Digital photography vs. clinical assessment of resin composite restorations.

PURPOSE: To compare direct clinical and indirect digital photographic assessment of resin composite restorations. Ninety-two posterior resin composite restorations were classified using World Dental Federation (FDI) criteria by two different clinical examiners (C1 and C2). In the same appointment of clinical assessment, intraoral high-quality digital photographs were taken and posteriorly two different digital examiners (D1 and D2) classified the images of each restoration. Restorations of each patient were assessed once by C1 and C2 independently. D1 and D2 assessed the digital images from different locations and in different time. Data were analyzed using the Cohen's kappa coefficient, Kruskal-Wallis non-parametric test and Dunn's multiple shared test, with 95% confidence. Agreement levels varied from very good (0.81-1.00) to fair (0.21-0.40). Statistically significant differences (p < 0.05) between assessments were found for surface lustre, staining, color match and translucency, esthetic anatomical form, fracture of material and retention and marginal adaptation. The classification of the resin composite restorations varied significantly according to clinical or high-quality digital photographic assessments. Overall, clinical assessment detected more demand for repair or replacement.

Adaptation accuracy of milled lithium disilicate crowns: A 2D and 3D microCT analysis.

OBJECTIVE: Evaluate the effects of the scanning techniques and the crystallization in the internal and marginal adaptation of milled lithium disilicate crowns by two techniques computer microtomography analysis. MATERIALS AND METHODS: Sixteen polyurethane teeth prepared for a complete crown were divided into two groups according to the scanner method (n = 8): indirect (IND), dental stone models were scanned with laser-surface scanner, and direct (DIR), digital typodont creates with an intraoral scanner. Internal and marginal gap were evaluated by micro-computed tomography (microCT). The replica technique (RT) was applied for analysis of total volume (TV) and marginal volume (MV) gap in microCT. The data showed normal distribution (Shapiro-Wilk test). One-way ANOVA (scanner techniques) with repeated measures (crystallization) was performed. Multiple comparisons were performed with Bonferroni adjustment (α = .05). RESULTS: The axial gap showed a significant difference between the times (P = .017) for lower values after crystallization. The vertical marginal gap presented a significant difference in times for higher value after crystallization (P = .001). The marginal horizontal gap IND was greater than DIR after crystallization (P = .001) and IND before lower than after crystallization. For TV was not significant difference and MV in DIR was reduction (P = .002) after crystallization. CONCLUSION: Crystallization changes the relationship between the crown and tooth, reducing internal gap and preventing the adequate fit in indirect and direct scanning. CLINICAL SIGNIFICANCE: The measure gap under technological methodology is useful for adjust clinical parameters prosthetic in the CAD/CAM and the applicability of the new possibilities of analysis.

Influence of metal bar lever-arm on screws detorque for dental prosthesis implant supported / Influência do cantilever no destorque de parafusos de barras metálicas utilizadas em próteses do tipo protocolo de Brannemark

Introduction: The cantilever length of implant-supported fixed prosthesis metal structure has been considered an important factor to transfer occlusion forces to the dental implant. Objective: This study evaluated the influence of different extensions of cantilevers of Branemark protocol implant prosthesis when submitted to mechanical thermocycling by screw loosening evaluation. Material and method: The groups G10 (n = 5), G15 (n = 5) and G20 (n = 5) were formed according to the distance in millimeters between the force application site in the cantilever and the center of the last implant. All metal structures (n = 15) were submitted to a 120 N cyclic vertical load in a chewing simulation machine (MSM-Elquip, São Carlos-SP, Brazil) under controlled temperature and moisture conditions. Two hundred and fifty thousand mechanical cycles were performed with a frequency of 2 Hz that simulates a masticatory activity similar to 3 months. To compare the data obtained regarding the loosening of the metal structure screws, implant position and sites of load application, the analysis of variance with two factors and the Tukey test were performed. Result: Statistical analysis showed that the G10 group presented greater torque loss, statistically different from G15 (p = 0.001) and G20 (p = 0.002), and there was no significant difference between groups G15 and G20. Conclusion: It can be concluded from the results that all the screws presented torque loss after simulation of 3 month masticatory activity, suggesting the need for periodical evaluation to prevent failures in the treatment.

