1
|
Kang CM, Hsu WC, Chen MS, Wu HY, Mine Y, Peng TY. Fracture characteristics and translucency of multilayer monolithic zirconia crowns of various thicknesses. J Dent 2024; 145:105023. [PMID: 38670331 DOI: 10.1016/j.jdent.2024.105023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 04/28/2024] Open
Abstract
OBJECTIVES Multilayer monolithic zirconia (M-Zr) crowns can be engineered to achieve gradational translucency and color intensity. However, this modification may compromise the mechanical strength, raising concerns regarding the ability of M-Zr crowns to withstand occlusal stresses. The effects of M-Zr crown thickness on translucency and ability to endure occlusal forces were investigated at different tooth positions (incisors, premolars, and molars). The objective was to determine the minimal thickness of M-Zr crowns used in tooth preparation to meet aesthetic and functional demands. METHODS M-Zr samples (Vita A1) with four thicknesses (0.5, 1.0, 1.5, and 2.0 mm) were prepared and subjected to translucency testing using a digital colorimeter by 3-third and 9-square division methods. Crown-shaped M-Zr samples with three thicknesses (1.0, 1.5, and 2.0 mm) and three tooth positions (incisor, premolar, and molar) were digitally designed, and 2.0 mm metal abutments were fabricated. The samples were bonded to the abutments; their fracture characteristics were evaluated using a universal testing machine, and their fracture surfaces examined using an optical microscope. Statistical analyses included the Shapiro-Wilk test, Pearson correlation, and one-way and two-way ANOVA with a post hoc Tukey HSD test (α = 0.05). RESULTS Color analysis results revealed a significant negative correlation between thickness and translucency (r < -0.96, P < 0.01), with the highest values in the incisal region. Cross-sectional profiles confirmed the uniform thickness and morphology of the digitally designed M-Zr crowns. The results of fracture strength analysis showed position-dependent variability, a strong positive correlation with thickness (r > 0.96, P < 0.01), and fracture strengths consistently exceeding 1200 N across all tooth positions. Fracture patterns indicated that thinner crowns at the incisors and molars were more prone to cracking, whereas those at the premolars demonstrated significantly higher strength (4872.51 N, P < 0.05), only with crack or even no fracture occurring at 2.0 mm. CONCLUSIONS Thickness significantly influenced both the translucency and fracture strength of M-Zr, with the tooth position playing an additional role, albeit to a lesser extent. Although thinner crowns exhibited lower strength at each tooth position, even at a thickness of 1.0 mm, fracture strength exceeding 1200 N was maintained, surpassing the typical occlusal forces. Thus, it can be asserted that M-Zr crowns with a minimum thickness of 1.0 mm can meet both aesthetic and functional requirements.
Collapse
Affiliation(s)
- Chien-Ming Kang
- Huayi Dental Laboratory, Taipei, Taiwan; School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
| | - Wen-Chieh Hsu
- School of Dentistry, College of Oral Medicine, Chung Shan Medical University, Taichung, Taiwan; Department of Oral Hygiene, Hsin Sheng Junior College of Medical Care and Management, Taoyuan, Taiwan; Research Center of Precision Biomedical Implants, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
| | - May-Show Chen
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan; Division of Prosthodontics, Department of Dentistry, Taipei Medical University Hospital, Taipei, Taiwan
| | - Hsuan-Yu Wu
- School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yuichi Mine
- Department of Medical Systems Engineering, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan; Project Research Center for Integrating Digital Dentistry, Hiroshima University, Hiroshima, Japan
| | - Tzu-Yu Peng
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan.
