF PROSTHETIC DENTISTRY
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difficult and fault-prone. Development should focus on this field. Also, the problem concerning the durability of the bond between the base and the teeth has not been solved. Clinical and laboratory research is necessary to validate the new computer-aided treatment procedures for the fabrication of complete dentures.10 SUMMARY Incorporation of CAD/CAM technology into the design and fabrication of complete dentures helps to simplify laboratory work and standardize complete denture fabrication. Ceramill Full Denture Workflow is a CAD/ CAM-based system. With the help of proprietary software, the denture teeth can be arranged and bases designed. Dentures bases are milled from a wax blank, allowing for adjustments after clinical evaluation. REFERENCES
Figure 9. A, B, Patient with complete dentures.
remounted the mandibular cast in the articulator with the occlusion rim. As a facebow record had been made, increasing the vertical dimension did not entail errors in the occlusion. The situation was transferred into the virtual articulator, and a new mandibular tooth arrangement was designed with the software. The virtual design of complete dentures allows for consistent thickness of the bases. The material thickness can be adjusted to the material and kept minimal, allowing for the function and durability of the dentures. Furthermore, a consistent material thickness minimizes deviations in the contact relationships of the teeth, for example, due to polymerization shrinkage, and enables an improved fit to the mucosa, which is important for denture retention.16-18 The dentures may be easily duplicated with the digital data and research in this field is facilitated.10 With the system used here (Ceramill Full Denture Workflow), complete dentures can be digitally completed by milling them from prepolymerized acrylic resin blocks. However, the manufacturer does not currently enable this option because of the risk of remake. The source of error is the manual maxillomandibular relationship record, which is THE JOURNAL OF PROSTHETIC DENTISTRY
1. van Noort R. The future of dental devices is digital. Dent Mater 2012;28:3-12. 2. Busch M, Kordass B. Concept and development of a computerized positioning of prosthetic teeth for complete dentures. Int J Comput Dent 2006;9:113-20. 3. Kanazawa M, Inokoshi M, Minakuchi S, Ohbayashi N. Trial of a CAD/CAM system for fabricating complete dentures. Dent Mater J 2011;30:93-6. 4. Kawahata N, Ono H, Nishi Y, Hamano T, Nagaoka E. Trial of duplication procedure for complete dentures by CAD/CAM. J Oral Rehabil 1997;24:540-8. 5. Maeda Y, Minoura M, Tsutsumi S, Okada M, Nokubi T. A CAD/CAM system for removable denture. Part I: fabrication of complete dentures. Int J Prosthodont 1994;7:17-21. 6. Sun Y, Lu P, Wang Y. Study on CAD&RP for removable complete denture. Comput Methods Programs Biomed 2009;93:266-72. 7. Goodacre CJ, Garbacea A, Naylor WP, Daher T, Marchack CB, Lowry J. CAD/CAM fabricated complete dentures: concepts and clinical methods of obtaining required morphological data. J Prosthet Dent 2012; 107:34-46. 8. Zhang YD, Jiang JG, Liang T, Hu WP. Kinematics modeling and experimentation of the multi-manipulator tooth-arrangement robot for full denture manufacturing. Journal of medical systems 2011;35:1421-9. 9. Inokoshi M, Kanazawa M, Minakuchi S. Evaluation of a complete denture trial method applying rapid prototyping. Dent Mater J 2012;31: 40-6. 10. Bidra AS, Taylor TD, Agar JR. Computer-aided technology for fabricating complete dentures: systematic review of historical background, current status, and future perspectives. J Prosthet Dent 2013;109:361-6. 11. Lebon N, Tapie L, Vennat E, Mawussi B. Influence of CAD/CAM tool and material on tool wear and roughness of dental prostheses after milling. J Prosthet Dent 2015;114:236-47. 12. Infante L, Yilmaz B, McGlumphy E, Finger I. Fabricating complete dentures with CAD/CAM technology. J Prosthet Dent 2014;111:351-5. 13. Kattadiyil MT, Goodacre CJ, Baba NZ. CAD/CAM complete dentures: a review of two commercial fabrication systems. J Calif Dent Assoc 2013;41:407-16. 14. McLaughlin JB, Ramos V Jr. Complete denture fabrication with CAD/CAM record bases. J Prosthet Dent 2015;114:493-7. 15. Jacob RF. The traditional therapeutic paradigm: complete denture therapy. J Prosthet Dent 1998;79:6-13. 16. Artopoulos A, Juszczyk AS, Rodriguez JM, Clark RK, Radford DR. Threedimensional processing deformation of three denture base materials. J Prosthet Dent 2013;110:481-7. 17. Darvell BW, Clark RK. The physical mechanisms of complete denture retention. Br Dent J 2000;189:248-52. 18. Chen JC, Lacefield WR, Castleberry DJ. Effect of denture thickness and curing cycle on the dimensional stability of acrylic resin denture bases. Dent Mater 1988;4:20-4. Corresponding author: Dr Timea Wimmer Goethestraße 70, 80336 Munich GERMANY Email: [email protected] Copyright © 2015 by the Editorial Council for The Journal of Prosthetic Dentistry.