Introdução: O comprimento do cantilever da infraestrutura de prótese implanto-suportada tem sido considerado um importante fator de transferência de força de oclusão para o implante dentário. Objetivo: Esse trabalho avaliou a influência das diferentes extensões do cantilever da prótese sobre implantes tipo protocolo de Branemark submetidas à termociclagem mecânica pela avaliação dos afrouxamentos dos parafusos de fixação. Material e método: Os grupos G10 (n=5), G15 (n=5) e G20 (n=5) foram formados de acordo com a distância, em milímetros, entre o local de aplicação de força no cantilever e o centro do último implante. Todas as barras (n=15) foram submetidas a carga vertical cíclica de 120 N em uma máquina de simulação de mastigação (MSM-Elquip, São Carlos/SP, Brasil), em condições de temperatura e umidade controladas. Foram realizados 250 mil ciclos mecânicos com frequência de 2 Hz que simulou uma atividade mastigatória correspondente a 3 meses. Para comparar os dados obtidos quanto à soltura dos parafusos da barra, a posição dos implantes e os locais de aplicação de carga, foi realizada a análise de variância com dois fatores e o teste de Tukey. Resultado: A análise estatística mostrou que o grupo G10 apresentou maior perda de torque, diferente estatisticamente de G15 (p=0,001) e G20 (p=0,002) e que não houve diferença significante entre os grupos G15 e G20. Conclusão: Pode-se concluir que todos os parafusos apresentaram perda de torque após o ensaio simulando uma atividade mastigatória de 3 meses, sugerindo a necessidade de avaliação clínica periódica afim de prevenir fracasso no tratamento.

Influence of 2D vs 3D imaging and professional experience on dental implant treatment planning.

OBJECTIVES: This study investigated whether professional experience and type of image examination (panoramic radiography (PAN) or cone beam computed tomography (CBCT)) could influence the pre-surgical planning for dental implant treatment. MATERIALS AND METHODS: Six dentists, from two different levels of experience (senior (Sr) and junior (Jr)) performed simulated pre-surgical planning by using PANs and after 1 month, by using CBCTs, considering implant length (IL), implant width (IW), need for bone graft (BG), and other surgical procedures (OP). Bland-Altman test and Kappa coefficient were used to identify agreements. RESULTS: Bland-Altman test showed good agreement in the plans for inter-professional (i.e., Sr vs Jr) comparisons. Bland-Altman plots displayed intra-observer agreement (i.e., differences between PAN and CBCT), showing discrepancy between imaging modalities for IL and a tendency towards selecting larger dental implant options when using PAN and smaller options with CBCT. Kappa showed almost perfect (0.81-1.0) agreement between Jr and Sr for OP (PAN and CBCT). For BG, agreement was substantial (0.61-0.80) when planning was done with PAN and CBCT. Descriptive statistics showed evidence that when Jrs used CBCT, they no longer indicated the BG they had planned when they used PAN. CONCLUSION: There were differences in the pre-surgical planning for treatment with dental implants depending on the professional experience and the type of imaging examination used. CLINICAL RELEVANCE: Variation in dental implant planning can affect treatment time, cost, and morbidity in patients.

Evaluation of Marginal Misfit of Metal Frameworks Welded by Gas-Torch, Laser, and Tungsten Inert Gas Methods.

PURPOSE: The objective of this study was to evaluate the marginal fit and the flexural resistance of nickel-chromium frameworks welded by different techniques, gas-torch, laser, and tungsten inert gas (TIG), compared with that of frameworks made via one-piece casting. METHODS: To evaluate the marginal fit, a master model was fabricated simulating four implants. Transfers and replicas were used to transfer the positions of the implants to the model, using a silicone matrix. The bars were waxed up and casted. Three assessments of misfit were performed for each implant using a stereomicroscope before and after welding in two predetermined regions, totaling six readings for each implant. To evaluate the flexural resistance, one group was made casting the specimens in one piece. Other 3 groups using gas-torch, laser, and TIG welding techniques were made after sectioned transversally. The data showed normal distribution and two-way ANOVA for marginal fit and one-way ANOVA for flexural resistance, and Tukey's posttest (α=0.05) was performed. RESULTS: For the marginal fit, the three welding methods presented similar results and were different from one-piece casting. For the flexural resistance, significant differences were observed among the studied groups (p < 0.001), and the one-piece group presented higher resistance compared to the three welding techniques. CONCLUSIONS: Within the limits of this study, the three welding techniques yielded similar misfit results, and the laser and TIG techniques presented similar flexural resistance but lower than gas-torch and one-piece casting.

