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1.
Int J Comput Dent ; 24(2): 117-123, 2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34085497

RESUMO

AIM: A technique for merging digital intraoral and CBCT scans for implant-supported complete-arch fixed dental prostheses (FDPs) is described. The aim is to improve the dimensional accuracy of intraoral scans in edentulous arches. MATERIALS AND METHOD: Two files are recorded: an intraoral scan and a CBCT scan, both obtained with scan bodies connected to the implants in the same position. The intraoral scan is then divided into several fragments and realigned, taking as reference the position of the implants recorded in the CBCT file. RESULTS: An improved intraoral digital model with corrected implant positions appropriate for complete-arch implant FDPs is generated. CONCLUSION: The methodology proposed can minimize possible intraoral scanning error and deliver more reliable digital impressions for implant-supported complete-arch FDPs.


Assuntos
Implantes Dentários , Tomografia Computadorizada de Feixe Cônico Espiral , Desenho Assistido por Computador , Técnica de Moldagem Odontológica , Modelos Dentários , Humanos , Imageamento Tridimensional
2.
Int J Comput Dent ; 24(2): 133-145, 2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34085499

RESUMO

AIM: The positional accuracy of bracket placement planned through tooth setup vs actual placement was evaluated by means of conventional thermoplastic indirect bonding trays and customized 3D-printed indirect bonding trays. MATERIALS AND METHODS: A total of 280 bracket positions placed on the crowns of 10 dental plaster models were evaluated. The manual setup method and a thermoplastic indirect bonding tray were used for the manual group. For the CAD/CAM group, the bracket was positioned using a digital setup and a corresponding 3D-printed tray. The positional accuracy of the bracket placement on the duplicated gypsum model using the trays was evaluated by means of 3D software. Six errors of bracket position (height, depth, mesiodistal, torque, rotation, and tip errors), including linear and angular errors, were measured. Differences in variables were compared across subgroups using the independent t test or the Mann-Whitney U test. RESULTS: Only the height error differed significantly (P < 0.05) between groups (manual: 0.2 mm; CAD/CAM: 0.12 mm). For both incisors and molars, the manual group showed significantly greater height errors than the CAD/CAM group (P < 0.05). The analysis of variance of the position error to the whole bracket showed statistically significant differences between tooth positions, linear measurements, and angular measurements (P < 0.05). CONCLUSION: A 3D-printed indirect bonding tray showed accuracy similar to that of conventional methods for bracket placement, with slightly greater bracket height accuracy. Further studies should strive to improve accuracy in terms of tooth positions.


Assuntos
Colagem Dentária , Braquetes Ortodônticos , Desenho Assistido por Computador , Modelos Dentários , Humanos , Impressão Tridimensional
3.
Int J Comput Dent ; 24(2): 157-164, 2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34085501

RESUMO

AIM: Dental research involves variations between actual and reference datasets of master models to determine the metric accuracy through transfer accuracy tests. Various methods of measurement are used to analyze the results, which are often subjected to direct comparisons. Hence, the aim of the present study was to analyze the influence and effect on results of different methods of digital data analysis, being coordinate-based analysis (CBA) and best-fit superimposition analysis. MATERIALS AND METHODS: A model with four implants and a reference cuboid was digitized through computed tomography (CT), which served as the master model. Ten implant impressions were made using a Trios (3Shape) intraoral scanner, and three different scan bodies (nt-trading, Kulzer, and Medentika) were used. The deviations between the master model and the digital impressions were analyzed using CBA and best-fit superimposition analysis. Statistical analysis was performed using SPSS 25. RESULTS: The deviations in the CBA and best-fit superimposition analysis ranged from 0.088 ± 0.012 mm (mean ± SE; Medentika, 14) to 0.199 ± 0.021 mm (Kulzer, 26), and from 0.042 ± 0.010 mm (Medentika, 16) to 0.074 ± 0.006 mm (Kulzer, 16), respectively. Significant differences were observed between the implant positions in the CBA and the digital measurements at each implant position, whereas the best-fit analysis showed no significant difference between the scan bodies and implant positions. CONCLUSION: CBA displays an advantage over best-fit superimposition analysis in the detection of possible influencing factors for primarily scientific purposes. However, a global analysis and visualization of angles and torsions is difficult, for which a best-fit evaluation is needed. However, a best-fit analysis better represents the clinical try-in. It is associated with the risk that possible disturbing factors and resulting errors might be leveled out and their identification camouflaged.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Desenho Assistido por Computador , Análise de Dados , Materiais para Moldagem Odontológica , Modelos Dentários , Humanos , Imageamento Tridimensional
4.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 56(6): 570-575, 2021 Jun 09.
Artigo em Chinês | MEDLINE | ID: mdl-34098673

