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)

Alternative Dose Of Four Alginates To Minimize Risks During The Impression Technique Of The Upper Maxillary.

For the impression or mouth records there are different biomaterials, one of them, is the irreversible Hydrocolloid called Alginate, It is a gelling agent and viscocifier that allows to reproduce in detail the hard and soft tissue structures of the oral cavity. Alginate is commercially available in powder form, formed of alginic acid, which comes from marine algae; calcium sulfate, trisodium phosphate and diatomaceous earth; that when mixed with water, they form a colloidal sun (plastic mass). When in contact with the patient's mouth, begins the gelling process and ends in 7 minutes, in this way the exact reproduction of the dental arches is obtained. Finally, the emptying with plaster is performed, to obtain the duplication of the maxillary.

Research progress of orthodontic indirect bonding technology / 口腔疾病防治

@#Accurate positioning of brackets is a necessary condition for ideal orthodontic treatment. Traditional bracket bonding technology has certain limitations, such as long operation time and poor accuracy. Indirect bonding technology is a method that bonding brackets on the model through intraoral impression or scanning, and then the brackets are accurately bonded to the tooth crowns using a transfer tray. In this article, the progression of transfer trays and adhesive agents, the application of digital technology in indirect bonding technology, indirect bonding for invisible appliances, and the prospect of this technology are reviewed. The literature review results show that indirect bonding technology can locate the bracket accurately, the operation is simple, the patient’s experience is comfortable, and the clinical efficiency can be significantly improved, the photocurable adhesive is an ideal adhesive for indirect bonding technology. With the development of digital technology, indirect bonding technology will be able to locate the brackets with increasing accuracy, thus achieving the "digital precision movement" of the teeth. The bonding technology of invisible appliance accessories is essentially a type of indirect bonding technology, It requires indirect bonding technology and digital technology to highly fit the needs of computer design accessories for the visual tooth movement and the use of indirect bonding technology to accurately bond accessories, ultimately achieving the desired tooth movement. Indirect bonding technology will play an increasingly important role with the development of digital technology and invisible correction technology.

Accuracy of new implant impression technique using dual arch tray and bite impression coping

PURPOSE: The purpose of this in vitro study was to evaluate the accuracy of a new implant impression technique using bite impression coping and a dual arch tray. MATERIALS AND METHODS: Two implant fixtures were placed on maxillary left second premolar and first molar area in dentoform model. The model with two fixtures was used as the reference. The impression was divided into 2 groups, n=10 each. In group 1, heavy/light body silicone impression was made with pick up impression copings and open tray. In group 2, putty/light body silicone impression was made with bite impression copings and dual arch tray. The reference model and the master casts with implant scan bodies were scanned by a laboratory scanner. Surface tessellation language (STL) datasets from test groups was superimposed with STL dataset of reference model using inspection software. The three-dimensional deviation between the reference model and impression models was calculated and illustrated as a color-map. Data was analyzed by independent samples T-test of variance at α=.05. RESULTS: The mean 3D implant deviations of pick up impression group (group 1) and dual arch impression group (group 2) were 0.029 mm and 0.034 mm, respectively. The difference in 3D deviations between groups 1 and 2 was not statistically significant (P=.075). CONCLUSION: Within limitations of this study, the accuracy of implant impression using a bite impression coping and dual arch tray is comparable to that of conventional pick-up impression.

Study on the consistency of the position of the brackets on the digital occlusal model and the actual position af-ter indirect bonding / 口腔疾病防治

Objective@#To provide the experimental basis for the coherence of the indirect bond position by comparing the position of the bracket on the digital occlusal model and the position of the transfer to the initial plaster model.@*Methods@#Fifteen digitized models were selected for the brackets on the dental denture model, the brackets were transferred to the initial plaster model by indirect bond transfer trays, The line distance between each bracket position in digital dental model and initial plaster model was measured with OrthoRx software. @*Results @#The difference between the position of the orthodontic brackets and the position of the initial plaster model was less than 0.20 mm, and the difference was statistically significant (P < 0.05). @*Conclusion @#The position of the bracket on the digital occlusal model is consistent with that of the original plaster model, which provides a theoretical basis for digital indirect bonding.

