Influence of pretreating radicular dentin with different polyacrylic acids and isopropanol on the retention of posts.

STATEMENT OF PROBLEM: The optimal pretreatment of radicular dentin before cementing a post with glass ionomer cement is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the retention of prefabricated tapered titanium posts to endodontically treated teeth after applying different pretreatment protocols on the radicular dentin. MATERIAL AND METHODS: The coronal part of 32 single-rooted human teeth was removed 1-mm coronally to the cemento-enamel junction. All specimens received endodontic treatment, and the root canals were prepared with an instrument to a depth of 10 mm to receive a titanium post. The dentin walls of each specimen were roughened with a hand-held diamond cutting instrument. The specimens were randomly divided according to the surface treatments into 4 groups (n=8): KW: etched with 20% to 30% polyacrylic acid (PAA) (Ketac Conditioner) and rinsed with water; KWI: etched with 20% to 30% PAA, rinsed with water and 70% isopropanol; DW: etched with 30% to 50% PAA (Durelon Liquid) and rinsed with water; DWI: etched with 30% to 50% PAA, rinsed with water and 70% isopropanol. The prefabricated titanium posts were airborne-particle abraded and cemented with glass ionomer cement. The specimens were fixed in custom-made brass cylindrical holders with autopolymerizing acrylic resin with the holder parallel to the long axis of the post. All specimens were stored in water for 3 days at 37 °C. Retention was evaluated using a tensile test with a universal testing machine (Zwick Z010) at a crosshead speed of 2 mm/min. Data were statistically analyzed with a 1-way ANOVA, followed by the Tukey post hoc test for pairwise comparisons between groups (α=.05). RESULTS: Mean ±standard deviation retention values ranged from 201.8 ±55.5 N (KW) to 328.1 ±70.9 N (DWI). Groups DWI and KWI (316 ±58.3 N) showed statistically higher retention values than group KW (P<.05) but did not significantly differ from retention values obtained in group DW (P>.05). CONCLUSIONS: An additional final rinse with isopropanol after using PAA increased the retention of the post significantly for all groups. Although group DWI achieved the highest retention values, pretreatment of radicular dentin as in group KWI may also be considered.

Estudio in vitro del ajuste de supraestructuras pasivadas sobre implantes múltiples / In vitro study of the adjustment of passivated suprastructures on multiple implants

Objetivo: Comparar dos procedimientos de soldadura convencionales empleando una aleación de Cr-Co, para co- nectar barras coladas seccionadas a ser fijadas sobre implantes. Materiales y métodos: A partir de un modelo maes- tro que representa un maxilar desdentado con cuatro implan- tes, se confeccionaron veinte (n=20) probetas seccionadas en tres partes. Se conformaron dos grupos, cada uno con diez (n=10) ejemplares. Una vez acondicionadas, fueron atornilla- das al modelo maestro. Su desajuste inicial se analizó utili- zando una lupa estereoscópica, con una cámara incorporada y un software. Las partes fueron soldadas empleando un pro- cedimiento diferente para cada grupo. Las correspondientes al Grupo I se invistieron en un block refractario a base de sílico-fosfato. Las del Grupo II se montaron en una estructu- ra metálica Clever Spider. El desajuste fue mensurado y los resultados procesados estadísticamente. El nivel de significa- ción fue establecido en p<0,05. Resultados: El Grupo I tuvo un desajuste inicial de 97,30±13,81µm y el Grupo II de 98,53±11,24µm. Luego de la soldadura, el Grupo I registró 98,53±17,17µm, 1,23µm mayor respecto al inicial. En el Grupo II se observó 103,13±17,61µm, 4,60µm por encima del original. Se analizaron mediante prue- ba t de Student; en ambos casos el resultado fue de p>0,05. Al comparar entre sí los grupos I y II, por medio de la prueba t y de comprobación no paramétrica de Mann-Whitney, se ob- servaron diferencias no significativas, p=0,41 y p=0,38 res- pectivamente (AU)