RESUMO

Objective: To comparatively evaluate the scan time and the accuracy of maxillary full-arch scans using four intraoral scanners (IOS) on conditions of the intraoral head-simulator and the hand-held model, and to evaluate the influence of different scanning conditions on digital scan. Methods: A upper dental arch model with melamine-formaldehyde resin teeth and silica gel gingiva that could be fixed on a head simulator was scanned with an optical scanner (ATOS Core) in order to obtain the standard tessellation language dataset as reference. Intraoral scans were performed on the model fixed on the head simulator by three researchers with four IOS [A: TRIOS 3; B: CS 3600; C: CEREC Omnicam; D: iTero]. For each scanner and each researcher, six scans were performed, to obtain the datasets as the head simulator group. And another six scans with each of the four intraoral scanners were performed by each researcher on the hand-held model to obtain the STL datasets as the hand-held group. The scan time were recorded for each scan. In the Geomagic Wrap software, the digital models were trimmed with only the teeth information retained and supreimposed by best fit alignment function and compared to obtain the root mean square (RMS) values of the discrepancies by three-dimensional compare function. The test datasets of each group were compared with the reference dataset for trueness. The six test scanning datasets with the same scanner of the same researcher were cross compared for precision. Mann Whitney U test was used to statistically analyze the difference values of the scan time, trueness and precision of the same intraoral scanner between head simulator group and hand-held group. Results: Compared to the hand-held group, the scan time of A [142(82) s] and D [119(52) s], which two IOS both with handle, were longer in head simulator group [A: 98(28) s; D: 85(22) s] (P<0.01). However there were no significant differences between the two groups for scan time of IOS B and C (P>0.05). For full-arch scan accuracy (trueness and precision), there were no significant differences between the two groups of IOS A and B (P>0.05), while the trueness of C (P<0.05) and the precision of D (P<0.01) were better in head simulator group [C: 112(38) µm; D: 43(13) µm] compared to hand-held group [C: 135(47) µm; D: 53(18) µm]. However, there were no significant differences for the precision of C (P>0.05) and the trueness of D (P>0.05). Conclusions: The scan time and the accuracy of full-arch digital scans with different IOS may be effected by the scan conditions. For in vitro study of intraoral scanning, head-simulator can simulate the intraoral environment of the real patient to some extent. Meanwhile, the position of the dentist and the patient, and also the limited intraoral space during intraoral scanning are also simulated.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Desenho Assistido por Computador , Arco Dental , Humanos , Imageamento Tridimensional
5.
Int J Oral Maxillofac Implants ; 36(3): 442-449, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34115056

RESUMO

PURPOSE: To investigate the effect of implant angulation, non-free-end partial edentulism, and number of scan bodies on the accuracy of digital impressions of multiple implants in partially edentulous arches. MATERIALS AND METHODS: Four reference models of partially edentulous mandibles with implants (RM1, RM2, RM3, and RM4) representing different intraoral situations were each scanned 10 times by an intraoral scanner. Reference scans were obtained by a laboratory scanner. Test scans were compared with reference scans to obtain the distance deviations (Δd) and angular deviations (Δθ) between scan bodies for trueness assessment. Differences among the repeated test scans of each model were measured and recorded as Δdp and Δθp for precision assessment. The Student t test (α = .05) was used to compare Δd, Δθ, Δdp, and Δθp of different reference models, including RM2 vs RM1 (effect of non-free-end partial edentulism), RM3 vs RM1 (effect of implant angulation), and RM4 vs RM1 (effect of number of scan bodies). RESULTS: The implant with 17-degree angulation in RM3 showed significantly lower Δd, Δθ, and Δθp compared with the parallel implant in RM1 (Δd: P = .0382, Δθ: P = .0267, Δθp: P = .0417). The RM2 of non-free-end partial edentulism had lower distance and angular deviations than RM1, but without a significant difference. The number of scan bodies had no significant effect on the Δd, Δθ, Δdp, and Δθp of RM4 and RM1. CONCLUSION: Angulated implants showed better accuracy of digital impressions in partially edentulous arches compared with parallel implants. Non-free-end partial edentulism was attributed to improved accuracy, while the number of scan bodies showed no effect.


