Search

This study evaluated the effect of clinical and patient-related factors on marginal bone loss. The sample was composed of individuals who were treated at two dental schools in southern Brazil. The variables evaluated were divided into individual (age, sex, diabetes, hypertension and antihypertensive use), and implant levels (arch, position, brand, protection, torque, time). After implant installation and following the second stage, periapical radiographs were obtained to measure the distance between the peri-implant bone crest and implant platform. Measurements were performed using ImageJ software. Data were analyzed using linear and Poisson multilevel regression. Fifty-eight patients with 113 implants were evaluated. The mean marginal bone loss was 0.45 ± 0.48 mm. Considering the linear multivariate model, age, diabetes, torque and time between surgery and reopening were found to be significant (p < 0.05). In the dichotomous model (bone loss

Objective: to compare the image quality obtained by six cameras used for dental documentation, including four DSLR cameras and two smartphones with different sensor size. Methods: the equipment determined the groups: APSCcan18-55 – Sensor APS-C Canon (EOS T5i) + 18-55 mm lens; APSCcan100 – Sensor APS-C Canon (EOS T5i) + 100 mm macro lens; APSCnik18-55 – Sensor APS-C Nikon (D5100) + 18-55 mm lens; APSCnik100 – Sensor APS-C Nikon (D5100) + 100 mm macro lens; ip1/3” – iPhone with 1/3-inch sensor; ga1/2.6”- Galaxy with 1/2.6-inch sensor. Two set of images -“dental documentation” and “small objects”- were obtained. The photographs were evaluated by three groups: US, undergraduate students; DS, dentists; and DP, dentists with photography experience. Scores between 0 and 10 were assigned. The results were compared by RM Anova and Tukey (α = 0.05). Results: the highest overall scores were obtained with APSCnik100 (8.5). For “dental documentation”, APSCcan18-55 and APSCnik18-55 showed the lowest values, even compared to ga1/2.6” (for US, DS and DP evaluators) and ip1/3” (for US evaluators). For “small objects”, DSLRs resulted in higher mean values compared to smartphones for US and DS. Conclusions: DSLR cameras with 18-55 mm lens and no circular flash should not be used for documentation photographs. DSLR cameras, regardless of lens, are superior to smartphones for small objects photographs.

Conventional flexural strength tests of restorative materials neglect the effect of essential variables that can affect their mechanical behavior. The purpose of this study was to evaluate the effect of cementation on the mechanical behavior of a nanoceramic resin. A nanoceramic resin (LU) and a leucite-reinforced glass-ceramic (IE) were evaluated. Non-cemented specimens of the materials were produced and subjected to biaxial flexural strength test ( σ f , n = 30 ). Cemented specimens were constituted of the restorative material bonded with resin cement onto a dentin analog substrate. Cemented specimens were subjected to the monotonic compressive load test ( L f , n = 20 ). Vickers microhardness (HV) and translucency parameter (TP) of the materials were characterized. Data were analyzed using t-test (σf and TP), Mann-Whitney test (Lf and HV), and Weibull analysis (σf and Lf, α = 0 . 05). Non-cemented LU showed higher σf and Weibull modulus (m) than IE. When cemented to the substrate, LU showed higher Lf than IE; however, the m-value was similar among groups. LU showed lower HV than IE and higher TP values. Cementation influenced the mechanical behavior and failure mode of the nanoceramic resin. Resumo Os testes convencionais de resistência à flexão de materiais restauradores negligenciam o efeito de variáveis essenciais que podem afetar seu comportamento mecânico. O objetivo deste estudo foi avaliar o efeito da cimentação no comportamento mecânico de uma resina nanocerâmica. Foram avaliadas uma resina nanocerâmica (LU) e uma vitrocerâmica reforçada por leucita (IE). Foram produzidos corpos de prova (CP) não cimentados dos materiais e submetidos ao teste de resistência à flexão biaxial ( σ f , n = 30 ). CPs cimentados foram constituídos pelo material restaurador cimentado adesivamente a um substrato análogo à dentina. Os CPs cimentados foram submetidos ao teste de carga compressiva monotônica ( L f , n = 20 ). A microdureza Vickers (HV) e o parâmetro de translucidez (TP) dos materiais foram caracterizados. Os dados foram analisados pelo teste t (σf e TP), teste de Mann-Whitney (Lf e HV) e análise de Weibull (σf e Lf, α = 0 . 05). A LU não cimentada apresentou σf e módulo de Weibull (m) superiores a IE. Quando cimentada ao substrato, a LU apresentou maior Lf que a IE; no entanto, o valor de m foi semelhante entre os grupos. A LU apresentou menor HV que a IE e maiores valores de TP. Concluiu-se que a cimentação influenciou o comportamento mecânico e modo de falha da resina nanocerâmica.

