Microbial Adhesion and Biofilm Formation on Bioactive Surfaces of Ti-35Nb-7Zr-5Ta Alloy Created by Anodization.

This study evaluated the microbial colonization (adhesion and biofilm) on modified surfaces of a titanium alloy, Ti-35Nb-7Zr-5Ta, anodized with Ca and P or F ions, with and without silver deposition. The chemical composition, surface topography, roughness (Ra), and surface free energy were evaluated before and after the surface modifications (anodizing). Adhesion and biofilm formation on saliva-coated discs by primary colonizing species (Streptococcus sanguinis, Streptococcus gordonii, Actinomyces naeslundii) and a periodontal pathogen (Porphyromonasgingivalis) were assessed. The surfaces of titanium alloys were modified after anodizing with volcano-shaped micropores with Ca and P or nanosized with F, both with further silver deposition. There was an increase in the Ra values after micropores formation; CaP surfaces became more hydrophilic than other surfaces, showing the highest polar component. For adhesion, no difference was detected for S. gordonii on all surfaces, and some differences were observed for the other three species. No differences were found for biofilm formation per species on all surfaces. However, S. gordonii biofilm counts on distinct surfaces were lower than S. sanguinis, A. naeslundii, and P. gingivalis on some surfaces. Therefore, anodized Ti-35Nb-7Zr-5Ta affected microbial adhesion and subsequent biofilm, but silver deposition did not hinder the colonization of these microorganisms.

Surface properties of a new lithium disilicate glass-ceramic after grinding.

This study aimed to evaluate the effect of grinding on some surface properties of two lithium disilicate-based glass-ceramics, one experimental new product denominated LaMaV Press (UFSCar-Brazil) and another commercial known as IPS e-max Press (Ivoclar), in the context of simulated clinical adjustment. Discs (N = 24, 12 mm in diameter) were separated into four groups: LaMaV Press with no grinding (E), LaMaV Press after grinding (EG), IPS e-max Press with no grinding (C), and IPS e-max Press after grinding (CG). A 0.1-mm deep grinding was carried out on EG and CG samples (final thickness of 1.4 mm) using a diamond stone in a low-speed device. The E and C samples had the same thickness. The effect of grinding on the sample surfaces was evaluated by X-ray diffraction, mechanical and optical profilometry, scanning electron microscopy, goniometry, and Vickers hardness. The mean roughness (Ra) was evaluated by Kruskal-Wallis and Student-Newman-Keuls statistics. The surface energy (SE) by the sessile drop method and Vickers hardness (VH) were analyzed using two-way ANOVA. The Ra medians were E = 1.69 µm, EG = 1.57 µm, C = 1.45 µm, and CG = 1.13 µm with p = 0.0284. The SE and VH were similar for all materials and treatments. Grinding smoothed the surfaces and did not significantly alter the hardness and surface energy of both LaMaV Press and IPS e-max Press. These glass-ceramics presented similar surface properties, and clinical adjustments can be implemented without loss of performance of both materials. A grinding standardization device developed that allowed to control the amount of grinding, the speed of rotation speed and the force exerted on the samples.

Educational program in oral health for caregivers on the oral hygiene of dependent elders / Programa educacional em saúde bucal para cuidadores sobre a higiene oral de idosos dependentes

Objective: Due increased number of elders living in long-term care institutions, actions designs to improve their oral health are essential. Thus, the aim of this study was to evaluate the impact of an educational program for the caregivers through the assessment of the oral hygiene of institutionalized elders. Material and method: The education program consisted in lectures to caregivers about oral health that were performed once a month. The subjects were 40 functionally dependent institutionalized elders and 14 caregivers. Hygiene habits, plaque index, and tongue coating/discoloration of the elders were measured before the educational program (baseline- T0) and after 6 (T1), 12 (T2), 18 (T3) and 24 months (T4). Caregivers answered questions about their knowledge, doubts and implementation of dental care (T0 to T4). Result: After analyzing the data (Friedman, Chi-square and Spearman α = 0.05), a gradual improvement in the oral hygiene of the subjects was observed, with an increased frequency of brushing (p=0.0005), a change in the brush type (p=0.0065) and a reduction in the plaque index (p<0.05) and tongue coating (p<0.05). Caregivers showed a marked improvement in their dental care knowledge. Conclusion: It was concluded that the educational program for caregivers had a positive impact in the oral health of institutionalized elderly observed by the increased in the effectiveness of oral hygiene parameters such as plaque index and tongue coating, contributing to the knowledge gain in hygiene by caregivers.