Assuntos
Implantes Dentários , Boca Edêntula , Desenho Assistido por Computador , Técnica de Moldagem Odontológica , Modelos Dentários , Humanos , Imageamento Tridimensional
6.
Int J Oral Maxillofac Implants ; 36(3): 530-537, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34115068

RESUMO

PURPOSE: The purpose of this study was to evaluate in vitro the accuracy of different splinting techniques using transfers combined with different tray types. MATERIALS AND METHODS: The research group fabricated a maxillary master cast with four implants and a passive metallic bar on this master cast. For the impression techniques, 48 casts were used with six different impression techniques: (1) metal tray with resin splinted transfers, (2) metal tray with metal and resin splinted transfers, (3) plastic tray with resin splinted transfers, (4) plastic tray with metal and resin splinted transfers, (5) multifunctional guide with resin splinted transfers, and (6) multifunctional guide with metal and resin splinted transfers (n = 8) using polyvinyl siloxane impression material. This study used a passive metallic bar to measure the malalignment between the framework and the analogs (A, B, C, and D) in 2D and 3D. The master and experimental casts were scanned with a contact scanner to compare the accuracy in 3D impression techniques. Discrepancies between the analogs were measured in three x-, y-, and z-axes. RESULTS: There was no statistically significant difference (P > .05) between the groups in vertical malalignments (2D). In the 3D evaluation, for the z-axis and combination of xz-axis, plastic tray with metal, and resin splinted transfers (z = 487 µm; xz = 888 µm), there was a statistically significant difference compared with the multifunctional guide and resin splinted transfers (z = 772 µm; xz = 1,380 µm). When analyzing by analog, in C, the multifunctional guide with metal and resin splinted transfers (302 µm) presented a statistically significant difference compared with the multifunctional guide and resin splinted transfers (492 µm). CONCLUSION: The evaluation methods for the accuracy impression technique presented different results between them. There was no difference in vertical malalignments (2D), but in 3D, the bonding with metal and acrylic resin presented better results than the bond with only acrylic resin when using the plastic tray and multifunctional guide, respectively, in the z-axis and the combination between the xz-axes. The bonding technique of the transfers with metal and acrylic resin presents better results in the 3D analysis for the multifunctional guide impressions.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Materiais para Moldagem Odontológica , Modelos Dentários
7.
F1000Res ; 10: 180, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33968366

RESUMO

Background: Due to advances in digital technology, it is possible to obtain digital dental models through intraoral scanning. The stereolithographic data collected from the scanner can subsequently be printed into a three-dimensional dental model in resinic material. However, the accuracy between digital dental models and printed dental models needs to be evaluated since it might affect diagnosis and treatment planning in orthodontic treatment. This study aimed to evaluate the accuracy of digital models scanned by a Trios intraoral scanner and three-dimensional dental models printed using a Formlabs 2 3D printer in linear measurements and Bolton analysis. Methods: A total of 35 subjects were included in this study. All subjects were scanned using a Trios intraoral scanner to obtain digital study models. Stereolithographic data from previous scanning was printed using a Formlabs 2 3D printer to obtain printed study models. Mesiodistal, intercanine, intermolar, and Bolton analysis from all types of study models were measured. The intraclass correlation coefficient was used to assess intraobserver and interobserver reliability. All data were then statistically analyzed. Results: The reliability tests were high for both intraobserver and interobserver reliability, which demonstrates high reproducibility for all measurements on all model types. Most of the data compared between study models showed no statistically significant differences, though some data differed significantly. However, the differences are considered clinically insignificant. Conclusion: Digital dental models and three-dimensional printed dental models may be used interchangeably with plaster dental models for diagnostic and treatment planning purposes. Keywords: Accuracy, 3D printing, digital dental model, printed dental model.


