Tooth morphology fusion technique is more accurate than conventional technique in transferring morphology of provisional to definitive screw-retained, implant-supported crown: A preliminary intervention study.

PURPOSE: To compare the accuracy of the tooth morphology fusion (TMF) digital technique and customized impression transfer coping (conventional) technique when transferring the morphology of a provisional crown to a definitive screw-retained implant-supported crown. METHODS: Six cases of partial edentulism (one anterior and five posterior) treated with oral implant placement in our clinic for the loss of three or fewer teeth in the maxilla or mandible between April 2017 and September 2018 were included. After implant placement and re-entry surgery, provisional restorations were made and adjusted to obtain the ideal morphology. Two definitive restorations were constructed by transferring the complete morphology of the provisional restorations, including the subgingival contour, using the TMF digital and conventional techniques. Three sets of surface morphological data were obtained using a desktop scanner. The three-dimensional total discrepancy volume (TDV) between the provisional restoration (reference) and the two definitive restorations was digitally measured by overlapping the surface data of the stone cast using the Boolean operation. Each TDV ratio (%) was calculated by dividing the TDV by the volume of provisional restoration. The median TDV ratios for TMF and conventional techniques were compared using the Wilcoxon signed-rank test. RESULTS: The median TDV ratio between provisional and definitive restorations constructed using the TMF digital technique (8.05%) was significantly lower than that obtained using the conventional technique (13.56%, P < 0.05). CONCLUSIONS: In this preliminary intervention study, the TMF digital technique was more accurate than the conventional technique for the transfer of morphology from provisional to definitive prosthesis.

Three-Dimensional Printable Open-Source Cleft Lip and Palate Impression Trays: A Single-Impression Workflow.

SUMMARY: Documenting complex three-dimensional (3D) cleft lip and palate malformation with plaster casts based on maxillary impressions is standard care. Presurgical orthopedic treatment also requires an impression. Digital impression-taking in patients with cleft lip and palate is feasible, but procurement costs hinder clinical implementation. Individualized impression trays allow for a precise impression, limiting airway risk. The authors present an open-source impression tray library with scalable impression trays not requiring 3D modeling knowledge. The cleft lip and palate impression tray library is accessible on Open Science Framework. Different shapes are available, and the tray size is selected based on the tuber distance. This allows 3D printing with biocompatible material at the point of care complying with local regulations. The open-source cleft tray library presented offers a hybrid solution for cleft centers, pending the implementation of digital impression.

Influence of type of restorative materials and surface wetness conditions on intraoral scanning accuracy.

OBJECTIVES: To assess the influence of different restorative materials and surface wetness on intraoral scanning accuracy. METHODS: Reference casts with an extracted second premolar and first and second molar were digitized (L2). Four groups were established according to the material of the first molar: natural tooth (control), zirconia (Z), lithium disilicate (LD), and nanoceramic resin crown (NC). Four subgroups were developed: dry, low-, mild-, and high-wetness subgroups (n = 15). All the scans were completed by using an intraoral scanner (TRIOS 3). In the control-dry subgroup, the reference cast was dry. In the control-low subgroup, artificial saliva was sprayed with a 1 mL/min volumetric flow for 4 s. In the control-mild and control-high subgroups, the same procedures as in the control-low subgroup were performed, but with a volumetric flow of 4 and of 8 mL/min, respectively. In the Z, LD and NC groups, each crown was fabricated with its respective material. Trueness was analyzed using 2-way ANOVA and Bonferroni tests. The Levene and Bonferroni tests were used to assess precision (α = 0.05). RESULTS: Material (P < .001) and wetness (P < .001) significantly influenced trueness and precision. The mild and high subgroups revealed lower trueness and precision compared with the dry and low subgroups. The control, Z, and LD groups under dry and low wetness conditions showed better trueness compared with the NC group, but the materials tested had no significant precision discrepancies. Under mild wetness conditions, all the materials showed no significant trueness discrepancies. Under high wetness conditions, the LD group demonstrated the best trueness and precision. CONCLUSIONS: The restorative materials and surface wetness tested influenced scanning trueness and precision of the IOS assessed. CLINICAL SIGNIFICANCE: Dried surfaces are recommended to maximize the scanning accuracy values of the IOS tested. Overall, the presence of saliva and dental restorations can reduce the performance of the IOS tested.

