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1.
Acta Odontol Latinoam ; 33(1): 3-5, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32621592

RESUMO

The aim of this study was to compare the accuracy and precision of 3D printers used to obtain models of fixed dental prostheses. A fixed dental prosthesis preparation was scanned and reproduced by four 3D printers: RapidShape P40, Asiga MAX, Varseo, and Photon. The impressions were scanned again, and the dataset was compared to the original dataset. Mean discrepancies (µm) were 52.97±20.48 (RapidShape P40), 68.27±43.53 (Asiga MAX), 62.22±56.21 (Varseo), and 80.03±28.67 (Photon). There was no difference (p=0.314) in accuracy; however, the precision differed (p=0.015) among the 3D printers. The printers had distinct precision but did not differ in accuracy.


Assuntos
Modelos Dentários , Prótese Dentária , Impressão Tridimensional/normas , Humanos
2.
Int J Comput Dent ; 23(2): 129-138, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555766

RESUMO

AIM: Despite the expanding implementation of intraoral scanning (IOS) devices, indirect digitization of conventional impressions or casts still represents the primary access to CAD/CAM. The aim of this study was to evaluate the accuracy of data acquired from impression scans and cast scans with respect to impression material and type of cast used. MATERIALS AND METHODS: A standardized titanium model for a four-unit fixed dental prosthesis (FDP) served as a testing model. Industrial computed tomography (CT) was applied, generating a reference data set. Four different impression materials were utilized (n = 12 per material): 1) Impregum Penta (polyether/group PE); 2) Imprint 4 Penta Super Quick Heavy + Super Quick Light (polyvinyl siloxane (PVS)/group PVS-I); 3) Dimension Penta H Quick + L (PVS/group PVS-D); and 4) Imprint 4 Preliminary Penta Super Quick (PVS/group PVS-P). Data were obtained from three different model situations, ie, impressions (group IMP), unsectioned plaster casts (group UNSEC), and sectioned casts (group SEC). The surfaces were digitized three times each using a laboratory scanner. The resulting test data were superposed with the reference data using a best-fit algorithm to evaluate accuracy. Statistical analysis was conducted using the Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney tests (level of significance: P < 0.050). RESULTS: Imprint 4 Penta presented the highest overall accuracy, while Imprint 4 Preliminary Penta Super Quick displayed the poorest results. Regarding the model situation (impression scan vs cast scan), impression scans from Impregum Penta and Imprint 4 Penta showed superior results. CONCLUSION: Impression scans in combination with high-precision impression material results in the most accurate data.


Assuntos
Técnica de Moldagem Odontológica , Prótese Dentária , Desenho Assistido por Computador , Materiais para Moldagem Odontológica , Modelos Dentários , Humanos
3.
Int J Comput Dent ; 23(2): 161-181, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555769

RESUMO

AIM: The purpose of this article is to present the preliminary clinical results obtained with a novel hybrid digital-analog technique, the solid index impression protocol (SIIP), which uses a solid index to capture accurate impressions of multiple implants for the fabrication of implant-supported fixed full arches (FFAs). MATERIALS AND METHODS: This pilot study was based on five patients, each treated with a FFA supported by four implants. Three months after implant placement, impressions were taken for all patients with an intraoral scanner (IOS) (direct digital impression) and with the SIIP, using a custom tray consisting of four hollow cylinders connected with a bar. This index was linked to the implant transfers and transferred to the laboratory, and the definitive FFAs were fabricated based on it. The outcomes of the study were the passive fit of implant superstructures and the accuracy of the models generated by the SIIP, inspected using a coordinate measuring machine (CMM) and reverse engineering software, and compared with the accuracy of direct digital impressions. RESULTS: Excellent clinical precision and passive fit were obtained in all five implant-supported FFAs fabricated with the SIIP. One year after delivery, all FFAs were functional without any complication. Differences in accuracy were found between the SIIP and direct intraoral scanning. CONCLUSIONS: The SIIP seems to represent a viable option for capturing accurate impressions for the fabrication of clinically precise implant-supported FFAs with a hybrid digital-analog workflow. Further studies are needed to confirm these results.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Desenho Assistido por Computador , Modelos Dentários , Humanos , Projetos Piloto , Fluxo de Trabalho
4.
Shanghai Kou Qiang Yi Xue ; 29(1): 102-104, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-32524132