Application of self-made guided wire operating-tray in performing percutaneous coronary intervention / 介入放射学杂志

Objective To explore the application of self-made guided wire operating-tray,which is designed for percutaneous tranluminal coronary angioplasty (PTCA),in performing coronary intervention (PCI).Methods A total of 40 patients who were planned to receive PCI were randomly divided into the study group (n=20,using guided wire operating-tray) and the control group (n=20,using traditional method to operate guide wire).Under local anesthesia PCI was carried out in all patients of both groups.The frequency of guide wire winding,the degree of surgical sheet contamination within the operation area,and the comfort and convenience of operating guide wire were assessed,the results were compared between the two groups.Results The frequency of guide wire winding and the degree of surgical sheet contamination within operation area in the study group were remarkably lower than those in the control group (P＜0.05).The comfort and convenience of operating guide wire in the study group was better than that in the control group (P＜0.05).Conclusion In performing PCI,the use of self-made guided wire operating-tray can effectively avoid guide wire winding and reduce the degree of surgical sheet contamination within the operation area.

Implant impression using closed mouth impression technique: a case report

Closed mouth impression technique by using bite tray is preferred for single tooth impression taking. However, for implant impression taking, open mouth impression technique by using single arch tray is generally used whether it is for single implant or multiple implant. Closed mouth impression technique by using bite tray can save time and materials. It also decreases the chance of error occurrence when a model is mounted on an articulator. In this case report, we tried to show a satisfying result of fabricating single implant fixed prosthodontics after bite tray impression taking by using two different copings for closed mouth impression.

An alternative impression technique based on McLean's functional impression concept / 대한치과보철학회지

In this case report, an alternative impression technique for fabricating removable partial dentures was used in a patient with very few remaining teeth. In this technique, an individual tray was made on the cast, which was made by relining interim denture and taking overimpression with irreversible hydrocolloid according to McLean's functional impression concept. This method showed the following advantages: the no need for border molding with modeling compound, time saving for denture impression without overextension and accurate seating of the individual tray.

Accuracy of a separating foil impression using a novel polyolefin foil compared to a custom tray and a stock tray technique

PURPOSE: To compare the dimensional accuracy of three impression techniques- a separating foil impression, a custom tray impression, and a stock tray impression. MATERIALS AND METHODS: A machined mandibular complete-arch metal model with special modifications served as a master cast. Three different impression techniques (n = 6 in each group) were performed with addition-cured silicon materials: i) putty-wash technique with a prefabricated metal tray (MET) using putty and regular body, ii) single-phase impression with custom tray (CUS) using regular body material, and iii) two-stage technique with stock metal tray (SEP) using putty with a separating foil and regular body material. All impressions were poured with epoxy resin. Six different distances (four intra-abutment and two inter-abutment distances) were gauged on the metal master model and on the casts with a microscope in combination with calibrated measuring software. The differences of the evaluated distances between the reference and the three test groups were calculated and expressed as mean (± SD). Additionally, the 95% confidence intervals were calculated and significant differences between the experimental groups were assumed when confidence intervals did not overlap. RESULTS: Dimensional changes compared to reference values varied between -74.01 and 32.57 µm (MET), -78.86 and 30.84 (CUS), and between -92.20 and 30.98 (SEP). For the intra-abutment distances, no significant differences among the experimental groups were detected. CUS showed a significantly higher dimensional accuracy for the inter-abutment distances with -0.02 and -0.08 percentage deviation compared to MET and SEP. CONCLUSION: The separation foil technique is a simple alternative to the custom tray technique for single tooth restorations, while limitations may exist for extended restorations with multiple abutment teeth.

A Simple Method to Check the Border Extensions of Custom Tray.