Aim: Compare two conventional welding procedures us- ing a Cr-Co alloy, to connect sectioned cast bars to be fixed on implants. Materials and methods: From a master model representing a toothless jaw with four implants, twenty (n=20) specimens sectioned into three parts were made. Two groups were formed, each with ten (n=10) specimens. Once conditioned, they were screwed to the master mod- el. Its initial mismatch was analyzed using a stereoscop- ic magnifier, with a built-in camera and a software. The parts were welded using a different procedure for each group. Those corresponding to Group I were invested in a refractory block based on silyl-phosphate. Those of Group II were mounted on a Clever Spider metal structure. The mismatch was measured, and the results processed statisti- cally. The level of significance was established at p<0.05. Results: Group I had an initial mismatch of 97.30 ±13.81µm, and Group II of 98.53±11.24µm. After welding, Group I registered 98.53±17.17µm, 1.23µm higher than the initial one. In Group II, 103.13±17.61µm was observed, 4.60µm above the original. They were analyzed using Stu- dent's t test; in both cases the result was p>0.05. When com- paring groups I and II, using the t-test and the Mann-Whitney nonparametric verification, non-significant differences were observed, p=0.41 and p=0.38 respectively. Conclusions: Under the conditions of this study, it was ob- served that the two welding methods analyzed were reliable for joining metallic superstructures without affecting their final fit (AU)

Consensos referidos a conceptos rehabilitadores en la enseñanza de la odontología. Parte I: conceptos generales y diseño de la prótesis parcial removible / Consensus referring rehabilitative concepts in the teaching of dentistry. Part I: general concepts and design of removable partial prosthesis

En este artículo se desarrolla el consenso alcanzado entre profesores, referido a los conceptos generales, componentes y la secuencia del diseño de la prótesis parcial removible, durante la formación del odontó-logo en el ámbito de la Facultad de Odontología de la Universidad de Buenos Aires (AU)

This article develops the consensus between professors on the general concepts, components, and the sequence of the design of the partial removable prosthesis during the training of the dentist in the field of the Faculty of Dentistry of the University of Buenos Aires (AU)

Confección de prótesis de carga inmediata mediante barras articuladas: componentes, modo de uso y longitud de la barra en función de la localización / Fabrication of immediately loaded prostheses using articulated bars: components, method of use and bar length depending on the location

En la implantología actual, la confección de prótesis de carga inmediata se ha convertido en un procedi-miento de rutina. Contar con elementos pre-formados con un correcto ajuste al implante o transepitelial so-bre el que se trabaja, minimiza el tiempo de trabajo sin renunciar a la eficiencia. En el presente trabajo se muestran elementos preformados articulados para la realización de prótesis de carga inmediata y su forma de uso, así como un análisis biomecánico de las estructuras para conocer su repercusión en las distintas fuerzas recibidas durante la masticación. Resultados: Al aplicar la carga en la zona central de la barra (paralela a los implantes), la tensión máxima recibida en la zona correspondiente al extremo de la barra sufre variaciones importantes, desde 128 Mpa en la longitud de 13 mm hasta un máximo de 391 Mpa (megapascales) en la longitud de 5 mm, siendo la ten-sión máxima, media para todas las medidas, de 242 Mpa (+/-96,76). En el ensayo de las diferentes medi-das de la barra se observa también una tensión cre-ciente para longitudes de barra a partir de 7 mm, al aplicar la tensión en la zona media de la estructura, por lo que longitudes entre 5 y 7 mm pueden consi-derarse prácticamente con la misma distribución de tensiones hacia los extremos y en la zona de unión. En conclusión, las barras articuladas son un elemento de confección de prótesis provisionales de carga in-mediata de gran utilidad, que pueden confeccionarse de forma rápida y generan un comportamiento bio-mecánico predecible (AU)

