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1.
Evid Based Dent ; 21(4): 138-139, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33339976

RESUMO

Source of funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectorsType of study/design Randomised controlled trial (RCT) with parallel design.Subjects This RCT was conducted at the Clinic of Fixed and Removable Prosthodontics and Dental Material Science, Centre of Dental Medicine, University of Zurich, Zurich, Switzerland. Ten patients, six women and four men, with a mean age of 62 years and an age range of 49-77 years, requiring posterior tooth-supported 3-unit fixed partial dentures (FPDs) were included in this RCT. The abutment teeth were six molars and six premolars in the maxilla and five molars and three premolars in the mandible. The patients fulfilled the following inclusion criteria: they all were >18 years, with a full mouth plaque score <25% and a full mouth bleeding score <25%. They all needed a posterior tooth-supported FPD, in which the third molar was not an abutment tooth. Only abutments with no extensive pretreatment were eligible. Adjacent and opposing teeth should be healthy or adequately restored.Treatment Three intraoral digital scanning systems (Lava C.O.S.; 3M [Lava], iTero; Align Technology Inc [iTero], Cerec Bluecam; Dentsply Sirona [Cerec]) and conventional light/regular body polyether impression in a stock tray were made on each of the included participants by the same clinician. The opposing arch impression was made in alginate. The sequence of the four techniques was computer generated and concealed in opaque sealed envelopes. Three calibrated experienced clinicians were involved in the treatment. They followed the published guidelines for preparing abutments that receive CAD/CAM ceramic FPDs. After interim prosthesis removal and double retraction cord application, the digital or the conventional impression procedure was started as dictated by the random sequence. Scans were done according to the manufacturer's guidelines, whereby Lava and Cerec required powdering of the teeth by titanium oxide and iTero did not.Main outcome Time needed for obtaining a scan or an impression was calculated. For digital scans it consisted of the time required for powdering, scanning and occlusal registration, while in conventional impression it started from the beginning of impression mixing till tray removal. The number of impression or scan remakes required until results fulfilling the quality criteria were obtained was also recorded. Visual analogue scale (VAS) was used to rate the perception of both, clinicians and patients for the procedures. Patients were asked to rate their comfort with the procedure, while clinicians rated both difficulty and comfort, where 0 indicated uncomfortable and simple and 100 difficult and comfortable. Subjective assessment of the time as judged by the clinicians and the patients was also reported.Main results Generally speaking, conventional impression was better than the three complete arch digital scans, regarding time required in seconds, difficulty for clinicians, comfort and time perception of both patients and clinicians. Number of remakes were highest in iTero (7), followed by Lava, conventional impression and finally Cerec (0). The time required for each technique differed significantly Polyether = 658 (95%CI 528-782) Cerec = 1776 (95%CI 804-2386) iTero = 1107 (785 - 2091). A significant difference was found neither among the three digital impressions, nor between the conventional impression and Lava (µ = 1091, 95%CI [717-1465]). The same findings were reported regarding difficulty for the clinicians. A significant difference was reported between conventional impression (µ = 15, 95%CI [7-24]) and both Cerec (µ = 67, 95%CI [58-77]) and iTero (µ = 43, 95%CI [25-62]). No significant difference was reported among the studied techniques regarding patients' comfort and time perceptions of both clinicians and patients except for a difference in the patients' time perception of Cerec and conventional impression, where P = .035. Regarding the clinicians' comfort a significant difference was only found between conventional impression (µ = 82, 95%CI [69-94]) and Cerec (µ = 32, 95%CI [18-46]).Conclusion Within the limitations of this RCT, it can be concluded that complete arch conventional impression is objectively less time consuming and subjectively preferred by both clinicians and patients when compared to digital scanning. Digital scanning techniques, requiring powdering, are more difficult for the clinicians than powderless ones and conventional impression.