Assuntos
Modelos Dentários , Impressão Tridimensional , Humanos , Reprodutibilidade dos Testes
8.
Int J Comput Dent ; 24(1): 29-40, 2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-34006061

RESUMO

AIM: The purpose of this study was to compare the accuracy of intraoral scanning on a tooth model according to four finish line conditions (supragingival, equigingival, subgingival, and subgingival with gingival cord). MATERIALS AND METHODS: To simulate the clinical situation, the abutment was fabricated using ceramic materials. A pigment was added to the transparent orthodontic silicone to create a translucent gingiva. A CAD reference model (CRM) was obtained using a contact scanner. Finish lines on the tooth preparation were placed at the subgingival (0.5 mm below the level of the gingiva), equigingival, and supragingival (0.5 mm above the level of the gingiva) locations. In addition, a gingival cord was packed into the gingival sulcus below the subgingival finish line. A CAD test model (CTM) was obtained using two types of intraoral scanners (IOSs), i500 (Medit) and EZIS PO (DDS; N = 20 per locations). CRM and CTM were superimposed and analyzed using 3D analysis software. In the statistical analysis, the comparison of accuracy according to the finish line locations was confirmed by one-way ANOVA (α = 0.05). The differences between the groups were analyzed using the Tukey HSD post-hoc test. RESULT: There was a significant difference in the accuracy of intraoral scanning according to the finish line locations of the tooth preparations (P < 0.001). The equigingival and subgingival finish lines showed poor accuracy. The use of gingival cords significantly improved the accuracy (P < 0.05). There were significant differences between the two types of IOSs, with the i500 showing better accuracy than the EZIS PO (P < 0.001). CONCLUSION: Supragingival finish lines or the use of gingival displacement cords is recommended for clinically acceptable accuracy (< 100 µm) of the marginal region captured with an IOS.


Assuntos
Técnica de Moldagem Odontológica , Dente , Desenho Assistido por Computador , Modelos Dentários , Humanos , Dente/diagnóstico por imagem , Preparo do Dente
9.
Int J Oral Implantol (Berl) ; 14(2): 157-179, 2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-34006079

RESUMO

PURPOSE: To evaluate the accuracy of full-arch digital implant impressions taken using intraoral scanners and analyse the related variables. MATERIALS AND METHODS: An electronic search of studies on the accuracy of digital implant impressions in fully edentulous arches from 1 January 2012 to 29 February 2020 was conducted in PubMed, EMBASE and the Cochrane Library. Only peer-reviewed experimental or clinical studies written in English were included. Studies assessing the accuracy of restorations, case reports, clinical reports, technical reports and reviews were excluded. The literature screening, article reading and assessment of risk of bias were carried out by two reviewers. The data on the study characteristics, accuracy outcomes and investigated variables were extracted. RESULTS: After removal of duplicates, a total of 166 studies were identified, of which 42 were initially selected for full-text reading and 30 were included in the final analysis (29 in vitro studies and one in vivo study). The trueness of digital implant impressions ranged from 7.6 to 731.7 µm, and the precision ranged from 15.2 to 204.2 µm. Angular deviations were between 0.13 and 10.01 degrees. Considering 100 µm and 0.4 degrees as clinically acceptable levels of deviation, 18 studies reported linear/distance/3D deviations larger than 100 µm and only two studies reported angular deviations below 0.4 degrees. The effect of interimplant distance/length of the arch scanned/scanning sequence/scanning range/implant position (nine studies), implant angulation (ten studies), implant depth (five studies), implant connection (two studies), operator experience (six studies), scan body type (three studies), intraoral scanner type (six studies), scanning strategy (two studies) and modification technique (three studies) was investigated. CONCLUSIONS: Based on the results of the included studies, full-arch digital implant impressions taken using intraoral scanners are not sufficiently accurate for clinical application. Accuracy varies greatly with interimplant distance, scan body type, intraoral scanner type and operator experience, whereas implant angulation, implant connections and implant depth have no effect. The effects of scanning strategy and modification technique need further investigation.Conflict-of-interest statement: The authors declare there are no conflicts of interest related to this study.