Objetivo: Devido ao aumento do número de idosos que vivem em instituições de longa permanência são essenciais projetos de ações para melhorar a saúde bucal. Assim, o objetivo deste estudo foi avaliar o impacto de um programa educacional para os cuidadores de idosos institucionalizados por meio da avaliação da higiene bucal. Material e método: O programa de educação consistiu em palestras para cuidadores sobre saúde bucal que foram realizadas uma vez por mês. Foram avaliados 40 idosos institucionalizados dependentes funcionalmente e 14 cuidadores. Os hábitos de higiene, o índice de placa e o revestimento/descoloração da língua dos idosos foram avaliados antes do programa educacional (T0) e após 6 (T1), 12 (T2), 18 (T3) e 24 meses (T4). Os cuidadores responderam perguntas sobre seus conhecimentos, suas dúvidas e sobre a implementação de cuidados bucais (T0 a T4). Resultado: Após análise dos dados (Friedman, Qui-quadrado e Spearman, α = 0,05), observou-se melhora gradual na higiene oral dos idosos, com maior freqüência de escovação (p = 0,0005), alteração do tipo de escova (p = 0,0065) e redução do índice de placa (p <0,05) e revestimento da língua (p <0,05). Os cuidadores mostraram uma melhoria acentuada no seu conhecimento sobre saúde bucal. Conclusão: Concluiu-se que o programa educacional para cuidadores teve um impacto positivo na saúde bucal dos idosos institucionalizados observado pelo aumento na eficácia dos parâmetros de higiene bucal, como índice de placa e revestimento da língua, contribuindo para o ganho de conhecimento em higiene pelos cuidadores.

Y-TZP zirconia regeneration firing: Microstructural and crystallographic changes after grinding.

This study evaluated microstructural and crystallographic phase changes after grinding (G) and regeneration firing/anneling (R) of Y-TZP ceramics. Thirty five bars (LavaTM and Ice Zirkon) were divided: Y-TZP pre-sintered, control (C), regeneration firing (R), dry grinding (DG), dry grinding+regeneration firing (DGR), wet grinding (WG) and wet grinding+regeneration firing (WGR). Grinding was conducted using a diamond bur and annealing at 1,000°C. The microstructure was analyzed by SEM and the crystalline phases by X-ray diffraction (XRD). XRD showed that pre-sintered specimens contained tetragonal and monoclinic phases, while groups C and R showed tetragonal, cubic and monoclinic phases. After grinding, the cubic phase was eliminated in all groups. Annealing (DGR and WGR) resulted in only tetragonal phase. SEM showed semi-circular cracks after grinding and homogenization of particles after annealing. After grinding, surfaces show tetragonal and monoclinic phases and R can be assumed to be necessary prior to porcelain layering when grinding is performed.

Effects of whitening dentifrice on yttria-stabilized tetragonal zirconia polycrystal surfaces after simulating brushing.

STATEMENT OF PROBLEM: The changes that occur after brushing yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) are unknown. These changes may favor the retention of microorganisms and chemisorption of water, impairing its longevity. OBJECTIVE: The purpose of this in vitro study was to evaluate the effects of a whitening dentifrice on Y-TZP surfaces after simulating 10 years of brushing. MATERIAL AND METHODS: Seventy-two bar-shaped specimens (20×4×1.2 mm) were divided into 4 groups: storage in distilled water (SW, control), brushing with distilled water (BW), brushing with dentifrice (BD), and brushing with whitening dentifrice (BWD). Brushing was conducted using a linear brushing machine (878400 cycles, 0.98 N, soft toothbrush). The mean roughness (Ra) was analyzed with a profilometer and the superficial topography with scanning electron microscopy (SEM) at baseline and after treatment. Crystalline phases were characterized using x-ray diffraction. Baseline and posttreatment Ra were analyzed using the 1-way ANOVA and Tukey HSD multiple comparison test; the paired t test was used for intragroup comparison (all α=.05). RESULTS: The Ra (µm) means (before/after treatment) were SW 0.28/0.28; BW 0.32/0.31; BD 0.28/0.36; BWD 0.30/0.20. No statistically significant difference was found for Ra at baseline (P=.108) than for posttreatment results (P<.001); the BD group had higher Ra values when compared with baseline (P=.019); the BWD group had the lowest values (P<.001). The BD surfaces showed pronounced scratches and detachment of the surface, while BWD showed smoother surfaces; similar crystallographic results among groups were observed. CONCLUSIONS: Brushing Y-TZP with conventional dentifrice increased roughness, while brushing with whitening dentifrice reduced roughness. Neither dentifrice changed the crystallographic phases after brushing.