Removal of Implant and New Rehabilitation for Better Esthetics.

Tooth loss can result in loss of facial esthetics, in addition to its effect on mastication, swallowing, and speech. Adequate planning is required in order for the prosthetic treatment of the teeth and implants to be successful. Here, we present a clinical case demonstrating that improper positioning of an implant can make prosthetic rehabilitation unfeasible, necessitating new surgical and rehabilitation planning to achieve the desired esthetics. The patient had a missing right lateral incisor and cuspid, and a buccally directed implant. The preferred treatment regimen involved the removal of this implant and placement of another one more properly positioned distally and three dimensionally. The repositioning of the implant made rehabilitation treatment with a mesial cantilever possible. Due to esthetic considerations, gingival conditioning in the cantilever region was performed in the temporary prosthesis phase. The changes adopted in planning the surgery and rehabilitation resulted in good esthetics as well as functional outcomes.

Prótese parcial fixa conservadora com duplo sistema de fixação: relato de caso

Objetivo: apresentar uma alternativa conservadora de tratamento, com duplo sistema de fixação, em um caso de insucesso com prótese parcial fixa adesiva. Relato de caso: paciente do gênero feminino, 41 anos de idade, compareceu para tratamento na Faculdade de Odontologia de Ribeirão Preto com uma prótese parcial fixa adesiva, na região do dente 36, com deficiência na retenção e necessidade recorrente de fixação. No exame clínico, verificou-se desadaptação dos retentores metálicos nas faces linguais dos dentes pilares, tornando inviável a refixação da peça. Os preparos realizados nos dentes apresentavam deficiências na extensão e na ausência de apoios nas cristas marginais e paralelismo entre os dentes preparados. Como tratamento, foram realizadas restauração da morfologia dos dentes pilares com resina composta e confecção de uma prótese parcial fixa ultraconservadora, que resultou na manutenção das características de preparos com reduzido desgaste, restabelecimento da estética e da oclusão e eficácia na retenção da peça protética. Considerações finais: pode-se considerar que a prótese parcial fixa ultraconservadora, além de indicada para pequenos espaços edêntulos, com objetivo principal de preservação de estrutura dental, apresenta excelente sistema de fixação no substrato e pode ser utilizada como terapia alternativa em caso de insucesso da prótese parcial fixa adesiva.

Ultraconservative fixed partial denture: esthetic and preservation of dental structure / Prótese parcial fixa ultraconservadora: estética com preservação de estrutura dental

The oral rehabilitation can be made with several ways with the objective to reestablish the masticatory function and the esthetic of the patient. The aim of this clinical case is to present a different type of fixed partial denture, as alternative option to the dental surgeon, showing particularities like indications, contraindications, advantages, disadvantages and technical procedures necessary to its fabrication. The sequential presentation of the realized procedures emphasized the unique aspects of the dental preparation, impression techniques, and cautions during metal structures and ceramic try-in procedures, and esthetic overlay on the metal with composite resin. As a result, it could be observed that the ultraconservative fixed partial denture required lesser removal dental structure, re-established the esthetic and the occlusion of the patient. Finally, it can be concluded that the ultraconservative fixed partial denture is a treatment option to be used in the small prosthetic space with success both mechanically and esthetically.

A reabilitação oral pode ser realizada de diversas formas com o intuito de restabelecer a função mastigatória e a estética do paciente. Este caso clínico tem o objetivo de apresentar um tipo diferente de prótese parcial fixa, como opção alternativa para o cirurgião-dentista, mostrando suas particularidades quanto à indicação, contraindicação, vantagens, desvantagens e procedimentos necessários à sua elaboração. A apresentação sequencial dos procedimentos realizados ressaltou os aspectos únicos do preparo dental, da técnica de moldagem, dos cuidados a serem observados na prova da estrutura metálica, na prova da cerâmica, dos aspectos diferenciais na cimentação e do recobrimento estético da estrutura metálica com resina composta. Como resultado pode-se observar que a prótese ultraconservadora exigiu menor desgaste estrutural dos dentes pilares, restabeleceu a estética e a oclusão do indivíduo. Diante disso, pode-se concluir que a prótese parcial fixa ultraconservadora é uma opção de tratamento a ser utilizada em pequenos espaços protéticos com sucesso mecânico e estético.