Proper extensions of custom trays are of supreme importance during border molding and final impression making. This article describes a novel method to evaluate the peripheral extensions of custom trays prior to border molding.

In‑office technique to fabricate triple tray.

Dual arch impressions have been in use for many years. Five in‑office techniques for fabrication of the tray have been suggested, in case the manufactured (stock) tray is not available to the clinician. The design consists of two parts of the tray (the plastic frame and lattice). Five types of materials for the lattice have been described. The indications, advantages, and disadvantages of the techniques together with an appraisal of the five different lattice materials have been described. Overall the techniques are simple and require materials that are easily available. It does not take much time and can be used to attain efficient results in case the stock tray is not available in the operatory.

A comparative evaluation of linear dimensional accuracy of the dies obtained using three conceptually different die systems in the fabrication of implant prosthesis: An in vitro study.

Statement of Problem: Given that meticulous implant prosthodontic procedures are recommended to obtain the best possible intraoral fit, the die systems used for multi implant casts warrant further investigation. Die stone expansion and errors introduced by removable die casts may exceed the accuracy required for the passive fit of implant prosthesis. Purpose: The purpose of the study was to evaluate the linear dimensional accuracy between the implant master die and three conceptually different die systems such as Pindex system, Accu-trac precision die system, and Conventional brass dowel pin system. Materials and Methods: Thirty impressions of implant master die were made with polyether impression material. Ten experimental implant casts were fabricated for each of the three different die systems tested: Accu-trac precision die tray system, Pindex system, and conventional brass dowel pin system. The solid experimental casts were sectioned and then removed from the die system 30 times. Linear distances between all six possible distances were measured from one centre of the transfer coping to the other, using a co-ordinate measuring machine in millimeters up to accuracy of 0.5 microns. Data were tabulated and statistically analyzed by Binomial non parametric test using SPSS version 15. Results: Significant differences were found for distance A-B (P = 0.002), A-C ( P = 0.002), A-D (P value = 0.002), and B-D ( P = 0.021) in Conventional Dowel pin system however for Accu-trac precision die tray system, it was significant only for distance A-D (P = 0.002) but for Pindex system it was non-significant for all the distances measured. Conclusion: Within the limitations of this study, use of Pindex system is recommended when sectioned dies are needed for a multi implant retained prosthesis.

A comparative evaluation of tray spacer thickness and repeat pour on the accuracy of monophasic polyvinyl siloxane impression material: In vitro study.

Purpose: This study was aimed to determine the effect of various tray spacer thickness and subsequent repeated pours on the accuracy and dimensional stability of the impression made from monophasic polyvinyl siloxane material. Materials and Methods: Custom trays with different spacer thickness (2, 4 and 6 mm) were used for making an impression of a master model simulating 3 unit fixed partial denture with monophasic polyvinyl siloxane material. These impressions were poured with die stone and repoured. Distance between the reference points were measured and subjected to statistical analysis. Result: Casts obtained from 1 st , 2 nd and 3 rd pour of the impression in 2, 4 and 6 mm spacer thickness tray have similar dimensional accuracy amongst each other and with the master model except in molar diameter and inter-abutment distances of cast obtained from 6 mm spacer thickness tray. Conclusion: The vertical distance of stone dies were decreased, whereas horizontal distance increased as the thickness of impression material is increased. There were statistically non-significant changes occurring among the repeated pours in 2, 4 and 6 mm spacer thickness. Clinical Implication: 2 and 4 mm spacer thickness are acceptable for making an impression for three unit fixed partial denture with monophasic polyvinyl siloxane material and it was not affected by two subsequent (1 st and 2 nd ) repeated pours.