| |
Collapse
|
2
|
Kuliš A, Kuliš Rader K, Kopač I. Minimally invasive prosthodontics using the concept of prosthetically guided orthodontics. J ESTHET RESTOR DENT 2024. [PMID: 38795018 DOI: 10.1111/jerd.13266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/07/2024] [Accepted: 05/08/2024] [Indexed: 05/27/2024]
Abstract
OBJECTIVE This case report aims to present how digital technology can be employed to plan the orthodontic movement of teeth into their final positions for prosthodontic rehabilitation. An interdisciplinary approach to treatment planning and the result of prosthodontic treatment involves the cooperation of an orthodontist and a prosthodontist. When planned to achieve optimal results for a minimally invasive and functional prosthodontic treatment, orthodontic pretreatment provides superior esthetic results and favorable long-term success. CLINICAL CONSIDERATIONS The orthodontic movements of the teeth were planned so that the prosthodontist could reconstruct an optimally functional and esthetic occlusion while preserving the hard dental tissues. The orthodontic pretreatment minimized the need to prepare the teeth, avoiding any mucogingival surgery to improve the gingival architecture. CONCLUSIONS In complex clinical cases, it is essential to evaluate the advantages of an orthodontic pretreatment before starting a prosthodontic treatment. This pretreatment can help preserve dental tissues, reduce or eliminate the need for surgical intervention, and achieve long-term stability and esthetic results. CLINICAL SIGNIFICANCE This case clearly shows the benefits of orthodontic pretreatment for prosthodontic outcomes. With modern digital tools, such an orthodontic pretreatment should become standard clinical practice when planning a complex clinical case.
Collapse
Affiliation(s)
| | | | - Igor Kopač
- Center of Fixed Prosthodontics and Occlusion, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
3
|
Takaesu Y, Isshi K, Toguchi T, Matsuura T. Providing a monolithic zirconia fixed partial denture with rigid and nonrigid connectors to overcome nonparallel abutment teeth. J Prosthet Dent 2024:S0022-3913(24)00238-5. [PMID: 38641479 DOI: 10.1016/j.prosdent.2024.03.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 03/02/2024] [Accepted: 03/06/2024] [Indexed: 04/21/2024]
Abstract
This clinical report describes the fabrication of a monolithic zirconia fixed partial denture using rigid and nonrigid connectors to overcome nonparallel abutment teeth. A precise key and keyway in the ceramic material was designed with digital technology, reducing material costs, improving biocompatibility, and using esthetically superior nonmetallic materials.
Collapse
Affiliation(s)
- Yu Takaesu
- Assistant Professor, Department of Oral Rehabilitation, Section of Fixed Prosthodontics, Fukuoka Dental College, Fukuoka, Japan.
| | - Kota Isshi
- Dental Technician,Fukuoka Dental College Medical & Dental General Hospital Central Dental Laboratory, Fukuoka, Japan
| | - Taisei Toguchi
- Graduate student, Department of Oral Rehabilitation, Section of Fixed Prosthodontics, Fukuoka Dental College, Fukuoka, Japan
| | - Takashi Matsuura
- Professor, Department of Oral Rehabilitation, Section of Fixed Prosthodontics, Fukuoka Dental College, Fukuoka, Japan
| |
Collapse
|
4
|
Zhang Y, Luo J, Di P, Chen B, Li J, Yu Z, Lin Y. Screw-retained ceramic-veneered/monolithic zirconia partial implant-supported fixed dental prostheses: A 5 to 10-year retrospective study on survival and complications. J Prosthodont 2024; 33:221-230. [PMID: 37302066 DOI: 10.1111/jopr.13723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 06/02/2023] [Indexed: 06/12/2023] Open
Abstract
PURPOSE To assess the clinical performance of screw-retained, ceramic-veneered, monolithic zirconia partial implant-supported fixed dental prostheses (ISFDP) over 5-10 years and to evaluate implant- and prosthesis-related factors influencing treatment failure and complications. MATERIALS AND METHODS Partially edentulous patients treated with screw-retained all-ceramic ISFDPs with 2-4 prosthetic units with a documented follow-up of ≥5 years after implant loading were included in this retrospective study. The outcomes analyzed included implant/prosthesis failure and biological/technical complications. Possible risk factors were identified using the mixed effects Cox regression analysis. RESULTS A screened sample of 171 participants with 208 prostheses (95% of the restorations were splinted crowns without a pontic) supported by 451 dental implants were enrolled in this study. The mean follow-up duration after prosthesis delivery was 82.4 ±17.2 months. By the end of the follow-up period, 431 (95.57%) of the 451 implants remained functional at the implant level. At the prosthesis level, 185 (88.94%) of the 208 partial ISFDPs remained functional. Biological complications were observed in 67 implants (14.86%), and technical complications were observed in 62 ISFDPs (29.81%). Analysis revealed only emergence profiles (over-contoured) as a significant risk factor for implant failure (P<0.001) and biological complications (P<0.001). Full-coverage ceramic-veneered zirconia prostheses had a significantly greater chance of chipping (P<0.001) compared with buccal-ceramic-veneered or monolithic zirconia prostheses. CONCLUSIONS Screw-retained ceramic-veneered, monolithic partial ISFDPs have a favorable long-term survival rate. Over-contoured emergence profile is a significant risk factor associated with implant failure and biological complications. Buccal-ceramic-veneered and monolithic zirconia partial ISFDPs lower the initial prevalence of chipping compared with a full-coverage veneered design.
