Interplay between resin cements and surface-treated Poly-Ether-Ether-Ketone (PEEK): effect of aging

Aim: This study assessed the effect of thermal aging on the interfacial strength of resin cements to surface-treated PEEK. Methods: Ninety-six PEEK blocks were allocated into 4 groups (n=24), according to following surface treatments: SB - sandblasting with aluminum oxide; SA - acid etched with 98% sulfuric acid; CA ­ coupling agent (Visio.link, Bredent) and CO - control group (untreated). Surface roughness (Ra) was measured and one cylinder (1-mm diameter and height) of Rely-X Ultimate - ULT (3M/ESPE) and another one of Panavia V5 - PAN (Kuraray) were constructed on the treated or untreated PEEK surfaces. Half of the samples of each group were thermal aged (1,000 cycles). Samples were tested at a crosshead speed of 1 mm/min in shear mode (µSBS). Ra and µSBS data were compared using one- and three-way ANOVA, respectively, and Tukey's tests. Results: SA and SB samples had the roughest surfaces, while CA the smoother (p<0.001). Thermal aging reduced µSBS regardless the surface treatment and resin cement used. There was interaction between surface treatment and resin cement (p <0.001), with ULT showing higher µSBS values than PAN. SA provided higher µSBS than SB for both resin cements, while for CA µSBS was higher (PAN) or lower than SB (ULT). Conclusion: Aging inadvertently reduces interfacial strength between PEEK and the resin cements. If ULT is the resin cement of choice, reliable interfacial strength is reached after any PEEK surface treatment. However, if PAN is going to be used only SA and CA are recommended as PEEK treatment

Reconstrução da papila interdental usando enxerto de tecido conjuntivo / Reconstruction of the interdental papilla with an underlying subepithelial connective tissue graft. Case report

A literatura odontológica apresenta vários trabalhos relatando técnicas cirúrgicas de reconstrução da papila interdental e quão grande são os desafios para a Periodontia atual, pois este problema está relacionado à perda do septo ósseo interdental e, consequentemente, à perda da papila. Esta ausência pode acarretar limitações estéticas, dificuldade na fonética e impactação de alimentos. Este relato de caso descreve a aplicação clínica de uma técnica, na qual um retalho avançado coronalmente, associado a um enxerto de tecido conjuntivo, é utilizado para reconstrução da papila interdental. Apesar do resultado satisfatório obtido ao final deste caso, ainda são necessários estudos longitudinais em que possamos nos basear e avaliar a previsibilidade das técnicas cirúrgicas que envolvem a reconstrução da papila interdental.

Plataforma switching em região estética: relato de caso / Platform switching in the esthetic zone: case report

A remodelação óssea cervical ao redor de implantes com plataforma convencional, conhecida como saucerização, pode comprometer a manutenção dos tecidos duros e moles peri-implantares, gerando comprometimentos estéticos como recessões e/ou perda de papilas. O conceito de plataforma switching, com o posicionamento da união implante-abutment mais internamente, aumentando o distanciamento entre o osso e a plataforma protética, parece minimizar ou impedir essa reabsorção óssea. O presente trabalho tem o objetivo de apresentar um relato de caso clínico de reabilitação estética anterior, com a utilização de um implante plataforma switching associado a recursos plásticos e protéticos peri-implantares que maximizassem o resultado final. Os resultados clínicos e radiográficos demonstraram preservação dos picos ósseos proximais e das papilas, manutenção da espessura de tecido mole e adequado resultado estético final. A escolha do uso de implantes com essas características de plataforma switching pode ser favorável em áreas estéticas.