RESUMO

PURPOSE: To evaluate the accuracy of implant digital impression,in order to provide guidance in digital implant prosthesis. METHODS: According to the requirements, 115 patients undergoing implantation were randomly selected. The implantation impression cap was placed and scanned with CBCT after esteosenesis. Oral cavity was scanned to make the 3D digital implantation model. The model data were obtained by scanning the digital resin implantation models. Based on the remaining teeth, the model data and CBCT data were matched in Nobel Clinicion software. RESULTS: The implantation impression cap in the patient's CBCT was completely matched and overlapped with the digital model in all of the occlusal, coronal and sagittal planes,which meant that the position, direction and angle of the implantation in the oral cavity were exactly the same as those in the digital model made by oral scanning. CONCLUSIONS: 3D digital resin model of oral scanning printing is completely accurate and can be popularized and applied in clinic.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Desenho Assistido por Computador , Modelos Dentários , Humanos , Imageamento Tridimensional , Impressão Tridimensional , Software
5.
Compend Contin Educ Dent ; 41(6): 336-339, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32551716

RESUMO

Dental impressions are used to produce a replica of an oral structure for use as a permanent record or in the production of a dental restoration or prosthesis. Accurate impression-taking is an essential procedure in implant dentistry. Traditionally, clinicians have used two different implant impression techniques: transfer and pick-up. The pick-up impression technique is considered to be the more accurate of the two because with this technique the impression copings are maintained within the impression upon removal from the mouth, thus eliminating the potential for error that may occur when manually placing the copings in the impression as in the transfer technique. This design has become increasingly popular and useful for multi-unit impressions. The purpose of this article is to review various pick-up impression copings and propose a new impression coping design for accurate, easy impression-taking without discrepancies.


Assuntos
Implantes Dentários , Materiais para Moldagem Odontológica , Adaptação Psicológica , Dente Suporte , Técnica de Moldagem Odontológica , Modelos Dentários , Planejamento de Prótese Dentária
6.
J Contemp Dent Pract ; 21(2): 190-196, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32381826

RESUMO

AIM: The aim of the study was to evaluate the dimensional accuracy of three combinations of polyvinyl siloxane impression material by double-mix single-step impression technique. MATERIALS AND METHODS: Metal master model was made according to the ADA specification no. 19; ISO 4823:2000/AMD 2007. Impressions were made using perforated custom-made metallic trays of 2 mm and 4 mm spacing, the impression materials used were putty, heavy body, regular body and light body. A total of 30 impressions were made by single-step technique and poured in die stone to obtain resultant cast. Ten impressions were made of each combination of polyvinyl siloxane (PVS). Three dimensions (interabutment distance, height and diameter) on resultant cast were measured and compared with metal master model. The results were statistically analyzed and tabulated. RESULTS: Diameter of abutment, the height of abutment and interabutment distance in each group were larger in dimensions as compared with metal master model. The dimensional discrepancies of group I, group II and group III casts when compared with the master model were significantly different from each other. The least difference was found in group I. CONCLUSION: The one-step putty-light body combination (group I) produced the most accurate stone casts compared with one-step heavy body-light body and regular body-light body combinations. CLINICAL SIGNIFICANCE: In everyday dental practice, impression making is imperative. Hence, by doing this study, we tried to find out which material combination is suitable to give us predictable and accurate results.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Polivinil , Siloxanas
7.
J Contemp Dent Pract ; 21(3): 220-226, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32434964

