ABSTRACT The immediate rehabilitation of the posterior region of the mandible with dental implants, expands the set of possible actions for the dental surgeon, in the face of tooth loss. The purpose of this study is to describe two cases of single rehabilitation of mandibular molars with hybrid internal tapered implants indicated for immediate loading in post-extraction socket, associated with the maintenance of the prosthetic and peri-implant space. Implants with macrogeometry and surface treatment (Hydrophilic) were used to optimize primary stability, as well as the type of internal connection and prosthetic abutments that allows better accommodation and healing of adjacent tissues, and protection of the bone graft. Different methodologies of surgical guides did not influence the final result. The predictability of associating techniques and components can be observed in the 2-year follow-up. The initial planning combined with the new technologies enable to achieve stable and functional final restorations.

RESUMO A reabilitação imediata da região posterior da mandíbula com implantes dentários, amplia o conjunto de ações possíveis ao cirurgião dentista, frente as perdas dentárias. O intuito desse estudo é descrever dois casos de reabilitação unitária de molares inferiores com implantes cônicos internos híbridos indicados para carregamento imediato em alvéolos pós-extração, associado a manutenção do espaço protético e peri-implantar. Foram utilizados implantes com macrogeometria e tratamento de superfície que otimizassem a estabilidade primária (Hidrofílicos), bem como o tipo de conexão interna e abutments protéticos que permitisse melhor acomodação e cicatrização dos tecidos adjacentes, e proteção do enxerto ósseo. Diferentes metodologias de guias cirúrgicos não influenciaram o resultado final. A previsibilidade da associação de técnicas e componentes pode ser observada no follow-up de 2 anos. O planejamento inicial aliado às novas tecnologias permite restaurações finais estáveis e funcionais.

RESUMO Estudos tem encontrado a associação entre os episódios de bruxismo e a presença dos sinais e sintomas de disfunção temporomandibular (DTM). O objetivo do presente trabalho foi relatar o diagnóstico e terapia paliativa do bruxismo associado à DTM. Paciente, 23 anos, gênero masculino, apresentou-se à clínica odontológica, queixando-se de dor na articulação temporomandibular do lado esquerdo e alteração da forma dos dentes anteriores. Durante a anamnese foi documentado que esse sintoma era recorrente e relatado o hábito de ranger os elementos dentais. No exame clínico observou-se discrepância entre relação cêntrica e máxima intercuspidação habitual, guia protrusiva insatisfatória, presença de facetas de desgaste, estalido e desvio mandibular durante o movimento de abertura bucal. O questionário Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) foi aplicado para diagnosticar a DTM. Por meio de algoritmos específicos essa desordem foi classificada como dor miofascial, deslocamento de disco com redução e osteoartrite, todos acometendo o lado esquerdo. Desta forma, foi proposto a montagem dos modelos em articulador semi-ajustável para mapeamento oclusal e enceramento diagnóstico. Em seguida o ajuste oclusal por desgaste seletivo e acréscimo de material foi executado. Finalizado esse procedimento, a placa estabilizadora da oclusão foi instalada como terapia paliativa para o bruxismo. Esse relato de caso sugere que a abordagem odontológica por meio do ajuste oclusal e placa oclusal, em paciente diagnosticado com bruxismo e disfunção temporomandibular, reduz os sinais e sintomas que afetam os componentes do Aparelho Estomatognático.

ABSTRACT Studies have found the association between episodes of bruxism and the presence of signs and symptoms of temporomandibular disorder (TMD). The aim of the present study was to report the diagnosis and palliative therapy of bruxism associated with TMD. Patient, 23 years old, male gender, presented at dental clinic, complaining of pain in the temporomandibular joint on the left side and alteration of the form of the anterior teeth. During the anamnesis it was documented that this symptom was recurrent and reported the habit of grinding teeth. The clinical examination observed discrepancy between the centric relation and the maximum habitual intercuspation, unsatisfactory protrusive guide, presence of wear facets, clicking and mandibular deviation during mouth opening. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC / TMD) questionnaire was applied to diagnose TMD. By means of specific algorithms this disorder was classified as myofascial pain, disc displacement with reduction and osteoarthritis, all affecting the left side. Thus, it was proposed the assembly of the models in semi-adjustable articulator for occlusal mapping and waxing diagnosis, then the occlusal adjustment by selective wear and material addition was executed. After this procedure, the occlusal splint was installed as a palliative therapy for bruxism. This case report suggests that the dental approach by means of occlusal adjustment and occlusal splint, in a patient diagnosed with bruxism and temporomandibular disorder, reduces the signs and symptoms that affect the components of the Stomatognathic System.