O bjective: This study evaluated the effect of drying times of two total-etch & rinse adhesives on the resin bond strength to a feldsphatic ceramic, before and after aging. Material and Methods: Feldsphatic-ceramic CAD-CAM bars were cut into blocks (12×10×4 mm) with a cutting machine (N = 32). Impressions were made of each ceramic block with silicone putty material and the negative space was filled with a composite resin. The bonding ceramic surface was etched with hydrofluoric acid, silanized, and the adhesive system (SB- Single Bond 2, 3M-ESPE; or PB- Prime & Bond NT, Dentsply) was applied. The samples were dried at different times (5, 10 and 15 s) before the cementation. The resin and ceramic blocks were cemented by a dual cure resin cement. All samples were stored in distilled water at 37 °C for 24 h. For the μ-TBS test, the samples were sliced into microbars. Half of the bars of each block was tested after 24 h and, the other bars were submitted to thermocycling (12,000×) and water storage (150 d) . For the 24 h groups, the longer drying time increased (p < 0.05) the bond strength of SB (water/alcohol adhesive), while reduced (p < 0.05) for the PB group (acetone based adhesive). Results: For the aged groups, the bond strength for the different drying times had no significant difference, for the both adhesives. Conclusion: Longer drying times increased the bond strength values of SB. Smaller drying times increased the bond strength values of PB. The aging protocol influenced the bond strength of SB groups. Keywords: Microtensile; Adhesion; Feldspar ceramic; Drying time; Adhesive system.

Objectives To compare the lifetime of Y-TZP/porcelain crowns under three different load conditions using step-stress accelerated lifetime testing. Methods The Y-TZP frameworks were milled using CAD/CAM, veneered with a porcelain and cemented onto dentine analogue dies. Specimens were divided according to the occlusal load condition ( n = 20): central fossa load (CFL), cusp tip load (CTL) and sliding contact (SC). For CFL and CTL, the cyclic load was applied parallel to the long axis of the preparation using a ceramic piston. For SC, the axial load was associated to 1 mm lateral displacement at the disto-lingual cusp. Different stress profiles were used. Failures were detected with an acoustic system. A Weibull distribution (95% confidence boundary) was used to analyse the data, and fractographic principles were used to evaluate fractured specimens. Results The acoustic monitor was able to detect the initial crack. The probability of failure (at 300 N load and 200,000 cycles) was statistically greater for CTL (0.63; 0.44–0.81) compared to CFL (0.23; 0.12–0.43). The Weibull modulus of CFL (2.1; 1.5–3.6) was greater than for SC (0.7; 0.5–1.2), with no difference in the lifetime. All specimens failed by chipping, which originated predominantly at the contact (66.7%) on CTL, and in the bulk of the porcelain on CFL (100%) and SC (80%). Conclusions Contact at the cusp tip is more harmful than at the central fossa. Data from sliding contact are less consistent than from axial contacts, but more clinically relevant. Clinical significance The loading condition of Y-TZP/porcelain crowns can influence on the probability of failure and failure mode. The contact at the cusp tip is more harmful than at the central fossa, where the stress is better distributed. Sliding contact is a better simulator of the chewing cycle compared to axial contacts.