Oral rehabilitation in a patient with special needs / Tratamento reabilitador em paciente especiaL

Cerebral palsy is a disorder caused by central nervous system injuries that can occur during the prenatal, perinatal, or postnatal periods. It is characterized by multiple abnormalities, including impairment of speech, body and motor coordination, balance, intelligence, mastication, and swallowing. Due to abnormal movements of the facial muscles, compounded by impairment of the self-cleansing mechanism of the oral cavity, patients with this condition can develop oral diseases such as caries, periodontal disease, and tooth loss. The aim of this paper is to report a case of a patient with cerebral palsy who presented with absence of the maxillary central incisors, removable prosthesis wear, and oral candidiasis. Impressions of the upper and lower arches and periapical radiographs were obtained. The lateral incisors were found to exhibit root resorption, which contraindicated their use as abutment teeth for fixed prosthodontics. In view of the patient's socioeconomic status and cerebral palsy-related limitations, a resin-bonded fixed partial denture was fabricated and nystatin solution was used for treatment of oral candidiasis. The patient had an esthetically and functionally adequate outcome.

A paralisia cerebral é uma anormalidade causada por lesões no sistema nervoso central que podem ocorrer durante o período pré, peri ou pós-natal. É caracterizada por alterações múltiplas como o comprometimento da fala, da coordenação motora e corporal, do equilíbrio, do intelecto e da mastigação e deglutição. Devido aos movimentos anormais da musculatura facial, juntamente com o comprometimento da função de autolimpeza, o paciente pode apresentar quadros de patologia bucal como a cárie, a doença periodontal e a perda dental. O objetivo deste trabalho foi relatar o caso clínico de um paciente portador de paralisia cerebral com ausência dos incisivos centrais superiores, portador de prótese removível e com um quadro de candidose bucal. Foi realizada a moldagem dos arcos superior e inferior e as radiografias periapicais. Pôde-se observar que os incisivos laterais apresentavam reabsorção radicular, o que contra indicava a sua utilização como pilares para prótese fixa. Devido às condições sócio-econômicas e limitações relacionadas a paralisia cerebral, foi confeccionada uma prótese adesiva e, para a candidose bucal foi instituído o tratamento com solução de Nistatina. O resultado do tratamento foi estética e funcionalmente adequado para o paciente.

Surface roughness and hardness of yttria stabilized zirconia (Y-TZP) after 10 years of simulated brushing / Avaliação da rugosidade e dureza da zircônia Y-TZP após simulação de 10 anos de escovação

Introduction: The Y-TZP zirconia used for prosthetic infrastructure, in some clinical situations, can be exposed to the oral environment. In these situations, a polished surface without changes is extremely important. Objective: The aim of this study was to evaluate the mean roughness (Ra) and Vickers hardness of Y-TZP zirconia (LavaTM) after simulating ten years of brushing. Material and method: Thirty-six Y-TZP bar-shaped specimens (20mm X 4mm X 1.2mm) were divided into three groups: storage in distilled water (DW, n=12, control); brushing with distilled water (BDW, n=12) and brushing with distilled water and fluoride toothpaste (BFT, n=12). Brushing was performed using a brushing machine with a soft-bristled toothbrush, simulating 10 years of brushing (878.400 cycles, 100gf). The mean roughness (Ra in µm)) and Vickers hardness (VHN) of all specimens were measured twice: before and after the experimental treatment, in profilometer and microhardness tester (500gf, 30 seconds), respectively. Data were analyzed using the two-way ANOVA test (α = 0.05). Result: The interaction between groups was not significant for roughness (p = 0.701) nor for hardness (p = 0.928). The final averages for Ra (μm) were equal to: DW - 0.63; BDW - 0.64; and, BFT - 0.68. The final averages for Vickers hardness (VHN) were: DW - 1301.16; BDW - 1316.60; and, BFT - 1299.58. Conclusion: It was concluded that the brushing with distilled or fluoridated toothpaste was not able to change the roughness and hardness of Y-TZP zirconia used in this study. .

Introdução: A zircônia estabilizada por ítria (Y-TZP) utilizada para infraestruturas protéticas pode, em algumas situações clínicas, ficar exposta ao meio bucal, e nessas situações, uma superfície sem alterações e polida é extremamente importante. Objetivo: Assim, este estudo avaliou a rugosidade média (Ra) e a dureza Vickers da zircônia LavaTM após simulação de dez anos de escovação. Material e método: Foram confeccionados 36 espécimes (20mm X 4mm X 1,2mm), divididos em três grupos: armazenamento em água destilada (AD, n=12, controle), escovação com água destilada (EAD, n=12) e escovação com água destilada e dentifrício fluoretado (EDF, n=12). A escovação foi realizada em máquina de escovação simulando 10 anos (878.400 ciclos, lOOgf) com escova dental macia. A rugosidade média (Ra, em µm) e a dureza Vickers (VHN) de todos os corpos-de-prova foram mensuradas em dois momentos: antes e após o tratamento experimental, em rugosímetro e microdurômetro (500gf, 30 segundos), respectivamente. Os dados foram analisados por meio do teste two-way ANOVA (α=0,05). Resultado: A interação entre os grupos não foi significativa tanto para a rugosidade (p=0,701) quanto para a dureza (p=0,928), sendo as médias finais de Ra (µm) iguais a: AD - 0,63; EAD - 0,64 e EDF - 0,68 e as de dureza Vickers (VHN) iguais a: AD - 1301,16; EAD - 1316,60 e EDF - 1299,58. Conclusão: Concluiu-se que o procedimento de escovação com água destilada ou com dentifrício fluoretado não foi capaz de alterar a rugosidade e a dureza da zircônia Y-TZP utilizada neste estudo. .

