- Email: [email protected]
A digital guiding device to facilitate cementation of porcelain laminate veneers
DENTAL TECHNIQUE
A digital guiding device to facilitate cementation of porcelain laminate veneers Xi Chen, DDS, PhD,a Nan Zhou, DDS, MS,b Meng Ding, DDS, MS,c Jianlong Jing, BSc,d Qi Xi, DDS,e and Guofeng Wu, DDS, PhDf Success and longevity of porABSTRACT celain laminate veneers (PLVs) This article presents a computer-aided design and computer-aided manufacturing (CAD-CAM) rely primarily on proper guiding device to facilitate the simultaneous preconditioning and cementation of multiunit cementation with adhesive porcelain laminate veneers (PLVs). The guiding device was designed from the digital cast of the luting materials for retention PLVs and definitive cast assembly, with gingival margins 2 mm from the PLV margins and lingual and strength.1-3 Currently, the perforations and milled from a transparent polymethyl methacrylate (PMMA) disk. The PLVs were seated in the guiding device during the preconditioning procedures and transferred to the cementation of PLVs is abutment teeth with luting cement loaded on the intaglio surfaces. Excess resin cement was accomplished freehand and removed while the guiding device held the PLVs in place. This technique provides predictable, involves technique-sensitive accurate, and efficient simultaneous preconditioning and cementing of PLVs. (J Prosthet Dent procedures. PLVs are difficult 2019;-:---) to hold during the preoutcome is needed. Guiding devices have been used to conditioning procedures of hydrofluoric acid etching and facilitate implant placement,6,7 fenestration of maxillary silanization. A silicone cube technique was introduced as 4 sinus,8 gingivoplasty and alveolectomy,9 and orthodontic a safe holder for adjusting indirect prostheses. However, it is not applicable for PLVs given the fragile nature of brackets, placement of which have been reported to be these thin prostheses. Moreover, without a distinct predictable and reproducible.10-12 Computer-aided design of the guiding devices based on 3D imaging enmargin or seat on the PLV abutment teeth, detecting ables precise planning and implementation of the treatmisplacement of the PLV is difficult when excess bonding ment procedures while reducing operation time and resin covers the margins. A wooden spring clip technique complications.13-15 This technique report introduced a was described to facilitate the PLV cementation.5 Howdigitalized strategy for simultaneous preconditioning and ever, for this method, each spring clip needed to be recementing multiple PLVs by using a computer-aided contoured to achieve reliable adaptation and to maintain stability, and the PLVs were still placed onto abutment design and computer-aided manufactured (CAD-CAM) teeth by hand, so misplacement may occur. guiding device. The technique is described on a patient receiving 6 PLVs to improve esthetics affected by dental A method involving simultaneous placement of fluorosis. multiunit PLVs with a reliable and predictable clinical
This dental technique report was supported by the Key Medical Talents Project of Jiangsu Province (ZDRCC2016017). X.C. and N.Z. contributed equally to the work and should be regarded as joint first authors. a Attending Physician, Department of Prosthodontics, Stomatological Digital Engineering Center, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China. b Associate Chief Physician, Department of Endodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China. c Attending Physician, Department of Endodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China. d Senior Associate Technician, Department of Dental Laboratory, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China. e Resident and Master Degree Candidate, Department of Prosthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China. f Associate Professor, Department of Prosthodontics, Stomatological Digital Engineering Center, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China.
THE JOURNAL OF PROSTHETIC DENTISTRY
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Figure 1. Preoperative scan of maxillary dentition.
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Figure 2. Porcelain laminate veneers fitted on 3D printed definitive cast.
Figure 3. CAD-CAM guiding device. A, Design of guiding device with labial margin 2 mm from veneer margin. B, Perforations provided on lingual surfaces of guiding device. C, Guiding device after milling procedure. D, Definitive guiding device. CAD-CAM, computer-aided design and computer-aided manufacturing.