Objetivo: Avaliar a influência da manipulação de uma resina composta (RC) com diferentes luvas na sua resistência adesiva à dentina. Metodologia: 25 terceiros molares hígidos foram seccionados 2 mm abaixo do sulco central, expondo a dentina (D). A D foi condicionada com ácido fosfórico 35%, lavada, e o sistema adesivo Single Bond Universal (3M ESPE) foi aplicado. Os dentes foram distribuídos aleatoriamente em 5 grupos, de acordo com o tipo da manipulação da RC: C (controle)- RC inserida diretamente do tubo para a D; LL- RC manipulada com luvas de látex antes da inserção; LV- RC manipulada com luvas de vinil; LC- RC manipulada com luvas de látex contaminadas; VC- RC manipulada com luvas de vinil contaminadas. Após, o conjunto foi seccionado em uma máquina de corte para a obtenção dos palitos com área aproximada de 1 mm², que foram armazenados em água destilada a 37°C por 6 meses. O teste foi realizado em uma máquina de ensaio (EMIC), com velocidade de 0,5 mm/min. Os valores de resistência adesiva foram calculados (MPa) e comparados com ANOVA, Tukey (α=0,05) e Weibull. Resultados: O grupo com maior resistência adesiva foi o LV (38,74 ± 3,63 MPa), estat Método: Foi aplicado questionário a 164 docentes do ensino fundamental do Município de Almirante Tamandaré/PR, do período vespertino, para avaliação do nível de conhecimento sobre as atitudes no pronto-atendimento a crianças em caso de TAD. Os professores responderam ao QTDA (Questionário sobre o pronto atendimento ao traumatismo alvéolo dentário), que continham 10 (dez) perguntas de múltipla escolha. O questionário contém questões sobre a atitude a ser tomada em caso de traumatismo na dentição decídua (n = 5) e na dentição permanente (n = 5), sendo estas referentes a situações de avulsão, intrusão, extrusão e fratura dentária. Cada pergunta continha de 4 a 5 opções de resposta, sendo possível, ao respondente, descrever outra atitude, caso não considerasse nenhuma das alternativas como correta. O QTDA foi respondido em dois momentos, um anterior a leitura de folheto educativo (QTDA1) e outro posterior a sua leitura (QTDA2). Resultado: Observou-se que 43,20% dos docentes não tinham conhecimento sobre os procedimentos corretos a serem adotados numa situação de TAD. Após a leitura do panfleto educativo, a taxa de acerto aumentou cerca de 21,83%, ou seja, houve diferença estatisticamente significante (p≤0,001) entre os escores antes e depois da leitura do panfleto, o que reflete uma melhora no nível de conhecimento por parte dos respondentes. Conclusão: O folheto educativo mostrou-se eficiente na aquisição de conhecimento sobre o tema TAD, resultando num percentual significativamente positivo após a leitura do folheto educativo, sendo método barato e, os educadores fazem a leitura onde e quando achar conveniente.

Objectives: The aim of this study was to evaluateby electromyography the activity of the temporalisand masseter muscles in removable partial dentures(RPDs) users, before and after new RPDs installation.Material and Methods: Ten patients were selectedfor this study. All subjects were edentulous in theposterior mandibular region (Kennedy class I orII), fully dentate in the antagonist arch, and dentalprosthesis users, which needed to be replaced. Theelectromyographic activity (EMG) recorded thesuperficial masseter and temporalis muscles, duringthe maximum voluntary bite force and the restposition. Maximum mouth opening was also verified.The measurements were recorded at four specifictimes: using the old prosthesis (T0), right after thenew prosthesis installation (T1), two weeks (T2) andfour weeks (T4) after installing the new prosthesis.All the RPDs were made by an experienced dentistand the same laboratory. Data were statisticallyanalyzed by ANOVA and Tukey tests (? = 0.05).Results: EMG values had high standard deviation atthe time T0. Generally, the mean values decreasedafter new prosthesis installation, especially aftertwo weeks from the installation (T2). During therest position, the left masseter and left temporalismuscles showed statistically significant gradualdecrease in their activities over time. Conclusion:New prostheses have positive effect on the patient’smuscular activity. However, an adaptation period ofthe muscle fibers to the new prosthesis is needed.KeywordsElectromyographic activity; Dental occlusion; Masseter; Removable partial dentures; Temporalis.