Análisis numérico sobre esfuerzos y áreas de contacto en una PTR Scorpio II® Stryker®. Base para el diseño de PTR personalizada al fenotipo Mexicano / Numerical analysis on stresses and contact areas in a TKR Scorpio II® of Stryker®. Basis to design of customized TKR in accordance to Mexican Phenotype

El desgaste de los insertos de Polietileno de Ultra-Alto Peso Molecular (UHMWPE pos sus siglas en inglés) continúa afectando la longevidad de las prótesis totales de rodilla (PTR) junto con el aflojamiento aséptico, y ambos constituyen las dos principales causas de falla de las prótesis. Considerando esto, es necesario encontrar soluciones adecuadas para evitar el desgaste excesivo y hasta la ruptura de los insertos de polietileno. En este trabajo se realizó el estudio mediante simulación numérica de una PTR Scorpio II® Stryker®, la cual se retiró por desgaste del inserto de UHMWPE en el Hospital 1° de Octubre del ISSSTE en México. Se utilizaron las hipótesis de Bartel et al. (1995) y Chillag et al. (1991) para la validación del método numérico utilizado, las cuales establecen que el desgaste del polietileno puede reducirse utilizando insertos tibiales de mayor espesor, lo cual disminuye las presiones de contacto. Los análisis se realizaron mediante MEF variando el espesor del inserto de 6, 8, 10, 12 y 14 mm, suponiendo cargas axiales de tipo cuasi-estático en la articulación a cero grados de flexión, para 1.33 veces el peso de un individuo de 75 kg (736 N) empleando el ciclo normalizado de marcha. Los resultados obtenidos muestran similitud con los reportados por Bei et al. (2004) y Deen et al. (2006). Después de validar el método, se desarrolló el modelo de MEF de la PTR y se determinaron las curvas de esfuerzo y de áreas de contacto del inserto de UHMWPE, con lo que se obtuvo información importante para modificar el diseño y obtener una prótesis de geometría conforme en los planos coronal y sagital del inserto femoral y el inserto de polietileno, de acuerdo con el fenotipo mexicano.

Wear of UHMWPE inserts continues affecting the longevity of total knee replacements (TKR) together with septic loosening, and both constitute two main causes of prosthesis failure. It is necessary to find appropriate solutions to avoid excessive wear and failure of polyethylene inserts. In this work a study was carried out by means of numeric simulation of a Scorpio II® Stryker® TKR, which was retired due to wear of UHMWPE in the Hospital 1° de Octubre of ISSSTE in Mexico city. Hypotheses of Bartel et al. (1995) and Chillag et al. (1991) were used, which settle down that wear of polyethylene can decrease using thicker tibial inserts, which can be reduced contact pressures. Analyses of this work was carried out by means of FEM varying insert thickness of 6, 8, 10, 12 and 14 mm, considered quasi-static axial loads actuating on the articulation with zero degrees of flexion and loads equivalent to 1.33 times of bodyweight of a subject of 75 kg (736 N) was considered. Normalized gait cycle was employed and results obtained are similar to those reported by Bei et al. (2004) and Deen et al. (2006). After validating the method, a model of study case of TKR in FEM was developed and the curves of stress and contact areas of UHMWPE were determined, with which important information was obtained to modify the design, as well as to obtain a prosthesis of optimal conformity in both coronal and sagital planes of the femoral and UHMWPE inserts, in agreement with characteristics of the Mexican phenotype.

Single step approach to make diagnostic impressions of both the arches and face bow transfer: A novel technique.