RESUMO

AIM: The aim of this research was to determine whether sterilization and reutilization of impression copings had an impact on the accuracy of casts made for multiimplant restorations. MATERIALS AND METHODS: Four master casts embedded with five implant analogs were fabricated. Polyvinyl siloxane (PVS) impressions of the master cast with copings attached to the analogs were made and poured in dental stone. The impression copings were subjected to cleaning and sterilization. These processes were repeated 30 cycles for each of the two groups of five impression copings: one without modification and one with modification that included air abrasion and PVS adhesive. A coordinate measuring machine (CMM) was used to measure relative angles and distances between the reference analog and analogs. The relative angles and distances measured on the stone casts were compared to the master resin cast to obtain positional and angular displacements. RESULTS: For impression copings that were not modified, a significant difference was detected for both positional and angular displacements. For impression copings that were modified, a significant change was observed only for positional displacement. The maximum discrepancies measured for positional and angular displacements after 30 cycles of reuse were only 81 µm and 0.46°, respectively, regardless of the modification. CONCLUSION: Within the limitations of this study, unmodified impression copings that have undergone 30 cycles of cleaning and sterilization appeared to incur more impression inaccuracy than those impression copings that were modified by airborne-particle abrasion and PVS adhesive. CLINICAL SIGNIFICANCE: Impression copings used in this study can likely be recycled up to 30 times without reducing the accuracy of the impression to a level that may be considered clinically significant.


Assuntos
Materiais para Moldagem Odontológica , Técnica de Moldagem Odontológica , Adaptação Psicológica , Abrasão Dental por Ar , Cimentos Dentários , Modelos Dentários , Propriedades de Superfície
8.
Head Face Med ; 16(1): 9, 2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-32366261

RESUMO

BACKGROUND: There is no consensus in the literature regarding the impression procedures in the presence of multiple and angulated implants. METHODS: Three maxillary master models with 6 implants bilaterally positioned in anterior, premolar and molar regions were fabricated. In model 1, all implants were placed in parallel; in models 2 and 3, anterior implants were buccally inclined and posterior implants were distally inclined in 10- and 20-degrees, respectively. Three different impression copings (hexed, non-hex, multi-unit) and two different impression techniques (splinting and non-splinting) were tested. A total of 180 impressions (n = 10 per group) were made using mono-phase vinyl poly-siloxane. Master models and duplicate casts were scanned by a 5-axis laboratory scanner and data were transferred to a software program for the alignment of master and duplicate copings. Coronal and angular deviations were calculated, and data were statistically analyzed. RESULTS: For angulated models, the lowest deviation values were detected at the splinted non-hex coping group (P < 0.05). CONCLUSIONS: Implant angulation, impression coping type, and splinting the impression copings had significant effects on the accuracy of impressions. TRIAL REGISTRATION: Not applicable.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Materiais para Moldagem Odontológica , Modelos Dentários , Maxila
9.
Head Face Med ; 16(1): 11, 2020 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-32430023

RESUMO

OBJECTIVE: In-vivo accuracy of intraoral scans of complete mixed dentitions of patients in active treatment have not yet been investigated. The aim was to test the hypothesis that dimensional differences between intraoral scans and conventional alginate impressions in the mixed dentition are clinically irrelevant. METHODS: Trial design: Prospective non-randomized comparative clinical trial. Based on sample size calculation 44 evaluable mixed dentition jaws of patients in active orthodontic treatment were included. Each patient received an alginate impression following an intraoral scan (TRIOS® Ortho). Plaster cast was fabricated and scanned with an external scanner (ATOS-SO®). Both STL datasets were analyzed with the 3D inspection and mesh processing software GOM Inspect®. Statistical analysis comprised sample size calculation, t-test as well as nonparametric tests. RESULTS: The absolute mean difference between digital plaster casts and intraoral scans is 0.022 mm ± 0.027 mm (median 0.015 mm). The obtained measurements are in the range of comparable studies on full arch permanent dentitions. Gender, the size of the jaw represented by the dentition stage and upper respectively lower jaw, as well the malocclusion have no effect on the total deviations between digital plaster casts and intraoral scans. Detectable impression errors were bubbles in fissures and marginal ridges as well as incomplete alginate flow and detachment from the tray. Detectable scanning errors were incomplete distal surface of the most distal molar. CONCLUSION: Dimensional differences between intraoral scans and conventional alginate impressions in the mixed dentition are clinically irrelevant for orthodontic purposes. In all clinical situations of active treatment in the mixed dentition, the intraoral scans are more detailed and less error-prone.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Dentição Mista , Desenho Assistido por Computador , Feminino , Humanos , Imageamento Tridimensional , Masculino , Estudos Prospectivos
10.
Ned Tijdschr Tandheelkd ; 127(3): 147-151, 2020 Mar.
Artigo em Holandês | MEDLINE | ID: mdl-32343274

