- Email: [email protected]
Maxillary complete-arch implant-supported restoration: A digital scanning and maxillomandibular relationship workflow
DENTAL TECHNIQUE
Maxillary complete-arch implant-supported restoration: A digital scanning and maxillomandibular relationship workflow Walaa Magdy Ahmed, BDS, MSc, Dip Pros, PhD, FRCD(C),a Tyler V. Verhaeghe, DDS, MEd,b and Anthony P. G. McCullagh, BDS, MPhil, MFD RCS Ire, MRD(Pros) RCS Edinc
The accuracy of intraoral scanABSTRACT ners, particularly compared Intraoral scanners are increasingly used as a replacement for conventional impressions, including with conventional impressions, the capturing of edentulous arches, although their use may be clinically challenging. This 1 has been well documented. technique article describes the fabrication and use of a custom scanning device to scaffold an Intraoral scanners have been intraoral complete-arch scan of at least 6 implant scan bodies in the edentulous maxilla while used as a replacement for consimultaneously capturing the maxillomandibular relationship for the purpose of establishing a digital workflow to fabricate a maxillary complete-arch implant-supported prosthesis. (J Prosthet ventional impressions to Dent 2020;-:---) restore as many as 10 units without extensive edentulous spans.1 Intraoral scanners have also been used to digitally intraoral scans for multiple implants in an edentulous arch capture edentulous arches, although the technique has include the visible length of the scan body, the distance and challenges.2 Scan retractors may be required, although this length of the scan, and the experience level and ability of the may result in distortion of the vestibles.3 The use of an operator to follow a set scan protocol.11 artificial landmark when scanning a long edentulous span Previously published digital dental techniques for has been reported to improve trueness and precision.4 A complete-arch restorations include using a hemisectioned complete-arch 3D-printed surgical guide with recent systematic review concluded that the use of digital occlusal registration material and scan bodies to fabricate technologies to scan an edentulous arch remains a clinical a definitive fixed restoration,12 as well as transferring the challenge.5 Investigations of intraoral scanning for multiple implantinformation digitally from interim to definitive fixed supported complete-arch prostheses have been limited to restoration.13 Given the difficulty that may be encoun6-8 in vitro studies. Intraoral scanning of complete-arch tered with obtaining an accurate intraoral scan for a multiple implants has been reported to be either not complete-arch restoration, an auxiliary polymeric device, simulating a denture, has been used.14 This technique different than6 or more accurate than7 conventional impressions by using the splinted open-tray technique. article describes the fabrication and use of a custom Moreover, the type of intraoral scanner has been found to scanning device (CSD) to scaffold an intraoral completeaffect the accuracy of digitally capturing dental arches with arch scan of at least 6 implant scan bodies in the multiple implants.8,9 The accuracy of an aluminum frameedentulous maxilla while simultaneously capturing the work fabricated after the use of an intraoral scanner has maxillomandibular relationship for the purpose of reported good passive fit even with tilted implants.10 Other establishing a digital workflow to fabricate a maxillary factors that have been shown to affect the accuracy of complete-arch implantesupported restoration. W.M.A. received financial support from the Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia as an educational scholarship. This technique was presented in the case presentation poster competition at the American College of Prosthodontists Annual Meeting 2019, Miami, FL, and received the third-place award. a Graduate student, Prosthodontics, Faculty of Dentistry, University of British Columbia, Vancouver, Canada; Lecturer, Department of Restorative and Aesthetic Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia. b Graduate student, Graduate Prosthodontics, Prosthodontics, Faculty of Dentistry, University of British Columbia, Vancouver, Canada. c Clinical Associate Professor, Graduate Prosthodontics, Prosthodontics, Faculty of Dentistry, University of British Columbia, Vancouver, Canada.
THE JOURNAL OF PROSTHETIC DENTISTRY
1
2
Volume
-
Issue
-
Figure 1. Software design of custom scanning device to be used during complete-arch intraoral scan.
Figure 2. Custom scanning device printed using resin-based material.
