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Le Texier L, Nicolas E, Batisse C. Evaluation and comparison of the accuracy of three intraoral scanners for replicating a complete denture. J Prosthet Dent 2024; 131:706.e1-706.e8. [PMID: 38310062 DOI: 10.1016/j.prosdent.2024.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 02/05/2024]
Abstract
STATEMENT OF PROBLEM Technological advances in digital acquisition tools have increased the scope of intraoral scanners (IOSs), including scanning a removable complete denture (RCD) to replicate it. However, studies assessing the accuracy of IOSs for replicating a maxillary or mandibular RCD are lacking. PURPOSE The purpose of this in vitro study was to evaluate the accuracy (trueness and precision) of 3 IOSs while replicating a maxillary and mandibular RCD. MATERIAL AND METHODS One maxillary and 1 mandibular RCD were scanned with a desktop scanner (D2000) to obtain the reference model. Two operators scanned each RCD 5 times with 3 different IOSs (TRIOS 4, Primescan, and IS3800), following a predefined acquisition protocol. The 60 study models obtained were compared with the reference model using the Geomagic software program. For each comparison, the mean and standard deviation of discrepancy were calculated. Distances were measured on both the reference and the study model, and differences were calculated to assess whether sagittal or transverse deformations were present. The tolerance percentage of the volume of the digital model compared with the volume of the reference model was determined (difference tolerance was set at 0.1 mm). A univariate analysis of variance followed by a post hoc analysis using the Student-Newman-Keuls (α=.05) test was performed to determine the truest and the most precise IOS. RESULTS The TRIOS 4 and Primescan IOSs had comparable trueness, with mean dimensional variations of 47 ±27 µm and 57 ±8 µm respectively compared with the reference model. The IS3800 had a lower trueness (98 ±35 µm). Primescan was significantly more precise with a mean standard deviation of 64 ±15 µm (P<.05). The TRIOS 4 (141 ±48 µm) and IS3800 (129 ±24 µm) had comparable precision. Primescan showed the least sagittal and transverse deformation. CONCLUSIONS This study determined that an RCD can be replicated using an IOS, although all IOSs did not have equal accuracy. An in vivo study needs to assess whether this procedure is clinically acceptable.
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Affiliation(s)
- Louise Le Texier
- Resident, Department of Odontology, Faculty of Odontology, University Clermont Auvergne, Clermont Ferrand, France
| | - Emmanuel Nicolas
- Professor, Department of Odontology, Faculty of Odontology, University Clermont Auvergne, Clermont Ferrand, France
| | - Cindy Batisse
- Lecturer, Prosthetic Department, Faculty of Odontology, University Clermont Auvergne, Clermont Ferrand, France.
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Negm EE, Patel M, Ryan P. Impact of the superimposition reference area on intraoral scanning accuracy in a partially dentate maxilla. J Prosthet Dent 2024:S0022-3913(24)00211-7. [PMID: 38556406 DOI: 10.1016/j.prosdent.2024.03.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/14/2024] [Accepted: 03/14/2024] [Indexed: 04/02/2024]
Abstract
STATEMENT OF PROBLEM The alignment of 3-dimensional (3D) files involves selecting a reference area before performing a local best fit alignment during the digital scan superimposition and is essential for comparing digital scans. Scan alignment relies on both reference area location and the alignment algorithm. However, a consensus on the impact of different reference areas on intraoral scanning accuracy is lacking. PURPOSE The purpose of this in vitro study was to assess the impact of 3 superimposition reference areas on the accuracy of 3 intraoral scanners for a partially dentate maxilla. MATERIAL AND METHODS A Kennedy class II resin cast was scanned using 3 intraoral scanners (Primescan, TRIOS 3, and Emerald) outputting 30 digital scans (10 per scanner). Test scans from intraoral scanners were subsequently compared with a reference digital standard tessellation language file generated by a laboratory scanner with validated accuracy. The files were superimposed using best fit alignment for each intraoral scanner using 3 different superimposition reference areas (whole region of interest, palate, and all teeth). Accuracy was assessed by using a 3D analysis program (Geomagic Control X; 3D systems) for each scanner at 4 preselected areas. Test and reference scan differences were depicted on color maps and quantified via root mean square deviations. Differences were analyzed using regression analysis with the post hoc student t test and Bonferroni correction (α=.05). RESULTS The TRIOS 3 and Emerald produced positive deviations in the palatal color maps, whereas Primescan produced more uniform color maps, regardless of the superimposition strategy used. Primescan exhibited the best accuracy (trueness and precision) in both palatal and bounded edentulous areas, regardless of the superimposition reference area. The TRIOS 3 recorded the highest distal extension trueness (ranging from 42.9±7.7 µm to 65 ±19.5 µm), and Primescan achieved the highest precision (ranging from 28.5 ±9.8 µm to 48.9 ±16.9 µm), regardless of the superimposition area. Emerald demonstrated the highest teeth trueness (ranging from 31.6 ±6.8 µm to 69.6 ±11.5 µm), while Primescan produced the highest precision (ranging from 17.9 ±6.1 µm to 30.7 ±9.2 µm), regardless of the reference area used. CONCLUSIONS The chosen reference area for best fit alignment significantly influenced digital scan accuracy (P<.001). Primescan displayed the highest palatal and bounded edentulous area accuracy, with TRIOS 3 recording the highest distal extension trueness. Emerald recorded the highest teeth trueness and Primescan recorded the highest distal extension and tooth precision. All conclusions were independent of the superimposition strategy used.