Wimmer et al
Complete denture fabrication supported by CAD/CAM Timea Wimmer, Dr med dent,a Korbinian Gallus, BSc, CDT,b Marlis Eichberger, CDT,c and Bogna Stawarczyk, PD Dr rer biol hum Dipl Ing (FH), MSc, CDTd The use of computer-aided ABSTRACT design/computer-aided manuThe inclusion of computer-aided design/computer-aided manufacturing (CAD/CAM) technology facturing (CAD/CAM) techinto complete denture fabrication facilitates the procedures. The presented workflow for complete niques for fabricating fixed and denture fabrication combines conventional and digitally supported treatment steps for improving removable partial dental prosdental care. With the presented technique, the registration of the occlusal plane, the determination theses has been widely reof the ideal lip support, and the verification of the maxillomandibular relationship record are considered. (J Prosthet Dent 2015;-:---) ported.1 However, less has been published on its use for allows for making the dentures in 2 clinical visits.12 At the complete dentures.2-11 Initial reports were on the devel3-7 first visit, the impressions, the maxillomandibular relaopment and proof of concept. In 1994, the use of 3tionship record, and the tooth selection are completed, dimensional (3D) laser lithography was described for the and, at the second visit, the complete dentures are delivfabrication of complete dentures of photopolymerized ered. With this technique the dentures are fabricated composite resin.5 The outer shells were fabricated by using without the need for casts, flasking, or other processing laser lithography, and the inside was filled with acrylic methods. Additionally, a review was published which composite resin. A few years later, a method of duplicating focused on the DENTCA system.13 The DENTCA system, a complete denture using CAD/CAM technology with a similar to the AvaDent system, enables denture fabrication computerized numeric control processor for cutting in 2 visits, although, a conventional processing technique modelling wax was presented.4 It took approximately 10 is necessary. The use of CAD/CAM record bases, made years until the next study presented their CAD/CAMwith the AvaDent system, was described for the fabrication aided method for the fabrication of complete dentures. of complete dentures.14 Virtual flasks were constructed according to the CAD The conventional method of fabricating complete denture casts, and individualized physical flasks were dentures has been established for over 80 years.15 It almade with a 3D printer.6 A recent study described a clinical lows for modification of the arrangement of teeth and the impression procedure for obtaining the morphology of evaluation of the treatment steps before delivery. denture bases and the muscular and phonetic positions of Nonetheless, the conventional method has disadvanthe denture teeth. Subsequently, the recorded information tages, including the number of patient visits (at least 5 are was scanned, and the complete denture bases were needed plus the visits after insertion), the high treatment virtually designed and milled from resin.7 Nevertheless, costs associated with these visits and the time- and costclinical reports are scarce. In 2012, a complete denture trial intensive laboratory work. The inclusion of CAD/CAM placement method using a rapid prototyping protocol was technology for the fabrication of complete dentures may presented and compared with a conventional trial.9 A reduce cost-intensive laboratory work. The present report clinical report in 2014 dealt with the CAD/CAM fabrication of a clinical treatment provides a step-by-step description of complete dentures using the AvaDent system, which a
Assistant Professor, Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany. Student Assistant, Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany. c Dental Technician, Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany. d Senior Materials Scientist, Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany. b
THE JOURNAL OF PROSTHETIC DENTISTRY
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5. Figure 1. Preoperative condition. A, Maxilla. B, Mandible.
of a CAD/CAM-supported method for fabricating complete dentures. TECHNIQUE 1. In the dental operatory, examine the patient (Fig. 1) and make anatomic impressions (Alginoplast,
6.