In current implantology, the fabrication of immediately loaded prostheses has become a routine procedure. Being able to have pre-formed elements with a correct fit to the implant or transepithelial on which we are working minimizes working time without sacrificing efficiency. Material and methods: We show articulated preformed elements for immediate loading prostheses and how they are used, as well as a biomechanical analysis of the structures to determine their repercussion on the different forces received during mastication. Results: When the load is applied in the central area of the bar (parallel to the implants) the maximum stress received in the area corresponding to the end of the bar undergoes significant variations, from 128 Mpa in the 13 mm length to a maximum of 391 Mpa in the 5 mm length, the average maximum stress for all the measurements being 242 Mpa (+/-96.76). In the test of the different bar sizes we can also observe an increasing stress for bar lengths from 7 mm onwards when applying the stress in the middle zone of the structure, so that lengths between 5 and 7 mm can be considered to have practically the same stress distribution towards the ends and in the joint zone. Conclusions: Hinged bars are a very useful fabrication element for immediately loaded provisional prostheses, which can be fabricated quickly and generate a predictable biomechanical behavior (AU)

Coronas cementadas comparado con coronas atornilladas para pacientes con restauraciones fijas implantosoportadas / Cement-retained versus screw-retained crowns in patients with implant rehabilitation

RESUMEN: Introducción: Los implantes dentales se han transformado en una opción de tratamiento de suma relevancia para pacientes parcial o totalmente desdentados. El éxito del tratamiento puede verse afectado por la elección del tipo de retención de estos (cementada o atornillada). A pesar que ambas presentan ventajas, aún no existe consenso sobre el mejor tipo de retención para restauraciones fijas implantosoportadas. Métodos: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. Resultados y conclusiones: Identificamos 14 revisiones sistemáticas que en conjunto incluyeron 43 estudios primarios, de los cuales cinco corresponden a ensayos aleatorizados. De estos, solamente dos ensayos responden a la pregunta de interés de manera directa. Concluimos que las coronas atornilladas podrían aumentar levemente el riesgo de pérdida de implante a largo plazo, podrían resultar en nula o poca diferencia en el riesgo de pérdida de implante a mediano plazo, reabsorción ósea y periimplantitis, pero la certeza de evidencia ha sido evaluada como baja. Por otro lado, no es posible establecer con claridad si las coronas cementadas disminuyen el riesgo de complicaciones estéticas y protésicas, ya que la certeza de la evidencia existente ha sido evaluada como muy baja.

ABSTRACT: Introduction: Dental implants have become a highly relevant treatment option for partially or totally edentulous patients. Implant retention systems (cemented or screwed) can influence the treatment success. Although both have advantages, there is still no consensus on the best type of retention for implant-supported fixed restorations. Methods: We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. Results and conclusions: We identified 14 systematic reviews including 43 primary studies overall, of which five were randomized trials. Of these, only two trials answer the question of interest. We concluded that screw-retained crowns may increase long-term implant loss, may make little or no difference in the risk of medium-term implant loss, bone resorption, and peri-implantitis, but the certainty of the evidence has been assessed as low. On the other hand, it is not possible to clearly establish whether cemented crowns reduce the risk of cosmetic and prosthetic complications, since the certainty of the evidence has been assessed as very low.

Prótesis sobre implantes: ¿atornillada o cementada? / Implant supported prosthesis: screw retained or bonded?

El objetivo de este artículo es revisar la evidencia científica existente acerca de los tipos de retención protética fija sobre implantes: atornillada, cementada y cemento-atornillada. Fueron evaluadas sus ventajas y desventajas a fin de facilitar al clínico la elección del sistema de retención en el tratamiento rehabilitador con implantes. Si bien la evidencia científica no es concluyente, la prótesis atornillada presentaría más complicaciones técnicas, y las cementadas, más complicaciones biológicas. Por ello, las prótesis cemento-atornilladas podrían ser en la actualidad una opción de elección, por su versatilidad en la rehabilitación implanto-soportada, combinando las ventajas de cada tipo de retención (AU)

The objective of this article is to review the existing scientific evidence about the different types of retention of fixed prosthetic on implants: screwed, cemented and cement-screwed. The advantages and disadvantages of them were evaluated in order to facilitate the clinician's choice of the retention system in the rehabilitation treatment with implants. Although the scientific evidence is inconclusive, the screwed prosthesis would present more technical complications, while the cemented, more biological complications. Therefore, cement-screwed prostheses could be an option of choice, due to their versatility when rehabilitating an implant, combining the advantages of each type of retention (AU)

Digital vs Conventional Workflow for Screw-Retained Single-Implant Crowns: A Comparison of Key Considerations.