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Affiliation(s)
- Enas Elhamy Negm
- PhD student, Centre for Oral Bioengineering, Institute of Dentistry, Queen Mary University of London, London, England, United Kingdom; Assistant Lecturer, Department of Prosthodontics, Faculty of Dentistry, Tanta University, Tanta, Egypt.
| | - Mangala Patel
- Professor, Dental Biomaterials, Centre for Oral Bioengineering, Institute of Dentistry, Queen Mary University of London, London, England, UK
| | - Paul Ryan
- Clinical Senior Lecturer, Restorative Dentistry and Periodontology, Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Queen Mary University of London, London, England, UK
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Salem MM, Elmahy WA, Nasr DM. Effect of different intraoral scanning strategies on the marginal and internal fit of CAD-CAM inlay restorations: An in vitro study. J Prosthet Dent 2024; 131:518.e1-518.e9. [PMID: 38040555 DOI: 10.1016/j.prosdent.2023.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 12/03/2023]
Abstract
STATEMENT OF PROBLEM Whether the scanning strategy of intraoral scanners (IOSs) affects the accuracy of the digital recording for an indirect ceramic inlay restoration is unclear. Furthermore, which strategy would be optimal and most effective is uncertain. PURPOSE The purpose of this in vitro study was to evaluate the impact of 3 different scanning strategies using the Carestream CS 3700 IOS on the marginal and internal fit of a mesio-occluso-distal (MOD) ceramic inlay restoration. MATERIAL AND METHODS A typodont master model (ANA-4 VCER; Frasaco) was used with a standardized preprepared MOD inlay maxillary first molar typodont tooth (ANA-4 ZP16 CER99-008; Frasaco) (N=30). These inlay preparations were scanned with the CS 3700 IOS using 3 different scanning strategies: linear, wave, and S-figure scanning strategies. Each scan strategy group was scanned 10 times for all groups to obtain 30 standard tessellation language (STL) files. Thirty restorations were milled from lithium disilicate CAD blocks (IPS e.max; Ivoclar AG) and cemented into their typodont-prepared inlay cavities. A single examiner used a stereomicroscope to measure the marginal and internal gaps at the predetermined points. A 1-way ANOVA was used for the statistical analysis, followed by the Tukey post hoc test with Bonferroni adjustment. All tests were 2-tailed (α=.05). RESULTS All scanning strategy groups demonstrated statistically significant differences for the marginal and internal fit of the inlay restorations (P<.001). Overall, the linear scanning strategy showed the lowest mean marginal and internal gap values (29.2 ±3.6 µm and 39.0 ±6.4 µm), followed by the wave scanning strategy, which had comparable mean marginal and internal gap values: 49.1 ±3.6 µm and 48.2 ±6.0 µm, respectively. The S-figure scan strategy had the highest mean marginal and internal gap values: 50.2 ±12.6 µm and 71.3 ±7.7 µm, respectively. CONCLUSIONS Inlay restorations scanned by the linear scan strategy had the best marginal and internal fit when scanned with the CS 3700 IOS.
