Research progress on the design of fixed implant-supported prostheses in edentulous jaws / 口腔疾病防治

@#With the aging of the population and the increase in the number of edentulous patients, implant-supported fixed restorations have become more prevalent in clinical treatment. It is necessary to assess the patient's remaining bone and occlusal situation correctly; the upper jaw usually needs 6 to 8 implants, whereas the lower jaw needs 4 to 6 implants. Patients with severe alveolar bone atrophy can adopt the "all-on-4/6" treatment plan, short implants, and zygomatic and pterygomaxillary implants to avoid complex bone grafting and remain cautious when the surgical procedures require more surgical experience. According to the repair methods, the superstructure can be divided into one-piece repair and segmental repair. One-piece repair has a lower implant number, flexible location, and reasonable stress distribution but a high maintenance cost. Sectional repair easily achieves passive placement, convenient cleaning, and maintenance in the late stages, but implants need quantity and high requirements for alveolar bone. However, the requirements for alveolar bone and implant number are high. Mutually protected occlusion with minimal or no cantilever on provisional prosthesis is recommended.

Accuracy of Intraoral Scanners and Conventional pressions in Full-Arches: A Systematic Review

ABSTRACT: The aim of this study was to evaluate intraoral scanners accuracy in full-arches, comparing them with conventional impressions. A scientific research performed in MEDLINE, EBSCOhost, and SciELO databases was conducted to analyze articles published between 2015 and 2020. Clinical and in vitro studies that evaluated accuracy (precision and trueness) from intraoral scanners and conventional impressions in full-arches were included. Two tests were applied to evaluate the methodological bias from the studies. Out of the 191 articles found, seven of them were selected for a qualitative analysis. In clinical studies,intraoral scanners CEREC Omnicam and 3Shape TRIOS Colorhad the highest precision compared to conventional irreversible hydrocolloid impressions. In in vitro studies, conventional polyvinyl siloxane impressions showed the highest accuracy, followed by intraoral scanners Cadent iTero and CEREC Omnicam, while irreversible hydrocolloid impressions showed the lowest accuracy. Digital intraoral impression systems do not show superior accuracycompared to highly accurate conventional impression techniques. However, they provide excellent clinical results and both methods are clinically accepted.

RESUMEN: El objetivo de este estudio fue evaluar la exactitud de escáneres intraorales en impresiones digitales de arco completo en comparación con las impresiones convencionales. Se realizó una revisión sistemática en las bases de datos MEDLINE, EBSCOhost y SciELO para analizar artículos publicados entre los años 2015 y 2020. Se incluyeron estudios clínicos e in vitro que evaluaran exactitud (precisión y/o veracidad) de escáneres intraorales impresiones convencionales en arcos completos. Dos pautas se aplicaron para evaluar el riesgo de sesgo de los estudios. De 191 artículos encontrados, 7 fueron seleccionados para un análisis cualitativo. En los estudios clínicos, los escáneres intraorales CEREC Omnicam y 3Shape TRIOS Color presentaron la mayor precisiónen comparación con las impresiones convencionales de hidrocoloide irreversible. En los estudios in vitro, las impresiones de polivinil siloxano presentaron la mayor exactitud seguido por los escáneres intraorales CadentiTero y CEREC Omnicam, mientras quelas impresiones de hidrocoloide irreversible presentaron la menor exactitud. Los sistemas de impresión digital intraoral no mostraron tener una exactitud superior comparados con las técnicas de impresión convencional de gran exactitud. Sin embargo, proveen excelentes resultados clínicos y ambos métodos son clínicamente aceptables.