Radiotherapy molds: An approach to fabricating facial moulage.

Impression procedures for recording large maxillofacial defects are tedious and difficult because of the unavailability of stock impression trays. This article describes the procedure of fabricating a straightforward facial moulage with predictable accuracy by using a reusable radiotherapy thermoplastic sheet.

Expanding the digital workflow for a prefabricated prelaminated fibula flap: A dental technique.

The workflow for a prefabricated prelaminated fibula free flap has been almost entirely digitized. One of the last 2 remaining steps is the impression making in stage 1 surgery. This article describes a novel computed-tomography based digital scanning technique with an assessment of the resultant accuracy.

Discrepancia anteroposterior en registro de relación céntrica con apoyo central intraoral en cubetas rodetes acrílicas (BOPAYACU) e inducción manual en adultos mayores desdentados totales / Anteroposterior discrepancy in centric relation record with intraoral central support in acylic impaction cups (BOPAYACU) and manual induction in edentulous older adults

Objetivo: Comparar la discrepancia anteroposterior medida a nivel de la platina incisiva de 2 métodos de registro intermaxilar en la misma sesión que la im-presión definitiva en adultos mayores desdentados totales. Materiales y métodos. Se incluyeron en el es-tudio 20 pacientes (n=20) con edad promedio de 70 años. En cada uno de ellos se obtuvieron registros intermaxilares con cubetas rodete de acrílico: uno con inducción manual (IM) y otro autoinducido con el sistema de cubeta rodete de acrílico y apoyo central único utilizando una superficie palatina de registro curva (BYC). Los modelos fueron montados en un ar-ticulador Whip Mix modelo 2240 al que se le adicio-nó un dispositivo de papel milimetrado, Orthodent, a nivel de la platina incisiva, para registrar las dife-rencias existentes entre las posiciones obtenidas. El análisis estadístico se llevó a cabo mediante el cálcu-lo de intervalos de confianza (95%) para las diferen-cias medias y prueba de t de student para datos apa-reados (nivel de significancia: α<0,05). Resultados. En el plano mesiodistal a nivel de la platina incisiva se encontró diferencia estadísticamente significativa entre las dos variables de registro (p<0,001). A este nivel el BYC proporcionó registros más retrusivos que IM. Media aritmética (desviaciones estándar) en milímetros: 3,82 (2,1). Conclusión. El sistema de re-gistro con cubetas rodete acrílicas y BYC incorpora-do a las mismas proporciona un registro intermaxi-lar más retrusivo que IM en adultos mayores des-dentados totales cuando se realizan dichos registros en la misma sesión que la impresión definitiva (AU)

Objective: To compare the anteroposterior discre-pancy measured at the level of the incisal plate of 2 methods of intermaxillary registration in the same session as the definitive impression in fully edentu-lous older adults. Materials and methods. Twenty pa-tients (n=20) with an average age of 70 years were included in the study. On each of them, intermaxillary recordings were obtained with acrylic rims trays: one with manual induction (MI) and the other with a self-induced system and single central support using a curved recording palatal surface (BYC). The models were mounted in a Whip Mix model 2240 articula-tor to which an Orthodent graph paper device was added, at the level of the incisal plate, to record the di-fferences between the positions obtained. Statistical analysis was carried out by calculating confidence intervals (95%) for mean differences and T-student for paired data (significance level: α<0.05). Results. On the mesiodistal plane at the level of the incisal plate, a statistically significant difference was found between the two recording variables (p<0.001). At this level the BYC provided more retrusive recordings than MI. Arithmetic mean (standard deviations) in mi-llimeters: 3.82 (2.1). Conclusions. The registration system with acrylic rim trays and BYC incorporated into them provides a more retrusive intermaxillary registration than MI in fully edentulous older adults when such registrations are made in the same ses-sion as the final impression.(AU)