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Affiliation(s)
- Mohamed M Salem
- Postgraduate student, Division of Operative Dentistry, Department of Conservative Dentistry, Faculty of Dentistry, Alexandria University, Alexandria, Egypt.
| | - Waleed A Elmahy
- Professor, Division of Operative Dentistry, Department of Conservative Dentistry, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Dina M Nasr
- Lecturer, Division of Operative Dentistry, Department of Conservative Dentistry, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
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Wu HK, Chen G, Wang J, Zhang Z, Huang X, Lin X, Deng F, Li Y. Effect of prefabricated auxiliary devices and scanning patterns on the accuracy of complete-arch implant digital impressions. J Dent 2024; 140:104788. [PMID: 37992957 DOI: 10.1016/j.jdent.2023.104788] [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: 08/18/2023] [Revised: 11/15/2023] [Accepted: 11/19/2023] [Indexed: 11/24/2023] Open
Abstract
OBJECTIVES This study aimed to evaluate the impact of prefabricated auxiliary devices (PAD) and scanning patterns on the accuracy of complete-arch implant digital impressions. METHODS An edentulous maxillary model was inserted with four parallel implant analogs and four PAD. The model was scanned with D2000 dental laboratory scanner as the reference scans. Test scans were obtained by 8 different scanning patterns (SP), which including SPA, SPB, SPC, SPD, SPE, SPF, SPG and SPH, with (test group) or without (control group) using the PAD by an intraoral scanner (Aoralscan 3, 3DShining). SPA was the scanning pattern recommended by the manufacturer. Each scanning time was recorded. The related files were imported into inspection software for assessment. Aligned Ranks Transformation ANOVA, Kruskal-Wallis and Mann-Whitney tests were used to evaluate the values. The level of significance was set at α = 0.05. RESULTS The scanning patterns significantly influenced the linear accuracy in the test group and the scanning time for both groups. Lower linear trueness in the test group was found in SPF (p<0.05) and SPG (p<0.05). Longer scanning time was found in SPB and SPG for both groups. The test group demonstrated linear accuracy enhancement in all the scanning patterns; angular trueness enhancement was seen in SPA (p<0.05), SPC (p<0.01) and SPH (p<0.01). Significant longer scanning time was found in SPB (p<0.05), SPF (p<0.05), SPG (p<0.05) and SPH (p<0.05) when using PAD. CONCLUSION The scanning patterns impact the accuracy differently depending on the PAD's existence. The scanning time can be significantly influenced by the scanning patterns and the PAD. CLINICAL SIGNIFICANCE In daily clinical practice, selecting a suitable scanning pattern is significant in achieving accurate digital impressions. The PAD demonstrated effective linear accuracy enhancement in all the scanning patterns tested.
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Affiliation(s)
- Hio Kuan Wu
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, PR China
| | - Guanhui Chen
- Department of Stomatology, the Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, Guangdong 518107, PR China
| | - Jing Wang
- YangHe Dental Clinic, Guangzhou 510055, PR China
| | - Zhengchuan Zhang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, PR China
| | - Xiaoqiong Huang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, PR China
| | - Xiaoxuan Lin
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, PR China
| | - Feilong Deng
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, PR China
| | - Yiming Li
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, PR China.
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Zarauz C, Pradíes GJ, Chebib N, Dönmez MB, Karasan D, Sailer I. Influence of age, training, intraoral scanner, and software version on the scan accuracy of inexperienced operators. J Prosthodont 2023; 32:135-141. [PMID: 37837217 DOI: 10.1111/jopr.13785] [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: 05/23/2023] [Accepted: 10/05/2023] [Indexed: 10/15/2023] Open
Abstract
PURPOSE To evaluate the effect of operator age on the scan accuracy (trueness and precision) of inexperienced operators when compared with experienced operators, and how training, intraoral scanner (IOS), and software version affect scan accuracy. MATERIAL AND METHODS Thirty-four operators were sorted into groups: G1 (operators <25 years old, no experience), G2 (operators >40 years old, no experience), and G3 (experienced IOS operators). They conducted partial-arch scans before and after a 4-session training with two IOSs (Trios 3 and True Definition) and two software versions. These scans were compared with the reference scans obtained from conventional impressions and a laboratory scanner (IScan D103i) to evaluate trueness (mean root mean square values) and precision (standard deviation of root mean square values) with a software program (Geomagic Control X). Kruskal-Wallis and post-hoc Dunn's tests were used to evaluate the effect of age on the scan accuracy of inexperienced groups when compared with experienced operators, while the effect of training, IOS, and software version on scan accuracy was evaluated with Wilcoxon or Mann-Whitney U tests (α = 0.05). RESULTS Before training, G1 and G2 scans had similar accuracy (p ≥ 0.065). After training, G1 scans had higher accuracy when IOS data was pooled and had higher precision with TD (p ≤ 0.004). Training increased the scan accuracy (p < 0.001), while newer software increased the trueness of inexperienced operator scans (p = 0.015). CONCLUSIONS Age affected the scan accuracy of inexperienced operators after training, indicating that extended training may be required for older operators. Training increased the scan accuracy, and newer software increased the trueness of inexperienced operator scans.