Abstract With the onset of the new coronavirus disease (COVID-19) pandemic, the dental treatment of patients at risk of infection has become quite challenging. In view of this, patients with head and neck cancer may present with oral complications due to anticancer therapy, making dental assistance necessary. Thus, the objective of the study was to review the literature and critically discuss important concerns about the treatment of patients with head and neck cancer during the COVID-19 pandemic. Because dental professionals are in close contact with the main viral transmission routes, this study presents recommendations for management and protection during clinical dental care. The main characteristics and transmission routes of COVID-19 are also discussed. Dental professionals should control pain and the side effects of antineoplastic treatment and use preventive measures for infection control. During this pandemic, patients with head and neck cancer should not undergo elective procedures, even if they do not have symptoms or a history of COVID-19; therefore, in asymptomatic or painless cases, only preventive actions are recommended. In symptomatic or painful cases, precautions for safe interventional treatments must be implemented by following the hygiene measures recommended by health agencies and using personal protective equipment. During health crises, new protocols emerge for cancer treatment, and professionals must act with greater attention toward biosafety and updated knowledge. It is important to offer adequate individualized treatment based on the recommendations of preventative and interventional treatments so that patients can face this difficult period with optimized quality of life.

Abstract Resin cements have led to great advances in dental ceramic restoration techniques because of their ability to bond to both dental structures and restorative materials. Objective The aim of this study was to assess the performance of resin cements when different curing modes are used, by evaluating the degree of conversion and bond strength to a ceramic substrate. Material and Methods Three resin cements were evaluated, two dual-cured (Variolink II and RelyX ARC) and one light-cured (Variolink Veneer). The dual-cured resin cements were tested by using the dual activation mode (base and catalyst) and light-activation mode (base paste only). For degree of conversion (DC) (n=5), a 1.0 mm thick feldspathic ceramic disc was placed over the resin cement specimens and the set was light activated with a QTH unit. After 24 h storage, the DC was measured with Fourier transform infrared spectroscopy (FTIR). For microshear bond strength testing, five feldspathic ceramic discs were submitted to surface treatment, and three cylindrical resin cement specimens were bonded to each ceramic surface according to the experimental groups. After 24 h, microshear bond testing was performed at 0.5 mm/min crosshead speed until the failure. Data were submitted to one-way ANOVA followed by Tukey test (p<0.05). Scanning electron microscopy (SEM) was used for classifying the failure modes. Results Higher DC and bond strength values were shown by the resin cements cured by using the dual activation mode. The Variolink II group presented higher DC and bond strength values when using light-activation only when compared with the Variolink Veneer group. Conclusion The base paste of dual-cured resin cements in light-activation mode can be used for bonding translucent ceramic restorations of up to or less than 1.0 mm thick.

Resumo: O objetivo deste estudo foi mensurar grau de conversão (GC), microdureza Vickers (VH) e módulo de elasticidade (E) de cimentos resinosos polimerizados através de diferentes sistemas cerâmicos. Um disco de 1,5 mm de espessura de cada sistema cerâmico (cerâmica feldspática, dissilicato de lítio e zircônia coberto por cerâmica feldspática) foi utilizado. Três cimentos resinosos duais (Allcem, Variolink II e RelyX U200) e um cimento resinoso quimicamente ativado (Multilink) foram ativados através dos discos de cerâmica. Para os cimentos resinosos duais foi utilizado um aparelho de lâmpada halógena (Optilux 501 a 650 mW/cm2 por 120 s). Amostras polimerizadas sem a interposição do disco de cerâmica foram utilizadas como controle. As amostras foram armazenadas a 37 °C durante 24 h. ATR/FTIR foi utilizado para avaliar a extensão da polimerização nas amostras (n=5). Propriedades micromecânicas - VH e E - dos cimentos resinosos (n=5) foram medidas com um teste dinâmico de indentação. Os dados foram analisados através de análise de variância a dois fatores, teste de Tukey e correlação de Pearson (α=0,05). O GC foi afetado somente pelo tipo de cimento resinoso (p=0,001). Para VH, houve interação entre o tipo de cimento resinoso e o tipo de cerâmica (p=0,045). Os cimentos resinosos duais não apresentaram diferenças significativas nos valores médios de E e valores significativamente maiores que o cimento resinoso quimicamente ativado. O grau de conversão e as propriedades mecânicas dos cimentos resinosos avaliados dependem do seu modo de ativação e do tipo de cerâmica usada na espessura de 1,5 mm. Os cimentos resinosos duais desempenharam melhor que o cimento resinoso quimicamente ativado em todas as propriedades estudadas.