Effect of accelerated aging on long-term accuracy of full arches manufactured using various 3-dimensional printers / 대한치과재료학회지

Full arch models play an important role in clear aligner orthodontic therapy and the preparation of prosthodontic appliances. Three dimensional (3D) printed full arches are very popular with the benefit of easy production and good mechanical properties for fabricating clear aligner. However, the accuracy of 3D printed full arches after long storage have not been proved yet. The objective of this study was to estimate the long-term accuracy of 3D full arches produced by the four types of 3D printers (stereo-lithography apparatus (SLA), digital light projector (DLP), Polyjet™ (POL), and fused deposition modeling (FDM)) following an accelerated aging treatment. The highest accuracy was produced by POL (before treatment) and SLA (after treatment) group, respectively. Comparisons between absolute mean trueness for the 3D printed full arches before and after treatment indicated that the deviation of the trueness values of FDM group were significantly higher than those of other experimental groups (p<0.05). In addition, all trueness relative errors for FDM group were greater than 0.04 after treatment, which was high compared to those of other experimental groups. Therefore, the long-term storage of full arches fabricated by FDM type 3D printer is not recommended and the 3D printed full arches should be used immediately whenever possible.

Protocolo Clínico para Control de Prótesis Fija Total con Carga Inmediata / Clinical Protocol for Control of an Immediately Loaded Implant-Supported Prosthesis

RESUMEN: Los protocolos odontológicos de controles son guías que tienen por objetivo optimizar la calidad de atención y estandarizar ciertos procedimientos para poder establecer mejores pronósticos. Varias complicaciones se pueden presentar posterior a la instalación de una prótesis fija total con carga inmediata (PFTC), desde el daño de la estructura protésica provisoria hasta la pérdida de la oseointegración de los implantes dentales. La escasa evidencia sobre el comportamiento clínico que se debe tener posterior a este tipo de tratamiento indica la necesidad de confección de un protocolo para poder mejorar las tasas de éxito. Para confeccionar el protocolo clínico se realizó una revisión sistemática de la literatura en la base de datos PubMed. Los filtros de búsqueda fueron ajustados de la siguiente manera. Se utilizaron los términos de búsqueda "immediate loading" AND "full arch" AND "Resonance frequency analysis". Los que fueron sometidos a los criterios de inclusión y exclusión, dando como resultado un total de 15 estudios. Todos los estudios seleccionados son ensayos clínicos controlados donde se encontraron complicaciones como fracturas, desalojos y desgaste de la estructura protésica, entre otros. En los resultados encontrados no existe evidencia sobre el número y rango de sesiones necesarias para el control clínico de una PFTCI. El momento más indicado para la extracción de la prótesis provisoria e instalación de la prótesis definitiva es durante el 3° y 4° mes posterior a la carga inmediata. Existe escasa evidencia sobre el número, momento y tipo de examen imageneológico a solicitar. Por lo que este protocolo clínico será una guía para los controles que se realicen posterior a una instalación de una PFTCI.

ABSTRACT: Dental protocols are guidelines used to optimize service quality and to standardize procedures to establish a better prognosis. There are many complications that can occur after installation of a an immediately loaded implant-supported prosthesis for rehabilitation. These may generate damage to the provisional structure and even loss of osseointegration from the dental implants. Limited evidence on the clinical approach required to monitor these procedures, makes it necessary to establish clinical protocols for treatment control, and increases the success rate. In order to develop such protocols a systematic research was carried out in the Pubmed database. The filters used were "immediate loading", "full arch" and "Resonance frequency analysis". The results were subject to the inclusion and exclusion criteria. A total of 15 studies were selected. All of the studies were randomized clinical trials. An important number of complications were recorded, such as fractures, dislodgment and wear of the prosthesis structure. There is no evidence about the number and range of sessions needed to assess the clinical control of an immediate loading fixed rehabilitation. The best time to remove the provisional prosthesis and install the restorative rehabilitation is during the third and fourth month following immediate loading. Limited evidence was found regarding the number, time and type of radiological images requested for clinical support. Therefore, the clinical protocol developed by the authors will be a guide for future controls related to an immediately loaded implant-supported prosthesis.