Assuntos
Materiais para Moldagem Odontológica , Técnica de Moldagem Odontológica , Idoso , Cerâmica , Prótese Parcial Fixa , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Suíça , Fluxo de Trabalho , Zircônio
2.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(6): 1112-1116, 2020 Dec 18.
Artigo em Chinês | MEDLINE | ID: mdl-33331323

RESUMO

OBJECTIVE: To assess the effect of disinfectant (Cavicide) with benzethon chloramine and isopropanol as main active ingredients disinfectant on dental impression accuracy. METHODS: The effect of Cavicide on three impression materials (alginate, polyether and vinylpolysiloxane) were assessed using a standard model. The standard model was digitized by an extraoral scanner (IScan D103i, Imetric). For each kind of impression materials, thirty impressions were taken following the manufactures' instruction in the same conditions. Subsequently, the impressions were randomly divided into three groups, with ten impressions in each group. After the impression taking was completed, the three groups underwent pure water rinse for 1 min (blank control, BC), 2% glutaraldehyde solution immersion disinfection for 30 min (glutaraldehyde, GD), and Cavicide solution spray disinfection for 5 min (Cavicide, CC), respectively. All the impressions were digitized by the extraoral scanner (IScan D103i, Imetric) after disinfection and exported to a dedicated three-dimensional analysis software (Geomagic Qualify 2014, Geomagic, USA). In the software, the digital models of the impressions were trimmed to teeth and then superimposed with the digitized standard model via best-fit alignment. Root mean square (RMS) was used to evaluate the deviations between the impression and the standard model. The deviation in the anterior and posterior regions was evaluated respectively. One-way ANOVA test and the LSD post-hoc test were used to compare the deviations between the three groups (P < 0.05). The color map of each superimposition was saved for visual analysis. RESULTS: For the polyether and vinylpolysiloxane materials, the difference between the three groups was not statistically significant (P=0.933, P=0.827). For the alginate material, the difference in posterior region between group GD and group BC, as well as group GD and group CC were statistically significant (GD vs. BC, P=0.001; GD vs. CC, P=0.002), while the difference between group BC and group CC was not statistically significant (P=0.854). The visual analysis showed an obvious deviation in the buccal-lingual direction in group GD. CONCLUSION: Disinfectant (Cavicide) with benzethon chloramine and isopropanol as main active ingredients using spray disinfection has no effect on the accuracy of the alginate, polyether and vinylpolysiloxane impressions.


Assuntos
Desinfetantes , 2-Propanol , Cloraminas , Materiais para Moldagem Odontológica , Técnica de Moldagem Odontológica , Modelos Dentários , Desinfecção
3.
Rev. cuba. estomatol ; 57(4): e3016, Oct.-Dec. 2020. graf
Artigo em Inglês | LILACS, CUMED | ID: biblio-1144446

RESUMO

ABSTRACT Introduction: The passivity of prosthetic components is one of the most important prerequisites in oral implant rehabilitation for maintenance of osseointegration. Objective: Thus, the present study analyzed in vitro the accuracy of different molding techniques in prosthetic rehabilitation on angled implants installed in an anatomical model of a metallic edentulous maxilla. Methods: Laboratory experiment study. A reference metal model of an edentulous maxilla was used. A metal framework was used for the misadaptation assessment. Three groups (n= 10) were compared and impressions were made with vinyl-polysiloxane and casts were obtained with type IV stone: (1) Impression with a metallic open-tray without splinted transfers; (2) Impression with a metallic open-tray and metal splinted transfers; (3) Impression with a multifunctional guide and metal splinted transfers. Misadaptation was assessed with the aid of a stereomicroscope and measuring software. Data were submitted to ANOVA with Welch correction and the Games-Howell post-hoc test with the significance set at 5 percent. Results: Misadaptation (µm) was 110,23 ± 30,94, 37,53 ± 3,92, and 37,69 ± 2,79 for the the groups. Statistically significant differences between impression with a metallic open-tray with and without splinted transfers were observed (p < 0,001). No significant differences between the other types of impression. Conclusions: Impression with a metallic open-tray without splinted transfers and with a multifunctional guide splinted with metal transfers were the most precise methods resulting in higher accuracy in transferred implants(AU)