Context: Mounting the maxillary and mandibular dentulous casts for Diagnostic purpose requires many steps (including making maxillary and mandibular impressions, face-bow transfer, and bite registration) or many appointments. A simple new technique of doing all of this together without compromising on the accuracy can save time over the conventional mounting procedure. Aim: To compare the accuracy of a new technique of a single-step diagnostic mounting procedure with that of the conventional diagnostic mounting procedure. Materials and Methods: Ten dentulous patients with the full complement of teeth and without any history of temporomandibular disorder and orthodontic treatment were selected for this study. A detachable metal triple tray to replace the fork part of the face bow fork that further could be attached to face bow was fabricated. Dual-arch impressions and face-bow transfer were made in these subjects using this modified triple tray. These mountings were compared with the ones done with the conventional mounting procedure. Five linear measurements (using stable reference points on the articulator and the cast) were made and the values obtained by both the methods were compared. Statistical Analysis: The Student's 't' test for statistical analysis was used in this study. Results: The measurement values obtained by the single-step method were almost similar to the ones obtained by the conventional method. The various mean measurements for the single step and conventional methods were 37.7 ± 6.8 and 38.5 ± 6.5 mm; 70.0 ± 4.4 and 70.1 ± 4.2 mm; 57.0 ± 4.9 and 57.3 ± 4.2 mm; 71.3 ± 4.5 and 71.0 ± 4.6 mm; and 58.7 ± 2.5 and 58.3 ± 2.3 mm; respectively. The differences between the values obtained by the conventional and single-step methods were not statistically significant. Conclusion: The single-step procedure of diagnostic mounting can be used as an alternative to the conventional method, without compromising the quality of mounting.

Prosthodontic Rehabilitation Of Mandibular Resorbed Ridge: A Different Approach.

The treatment of edentulous patient is always a challenge for the Prosthodontist. It is connected with a lot of procedures aiming to reconstruct and replace the mandible and maxilla for the patients who have lost all their remaining teeth. Treating the highly resorbed mandibular ridge accompanied with an enlarged tongue, along with the average response of the patient to all the clinical procedures, is a tedious job. The aim of this article is the prosthetic treatment of a mentally challenged patient with asymmetry of alveolar ridges, macroglossia and the difficulties related with the treatment and the suitable techniques and approaches to overcome those difficulties.

Protocolo protésico - quirúrgico en temporización inmediata de dientes unitarios, utilizando una cubeta multifuncional desmontable / Prosthetic protocol - surgery in the immediate temporization of a single tooth using a multifunctional removable tray

Propósito: El presente reporte clínico es la descripción de un protocolo protésico - quirúrgico que permite la visualización directa del sitio operatorio y el correcto posicionamiento protésico - implantario de una corona temporal atornillada, construida inmediatamente de insertado el implante. Material y métodos: Se seleccionaron 10 pacientes del programa de especialización en implantologia bucomaxilofacial de la Universidad de Chile, cuyo criterio de inclusión principal fue ser desdentado parcial unitario posterior, con antagonista dentario natural. Como protocolo diagnóstico se solicitaron exámenes de laboratorio, exámenes radiograficos y se registraron sus arcos dentarios con impresiones de estudio a fin de obtener modelos de yeso, los que fueron posicionados en un articulador semiajustable tipo Whip Mix, donde se confeccionó un encerado diagnóstico del diente a reemplazar, libre de contacto oclusal en máxima intercuspidación (MIC) y en los movimientos excursivos mandibulares. Basado en el encerado de diagnóstico se diseño una cubeta multifuncional desmontable (U. de Chile) cuya característica fundamental es que fusiona una guía quirúrgica y una guía de montaje protésico, para una correcta temporización inmediata. El procedimiento se inicia mediante un colgajo de espesor total, posicionamiento en boca de la guía multifuncional en fase quirúrgica, para permitir el fresado del lecho implantario y la inserción implantaria. El lecho quirúrgico es suturado mediante una seda negra trensada y se confecciona en forma inmediata una corona temporal atornillada utilizando la guía multifuncional en fase de carga protésica. Resultados: Se instalaron un total de 12 implantes Renova Tapered (Lifecore) utilizando la cubeta multifuncional la cual facilitó la direción del fresado y la contrucción de sus respectivas coronas temporales de resina acrilica, no segmentadas atornilladas. Conclusiones: Con las limitaciones de este estudio, la fusión de ambos procedimientos brinda...