Collapse
Affiliation(s)
- Yifan Zhang
- Department of Oral Implantology, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, PR China
| | - Jia Luo
- Department of Oral Implantology, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, PR China
| | - Ping Di
- Department of Oral Implantology, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, PR China
| | - Bo Chen
- Department of Oral Implantology, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, PR China
| | - Jianhui Li
- Department of Oral Implantology, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, PR China
| | - Ziyang Yu
- Department of Oral Implantology, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, PR China
| | - Ye Lin
- Department of Oral Implantology, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, PR China
| |
Collapse
|
5
|
Steiner R, Scott S, Wiesmüller V, Lepperdinger U, Steinmassl O, Schnabl D, Schwindling S. Effect of zirconia surface conditioning before glazing on the wear of opposing enamel: an in vitro study. Clin Oral Investig 2024; 28:128. [PMID: 38294555 DOI: 10.1007/s00784-024-05522-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 01/18/2024] [Indexed: 02/01/2024]
Abstract
OBJECTIVES This in vitro study aimed to evaluate the wear of natural teeth opposing 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) with different surface conditions. MATERIALS AND METHODS Sixty 3Y-TZP specimens were randomly assigned to six groups (n = 10), differing in surface condition. In three groups, the samples underwent glazing-with the glaze applied to roughened (i.e., 106-µm-grit diamond-finished), as-sintered, and polished zirconia. The three remaining groups consisted of unglazed specimens: solely polished samples and diamond-finished samples (106-µm-grit and 46-µm-grit) without further conditioning. Two-body wear was evaluated at extracted, non-carious molars (n = 60), which served as antagonists in chewing simulation (10,000 masticatory cycles, 49N load). As a control, natural teeth with intact enamel surfaces were tested against natural molars (n = 10). All samples were 3D-scanned before and after the chewing simulation (7 Series, Straumann). Volume loss was calculated (Inspect Software, GOM), and statistically analyzed (SPSS Statistics 24, IBM). RESULTS Volume loss of the natural antagonists decreased in the following order: 106-µm-grit diamond-finished zirconia (4.6 ± 2.5 mm3), glazed 106-µm-grit diamond-finished zirconia (3.8 ± 1.1 mm3), glazed as-sintered zirconia (3.5 ± 0.9 mm3), 46-µm-grit diamond-finished zirconia (1.7 ± 0.6 mm3), control (1.6 ± 0.7 mm3), glazed polished zirconia (1.4 ± 0.5 mm3), and solely polishing (0.4 ± 0.2 mm3). Even when polishing the surfaces before glazing, volume loss was not mitigated to the same extent as after polishing alone. CONCLUSIONS The zirconia surface condition beneath the glazing influences antagonist wear. Although polishing before glazing resulted in acceptable levels of antagonist wear, this approach did not yield as favorable results as polishing alone. CLINICAL RELEVANCE For operators favoring glazing, pre-polishing the zirconia surface could be advantageous to reduce wear.
Collapse
Affiliation(s)
- René Steiner
- Department of Prosthetic Dentistry, Medical University Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria.
