Resumo Introdução As evidências científicas atuais têm demonstrado que o tratamento para disfunção temporomandibular deve seguir uma abordagem conservadora e adaptada ao estado psicossocial do paciente. Entretanto, tratamentos visando às alterações oclusais foram utilizados durante anos pelos cirurgiões-dentistas e o abandono destes paradigmas é essencial para o desenvolvimento da Odontologia. Objetivo Objetivou-se avaliar o conhecimento de cirurgiões-dentistas (CD) sobre a relação entre disfunção temporomandibular (DTM) e fatores oclusais. Material e método Foi enviado, por e-mail, um questionário previamente publicado para os CD registrados no Conselho Regional de Odontologia do Piauí, Brasil (n = 2.500) com dados sobre o profissional, sua formação e seu conhecimento sobre DTM e fatores oclusais. O consenso da literatura atual, “padrão-ouro”, foi comparado com as respostas obtidas. Os dados foram analisados descritivamente e através dos testes qui-quadrado e odds ratio (p<0,05). Resultado Quinhentos e cinco CD responderam e 434 compuseram a amostra. A maioria dos participantes era mulher (72,3%), com 7,2 (±6,63) anos de formados, e trabalhava no setor público-privado (39,0%). Os CD foram divididos em dois grupos: GEsp.: especialistas em DTM, Prótese Dentária e/ou Ortodontia (n=234) e GClín.: clínicos gerais e demais especialistas (n=200). GEsp. e GClín. apresentaram respostas similares para a metade das perguntas. Quatro (de seis) perguntas foram respondidas em desacordo com o padrão-ouro: fatores oclusais, interferências em lado de não trabalho, terapia ortodôntica e ajuste oclusal mostraram ser assuntos pouco conhecidos. GEsp. apresentou maior conhecimento com diferença significativa em relação a GClín. acerca da DTM e das interferências oclusais [odds ratio = 2,341 (1,305-4,202), p=0,004]. Conclusão Pode-se concluir que os CD da amostra estudada apresentaram deficiências acerca do conhecimento da relação entre DTM e fatores oclusais. Especialistas em DTM, Prótese Dentária e/ou Ortodontia não demonstraram um maior nível de conhecimento quando comparados aos demais.

Abstract Introduction Current scientific evidence has shown that treatment for temporomandibular disorder should follow a conservative approach that is adapted to the patient’s psychosocial status. However, treatments aiming at occlusal changes have been used for years by dentists and the abandonment of these paradigms is essential for the development of dentistry. Objective The aim of this study was to evaluate the knowledge of dentists on the relationship between temporomandibular disorder (TMD) and occlusal factors. Material and method A previously published questionnaire was sent to the dentists registered at the Regional Council of Dentistry of Piauí, Brazil (n = 2,500) with data about the professional, their training and knowledge about TMD and occlusal factors. The consensus of the current literature, “gold standard”, was compared with the answers obtained. The data were analyzed descriptively and through chi-square test and odds ratio (p <0.05). Result Five hundred and five dentists answered and 434 composed the sample. The majority of the participants was women (72.3%) with 7.2 (± 6.63) years of education and worked in the public-private sector (39.0%). The dentists were divided into Group 1 (GEsp.): specialists in TMD, dental prosthesis and/or orthodontics (n = 234) and Group 2 (GClin.): clinicians and other specialists (n = 200). GEsp. and GClin. presented similar responses for half of the questions. Four (of six) were answered in disagreement with the gold standard: occlusal factors, interference in the balance, orthodontic therapy and occlusal adjustment were little known. GEsp. presented greater knowledge with a significant difference in relation to GClin. regarding TMD and occlusal interferences (odds ratio = 2,341 (1,305-4,202), p = 0.004). Conclusion It can be concluded that the dentists presented deficiencies in the knowledge of the relationship between TMD and occlusal factors. Dentists specialists in TMD, dental prosthesis and/or orthodontics did not demonstrate a higher level of knowledge when compared to the others.