A castor oil-containing dental luting agent: effects of cyclic loading and storage time on flexural strength

Favorable results in the use of castor oil polyurethane (COP) as pulp capping, membrane material, sealer, mouthwash and in bone repair, associated with the fact that Ricinus communis is not derived from petroleum and it is abundant in Brazil, encourage researches in the development of luting agents. Objectives This study compared the flexural strength (FS) of a castor oil-containing dental luting agent with a weight percentage of 10% (wt%) of calcium carbonate (COP10) with RelyX ARC (RX) after mechanical cycling (MC) and distilled water storage. Material and Methods Sixty-four specimens (25x2x2 mm) were fabricated and divided into two groups, COP10 and RX (control). Each group was divided into 4 subgroups (n=8) according to the storage time, 24 hours (24 h) or 60 days (60 d), and the performance (MC+FS) or not (only FS) of the mechanical cycling test. The FS (10 kN; 0.5 mm/min) and MC tests (10,000 cycles, 5 Hz, 0.5 mm/min) were carried out using an MTS-810 machine. The data were analyzed using ANOVA (α=0.05). Results The obtained FS (MPa) values were: COP10 24h- 19.04±2.41; COP10 60d- 17.92±3.54; RX 24h- 75.19±3.43; RX 60d- 88.77±6.89. All the RX specimens submitted to MC fractured, while the values for COP10 after MC were as follows: COP10 24h- 17.90±1.87 and COP10 60d- 18.60±1.60. Conclusions A castor oil-containing dental luting agent with a weight percentage of 10% (wt%) of calcium carbonate is resistant to mechanical cycling without decreases in flexural strength. However, mean COP10 showed only about 25% of the RelyX ARC mean flexural strength. .

A castor oil-containing dental luting agent: effects of cyclic loading and storage time on flexural strength.

Favorable results in the use of castor oil polyurethane (COP) as pulp capping, membrane material, sealer, mouthwash and in bone repair, associated with the fact that Ricinus communis is not derived from petroleum and it is abundant in Brazil, encourage researches in the development of luting agents. Objectives This study compared the flexural strength (FS) of a castor oil-containing dental luting agent with a weight percentage of 10% (wt%) of calcium carbonate (COP10) with RelyX ARC (RX) after mechanical cycling (MC) and distilled water storage. Material and Methods Sixty-four specimens (25x2x2 mm) were fabricated and divided into two groups, COP10 and RX (control). Each group was divided into 4 subgroups (n=8) according to the storage time, 24 hours (24 h) or 60 days (60 d), and the performance (MC+FS) or not (only FS) of the mechanical cycling test. The FS (10 kN; 0.5 mm/min) and MC tests (10,000 cycles, 5 Hz, 0.5 mm/min) were carried out using an MTS-810 machine. The data were analyzed using ANOVA (α=0.05). Results The obtained FS (MPa) values were: COP10 24h- 19.04±2.41; COP10 60d- 17.92±3.54; RX 24h- 75.19±3.43; RX 60d- 88.77±6.89. All the RX specimens submitted to MC fractured, while the values for COP10 after MC were as follows: COP10 24h- 17.90±1.87 and COP10 60d- 18.60±1.60. Conclusions A castor oil-containing dental luting agent with a weight percentage of 10% (wt%) of calcium carbonate is resistant to mechanical cycling without decreases in flexural strength. However, mean COP10 showed only about 25% of the RelyX ARC mean flexural strength.

Instrumentation of dental implants: a literature review

Introduction and Objective: The aim of this study was to review the literature on the systems used to decontaminate the implant's surface. Different instruments have been proposed, but there is no agreement in the literature about which methods would be more efficient with no damage to the implant surface. It was reported the use of plastic, carbon fiber, stainless-steel and titanium curettes and also the use of other systems such as ultrasonic points with different tips, rubber cups and air abrasion. Literature review: In most of the studies, the injury caused on the titanium surface at the time of instrumentation was examined. In others, the cell adhesion on the titanium dental implants following instrumentation of the implant surface was observed. Moreover, to enhance cleaning around implants, ultrasonic systems were recently tested. Conclusion: Metal instruments can lead to major damage to implant surface, therefore, they are not indicated for decontamination of dental implants surfaces. Furthermore, non-metallic instruments, such as plastic curettes, rubber cups, air abrasion and some ultrasonic systems seem to be better choices to remove calculus and plaque of the sub- and supra-gingival peri-implant area. It is noteworthy that more studies evaluating the effects of these systems are required to establish best practices to be used in the treatment of patients with dental implants.