Assuntos
Implantes Dentários , Boca Edêntula , Desenho Assistido por Computador , Técnica de Moldagem Odontológica , Modelos Dentários , Humanos
10.
Biomed Res Int ; 2021: 6674400, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33969123

RESUMO

The objective of this paper was to evaluate the existence of golden percentage in natural maxillary anterior teeth with the aid of 3D digital dental models and 2D photographs. And to propose regional values of golden percentage for restoration of maxillary anterior teeth. For this purpose, one hundred and ninety dentate subjects with sound maxillary anterior teeth were selected. Standardized frontal images were captured with DSLR, and the apparent width of maxillary anterior teeth was measured utilizing a software on a personal laptop computer. Once the dimensions were recorded, the calculations were made according to the golden percentage theory (GPT). The data were analyzed by independent and paired T-test. The level of significance was set at p < 0.05. The golden percentage values were not found in this study. The values obtained were 16%, 15%, 20%, 20%, 15%, and 16% moving from the right canine to the left canine teeth. There was no significant gender difference in the golden percentage values. Thus, golden percentage should not be used solely for the correction of anterior teeth or for determining dental attractiveness. Emphasis should be given to a range of dental proportion on regional basis.


Assuntos
Modelos Dentários , Imageamento Tridimensional , Maxila/diagnóstico por imagem , Fotografação , Dente/diagnóstico por imagem , Feminino , Humanos , Masculino , Adulto Jovem
11.
J Orthod ; 48(1): 13-23, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33843329

RESUMO

OBJECTIVES: To assess the transfer accuracy of three-dimensional (3D) printed transfer trays and compare them with transfer trays made up of polyvinyl siloxane (PVS) for use in indirect bonding. DESIGN: This was a two-arm parallel prospective randomised controlled trial. SETTING: The trial was undertaken at the outpatient department of a dental college. PARTICIPANTS: A total of 30 patients (18 men, 12 women) were randomly allocated to two groups. METHODS: The inclusion criteria included patients with permanent and fully erupted dentition (age range = 17-24 years), Angles class I malocclusion with crowding <3 mm requiring non-extraction treatment, good oral hygiene and no previous history of orthodontic treatment. Blinding was applicable only for outcome assessment. Indirect bonding was performed by the primary investigator for both the groups. Digital images of the pre-transfer and post-transfer brackets were obtained by means of an intra-oral scanner and compared using software. Superimpositions of pre- and post-transfer images were done to determine the transfer error for linear and angular variables for all tooth types. RESULTS: A total of 600 teeth were bonded, 300 each for both groups. Statistically significant differences were observed in all dimension between the two groups, with 3D-printed trays being more accurate than PVS trays except in the vertical dimension (P < 0.05). The prevalence of clinically unacceptable transfer errors revealed that most of the transfer errors were in the vertical dimensions for 3D-printed trays. CONCLUSION: 3D-printed trays are more accurate than PVS trays except for transfers in vertical dimension.


Assuntos
Colagem Dentária , Má Oclusão Classe I de Angle , Braquetes Ortodônticos , Adolescente , Adulto , Modelos Dentários , Feminino , Humanos , Masculino , Estudos Prospectivos , Adulto Jovem
12.
Chin J Dent Res ; 24(1): 61-66, 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33890457

RESUMO

OBJECTIVE: To verify horizontal jaw relations using anatomical marks on a cast and evaluate the efficiency and accuracy of the test on checking the horizontal relation. METHODS: A total of 200 patients with a loss of posterior occlusion were recruited. After casts were made and the horizontal jaw relation was recorded, the pterygomaxillary notch and retromolar pad were identified bilaterally on the maxillary and mandibular casts. On each cast, a vertical line was drawn to bisect the anatomical landmarks and the distance between the two vertical lines was measured. Using the result of the wax try-in appointment and the corresponding measurements, a diagnostic test was conducted. A receiver operating curve was created and the maximum horizontal distance between bisecting points that still obtained correct jaw relations was determined to be a criterion. The accuracy of the test to verify horizontal jaw relations was evaluated. RESULTS: The area under the curve of the receiver operating curve was 0.833 (P < 0.05). With a maximum Youden index, the d value threshold was 1.0 mm. Using 1.0 mm as a criterion to check the horizontal relation, the sensitivity of the test was 0.76 and the specificity was 0.93. The kappa value for different researchers was calculated to be 0.79 (P < 0.05). The intraexaminer 1 reliability gave a kappa value of 0.76 (P < 0.05), and intraexaminer 2 gave a value of 0.81 (P < 0.05). CONCLUSION: The test for verifying the accuracy of horizontal jaw relations is reliable. If horizontal distance is measured as greater than 1.0 mm at the jaw relation record appointment, the recorded horizontal jaw relationship may be wrong and need to be reexamined.