Resumo O objetivo deste estudo foi examinar as taxas de edentulismo no Brasil e fazer projeções para os próximos anos. Os dados foram coletados de três censos nacionais de saúde bucal. O percentual de arcadas edêntulas foi calculado. Foram feitas projeções para 2020, 2030 e 2040, assumindo que o edentulismo segue uma função logística. Também foram realizadas projeções populacionais. A variação anual da proporção de arcadas edêntulas foi de -0,04% para jovens, -0,96% para adultos e 0,76% para idosos. Até 2040, o percentual de arcadas edêntulas será virtualmente zero entre jovens, 1,77% entre adultos e 85,96% entre idosos. O número de jovens vai diminuir levemente; o de adultos vai aumentar e depois diminuir; e o de idosos vai continuar aumentando. Para jovens e adultos, o número de arcadas edêntulas vai diminuir, aproximando-se de 616.000 em 2040. Para os idosos, este número vai aumentar alarmantemente, alcançando mais de 64 milhões em 2040. O edentulismo está diminuindo no Brasil entre jovens e adultos, mas está aumentando e continuará a aumentar nas próximas décadas entre os idosos.

Abstract The aim of this study was to examine the edentulism rates in Brazil and make projections for the next years. Data were collected from three national oral health surveys. The percentage of edentulous jaws was calculated. Projections were made for the years 2020, 2030 and 2040, assuming that edentulism follows a logistic function. Population projections were also performed. Annual change in proportion of edentulous jaws was -0.04% for teenagers, -0.96% for adults and 0.76% for the elderly. By 2040, edentulous jaws will be virtually zero among teenagers, 1.77% among adults and 85.96% among the elderly. Teenagers will slightly decrease in number; adults will increase and subsequently decrease; the elderly will continue to increase. In teenagers and adults, the number of edentulous jaws will decrease, being approximately 616,000 in 2040. In the elderly, it will increase alarmingly, reaching over 64 million in 2040. Edentulism is declining in Brazil among teenagers and middle-aged adults, but is still increasing and will continue to increase for the next decades among the elderly.

Resumo O objetivo deste estudo foi examinar as taxas de edentulismo no Brasil e fazer projeções para os próximos anos. Os dados foram coletados de três censos nacionais de saúde bucal. O percentual de arcadas edêntulas foi calculado. Foram feitas projeções para 2020, 2030 e 2040, assumindo que o edentulismo segue uma função logística. Também foram realizadas projeções populacionais. A variação anual da proporção de arcadas edêntulas foi de -0,04% para jovens, -0,96% para adultos e 0,76% para idosos. Até 2040, o percentual de arcadas edêntulas será virtualmente zero entre jovens, 1,77% entre adultos e 85,96% entre idosos. O número de jovens vai diminuir levemente; o de adultos vai aumentar e depois diminuir; e o de idosos vai continuar aumentando. Para jovens e adultos, o número de arcadas edêntulas vai diminuir, aproximando-se de 616.000 em 2040. Para os idosos, este número vai aumentar alarmantemente, alcançando mais de 64 milhões em 2040. O edentulismo está diminuindo no Brasil entre jovens e adultos, mas está aumentando e continuará a aumentar nas próximas décadas entre os idosos.

Abstract The aim of this study was to examine the edentulism rates in Brazil and make projections for the next years. Data were collected from three national oral health surveys. The percentage of edentulous jaws was calculated. Projections were made for the years 2020, 2030 and 2040, assuming that edentulism follows a logistic function. Population projections were also performed. Annual change in proportion of edentulous jaws was -0.04% for teenagers, -0.96% for adults and 0.76% for the elderly. By 2040, edentulous jaws will be virtually zero among teenagers, 1.77% among adults and 85.96% among the elderly. Teenagers will slightly decrease in number; adults will increase and subsequently decrease; the elderly will continue to increase. In teenagers and adults, the number of edentulous jaws will decrease, being approximately 616,000 in 2040. In the elderly, it will increase alarmingly, reaching over 64 million in 2040. Edentulism is declining in Brazil among teenagers and middle-aged adults, but is still increasing and will continue to increase for the next decades among the elderly.