Avaliação da resistência flexural entre diferentes métodos de soldagem / Evaluation of flexural strength among different welding methods

A técnica de soldagem, muito utilizada em prótese parcial fixa, permite a união das partes metálicas, favorecendo a adaptação da prótese e a distribuição das forças mastigatórias, minimizando falhas no tratamento reabilitador. O objetivo deste trabalho foi avaliar a resistência flexural dos métodos de soldagem com chama direta, laser e TIG, utilizando uma liga de NiCr. Um grupo controle (M) foi confeccionado fundindo os corpos de prova em monobloco. Foram confeccionados três grupos: chama direta (C), laser (L) e TIG (T), onde os corpos de prova foram seccionados transversalmente. Em razão das características das soldagens laser e TIG que ocorrem apenas perifericamente, foram realizados outros dois grupos: laser (L1) e TIG (T1), em que os corpos de prova foram seccionados em chanfro de 45º. Os corpos de prova tiveram suas extremidades unidas com resina duralay e cada grupo passou pelo seu respectivo processo de soldagem, torneamento, simulação de cocção da porcelana e, finalmente, submetidos aos testes de flexão. Os valores numéricos registrados foram de 1,79 GPa (M), 1,37 GPa (C), 0,99 GPa (T), 1,26 GPa (T1), 1,03 GPa (L) e 1,09 GPa (L1). Os dados obtidos foram submetidos à análise estatística (Anova – p < 0,5). Concluiu-se que todos os grupos laser e TIG apresentaram resultados semelhantes entre si; os grupos laser e TIG com preenchimento foram semelhantes ao grupo chama e todos os grupos soldados foram diferentes estatisticamente do grupo controle.

Soldering methods used to join fixed partial dentures favor prosthesis fit and distribution of masticatory forces, minimizing failures in the oral rehabilitation process. The aim of this work was to evaluate the flexural strength of different soldering methods as brazing, TIG, and laser welding using a Ni-Cr alloy. A control group (M) was made using one-piece castings. Also, other three groups were made by brazing (C), TIG (T), and laser (L) being sectioned in a transversal direction. Another two groups were ssectioned in a 45-degree chanfer configuration. The specimens were joined with acrylic resin and submitted to flexural tests. The numerical values were 1,79 GPa (M), 1,37 GPa (C), 0,99 GPa (T), 1,26 GPa (T1), 1,03 GPa (L) e 1,09 GPa (L1). The Anova test (p=0.05) was performed to identify possible significant differences among groups. The conclusions were: all Laser and TIG groups were statistically similar with the brazing group and all the experimental groups were statistically different from the control group.

Reestablishment of occlusion through overlay removable partial dentures: a case report.

Loss of posterior teeth may cause an imbalance in the stomatognathic system. Overlay removable partial dentures (ORPD) are a reversible and relatively inexpensive treatment for patients with severely worn teeth. This paper presents a treatment with ORPD in a 55-year-old male patient who had severe attrition in the maxillary and mandibular teeth, temporomandibular joint pain and reduced vertical dimension of occlusion (VDO). The treatment consisted in the reestablishment of the VDO using Lucia's jig, fabricating removable partial denture with reconstruction of the worn teeth without preparation. This therapy can be used as an alternative treatment to provide esthetic, function and stable occlusion in patients with severely worn teeth.

Reestablishment of occlusion through overlay removable partial dentures: a case report

Loss of posterior teeth may cause an imbalance in the stomatognathic system. Overlay removable partial dentures (ORPD) are a reversible and relatively inexpensive treatment for patients with severely worn teeth. This paper presents a treatment with ORPD in a 55-year-old male patient who had severe attrition in the maxillary and mandibular teeth, temporomandibular joint pain and reduced vertical dimension of occlusion (VDO). The treatment consisted in the reestablishment of the VDO using Lucia’s jig, fabricating removable partial denture with reconstruction of the worn teeth without preparation. This therapy can be used as an alternative treatment to provide esthetic, function and stable occlusion in patients with severely worn teeth.