Diametral tensile strength and film thickness of an experimental dental luting agent derived from castor oil.

UNLABELLED: The need to develop new dental luting agents in order to improve the success of treatments has greatly motivated research. OBJECTIVE: The aim of this study was to evaluate the diametral tensile strength (DTS) and film thickness (FT) of an experimental dental luting agent derived from castor oil (COP) with or without addition of different quantities of filler (calcium carbonate - CaCO3). MATERIAL AND METHODS: Eighty specimens were manufactured (DTS N=40; FT N=40) and divided into 4 groups: Pure COP; COP 10%; COP 50% and zinc phosphate (control). The cements were mixed according to the manufacturers' recommendations and submitted to the tests. The DTS test was performed in the MTS 810 testing machine (10 KN, 0.5 mm/min). For FT test, the cements were sandwiched between two glass plates (2 cm²) and a load of 15 kg was applied vertically on the top of the specimen for 10 min. The data were analyzed by means of one-way ANOVA and Tukey's test (α=0.05). RESULTS: The values of DTS (MPa) were: Pure COP- 10.94 ± 1.30; COP 10%- 30.06 ± 0.64; COP 50%- 29.87 ± 0.27; zinc phosphate- 4.88 ± 0.96. The values of FT (µm) were: Pure COP- 31.09 ± 3.16; COP 10%- 17.05 ± 4.83; COP 50%- 13.03 ± 4.83; Zinc Phosphate- 20.00 ± 0.12. One-way ANOVA showed statistically significant differences among the groups (DTS - p=1.01E-40; FT - p=2.4E-10). CONCLUSION: The experimental dental luting agent with 50% of filler showed the best diametral tensile strength and film thickness.

Diametral tensile strength and film thickness of an experimental dental luting agent derived from castor oil

The need to develop new dental luting agents in order to improve the success of treatments has greatly motivated research. OBJECTIVE: The aim of this study was to evaluate the diametral tensile strength (DTS) and film thickness (FT) of an experimental dental luting agent derived from castor oil (COP) with or without addition of different quantities of filler (calcium carbonate - CaCO3). MATERIAL AND METHODS: Eighty specimens were manufactured (DTS N=40; FT N=40) and divided into 4 groups: Pure COP; COP 10 percent; COP 50 percent and zinc phosphate (control). The cements were mixed according to the manufacturers' recommendations and submitted to the tests. The DTS test was performed in the MTS 810 testing machine (10 KN, 0.5 mm/min). For FT test, the cements were sandwiched between two glass plates (2 cm²) and a load of 15 kg was applied vertically on the top of the specimen for 10 min. The data were analyzed by means of one-way ANOVA and Tukey's test (α=0.05). RESULTS: The values of DTS (MPa) were: Pure COP- 10.94±1.30; COP 10 percent- 30.06±0.64; COP 50 percent- 29.87±0.27; zinc phosphate- 4.88±0.96. The values of FT (µm) were: Pure COP- 31.09±3.16; COP 10 percent- 17.05±4.83; COP 50 percent- 13.03±4.83; Zinc Phosphate- 20.00±0.12. One-way ANOVA showed statistically significant differences among the groups (DTS - p=1.01E-40; FT - p=2.4E-10). CONCLUSION: The experimental dental luting agent with 50 percent of filler showed the best diametral tensile strength and film thickness.

Influência de diferentes métodos de limpeza sobre a eficiência decorte e as características morfológicas de fresas Carbide / Influence of different cleaning methods on the cutting efficiency and morphological characteristics of Carbide burs

Introdução: Atualmente, existem muitas dúvidas em relação aos métodos de limpeza de fresas, o que estimula o estudo desses métodos visando maior eficiência e menor prejuízo desses instrumentos rotatórios. Objetivo: Avaliar a influência de métodos de limpeza sobre a eficiência de corte e sobre as características morfológicas de fresas de açoinoxidável de carbeto de tungstênio (carbide). Material e método: Trinta fresas foram divididas em cinco grupos (n = 6), de acordo com o método de limpeza: L1- escova de aço; L2- escova de nylon; L3- ultrassom + água destilada; L4- ultrassom + solução desincrustante; L5- nenhum método de limpeza (controle). As fresas foram utilizadas para o corte de esmalte dental bovino durante seis períodos de 12 minutos cada. Após cada período, as fresas eram limpas (exceto L5) seguindo o protocolo estabelecido para cada grupo. A eficiência de corte foi determinada pelo método da perda de massa e as características morfológicas, por meio de análise fotomicrográfica. Resultado: As médias da quantidade de desgaste após 72 minutos de uso foram: L1 = 0,3558 g; L2 = 0,4275 g; L3 = 0,4652 g; L4 = 0,4396 g, e L5 = 0,4854 g. Houve diferença significante para o tempo de uso (p < 0,001) e o método de limpeza (p < 0,001). O grupo L1 apresentou pior desempenho. Independentemente do grupo experimental, a análise morfológica revelou alterações nas lâminas de corte a partir de 12 minutos, sendo o grupo L1 o mais afetado. Conclusão: O método mais prejudicial à eficiência de corte e que mais alterou as características morfológicas das fresas carbide foi a limpeza com escova de aço.