TECHNIQUE 1. Make an intraoral scan (TRIOS; 3Shape A/S) to obtain digital data of the teeth before treatment (Fig. 1). Prepare the teeth and scan these and the opposing arch, transform the scans to standard tessellation language (STL) file format, and input to a 3D printer THE JOURNAL OF PROSTHETIC DENTISTRY
(ProJet MJP 3600; 3D System) to print the definitive cast. 2. Design the PLVs in a dental CAD software program (3Shape Dental System; 3Shape A/S). Mill the PLVs from lithium disilicate ceramic blocks (IPS e.max CAD; Ivoclar Vivadent AG) by using a milling system (DWX-4W;
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Figure 4. Laboratory and clinical evaluation. A, PLVs seated in guiding device. B, PLVs simultaneously fitted to definitive cast facilitated by guiding device. C, PLVs fitted to abutment teeth by guiding device. D, Occlusal view of guiding device. PLVs, porcelain laminate veneers.
Roland DG Corp). Accurately fit the PLVs on the definitive cast (Fig. 2) and digitalize them by using a desktop scanner (D2000; 3Shape A/S) to obtain an STL file of the PLVs and definitive cast assembly. 3. Design the guiding device on the digital cast of the PLVs and definitive cast, with the labial cervical margin 2 mm short of the margins of the PLVs. Provide lingual perforations on all the abutment teeth. Adjust the path of insertion of the guide to eliminate unwanted undercuts and block the remaining undercuts. Set the thickness to approximately 1.5 mm to ensure the guiding device has adequate strength while providing sufficient flexibility to allow for easy insertion and removal (Fig. 3A, 3B). Extend the guiding device to the first premolars for stable retention. Mill the guiding device from a polymethyl methacrylate (PMMA) disk (Zenotec PMMA Cast; Wieland Dental) by using a milling system (Zenotec Select Ion; Wieland Dental) (Fig. 3C, 3D). 4. Insert the PLVs into the guiding device (Fig. 4A) and first evaluate the device loaded with PLVs on the definitive cast (Fig. 4B). Then, determine the ease of insertion, fit, retention, and stability of the guiding device intraorally on the abutment teeth. Also examine marginal fit and complete seating of the PLVs (Fig. 4C, 4D).
Chen et al
Figure 5. Silane applied to porcelain laminate veneers seated in guiding device.
5. Seat the PLVs into the guiding device after the etching procedure and apply the silane coupling agent (BIS-Silane Part A & B; BISCO Dental) to the intaglio surfaces (Fig. 5) according to the manufacturer’s instructions. 6. Etch (Uni-Etch w/BAC; BISCO Dental) the prepared teeth according to the manufacturer’s instructions.
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Figure 6. Cemented porcelain laminate veneers. A, Frontal view. B, Occlusal view.
7. Load an appropriate amount of resin luting cement (Choice 2 Veneer Cement; BISCO Dental) onto the intaglio surface of the PLVs seated in the guiding device. Gently place the guiding device with PLVs onto the abutment teeth, carefully evaluating the marginal fit with an explorer. Light-polymerize the resin luting cement through the transparent guide for 1 or 2 seconds, tack polymerize the excess cement beyond the gingival margins and lingual perforations, and then use a sharp scalpel to remove the excess gel-like cement in a parallel-to-margin motion. Gently remove the guiding device. Carefully pull dental floss through the interproximal contacts to remove any residual cement. Reevaluate for marginal fit and any residual cement in the marginal and interproximal regions. 