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Affiliation(s)
- Cristina Zarauz
- Division of Fixed Prosthodontics and Biomaterials, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland
| | - Guillermo Jesus Pradíes
- Department of Conservative and Buccofacial Prosthesis, Facultad de Odontología, Universidad Complutense de Madrid, Madrid, Spain
| | - Najla Chebib
- Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland
| | - Mustafa Borga Dönmez
- Department of Prosthodontics, Faculty of Dentistry, Istinye University, İstanbul, Turkey
- Department of Reconstructive Dentistry and Gerodontology, University of Bern, Bern, Switzerland
| | - Duygu Karasan
- Division of Fixed Prosthodontics and Biomaterials, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland
| | - Irena Sailer
- Division of Fixed Prosthodontics and Biomaterials, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland
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Akl MA, Daifallah K, Pérez-Barquero JA, Barmak AB, Wee AG, Revilla-León M. Influence of interdental spaces and the palate on the accuracy of maxillary scans acquired using different intraoral scanners. J Prosthodont 2023; 32:125-134. [PMID: 37591814 DOI: 10.1111/jopr.13748] [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: 05/15/2023] [Revised: 06/26/2023] [Accepted: 07/06/2023] [Indexed: 08/19/2023] Open
Abstract
PURPOSE To assess the influence of interdental spaces and scanning the palate on the accuracy of maxillary scans acquired using three intraoral scanners (IOSs). MATERIALS AND METHODS A virtual completely dentate maxillary cast without interdental spaces was obtained and modified to create 1, 2, and 3 mm of interdental spacing between the anterior teeth. These three files (reference standard tessellation language files) were used to print three reference casts. The reference casts were scanned using three IOSs: TRIOS4, iTero Element 5D, and Aoralscan2. Three groups were created based on the interdental spaces: 0, 1, 2, and 3 mm (n = 10). The groups were subdivided into two subgroups: no palate (NP subgroup) and palate (P subgroup). The reference STL files were used to measure the discrepancy with the experimental scans by calculating the root mean square (RMS) error. Three-way analysis of variance (ANOVA) and post hoc Tukey pairwise comparison tests were used to analyze trueness. The Levene test was used to analyze precision (α = 0.05). RESULTS Trueness ranged from 91 to 139 μm and precision ranged from 5 to 23 μm among the subgroups tested. A significant correlation was found between IOS*group (p<0.001) and IOS*subgroup ( p<0.001). Tukey test showed significant trueness differences among the interdental spaces tested (p<0.001). The 1- and 2-mm groups obtained better trueness than the 0- and 3-mm groups (p<0.001). An 11 μm mean trueness discrepancy was measured among the different interdental space groups tested. The P subgroups demonstrated significantly higher trueness when compared to the NP subgroups (p<0.001). The discrepancy between the maxillary scans with and without the palate was 4 μm. Significant precision discrepancies were found (p = 0.008), with the iTero group showing the lowest precision. CONCLUSION Interdental spaces and incorporation of the palate on maxillary intraoral scans influenced trueness and precision of the three IOSs tested. However, the scanning discrepancy measured may be of no clinical relevance.