Inovação na abordagem em insucessos tardios em implantes osseointegrados: explantação minimamente traumática (Parte 1) / Innovated approach in late failure of osseointegrated implant: Minimally traumatic implant explantation (Part 1)

Introdução: a explantação minimamente traumática é uma técnica em que se usa um dispositivo cônico de rosca anti-horária capaz de romper a osseointegração e desrosquear com facilidade o implante. Objetivo: o objetivo desse artigo é apresentar um relato de caso clínico onde foi usada essa técnica em um caso de insucesso tardio com implantes e comparar a técnica com as demais alternativas de tratamento, mostrando as vantagens e desvantagens de cada. Conclusões: concluiu-se que a nova abordagem de explantação sugere que há a preservação do tecido ósseo peri-implantar e dos dentes adjacentes, havendo uma redução do tempo de tratamento e morbidade associadas às reconstruções ósseas. Mostra-se como uma técnica eficiente para a remoção de implantes, garantindo previsibilidade ao retratamento.

Introduction: The minimally traumatic retrieval implant technique is a treatment that uses a tapered screw counterclockwise device. This tool can break the osseointegration and retrieve the implant easily. Objective: The aim of this paper is to show a clinical case report where this technique was used in implant failure and to show the advantages and disadvantages of other treatment alternatives. Conclusions: This new approach suggests that this explantation can preserve the peri-implant bone tissue and the adjacent teeth, there is a reduction of treatment time and in the morbidity associated with bone reconstruction. It seems an effective technique for removal of implants, ensuring predictability to retreatment.

Coroas cimentadas em implantes de conexão sem parafuso / Cemented crowns in screwless implant connection

A reabilitação protética de implantes por meio de coroas cimentadas é um tema controverso, uma vez que problemas, como a remoção dos excessos de cimento e o acesso ao parafuso do munhão, são descritos na literatura. O objetivo deste trabalho é avaliar, por meio de um caso clínico, a utilização de coroas cimentadas sobre implante com conexão do tipo locking taper na reabilitação protética em região posterior de mandíbula. A conexão locking taper consiste em uma conexão cônica com inclinação de 1 a 1,5º entre o munhão e o implante, sem parafuso, unidos friccionalmente por uma soldadura fria entre metais. A ausência de parafuso torna a conexão locking taper versátil porque possibilita uma cimentação extrabucal das coroas metalocerâmicas nos munhões e inserção do conjunto coroa-munhão livre de excessos de cimento no implante. Selamento bacteriano, estabilidade óssea peri-implantar e redução do número de componentes protéticos são vantagens dessa conexão protética. Concluímos que coroas unitárias cimentadas em implantes locking taper oferecem uma boa opção de tratamento para o edentulismo parcial, no entanto mais estudos são necessários.

The prosthetic rehabilitation with cemented crowns in oral implants is a controversial topic, since problems like removing luting excess and accessing the abutment screw are described in the literature. The aim of this article is to evaluate, through a c1inical case, the application of locking taper implant cemented crowns in posterior mandibular area. Locking taper consists of a screwless 1-1.5° morse taper connection among abutment and implant, united by a frictional cold welding. The screwless quality makes locking taper versatile because it allows an extraoral luting of metaloceramic crowns in implant abutments and insertion of integrated abutment-crown without luting excess in oral implants. Bacterial sealing, bone stability around the implant, reduction in prosthetic components are advantages of this prosthetic connection. The authors concluded that single cemented crowns in locking taper implants offers a good treatment option for partial edentulism, but further studies are suggested.

Protocolo all-on-four em maxila - Discutindo aspectos clínicos e biomecânicos / All-on-four protocol in maxillary arch - Discussion on clinical and biomechanical aspects