RESUMEN Introducción: La pasividad de los componentes protésicos es uno de los prerrequisitos más importantes para el mantenimiento de la osteointegración en la rehabilitación oral sobre implantes. Objetivo: Evaluar in vitro la precisión de diferentes técnicas de impresión en rehabilitación sobre implantes inclinados instalados en un modelo anatómico de un maxilar metálico desdentado. Métodos: Estudio de laboratorio de tipo experimental. Se utilizó un modelo metálico de referencia de un maxilar desdentado. Fue utilizada una barra metálica para la evaluación de la desadaptación. Se compararon tres grupos (n = 10), se realizaron impresiones con polivinilsiloxano y se obtuvieron modelos con yeso piedra tipo IV: (1) impresión con una cubeta metálica abierta sin unión de los transferentes; (2) impresión con una cubeta metálica abierta y unión de los transferentes con cilindros metálicos; (3) impresión con una guía multifuncional y unión de los transferentes con cilindros metálicos. La desadaptación se evaluó con la ayuda de un microscopio estereoscópico y un software de medición. Los datos se enviaron a ANOVA con la corrección de Welch y la prueba post-hoc de Games-Howell con la significación establecida en 5 por ciento. Resultados: La desadaptación (µm) fue de 110,23 ± 30,94; 37,53 ± 3,92 y 37,69 ± 2,79 para los grupos, respectivamente. Se observaron diferencias estadísticamente significativas entre la impresión con cubeta abierta metálica con y sin unión de los transferentes (p <0,001). No hubo diferencias significativas entre los otros tipos de impresiones. Conclusiones: La impresión con cubeta abierta metálica sin unión de los transferentes y con una guía multifuncional con unión de los transferentes con cilindros metálicos fueron los métodos más precisos que dieron como resultado una mayor precisión en la transferencia de la posición de los implantes(AU)


Assuntos
Humanos , Implantação Dentária/métodos , Materiais para Moldagem Odontológica/efeitos adversos , Materiais Dentários/uso terapêutico
4.
J Oral Sci ; 62(4): 439-443, 2020 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-32908080

RESUMO

This study evaluated the effect of a modified tray design on the accuracy of implant impressions in comparison with the non-splinted and splinted impression techniques. Two titanium frameworks were produced to fit two parallel implants and two divergent implants with a 15o angle. According to the frameworks employed, two acrylic resin master models were fabricated. For each model, 10 impressions were taken with every technique. The maximum framework principal strain was calculated for every generated cast. For the parallel implant model, the strains of the non-splinted (118.4 µÎµ), splinted (89.0 µÎµ), and modified tray design impression (49.4 µÎµ) techniques were statistically similar (P = 0.16). For the divergent implant model, all the impression techniques showed a considerably higher strain than the parallel implant model. The splinted (287.0 µÎµ) and the modified (262.9 µÎµ) tray design impression techniques showed similar strains for the divergent implant model, which were significantly less than the strains for the non-splinted impression (518.0 µÎµ) technique (P < 0.05). Therefore, for two parallel implants, all the impression techniques exhibited similar accuracy. When angulation existed between the implants, the splinted and the modified tray design impression techniques were more accurate than the non-splinted impression technique.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Materiais para Moldagem Odontológica , Modelos Dentários , Prótese Dentária Fixada por Implante
5.
J Orofac Orthop ; 81(6): 427-439, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32897413

RESUMO

PURPOSE: This study investigates the accuracy of abutment transfer with current impression materials and provides a concise overview, including other relevant factors, in order to enable clinicians to make an informed decision about the optimal impression for this treatment procedure. METHODS: In all, 96 impressions of a cadaver head with two orthodontic miniscrews in place were taken with four common impression materials by two observers and using two methods of application. After pouring with a standard type IV stone and abutment transfer, all models and the upper jaw (which had been separated from the head) were scanned in a standard model scanner (Zirkonzahn® [Zirkohnzahn GmbH, Gais, Italy] S600 ARTI) and evaluated using a computer-aided design (CAD) program (GOM-Inspect [Gesellschaft für optische Messtechnik m.b.H., Braunschweig, Germany]). The deviations were measured at six points per screw and statistically evaluated with SPSS® (IBM, Chicago, IL, USA). RESULTS: Optimal values were obtained with biphasic polyvinylsiloxane, while monophasic polyvinylsiloxane, alginate and polyether also resulted in acceptable accuracy. Observer experience showed no effect and the method of application had only a minor effect on accuracy. CONCLUSIONS: Within the limitations of this study, it seems that all impression materials are suitable for miniscrew abutment transfer, provided that methods of intraoral adaptation of the orthodontic appliance can be employed. If higher accuracy is needed or for clinicians with less experienced, a biphasic polyvinylsiloxane impression with the putty-wash technique should be used as this combination reduces setting time. The most cost-effective version, alginate, can be used if the consequences of greater deviations can be handled. Caution is advised with polyether if undercuts are present.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Materiais para Moldagem Odontológica , Alemanha , Itália
6.
J Prosthodont ; 29(8): 660-678, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32613641