Introduction: Currently, there are many questions regarding the cleaning methods seeking greater efficiency and less loss of burs. Aim: the aim of this study was to evaluate the influence of cleaning methods on the cutting efficiency and morphological characteristics of stainless steel burs tungsten carbide (carbide). Materials and method: Thirty burs were divided into five groups (n = 5) according with the cleaning method: L1- steel brush, L2- nylon brush, L3- ultrasound + distilled water, L4- ultrasound + descaling solution and L5- no cleaning method (control). Theburs were used for the cutting of bovine enamel during six periods of 12 minutes each. After each period, the burs were cleaned (except L5) following the protocol established for each group. The cutting efficiency was determined by mass loss and morphological characteristics. Result: The average amount of wear after 72 minutes of use were L1 = 0.3558 g; L2 = 0.4275 g; L3 = 0.4652 g; L4 = 0.4396 g e L5 = 0.4854 g; significant differences in the time of use (p < 0.001) and cleaning method (p < 0.001). The L1 group showed the worst performance. Regardless of theexperimental group, morphological analysis revealed alterations in the cutting blades soon after the first 12 minutes, being L1 the most affected group. Conclusion: The cleaning with wire brush was the most damaging method to the cutting efficiency and to the morphology of carbide burs.

Síndrome da ardência bucal: avaliação e tratamento / Burning mouth syndrome: evaluation and treatment

A síndrome da ardência bucal (SAB) constitui uma patologia relevante por ser definida como uma dor crônica de difícil diagnóstico e tratamento, frequente em todo o mundo e que acomete aproximadamente 15% das pessoas idosas e de meia idade. Caracterizada pela presença de dor por queimação em mais de uma área, como, por exemplo, os dois terços anteriores da língua, a metade anterior do palato duro e a mucosa do lábio superior, a SAB está associada a sinais clínicos de normalidade e achados laboratoriais normais. Sua etiologia é considerada controversa e denominada multifatorial por muitos estudos, os quais incluem, como agentes causais, fatores locais, neuropáticos, psicológicos e sistêmicos. Tais controvérsias tornam o diagnóstico diferencial difícil, principalmente se o cirurgião-dentista não tiver conhecimento a respeito da síndrome. Dessa forma, o objetivo deste artigo é apresentar, por meio de uma revisão de literatura, as principais características da SAB, indicar os procedimentos que podem ser úteis ao diagnóstico, além das modalidades terapêuticas disponíveis, no intuito de ampliar o conhecimento dos profissionais da área da saúde para que os pacientes acometidos possam beneficiar-se do tratamento adequado, apoio e confiança profissional, sempre objetivando a melhor qualidade de vida do paciente

The burning mouth syndrome (BMS) is a relevant pathology that has been defined as a chronic pain with difficult diagnosis and treatment. The prevalence of BMS is estimate to be 15% of the general population, being more common in the elderly and middle-aged. Characterized by a burning sensation in more than one area, more frequently on the two thirds of the tongue, on the anterior half of the hard palate and on the mucosa of the upper lip, the BMS is associated with clinical signs of normality and normal laboratory findings. For several studies the BMS etiology is controversial because it is multifactorial since it can be caused by local, neuropathic, psychological and/or systemic factors. These controversies make the diagnosis more difficult, especially if the dentist does not have knowledge about the syndrome. Thus, the aim of this paper is to present, by means of a literature review, the main features of BMS, indicating the procedures that may be useful for diagnosis, and also the available therapeutic modalities in order to increasing the knowledge of health professionals so that patients with BMS may benefit from appropriate treatment, support and professional confidence, always aiming to better quality of life

Topografia superficial e aderência de Streptococcus mutans no titânio após imersão e escovação com dentifrícios fluoretado e não-fluoretado simulando 10 anos de uso / Surface topography and Streptococcus mutans adhesion to titanium after brushing with fluoride and fluoride-free toothpaste simulating 10 years of use