8. Complete the polymerization of resin luting cement from the lingual, incisal, and labial directions. Evaluate the esthetics and adjust the occlusion of the PLVs, followed by definitive polishing (Fig. 6). DISSCUSSION The traditional freehand PLV cementation method is technique-sensitive. Errors may occur, especially in the preconditioning process and the fitting of PLVs with finger pressure, resulting in compromised restoration outcomes. The repetitive bonding operations for multiunit PLVs increase the risk for complications, with lengthened chairside time and poor patient experience. The presented technique that facilitates PLV cementation with improved accuracy was partially inspired by the indirect bracket bonding technique used in orthodontics.10-12 To effectively remove excess cement and to confirm the complete seating of PLVs, a 2-mm gap was designed from the PLV margins together with lingual perforations. Thus, excess resin cement flows through the labial gap and the lingual perforations, while the guide hold the PLVs in place, facilitating the process. The thickness of the guiding device was set to 1.5 mm, which allowed for flexibility while maintaining
THE JOURNAL OF PROSTHETIC DENTISTRY
adequate strength. The path of insertion was set to an incisal to gingival direction, with undercuts eliminated so that the guiding device could be easily inserted and removed from the prepared teeth without exerting pressure. The choice of transparent PMMA material allowed for direct light polymerization without the need to remove the guiding device and also enabled direct observation of the positioning and seating condition of PLVs. SUMMARY This report describes a CAD-CAM guiding device for the simultaneous preconditioning and cementation of multiunit PLVs. In contrast with the conventional method, this technique provides a predictable, accurate, and effective way of preconditioning and cementing PLVs. Although additional laboratory work is required for the guiding device, chairside time should be reduced with improved accuracy. Clinical studies are needed to evaluate quantitatively the efficacy and accuracy of the presented technique. REFERENCES 1. Arif R, Dennison JB, Garcia D, Yaman P. Retrospective evaluation of the clinical performance and longevity of porcelain laminate veneers 7 to 14 years after cementation. J Prosthet Dent 2019;122:31-7. 2. Dumfahrt H, Schaffer H. Porcelain laminate veneers. A retrospective evaluation after 1 to 10 years of service: part II clinical results. Int J Prosthodont 2000;13:9-18. 3. Addison O, Fleming GJP. The influence of cement lute, thermocycling and surface preparation on the strength of a porcelain laminate veneering material. Dent Mater 2004;20:286-92. 4. Afrashtehfar KI, Buser D, Belser UC. A safe holder for adjusting indirect prostheses: the silicone cube technique. J Prosthet Dent 2018;120:313-5. 5. Ra’fat IF, Aldhafeeri AF, Alogaili RS. A technique to facilitate ceramic veneer cementation. J Prosthet Dent 2018;20:194-7. 6. Fortin T, Champleboux G, Lormée J, Coudert JL. Precise dental implant placement in bone using surgical guides in conjunction with medical imaging techniques. J Oral Implantol 2000;26:300-3. 7. Becker CM, Kaiser DA. Surgical guide for dental implant placement. J Prosthet Dent 2000;83:248-51. 8. Goodacre BJ, Swamidass RS, Lozada J, Al-Ardah A, Sahl EA. 3D-printed guide for lateral approach sinus grafting: a dental technique. J Prosthet Dent 2018;119:897-901.
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9. Liu X, Yu J, Zhou J, Tan JG. A digitally guided dual technique for both gingival and bone resection during crown lengthening surgery. J Prosthet Dent 2018;119:345-9. 10. Castilla AE, Crowe JJ, Moses JR, Wang M, Ferracane JL, Covell DA Jr. Measurement and comparison of bracket transfer accuracy of five indirect bonding techniques. Angle Orthod 2014;84:607-14. 11. Nichols DA, Gardner G, Carballeyra AD. Reproducibility of bracket positioning in the indirect bonding technique. Am J Orthod Dentofacial Orthop 2013;144:770-6. 12. Brown MW, Koroluk L, Ko CC, Zhang K, Chen M, Nguyen T. Effectiveness and efficiency of a CAD/CAM orthodontic bracket system. Am J Orthod Dentofacial Orthop 2015;148:1067-74. 13. Nokar S, Moslehifard E, Bahman T, Bayanzadeh M, Nasirpouri F, Nokar A. Accuracy of implant placement using a CAD/CAM surgical guide: an in vitro study. Int J Oral Maxillofac Implants 2011;26:520-6. 14. Pettersson A, Kero T, Gillot L, Cannas B, Fäldt J, Söderberg R, et al. Accuracy of CAD/CAM-guided surgical template implant surgery on human cadavers: part I. J Prosthet Dent 2010;103:334-42.