A perda de dentes posteriores pode provocar o desequilíbrio do sistema estomatognático. As próteses parciais removíveis terapêuticas atuam como terapia reversível e não dispendiosa para os pacientes com desgastes dentais severos. Este trabalho apresenta um tratamento com as próteses parciais removíveis terapêuticas (overlay) em um paciente de 55 anos, do gênero masculino que apresentava atrição severa nos dentes superiores e inferiores, dor na articulação temporomandibular e dimensão vertical de oclusão reduzida. O tratamento consistiu em restabelecer a dimensão vertical de oclusão utilizando o Jig de Lucia, próteses parciais removíveis com reconstrução dos dentes desgastados e sem preparos. Esta terapia pode ser utilizada como uma alternativa de tratamento para a obtenção de estética, função e estabilidade oclusal em pacientes com desgastes dentais severos.

Pilar sobre implante em zircônia: relato de caso clínico / Zirconia implant abutment: a case report

A Odontologia Estética trouxe para a realidade do consultório odontológico atual a mimetização das nuances de cor, texturas e características ópticas para reabilitações realizadas em porcelana. Para que este fato ocorra, é necessário que uma boa parte das características estruturais de um dente natural seja reproduzida. O esmalte dental é reproduzido com sucesso satisfatório através da utilização de técnicas inovadoras e porcelanas de qualidade avançada. A dentina também deve ser reproduzida, e para que isso seja possível em reabilitações sobre implantes surgiu a possibilidade de serem confeccionados pilares em porcelana pura do tipo zircônia. São pilares instituídos com a proposta de oferecer resistência mecânica satisfatória à sustentação de coroas sobre implantes, além da condição estética. Desta forma, descreveu-se o caso clínico que visou a utilização de um implante imediato ativado imediatamente com a utilização de um provisório sobre o implante posicionado na região do dente 22 de uma paciente de 33 anos. Como o objetivo principal do caso foi atingir excelência em estética, optou-se pela utilização de um pilar de zircônia (CONEXÃO@) sobre o implante colocado. Verificou-se, além de benefícios estéticos, saúde gengival na área implantada, pois a zircônia possui biocompatibilidade e filia aos tecidos vivos quando comparada a pilares sobre implantes confeccionados em metal. O caso clínico vem sendo acompanhado com proservação de 7 anos. Conclui-se que a opção da utilização dos novos pilares em zircônia traz para os casos de reabilitação sobre implantes uma resolução mais interessante para os anseios estéticos e funcionais dos pacientes da atualidade.

Esthetic Dentistry has brought the reality of current dental mimicking the nuances of color,texture and optical properties for renovations carried out in porcelain. So that this does occur, it is necessary for a good part of the structural characteristics of a natural tooth to be played. The enamel is successfully reproduced satisfactorily by the use of innovative techniques and advanced quality porcelain. Dentin also be reproduced, and for this to be possible in rehabilitation on implants arose the possibility of pillars made of porcelain-type pure zirconia. Pillars are set up with the proposal to provide satisfactory mechanical strength to the support of crowns on implants in addition to the aesthetic condition. Thus, described the case history which endorsed the use of an implant immediately activated immediately by using a duty on the implant positioned in the region of tooth 22, a patient of 33 years. As the main objective of the case was achieved excellence in aesthetics, it was decided to use a pillar of zirconia (CONEXÃO SISTEMA DE PRÓTESE@) on the implant placed. It was found, and aesthetic benefits, gingival health in the area because the implanted zirconia has biocompatibility and affiliated to the living tissue quite satisfactory when compared to pillars on implants ma de of metal, and it was proved with preservation of 7 years. We conclude that the option of using new pillars in zirconia brings to the cases of rehabilitation on implants a resolution much more interesting for the aesthetic and functional desires of patients.

Pré-molarização: uma alternativa para reabilitações implantossuportadas em região posterior / Premolarization: an alternative to implant-supported rehabilitations in the posterior region