TECHNIQUE 1. Fabricate a CSD to be used during the completearch digital scan by first duplicating the maxillary complete denture by using a desktop scanner (Desktop scanner D800; 3Shape Inc). Export the scan to a standard tessellation language file and then import it into editing software (Rhinoceros 5.0
THE JOURNAL OF PROSTHETIC DENTISTRY
Figure 3. Intraoral scan of maxillary arch with custom scanning device, mandibular arch, and maxillomandibular relationship.
for PC; Robert McNeel & Associates). Cut 3 windows into the CSD to reveal sufficient areas of soft tissue to be used as a stitching reference during scanning. Make sure not to make the windows overly large to compromise the retention, stability, or support of the CSD. The windows can be created by subtracting solid shapes from the standard tessellation language file. Keep tripod landmarks on Ahmed et al
-
2020
3
Figure 4. Maxillary complete-arch intraoral scan. A, After digitally trimming custom scanning device and rescanning corresponding areas of soft tissue and implant platforms. B, Maxillomandibular relationship record.
Figure 5. Scanned implant platforms digitally trimmed from soft tissue scan.
the CSD and on the anterior and bilaterally posteriorly to facilitate scanning of the maxillomandibular relationship (Fig. 1). 2. Print the CSD using a resin-based 3D printer (Form 2 printer; Formlabs Inc) (Fig. 2). The CSD can also be fabricated by using the traditional duplication technique and cutting the 3 windows manually. 3. Remove the healing abutments and seat the CSD onto the patient’s maxillary arch. Intraorally, evaluate the occlusion for any interferences and the buccal flanges for any overextensions and adjust as necessary. Apply a small amount of denture adhesive (Poligrip Denture Adhesive Powder; GlaxoSmithKline Consumer Healthcare Inc) to the intaglio surface of the CSD in the areas of the palate and alveolar ridges not exposed by the windows and ensures complete seating. 4. Create the first order to be a “study model” and then intraorally scan the maxillary arch with the CSD, the mandibular arch, and the maxillomandibular relationship by using the intraoral scanner (TRIOS 3; 3Shape Inc) (Fig. 3).
Ahmed et al
Figure 6. Soft tissue scan locked at digitally trimmed areas of implant platforms.
5. Create the second order by duplicating the first order as a “preparation copy” and then modifying it as an implant order. 6. Remove the CSD from the patient’s mouth. Sequentially, digitally trim the CSD and rescan the soft tissue and implant platforms until a maxillary complete-arch intraoral scan of the soft tissue is completed (Fig. 4). 7. Intraorally, seat the implant scan bodies and confirm that they are completely seated with radiographs. Digitally trim the scanned implant platforms from the soft tissue scan (Fig. 5) and then lock to the implant order scan (Fig. 6). Intraorally, scan the scan bodies (Fig. 7). 8. Verify the complete-arch scan of the maxillary implant scan bodies by superimposing them to the scan body library (Fig. 8). DISCUSSION Obtaining a complete-arch soft tissue scan can be difficult,5 and a lack of adequately described techniques2 is
THE JOURNAL OF PROSTHETIC DENTISTRY
4
Volume
-
Issue
-
Figure 7. Intraoral scan of all 6 scan bodies showing. A, Maxillary arch. B, Maxillomandibular relationship record.
Figure 8. Each scanned scan body superimposed to scan body library to verify complete-arch intraoral scan. Example shows scan body at left maxillary lateral incisor location.
therefore expected. This may be improved with the fabrication and use of a CSD. Its fabrication requires an existing accurately fitting immediate or definitive complete denture, a working knowledge of 3D editing software, and access to a resin-based 3D printer. However, once fabricated, the CSD provides landmarks to facilitate intraoral scanning while also recording the maxillomandibular relationship. Its use may reduce the number of clinical steps required, therefore saving chair time.