Assuntos
Modelos Dentários , Testes Diagnósticos de Rotina , Humanos , Registro da Relação Maxilomandibular , Mandíbula , Reprodutibilidade dos Testes
13.
Quintessence Int ; 52(6): 488-495, 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33880909

RESUMO

OBJECTIVE: This study aimed to compare the accuracy performance of five different intraoral scanning systems for a full-arch scan on an edentulous cadaver maxilla. METHOD AND MATERIALS: Five digital intraoral impression systems were used to scan a fully edentulous cadaver maxilla. A master scan obtained with an ATOS Capsule industrial grade scanner provided the point of comparison. Experimental scans were compared to the master scan using a metrology software that allows images to be overlayed on one another and deviations interpreted. Once aligned, three comparisons were made between the experimental scans and the reference: the entire maxilla, the ridge area only, and the palate area only. RESULTS: Trueness deviations between the experimental scans and the master digital model were up to 0.1 mm in the 75th percentile. For the whole maxilla, only the Medit scanner had statistically significantly inferior trueness compared to other scanners. When only the palate was considered, Medit was significantly different from Element (P = .0025) and Trios 4 (P = .0040), with no differences found between other scanners. For the ridge region the results replicate the trend observed for the whole maxilla. In regard to precision, differences were found only in the whole maxilla and the ridge area. In both areas, only Medit's precision was significantly different compared to other scanners, with the exception of Element. However, Element performance was similar to all other scanners. CONCLUSION: Most intraoral scanners exhibited similar performance. Although several statistically significant differences were identified, the clinical impact of these variances is probably not meaningful. (Quintessence Int 2021;52:488-495; doi: 10.3290/j.qi.b1244373).


Assuntos
Técnica de Moldagem Odontológica , Maxila , Desenho Assistido por Computador , Arco Dental , Modelos Dentários , Humanos , Imageamento Tridimensional , Maxila/diagnóstico por imagem
14.
Int J Prosthodont ; 34(2): 254-260, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33882570

RESUMO

PURPOSE: To assess the absolute linear distances of three different intraoral scan bodies (ISBs) using an intraoral scanner compared to a conventional impression in a common clinical model setup with a gap and a free-end situation in the maxilla. MATERIALS AND METHODS: An implant master model with a reference cube was digitized using x-ray computed tomography and served as the reference file. Digital impressions (TRIOS, 3Shape) were taken using three different ISB manufacturers: NT Trading, Kulzer, and Medentika (n = 10 per group). Conventional implant impressions were taken for comparison (n = 10). The conventional models were digitized, and all models (digital and conventional) were superimposed with the reference file to obtain the 3D deviations for the implant-abutment-interface points (IAIPs). Results for linear deviation (trueness and precision) were analyzed using pairwise comparisons (P < .05; SPSS version 25). For precision, a two-way factorial mixed ANOVA was used. RESULTS: The deviations for trueness (mean) ± precision (SD) of the IAIPs ranged as follows: FDI region 14 = 0.106 ± 0.050 mm (Medentika) to 0.134 ± .026 mm (NT Trading); region 16 = 0.108 ± 0.046 mm (conventional) to 0.164 ± 0.032 mm (NT Trading); region 24 = 0.111 ± 0.050 mm (conventional) to 0.191 ± 0.052 mm (Medentika); region 26 = 0.086 ± 0.040 mm (conventional) to 0.199 ± 0.066 mm (Kulzer). There were significant differences for trueness between all digital and conventional impression techniques. For precision, only two significant differences in two implant regions (14, 24) were observed. CONCLUSION: Longer scanning paths resulted in higher deviations of the implant position in digital impressions. Due to algorithms implemented in the software, errors resulting from the different scan bodies may be reduced during the alignment process of the IOS in clinical practice.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Desenho Assistido por Computador , Materiais para Moldagem Odontológica , Modelos Dentários , Imageamento Tridimensional
15.
BMC Oral Health ; 21(1): 105, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750357