Diferenças anatômicas e biomecânicas fazem do tratamento com implantes em regiões posteriores substancialmente diferentes daquele em região anterior. Sem os implantes e diante da perda de dentes posteriores, as opções de tratamento incluem próteses parciais fixas extensas ou próteses parciais removíveis, especialmente quando não há um pilar distal disponível. Contemporaneamente, as próteses implantossuportadas representam um tratamento altamente eficaz e aceitável para a reabilitação oral de indivíduos parcialmente edêntulos, entretanto, tornou-se necessário reavaliar e modificar alguns conceitos previamente estabelecidos devido aos impactos negativos proporcionados por modelos de próteses nos quadrantes posteriores, como o desfavorável perfil de emergência, dificultando o controle de placa bacteriana, a impacção alimentar e a dissipação não axial das forças oclusais. Modificando-se o planejamento dessas próteses, onde coroas de molares sejam substituídas por coroas de pré-molares, proporciona-se uma possível solução para esses problemas. Assim, três pré-molares podem equivalentemente substituir dois molares, situação esta que caracteriza o conceito de pré-molarização. O objetivo do presente estudo foi relacionar os aspectos funcionais e biomecânicos envolvidos nas próteses implantossuportadas em regiões posteriores, estabelecendo-se assim as possíveis vantagens da aplicação da pré-molarização nas reabilitações orais sobreimplantes.

mplant treatment in posterior regions is substantially different, both anatomical and biomechanically, from the anterior regions. Without considering dental implants, and with the loss of posterior teeth, treatment options include an extensive fixed or removable partial denture, especially when no distal tooth abutments are available. Nowadays, the implant-supported dental prosthesis represent a highly effective and acceptable treatment for oral rehabilitation of partially edentulous individuals, however, it became necessary to reevaluate and modify some of the concepts previously established due to the negative impacts provided by prosthesis models in the posterior regions, as the unfavorable emergence profile, making it difficult to control plaque, food impaction and non-axial dissipation of the occlusal forces. By modifying prosthesis design, where molar crowns are replaced by premolars crowns, a possible solution is offered. Thus, three premolars can equivalently replace two molars, a situation that characterizes the concept of premolarization. The aim of this study was to compare the biomechanical and functional aspects involved in implant-supported dental prosthesis for posterior regions, thus establishing the potential benefits of applying the premolarization concept to the implant-supported oral rehabilitation.

Effect of temporary cements on the shear bond strength of luting cements.

OBJECTIVE: The purpose of this study was to evaluate, by shear bond strength (SBS) testing, the influence of different types of temporary cements on the final cementation using conventional and self-etching resin-based luting cements. MATERIAL AND METHODS: Forty human teeth divided in two halves were assigned to 8 groups (n=10): I and V (no temporary cementation); II and VI: Ca(OH)2-based cement; III and VII: zinc oxide (ZO)-based cement; IV and VIII: ZO-eugenol (ZOE)-based cement. Final cementation was done with RelyX ARC cement (groups I to IV) and RelyX Unicem cement (groups V to VIII). Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. RESULTS: Means were (MPa): I - 3.80 (+/-1.481); II - 5.24 (+/-2.297); III - 6.98 (+/-1.885); IV - 6.54 (+/-1.459); V - 5.22 (+/-2.465); VI - 4.48 (+/-1.705); VII - 6.29 (+/-2.280); VIII - 2.47 (+/-2.076). Comparison of the groups that had the same temporary cementation (Groups II and VI; III and VII; IV and VIII) showed statistically significant difference (p<0.001) only between Groups IV and VIII, in which ZOE-based cements were used. The use of either Ca(OH)2-based (Groups II and VI) or ZO-based (Groups III and VII) cements showed no statistically significant difference (p>0.05) for the different luting cements (RelyX ARC and RelyX Unicem). The groups that had no temporary cementation (Groups I and V) did not differ significantly from each other either (p>0.05). CONCLUSION: When temporary cementation was done with ZO- or ZOE-based cements and final cementation was done with RelyX ARC, there was an increase in the SBS compared to the control. In the groups cemented with RelyX Unicem, however, the use of a ZOE-based temporary cement affected negatively the SBS of the luting agent used for final cementation.