Implant digital impression accuracy using extraoral scanners: a three-dimensional analysis

Aim: To analyze the accuracy of extraoral systems (Ceramill Map400+, AutoScan-DS200+, and E2) in full implantprosthetic rehabilitation three-dimensionally. Methods: A metallic edentulous maxilla with four implants was digitalized by a contact scanner (MDX-40 - Roland, control) and used as a control image to compare with other images generated by three laboratory scanners (10 samples per group). Letters identified all the four components: A and D angled 45º, and B and C parallel. The BioCAD software exported the images (.STL) to compare and verify deviations of the analogs on the X, Y, and Z axes. The nonparametric Kruskal-Wallis test and the two-way ANOVA on ranks with a post hoc Tukey test analyzed the data with 5% significance. Results: No statistical differences were observed in the accuracy between the extraoral scanners (p=0.0806). However, when analyzing only the components, component D was more accurate when scanned with Ceramill Map400+ compared with AutoScan DS200+ (p<0.001) and with E2 (p=0.002). Conclusions: All extraoral systems assessed showed digitalization accuracy but with more deviations in angled implants. The Ceramill Map400+ scanner showed the best results for the digital impression of a complete arch

Accuracy of digital auricular impression using intraoral scanner versus conventional impression technique for ear rehabilitation: A controlled clinical trial.

PURPOSE: This research aims to compare the accuracy of different auricular impression techniques used to produce either a mirror image of the unaffected ear or a surgical stent and template for auricular rehabilitation. The research compares two digital ear impression techniques using an Intra-Oral digital Scanner (IOS) (with /without markers) versus a traditional technique using hydrocolloid impression materials. MATERIAL AND METHODS: Eight participants were selected with intact right ears. Patients' right ears were digitally scanned with an IOS, once with resin markers and once without markers. A conventional auricular impression was taken for each participant, which was then scanned using a desktop scanner. The digital IOS technique with markers was set as a reference model. Total 3D deviations between the study groups were calculated using Geomagic control software (software for 3D coordinate measuring technology). An independent sample t-test was used to make comparisons between the two tested groups. RESULTS: The conventional impression and the intraoral scan without markers recorded a mean of 1.4057 ± 0.3581 and 0.7605±0.1469, respectively, of total 3D deviation from the intraoral scan with markers. There was a significant difference in auricular impression accuracy between conventional and intraoral scans without markers. CONCLUSIONS: Using intraoral scanners facilitates impression acquisition and increases the accuracy compared to traditional hydrocolloid impression techniques, which may affect the shape of tissue due to its liability to be compressed by the impression material. Using markers allows for very precise data collection, reducing stitching complications that affect the accuracy of scans taken without markers. CLINICAL SIGNIFICANCE: The proposed technique for auricular digital impression using an intraoral scanner guarantees a fast technique with accurate results in acquiring anatomical data for the rehabilitation of ear defects. This research was registered on clinicaltrials.gov with the following registration number: NCT04893902.

Recording jaw relation of a pediatric patient with ectodermal dysplasia and complete anodontia using a digital mini arch tracer: A case report.

Children with ectodermal dysplasia and complete anodontia experience difficulties in oral rehabilitation because of the small arch size. A case of a 7-year-old boy, whose arch size (length and width) was 30-40% smaller than that of a male adult and who presented with difficulties in jaw relation recording using commercially available devices is described. A digital workflow involving a mini arch tracer was introduced. Primary impressions were made using three-dimensionally (3D) printed mini trays produced based on the patient's computed tomography images, and digital primary casts were obtained based on the scanned and reversed primary impressions. The final custom impression trays with mini tracing plates were designed based on the primary casts. In addition, the hand shank, retention plate, and retainers were placed on the designed custom trays and 3D-printed to produce an individual arch tracer system. In addition, two height-checking buckles were designed to help adjust the height of a tracing screw. Finally, the jaw relation of the patient was recorded and transferred, and a set of complete dentures were delivered, satisfying both the patient and his family.