RESUMO

Inattention while taking dental impressions of the upper jaw of patients with a palatal defect can lead to dental impression material being left behind. Two patients with a cheilognathopalatoschisis and a full arch prosthesis in the upper jaw were referred with complaints characteristic of chronic sinusitis and recurrent epistaxis, lasting several years. A facial cone beam computer tomogram revealed dental impression material left behind in the palatal defect and the nasal cavity. In the case of both patients, the foreign bodies were removed under general anaesthesia. One of the patients twice brought up a residual fragment of dental impression material left in the palatal defect after surgery.


Assuntos
Fenda Labial , Materiais para Moldagem Odontológica , Técnica de Moldagem Odontológica , Modelos Dentários , Humanos , Maxila
11.
Eur J Prosthodont Restor Dent ; 28(2): 75-85, 2020 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-32347671

RESUMO

PURPOSE: To compare the accuracy of 6 desktop 3D printers in dentistry. METHODS: A parallelepiped (PP) with known geometry and holes of different diameters was designed and printed with 6 desktop 3D printers (Sheraprint 40®; Solflex 350®; Form 2®; MoonRay D75®; Vida HD®; XFAB 2000®). For each printer, 9 PPs were printed with proprietary materials; these PPs were not cured and underwent dimensional analysis by optical microscopy and precision probing. A file representative of a dentate model (DM) was also printed with the aforementioned printers. For each printer, 3 DMs were printed with the proprietary materials. These DMs were cured and after 1 month, scanned with a desktop scanner and superimposed on the virtual reference model, to investigate trueness. RESULTS: Dimensional analysis by optical microscopy and precision probing highlighted the reliability of the 3D printed models; errors were compatible with clinical use. However, both linear and diameter measurements revealed statistically significant differences between the machines. The trueness of the DMs 1 month after printing was low, suggesting that they underwent dimensional contraction over time, albeit with differences between the printers. CONCLUSIONS: The 3D printed models showed acceptable accuracy, although statistically significant differences were found among them.


Assuntos
Modelos Dentários , Impressão Tridimensional , Odontologia , Reprodutibilidade dos Testes
12.
Compend Contin Educ Dent ; 41(3): 178-179, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32125171

RESUMO

Impression-making is a necessary part of providing restorative and rehabilitative dentistry to patients. The use of physical impression trays and materials dates back to at least the 19th century, which included the development of corrective and functional impression techniques.1 This method of acquiring and conveying information remained largely unchanged throughout the 20th century, although the development and subsequent improvement of elastomeric impression materials greatly enhanced the quality and predictability of impression results. Now with the digitization of the dental profession, the introduction and advancement of digital impressions represents the latest step forward in impression-making. This article reviews the current state of physical impression-making and the.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Materiais para Moldagem Odontológica , Humanos
13.
J Prosthodont ; 29(4): 281-286, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32166793