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Issue
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regular set; Heraeus Kulzer GmbH) of the edentulous maxillary and mandibular arches and send them to the dental laboratory for the fabrication of casts and custom trays. Make definitive impressions (Impregum Penta; 3M ESPE) of the maxilla and mandible and send them to the laboratory for the fabrication of definitive casts, record bases for the maxillomandibular relationship record, and a maxillary baseplate for facebow transfer. Make the facebow and jaw relationship records and determine the smile line, the positions of the canines and the midline, and the position of the anterior teeth for appropriate lip support and optimal esthetics (Fig. 2A). Send the records to the dental laboratory so that the casts can be mounted on an articulator (Fig. 2B) and for the virtual design of the complete dentures with the software (Ceramill Mind/D-Flow; Amann Girrbach). In the dental laboratory, scan the definitive casts separately with an optical scanner (Ceramill Map400; Amann Girrbach) (Fig. 3A,B). Then, scan the casts and the occlusion rim positioned in the transfer stand (Ceramill Transferkit; Amann Girrbach) (Fig. 3C). Import the data into the software to design complete dentures (Ceramill Mind/D-Flow; Amann Girrbach). Mount the scanned maxillary and mandibular casts virtually according to the scanned occlusion rim. For this, superimpose the files digitally and combine them by means of best-fit matching (Fig. 4). Set the occlusal plane with the help of the occlusion rim (Fig. 5A) and analyze the casts with the help of the step-by-step instruction in the software. Mark the anatomic characteristics of the cast surfaces, the position of the first premolars, and the center line with the margin lines (Fig. 5B).
Figure 2. Occlusal record. A, Occlusion rims connected with registration paste (Superbite: zinc oxide eugenol bite registration paste; Harry J. Bosworth Co) and marked reference lines. B, Casts and occlusion rims mounted in articulator.
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Figure 4. Virtual mounting of casts by means of best-fit matching.
9. 10.
11.
12.
13.
Figure 3. Screenshots of scanned casts. A, Maxillary. B, Mandibular. C, Occlusion rim between casts.
Determine the boundary line for the anterior teeth on the basis of the maxillary record base. With the entered information, the software calculates the common arrangement lines and suggests an applicable set of artificial teeth (Fig. 5C). The deposited artificial teeth are conventionally manufactured teeth made of acrylic resin from different manufacturers and not produced by CAD/CAM technology. 7. Select the preferred artificial teeth and let the software automatically arrange them in their correct position (Fig. 5D). 8. Design the gingival parts of the dentures on the basis of the suggestion of the software with the Wimmer et al
14.
15. 16.
help of the different tools provided, for example, a virtual wax knife or paint brush (Fig. 5E). Send a preview of the virtual arrangement to the clinician for evaluation. Shorten the basal surfaces of the artificial teeth virtually according to the contour of the alveolar ridges and the minimum denture thickness and provide them with retention for later fixation in the denture bases. Generate the data sets for the denture bases and the tooth sockets. Mill the denture bases with a 5-axis milling machine from a gingiva-colored wax blank (Ceramill D-Wax, Ceramill Motion 2; Amann Girrbach). Modify the conventional denture teeth according to the individual clinical situation. For this, mount them in a special blank/device and mill their basal surfaces corresponding to the prior computation. (Ceramill Motion 2; Amann Girrbach). Wax the adapted denture teeth into the sockets of the wax bases (Fig. 6) and evaluate the completed trial denture in the conventional articulator (Fig. 7). Send the trial denture to the clinician. In the dental office, evaluate the trial dentures in the patient’s mouth. Make adjustments to the arrangement in the conventional way, if necessary. Send the trial dentures to the dental laboratory for their completion by flasking. Deliver the completed dentures (Fig. 8, 9).