RESUMO

PURPOSE: To systematically review in vitro and clinical studies comparing quantitatively the 3D accuracy (global implant deviations) of digital vs conventional implant impressions for partially and completely edentulous patients. MATERIALS AND METHODS: Electronic and manual searches were conducted to identify in vitro and clinical studies, reporting on the 3D accuracy between digital and conventional implant impressions. Secondary outcomes were the effect of implant angulation, type of conventional impression technique, and type of intraoral scanner on the accuracy of implant impressions. RESULTS: The inclusion criteria were met by 9 in vitro studies and 1 clinical study reporting on completely edentulous impressions, while 6 in vitro and 2 clinical studies reported on partially edentulous impressions. Quantitative meta-analysis was performed for 5 completely edentulous and 6 partially edentulous studies. The studies exhibited high values for heterogeneity. A random effects model was conducted to estimate the effect size. Based on 5 in vitro studies on completely edentulous impressions, the mean 3D implant deviation between conventional and digital impressions was 8.20 µm (95% CI: -53.56, 37.15) and the digital impressions had nominally less deviation (p = 0.72). Based on 1 clinical and 5 in vitro studies on partially edentulous impressions, the mean 3D implant deviation between conventional and digital impressions was 52.31 µm (95% CI: 6.30, 98.33) and the conventional impressions had nominally less deviation (p = 0.03). Five in vitro and 2 clinical studies were not included in the quantitative analysis due to heterogeneity in the methodology. Implant angulation affected the accuracy in favor of the partially edentulous conventional impressions whereas the effect of different scanners was not statistically significant on the completely edentulous impressions (p = 0.82). CONCLUSIONS: Digital scans appear to have comparable 3D accuracy with conventional implant impressions based mainly on in vitro studies. However, clinical trials are recommended to investigate the clinical accuracy of digital scans and digitally fabricated interim or prototype prostheses, before digital implant scans can be recommended for routine clinical use.


Assuntos
Implantes Dentários , Boca Edêntula , Desenho Assistido por Computador , Materiais para Moldagem Odontológica , Técnica de Moldagem Odontológica , Modelos Dentários , Humanos
7.
Int J Prosthodont ; 33(4): 410-417, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32639701

RESUMO

PURPOSE: To evaluate the dimensional accuracy of impressions made using a new fast-setting polyether material. MATERIALS AND METHODS: A metallic reference model with two crown preparations, one inlay preparation, and three stainless steel precision balls was digitized to create a digital reference model. Sixteen one-step impressions were made for each of the four study groups, differing in impression material (regular-setting polyether [RSP] vs fast-setting polyether [FSP]) and technique (monophase vs dualphase), for a total of 64 specimens. Plaster casts fabricated from these impressions were digitized using 3D scans. Global accuracy was studied by evaluating distance and angle deviations between the replica and the reference model. Local accuracy was described in terms of trueness and precision of the aligned individual abutment tooth surfaces. RESULTS: For all impression materials and techniques, the local accuracy at the abutment tooth level was excellent. For surfaces prepared for crowns, mean trueness was < 10 µm, and mean precision < 12 µm. Inlay surfaces were associated with higher inaccuracies (mean trueness < 21 µm and mean precision < 37 µm). The greatest global inaccuracies were generally measured for the cross-arch span, with mean distance changes between -55 µm and -94 µm. For all aspects of studied accuracy, impressions with FSP were at least comparable to those fabricated with RSP. CONCLUSION: Within the limitations of this study, all tested polyether materials would allow for clinically acceptable impression making. The new fast-setting material could be an alternative to regular-setting polyether materials, especially for single crowns and small fixed partial dentures.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Coroas , Materiais para Moldagem Odontológica , Restaurações Intracoronárias
8.
Dent Med Probl ; 57(2): 191-196, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649808