RESUMO

PURPOSE: A prospective clinical study to compare for the first time the accuracy of digital and conventional maxillary implant impressions for completely edentulous patients. MATERIALS AND METHODS: Sixteen patients received maxillary implant supported fixed complete dentures. After the verification of the conventional final casts, the casts were scanned with a desktop (extraoral) scanner. Intraoral full-arch digital scans were also obtained with scan bodies and STL files. Extraoral and intraoral scans were superimposed and analyzed with reverse engineering software. The primary outcome measure was the assessment of accuracy between scans of the verified conventional casts and digital full-arch impressions. The secondary outcome was the effect of the implant number on the 3D accuracy of impressions with Spearman's rank correlation coefficient. RESULTS: The 3D deviations between virtual casts from intraoral full-arch digital scans and digitized final stone casts generated from conventional implant impressions were found to be 162 ± 77 µm. In the 4-implant group, 5-implant group, and 6-implant group the 3D deviations were found to be 139 ± 56 µm, 146 ± 90 µm, and 185 ± 81 µm, respectively. There was a positive correlation between increased implant number and 3D-deviations, but there was no statistically significant difference (p = 0.191). CONCLUSIONS: The 3D accuracy of full-arch digital implant scans lies within previously reported clinically acceptable threshold. Full-arch digital scans and a complete digital workflow in the fabrication of maxillary fixed complete dentures may be clinically feasible.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Desenho Assistido por Computador , Materiais para Moldagem Odontológica , Modelos Dentários , Humanos , Imageamento Tridimensional , Maxila , Estudos Prospectivos
14.
Am J Orthod Dentofacial Orthop ; 157(3): 348-356, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32115113

RESUMO

INTRODUCTION: The purpose of this study was to investigate the registration accuracy between intraoral-scanned crowns and cone-beam computed tomography (CBCT)-scanned crowns in various registration methods. METHODS: The samples consisted of 18 Korean adult patients, whose pretreatment intraoral scans and CBCT images were available. A 3-dimensional (3D) dental model was fabricated using a TRIOS intraoral scanner (3Shape, Copenhagen, Denmark) and the OrthoAnalyzer program (version 1.7.1.4; 3Shape). After the CBCT image was taken, 3D volume rendering was performed to fabricate a 3D dental model using InVivo5 software (version 5.1; Anatomage, San Jose, Calif). Registration of the 3D dental crowns made from intraoral- and CBCT-scanned images was performed with Rapidform 2006 software (Inus Technology, Seoul, Korea) by a single operator. According to registration methods, 3 groups were established: individual-arch-total-registration group, individual-arch-segment-registration group, and bimaxillary-arch-centric-occlusion-registration group (n = 18 per group). After the amounts of shell/shell deviation were obtained, the mixed model analysis of variance and Bonferroni correction were performed. RESULTS: Although there was no significant difference in the registration accuracy between the individual-arch-total-registration group and individual-arch-segment-registration group, the bimaxillary-arch-centric-occlusion-registration group exhibited the lowest registration accuracy (maxillary and mandibular teeth, all 0.21 mm in the individual-arch-total-registration group; all 0.20 mm in the individual-arch-segment-registration group vs 0.26 mm and 0.25 mm in the bimaxillary-arch-centric-occlusion-registration group; P <0.001). Color-coded visualization charts exhibited that most red spots were localized on the occlusal surface of the posterior teeth in all 3 groups. CONCLUSIONS: When considering the registration accuracy and convenience of the process, the individual-arch-total-registration method can be regarded as an efficient tool when integrating CBCT-scanned crown and intraoral-scanned crown.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Modelos Dentários , Adulto , Coroas , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , República da Coreia
15.
Am J Orthod Dentofacial Orthop ; 157(3): 422-428, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32115120

RESUMO

INTRODUCTION: This study aimed to investigate whether a digital light processing (DLP) printer could perform efficiently and with adequate accuracy for clinical applications when used with different settings and variations in the orientation of models on the build plate. METHODS: Digital impressions of the oral environment were collected from 15 patients. Subsequently, digital impressions were used to make 3-dimensional printed models using the DLP printing technique. Three variables of the printing technique were tested: placement on the build plate (middle vs corner), thickness in the z-axis (50 microns vs 100 microns), and hollow vs solid shell. After being printed with different printing techniques and orientations on the same printer, a total of 240 maxillary and mandibular arches were measured. These variables generated 8 printing combinations. Tooth and arch measurements on each model type were compared with each other. Intraobserver reliability of the repeated measurement error was assessed using intraclass correlation coefficient. RESULTS: All mean differences among the printing variations were statistically insignificant. The Bland-Altman plots verified a high degree of agreement among all model sets and printing variations. In addition, the measurements were highly reproducible; this was demonstrated by the high intraclass correlation coefficient for all measurements recorded. CONCLUSIONS: The DLP printer produced clinically acceptable models in all areas of the build plate, with hollow and solid model shells, and at its high-speed setting of 100 microns. The applications of the DLP printer tested should be a viable option for printing in a clinical environment at a high-speed setting while filling the build plate and printing with less resin.