Este trabalho tem o objetivo reportar a reabilitação oral de uma paciente com grandes necessidades funcionais e estéticas. Devido à péssima condição clínica de todos os dentes remanescentes, optou-se pela exodontia e indicação de um protocolo all-on-four (tudo sobre quatro) na maxila e um protocolo convencional na mandíbula suportada sobre cinco implantes. O conceito all-on-four consiste em uma modalidade de reabilitação suportada sobre quatro implantes, sendo dois implantes anteriores posicionados axialmente e dois implantes posteriores inclinados. Nesse trabalho, dados da literatura científica referentes aos aspectos clínicos e biomecânicos foram confrontados e discutidos em relação ao caso clínico apresentado. Os autores concluíram que o protocolo all-on-four recuperou satisfatoriamente a função e a estética da paciente, evitando a necessidade de levantamento de seio maxilar. Essa abordagem terapêutica pode ser de grande indicação na clínica, com relativa facilidades cirúrgica e protética, apesar da reduzida evidenciação científica sobre a manutenção de estruturas biológicas e mecânicas em longo prazo quando utilizado em maxila edêntula.

The aim of this study is to report a prosthetic treatment of a functionally and esthetically compromised patient. Due to a difficult clinical situation, all teeth were extracted and the all-on-four protocol was planned for the maxillary arch, with a conventional protocol in the mandibular arch supported by five implants. The all-on-four concept consists of a prostheses supported by four implants, in which two anterior implants are axially placed and two posterior implants are mesially inclined. In this study, data from the literature related to clinical and biomechanical aspects were discussed, considering the clinical case presented. The authors concluded that the all-on-four protocol can rehabilitate the functional and aesthetical aspects avoiding the sinus lift procedure. This therapeutic approach may be indicated as a surgically and prosthetically excellent planning; however, there is little scientific evidence on long-term maintenance of biological and mechanical components when it is used for edentulous maxillary arches.

Evaluation of the reproducibility of two techniques used to determine and record centric relation in angle's class I patients

The centric relation is a mandibular position that determines a balance relation among the temporomandibular joints, the chew muscles and the occlusion. This position makes possible to the dentist to plan and to execute oral rehabilitation respecting the physiological principles of the stomatognathic system. The aim of this study was to investigate the reproducibility of centric relation records obtained using two techniques: Dawson's Bilateral Manipulation and Gysi's Gothic Arch Tracing. Twenty volunteers (14 females and 6 males) with no dental loss, presenting occlusal contacts according to those described in Angle's I classification and without signs and symptoms of temporomandibular disorders were selected. All volunteers were submitted five times with a 1-week interval, always in the same schedule, to the Dawson's Bilateral Manipulation and to the Gysi's Gothic Arch Tracing with aid of an intraoral apparatus. The average standard error of each technique was calculated (Bilateral Manipulation 0.94 and Gothic Arch Tracing 0.27). Shapiro-Wilk test was applied and the results allowed application of Student's t-test (sampling error of 5 percent). The techniques showed different degrees of variability. The Gysi's Gothic Arch Tracing was found to be more accurate than the Bilateral Manipulation in reproducing the centric relation records.

Assessment of painful symptomology in patients with temporomandibular disorders by means of a combined experimental scale

Quantification and assessment of the evolution of painful symptomology in patients with temporomandibular disorders, during the pre-, trans- and post-therapeutic stages is one of the greatest difficulties found by dental surgeons. Various authors have studied and discussed the use of verbal and non-verbal scales for this purpose. Therefore, this study aimed, by means of a combined experimental scale, to assess the evolution of painful symptomology in patients with completely edentulous maxilla and partly edentulous mandible, with Class I or Class II Kennedy prosthetic spaces, treated with flat occlusal appliances, before, during and after 150 of starting treatment. A selection was made of 16 patients with a mean age of fifty-two years, with signs and symptoms of temporomandibular disorders and diminished vertical occlusion dimension. The patients were submitted to treatment with flat occlusal appliances and fortnightly consultations for a period of 150 days. During these consultations, patients recorded their painful symptomology on a combined experimental pain scale. The results obtained were grouped into tables and submitted to the Friedman Test at a level of 5% probability. These revealed statistically significant differences between the values obtained at each assessment made. According to the methodology used and the results obtained, it was concluded that the therapy used was effective and that the experimental scale was efficient for registering the evolution of the symptoms initially detected.