RESUMO

BACKGROUND: Ethnic background has been claimed to affect arch form. The purpose of this study was to describe and elucidate the maxillary and mandibular arch forms in Jordanian population and to develop a classification method for these forms which could be employed to construct orthodontic archwires accordingly. METHODS: The sample was comprised of study casts of five hundred and twenty subjects (231 males and 289 females with a mean age of 15.4 ± 1.02 years). All subjects had permanent dentition with normal occlusion. A mathematical method associated with a polynomial function of 6th degree was employed to assess the dental arch forms. The resultant arch forms were classified into 5 groups for both the maxilla and mandible utilizing a computer software with special code designed for this study. Each group was subdivided into 3 subgroup sizes namely: small, medium, and large. RESULTS: Catenary arch form was found in 47% and 41.2% (p Ë‚ 0.01) of maxilla and mandible arch forms, respectively. Form 2 (which is halfway between ellipse and U-shaped arch form) was found in 27.7% and 26.7%. Medium size arch form was found in 55.4% of the maxillary and 65.6% of the mandibular arch forms. CONCLUSION: Catenary arch form was the most prevalent arch form, followed by wide elliptical form. The other forms, which included tudor arch, tapered equilateral and quadrangular forms were less frequent. Regarding size, the medium size was the most prevalent among the studied samples.


Assuntos
Arco Dental , Maxila , Adolescente , Cefalometria , Modelos Dentários , Dentição Permanente , Feminino , Humanos , Masculino , Mandíbula , Aparelhos Ortodônticos
16.
Quintessence Int ; 52(7): 636-644, 2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-33749223

RESUMO

OBJECTIVES: The goal of the study was to determine the effects of software updates on the trueness and precision of digital impressions obtained with a variety of intraoral scanner (IOS) systems. METHOD AND MATERIALS: Seven IOS systems were investigated. Each system was tested using two versions of software, with the second version being the latest at the time of conducting the study. Scans were performed on a custom mandibular typodont model with natural teeth that were either unrestored or restored with amalgam, composite, lithium disilicate, zirconia, and gold. Eight scans were obtained for each software version on any of the tested IOS systems. Experimental IOS scans were compared against an industry-standard master scan of the typodont obtained with an ATOS Capsule scanner proven to have a trueness of 3 µm and a precision of 2 µm. Isolation of each substrate material on the digital experimental and master scans was achieved using the Geomagic metrology software for subsequent analysis of the substrate influence on accuracy. A generalized linear mixed model was used to determine the influence of the software version on the trueness and precision of the impression scan. RESULTS: For some IOS systems, scans made with older software versions differ in accuracy compared with those obtained with the most recent software versions. Trueness was improved for most scanners following the software update, although the Element2 IOS performance deteriorated. Software updates had lesser effects on precision and showed variable trends among different systems. Software updates also influence different substrate materials scans' accuracy, although the results show variability among IOS systems. When comparisons were done among IOS systems updated with the latest software version, best performers for complete arch trueness were the Emerald S, Trios 3, and Primescan systems. CONCLUSION: Software updates have a statistically significant effect on the trueness and precision of different IOS systems. These updates can have both positive and negative effects on scan accuracy, although it appears that these variations are within the clinical acceptability levels.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Desenho Assistido por Computador , Arco Dental , Humanos , Imageamento Tridimensional , Software
17.
J Clin Periodontol ; 48(6): 765-773, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33576011

RESUMO

AIM: This study aimed to determine the optimal reference area for superimposition of serial 3D dental models of patients with advanced periodontitis. MATERIALS AND METHODS: Ten pre- and post-periodontal treatment 3D models (median time lapse: 13.1 months) of patients with advanced periodontitis were acquired by intraoral scanning. Superimposition was performed with the iterative closest point algorithm using four reference areas: (A) all stable teeth, (B) all teeth, (C) third palatal rugae and (D) the whole model. The superimposition accuracy was evaluated at two stable evaluation regions using the mean absolute distance and evaluated with two-way ANOVA and post-hoc multivariate model. The intra- and inter-operator reproducibility was calculated by intraclass correlation coefficient (ICC). RESULTS: Superimposition accuracy evaluated at stable tooth evaluation region were 71 ± 29 µm, 73 ± 21 µm, 127 ± 52 µm and 113 ± 53 µm for areas A, B, C and D, respectively. All reference areas showed similarly high ICC values >0.990, except for reference area C showing ICC of 0.821 (intra-operator) and 0.767 (inter-operator) for tooth evaluation area. CONCLUSIONS: Area A and B provide the highest accuracy for superimposition of serial 3D dental models acquired by intraoral scanning of patients with advanced periodontitis.


