1
|
Chebib N, Imamura Y, El Osta N, Srinivasan M, Müller F, Maniewicz S. Fit and retention of complete denture bases: Part II - conventional impressions versus digital scans: A clinical controlled crossover study. J Prosthet Dent 2024; 131:618-625. [PMID: 36055812 DOI: 10.1016/j.prosdent.2022.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/15/2022] [Accepted: 07/15/2022] [Indexed: 11/24/2022]
Abstract
STATEMENT OF PROBLEM Although the intraoral scanning of edentulous ridges is feasible, clinical evidence that the resulting denture retention is equivalent to that achieved with conventional impressions is lacking. PURPOSE The purpose of this clinical study was to determine the retention of complete denture bases fabricated from digital intraoral scans versus conventional impressions by using border molding and posterior palatal seal compression. MATERIAL AND METHODS Twenty volunteers with an edentulous maxilla were recruited. An intraoral scan of the maxilla and a conventionally border-molded impression with a custom tray were made. The conventional impression was poured; the definitive cast was scanned. Three-dimensionally (3D) printed (PB1) and milled bases (MB1) were fabricated based on the scan of the definitive cast. Based on the intraoral scan, a 3D printed (PB2) and a milled base (MB2) were fabricated. On each base, a platform with a hook consisting of a central notch orienting the force against the post dam (PD) and 2 lateral notches orienting the forces against the left (LT) and right (RT) tuberosities was set in the center of the outer surface of the base. A traction dynamometer was inserted in the hook and oriented into the corresponding notch by applying force until dislodgement. All bases were subsequently stored in artificial saliva for 2 weeks and scanned. Retention testing was repeated by using the same procedure. To evaluate trueness and to visualize the differences on a color map, the scan of the definitive cast and the intraoral scans were matched and compared in 3 dimensions. The Wilcoxon tests were used to compare the retention of the different bases (95% confidence interval, α=.05). RESULTS Nineteen participants with a mean ±standard deviation age of 64.1 ±14.7 years completed the 4 study sessions. The retention of printed bases (PD: 16.08 ±15.28 N; LT: 14.98 ±14.72 N; RT: 11.28 ±9.57 N) and milled bases (PD:14.52 ±17.07 N; RT: 11.99 ±12.10 N; LT: 13.55 ±15.53 N) fabricated from conventional impressions presented significantly higher retentive forces than those printed (PD: 6.21 ±4.72 N; RT:5.12 ±2.78 N; LT: 4.45 ±2.77 N) and milled (PD: 6.58 ±4.92 N; RT: 4.65 ±2.63 N; LT: 5.02 ±3.58 N) from the intraoral scans (P<.05). The differences were significant in all directions of dislodgement, as well as after storage in artificial saliva for 2 weeks. Comparison of the 3D distances between the intraoral scan and the definitive cast revealed a mean deviation of 0.45 ±0.11 mm. CONCLUSIONS Conventional impressions of the edentulous maxilla, including the clinical steps of border molding and posterior palatal seal compression, provide better retention than digital intraoral scans with both milled and 3D printed denture bases.
Collapse
Affiliation(s)
- Najla Chebib
- Research and Teaching Fellow, Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland.