THE JOURNAL OF PROSTHETIC DENTISTRY
Balancing the size of the CSD windows is important. CSD should allow for scanning sufficient areas of soft tissue to be used as a stitching reference without having too large windows that would affect the retention, stability, and support. Also, the use of excessive denture adhesive may affect the soft tissue scan. The presented technique can be applied to clinical situations with 4 or more implants. Locking the soft tissue during the second order implant scan helps keep the soft tissue landmarks around the healing abutments Ahmed et al
-
2020
unchanged during the process of stitching the scan “without scan bodies” to the one “with scan bodies.” A higher scan accuracy would be expected when the number of implants is increased from 6 to 8, for example, because there would be more soft tissue landmarks available. The technique as outlined can also provide an accurate verification of the passive fit of the scan bodies by digitally superimposing them to the implant scan body library. Although significant time can be saved by following the described implant scan protocol, there is a need to perform 2 scan orders instead of one. Another limitation is that this digital scan protocol requires close collaboration with a digitally equipped dental laboratory or possession of the required software and 3D printer by the practitioner. Thus, there are purchasing and managing costs as well as a learning curve. SUMMARY This article describes the fabrication and use of a CSD as a scaffold for intraorally scanning an edentulous maxilla with at least 6 implant scan bodies and simultaneously recording the maxillomandibular relationship to fabricate a maxillary complete-arch implantesupported restoration using a digital workflow. This technique provides the intraoral scanner with anatomic landmarks to improve the likelihood of scanning efficiency and offers a possible scan protocol which may help improve the accuracy of the scan. REFERENCES 1. Nedelcu R, Olsson P, Nyström I, Rydén J, Thor A. Accuracy and precision of 3 intraoral scanners and accuracy of conventional impressions: A novel in vivo analysis method. J Dent 2018;69:110-8. 2. Lo Russo L, Caradonna G, Troiano G, Salamini A, Guida L, Ciavarella D. Threedimensional differences between intraoral scans and conventional impressions of edentulous jaws: A clinical study. J Prosthet Dent 2020;123:264-8.
Ahmed et al
5
3. Fang J, An X, Jeong S, Choi B. Development of complete dentures based on digital intraoral impressions-Case report. J Prosthodont Res 2018;62:116-20. 4. Kim J, Amelya A, Shin Y, Shim J. Accuracy of intraoral digital impressions using an artificial landmark. J Prosthet Dent 2017;117:755-61. 5. Bohner L, Gamba DD, Hanisch M, Marcio BS, Tortamano Neto P, Lagana DC, et al. Accuracy of digital technologies for the scanning of facial, skeletal, and intraoral tissues: A systematic review. J Prosthet Dent 2019;121: 246-51. 6. Papaspyridakos P, Gallucci G, Chen C, Hanssen S, Naert I, Vandenberghe B. Digital versus conventional implant impressions for edentulous patients: Accuracy outcomes. Clin Oral Implants Res 2016;27:465-72. 7. Amin S, Weber H, Finkelman M, El Rafie K, Kudara Y, Papaspyridakos P. Digital vs. conventional full-arch implant impressions: A comparative study. Clin Oral Implants Res 2017;28:1360-7. 8. Vandeweghe S, Vervack V, Dierens M, De Bruyn H. Accuracy of digital impressions of multiple dental implants: An in vitro study. Clin Oral Implants Res 2017;28:648-53. 9. Di Fiore A, Meneghello R, Graiff L, Savio G, Vigolo P, Monaco C, et al. Full arch digital scanning systems performances for implant-supported fixed dental prostheses: A comparative study of 8 intraoral scanners. J Prosthodont Res 2019;63:396-403. 10. Pesce P, Pera F, Setti P, Menini M. Precision and accuracy of a digital impression scanner in full-arch implant rehabilitation. Int J Prosthodont 2018;31:171-5. 11. Gimenez-Gonzalez B, Hassan B, Özcan M, Pradies G. An in vitro study of factors influencing the performance of digital intraoral impressions operating on active wavefront sampling technology with multiple implants in the edentulous maxilla. J Prosthodont 2017;26:650-5. 12. Michelinakis G, Nikolidakis D. Using the surgical guide for impression-free digital bite registration in the edentulous maxilla e a technical note. Int J Imp Dent 2019 2019;5:19. 13. An X, Fang J, Jeong S, Choi B. A CAD-CAM technique for conversion of interim-to-definitive restoration in patients with complete edentulism. J Prosthet Dent 2018;120:190-3. 14. Iturrate M, Minguez R, Pradies G, Solaberrieta E. Obtaining reliable intraoral digital scans for an implant-supported complete-arch prosthesis: A dental technique. J Prosthet Dent 2019;121:237-41. Corresponding author: Dr Walaa Magdy Ahmed Faculty of Dentistry, University of British Columbia 2199 Wesbrook Mall Vancouver, BC V6T 1Z3 CANADA Email: [email protected] Acknowledgments The authors would like to thank Mr Jae Won Sim B.I.D at Paul Ro Dental Laboratory, Vancouver, Canada, for performing the dental laboratory steps. Copyright © 2020 by the Editorial Council for The Journal of Prosthetic Dentistry. https://doi.org/10.1016/j.prosdent.2020.01.010