Objective: To report two cases of low level laser therapy used in the treatment of muscle pain caused by temporomandibular disorders (TMDs). Methods: Two patients of the São José dos Campos Dental School (UNESP) were selected and subjected to eight applications of low level laser therapy (diode). Laser was punctually applied on masseter and temporalis muscles bilaterally. Three methods were used to evaluate the effectiveness of treatment: pressure algometer, visual analog scale (VAS) and maximal mouth opening. Each measure was performed before and after the laser therapy session. The results were subjected to statistical analysis (ANOVA two factors and Tukey's test, ? = 0.05). Results: For both patients, no significant difference was found between the results obtained by algometer before and after laser application within each session. Nonetheless, VAS showed a tendency to lower values after laser application. The highest values obtained by the pressure algometer were found between days 9 (fourth application) and 16 (sixth application), in both cases. Both patients had an improvement in mouth opening. Conclusions: The assessment methods used were quite practical to register the pain before and after treatment. Therapy with low level laser seems to have a beneficial effect for muscle pain of temporomandibular joint (TMJ).

O objetivo do estudo foi verificar o comportamento de fratura de corpos-de-prova (CP) cerâmicos submetidos a dois métodos de ensaio mecânico, flexão biaxial e carga compressiva monotônica. Foram confeccionados 200 CP cerâmicos (120 cimentados e 80 não cimentados), em 4 configurações: CAD-on (e.max ZirCAD + Crystall/Connect + e.max CAD) YLD (e.max ZirCAD + e.max Ceram) LDC monolítico (e.max CAD) YZW monolítico (Zenostar). Os CP (n30) foram cimentados (Multilink N, Ivoclar) em bases de resina epóxica (G10) e submetidos à carga compressiva monotônica (EMIC) com velocidade de 0,5 mm/min, em água destilada (37ºC), o restante dos CP (n20) foram submetidos a flexão biaxial. As falhas foram avaliadas usando princípios de fractografia e transiluminação. Os dados foram analisados por Kurskal-Wallis e teste de Dunn´s que mostraram diferença estatística entre os grupos experimentais (p

Made available in DSpace on 2018-12-11T17:26:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-01-01 The aim of the present study is to investigate the effect of aging type (thermocycling vs. water storage) and aged unit (block vs. stick) on the repair strength of resin composite to feldspathic porcelain in testing microtensile bond strength (TBS). Ceramic specimens (N = 30) (10 × 5.7 × 4.5 mm3, Vita Mark II, Vita) were obtained from CAD-CAM blocks. One surface was etched with 10% HF and silanized. An adhesive was applied and resin composite blocks were constructed incrementally on the conditioned surface. The specimens were randomly divided into five groups (n = 6): Control (C): Non-aged; BTC: Blocks were thermocycled (5-55 °C, 6000 cycles); STC: Sticks were thermocycled; BS: Blocks aged in water storage (6 months) after themocycling; SS: Blocks aged in water storage (6 months) after thermocycling. After TBS test, failure types were classified. Data (MPa) were statistically analyzed (1-way and Dunett and 2-way ANOVA, Tukey's) (α = 0.05). Two-parameter Weibull distribution values including the Weibull modulus, scale (m), and shape (0) values were calculated. Aging type (p = 0.009) and aged unit (p = 0.000) significantly affected the results. Interaction terms were also significant (p = 0.000). Considering the stick level, there was no significant difference between thermocycling (STC: 25.7 ± 2.3) and water storage (SS: 25.3 ± 3.8) (p > 0.05) but the results were significantly higher when blocks were thermocycled (BTC: 31.6 ± 2.9) (p < 0.05). Weibull modulus and characteristic strength was the highest in BTC (m = 4.2; σo: 34.4) among all other groups (m = 3-3.9; σo: 14.6-28.5). Adhesive failures were common and cohesive failures occurred in less than 5% in all groups. Aging protocol was detrimental on durability of repair strength of resin composite to feldspathic porcelain. Exposing the sticks to either thermocycling or water storage aging should be considered in in vitro studies. Post-graduation Program in Dentistry Dental School University of Passo Fundo Department of Dental Materials and Prosthodontics Institute of Science and Technology Sao Paulo State University (UNESP) Department of Dentistry Federal University of Rio Grande Do Norte/UFRN Clinic for Fixed and Removable Prosthodontics and Dental Materials Science Center for Dental and Oral Medicine Dental Materials Unit University of Zurich Department of Dental Materials and Prosthodontics Institute of Science and Technology Sao Paulo State University (UNESP)