The biotransfer approach: The use of an alveolar cast die for the fabrication of the emergence profile on implant-supported interim restorations.

Maintaining natural-looking soft tissues around dental implants is one of the biggest challenges for the restorative team. To achieve this, the emergence profile of the preexisting teeth in the alveolus can be emulated rather than conditioning the soft tissue architecture arbitrarily. The biotransfer technique uses an interim restoration with a biologically driven emergence profile fabricated before the implant surgery.

Digital Impression Taking for Maxillary Full-Arch Restoration With Immediate Loading: A Case Report.

The aim of this clinical report is to describe a maxillary full-arch implant supported restoration with immediate loading performed by means of an entirely digital work flow with photogrammetric system and intraoral scanning. A female patient with an edentulous maxillary arch attended the dental clinic seeking a maxillary fixed restoration. After treatment planning, 6 implants were placed using a surgical splint fabricated digitally by intraoral scanning of her previous removable prosthesis. Multiunit abutments were fitted, and 2 digital impressions were taken, one with a photogrammetric system for determining implant positions and the other with an intraoral scanner for soft tissue registration. The acrylic resin structure of the immediate prosthesis was milled and placed within 8 hours of implant surgery. This provisional structure fitted correctly and provided adequate esthetics and function. Radiographic and clinical follow-up after 24 months observed adequate implant evolution.

Accuracy of capturing nasal, orbital, and auricular defects with extra- and intraoral optical scanners and smartphone: An in vitro study.

OBJECTIVES: This in vitro study compares the scanning accuracy of various stationary and portable as well as extra- and intraoral devices for capturing oncological defects. METHODS: A 3D-printed model of a nasal, orbital, and auricular defect, as well as one of an intact auricle, were digitalized (n = 7 per device) with a stationary optical scanner (Pritiface), a portable extraoral optical scanner (Artec Space Spider), two intraoral scanners (Trios 4 and Primescan), and a smartphone (iPhone 11 Pro). For the reference data, the defect models were digitalized using a laboratory scanner (D2000). For quantitative analysis, the root mean square error value for trueness and precision and mean deviations in millimeters were obtained for each defect type. The data were statistically analyzed using two-way ANOVA and Tukey multiple comparison test. For qualitative analysis, a colorimetric map was generated to display the deviation within the defect area and adjacent tissue. RESULTS: Statistically significant interactions were found in the trueness and precision for defect and scanner type. CONCLUSION: The Primescan and Artec Space Spider scanners showed the highest accuracy for most defect types. Primescan and Trios 4 failed to capture the orbital defect. The iPhone 11 Pro showed clinically acceptable trueness but inferior precision. CLINICAL SIGNIFICANCE: The scanning devices may demonstrate varying accuracy, depending on the defect type. A portable extraoral optical scanner is an universal tool for the digitization of oncological defects. Alternatively, an intraoral scanner may be employed in maxillofacial prosthetics with some restrictions. Utilizing a smartphone in maxillofacial rehabilitation should be considered with caution, because it provides inconsistent accuracy.

Forma del arco dentario en estudiantes de Medicina / Shape of the dental arch in medicine students