| | - Yoshiki Imamura
- Research and Teaching Fellow, Division of Fixed Prosthodontics, School of Dentistry, Meikai University, Saitama, Japan; Research and Teaching Fellow, Department of Geriatric Dentistry, School of Dentistry, Showa University, Tokyo, Japan
| | - Nada El Osta
- Professor, Department of Prosthodontics and Cranio-Facial Research Laboratory, Faculty of Dental Medicine, Saint Joseph University of Beirut, Beirut, Lebanon; Lecturer, Center for Research in Clinical Odontology, University of Clermont Auvergne, Clermont-Ferrand, France
| | - Murali Srinivasan
- Professor, Clinic of General-, Special care and Geriatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland; Research and Teaching Fellow, Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland
| | - Frauke Müller
- Professor, Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland; Professor, Division of Geriatrics, Department of Rehabilitation and Geriatrics, University Hospitals of Geneva, Thônex, Switzerland
| | - Sabrina Maniewicz
- Research and Teaching Fellow, Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland
| |
Collapse
|
2
|
Schiller S, Rustemeier E, Kraus D, Stark H, Müller F, Utz KH. Misfit of Complete Maxillary Dentures' Posterior Palatal Seal following Polymerisation with Four Different Autopolymerising Resins: An In Vitro Study. MATERIALS (BASEL, SWITZERLAND) 2022; 15:5285. [PMID: 35955220 PMCID: PMC9369520 DOI: 10.3390/ma15155285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 11/21/2022]
Abstract
BACKGROUND The majority of complete dentures are still conventionally manufactured using a flask-and-pack technique. However, the polymerization process may introduce a distortion of the denture body. The aim of this study was to evaluate the three-dimensional fit of the posterior palatal seal of maxillary complete dentures with the original impression, and to give recommendations for scraping. METHODS Four autopolymerising resins were used to manufacture 40 palatal plates each for high, medium and flat palates (total n = 120). The misfit was captured by taking a reline impression with a highly fluid silicone, the dimensions of which were measured with a flat-bed scanner. RESULTS The shape of the palate had a significant impact (median p = 0.0435), but not the resin type (median p = 0.2575). It was largest for the flat palate and smallest for the high palate. The largest misfit was observed in the palatal midline area (flat-palate average median: 685 µm; high and medium palates: 620 µm) decreasing towards the lateral and anterior regions. CONCLUSIONS The results suggest compensating for the palatal misfit that occurs with autopolymerising resins by scraping a postdam of an approximately 0.7 mm depth to the master cast, decreasing towards the anterior and lateral areas. In high and medium palates, the scraping could be less pronounced.
Collapse
Affiliation(s)
- Simone Schiller
- Independent Researcher, Kastanienstraße 10, 53340 Meckenheim, Germany;
| | - Elke Rustemeier
- Global Precipitation Climatology Centre, Deutscher Wetterdienst, Frankfurter Straße 135, 63067 Offenbach am Main, Germany;
| | - Dominik Kraus
- Department of Prosthodontics, Preclinical Education and Dental Material Science, University of Bonn, Welschnonnenstr. 17, 53111 Bonn, Germany; (D.K.); (H.S.)
| | - Helmut Stark
- Department of Prosthodontics, Preclinical Education and Dental Material Science, University of Bonn, Welschnonnenstr. 17, 53111 Bonn, Germany; (D.K.); (H.S.)
| | - Frauke Müller
- Division de Gérodontologie et Prothèse Adjointe, Clinique Universitaire de Médecine Dentaire (CUMD), 1 rue Michel-Servet, 1211 Geneva, Switzerland;
| | - Karl-Heinz Utz
- Department of Prosthodontics, Preclinical Education and Dental Material Science, University of Bonn, Welschnonnenstr. 17, 53111 Bonn, Germany; (D.K.); (H.S.)
- Independent Researcher, Käferweg 1, 53639 Königswinter, Germany
| |
Collapse
|
3
|
El-Shaheed NH, Lamfon HA, Salama RI, Faramawy AMG, Mostafa AZH. Tissue Surface Adaptation and Clinical Performance of CAD-CAM Milled versus Conventional Implant-Assisted Mandibular Overdenture. Int J Dent 2022; 2022:8220233. [PMID: 35756959 PMCID: PMC9225844 DOI: 10.1155/2022/8220233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/18/2022] [Accepted: 06/02/2022] [Indexed: 12/03/2022] Open
Abstract
Purpose To evaluate the surface adaptation and maximal biting force of CAD-CAM milled mandibular overdenture (CAD-CAM MOD) compared to conventional compression mold mandibular overdenture (CC MOD). Materials and Methods Ten completely edentulous subjects with persistent complaints of their complete mandibular dentures were received four dental implants in the anterior mandible. Three months after osseointegration, subjects were randomly received either conventional compression mold or CAD-CAM MOD in a crossover design. To assess tissue surface adaptation, the fitting surfaces of each denture base were scanned and placed on the reference master cast. Three and six months after each overdenture was inserted, clinical performance in the form of maximum biting force was evaluated. Results The results of this study indicated that the tissue surface adaptation of the CAD-CAM MOD bases was significantly better than the conventional (compression mold technique) processed bases where (P=0.0001). Regarding clinical performance (maximum biting force), the CAD-CAM MOD exhibited better clinical performance (P=0.0001). Conclusions In denture processing methods, the CAD-CAM overdenture delivered more precise adaption and clinical performance than the compression mold technique.