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Affiliation(s)
- Mohammed A Akl
- Woody L. Hunt School of Dental Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, Texas, United States
| | - Khaled Daifallah
- Division of Prosthodontics, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
| | | | - Abdul B Barmak
- Eastman Institute of Oral Health, University of Rochester Medical Center, Rochester, New York, USA
| | - Alvin G Wee
- Division of Prosthodontics, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Marta Revilla-León
- Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Washington, USA
- Kois Center, Seattle, Washington, USA
- Department of Prosthodontics, School of Dental Medicine, Tufts University, Boston, Massachusetts, USA
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Pan Y, Dai X, Wan F, Song C, Tsoi JK, Pow EH. A novel post-processing strategy to improve the accuracy of complete-arch intraoral scanning for implants: an in vitro study. J Dent 2023; 139:104761. [PMID: 37879557 DOI: 10.1016/j.jdent.2023.104761] [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: 06/01/2023] [Revised: 10/18/2023] [Accepted: 10/22/2023] [Indexed: 10/27/2023] Open
Abstract
OBJECTIVES To develop a new post-processing strategy that utilizes an auxiliary device to adjust intraoral scans and improve the accuracy of 3D models of complete-arch dental implants. MATERIALS AND METHODS An edentulous resin model with 6 dental implants was prepared. An auxiliary device, consisting of an opaque base and artificial landmarks, was fabricated and mounted onto the resin model. Twenty intraoral scans (raw scans) were taken using this setup. A new post-processing strategy was proposed to adjust the raw scans using reverse engineering software (verified group). Additionally, ten conventional gypsum casts were duplicated and digitized using a laboratory scanner. The linear and angular trueness and precision of the models were evaluated and compared. The effect of the proposed strategy on the accuracy of complete-arch intraoral scans was analyzed using one-way ANOVA. RESULTS The linear trueness (29.7 µm) and precision (24.8 µm) of the verified group were significantly better than the raw scans (46.6 µm, 44.7 µm) and conventional casts (51.3 µm, 36.5 µm), particularly in cross-arch sites. However, the angular trueness (0.114°) and precision (0.085°) of the conventional casts were significantly better than both the verified models (0.298°, 0.168°) and the raw scans (0.288°, 0.202°). CONCLUSIONS The novel post-processing strategy is effective in enhancing the linear accuracy of complete-arch implant IO scans, especially in cross-arch sites. However, further improvement is needed to eliminate the angular deviations. CLINICAL SIGNIFICANCE Errors generated from intraoral scanning in complete edentulous arches exceed the clinical threshold. The elimination of stitching errors in the raw scans particularly in the cross-arch sites, through the proposed post-processing strategy would enhance the accuracy of complete-arch implant prostheses.
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Affiliation(s)
- Yu Pan
- Department of Dentistry, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, China
| | - Xuanyi Dai
- Department of Dentistry, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, China
| | - Fang Wan
- School of Design, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Chaoyang Song
- Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - James Kh Tsoi
- Faculty of Dentistry, The University of Hong Kong, 3/F, Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong special administrative region of China
| | - Edmond Hn Pow
- Faculty of Dentistry, The University of Hong Kong, 3/F, Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong special administrative region of China.
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Gao Y, Hattori M, Sumita YI, Wakabayashi N. Creating and analyzing digital scans of a mandibulectomy cast with simulated trismus. J Prosthet Dent 2023:S0022-3913(23)00652-2. [PMID: 37919132 DOI: 10.1016/j.prosdent.2023.09.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 09/27/2023] [Accepted: 09/27/2023] [Indexed: 11/04/2023]
Abstract
STATEMENT OF PROBLEM Trismus associated with maxillofacial defects resulting from tumor resection or radiotherapy can make dental treatment uncomfortable for patients. Using an intraoral scanner instead of making a conventional impression could help to make prosthetic rehabilitation more comfortable. However, limited information is available regarding the feasibility and accuracy of intraoral scanners for scanning mandibular defects. PURPOSE The purpose of this in vitro study was to evaluate the feasibility and accuracy of using an intraoral scanner to digitize a cast of a mandibular defect under various simulated trismus conditions. MATERIAL AND METHODS An intraoral scanner was used to scan the mandibular cast under different simulated degrees of trismus (mouth opening 10, 20, and 30 mm) and nontrismus (mouth opening 40 mm). The surface areas captured were compared. The datasets were loaded into a 3-dimensional (3D) evaluation software program and then superimposed for precision analysis and on reference data for trueness analysis. One-way analysis of variance was used to compare surface area captured, precision, and trueness of the measurement under the different mouth opening conditions (α=.05). RESULTS The surface area for which 3D data were obtained by the intraoral scanner ranged from 3199.1 to 6161.6 mm2. The area differed significantly under all mouth opening conditions (P=.001), with a smaller scanned surface area captured in severe trismus (10 mm). Precision ranged from 0.032 to 0.056 mm, and trueness from 0.037 to 0.076 mm. No significant differences were seen in precision (P=.312), but significant differences were seen in trueness (P=.016) under all trismus conditions. CONCLUSIONS Using an intraoral scanner appears feasible for digitizing mandibular defect casts with simulated mild and moderate trismus. The accuracy of the obtained data was clinically acceptable.