PURPOSE: To evaluate patient perception and operating time of digital (DW) and conventional (CW) workflows for the rehabilitation of a screw-retained, single-implant crown. MATERIALS AND METHODS: A convenience sample of 10 patients with single implants in posterior sites was recruited for treatment with screw-retained single crowns, fabricated with either a DW or a CW protocol. Operating time and clinical adjusting time were recorded with a stopwatch, and patient preference and self-perception of the esthetic outcome were evaluated with a visual analog scale. RESULTS: The mean operating time for the DW crowns was 16:21 minutes and for the CW crowns was 28:28 minutes. The mean total adjustment times were 118.1 seconds for the DW protocol and 181.5 seconds for the CW protocol. The mean score regarding self-perception of the esthetic outcome was 73 for DW crowns and 69 for CW crowns; for discomfort, the mean score was 15.5 for DW and 62 for CW. CONCLUSION: The DW approach resulted in a time reduction for both the impression phase and operative time.

Can intra-radicular cleaning protocols increase the retention of fiberglass posts? A systematic review

Abstract The presence of residues within the root canal after post-space preparation can influence the bond strength between resin cement and root dentin when using fiberglass posts (FGPs). Currently, there is no consensus in the literature regarding what is the best solution for the removal of debris after post-space preparation. This systematic review involved "in vitro" studies to investigate if cleaning methods of the root canal after post-space preparation can increase the retention of FGPs evaluated by the push-out test. Searches were carried out in PubMed (MEDLINE) and Scopus databases up to July2017. English language studies published from 2007 to July 2017 were selected. 475 studies were found, and 9 were included in this review. Information from the 9 studies were collected regarding the number of samples, storage method after extraction, root canal preparation, method of post-space preparation, endodontic sealer, resin cement, cleaning methods after post-space and presence of irrigant activation. Five studies presented the best results for the association of sodium hypochlorite (NaOCl) and ethylenediamine tetra-acetic acid (EDTA), while in the other 4 studies, the solutions that showed improved retention of FGPs were photon-induced photoacoustic streaming (PIPS), Qmix, Sikko and EDTA. The results showed heterogeneity in all comparisons due to a high variety of information about cleaning methods, different concentrations, application time, type of adhesive system and resin cements used. In conclusion, this review suggests that the use of NaOCl/EDTA results in the retention of FGPs and may thus be recommended as a post-space cleaning method influencing the luting procedure.

An Alternative Prosthetic Approach for Rehabilitation of Two Edentulous Maxillectomy Patients: Clinical Report.

Obturator prosthesis is a common treatment method for maxillectomy patients for maintaining their oronasal separation and resuming their social lives. After tumor resection, the remaining anatomical structures have a significant effect on prosthesis retention. The present study describes the rehabilitation of two maxillectomy patients after cancer surgery using a prosthesis consisting of a denture and a special retentive obturator that is positioned in the anatomical undercuts of the nasal cavity. These patients have undergone total and subtotal maxillectomy surgery after the diagnosis of squamous cell carcinoma. The systemic and local health status of the total maxillectomy patient was not suitable for zygomatic implant surgery. Only one osseointegrated dental implant was placed into the left maxillary tuberosity area in the subtotal maxillectomy patient. In addition, the quality, vertical height, and horizontal width of the remaining bone structures in the maxilla limited the use of osseointegrated dental implants. Mechanical prosthesis retention was provided using a multiunit retentive mechanism composed of an orthodontic forsus fatigue resistant device (OFFRD), two Herbst appliances, and an acrylic piece associated with healthy keratinized mucosa. The OFFRD could easily apply a consistent force and push the acrylic pieces toward the retentive undercut under the control of the two Herbst appliances. Two OFFRD units in different directions were designed for the total maxillectomy patient, while only one OFFRD unit was placed on the opposite side of the osseointegrated implant in the subtotal maxillectomy patient. A sufficient retention was obtained for both patients. The patients were satisfied, and no major complications were observed in periodic controls.

Evaluation of resistance against bacterial microleakage of a new conical implant-abutment connection versus conventional connections: an in vitro study.