Assuntos
Modelos Dentários , Impressão Tridimensional , Dente , Humanos , Maxila , Reprodutibilidade dos Testes
16.
Int J Comput Dent ; 23(1): 49-56, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32207461

RESUMO

AIM: Evaluation of appropriate models for computer-aided design/computer-aided manufacturing (CAD/CAM) in vitro studies by investigation of different model materials regarding suitability for intraoral scanners and dimensional stability. MATERIALS AND METHODS: A typodont model was prepared to accommodate a 10-unit prosthesis. The model was duplicated using six different materials: class IV die stone (DS), cobalt-chrome molybdenum (CoCrMo), epoxy resin (EPOX), polyurethane (PU), titanium (TI), and zirconia (ZI). An intraoral scanner was used to obtain three scans of each model. Reference datasets were generated using micro-computed tomography (micro-CT). The first scan was compared with the corresponding reference micro-CT dataset to assess its trueness. The precision was measured by comparing all scans within one test group. For the evaluation of dimensional stability, micro-CT was used to generate three-dimensional (3D) datasets of the models at different time intervals over a 6-week period. The models were kept under constant conditions during the study. All datasets were analyzed with software that determined the deviation of two datasets by alignment using a best-fit algorithm. RESULTS: The criterion of trueness was fulfilled by CoCrMo, EPOX, PU, and the typodont model. Scans of CoCrMo and ZI showed the best precision. PU and the typodont model did not meet the requirement of dimensional stability, whereas EPOX and gypsum were stable only for a period of 10 days. CONCLUSION: The CoCrMo model was the only one that met all the criteria for an appropriate model for CAD/CAM in vitro studies. The other investigated materials either lacked dimensional stability or could not be scanned accurately and reproducibly.


Assuntos
Desenho Assistido por Computador , Adaptação Marginal Dentária , Ligas de Cromo , Técnica de Moldagem Odontológica , Modelos Dentários , Humanos , Imageamento Tridimensional , Titânio , Microtomografia por Raio-X
17.
Niger J Clin Pract ; 23(3): 284-290, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32134024

RESUMO

Aims: The aim of this study was to determine the best approach to reduce the unfavorable change in the three different dimensions of impressions using disinfection durations of 15 and 30 min; three different disinfection procedures; and alginate impression products as research factors. Materials and Methods: CA37, impressional, and cream alginate impressions were used; distortion in the AB, AC, and BC dimensions of impressions using disinfection durations of 15 and 30 min was studied; and no disinfection (ND), conventional disinfection (CD), and sonicator-activated disinfection (SAD) procedures were measured. Results: Regarding AB dimension, the impressional has best performance when CD was applied for both 15 and 30 min. When SAD was applied for 15 min, impressional and cream alginates provide best performance. When CD was applied for 15 min, CA37 and impressional alginates provide best performance. Although ND-applied CA37 alginate after 30 min provides best performance, because of many outlier values, its implication may not be considered as meaningful. Regarding AC dimension, cream alginate has best performance when CD was applied for 15 min. The AC distances in all the alginates are considerably different from the base model after 30 min. Regarding BC dimension, only the CA37 alginate has the best performance when ND was applied for 15 min. All the alginates are considerably different from that of the base model after 30 min. Conclusion: Preference of 15-min disinfection can provide favorable results to obtain all impressions with minimally distorted dimensions. CD is an adequate procedure. The studied SAD needs to be developed further. All alginates are comparably successful to obtain impressions with desired distortion degrees.