Control Clínico en Pacientes Rehabilitados Mediante Prótesis Fija Total con carga Inmediata. Revisión de la Literatura / Clinical Control of Patients Treated with an Immediately Loaded Implant-Supported Prosthesis. A Systematic Review

RESUMEN: Son varias las complicaciones que se pueden presentar posterior a la instalación de una prótesis fija total con carga inmediata (PFTCI), estas pudiesen generar desde el daño de la estructura protésica provisoria hasta la pérdida de la oseointegración de los implantes dentales. La escasa evidencia sobre el comportamiento clínico que se debe tener posterior a este tipo de tratamiento indica la necesidad de controlar mejor estas complicaciones. En esta revisión narrativa, el 3 de marzo de 2016 se realizó una búsqueda electrónica en la base de datos PubMed. Para poder efectuar una investigación acabada los filtros de búsqueda fueron ajustados de la siguiente manera. Se utilizaron los términos de búsqueda "immediate loading" AND "full arch" AND "Resonance frequency analysis". Los que fueron sometidos a los criterios de inclusión y exclusión, dando como resultado un total de 15 estudios. Todos los estudios eran ensayos clínicos controlados, donde se encontraron complicaciones como fracturas, desalojos y desgaste de la estructura protésica, entre otros. Se pudo observar que desde el día de la carga hasta un mes después el valor ISQ (cociente de estabilidad del implante) disminuye, para luego aumentar paulatina y progresivamente. En conclusión, no existe evidencia sobre el número y rango de sesiones necesarias para el control clínico de una PFTCI. El momento más indicado para la extracción de la prótesis provisoria e instalación de la prótesis definitiva es durante el 3° y 4° mes posterior a la carga inmediata. Existe escasa evidencia sobre el número, momento y tipo de examen imageneológico a solicitar. La presencia de complicaciones protésicas posterior a una PFTCI hace necesaria la confección de un protocolo de control clínico para este tipo de tratamiento.

ABSTRACT: There are many complications that can occur following placement with an immediately loaded implant-supported prosthesis in rehabilitation, these may generate damage to the provisional structure and even loss of the osseointegration from the dental implants. Limited evidence about clinical behavior post-installation, creates the need to better assess possible future complications that may arise. In this review, a systematic research was made in the PubMed database. The filters used were "immediate loading", "full arch" and "Resonance frequency analysis". The results were subject to the inclusion and exclusion criteria. A total of 15 studies were selected. All of the studies were randomized clinical trials, many complications were recorded, such as fractures, dislodgement and wear of the prosthesis structure. It was observed that from the first day of immediate loading until the first month, Implant Stability Quotient value decreases, subsequently, progressively increasing. There is no evidence about the number and range of sessions needed to assess the clinical control of a immediate loading fixed rehabilitation. The ideal time for removal of the provisional prosthesis and installation of the restorative rehabilitation, is during the third and fourth month after the immediate loading. Limited evidence was found regarding the number, the time and type of radiological images for clinical support. The possibility of several complications after an installation of a immediately loaded implant-supported prosthesis are very real, therefore is necessary to establish a clinical protocol for controls regarding this treatment.

Precision of the milled full-arch framework fabricated using pre-sintered soft alloy: A pilot study

PURPOSE: This study aimed to evaluate the marginal discrepancy of full-arch frameworks in implant-supported prostheses fabricated using pre-sintered soft alloy (PSA). MATERIALS AND METHODS: Full-arch metal frameworks were fabricated on the edentulous implant model using casting alloy (CA), fully-sintered hard alloy (FHA), and PSA (n = 4 in each group). To evaluate the misfit of the framework to the abutments, the absolute marginal discrepancy (AMD) values of the frameworks were measured in cross-sectional images that had been drawn as part of the triple-scan protocol. The AMD values were compared among the tested alloy groups using the Kruskal-Wallis test, with a post hoc Mann-Whitney U test (α=.05). RESULTS: The FHA and PSA groups showed lower marginal discrepancies than the CA group (P < .001). However, the FHA group did not differ significantly from the PSA group. CONCLUSION: Soft alloy milling is comparable to hard alloy milling, and it is more precise than casting in terms of the marginal fit of implant-supported, full-arch prostheses.

Total intrusion and distalization of the maxillary arch to improve smile esthetics / 대한치과교정학회지

This case report illustrates the successful treatment of a patient with skeletal Class II malocclusion and an unesthetic smile involving excessive gingival display and large buccal corridors. By applying dual buccal interradicular miniscrews, total intrusion of the maxillary dentition along with distalization was induced to improve both the occlusion and smile esthetics. In addition to the conventional cephalometric superimposition, three-dimensional superimposition was performed and evaluated to validate the treatment outcome.