The aim of the present in vitro study was to evaluate bacterial microleakage from inside to outside the implant-abutment assembly in a new design of internal conical connection compared to eight different internal connections. The design of this connection should prevent or limit microbiologic leakage into the surrounding implant tissue, that could contribute to infections without bone loss (mucositis) or with bone loss (peri-implantits). In order to investigate bacterial microleakage, the inner part of each system was inoculated with an Escherichia coli suspension. Eight different groups were considered; each group was composed of 10 dental implants, for a total of 80 implants. Groups 1-7 were considered controls, while group 8 was the test connection (an internal connection characterized by a double taper principle). Results showed that in control implants (Group 1 to 7), little microleakage was observed after the first 6 hours (500 CFU/ µl) and, after 24 hours of incubation, they showed a significant bacterial contamination in all samples (>100.000 CFU/ µl). In group 8 (test connection) no contamination was found in the first 6 hours, with 7 out of 10 implants showing no contamination even after 96 hours. Statistically significant differences were found between Group 8 and the other groups (p<0.05), whereas no significant differences were found among implants of the control groups (from group 1 to 7). Within the limits of the present study, the new connection studied presented significantly less microleakage at 96 h in comparison with the other control internal connections.

Three-Dimensional Displacement of Nine Different Abutments for an Implant with an Internal Hexagon Platform.

PURPOSE: Clinicians need to know whether there are any differences among the many abutment options available for restoring a particular implant. This study aims to compare nine abutments for one implant system for positional changes between hand tightening and torqueing. MATERIALS AND METHODS: Nine Tapered Screw-Vent (TSV) implants were placed into a resin block. Five specimens of nine different abutments (n = 45) were tried in one of the nine implants. Initially, the abutments were torqued to 20 Ncm to represent hand tightening. Abutments were tightened to 30 Ncm using a torque driver as recommended by the manufacturer for final seating. Images were recorded in 12-second intervals for approximately 10 minutes after the torque was applied. The spatial relationship of the abutments to the resin block was determined using three-dimensional digital image correlation. Commercial image correlation software was used to analyze the displacements. Mean displacements for the nine different abutments were calculated in all three dimensions and for overall displacement in space. A t test with a step-down Bonferroni correction was used for a pairwise comparison of each abutment's mean displacements to the other abutments to determine statistical differences (α = .05). RESULTS: The Atlantis titanium, Inclusive titanium, and Legacy zirconia abutments showed mean displacements that were statistically significantly higher than other abutments in the horizontal direction. The overall three-dimensional displacement of the Atlantis titanium abutment after an applied 30-Ncm torque was significantly higher than that of six of the other eight abutments (P < .0144). CONCLUSION: Within the limitations of this in vitro study, the Zimmer PSA demonstrated less displacement between hand tightening and torqueing than the Atlantis titanium or Inclusive titanium abutments when used to restore a TSV implant.

In Vitro Retentive Effect of Groove, Sandblasting, and Cement Type on Stainless Steel Crowns in Primary Molars.

PURPOSE: The purpose of this study was to evaluate and compare the effect of placing vertical grooves, sandblasting, and luting cements on the retention of stainless steel crowns (SSCs). METHODS: Eighty extracted primary molars were mounted in acrylic blocks. Specimens were divided into Group 1 (RelyX U200) and Group 2 (Smart Cem2). Teeth in each group were further subdivided into Subgroup A (no vertical grooves and no sandblasting), Subgroup B (vertical grooves), Subgroup C (sandblasting of crowns), and Subgroup D (vertical grooves and sandblasting of crowns). After cementation, SSCs were pulled off using a universal testing machine. One-way analysis of variance was used for statistical analyses. RESULTS: In Groups 1 and 2, the highest retentive strengths were found in Subgroup D (1,124 and 783 kPa, respectively), followed by Subgroup C (1,066 and 748 kPa, respectively), Subgroup A (762 and 356 kPa, respectively), and Subgroup B (743 and 314 kPa, respectively). Retentive strength in Group one was significantly higher than in Group two; Subgroups A and B were significantly lower than C and D. CONCLUSIONS: RelyX U200 showed higher retentive strength than Smart Cem2. Sandblasting increased the retention strength, whereas a vertical groove had no significant effect on retention.