Abstract: The aim of this study was to verify the degree of conversion (DC), Vickers microhardness (VH) and elastic modulus (E) of resin cements cured through different ceramic systems. One 1.5-mm-thick disc of each ceramic system (feldspathic, lithium dissilicate and zircônia veneered with feldspathic) was used. Three dual-cured (Allcem, Variolink II and RelyX U200) and one chemically-cured (Multilink) resin cements were activated through ceramic discs. For dual-cured resin cements was used a conventional halogen light-curing unit (Optilux 501 at 650 mW/cm2 for 120 s). Samples cured without the ceramic disc were used as control. The samples were stored at 37 °C for 24 h. ATR/FTIR spectrometry was used to evaluate the extent of polymerization in the samples (n=5). Micromechanical properties - VH and E - of the resin cements (n=5) were measured with a dynamic indentation test. Data were statistically analyzed with two-way ANOVA, Tukey's test and Pearson's correlation (α=0.05). DC was affected only by the type of resin cement (p=0.001). For VH, significant interaction was detected between resin cement and ceramic (p=0.045). The dual-cured resin cements showed no significant differences in mean values for E and significantly higher values than the chemically-cured resin cement. The degree of conversion and the mechanical properties of the evaluated resin cements depend on their activation mode and the type of ceramics used in 1.5 mm thickness. The dual-cured resin cements performed better than the chemically-cured resin cement in all studied properties.

Aim: To investigate the prevalence of temporomandibular disorders (TMD) in undergraduate students and to correlate its prevalence with occlusal factors and parafunctional habits. Methods: 201 undergraduate students were evaluated. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) was filled out at the beginning of the study, followed by occlusal analysis based on morphological and functional alterations. The identification of tooth grinding and clenching was carried out by self-reports. Statistical analysis was based on chi-square and multivariate logistic regression analyses. p-value for all statistical analysis was set at 5%. Results: According to RDC/TMD, 18.4% of subjects experienced myofascial pain (G-MPD), and 12.4% had joint disorder with disc displacement (G-DD). Tooth clenching was statistically associated with TMD (p=0.000). In the occlusal factors, overjet showed statistically significant correlation only with myofascial pain. No association between functional alteration and TMD was found. No statistically significant correlation was found between G-DD and occlusal alterations or parafunctional habits. Conclusions: Overjet and tooth clenching were correlated with G-MPD. Occlusal alterations or parafunctional habits did not show correlation with G-DD.

The aim of this prospective clinical study was to evaluate patient rehabilitation with two immediately loaded implants and bar-retained mandibular overdentures after 48 months of follow-up. Twenty patients were treated with two implants each; of these, 17 patients were re-evaluated for comparison. Gender, age, plaque index, gingival inflammation, keratinized mucosa, probing depth, bleeding, and implant loss data were recorded, and periapical radiographs were obtained for measurement of marginal bone loss. The results were statistically analyzed with one-way analysis of variance (ANOVA) followed by Student’s t-test and Pearson’s correlation test. To compare the data at baseline and after 48 months, a Wilcoxon Signed Rank Test was performed (α = 0.05). One implant failed (2.9%) during the first year and was replaced. A total of 35 implants were evaluated. Bone loss values were 0.52–2.89 mm (mean, 1.46 mm). Probing depth was 1.75–3.75 mm (mean, 2.22 mm). Correlations were found between bone loss and plaque index and between bone loss and gender, but bone loss did not correlate with gingival inflammation, keratinized mucosa, probing depth, or age. The overall survival rate of the implants was 97.1%. Based on these results, the use of two immediately loaded splinted interforaminal implants to retain an overdenture with a bar attachment is a clinically viable option with a high survival rate.