THE JOURNAL OF PROSTHETIC DENTISTRY
Maxillary complete-arch implant-supported restoration: A digital scanning and maxillomandibular relationship workflow Walaa Magdy Ahmed, BDS, MSc, Dip Pros, PhD, FRCD(C),a Tyler V. Verhaeghe, DDS, MEd,b and Anthony P. G. McCullagh, BDS, MPhil, MFD RCS Ire, MRD(Pros) RCS Edinc
The accuracy of intraoral scanABSTRACT ners, particularly compared Intraoral scanners are increasingly used as a replacement for conventional impressions, including with conventional impressions, the capturing of edentulous arches, although their use may be clinically challenging. This 1 has been well documented. technique article describes the fabrication and use of a custom scanning device to scaffold an Intraoral scanners have been intraoral complete-arch scan of at least 6 implant scan bodies in the edentulous maxilla while used as a replacement for consimultaneously capturing the maxillomandibular relationship for the purpose of establishing a digital workflow to fabricate a maxillary complete-arch implant-supported prosthesis. (J Prosthet ventional impressions to Dent 2020;-:---) restore as many as 10 units without extensive edentulous spans.1 Intraoral scanners have also been used to digitally intraoral scans for multiple implants in an edentulous arch capture edentulous arches, although the technique has include the visible length of the scan body, the distance and challenges.2 Scan retractors may be required, although this length of the scan, and the experience level and ability of the may result in distortion of the vestibles.3 The use of an operator to follow a set scan protocol.11 artificial landmark when scanning a long edentulous span Previously published digital dental techniques for has been reported to improve trueness and precision.4 A complete-arch restorations include using a hemisectioned complete-arch 3D-printed surgical guide with recent systematic review concluded that the use of digital occlusal registration material and scan bodies to fabricate technologies to scan an edentulous arch remains a clinical a definitive fixed restoration,12 as well as transferring the challenge.5 Investigations of intraoral scanning for multiple implantinformation digitally from interim to definitive fixed supported complete-arch prostheses have been limited to restoration.13 Given the difficulty that may be encoun6-8 in vitro studies. Intraoral scanning of complete-arch tered with obtaining an accurate intraoral scan for a multiple implants has been reported to be either not complete-arch restoration, an auxiliary polymeric device, simulating a denture, has been used.14 This technique different than6 or more accurate than7 conventional impressions by using the splinted open-tray technique. article describes the fabrication and use of a custom Moreover, the type of intraoral scanner has been found to scanning device (CSD) to scaffold an intraoral completeaffect the accuracy of digitally capturing dental arches with arch scan of at least 6 implant scan bodies in the multiple implants.8,9 The accuracy of an aluminum frameedentulous maxilla while simultaneously capturing the work fabricated after the use of an intraoral scanner has maxillomandibular relationship for the purpose of reported good passive fit even with tilted implants.10 Other establishing a digital workflow to fabricate a maxillary factors that have been shown to affect the accuracy of complete-arch implantesupported restoration. W.M.A. received financial support from the Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia as an educational scholarship. This technique was presented in the case presentation poster competition at the American College of Prosthodontists Annual Meeting 2019, Miami, FL, and received the third-place award. a Graduate student, Prosthodontics, Faculty of Dentistry, University of British Columbia, Vancouver, Canada; Lecturer, Department of Restorative and Aesthetic Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia. b Graduate student, Graduate Prosthodontics, Prosthodontics, Faculty of Dentistry, University of British Columbia, Vancouver, Canada. c Clinical Associate Professor, Graduate Prosthodontics, Prosthodontics, Faculty of Dentistry, University of British Columbia, Vancouver, Canada.
THE JOURNAL OF PROSTHETIC DENTISTRY
1
2
Volume
-
Issue
-
Figure 1. Software design of custom scanning device to be used during complete-arch intraoral scan.
Figure 2. Custom scanning device printed using resin-based material.