A systematic review of factors associated with the retention of glass fiber posts

This study aimed to identify factors that can affect the retention of glass fiber posts to intra-radicular dentin based on in vitro studies that compared the bond strength (BS) of GFPs cemented with resin cements. Searches were carried out in PubMed and Scopus until December 2013. Bond strength values and variables as type of tooth, presence of endodontic treatment, pretreatment of the post, type of bonding agent (if present), type of cement and mode of cement application were extracted from the 34 included studies. A linear regression model was used to evaluate the influence of these parameters on BS. The presence of endodontic treatment decreased the BS values in 22.7% considering the pooled data (p = 0.013). For regular cement, cleaning the post increased BS when compared to silane application without cleaning (p = 0.032), considering cleaning as ethanol, air abrasion, or phosphoric acid application. Applying the cement around the post and into root canal decreased the resistance compared to only around the post (p = 0.02) or only into root canal (p = 0.041), on the other hand, no difference was found for self-adhesive resin cement for the same comparisons (p = 0.858 and p = 0.067). Endodontic treatment, method of cement application, and post pretreatment are factors that might significantly affect the retention of glass-fiber posts into root canals mainly when cemented with regular resin cement. Self-adhesive resin cements were found to be less technique-sensitive to luting procedures as compared with regular resin cements.

Evolução dos sistemas de retenção, fixação e ancoragem extraoral na reabilitação bucomaxilofacial: revisão sistemática / Evolution of retention, fixation and anchorage extraoral in maxillofacial rehabilitation systems: a systematic review

Introdução: A utilização de próteses bucomaxilofaciais é de extrema importância para a reintegração no convívio social dos pacientes acometidos de deformidades congênitas ou adquiridas. Tendo em vista os avanços dos sistemas de retenção, fixação e ancoragem extraoral na reabilitação bucomaxilofacial realizou-se revisão sistemática. Objetivos: verificar a evolução das retenções das próteses bucomaxilofaciais comparando os sistemas osseointegrados, aos sistemas não osseointegrados, analisando algumas variáveis como: taxa de sobrevivência dos implantes ao longo do tempo, idade média dos pacientes, etiologia do defeito facial e sitio dos sistemas de retenção relacionado ao tipo de prótese, em formato de revisão sistemática. Métodos: Realizou-se busca bibliográfica nas bases de dados PubMed e SCOPUS, após elaboração de estratégias de busca, obteve-se 2630 artigos onde foram analisados títulos, resumos e eliminadas duplicidades. Resultados: Obteve-se 25 artigos pré-selecionados que passaram pelos critérios de inclusão e exclusão sendo eleitos 13 artigos para a revisão sistemática. Conclusão: As próteses retidas por implantes superam os sistemas convencionais. A perda dos implantes foi muito pequena nos estudos analisados, apesar do tempo de acompanhamento ser relativamente curto e dos protocolos distintos de tratamento. A idade adulta entre a quarta e quinta década de vida foi a de maior prevalência. A etiologia mais incidente são as neoplasias. Os sistemas osseointegrados fixados por implantes por retenção barra clipe se localizam mais na região auricular e retenção magnética nas regiões nasal e orbital. Os sistemas não osseointegrados, a retenção anatômica é mais utilizada na região ocular, retenção mecânica na região orbital e o uso da retenção por adesivos nas regiões nasal e orbital.

Introduction: The use of maxillofacial prostheses is the most importance for reintegration into social life of patients suffering from congenital or acquired deformities. Given the advances in retention, fixation and extraoral anchorage systems in maxillofacial rehabilitation got systematic review. Objectives: To observe the evolution of the retentions of maxillofacial prostheses comparing osseointegrated systems, non osseointegrated systems, analyzing some variables such as survival rate of implants over time, mean patient age, etiology of facial defect and place restraint systems related kind of prosthesis, in a systematic review format. Methods: We performed a literature search in PubMed and SCOPUS database, after preparation of search strategies, we obtained 2630 articles where were checking titles, abstracts and eliminated duplicates were analyzed. Results: We obtained 25 pre-selected articles that passed the criteria for inclusion and exclusion being elected 13 articles for systematic review. Conclusion: The dentures retained by implants outperform conventional systems. The loss of the implants was very small in the analyzed studies, although the follow-up time is relatively short and the different treatment protocols. Between the fourth and fifth ages of life was the most prevalent. The most frequent etiology are neoplasms. Osseointegrated systems for fixed for implants retention bar clip are located more auricular and magnetic retention in the regions nasal and orbital. Non osseointegrated systems, anatomical retention is most commonly used in the ocular region, mechanical retention in orbital region and the use of adhesives for retention in the regions nasal and orbital.