| | - Shawn Scott
- Private Dental Practice, Oberndorferstraße 39, 6322, Kirchbichl, Austria
| | - Vera Wiesmüller
- Department of Conservative Dentistry and Periodontology, Medical University Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria
| | - Ulrike Lepperdinger
- Department of Conservative Dentistry and Periodontology, Medical University Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria
| | - Otto Steinmassl
- Private Dental Practice, Kaiser-Josef Straße 13, 6020, Innsbruck, Austria
| | - Dagmar Schnabl
- Department of Prosthetic Dentistry, Medical University Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria
| | - Sebastian Schwindling
- Department of Prosthetic Dentistry, Medical University Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria
| |
Collapse
|
6
|
Zhu H, Zhou Y, Jiang J, Wang Y, He F. Accuracy and margin quality of advanced 3D-printed monolithic zirconia crowns. J Prosthet Dent 2023:S0022-3913(23)00444-4. [PMID: 37591717 DOI: 10.1016/j.prosdent.2023.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 08/19/2023]
Abstract
STATEMENT OF PROBLEM Nanoparticle jetting (NPJ) is a novel ceramic 3D-printing technology with high printing accuracy. However, studies reporting the accuracy of zirconia crowns manufactured by NPJ and comparing them with conventional zirconia crowns are lacking. PURPOSE The purpose of this in vitro study was to evaluate and compare the trueness, crown fit, and margin quality of monolithic zirconia crowns manufactured by NPJ with those milled by a computer numerical control system. MATERIAL AND METHODS A gypsum left mandibular first molar was prepared and scanned with an intraoral scanner (TRIOS 4). Three types of monolithic crowns were manufactured through 3D printing and subtractive manufacturing (SM): NPJ (3D printing), VITA (milling), UPCERA (milling). The crowns were scanned, and the dimensional deviation (trueness) was evaluated and compared by using a software program. The triple scan method was used to measure crown fit and uniform index through precise alignment in the software program, and margin quality was also observed with an optical microscope. The data were analyzed with 1-way analysis of variance and the Tukey post hoc test (α=.05). RESULTS The NPJ group reported better trueness of all crown and axial surfaces compared with the other SM group (P<.001), but marginal trueness (P=.601), intaglio surface (P=.596), and occlusal surface (P=.641) were statistically similar compared with the Vita milled group. All 3 groups reported clinically acceptable crown fit and uniformity with statistically similar values (P>.05). The NPJ group had more crowns judged to have flawless margin quality compared with the milled groups. CONCLUSIONS All 3 manufacturing methods can fabricate zirconia crowns with a clinically acceptable crown fit. The NPJ system could be used to manufacture monolithic zirconia crowns with better margin quality and proximal surface trueness than milled crowns.
Collapse
Affiliation(s)
- Han Zhu
- Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Yi Zhou
- Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Jimin Jiang
- Department of Prosthodontics, Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Yujie Wang
- Department of Periodontics, Department of Prosthodontics, Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Fuming He
- Department of Prosthodontics and Implantology, Department of Prosthodontics, Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China.
| |
Collapse
|
7
|
Bonfante EA, Calamita M, Bergamo ETP. Indirect restorative systems-A narrative review. J ESTHET RESTOR DENT 2023; 35:84-104. [PMID: 36688803 DOI: 10.1111/jerd.13016] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/24/2023]
Abstract
OBJECTIVE The background and clinical understanding of the properties of currently available indirect restorative systems and fabrication methods is, along with manufacturer and evidence-based literature, an important starting point to guide the clinical selection of materials for tooth and/or implant supported reconstructions. Therefore, this review explores most indirect restorative systems available in the market, especially all-ceramic, along with aspects of manufacturing process, clinical survival rates, and esthetic outcomes. OVERVIEW Progressive incorporation of new technologies in the dental field and advancements in materials science have enabled the development/improvement of indirect restorative systems and treatment concepts in oral rehabilitation, resulting in reliable and predictable workflows and successful esthetic and functional outcomes. Indirect restorative systems have evolved from metal ceramics and polymers to glass ceramics, polycrystalline ceramics, and resin-matrix ceramics, aiming to improve not only biological and mechanical properties, but especially the optical properties and esthetic quality of the reconstructions, in attempt to mimic natural teeth. CONCLUSIONS Based on several clinical research, materials, and patient-related parameters, a decision tree for the selection of indirect restorative materials was suggested to guide clinicians in the rehabilitation process. CLINICAL SIGNIFICANCE The pace of materials development is faster than that of clinical research aimed to support their use. Since no single material provides an ideal solution to every case, professionals must continuously seek information from well designed, long-term clinical trials in order to incorporate or not new materials and technological advancements.
Collapse
Affiliation(s)
- Estevam A Bonfante
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil
| | - Marcelo Calamita
- Department of Restorative Dental Sciences at the University of Florida, Gainesville, Florida, USA
| | - Edmara T P Bergamo
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil
| |
Collapse
|