Restaurar dentes tratados endodonticamente continua sendo desafio para clínicos. Este estudo avaliou o efeito de pinos e técnicas na deformação, resistência à fratura e padrão de fratura de incisivos com canal radicular alargado. Cento e cinco raízes bovinas, tratadas endodonticamente (15 mm) foram divididas em 7 grupos (n=15). Os grupos controle (C), constituídos de raízes não alargadas, foram restauradas com Cpc (núcleo metálico fundido) ou Gfp (pino de fibra de vidro). Nos grupos experimentais os canais foram alargados (F) e restaurados com: GfpAp (Gfp associado com pinos de fibra de vidro acessórios); GfpRc (pino anatômico, reembasado com resina composta) e GfpRcAp (pino anatomizado com resina composta e pinos acessórios). Os dentes foram restaurados com coroas metálicas. Fadiga mecânica foi simulada com 3x10(5)/50 N ciclos. O teste foi realizado a 45º e a deformação (μS) obtida nas superfícies vestibular e proximal. Em seguida, a resistência à fratura (N) e o padrão de fratura foram verificados. Aplicou-se ANOVA e Teste de Tukey (α=0,05). Não houve diferença na deformação. Cpc resultou em menor resistência à fratura e com mais fraturas catastróficas em raízes fragilizadas. As técnicas de reembasamento do pino com resina composta ou o uso de pinos acessórios parecem ser efetivos para melhorar o comportamento biomecânico de raízes fragilizadas.

Restoring flared endodontically treated teeth continues to be a challenge for clinicians. This study evaluated the effect of post types and restorative techniques on the strain, fracture resistance, and fracture mode of incisors with weakened roots. One hundred five endodontically treated bovine incisors roots (15 mm) were divided into 7 groups (n=15). The two control groups were (C) intact roots restored with Cpc (cast posts and core) or Gfp (glass fiber posts). The five experimental groups were (F) flared roots restored with GfpAp (Gfp associated with accessory glass fiber posts), GfpRc (anatomic Gfp, relined with composite resin), and GfpRcAp (anatomized Gfp with resin and accessory glass fiber posts). All teeth were restored with metal crowns. Mechanical fatigue was performed with 3x10(5)/50 N. Specimens were loaded at 45º, and the strain values (μS) were obtained on root buccal and proximal surfaces. Following that, the fracture resistance (N) was measured. One-way ANOVA and Tukey's HSD tests (α=0.05) were applied, and failure mode was checked. No significant difference in strain values among the groups was found. Cpc presented lower fracture resistance and more catastrophic failures in flared roots. Gfp associated with composite resin or accessory glass fiber posts seems to be an effective method to improve the biomechanical behavior of flared roots.

Um ajuste inadequado na interface pilar/implante pode gerar problemas mecânicos e biológicos. Etapas laboratoriais podem induzir a um desajuste em tal interface quando pilares do tipo UCLA calcináveis são utilizados. Este estudo propôs-se a avaliar comparativamente o desempenho de três laboratórios de prótese dentária (Labs A, B e C) pela análise do ajuste vertical de pilares UCLA calcináveis durante o processo de fundição e solda de uma mesma prótese. Quatro próteses fixas foram confeccionadas por cada laboratório utilizando pilares do tipo UCLA calcinável. A avaliação foi feita em microscopia eletrônica de varredura sob aumento de 500 x nas faces mesial e distal de cada elemento da prótese, totalizando 24 medidas por laboratório. Os resultados foram analisados estatisticamente pelo teste de Kruskal-Wallis (p<0,05). Na fundição, os valores apresentados pelos laboratórios diferiram estatisticamente (p=0,004). Após a análise da solda, os valores não apresentaram diferença significante entre os laboratórios (p=0,948). Pode-se concluir que os valores de ajuste obtidos no estágio de fundição de pilares UCLA, podem ser influenciados quando processados por diferentes laboratórios e que o processo de solda convencional, por si só, aumenta o grau de desajuste da infra-estrutura, independente do laboratório que a realizou.

An inadequate fit at the abutment/implant interface can generate mechanical and biological problems. The laboratorial stages could induce misfit in such interface when the castable UCLA abutment type is used. The purpose of this study was to comparatively evaluate the performance of three prosthetic laboratories (Labs A, B and C) by vertical fit analysis of castable UCLA abutments on the casting and soldering stages of the same prosthesis. Four fixed prostheses were built by each laboratory using castable UCLA abutments. The evaluation was made by scanning electron microscopy under 500x magnification in the mesial and distal regions of each element of the prosthesis, totalizing 24 measurements per laboratory. The results were analyzed statistically by Kruskal-Wallis test (p<0.05). In the casting process, the values presented by the laboratories differed significantly to each other (p=0.004). After soldering, the values presented by the laboratories showed no significant difference (p=0.948). It may be concluded that the fit values obtained in the casting stage of UCLA abutments can be influenced when processed by different laboratories, and that conventional soldering itself increased the degree of framework misfit, regardless of which laboratory made it.