Introducción: Por varios siglos ha sido estudiada la forma y el tamaño de la arcada dental del ser humano. Los huesos de la mandíbula y el maxilar, la posición de los dientes, la musculatura perioral y las fuerzas funcionales intraorales determinan la forma del arco dental. Objetivo: Describir la forma de los arcos dentarios de los estudiantes de la carrera de Medicina de la Universidad Nacional de Chimborazo, durante el periodo abril-agosto de 2019. Métodos: Estudio descriptivo, transversal y cuantitativo. La muestra quedó conformada por 60 estudiantes de ambos sexos. Se realizó, en alginato y vaciados en yeso extraduro, la toma de impresiones del maxilar y la mandíbula, para identificar el tipo de arco dentario según la tabla determinada por Chuck. Resultados: En el maxilar predominó la forma cuadrara (48,30 por ciento); seguida de la ovoide (38,30 por ciento) y, por último, la estrecha (13,30 por ciento). En la mandíbula la forma predominante fue la estrecha (36,70 por ciento). Conclusiones: La mayoría de los arcos dentarios en el maxilar fueron de forma cuadrada, mientras que en el arco mandibular fueron de forma estrecha(AU)

Introduction: In humans, the shape and size of the dental arc has been studied for several centuries. The bones of the jaw and maxilla, the position of the teeth, the perioral musculature and the intraoral functional forces determine the shape of the dental arch. Objective: To determine the shape of the dental arcs in students of the School of Medicine of Universidad Nacional de Chimborazo during the period April-August 2019. Methods: A descriptive, cross-sectional and quantitative study is presented; with a universe of 320 students and the sample was formed by 60 of both sexes (female and male), who signed the informed consent. Maxillary and jaw impressions were taken using alginate and made with extra hard Dental Stone in order to identify the type of dental arc according to the table determined by Chuck. Results: In the maxilla, the square shape was observed in 48.30 percent; continue the ovoid with 38.30 percent and narrow with 13.30 percent. In the jaw the narrow shape (36.70 percent), the ovoid (35.00 percent) and the square (28.30 percent). Conclusions: Most of the dental arcs in the maxilla are square; as well as in the mandibular arc the narrow shape. In both cases, the ovoid form continued(AU)

Patient's perception of intraoral scanning: a comparison between traditional and digital dental impression.

The purpose of this work was to assess the discomfort perceived by the patient during the intraoral scan procedure using the iTero Scanner. A sample of 33 patients was selected on the basis of parameters that identify a complete dentition. All treated patients underwent a traditional polyvinylsiloxane impression with double procedure and an intraoral scan in the same session. Subsequently they were given a questionnaire concerning the discomfort perceived by both procedures. Once the completed questionnaires were obtained, preliminary statistical tests were carried out to check if the distribution of scores assigned by patients to the two procedures differed significantly from a Gaussian distribution. Furthermore, the discomfort/preference indexes for the two procedures were compared using the Wilcoxon test for paired data. Finally, the Spearman correlation test was used. From the results of the preliminary normality tests, it was decided to use nonparametric type tests that gives the intraoral scan procedure more favorable scores relative to a minor discomfort. The use of intraoral scanning and more specifically of the iTero 2.9 scanner (despite a not small wand), represents an option largely preferred by patients in terms of reduction of discomfort and classic discomfort related to relief systems traditional imprint.

Traditional versus simplified impression methods for complete dentures: critical appraisal of evidence / Método tradicional versus simplificado en impresiones para prótesis total removible: evaluación crítica de la evidencia Método tradicional versus simplificado

Abstract Introduction: Inspite of the great advances in dentistry, aging populations imply that there are still significant numbers of edentulous people worldwide. In most cases, implant-assisted prosthetic rehabilitation is the best solution. However, economic issues constrain access to this therapeutic approach, meaning that conventional removable prosthetics continue to be the most frequent treatment. In the removable denture making process, the so-called traditional method has been widely taught and used. It involves taking two impressions: a preliminary one followed by a definitive one (or functional). The simplified method constructs the prosthesis directly from the first impression obtained with a stock tray, without the need of a second impression. Purpose: To review the scientific evidence comparing both methods in terms of patient satisfaction, clinical quality, and masticatory performance and capacity. Results: No advantages have been found in favor of the traditional method regarding the four variables selected. Conclusions: According to the available information, the traditional method of taking impressions for complete removable dental prostheses does not provide significantly superior clinical results when compared to those obtained using the simplified method in terms of clinical quality, patient satisfaction, performance and masticatory capacity.