Effect of temporary cements on the shear bond strength of luting cements

OBJECTIVE: The purpose of this study was to evaluate, by shear bond strength (SBS) testing, the influence of different types of temporary cements on the final cementation using conventional and self-etching resin-based luting cements. Material and Methods: Forty human teeth divided in two halves were assigned to 8 groups (n=10): I and V (no temporary cementation); II and VI: Ca(OH)2-based cement; III and VII: zinc oxide (ZO)-based cement; IV and VIII: ZO-eugenol (ZOE)-based cement. Final cementation was done with RelyX ARC cement (groups I to IV) and RelyX Unicem cement (groups V to VIII). Data were analyzed statistically by ANOVA and Tukey's test at 5 percent significance level. RESULTS: Means were (MPa): I - 3.80 (±1.481); II - 5.24 (±2.297); III - 6.98 (±1.885); IV - 6.54 (±1.459); V - 5.22 (±2.465); VI - 4.48 (±1.705); VII - 6.29 (±2.280); VIII - 2.47 (±2.076). Comparison of the groups that had the same temporary cementation (Groups II and VI; III and VII; IV and VIII) showed statistically significant difference (p<0.001) only between Groups IV and VIII, in which ZOE-based cements were used. The use of either Ca(OH)2-based (Groups II and VI) or ZO-based (Groups III and VII) cements showed no statistically significant difference (p>0.05) for the different luting cements (RelyX TM ARC and RelyX TM Unicem). The groups that had no temporary cementation (Groups I and V) did not differ significantly from each other either (p>0.05). CONCLUSION: When temporary cementation was done with ZO- or ZOE-based cements and final cementation was done with RelyX ARC, there was an increase in the SBS compared to the control. In the groups cemented with RelyX Unicem, however, the use of a ZOE-based temporary cement affected negatively the SBS of the luting agent used for final cementation.

Using overdenture on implants and complete dentures: effects on postural maintenance of masticatory musculature

Aims: Thanks to advances in osseointegration, oral rehabilitation specialists have had the option of using implants to improve retention and stability in treatments with complete dentures. This study compared the masticatory muscle electromyographic activity in implant-supported overdenture wearers, complete denture wearers and dentate individuals. The electromyographic activity of the right and left masseter muscles, and the right and left anterior temporalis muscles was analyzed in 10 implant-supported overdenture wearers (Group 1), 10 conventional complete denture wearers (Group 2), and 10 dentate individuals (Group 3), with mean age of 65 years, at rest and during postural position maintenance. The analysis was performed using the MyoSystem-Br1 electromyographer with differential active electrodes. Analysis of variance tests were carried out to compare the groups and muscles and revealed different electromyographic values that were statistically significant at 1% significance level. Duncan’s pos-hoc test showed that Group 3 presented the smallest values (pd”0.01). The electromyographic contraction pattern was similar between Groups 1 and 3 (p>0.01), and hyperactivity of anterior temporalis muscles was observed in Group 2 (pd”0.01). Conclusions: dentate individuals had smaller electromyographic values of masticatory muscles and the overdenture use caused electromyographic contraction patterns similar to those of dentate individuals in both positions.

Diferentes métodos de avaliação do nível de contaminação microbiana da água de alta rotação / Diferent methodos of evaluation of microbiak contamination level of high-speed

A água do equipo odontológico que resfria os equipamentos giratórios/rotatórios de alta velocidade, como os de alta rotação, pode apresentar número elevado de microrganismos. Assim, os aerossóis formados são fonte de risco de disseminação/contaminação na odontologia. O objetivo desta pesquisa foi avaliar e comparar o nível de bactérias aeróbias mesófilas totais presentes em amostras de água de alta rotação (AR), de 10 equipos odontológicos da Faculdade de Odontologia de Ribeirão Preto - USP, por meio do método tradicional/convencional pour plate e o método rápido Petrifilm AC (3M, St Paul, MN, USA). Cerca de 10,0ml das amostras de água foram coletadas dos AR sem as peças de mão, em tubos de ensaio (25x125mm). As amostras foram homogeneizadas, diluídas, semeadas e incubadas. Todas as amostras de água dos AR estavam altamente contaminadas, não havendo diferença estatisticamente significante (p>0,05) entre o nível de contaminação encontrado pelo método tradicional, comparado com o método rápido. Em conclusão, o método rápido Petrifilm foi considerado mais prático que o tradicional, e totalmente adequado para monitorar a contaminação microbiana das águas dos AR que estavam acima do recomendado pela American Dental Association(<200UFC/ml) e do permitido pela legislação brasileira (<500UFC/ml). Então, para a melhoria da qualidade microbiológica da água de equipos odontológicos, as sugestões dos autores desse trabalho deveriam ser acatadas pelos profissionais da odontologia