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15. Cassetta M, Giansanti M, Di Mambro A, Calasso S, Barbato E. Minimally invasive corticotomy in orthodontics using a three-dimensional printed CAD/ CAM surgical guide. Int J Oral Maxillofac Surg 2016;45:1059-64. Corresponding author: Dr Guofeng Wu Department of Prosthodontics Stomatological Digital Engineering Center Nanjing Stomatological Hospital Medical School of Nanjing University 30 Zhongyang Road, Xuanwu District Nanjing, Jiangsu Province PR CHINA Email: [email protected] Copyright © 2019 by the Editorial Council for The Journal of Prosthetic Dentistry. https://doi.org/10.1016/j.prosdent.2019.10.011
THE JOURNAL OF PROSTHETIC DENTISTRY
A digital guiding device to facilitate cementation of porcelain laminate veneers Xi Chen, DDS, PhD,a Nan Zhou, DDS, MS,b Meng Ding, DDS, MS,c Jianlong Jing, BSc,d Qi Xi, DDS,e and Guofeng Wu, DDS, PhDf Success and longevity of porABSTRACT celain laminate veneers (PLVs) This article presents a computer-aided design and computer-aided manufacturing (CAD-CAM) rely primarily on proper guiding device to facilitate the simultaneous preconditioning and cementation of multiunit cementation with adhesive porcelain laminate veneers (PLVs). The guiding device was designed from the digital cast of the luting materials for retention PLVs and definitive cast assembly, with gingival margins 2 mm from the PLV margins and lingual and strength.1-3 Currently, the perforations and milled from a transparent polymethyl methacrylate (PMMA) disk. The PLVs were seated in the guiding device during the preconditioning procedures and transferred to the cementation of PLVs is abutment teeth with luting cement loaded on the intaglio surfaces. Excess resin cement was accomplished freehand and removed while the guiding device held the PLVs in place. This technique provides predictable, involves technique-sensitive accurate, and efficient simultaneous preconditioning and cementing of PLVs. (J Prosthet Dent procedures. PLVs are difficult 2019;-:---) to hold during the preoutcome is needed. Guiding devices have been used to conditioning procedures of hydrofluoric acid etching and facilitate implant placement,6,7 fenestration of maxillary silanization. A silicone cube technique was introduced as 4 sinus,8 gingivoplasty and alveolectomy,9 and orthodontic a safe holder for adjusting indirect prostheses. However, it is not applicable for PLVs given the fragile nature of brackets, placement of which have been reported to be these thin prostheses. Moreover, without a distinct predictable and reproducible.10-12 Computer-aided design of the guiding devices based on 3D imaging enmargin or seat on the PLV abutment teeth, detecting ables precise planning and implementation of the treatmisplacement of the PLV is difficult when excess bonding ment procedures while reducing operation time and resin covers the margins. A wooden spring clip technique complications.13-15 This technique report introduced a was described to facilitate the PLV cementation.5 Howdigitalized strategy for simultaneous preconditioning and ever, for this method, each spring clip needed to be recementing multiple PLVs by using a computer-aided contoured to achieve reliable adaptation and to maintain stability, and the PLVs were still placed onto abutment design and computer-aided manufactured (CAD-CAM) teeth by hand, so misplacement may occur. guiding device. The technique is described on a patient receiving 6 PLVs to improve esthetics affected by dental A method involving simultaneous placement of fluorosis. multiunit PLVs with a reliable and predictable clinical
This dental technique report was supported by the Key Medical Talents Project of Jiangsu Province (ZDRCC2016017). X.C. and N.Z. contributed equally to the work and should be regarded as joint first authors. a Attending Physician, Department of Prosthodontics, Stomatological Digital Engineering Center, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China. b Associate Chief Physician, Department of Endodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China. c Attending Physician, Department of Endodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China. d Senior Associate Technician, Department of Dental Laboratory, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China. e Resident and Master Degree Candidate, Department of Prosthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China. f Associate Professor, Department of Prosthodontics, Stomatological Digital Engineering Center, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China.
THE JOURNAL OF PROSTHETIC DENTISTRY
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Figure 1. Preoperative scan of maxillary dentition.
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Figure 2. Porcelain laminate veneers fitted on 3D printed definitive cast.
Figure 3. CAD-CAM guiding device. A, Design of guiding device with labial margin 2 mm from veneer margin. B, Perforations provided on lingual surfaces of guiding device. C, Guiding device after milling procedure. D, Definitive guiding device. CAD-CAM, computer-aided design and computer-aided manufacturing.