Made available in DSpace on 2018-12-11T16:58:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-08-10 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Purpose This study aimed to evaluate the effect of heat treatment (at 77 °C) of a silanized feldspathic ceramic on microtensile bond strength (μTBS) with a resin cement before and after being aged by thermocycling. Material and methods Twenty-four blocks (12×10×4 mm3) of a CAD/CAM feldspathic ceramic (Vitablocks Mark II, Vita) were obtained and randomly divided into three groups, according to the surface treatment prior to the cementation: Group AS - hydrofluoric acid 10%+silane; Group S77 - silane+heating at 77 °C for 60 s; and Group AS77 - hydrofluoric acid 10%+silane+heating at 77 °C for 60 s. Ceramic blocks were cemented to composite resin blocks with a resin cement. The sets were subsequently cross-sectioned into 1 mm2 beams for μTBS testing. The beams of each group were randomly divided into two subgroups: aging (thermocycling, 12,000 cycles between 5 °C and 55 °C) and non-aging (tested immediately). One-way ANOVA and Tukey's test (α=0.05) and Weibull analysis (95% CI) were used to analyze the data. Results Group AS77 had the lowest pre-test failure number during the cutting among the groups. There was no significant difference (p=0.255) between the μTBS mean values of the non-aged groups. After aging, the mean value of S77 was significantly lower than those of AS77 and AS (p=0.005). There was no difference in the Weibull modulus (m) and characteristic strength (σ0) of the aged and non-aged groups for all comparisons. Before aging, heat treatment of silanized feldspathic ceramic (non acid-etched surface) demonstrated bond strength similar to that achieved with hydrofluoric-acid-etching treatment however, it had lower bond strength after aging. Conclusion The combination of hydrofluoric-acid-etching treatment with heat treatment silanized feldspathic ceramic did not improve the bond strength of the interface. Department of Dental Materials and Prosthodontics, Institute of Science and Technology of São José dos Campos, São Paulo State University (UNESP), Street Francisco José Longo, No. 777, Jardim São Dimas Post-graduation Program in Dentistry, Dental School, University of Passo Fundo, BR 285, Km 171 Department of Restorative Dentistry, Institute of Science and Technology of São José dos Campos, São Paulo State University (UNESP), Av. José Longo, No. 777, Jardim São Dimas Prosthodontics Unit, Faculty of Odontology, Federal University of Santa Maria, Brazil Street Floriano Peixoto, 1184 Department of Dental Materials and Prosthodontics, Institute of Science and Technology of São José dos Campos, São Paulo State University (UNESP), Street Francisco José Longo, No. 777, Jardim São Dimas Department of Restorative Dentistry, Institute of Science and Technology of São José dos Campos, São Paulo State University (UNESP), Av. José Longo, No. 777, Jardim São Dimas FAPESP: 2012/10573-5

Objectives To characterize the microstructure and determine some mechanical properties of a polymer-infiltrated ceramic-network (PICN) material (Vita Enamic, Vita Zahnfabrik) available for CAD–CAM systems. Methods Specimens were fabricated to perform quantitative and qualitative analyses of the material's microstructure and to determine the fracture toughness ( K Ic ), density ( ρ ), Poisson's ratio ( ν ) and Young's modulus ( E ). K Ic was determined using V-notched specimens and the short beam toughness method, where bar-shaped specimens were notched and 3-point loaded to fracture. ρ was calculated using Archimedes principle, and ν and E were measured using an ultrasonic thickness gauge with a combination of a pulse generator and an oscilloscope. Results Microstructural analyses showed a ceramic- and a polymer-based interpenetrating network. Mean and standard deviation values for the properties evaluated were: K Ic = 1.09 ± 0.05 MPa m 1/2 , ρ = 2.09 ± 0.01 g/cm 3 , ν = 0.23 ± 0.002 and E = 37.95 ± 0.34 GPa. Significance The PICN material showed mechanical properties between porcelains and resin-based composites, reflecting its microstructural components.