Este estudo teve por objetivo avaliar a topografia e a aderência de Streptococcus mutans na superfície do titânio após procedimentos que simularam 10 anos de uso de dentifrícios fluoretado e não-fluoretado. Corpos-de-prova na forma de discos (6 mm Ø X 4 mm) de Ti-6Al-4V (Grupo L, N = 36) e de titânio comercialmente puro (Ti cp, Grupo T, N = 36) foram polidos metalograficamente e subdivididos em seis subgrupos (n=6) de acordo com a imersão (I) ou escovação (E) em água destilada (A), água destilada + dentifrício não-fluoretado (D) ou água destilada + dentifrício fluoretado (1500 ppm, pH 6,3) (DF). Os discos dos subgrupos IA, ID e IDF permaneceram submersos em suas respectivas soluções durante 244 h (=~ 10 anos). A escovação dos discos dos subgrupos EA, ED e EDF foi realizada em uma máquina de escovação linear com escovas macias (244 h; 60 ciclos/min). A topografia superficial dos discos foi avaliada antes (pré-tratamento) e após (pós-tratamento) a imersão ou a escovação. Para tanto, os discos foram analisados em microscópio de força atômica (MFA), no qual foram obtidas imagens tri-dimensionais (3D) e valores de rugosidade média (Ra). Após os tratamentos, discos dos subgrupos IDF e EDF foram analisados em microscopia dispersiva de raios-X (EDX) para a identificação dos elementos químicos. No teste de aderência, os discos foram contaminados com cepa padrão de Streptococcus mutans (NTCC 1023) para determinação do número de unidades formadoras de colônia (UFC/mL) das bactérias aderidas. Para averiguação do padrão de aderência dos micro-organismos, os discos foram analisados em microscópio eletrônico de varredura (MEV). As comparações entre os subgrupos foram realizadas por meio da análise de variância (one way ANOVA) e teste de Tukey HSD (α=0,05). Os valores de Ra pré e póstratamento foram comparados pelo Teste T-Student (α=0,05). Antes dos tratamentos, nenhuma diferença significante foi encontrada tanto para os discos do grupo L (p = 0,40), quanto para os do grupo T (p = 0,99). A imersão não alterou a Ra dos discos (p > 0,05). Ambos os metais mostraram aumento da Ra após escovação com dentifrícios (p < 0,01). Alterações nas imagens 3D foram observadas nos subgrupos do grupo L submetidos à escovação com dentifrício (ED e EDF) e, em todos os subgrupos do grupo T submetidos à escovação (EA, ED e EDF). O EDX não detectou íons de sódio ou de flúor nas superfícies dos discos expostos ao dentifrício fluoretado. Com relação ao teste de aderência, as médias de UFC/mL apresentaram diferenças estatisticamente significantes em função dos tratamentos realizados (Grupo L ­ p = 0,81; Grupo T ­ p = 0,52). A MEV não mostrou diferença no padrão de aderência. Concluiu-se que após 10 anos, a topografia superficial da liga Ti-6Al-4V e do Ti cp foram alteradas quando a exposição ao flúor (1.500 ppm; pH = 6,3) esteve associada à escovação. Entretanto, tais alterações ocorreram em escala nanométrica, não sendo capazes de influenciar a aderência de Streptococcus mutans.

Titanium exposure to fluorides could degrade the metal surface, contributing to an increased roughness and providing additional sites to micro-organisms adhesion. The aim of this study was to contrasting titanium surface topography after procedures that simulated 10 years of brushing using toothpastes with or without fluoride. Ti-6Al-4V (Group L - N=36) and commercially pure titanium (cp Ti - Group T; N=36) disks (6mm Ø X 4mm) were mirror-polished and treated according to 6 subgroups (n=6) as a function of immersion (I) or brushing (B) using distilled water (W), distilled water + fluoride-free toothpaste (T) and distilled water + fluoride toothpaste (1,500 ppm; pH = 6.3) (FT). Specimens submitted to immersion were submerged in the vehicles without brushing for 244 h (=~ 10 years). For brushed specimens, procedures were carried out in a linear brushing machine with a soft-bristled toothbrush (244 h; 60 cycles/min). Surface topography was evaluated at baseline (pre-treatment) and post-treatment, using atomic force microscope in order to obtain three-dimensional (3D) images and mean roughness (Ra). IFT and BFT samples were analyzed under scanning electron microscope with dispersive spectrometer (EDX). For the adhesion test, the disks were contaminated with standard strain of S. mutans (NTCC 1023) and the adhesion was analyzed by the colony-forming unit counts (CFU/mL) of the adhered viable cell and by scanning electron microscopy (SEM) images. The subgroups were compared with one-way ANOVA and Tukey post-test (α =.05). Pre and post-treatment values of Ra were compared using the paired Student T test (α=.05). At baseline, there was no significant difference among the Ra values of L subgroups (p = .40), or among T subgroups (p = .99). No significant changes were seen after immersions (p>.05). Brushing increased the roughness of cp Ti and of Ti-6Al-4V (p<.01); cp Ti had topographic changes after BW, BT and BFT treatments while Ti-6Al-4V was significantly different only after BT and BTF. EDX has not detected fluoride or sodium ions on metal surfaces. No significant differences were seen on the CFU/mL among Ti-6Al-4V (p = 0.81), or among the subgroups of cp Ti subgroups (p = 0.52). All SEM surfaces had similar patterns of Streptococcus mutans adhesion. It was concluded that after 10 years, the cp Ti and Ti-6Al-4V surface topography were changed when the titanium exposure to fluoride (1,500 ppm, pH = 6.3) was associated with brushing. However, these changes occurred in the nanometer scale and did not influence the adherence of Streptococcus mutans.