DISCUSSION It has been 20 years since the implementation of CAD/ CAM technology in the fabrication of complete dentures was reported. In the last few years, significant advancements have taken place in this field, and the first case reports have been published.12,13 The presented concept of Ceramill Full Denture Workflow incorporates CAD/CAM technology into the workflow of fabricating complete dentures. However, incorporation refers only to the tooth arrangement, the THE JOURNAL OF PROSTHETIC DENTISTRY
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Figure 5. Digital workflow of designing complete dentures. A, Setting occlusal plane. B, Cast analysis. C, Proposal for tooth arrangement. D, Articulator settings. E, Proposal for gingival design. F, Milling data for maxillary complete denture including tooth sockets.
milling of the wax trial bases, and the modification of the denture teeth so that they can be inserted into the tooth sockets of the bases with wax and without additional grinding. Compared with the completely conventional technique of fabricating dentures, this procedure has several advantages. Scanning the maxillary and mandibular casts and importing them into the software allows for better detection and visualization of the morphology of the edentulous maxillary and mandibular arches. Virtual sectional views facilitate the identification of anatomic characteristics, and, with the help of a software algorithm, the midlines of the alveolar ridges, for example, can be identified. A further advantage is that the virtual THE JOURNAL OF PROSTHETIC DENTISTRY
arrangement of the artificial teeth is a reproducible procedure enabling predictable results. With the help of the virtual articulator, static occlusion and the dynamic relation of the dentures are considered during digital arrangement. Also, the digitized maxillary record base can be taken into account, particularly for anterior teeth arrangement. With the correct incisal edge position of the maxillary teeth, ideal lip support can be realized. Moreover, the maxillary record base will be used to establish the plane of occlusion. Posterior teeth can be arranged according to the occlusal concept of the manufacturer. Thus, an ideal contact situation can be achieved. The arrangement can be performed in significantly less time in comparison with the manual Wimmer et al
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2015
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Figure 6. Milled wax dentures. A, Maxillary upper surface with teeth inserted. B, Maxillary intaglio. C, Mandibular upper surface with teeth inserted. D, Mandibular intaglio.
Figure 7. Milled wax dentures in articulator. Figure 8. Completed dentures.
arrangement. Additionally, the time-consuming procedure of manual waxing is eliminated. The polished surfaces of the denture bases can be easily designed with different anatomic features, for example, stippling and rugae. A preview of the virtual arrangement can be sent to the clinician for approval. If modifications of the tooth arrangement are required, this is possible. Also, for example, for adjustments for esthetic reasons, the arrangement can be superimposed with the digitized record bases. Wimmer et al
At the trial placement, minor adjustments of the arrangement can be made in the conventional way. In case of extensive modification, the wax denture base can be milled once more according to the required arrangement, and a second evaluation appointment is possible. Indeed, in the presented patient case, increasing the vertical dimension of occlusion was necessary. The dental technician unscrewed the anterior guide pin and THE JOURNAL OF PROSTHETIC DENTISTRY
6
Volume
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Issue
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difficult and fault-prone. Development should focus on this field. Also, the problem concerning the durability of the bond between the base and the teeth has not been solved. Clinical and laboratory research is necessary to validate the new computer-aided treatment procedures for the fabrication of complete dentures.10 SUMMARY Incorporation of CAD/CAM technology into the design and fabrication of complete dentures helps to simplify laboratory work and standardize complete denture fabrication. Ceramill Full Denture Workflow is a CAD/ CAM-based system. With the help of proprietary software, the denture teeth can be arranged and bases designed. Dentures bases are milled from a wax blank, allowing for adjustments after clinical evaluation. REFERENCES
Figure 9. A, B, Patient with complete dentures.