TECHNIQUE 1. Fabricate a CSD to be used during the completearch digital scan by first duplicating the maxillary complete denture by using a desktop scanner (Desktop scanner D800; 3Shape Inc). Export the scan to a standard tessellation language file and then import it into editing software (Rhinoceros 5.0
THE JOURNAL OF PROSTHETIC DENTISTRY
Figure 3. Intraoral scan of maxillary arch with custom scanning device, mandibular arch, and maxillomandibular relationship.
for PC; Robert McNeel & Associates). Cut 3 windows into the CSD to reveal sufficient areas of soft tissue to be used as a stitching reference during scanning. Make sure not to make the windows overly large to compromise the retention, stability, or support of the CSD. The windows can be created by subtracting solid shapes from the standard tessellation language file. Keep tripod landmarks on Ahmed et al
-
2020
3
Figure 4. Maxillary complete-arch intraoral scan. A, After digitally trimming custom scanning device and rescanning corresponding areas of soft tissue and implant platforms. B, Maxillomandibular relationship record.
Figure 5. Scanned implant platforms digitally trimmed from soft tissue scan.
the CSD and on the anterior and bilaterally posteriorly to facilitate scanning of the maxillomandibular relationship (Fig. 1). 2. Print the CSD using a resin-based 3D printer (Form 2 printer; Formlabs Inc) (Fig. 2). The CSD can also be fabricated by using the traditional duplication technique and cutting the 3 windows manually. 3. Remove the healing abutments and seat the CSD onto the patient’s maxillary arch. Intraorally, evaluate the occlusion for any interferences and the buccal flanges for any overextensions and adjust as necessary. Apply a small amount of denture adhesive (Poligrip Denture Adhesive Powder; GlaxoSmithKline Consumer Healthcare Inc) to the intaglio surface of the CSD in the areas of the palate and alveolar ridges not exposed by the windows and ensures complete seating. 4. Create the first order to be a “study model” and then intraorally scan the maxillary arch with the CSD, the mandibular arch, and the maxillomandibular relationship by using the intraoral scanner (TRIOS 3; 3Shape Inc) (Fig. 3).
Ahmed et al
Figure 6. Soft tissue scan locked at digitally trimmed areas of implant platforms.
5. Create the second order by duplicating the first order as a “preparation copy” and then modifying it as an implant order. 6. Remove the CSD from the patient’s mouth. Sequentially, digitally trim the CSD and rescan the soft tissue and implant platforms until a maxillary complete-arch intraoral scan of the soft tissue is completed (Fig. 4). 7. Intraorally, seat the implant scan bodies and confirm that they are completely seated with radiographs. Digitally trim the scanned implant platforms from the soft tissue scan (Fig. 5) and then lock to the implant order scan (Fig. 6). Intraorally, scan the scan bodies (Fig. 7). 8. Verify the complete-arch scan of the maxillary implant scan bodies by superimposing them to the scan body library (Fig. 8). DISCUSSION Obtaining a complete-arch soft tissue scan can be difficult,5 and a lack of adequately described techniques2 is
THE JOURNAL OF PROSTHETIC DENTISTRY
4
Volume
-
Issue
-
Figure 7. Intraoral scan of all 6 scan bodies showing. A, Maxillary arch. B, Maxillomandibular relationship record.
Figure 8. Each scanned scan body superimposed to scan body library to verify complete-arch intraoral scan. Example shows scan body at left maxillary lateral incisor location.
therefore expected. This may be improved with the fabrication and use of a CSD. Its fabrication requires an existing accurately fitting immediate or definitive complete denture, a working knowledge of 3D editing software, and access to a resin-based 3D printer. However, once fabricated, the CSD provides landmarks to facilitate intraoral scanning while also recording the maxillomandibular relationship. Its use may reduce the number of clinical steps required, therefore saving chair time.