Uso de implantes zigomáticos na fixação de próteses bucomaxilofaciais / Use of zygomatic implants in the fixacion of maxillofacial prothesis

A prótese bucomaxilofacial tem como objetivo a reabilitação de indivíduos com deformidades craniofaciais, decorrentes de traumatismos, más formações congênitas ou tumores. Muitas pesquisas foram realizadas para melhorar a estabilidade e retenção das próteses em pacientes mutilados. Com o advento da osseointegração, a prótese bucomaxilofacial sofreu um grande avanço tornando possível a realização de trabalhos protéticos com estabilidade, qualidade estética e resultados previsíveis. Esse trabalho faz uma revisão de literatura a respeito do uso de implantes zigomáticos na fixação de próteses bucomaxilofaciais...

The maxillofacial prosthetic rehabilitation aims of individuals with craniofacial deformities resulting from trauma, congenital malformations or tumors. Many researches have been done to improve the stability and retention of dentures in patients. With the advent of osseointegration, the maxillofacial prosthesis suffered a major advance making possible the realization of prosthetic works with stability, aesthetic quality and predictable results. This paper reviews the literature regarding the use of zygomatic implants in the fixation of maxillofacial prostheses...

Retrospective multicenter study of 230 6-mm SLA-surfaced implants with 1- to 6-year follow-up.

PURPOSE: Using short implants poses a challenge in implant surgery. Implant surfaces have evolved, making it possible to improve the success of short implants substantially. However, there is still little information about the long-term predictability achieved with short, rough-surfaced implants. The objective of this study was to evaluate the long-term survival rate of 6-mm rough implants. MATERIALS AND METHODS: A retrospective multicenter analysis of the survival of short 6-mm SLA-surfaced implants was conducted. A total of 230 implants placed in 159 patients were included. The follow-up time ranged between 1 and 6 years. RESULTS: Seven of the 230 implants failed, which gives a cumulative survival rate of 96.4%. Two hundred and fourteen implants were placed in the mandible (93.1%), as opposed to 16 placed in the maxilla (6.9%). Five implants failed during the osseointegration period, and two failed after receiving the prosthetic load. No statistically significant differences were found (P < .44). Of the loaded implants, 209 were splinted to other implants, as opposed to 14 that were not. One implant failed in each group, resulting in a 99.5% for the splinted implants and 92.9% for the unsplinted implants. No statistically significant differences were found between the splinted and unsplinted groups (P < .12). CONCLUSIONS: The short implants used in this study displayed high longterm predictability when placed in the mandible and splinted. There is insufficient- information to extrapolate these results to the maxilla and non-splinted implants.

Predictors of peri-implant bone loss during long-term maintenance of patients treated with 10-mm implants and single crown restorations.

PURPOSE: The aim of this retrospective study was to evaluate the predictors of peri-implant bone loss in a sample of patients treated with 10-mm implants and single crowns who underwent periodontal/peri-implant maintenance (PM) in a Mexican private periodontal practice. MATERIALS AND METHODS: Outcomes of a group of systemically healthy, partially edentulous patients attended up to July 2012 were assessed. Patient data were considered for inclusion if they involved treatment of partially edentulous sites with 10-mm-long implants and single crown restorations, as well as at least 3 years of regular PM following implant placement. Peri-implant bone loss was evaluated from data recorded at the most recent examination. Logistic regression analysis was performed to investigate associations between peri-implant bone loss and sex, duration of PM, location and number of implants placed per patient, region of the mouth, smoking status, type of implant, and retention of restoration. RESULTS: A sample of 104 subjects who had been treated with four different types of dental implants and maintained for at least 3 years was selected. Of the 148 implants placed and followed for an average period of continuing PM of 6 years (range, 3 to 15 years), only one implant (1.8%) was lost. The outcomes of logistic regression analysis showed that the independent variables smoking, retention of restoration (cemented vs screw-retained), and type of implant (internal- or external-hex) were found to be correlated with peri-implant bone loss, with odds ratios of 39.64, 4.85, and 0.04, respectively. CONCLUSIONS: Peri-implant bone loss was significantly associated with smoking status, the type of implant (ie, externally hexed), and type of retention (ie, cemented). Overall, all patients maintained low rates of bone loss.