Assuntos
Imageamento Tridimensional , Periodontite , Modelos Dentários , Humanos , Palato , Periodontite/diagnóstico por imagem , Reprodutibilidade dos Testes , Técnicas de Movimentação Dentária
18.
Int J Prosthodont ; 34(1): 101-108, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33570525

RESUMO

PURPOSE: To compare the accuracy of six intraoral scanners in two different partially edentulous maxillary models and to evaluate the effect of scanning sequence on accuracy. MATERIALS AND METHODS: Maxillary Kennedy Class I and Class IV situations were used as reference models. The reference datasets were obtained by scanning the models using a highly accurate industrial scanner (ATOS Core 80, GOM). The following six intraoral scanners were evaluated: Trios 3 (3Shape), iTero Element 2 (Align Technology), Emerald (Planmeca), CEREC Omnicam (Dentsply Sirona), CEREC Primescan (Dentsply Sirona), and Virtuo Vivo (Dental Wings). A total of 120 scans from both models were obtained using the six intraoral scanners and divided into two groups based on scanning sequence. Accuracy was evaluated by deviation analysis using 3D image processing software (Geomagic Studio 12, 3D Systems). Kruskal Wallis and Mann-Whitney U tests were performed (P ≤ .05) for statistical analysis. RESULTS: There were significant differences in the accuracy of digital impressions among intraoral scanners and scanning sequences. The trueness of the Trios scanner and the precision of the Trios, Primescan, and iTero scanners were significantly higher than for the other scanners. The Emerald had the lowest accuracy among the six intraoral scanners tested. Accuracy was affected by scanning sequence when using the Virtuo Vivo, Emerald, Primescan, and iTero. CONCLUSION: In Kennedy Class I and Class IV partially edentulous cases, it is useful to consider that the intraoral scanner used may affect the accuracy of the digital impression.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Desenho Assistido por Computador , Arco Dental , Dentição , Imageamento Tridimensional
19.
Int J Prosthodont ; 34(1): 118-119, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33570527

RESUMO

Intraoral scanners have been used to capture data for the design and subsequent manufacture of dental restorations and also for registering color clinical images. Scanners can capture datasets for future use and comparisons. This manuscript describes the potential of using software algorithms to superimpose 3D images captured at different times to calculate dimensional changes at the click of a button in various dental fields. 3D patient monitoring, with the advance of artificial intelligence and its built-in capacity for data analyses, will allow dentists and researchers to calculate volumetric changes and predict potentially adverse clinical outcomes.


Assuntos
Desenho Assistido por Computador , Modelos Dentários , Inteligência Artificial , Humanos , Imageamento Tridimensional , Monitorização Fisiológica
20.
Int J Prosthodont ; 34(1): 27-36, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33570517

RESUMO

PURPOSE: To investigate the effect of training on scanning accuracy of complete arch scans (CAS) performed by first-time users, with a distinction made between specific training (repeated performance of CAS) and nonspecific training (simple use of an intraoral optical scanner for a sextant scan in the context of a CAD/CAM teaching module). MATERIALS AND METHODS: A total of 36 students with no experience in intraoral scanning were randomized into three groups (n = 12 per group) according to the number of CAS sessions: three sessions (3S), two sessions (2S), and one session (1S). Each student had to perform 10 CAS per scanning session. Sessions were scheduled at T0, T1, and T2 for group 3S; at T0 and T2 for group 2S; and at T2 for group 1S. Before the final scanning session in each group (ie, the first scanning session in group 1S), the students completed a CAD/CAM teaching module, which included fabrication of a monolithic crown in a fully digital chairside workflow. RESULTS: In all groups, repeated CAS resulted in improved scanning accuracy. Participation in the CAD/CAM module had a positive effect on initial accuracy for CAS. Mean absolute deviations in cross-arch distance were 84 µm (T0), 68 µm (T1), and 63 µm (T2) for group 3S; 79 µm (T0) and 61 µm (T2) for group 2S; and 67 µm (T2) for group 1S. CONCLUSION: To perform CAS with the best possible accuracy, specific training is highly recommended. In addition, nonspecific training leads to an improvement in initial scanning accuracy.


Assuntos
Desenho Assistido por Computador , Coroas , Técnica de Moldagem Odontológica , Modelos Dentários , Humanos , Imageamento Tridimensional , Fluxo de Trabalho
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