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Affiliation(s)
- Yuan Gao
- Doctor and Researcher, Department of Comprehensive Treatment Clinic 2, Dalian Stomatological Hospital, Dalian, PR China
| | - Mariko Hattori
- Assistant Professor, Department of Advanced Prosthodontics, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
| | - Yuka I Sumita
- Professor, Division of General Dentistry 4, The Nippon Dental University Hospital, Tokyo, Japan
| | - Noriyuki Wakabayashi
- Professor and Chair, Department of Advanced Prosthodontics, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
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Alkadi L. A Comprehensive Review of Factors That Influence the Accuracy of Intraoral Scanners. Diagnostics (Basel) 2023; 13:3291. [PMID: 37958187 PMCID: PMC10650453 DOI: 10.3390/diagnostics13213291] [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: 09/28/2023] [Revised: 10/19/2023] [Accepted: 10/22/2023] [Indexed: 11/15/2023] Open
Abstract
Intraoral scanners (IOSs) have become increasingly popular in the field of dentistry for capturing accurate digital impressions of patients' teeth and oral structures. This study investigates the various factors influencing their accuracy. An extensive search of scholarly literature was carried out via PubMed, utilizing appropriate keywords. Factors evaluated in the included studies were categorized into three primary divisions: those related to the operator, the patient, and the IOS itself. The analysis demonstrated that the accuracy of intraoral scanning is influenced by various factors such as scanner selection, operator skill, calibration, patient's oral anatomy, ambient conditions, and scanning aids. Maintaining updated software and understanding factors beyond scanner resolution are crucial for optimal accuracy. Conversely, smaller IOS tips, fast scanning speeds, and specific scanning patterns compromise the accuracy and precision. By understanding these factors, dental professionals can make more informed decisions and enhance the accuracy of IOSs, leading to improved final dental restorations.
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Affiliation(s)
- Lubna Alkadi
- Restorative and Prosthetic Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh 11426, Saudi Arabia;
- King Abdullah International Medical Research Center, National Guard Health Affairs, Riyadh 11481, Saudi Arabia
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10
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Azevedo L, Marques T, Karasan D, Fehmer V, Sailer I, Correia A, Gómez-Polo M. Effect of splinting scan bodies on the trueness of complete-arch digital implant scans with 5 different intraoral scanners. J Prosthet Dent 2023:S0022-3913(23)00420-1. [PMID: 37537105 DOI: 10.1016/j.prosdent.2023.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 08/05/2023]
Abstract
STATEMENT OF PROBLEM The absence of fixed reference points can affect the trueness of complete-arch intraoral digital implant scans. The effect of splinting intraoral scan bodies (ISBs) or the inclusion of artificial landmarks (AL) on the trueness of complete-arch digital implant scans is still unclear. PURPOSE The purpose of this study was to analyze the effect of splinting ISBs or the inclusion of AL on the trueness of complete-arch digital implant scans with 5 intraoral scanners (IOSs). MATERIAL AND METHODS Six tissue-level dental implants (Straumann Tissue Level) were placed in an edentulous patient, and the correspondent definitive cast was digitized with a desktop scanner (IScan4D LS3i) to obtain the reference digital cast. Digital scans (n=10) were performed with 5 IOSs: TRIOS 4, Virtuo Vivo, Medit i700, iTero Element 5D, and Cerec Primescan. Three different scanning techniques were evaluated: conventional (cIOSs), splinted (sIOSs), and AL (AL-IOSs). The scan data obtained were imported into a metrology software program and superimposed to the reference digital cast by using a best-fit algorithm. The overall deviations of the positions of the ISBs were evaluated by using the root-mean-square (RMS) error (α=.05). RESULTS The mean ±standard deviation trueness values for the cIOSs, sIOSs, and AL-IOSs groups were 48 ±8 µm, 53 ±7 µm, and 49 ±11 µm, respectively, with no statistically significant differences (P=.06). Significant differences were found for the IOSs used with each technique (P<.001). Primescan (27 ±4 µm cIOSs; 28 ±3 µm sIOSs; 31 ±3 µm AL-IOSs) showed significantly higher trueness than iTero 5D (47 ±5 µm cIOSs; 47 ±4 µm sIOSs; 50 ±6 µm AL-IOSs) (P=.002) and TRIOS 4 (93 ±18 µm cIOSs; 76 ±18 µm sIOSs; 107 ±13 µm AL-IOSs) (P=.001) for all techniques. In addition, no significant differences were found between the techniques by using iTero 5D or Primescan (P=.348 and P=.059, respectively). CONCLUSIONS The cIOSs, sIOSs, and AL-IOSs techniques showed similar trueness. The IOS used influenced the trueness of complete-arch digital implant scans.