Objectives: This study evaluated the microtensile bond strength (MTBS) of non-aged and aged resin-based composites (RBC) (nanohybrid and nanofilled) after two surface conditioning methods, repaired using the composite of the same kind or a microhybrid composite. Materials and methods: Nanohybrid (Tetric EvoCeram—TE) and nanofilled (Filtek Supreme—FS) RBC blocks (5 × 5 × 6mm) (N = 128) were fabricated and randomly divided into two groups: (a) no ageing (control group) and (b) ageing (5.000 thermocycling, 5-55°C). RBC surfaces were polished by up to 1,200-grit silicone carbide papers and conditioned with either (a) air abrasion with 30-μm SiO2 particles (CoJet Sand) for 4s + silane coupling agent (ESPE-Sil) + adhesive resin (VisioBond) (n = 16) or (b) adhesive application only (Multilink A+B for TE; Adper ScotchBond 1XT for FS) (n = 16). In half of the groups, repair resin of the same kind with the RBC and, in the other half, a different kind of composite (microhybrid, Quadrant Anterior Shine—AS) with its corresponding adhesive (Quadrant UniBond) was used. The specimens were submitted to MTBS test (0.5mm/min). Data were analysed using three-way ANOVA and Tukey's tests. Degree of conversion (DC) of non-aged and aged resin composites (TE, FS) (n = 3 per group) was measured by micro-Raman analyses. Results: RBC type (p = 0.001) and ageing affected the MTBS results significantly (p = 0.001). Surface conditioning type did not show significant difference (p = 0.726), but less number of pre-test failures was experienced with the CoJet system compared to adhesive resin application only. Repair strength on aged TE showed significantly less (p

Objective: To compare stress transmission around implants with abutments made of three different materials using photoelastic, strain gage (SGA) and finite element (FEA) analyses. Methods: Three abutments – UCLA calcinable, cast in Ni-Cr; UCLA calcinable with a Cr-Co cervical collar, overcast with Ni-Cr; and a zirconia abutment – were installed on implants embedded in photoelastic resin. Vertical and oblique loads were applied to the abutments to the photoelastic and SGA analyses. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests (a=0.05). The assembly was modeled to FEA simulation. Results: Similar fringe orders were observed in the apical region under vertical load. The greatest fringe orders were observed in the coronal region of the opposite side of load application (contralateral side) under oblique load. By SGA, no statistical difference was observed among the abutments (P=0.061) under vertical load, and no difference was found between tensile and compression sides under oblique load. FEA showed no difference in stress distribution. The oblique load generated the greatest stress values on the contralateral side in the coronal area. Conclusion: Although it was not possible to establish an agreement among the analytical methods tested, different abutment materials did not influence the transmission of stresses around implants.

This article aims to associate patient-reported pain intensity in the immediate seven days after dental implant surgery with surgical factors, sex and patient age. The sample was composed of 108 patients from a dental school in southern Brazilian, between 2018 and 2020. The variables torque, pre- and postoperative medication, healing of first and second intention, gender, age, number of quadrants, number of implants and type of surgery were related to the outcome pain. Pain was reported every day by the patient until the seventh day after surgery, using a visual analogic scale (VAS). Univariate Poisson regression models were used to assess the relationship among pain and the factors. Rate ratios were obtained with 95% of confidence intervals. Overall pain was reported as moderate/intense (VAS: 3-10) by 30.56% of patients, mild pain (VAS: 1-3) by 55.56%, and no pain symptoms were reported by 13.89% of patients. Individuals which the implants were installed with high torques (50-80 N) showed more pain (p=0.03) compared to patients which the implants were installed with regular torque (30-45 N). The other factors evaluated were not significant. The torque was the most relevant factor related to pain among the evaluated by the study. High torque generates more postoperative pain than lower torque. The factors gender, age, number of operated quadrants, number of installed implants, type of surgery and pre and postoperative analgesic did not interfere in the patient's pain during the first week after surgery.