THE JOURNAL OF PROSTHETIC DENTISTRY
Balancing the size of the CSD windows is important. CSD should allow for scanning sufficient areas of soft tissue to be used as a stitching reference without having too large windows that would affect the retention, stability, and support. Also, the use of excessive denture adhesive may affect the soft tissue scan. The presented technique can be applied to clinical situations with 4 or more implants. Locking the soft tissue during the second order implant scan helps keep the soft tissue landmarks around the healing abutments Ahmed et al
-
2020
unchanged during the process of stitching the scan “without scan bodies” to the one “with scan bodies.” A higher scan accuracy would be expected when the number of implants is increased from 6 to 8, for example, because there would be more soft tissue landmarks available. The technique as outlined can also provide an accurate verification of the passive fit of the scan bodies by digitally superimposing them to the implant scan body library. Although significant time can be saved by following the described implant scan protocol, there is a need to perform 2 scan orders instead of one. Another limitation is that this digital scan protocol requires close collaboration with a digitally equipped dental laboratory or possession of the required software and 3D printer by the practitioner. Thus, there are purchasing and managing costs as well as a learning curve. SUMMARY This article describes the fabrication and use of a CSD as a scaffold for intraorally scanning an edentulous maxilla with at least 6 implant scan bodies and simultaneously recording the maxillomandibular relationship to fabricate a maxillary complete-arch implantesupported restoration using a digital workflow. This technique provides the intraoral scanner with anatomic landmarks to improve the likelihood of scanning efficiency and offers a possible scan protocol which may help improve the accuracy of the scan. REFERENCES 1. Nedelcu R, Olsson P, Nyström I, Rydén J, Thor A. Accuracy and precision of 3 intraoral scanners and accuracy of conventional impressions: A novel in vivo analysis method. J Dent 2018;69:110-8. 2. Lo Russo L, Caradonna G, Troiano G, Salamini A, Guida L, Ciavarella D. Threedimensional differences between intraoral scans and conventional impressions of edentulous jaws: A clinical study. J Prosthet Dent 2020;123:264-8.
Ahmed et al
5
3. Fang J, An X, Jeong S, Choi B. Development of complete dentures based on digital intraoral impressions-Case report. J Prosthodont Res 2018;62:116-20. 4. Kim J, Amelya A, Shin Y, Shim J. Accuracy of intraoral digital impressions using an artificial landmark. J Prosthet Dent 2017;117:755-61. 5. Bohner L, Gamba DD, Hanisch M, Marcio BS, Tortamano Neto P, Lagana DC, et al. Accuracy of digital technologies for the scanning of facial, skeletal, and intraoral tissues: A systematic review. J Prosthet Dent 2019;121: 246-51. 6. Papaspyridakos P, Gallucci G, Chen C, Hanssen S, Naert I, Vandenberghe B. Digital versus conventional implant impressions for edentulous patients: Accuracy outcomes. Clin Oral Implants Res 2016;27:465-72. 7. Amin S, Weber H, Finkelman M, El Rafie K, Kudara Y, Papaspyridakos P. Digital vs. conventional full-arch implant impressions: A comparative study. Clin Oral Implants Res 2017;28:1360-7. 8. Vandeweghe S, Vervack V, Dierens M, De Bruyn H. Accuracy of digital impressions of multiple dental implants: An in vitro study. Clin Oral Implants Res 2017;28:648-53. 9. Di Fiore A, Meneghello R, Graiff L, Savio G, Vigolo P, Monaco C, et al. Full arch digital scanning systems performances for implant-supported fixed dental prostheses: A comparative study of 8 intraoral scanners. J Prosthodont Res 2019;63:396-403. 10. Pesce P, Pera F, Setti P, Menini M. Precision and accuracy of a digital impression scanner in full-arch implant rehabilitation. Int J Prosthodont 2018;31:171-5. 11. Gimenez-Gonzalez B, Hassan B, Özcan M, Pradies G. An in vitro study of factors influencing the performance of digital intraoral impressions operating on active wavefront sampling technology with multiple implants in the edentulous maxilla. J Prosthodont 2017;26:650-5. 12. Michelinakis G, Nikolidakis D. Using the surgical guide for impression-free digital bite registration in the edentulous maxilla e a technical note. Int J Imp Dent 2019 2019;5:19. 13. An X, Fang J, Jeong S, Choi B. A CAD-CAM technique for conversion of interim-to-definitive restoration in patients with complete edentulism. J Prosthet Dent 2018;120:190-3. 14. Iturrate M, Minguez R, Pradies G, Solaberrieta E. Obtaining reliable intraoral digital scans for an implant-supported complete-arch prosthesis: A dental technique. J Prosthet Dent 2019;121:237-41. Corresponding author: Dr Walaa Magdy Ahmed Faculty of Dentistry, University of British Columbia 2199 Wesbrook Mall Vancouver, BC V6T 1Z3 CANADA Email: [email protected] Acknowledgments The authors would like to thank Mr Jae Won Sim B.I.D at Paul Ro Dental Laboratory, Vancouver, Canada, for performing the dental laboratory steps. Copyright © 2020 by the Editorial Council for The Journal of Prosthetic Dentistry. https://doi.org/10.1016/j.prosdent.2020.01.010
THE JOURNAL OF PROSTHETIC DENTISTRY