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Affiliation(s)
- Luís Azevedo
- PhD candidate, Department of Conservative Dentistry and Orofacial Prostheses, Faculty of Dentistry, Complutense University of Madrid, Madrid, Spain; Researcher, Center for Interdisciplinary Research in Health, Universidade Católica Portuguesa (UCP), Viseu, Portugal; and Research Assistant, Division of Fixed Prosthodontics and Biomaterials, University Clinics for Dental Medicine, University of Geneva, Geneva, Switzerland.
| | - Tiago Marques
- Lecturer, Faculty of Dental Medicine, Universidade Católica Portuguesa (UCP), Viseu, Portugal; and Researcher, Center for Interdisciplinary Research in Health, The Catholic University of Portugal (UCP), Viseu, Portugal
| | - Duygu Karasan
- Assistant, Division of Fixed Prosthodontics and Biomaterials, University Clinics for Dental Medicine, University of Geneva, Geneva, Switzerland
| | - Vincent Fehmer
- Master Dental Technician, Division of Fixed Prosthodontics and Biomaterials, University Clinics for Dental Medicine, University of Geneva, Geneva, Switzerland
| | - Irena Sailer
- Head, Division of Fixed Prosthodontics and Biomaterials, University Clinics for Dental Medicine, University of Geneva, Geneva, Switzerland
| | - André Correia
- Assistant Professor, Faculty of Dental Medicine, Universidade Católica Portuguesa (UCP), Viseu, Portugal; and Researcher, Center for Interdisciplinary Research in Health, The Catholic University of Portugal (UCP), Viseu, Portugal
| | - Miguel Gómez-Polo
- Associate Professor, Faculty of Dentistry, Department of Conservative Dentistry and Orofacial Prostheses, Complutense University of Madrid, Madrid, Spain
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Gracis S, Appiani A, Noè G. Digital workflow in implant prosthodontics: The critical aspects for reliable accuracy. J ESTHET RESTOR DENT 2023; 35:250-261. [PMID: 36606714 DOI: 10.1111/jerd.13004] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 01/07/2023]
Abstract
INTRODUCTION This paper is a comprehensive treaty about the variables that influence the transfer of the position of an implant to the laboratory when using a digital workflow. OBJECTIVE The aim is to provide operators and manufacturers with a guide on how to improve certain aspects of the digital workflow specific to the fabrication of implant-supported restorations. OVERVIEW It addresses intraoral scanning issues and CAD software issues. In the former, the variables that play a part in the quality of the scan file are investigated: the implant scan body, the IOS and the operator. For the latter, instead, the focus is on those aspects that still today may create inaccuracies in the workflow and in the final product being fabricated: the identification of the specific implant placed in the patient and the generation of a virtual model with the representation of that implant platform correctly positioned in the three dimensions of space. Suggestions and recommendations are given to improve the control on the quality of the digital workflow's output. CONCLUSION In a digital workflow for the fabrication of an implant-supported restoration, the selection and use of the implant scan body, the use of an effective scan strategy and the appropriateness of the best fit function in the CAD software, that is, the procedure of superimposing the library of geometric shapes of the ISB linked to the implant with the shape acquired intraorally, are variables that can influence the positional precision of the FDP. CLINICAL SIGNIFICANCE Fully understanding the importance of the information enclosed in the ISBs themselves can be crucial in the digital workflow. A proper ISB's selection, a correct scan of the ISB's shape and an accurate CAD superimposition of the ISB's library can lead the clinician to reduce the variables that affect the final result in daily practice.