Objective The purpose of this study was to assess the influence of conditioning methods and thermocycling on the bond strength between composite core and resin cement. Material and Methods Eighty blocks (8×8×4 mm) were prepared with core build-up composite. The cementation surface was roughened with 120-grit carbide paper and the blocks were thermocycled (5,000 cycles, between 5°C and 55°C, with a 30 s dwell time in each bath). A layer of temporary luting agent was applied. After 24 h, the layer was removed, and the blocks were divided into five groups, according to surface treatment: (NT) No treatment (control); (SP) Grinding with 120-grit carbide paper; (AC) Etching with 37% phosphoric acid; (SC) Sandblasting with 30 mm SiO2 particles, silane application; (AO) Sandblasting with 50 mm Al2O3 particles, silane application. Two composite blocks were cemented to each other (n=8) and sectioned into sticks. Half of the specimens from each block were immediately tested for microtensile bond strength (µTBS), while the other half was subjected to storage for 6 months, thermocycling (12,000 cycles, between 5°C and 55°C, with a dwell time of 30 s in each bath) and µTBS test in a mechanical testing machine. Bond strength data were analyzed by repeated measures two-way ANOVA and Tukey test (α=0.05). Results The µTBS was significantly affected by surface treatment (p=0.007) and thermocycling (p=0.000). Before aging, the SP group presented higher bond strength when compared to NT and AC groups, whereas all the other groups were statistically similar. After aging, all the groups were statistically similar. SP submitted to thermocycling showed lower bond strength than SP without thermocycling. Conclusion Core composites should be roughened with a diamond bur before the luting process. Thermocycling tends to reduce the bond strength between composite and resin cement.

OBJECTIVES: Previous studies that evaluated the torque needed for removing dental implant screws have not considered the manner of transfer of the occlusal loads in clinical settings. Instead, the torque used for removal was applied directly to the screw, and most of them omitted the possibility that the hexagon could limit the action of the occlusal load in the loosening of the screws. The present study proposes a method for evaluating the screw removal torque in an anti-rotational device independent way, creating an unscrewing load transfer to the entire assembly, not only to the screw. MATERIAL AND METHODS: Twenty hexagonal abutments without the hexagon in their bases were fixed with a screw to 20 dental implants. They were divided into two groups: Group 1 used titanium screws and Group 2 used titanium screws covered with a solid lubricant. A torque of 32 Ncm was applied to the screw and then a custom-made wrench was used for rotating the abutment counterclockwise, to loosen the screw. A digital torque meter recorded the torque required to loosen the abutment. RESULTS: There was a significant difference between the means of Group 1 (38.62±6.43 Ncm) and Group 2 (48.47±5.04 Ncm), with p=0.001. CONCLUSION: This methodology was effective in comparing unscrewing torque values of the implant-abutment junction even with a limited sample size. It confirmed a previously shown significant difference between two types of screws.

INTRODUCTION: Marginal discrepancies may lead to cement washout and marginal leakage, damaging periodontal and pulp tissues or causing premature loss of the restoration. PURPOSE: This study evaluated the influence of application site of provisional cement on the marginal adaptation of provisional crowns. MATERIAL AND METHODS: Four different application sites of provisional cement (Temp Bond NE, Kerr Corporation) were used for cementation of provisional crowns on phantom teeth prepared for full crown restorations, performing 4 experimental groups (n=10): cement applied to all internal surfaces of the crown (CAO); cement applied to all internal surfaces of the crown, except for the occlusal surface (CA); cement applied to the cervical crown margin (CM); and cement applied to the cervical tooth margin (TM). A comparison microscope (Mitutoyo America Corporation) was used to measure the distances between the internal tangents of two circular marks, one made on the provisional crown and one made apical to the tooth preparation margin, in areas corresponding to buccal, lingual, mesial and distal surfaces. Marginal adaptation was determined before and after cementation, with 0.0001-mm accuracy. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. RESULTS: Mean values of marginal opening obtained for each group were: CAO: 145 µm; CA: 67 µm; CM: 46 µm; TM: 34 µm. CA, CM and TM presented significantly lower marginal openings than CAO (p<0.05). CONCLUSION: complete filling of the crown with provisional cement, including the occlusal surface, provided grater marginal discrepancies when compared to the other methods evaluated.