Plaque accumulation beneath maxillary full-arch implant-supported fixed prostheses / 口腔疾病防治

Objective@#To evaluate the plaque distribution on the fitting surface of fixed implant prostheses which were supported by multi-unit abutment. @*Methods @# 21 patients with maxillary full-arch implant-supported fixed prostheses were collected. Plaque accumulation at the fitting surfaces were evaluated 3 months after restoration, by analyzing the digital photographs recorded by Imag e J 2.1.4.7.@*Results@#The average percentage of area covered with plaque was (46.13 ± 7.23)%. Plaque accumulation on the buccal and palatal area were (41.53 ± 3.08) and (53.76 ± 3.07)% respec⁃ tively, with a significant difference (t = 16.750, P < 0.001). The free area (71.86 ± 2.00) % was significantly higher than the anterior area (48.85 ± 2.09)% (t = 40.445, P < 0.001), andalso the middle area (49.33 ± 0.98)% (t = 47.124 , P < 0.001). The plaque percentage was higher when the distance between the implants was shorter.@*Conclusion@#To Minimize the palatal extension and free area of the prostheses, and to maximize the distances between the implants, were helpful to improve the oral hygiene control. It might be the key to keep a good outcome of the maxillary full-arch implant-supported fixed prostheses.

Evaluación de la pérdida osea y del éxito / fracaso de implantes de titanio de posicionamiento inmediato y tardío con carga inmediata, usados para restauraciones de arco completo a 12 meses de su implantación / Evaluation of bone loss and success / failure of titanium implant positioning with immediate and late charge, used in full arch restorations at 12 months of implant

El propósito de esteestudio fue evaluar elnivel óseo y el éxito y fracaso de implantes con carga inmediata posicionados inmediatamentedespués de la extracciónpara rehabilitaciones de arco completo ycompararlos con los resultados obtenidos con implantes situados en alvéolos cicatrizados, en un periodo de 12 meses, para determinar la mejor alternativa de uso. Se efectúo una revisión sistemática en base aensayos clínicos aleatorios prospectivos y los ensayos clínicos aleatorizado o no aleatorizados, controlados o no controlados que evaluaron el fracaso yreabsorción ósea de implantes con carga inmediata posicionados en alveolos post-extracción y en alvéolos cicatrizados en pacientes adultos para rehabilitaciones de arco completo. Los datos de los ensayos clínicos fueron ingresados al software Review Manager®. Se realizaron dos metaanálisis para las distintas variables a analizar y posteriormente un análisis de sensibilidad para eliminar los estudios que causaban sesgo. De un total de 431 implantes analizados, 16 de ellos fracasaron, 11 de los cuales habían sido posicionados inmediatamente luego de la exodoncia. Tres de losautores considerados en la revisión, concuerdan en que hay un mayor éxito y menor pérdida ósea en aquellos implantes posicionados de manera tardía. Para rehabilitaciones implanto-soportadasde arco completo fijas o removibles, el protocolo de posicionamiento tardío, demostró ser una mejor alternativa puesto que manifestó una menor tasa de fracaso y una menor pérdida ósea.

The purpose of this study was to evaluate the bone level and the success and failure of loaded implants positioned immediately after extraction for full-arch restorations and compare the results obtained with implants placed in healed alveoli, in a period of 12 months, to determine the best alternative. A systematic review based on prospective randomized clinical trials, and randomized or nonrandomized controlled and uncontrolled trials evaluating failure and bone resorption of immediate loaded implants, positioned in post extraction and healed sockets in adult patients for full arch rehabilitations. Data from clinical trials were entered into Review Manager® software. Two meta-analyzes for different variables to analyze and subsequently a sensitivity analysis to eliminate bias caused studies were performed. From a total of 431 implants studied, 16 of them failed, 11 of which had been positioned immediately after the extraction. Three of the authors of the review considered agree that there are more successful and less bone loss in implants positioned so late. To implant-supported full-arch restorations fixed or removable, late positioning protocol proved to be a better alternative since it showed a lower failure rate and less bone loss.