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Revilla-León M, Kois DE, Kois JC. A guide for maximizing the accuracy of intraoral digital scans. Part 1: Operator factors. J ESTHET RESTOR DENT 2023; 35:230-240. [PMID: 36479807 DOI: 10.1111/jerd.12985] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/30/2022] [Accepted: 10/31/2022] [Indexed: 12/12/2022]
Abstract
OBJECTIVES To describe the factors related to the operator skills and decisions that influence the scanning accuracy of intraoral scanners (IOSs). A new classification for these factors is proposed to facilitate dental professionals' decision making when using IOSs and maximize the accuracy and reliability of intraoral digital scans. OVERVIEW Each IOS system is limited by the hardware and software characteristics of the selected device. The operator decisions that can influence the accuracy of IOSs include the scanning technology and system selection, scanning head size, calibration, scanning distance, exposure of the IOS to ambient temperature changes, ambient humidity, ambient lighting conditions, operator experience, scanning pattern, extension of the scan, cutting off, rescanning, and overlapping procedures. CONCLUSIONS The knowledge and understanding of the operator factors that impact scanning accuracy of IOSs is a fundamental element for maximizing the accuracy of IOSs and for successfully integrating IOSs in daily practices. CLINICAL SIGNIFICANCE Operator skills and clinical decisions significantly impact intraoral scanning accuracy. Dental professionals must know and understand these influencing operator factors for maximizing the accuracy of IOSs.
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Affiliation(s)
- Marta Revilla-León
- Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Washington, USA.,Kois Center, Seattle, Washington, USA.,Department of Prosthodontics, Tufts University, Boston, Massachusetts, USA
| | - Dean E Kois
- Kois Center, Seattle, Washington, USA.,Private Practice, Seattle, Washington, USA
| | - John C Kois
- Kois Center, Seattle, Washington, USA.,Private Practice, Seattle, Washington, USA.,Department of Restorative Dentistry, University of Washington, Seattle, Washington, USA
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Implementation of a Full Digital Workflow by 3D Printing Intraoral Splints Used in Dental Education: An Exploratory Observational Study with Respect to Students' Experiences. Dent J (Basel) 2022; 11:dj11010005. [PMID: 36661542 PMCID: PMC9858622 DOI: 10.3390/dj11010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/11/2022] [Accepted: 12/16/2022] [Indexed: 12/28/2022] Open
Abstract
Fully digital workflows gained acceptance in dental practice and thereby are of interest for undergraduate education. An exploratory clinical observation was designed to track the implementation of such a workflow with novice digital users in order to describe its feasibility, time investment, and pitfalls. METHODS Students were invited to provide feedback for their experiences with a training module that consisted of the following: intraoral scanning, computer-aided design (CAD), manual finishing, and insertion of a 3D-printed bite splint for the lower jaw. RESULTS A total of 82 fourth-year students participated in the module. The average time required to perform an intraoral scan was 17 m 5 s, and all students were able to design a splint with an average time of 2 h 38 m. Students who indicated prior experience with CAD seem to outperform inexperienced students in both CAD task completion and intraoral scanning. The initial fit was reported as clinically acceptable by 68.5% of the participants, while 79% rated the workflow as very good to satisfactory and indicated that the training was helpful for dental practice. CONCLUSIONS The implementation of a digital workflow in undergraduate dental education is feasible and has acceptable clinical results. However, CAD is time-intensive, and the experience can be challenging.
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Obturator Manufacturing for Oronasal Fistula after Cleft Palate Repair: A Review from Handicraft to the Application of Digital Techniques. J Funct Biomater 2022; 13:jfb13040251. [PMID: 36412892 PMCID: PMC9680338 DOI: 10.3390/jfb13040251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/09/2022] [Accepted: 11/15/2022] [Indexed: 11/19/2022] Open
Abstract
An oronasal fistula (ONF) is an abnormal structure between the oral and nasal cavities, which is a common complication of cleft palate repair due to the failure of wound healing. When some patients with ONF are unsuitable for secondary surgical repair, the obturator treatment becomes a potential method. The objectives of the obturator treatment should be summarized as filling the ONF comfortably and cosmetically restoring the dentition with partial function. The anatomy of patients with cleft palate is complex, which may lead to a more complex structure of the ONF. Thus, the manufacturing process of the obturator for these patients is more difficult. For performing the design and fabrication process rapidly and precisely, digital techniques can help, but limitations still exist. In this review, literature searches were conducted through Medline via PubMed, Wiley Online Library, Science Direct, and Web of Science, and 122 articles were selected. The purpose of this review was to introduce the development of the obturator for treating patients with ONF after cleft palate repair, from the initial achievement of the obstruction of the ONF to later problems such as fixation, velopharyngeal insufficiency, and infection, as well as the application of digital technologies in obturator manufacturing.
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