TECHNIQUE 1. Make an intraoral scan (TRIOS; 3Shape A/S) to obtain digital data of the teeth before treatment (Fig. 1). Prepare the teeth and scan these and the opposing arch, transform the scans to standard tessellation language (STL) file format, and input to a 3D printer THE JOURNAL OF PROSTHETIC DENTISTRY
(ProJet MJP 3600; 3D System) to print the definitive cast. 2. Design the PLVs in a dental CAD software program (3Shape Dental System; 3Shape A/S). Mill the PLVs from lithium disilicate ceramic blocks (IPS e.max CAD; Ivoclar Vivadent AG) by using a milling system (DWX-4W;
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Figure 4. Laboratory and clinical evaluation. A, PLVs seated in guiding device. B, PLVs simultaneously fitted to definitive cast facilitated by guiding device. C, PLVs fitted to abutment teeth by guiding device. D, Occlusal view of guiding device. PLVs, porcelain laminate veneers.
Roland DG Corp). Accurately fit the PLVs on the definitive cast (Fig. 2) and digitalize them by using a desktop scanner (D2000; 3Shape A/S) to obtain an STL file of the PLVs and definitive cast assembly. 3. Design the guiding device on the digital cast of the PLVs and definitive cast, with the labial cervical margin 2 mm short of the margins of the PLVs. Provide lingual perforations on all the abutment teeth. Adjust the path of insertion of the guide to eliminate unwanted undercuts and block the remaining undercuts. Set the thickness to approximately 1.5 mm to ensure the guiding device has adequate strength while providing sufficient flexibility to allow for easy insertion and removal (Fig. 3A, 3B). Extend the guiding device to the first premolars for stable retention. Mill the guiding device from a polymethyl methacrylate (PMMA) disk (Zenotec PMMA Cast; Wieland Dental) by using a milling system (Zenotec Select Ion; Wieland Dental) (Fig. 3C, 3D). 4. Insert the PLVs into the guiding device (Fig. 4A) and first evaluate the device loaded with PLVs on the definitive cast (Fig. 4B). Then, determine the ease of insertion, fit, retention, and stability of the guiding device intraorally on the abutment teeth. Also examine marginal fit and complete seating of the PLVs (Fig. 4C, 4D).
Chen et al
Figure 5. Silane applied to porcelain laminate veneers seated in guiding device.
5. Seat the PLVs into the guiding device after the etching procedure and apply the silane coupling agent (BIS-Silane Part A & B; BISCO Dental) to the intaglio surfaces (Fig. 5) according to the manufacturer’s instructions. 6. Etch (Uni-Etch w/BAC; BISCO Dental) the prepared teeth according to the manufacturer’s instructions.
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Figure 6. Cemented porcelain laminate veneers. A, Frontal view. B, Occlusal view.
7. Load an appropriate amount of resin luting cement (Choice 2 Veneer Cement; BISCO Dental) onto the intaglio surface of the PLVs seated in the guiding device. Gently place the guiding device with PLVs onto the abutment teeth, carefully evaluating the marginal fit with an explorer. Light-polymerize the resin luting cement through the transparent guide for 1 or 2 seconds, tack polymerize the excess cement beyond the gingival margins and lingual perforations, and then use a sharp scalpel to remove the excess gel-like cement in a parallel-to-margin motion. Gently remove the guiding device. Carefully pull dental floss through the interproximal contacts to remove any residual cement. Reevaluate for marginal fit and any residual cement in the marginal and interproximal regions. 8. Complete the polymerization of resin luting cement from the lingual, incisal, and labial directions. Evaluate the esthetics and adjust the occlusion of the PLVs, followed by definitive polishing (Fig. 6). DISSCUSSION The traditional freehand PLV cementation method is technique-sensitive. Errors may occur, especially in the preconditioning process and the fitting of PLVs with finger pressure, resulting in compromised restoration outcomes. The repetitive bonding operations for multiunit PLVs increase the risk for complications, with lengthened chairside time and poor patient experience. The presented technique that facilitates PLV cementation with improved accuracy was partially inspired by the indirect bracket bonding technique used in orthodontics.10-12 To effectively remove excess cement and to confirm the complete seating of PLVs, a 2-mm gap was designed from the PLV margins together with lingual perforations. Thus, excess resin cement flows through the labial gap and the lingual perforations, while the guide hold the PLVs in place, facilitating the process. The thickness of the guiding device was set to 1.5 mm, which allowed for flexibility while maintaining