Resumen Introducción: Pese a los avances de la odontología, el fenómeno del envejecimiento de la población ha generado que la cantidad de personas desdentadas totales aún represente una cifra significativa. Los artificios protésicos implanto-asistidos constituyen, en la mayoría de los casos, la mejor alternativa rehabilitadora. Sin embargo, la variable económica surge como el principal impedimento para que los pacientes accedan a este recurso, y por este motivo, mantienen la prótesis total removible como una opción terapéutica. Para su confección, el método tradicional indica la necesidad de tomar dos impresiones: una preliminar y una definitiva o funcional. El método simplificado, confecciona la prótesis a partir de la primera impresión, obtenida con cubeta de stock. Objetivo: Revisar evidencia científica que compara ambos métodos en cuanto a las variables de: satisfacción del paciente, calidad clínica, rendimiento y capacidad masticatoria. Resultados: No se verifican ventajas a favor del método tradicional en relación a las variables estudiadas. Conclusiones: En concordancia con la información recabada, los resultados clínicos obtenidos mediante el método tradicional de toma de impresiones para prótesis totales no son significativamente superiores a los del método simplificado en relación a calidad clínica, satisfacción del paciente, rendimiento y capacidad masticatoria.

Eficacia del cementado indirecto / Indirect bonding efficiency

La aparición de aparatología preadjustada ha colaborado en la efectividad de los tratamientos de ortodoncia, pero para que la expresión de esta aparatología se logre, es necesario una correcta colocación de los brackets y la permanencia de estos en boca durante todo el tratamiento. La precisión en la colocación mejora con la técnica de cementado indirecta, ya que permite el acceso a las zonas posteriores, a lugares donde se ve disminuida la visión y además disminuye la condensación de aliento y contaminación salival. Si bien esta técnica requiere tiempo extra de laboratorio, es más rápida en la etapa clínica (AU)

Precisión de los sistemas de impresión digital intraoral en odontología restauradora: Una revisión de la literatura / Accuracy of Intraoral Digital Impression Systems in Restorative Dentistry: A Review of the Literature

Abstract: La impresión intraoral permite al odontólogo obtener directamente los datos de las piezas dentales que se requiera rehabilitar, otorgándole mayor precisión y eliminando así de la fase clínica la toma de impresión y la fabricación del modelo, aspectos sensibles a errores. El objetivo de la presente revisión es identificar el sistema de impresión digital intraoral más preciso y además identificar los factores que afectan a la precisión de esta en odontología restauradora. Mediante una revisión bibliográfica con búsqueda en las bases de datos de PubMed y Embase se obtuvieron 153 artículos, luego de la evaluación cualitativa se incluyeron en la revisión 14 que cumplieron con los criterios de inclusión y exclusión. Se determinó que la experiencia del dentista, la convergencia en la preparación dental y la terminación cervical son determinantes al momento de la toma de impresión digital, sin embargo, el uso o no de polvo no es relevante. El sistema de impresión digital Lava C.O.S., iTero y True definition son los más precisos dependiendo siempre del tipo de rehabilitación a realizar.

Abstract: Digital impresión allows the dentist to directly obtain the data of the dental pieces that neet to be rehabilitated, giving it greater precisión and thus eliminating the impression and manufacturing of the dental model, error-sensitive aspects of the clinical phase. The aim of this review is to identify the most accurate intraoral digital impression system and identifiy the factors that affect the accuracy in the restorative dentistry. Through a bibliographic review with search in PubMed and Embase databases, 153 articles were obtained, after qualitative evaluation they were included in the revisión 14 that met the inclusion and exclusion criteria. It was determined that the experience of the dentist, the convergence in the dental preparation and the cervical termination are decisive at the accuracy of the digital impression, however, the use or not of dust is not relevant. The Lava C.O.S., iTero and True definition are the most accurate always depending on the type of rehabilitation to be performed.