Próteses totais fixas tipo protocolo bimaxilares. Relato de caso / Fixed full-arch prosthesis type protocol bimaxillary. Case report

Os implantes osseointegrados promoveram importantes mudanças nas formas de reabilitação de pacientes parcial ou totalmente desdentados. Os pacientes totalmente desdentados apresentam clara predileção pelas próteses fixas implantossuportas, sobretudo porque proporcionam maior eficiência mastigatória e conforto, menos reparo e manutenção, além de favorecer o aspecto psicológico, uma vez que elimina o caráter removível das overdentures. Dentre os possíveis desenhos de próteses fixas as do tipo protocolo são as que apresentam maior aplicação clínica, e se caracterizam na mandíbula pela colocação de 4 a 6 implantes na região anterior, entre os forames mentuais, e cantilever distal bilateral para substituir os dentes posteriores. Na maxila recomenda-se a colocação de 6 a 8 implantes. Neste tipo de prótese utiliza-se uma infraestrutura metálica e uma base de resina para uni-la aos dentes de resina acrílica. O objetivo deste trabalho foi relatar um caso clínico de próteses totais fixas tipo protocolo bimaxilares, em que foram adotados critérios bem definidos de diagnóstico e planejamento, e empregadas técnicas cirúrgicas e protéticas com fundamentação científica.

The dental implants promoted important changes in the forms of rehabilitation of partially or fully edentulous patients. Edentulous patients show clear preference for implant-supported fixed prosthesis, mainly because they provide greater chewing efficiency and comfort, less repair and maintenance, in addition to promoting the psychological aspect, considering that eliminates the character removable of overdentures. Among the possible designs of the fixed prosthesis, the type protocols are the which have greater clinical application, and characterized by placing the jaw 4-6 implant in the anterior region between the foramina mentuals, and bilateral distal cantilevers to replace the posterior teeth. In the maxilla is recommended to put 6-8 implants. In this type of prosthesis is used a metal infrastructure and a resin base to attach it to the teeth of acrylic resin. The objective of this study was to report a case of protocol type full-arch fixed prosthesis bimaxillaries with employment of well-defined criteria for diagnosis and planning, and surgical and prosthetic techniques scientific evidence-based.

Maxillary Full Arch Fixed Prosthesis: Clinical Laboratory Procedures and Rehabilitation with Milled Titanium Prosthesis.

Maxillary teeth are the focal point of human smile. Restoring the edentulous maxilla with implant prosthetics is the most challenging area in implant dentistry. Several techniques have been described for the successful restoration of the edentulous mandible/maxilla. Fixed-detachable prostheses with either hybrid prosthesis design or conventional implant supported fixed partial dentures and implant-retained/supported over dentures are some examples. A clinical report is presented describing the clinical and laboratory procedures involved in the fabrication of a copy milled fixed full arch maxillary prosthesis. Similar procedures may be followed in the making of a fixed full arch copy milled mandibular prosthesis.

Técnica todo sobre -4 y carga inmediata para rehabilitación del maxilar superior: reporte de caso clínico / All on -4 technique and immediate loading for maxilla rehabilitation a clinical case report

La Técnica TODO SOBRE -4 (All-on-4) desarrollada por el Dr. Paulo Maló, está basada en la rehabilitación completa de los maxilares con una prótesis fija de carga inmediata sobre 4 implantes adecuadamente distribuidos; 2 implantes angulados posteriores y 2 implantes axiales anteriores, sin la utilización de injertos óseos. En este trabajo presentamos un caso clínico de rehabilitación completa del maxilar superior con la técnica Todo Sobre -4

The All-on-4 technique developed by Dr. Paulo Maló, is based on the full arch rehabilitation of the jaws with a fixed prostheses on four implants immediately loaded and adequately distributed; 2 tilted posterior implants and 2 axial anterior implants without the need of bone grafts. In this work we present a clinical case of full arch rehabilitation of the maxilla with the All-on-4 technique

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.