Análise biomecânica de próteses implantossuportadas parafusadas e cimentadas por meio do método dos elementos finitos / Biomechanical analysis of screw and cement-retained implant-supported prostheses via the finite element method

As próteses implantossuportadas podem ser retidas por parafusos ou por meio de cimento. Um fator relevante que pode influenciar a opção por um dos dois tipos de retenção é o comportamento biomecânico supostamente distinto entre eles. Por meio do método dos elementos finitos 3D, foram comparadas as tensões e deslocamentos nos parafusos, implantes, abutments e no tecido ósseo periimplantar de próteses implantossuportadas parafusadas e cimentadas. Foram construídos dos modelos distintos, consistindo em uma prótese fixa metalocerãmica implantossuportada de três elementos, parafusada (PFP) ou cimentada (PFC) Inicialmente, os parafusos de retenção das próteses foram torqueados para se obter o valor da pré-carga. Em seguida, com o parafuso ainda tensionado, cargas verticais(100 N) e oblíquas (100N) foram aplicadas nos modelos...

Immediate loading of an implant with fine threaded neck-bone resorption and clinical outcome of single tooth restorations in the maxilla.

One of the conditions for ensuring success in implant surgery with an immediate loading (IL) protocol is to achieve maximum primary stability (PS) through the use of dental implants with the appropriate design and surface and a properly prepared osseous bed. The aim of this study was to assess the stability, degree of osseointegration, and success rate after inserting an implant with IL in an osseous bed prepared with burs or an ultrasonic device. Twenty-five patients requiring single tooth replacement (tioLogic; Dentaurum, Ispringen, Germany) in the aesthetic zone were divided randomly into the test (K0) and control (K1) groups. The following factors were investigated: primary (PS-ISQ) and secondary (SS-ISQ) stability- implant stability quotient (ISQ value) by Ostell Mentor, initial width of the alveolar ridge, marginal bone loss (MBL), and buccal bone thickness. The effectiveness of the implant treatment 1 year after the surgery was 100% for group K0 and 93.3% for group K1. A significant correlation was observed between PS and MBL after 1 month. No statistically significant differences were noted between the groups with regard to MBL after 6 months (K0 0.5±0.4 mm vs. K1 0.8±1.3 mm), PS-ISQ (K0 70±4 vs. K1 71±4), and SS-ISQ (K0 70±2 vs. K1 72±3). The average ISQ value of 70±4 is sufficient to allow for IL. A high level of PS results in lower MBL.

Effects of lateral cortical anchorage on the primary stability of implants subjected to controlled loads: an in vitro study.

Our aim was to evaluate the effects of lateral cortical anchorage on the primary stability of implants subjected to immediate loading. Implants were placed into bovine bones with monocortical anchorage (implant placed through the cortical bone of the crest) and bicortical anchorage (the crest cortical bone plus one cortical bone on the lateral side). Loads of 25N and 50N were applied to the implants in different cycles. The implant stability quotient (ISQ) was measured before and after the cyclic loadings. Under 25N load there was no difference in ISQ between 1800 cyclic loading and preloading, but the values decreased significantly after 3600 cyclic loading in both groups (p<0.05). Under a 50N load the ISQ value after 1800 and 3600 cyclic loading decreased in the monocortical group (p<0.05), but there was no difference between 1800 cyclic loading and preloading in the bicortical group, and the ISQ in the bicortical group was higher than in the monocortical group after 1800 cyclic loading (p<0.05). Our results suggest that the stability of implants with bicortical anchorage decreased more slowly under higher loads.