RESUMO

BACKGROUND: Different techniques and impression materials are employed in the process of fabricating complete denture (CD) bases. OBJECTIVES: The aim of this study was to determine differences in the denture base retention for acrylic maxillary CDs when using 2 different techniques and impression materials. Specifically, the green stick compound impression material was used for the sectional border molding technique and this was compared to using the addition vinyl silicone impression material with the single-step technique. MATERIAL AND METHODS: A crossover study was conducted on 10 participants who were completely edentulous in the upper arch (6 men and 4 women), aged 43-70 years. The participants' trays were split into 2 treatment groups: the P-group; and the Z-group. Addition vinyl silicone was used for single-step border molding in the P-group, followed by light-body final-wash impression. For the Z-group, the green stick compound was used for sectional border molding, followed by a final wash using a zinc oxideeugenol material.To quantify the retention force of the denture base in kilograms-force, a digital force gauge was used. RESULTS: The measurements indicated significantly higher mean retention values (p = 0.000) in the P­group (4.02 ±1.66 kgf) as compared to the Z­group (1.48 ±0.90 kgf). CONCLUSIONS: The results suggest the superiority of using the single-step border molding technique in the upper arch with the addition vinyl silicone material owing to the enhanced base retention of the acrylic denture base.


Assuntos
Técnica de Moldagem Odontológica , Planejamento de Dentadura , Adulto , Idoso , Estudos Cross-Over , Materiais para Moldagem Odontológica , Prótese Total , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
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
10.
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
11.
Minerva Stomatol ; 69(2): 106-111, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32489090

RESUMO

Alginic acid is a polysaccharide widely present in the cellular walls of brown algae. Alginate is widely used as a mold material in dentistry, in the production of prostheses and in the production of positives for small-scale casting. It is also used in the pharmaceutical, cosmetic and food industries for various uses. The purpose of our study is to assess whether the chemical and physical characteristics of water can influence the characteristics and performance of these materials. These impression materials are often marketed as a powder to be mixed with water, but water is not included during the purchase. We have considered different articles, but unfortunately the results that speak of this topic are few and contain little information. We have therefore carried out a review of the present literature on Pubmed and Embase search engine. The same product used by two people with two different waters will have different characteristics. The possibility of knowing these effects could allow for more performing materials and above all for identical and reproducible materials. In conclusions, the results indicate to follow the manufacturer's instructions, and eventually turn to the use of automatic devices.


Assuntos
Alginatos , Materiais para Moldagem Odontológica , Teste de Materiais , Pós
12.
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
13.
Dent Mater ; 36(7): e241-e254, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32456949

RESUMO

OBJECTIVES: The present study aimed to evaluate the bonding between three 3D printed custom tray materials and three elastomeric impression/adhesive systems using the peel test. METHODS: Test blocks were 3D printed by three different technologies using Dental LT, FREEPRINT tray, and polylactide (PLA) tray materials. The reference test blocks were conventionally fabricated with Zeta Tray LC, a light-curing resin. The surface topographies of the four tray materials were investigated by scanning electron microscopy (SEM) analyses and roughness measurements. The peel bond strength between the four tray materials and three impression/adhesive systems, vinylsiloxanether (VSXE), vinyl polysiloxane (VPS), and polyether (PE), was measured (n=12 per group). The peeling failure modes and rupture sites were identified microscopically. RESULTS: The four tray materials featured different surface topographies. The peel bond strength was not significantly different with VSXE and PE, but PLA and the reference showed higher peel bond strength with VPS than the Dental LT and FREEPRINT tray (p<0.05). The rupture site of adhesive failure in all groups was partly at the adhesive-impression material interface and partly within the adhesive but never at the adhesive-tray material interface. SIGNIFICANCE: The 3D printed tray materials can achieve satisfactory chemical compatibility with the adhesives of VSXE, VPS, and PE. Surface topographies generated by the 3D printing technologies may affect bonding. Generally, 3D printed tray materials can provide clinically adequate bond strength with the elastomeric impression/adhesive systems. PLA is recommended for bonding with VPS when severe impression removal resistance is detected.


Assuntos
Colagem Dentária , Técnica de Moldagem Odontológica , Cimentos Dentários , Materiais para Moldagem Odontológica , Teste de Materiais , Impressão Tridimensional , Resistência à Tração
14.
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
15.
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
17.
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
18.
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
19.
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
20.
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
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