THE JOURNAL OF PROSTHETIC DENTISTRY
adequate strength. The path of insertion was set to an incisal to gingival direction, with undercuts eliminated so that the guiding device could be easily inserted and removed from the prepared teeth without exerting pressure. The choice of transparent PMMA material allowed for direct light polymerization without the need to remove the guiding device and also enabled direct observation of the positioning and seating condition of PLVs. SUMMARY This report describes a CAD-CAM guiding device for the simultaneous preconditioning and cementation of multiunit PLVs. In contrast with the conventional method, this technique provides a predictable, accurate, and effective way of preconditioning and cementing PLVs. Although additional laboratory work is required for the guiding device, chairside time should be reduced with improved accuracy. Clinical studies are needed to evaluate quantitatively the efficacy and accuracy of the presented technique. REFERENCES 1. Arif R, Dennison JB, Garcia D, Yaman P. Retrospective evaluation of the clinical performance and longevity of porcelain laminate veneers 7 to 14 years after cementation. J Prosthet Dent 2019;122:31-7. 2. Dumfahrt H, Schaffer H. Porcelain laminate veneers. A retrospective evaluation after 1 to 10 years of service: part II clinical results. Int J Prosthodont 2000;13:9-18. 3. Addison O, Fleming GJP. The influence of cement lute, thermocycling and surface preparation on the strength of a porcelain laminate veneering material. Dent Mater 2004;20:286-92. 4. Afrashtehfar KI, Buser D, Belser UC. A safe holder for adjusting indirect prostheses: the silicone cube technique. J Prosthet Dent 2018;120:313-5. 5. Ra’fat IF, Aldhafeeri AF, Alogaili RS. A technique to facilitate ceramic veneer cementation. J Prosthet Dent 2018;20:194-7. 6. Fortin T, Champleboux G, Lormée J, Coudert JL. Precise dental implant placement in bone using surgical guides in conjunction with medical imaging techniques. J Oral Implantol 2000;26:300-3. 7. Becker CM, Kaiser DA. Surgical guide for dental implant placement. J Prosthet Dent 2000;83:248-51. 8. Goodacre BJ, Swamidass RS, Lozada J, Al-Ardah A, Sahl EA. 3D-printed guide for lateral approach sinus grafting: a dental technique. J Prosthet Dent 2018;119:897-901.
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9. Liu X, Yu J, Zhou J, Tan JG. A digitally guided dual technique for both gingival and bone resection during crown lengthening surgery. J Prosthet Dent 2018;119:345-9. 10. Castilla AE, Crowe JJ, Moses JR, Wang M, Ferracane JL, Covell DA Jr. Measurement and comparison of bracket transfer accuracy of five indirect bonding techniques. Angle Orthod 2014;84:607-14. 11. Nichols DA, Gardner G, Carballeyra AD. Reproducibility of bracket positioning in the indirect bonding technique. Am J Orthod Dentofacial Orthop 2013;144:770-6. 12. Brown MW, Koroluk L, Ko CC, Zhang K, Chen M, Nguyen T. Effectiveness and efficiency of a CAD/CAM orthodontic bracket system. Am J Orthod Dentofacial Orthop 2015;148:1067-74. 13. Nokar S, Moslehifard E, Bahman T, Bayanzadeh M, Nasirpouri F, Nokar A. Accuracy of implant placement using a CAD/CAM surgical guide: an in vitro study. Int J Oral Maxillofac Implants 2011;26:520-6. 14. Pettersson A, Kero T, Gillot L, Cannas B, Fäldt J, Söderberg R, et al. Accuracy of CAD/CAM-guided surgical template implant surgery on human cadavers: part I. J Prosthet Dent 2010;103:334-42.
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15. Cassetta M, Giansanti M, Di Mambro A, Calasso S, Barbato E. Minimally invasive corticotomy in orthodontics using a three-dimensional printed CAD/ CAM surgical guide. Int J Oral Maxillofac Surg 2016;45:1059-64. Corresponding author: Dr Guofeng Wu Department of Prosthodontics Stomatological Digital Engineering Center Nanjing Stomatological Hospital Medical School of Nanjing University 30 Zhongyang Road, Xuanwu District Nanjing, Jiangsu Province PR CHINA Email: [email protected] Copyright © 2019 by the Editorial Council for The Journal of Prosthetic Dentistry. https://doi.org/10.1016/j.prosdent.2019.10.011
THE JOURNAL OF PROSTHETIC DENTISTRY