Dental units have cold water that supplies gyration/rotation equipments of high-speed, such as highspeedhandpieces, may have a high number of microorganisms. Therefore, aerosol formation is a risksource of microbial dissemination/contamination in dentistry. The aim of this research was to evaluateand compare total aerobic bacteria contamination level in high-speed (HS) water from 10 dental units atFaculty of Dentistry of Ribeirão Preto - USP using a traditional method, pour plate and a fast method, PetrifilmTM AC (3M, St Paul, MN, USA). Approximately 10.0ml of dental unit water were collected from HS, without handpieces, in tubes (25x125mm). The samples were homogenized, diluted, inoculated and incubated. All HS water samples were highly contaminated, no having statistical difference (p>0.05)between contamination level got traditional and fast method. In conclusion, the fast method PetrifilmTM was considered more useful than traditional method, and totally acceptable to monitor the microbial contamination in water from HS that was higher than American Dental Association's recommendation (<200CFU/ml) and allowed for Brazilian legislation (<500CFU/ml). Thus, to improve the water microbiology quality from dental units, the authors´ suggestions this work should be followed by dental professionals

Reabilitação de mandíbula edêntula utilizando a técnica de "Tent Pole" / Rehabilitation of the mandible using the Tent Pole technique

A reabilitação protética de mandíbulas edêntulas muitas vezes torna-se insatisfatória em função da falta de tecido de suporte para utilização de prótese. A falta de estabilidade protética ocasiona perda de qualidade de vida, pois geralmente resulta em limitação funcional e social além de trauma físico crônico. Além disso, a perda de tecido de suporte pode predispor a mandíbula a fraturas espontâneas. Várias técnicas de reconstrução para mandíbulas edêntulas severamente reabsorvidas são relatadas na literatura, todas com suas vantagens e desvantagens. Este artigo descreve um caso clínico onde a reabilitação mandibular foi realizada com prótese fixa do tipo protocolo Branemark, após cirurgia pré-protética reconstrutora com a utilização de enxerto ósseo autógeno e implantes osseointegráveis pela técnica "Tent Pole".

The prosthetic rehabilitation of an atrophic mandible usually is unsatisfactory due the lack of the support tissues including bone and keratinized mucosa. The prosthetic instability leads a social and functional limitation and chronic physical trauma decreasing the patient's life quality. ln accentuated degrees of atrophy the placement of osseous-integrated implants can expose the mandible to spontaneous fracture in the literature many preprosthetic reconstructive surgeries techniques were proposed for atrophic mandible rehabilitation each one with their advantages and disadvantages. ln this article the authors present a case where an atrophic mandible was rehabilitated following the Brememark protocol after preprosthetic reconstructive surgery by "Tent Pole" technique.

Prótese total com dentes desgastados x disfunção temporomandibular: relato de caso / Complete dentures with worn teeth x temporomandibular dysfunction: a case report

A presença de disfunção temporomandibular em portadores de prótese total tem sido descrita com freqüência. Sua etiologia multifatorial envolve fatores emocionais e alterações no sistema estomatognático em função da prótese. Hábitos parafuncionais, assim como o desgaste de dentes e relações maxilo-mandibulares incorretas têm sido considerados fatores importantes e que precisam receber especial atenção pelo profissional. A solução destas alterações pode ser obtida por meio de aparelhos removíveis ou adição de resina à prótese existente, mas como no caso clínico descrito, antes da confecção de novas próteses, é fundamental que o restabelecimento da dimensão vertical de oclusão seja feita de forma criteriosa e que o paciente seja observado por um período de tempo para a certificação de sua adaptação à nova dimensão.

Núcleos metálicos fundidos x pinos pré-fabricados / Cast metal posts x pre-fabricated posts

A restauração de um dente tratado endodonticamente, com ampla destruição coronária, tem se constituído em um desafio para clínicos e pesquisadores. Os núcleos metálicos fundidos são, há mais de cem anos, a solução mais empregada para recuperação destes dentes. Com o surgimento dos núcleos pré-fabricados, que tem baixo custo, facilidade de técnica e são mais estéticos, os núcleos metálicos fundidos estão sendo menos utiizados. O objetivo deste trabalho foi revisar a literatura a respeito dos vários tipos de pinos pré-fabricados, comparando-os com os tradicionais núcleos metálicos fundidos. Concluiu-se que ainda não existe um pino pré-fabricado com material e técnica que supra todos os casos e substitua em definitivo os núcleos metálicos fundidos