Assuntos
Alginatos/química , Desinfetantes de Equipamento Odontológico/administração & dosagem , Desinfetantes de Equipamento Odontológico/química , Materiais para Moldagem Odontológica/química , Desinfecção/métodos , Esterilização/métodos , Técnica de Moldagem Odontológica , Modelos Dentários , Humanos , Controle de Infecções Dentárias/métodos , Teste de Materiais/métodos , Fatores de Tempo
18.
J Orthod ; 47(2): 149-155, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32195636

RESUMO

OBJECTIVE: To compare the measured values obtained from the plaster model, digital models created by scanning the plaster models and direct intraoral scanning with the values obtained from direct intraoral measurements. DESIGN: This was a prospective clinical study. SETTING: The study was conducted in Department of Orthodontics, Saveetha Dental College and Hospital, Tamil Nadu, India. PARTICIPANTS: Ten patients before the start of orthodontic treatment were selected for the study. METHODS: A computer-aided design and manufacturing (CAD-CAM) system is an advanced technology that is being adopted in the field of orthodontics for diagnosis, treatment planning and documentation of patient records. Mesiodistal tooth width measurements of first premolars, canines, lateral incisors and central incisors, and transverse width measurement from mesial pit of right first premolar to mesial pit of left first premolar in both maxilla and mandible were obtained from direct intraoral measurement (gold standard), study model obtained from alginate impression, intraoral scanned image, and desktop scanned image of the study model. Descriptive statistics and ANOVA was performed to find the difference in mean among the groups. RESULTS: A P value > 0.05 was obtained in ANOVA indicating that there is no statistically significant difference in the measurements obtained by either of the methods. CONCLUSION: Conventional stone models and digital models obtained from intraoral scan and desktop scanning of plaster models are clinically reliable as the variations in measurements obtained from these methods were clinically negligible.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Desenho Assistido por Computador , Humanos , Imageamento Tridimensional , Índia , Estudos Prospectivos
19.
Clin Oral Implants Res ; 31(7): 625-633, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32181919

RESUMO

OBJECTIVES: To compare the accuracy of an original and two newly designed CAD/CAM scan bodies used in digital impressions with one another as well as conventional implant impressions. MATERIAL AND METHODS: A reference model containing four implants was fabricated. Digital impressions were taken using an intraoral scanner with different scan bodies: original scan bodies for Group I (DO), CAD/CAM scan bodies without extensional structure for Group II (DC), and CAD/CAM scan bodies with extensional structure for Group III (DCE). For Group IV, conventional splinted open-tray impressions (CI) were taken. The reference model and conventional stone casts were digitalized with a laboratory reference scanner. The Standard Tessellation Language datasets were imported into an inspection software for trueness and precision assessment. Statistical analysis was performed with a Kruskal-Wallis test and Dunn-Bonferroni test. The level of significance was set at α = .05. RESULTS: The median of trueness was 35.85, 38.50, 28.45, and 25.55 µm for Group I, II, III, and IV, respectively. CI was more accurate than DO (p = .015) and DC (p = .002). The median of precision was 48.40, 48.90, 27.30, and 19.00 for Group I, II, III, and IV, respectively. CI was more accurate than DO (p < .001), DC (p < .001), and DCE (p = .007). DCE was more accurate than DC (p < .001) and DO (p < .001). CONCLUSIONS: The design of the extensional structure could significantly improve scanning accuracy. Conventional splinted open-tray impressions were more accurate than digital impressions for full-arch implant rehabilitation.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Desenho Assistido por Computador , Materiais para Moldagem Odontológica , Modelos Dentários , Imageamento Tridimensional , Cintilografia
20.
Compend Contin Educ Dent ; 41(2): 112-117, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32017588

RESUMO

The purpose of impression-taking is to attain the accurate transfer of intraoral information for extraoral use. It is a crucial step in performing a successful dental implant restorative procedure. To accurately replicate the implant position for adaptation of an abutment that will completely engage with the implant, a pick-up impression is taken with an impression coping. Several factors can affect seating of the impression coping, including soft-tissue interference, the size of the impression coping, angulation, proximity or contact with adjacent teeth, damage to the coping, misfit caused by use of other manufacturers' parts, and differences between seating in an external- versus internal-connection implant. This article presents use of a novel verification guide that is intended to ensure complete seating of the impression coping with the implant.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Adaptação Psicológica , Materiais para Moldagem Odontológica , Modelos Dentários
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