remounted the mandibular cast in the articulator with the occlusion rim. As a facebow record had been made, increasing the vertical dimension did not entail errors in the occlusion. The situation was transferred into the virtual articulator, and a new mandibular tooth arrangement was designed with the software. The virtual design of complete dentures allows for consistent thickness of the bases. The material thickness can be adjusted to the material and kept minimal, allowing for the function and durability of the dentures. Furthermore, a consistent material thickness minimizes deviations in the contact relationships of the teeth, for example, due to polymerization shrinkage, and enables an improved fit to the mucosa, which is important for denture retention.16-18 The dentures may be easily duplicated with the digital data and research in this field is facilitated.10 With the system used here (Ceramill Full Denture Workflow), complete dentures can be digitally completed by milling them from prepolymerized acrylic resin blocks. However, the manufacturer does not currently enable this option because of the risk of remake. The source of error is the manual maxillomandibular relationship record, which is THE JOURNAL OF PROSTHETIC DENTISTRY
1. van Noort R. The future of dental devices is digital. Dent Mater 2012;28:3-12. 2. Busch M, Kordass B. Concept and development of a computerized positioning of prosthetic teeth for complete dentures. Int J Comput Dent 2006;9:113-20. 3. Kanazawa M, Inokoshi M, Minakuchi S, Ohbayashi N. Trial of a CAD/CAM system for fabricating complete dentures. Dent Mater J 2011;30:93-6. 4. Kawahata N, Ono H, Nishi Y, Hamano T, Nagaoka E. Trial of duplication procedure for complete dentures by CAD/CAM. J Oral Rehabil 1997;24:540-8. 5. Maeda Y, Minoura M, Tsutsumi S, Okada M, Nokubi T. A CAD/CAM system for removable denture. Part I: fabrication of complete dentures. Int J Prosthodont 1994;7:17-21. 6. Sun Y, Lu P, Wang Y. Study on CAD&RP for removable complete denture. Comput Methods Programs Biomed 2009;93:266-72. 7. Goodacre CJ, Garbacea A, Naylor WP, Daher T, Marchack CB, Lowry J. CAD/CAM fabricated complete dentures: concepts and clinical methods of obtaining required morphological data. J Prosthet Dent 2012; 107:34-46. 8. Zhang YD, Jiang JG, Liang T, Hu WP. Kinematics modeling and experimentation of the multi-manipulator tooth-arrangement robot for full denture manufacturing. Journal of medical systems 2011;35:1421-9. 9. Inokoshi M, Kanazawa M, Minakuchi S. Evaluation of a complete denture trial method applying rapid prototyping. Dent Mater J 2012;31: 40-6. 10. Bidra AS, Taylor TD, Agar JR. Computer-aided technology for fabricating complete dentures: systematic review of historical background, current status, and future perspectives. J Prosthet Dent 2013;109:361-6. 11. Lebon N, Tapie L, Vennat E, Mawussi B. Influence of CAD/CAM tool and material on tool wear and roughness of dental prostheses after milling. J Prosthet Dent 2015;114:236-47. 12. Infante L, Yilmaz B, McGlumphy E, Finger I. Fabricating complete dentures with CAD/CAM technology. J Prosthet Dent 2014;111:351-5. 13. Kattadiyil MT, Goodacre CJ, Baba NZ. CAD/CAM complete dentures: a review of two commercial fabrication systems. J Calif Dent Assoc 2013;41:407-16. 14. McLaughlin JB, Ramos V Jr. Complete denture fabrication with CAD/CAM record bases. J Prosthet Dent 2015;114:493-7. 15. Jacob RF. The traditional therapeutic paradigm: complete denture therapy. J Prosthet Dent 1998;79:6-13. 16. Artopoulos A, Juszczyk AS, Rodriguez JM, Clark RK, Radford DR. Threedimensional processing deformation of three denture base materials. J Prosthet Dent 2013;110:481-7. 17. Darvell BW, Clark RK. The physical mechanisms of complete denture retention. Br Dent J 2000;189:248-52. 18. Chen JC, Lacefield WR, Castleberry DJ. Effect of denture thickness and curing cycle on the dimensional stability of acrylic resin denture bases. Dent Mater 1988;4:20-4. Corresponding author: Dr Timea Wimmer Goethestraße 70, 80336 Munich GERMANY Email: [email protected] Copyright © 2015 by the Editorial Council for The Journal of Prosthetic Dentistry.
Wimmer et al