Purpose: This clinical report is the description of a prosthetic protocol - surgery which allows direct visualization of the operative site and the correct positioning of the prosthetic-implantation of a screw retained temporary crown constructed immediately following the insertion of the implant. Methods: 10 patients, whose main inclusion criterion was having a partially edentulous posterior unit with an opposing natural tooth, were selected from the specialized program of Maxillofacial Implantology at the University of Chile. As diagnostic protocol was requested, laboratory tests, radiographic examinations and impressions of dental arches were recorded in order to obtain plaster models for the study and which were positioned in a semi-adjustable articulator type Whip Mix, which produced a diagnostic wax-up tooth replacement, free of occlusal contact in the maximal intercuspal (MIC) and mandibular excursions. Based on the diagnostic wax-up one can design a multi-functional removable tray (U. de Chile), whose key feature is that it merges a surgical guide and a prosthetic assembly guide for the correct immediate temporization. The procedure starts with a full thickness flap positioned in the mouth of the multi-functional guide of the surgical phase to allow the implant site drilling and implant insertion. The surgical site is sutured with black braided silk and you immediately draw up the screw retained temporary crown using the multi-functional guide in the prosthetic loading phase. Results: A total of 12 Renova Tapered implants (Lifecore) were installed using the multi-functional tray which provided the direction of the drilling and construction of its acrylic- resin temporary crowns without segmented screws. Conclusions: With the limitations of this study, the merging of both procedures provide a predictable safe alternative treatment that is quick and easy to implement for the clinician allowing the immediate temporization of the implant. Technical Report.

Alternative impression technique for multiple abutments in difficult case to control

BACKGROUND: Even though excellent impression materials are now available for making accurate replication for hard and soft tissue, the numerous dentists have faced lots of obstacles in making simultaneous impressions of multiple abutments. CASE DESCRIPTION: This article describes a modified method of tray fabrication using auto-polymerizing acrylic resin and impression technique for multiple prepared teeth in cases with limitations and difficulties in taking dental impressions. CLINICAL IMPLICATION: This segmental tray technique has several advantages, including higher impression quality, fewer impressions, and being more comfortable for the patient and less stressful for the clinician.

A comparative study of inter-abutment distance of dies made from full arch dual-arch impression trays with those made from full arch stock trays: An in vitro study.

Objectives: The dual-arch impression technique is convenient in that it makes the required maxillary and mandibular impressions, as well as the inter-occlusal record in one procedure. The accuracy of inter-abutment distance in dies fabricated from dual-arch impression technique remains in question because there is little information available in the literature. Materials and Methods: This study was conducted to evaluate the accuracy of inter-abutment distance in dies obtained from full arch dual-arch trays with those obtained from full arch stock metal trays. Results and Conclusion: The metal dual-arch trays showed better accuracy followed by the plastic dual-arch and stock dentulous trays, respectively, though statistically insignificant. The pouring sequence did not have any effect on the inter-abutment distance statistically, though pouring the non-working side of the dual-arch impression first showed better accuracy.

Study in application of ultraviolet disinfectant equipment with intense light board in the disinfection of moulage tray and reformative model / 中国实用护理杂志

Objective To find a safe way to disinfect moulage tray and reformative model for the department of stomatology and refine the traditional disinfection method. Methods Using the self-developed ultraviolet disinfectant equipment with intense light board, by virus and HBsAg contamina-tion test, we compared the numbers of virus in the observation group and the control group, which con-sisted of 122 moulage trays and reformative models, before and after disinfection, and observed the ef-fect of disinfection. Results After 5-minute disinfection, 99.99% living bacteria were killed, which meets the standard requirement of P.R.C health department that indicator bacteria killing ratio must be greater or equal than 99.9%. After 18-minute disinfection, HBsAg antigen destructiveness meets S/N< 2.1 standard of P.R.C health department. After 20 min, the antigen was destroyed completely. Bacteria contents before and after disinfection in 122 moulage trays and reformative models were different in statistics.. Conclusions The disinfection method using ultraviolet disinfectant equipment with intense light board is harmless, taintless and efficient, and provides a safe, reliable and maneuverable way for the moulage tray and reformative model disinfection in the department of stomntology.