Collapse
Affiliation(s)
- Noha H. El-Shaheed
- Prosthodontic Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt
| | - Hanadi A. Lamfon
- Removable Prosthodontics, Faculty of Dentistry, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Rabab. I. Salama
- Pediatric Dentistry and Dental Public Health Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt
| | - Amira Mohammed Gomaa Faramawy
- Prosthodontic Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt
- Removable Prosthodontics, Faculty of Dentistry, Umm Al-Qura University, Makkah, Saudi Arabia
| | | |
Collapse
|
4
|
Shin SH, Doh RM, Lim JH, Kwon JS, Shim JS, Kim JE. Evaluation of Dimensional Changes According to Aging Period and Postcuring Time of 3D-Printed Denture Base Prostheses: An In Vitro Study. MATERIALS 2021; 14:ma14206185. [PMID: 34683773 PMCID: PMC8539717 DOI: 10.3390/ma14206185] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/14/2021] [Accepted: 10/16/2021] [Indexed: 11/16/2022]
Abstract
During the three-dimensional (3D) printing process of a dental prosthesis, using photopolymer resin, partially polymerized resin is further cured through the postcuring process that proceeds after the printing, which improves the stability of the printed product. The mechanical properties of the end product are known to be poor if the postcuring time is insufficient. Therefore, this study evaluated the effect of the postcuring time of the 3D-printed denture base on its dimensional stability, according to the aging period. The 3D prints were processed after designing maxillary and mandibular denture bases, and after the following postcuring times were applied: no postcuring, and 5, 15, 30, and 60 min. The dimensional stability change of the denture base was evaluated and analyzed for 28 days after the postcuring process. The trueness analysis indicated that the mandibular denture base had lower output accuracy than the maxillary denture base, and the dimensional stability change increased as postcuring progressed. In the no postcuring group for the mandible, the error value was 201.1 ± 5.5 µm (mean ± standard deviation) after 28 days, whereas it was 125.7 ± 13.0 µm in the 60 min postcuring group. For both the maxilla and the mandible, shorter postcuring times induced larger dimensional stability changes during the aging process. These findings indicate that in order to manufacture a denture base with dimensional stability, a sufficient postcuring process is required during the processing stage.
Collapse
Affiliation(s)
- Seung-Ho Shin
- BK21 FOUR Project, Oral Research Science Center, Department of Prosthodontics, Yonsei University College of Dentistry, Yonsei-ro 50-1, Seoul 03722, Korea; (S.-H.S.); (J.-H.L.)
| | - Re-Mee Doh
- Department of Advanced General Dentistry, College of Dentistry, Dankook University, Cheonan 31116, Korea;
| | - Jung-Hwa Lim
- BK21 FOUR Project, Oral Research Science Center, Department of Prosthodontics, Yonsei University College of Dentistry, Yonsei-ro 50-1, Seoul 03722, Korea; (S.-H.S.); (J.-H.L.)
| | - Jae-Sung Kwon
- Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 03722, Korea;
| | - June-Sung Shim
- Department of Prosthodontics, Yonsei University College of Dentistry, Yonsei-ro 50-1, Seoul 03722, Korea;
| | - Jong-Eun Kim
- Department of Prosthodontics, Yonsei University College of Dentistry, Yonsei-ro 50-1, Seoul 03722, Korea;
- Correspondence: ; Tel.: +82-2-2228-3166
| |
Collapse
|