The influence of short-heating-cycle investments on the quality of commercially pure titanium castings.

STATEMENT OF PROBLEM: A new short-cycle, spinel-based investment was developed to minimize the long heating cycle generally required for conventional investments for titanium castings, but the quality of castings made using this material has yet to be evaluated. PURPOSE: The purpose of this study was to compare the Vickers hardness, castability, surface roughness, in vitro marginal misfit, and internal porosity of castings made using silica phosphate-based and spinel-based investments. MATERIAL AND METHODS: The specimens were commercially pure titanium cast using silica phosphate-based investment, Rematitan Plus (RP), and spinel-based investments, Rematitan Ultra (RU) or short-heat-cycle Trinell (TR). Disc-shaped patterns (6 × 3 mm) were cast, and Vickers hardness was measured at the surface, and 50, 100, 150, and 200 µm beneath the surface (n=10). Microstructure was analyzed by optical microscopy (×100). Mesh patterns (14 × 14 × 0.5 mm) were used for castability testing (n=10). Surface roughness (Ra) was measured on disc-shaped patterns (13 × 3 mm) with a profilometer (n=8). Wax copings were cast, screwed to implant abutments, and the marginal misfit was measured using image analysis software (n=10). Internal porosity of the copings was evaluated by density comparisons (n=10). Hardness data were analyzed by 2-way ANOVA and the Tukey HSD test. Castability, surface roughness, and marginal misfit were analyzed by 1-way ANOVA and the Tukey HSD test, and internal porosity by Kruskal-Wallis and Student-Newman-Keuls tests (α=.05). RESULTS: RP had the highest hardness values at the surface and 50 µm beneath, but the hardness values of TR, RU, and RP were statistically equivalent at 100, 150, and 200 µm. Significant differences were seen when comparing RU and TR with RP for castability (P<.001), surface roughness (P<.001), and marginal misfit (P<.001). No significant differences were seen for internal porosity. CONCLUSIONS: The quality of castings made from the new investment, TR, was similar to the quality of those made using the conventional spinel-based investment, RU, and superior to those made using RP.

Pesquisas com células-tronco: histórico geral e aplicações nas especialidades odontológicas / Stem cells research: general historic and dentistry applications

Diante dos resultados promissores de estudos nas áreas médicas e do aumento no número de pesquisas que englobam a bioengenharia e a odontologia, o objetivo deste estudo foi revisar a literatura com a finalidade de expor os aspectos gerais importantes no histórico das pesquisas com células-tronco e as diferentes aplicações nas especialidades odontológicas. Esta revisão da literatura foi baseada em levantamento bibliográfico na base de dados PubMed, relativo ao período de 1954 a 2010, onde foram utilizadas as palavras-chave “stem cell, temporomandibular joint; periodontal ligament; pulp cells; implant” para a seleção dos artigos. Apesar de a prática odontológica ser atualmente baseada em técnicas restauradoras consagradas que consistem na utilização de materiais restauradores e implantes metálicos, o sucesso relativo ao isolamento e cultivo de células provenientes do ligamento periodontal, da articulação temporomandibular e da polpa dentária destaca a possibilidade de, num futuro próximo, a atuação do cirurgião-dentista poder estar diretamente relacionada à utilização de células-tronco e à bioengenharia.

Because of the promising results presented by studies in medical areas and also due to the increase in the number of researches that associated biomedical engineering with dentistry, the aim of this study was to review and show the most important aspects of stem cells research and their different applications in dentistry. This literature review was based on PubMed bibliographical results from 1954 to 2010, where the keywords “stem cell, temporomandibular joint; periodontal ligament; pulp cells; implant” were used. Despite of dentistry practice had been based on restorative techniques that use restorative materials and metallic implants, the relative success of the isolation and cultivation of stem cells from the temporomandibular joint, periodontal ligament and pulp cells emphasize that the possibility of dentist’s performance will be directly relatedto the use of stem cells and biomedical engineering.

Human teeth versus bovine teeth: cutting effectiveness of diamond burs

Aim: In this study, a mass-loss method was used to verify whether bovine enamel has the same wear pattern as human enamel in cutting efficiency tests of diamond burs. Methods: Seventy-two teeth were used: 36 human molars (HT) and 36 bovine mandibular central incisors (BT). The enamel of the teeth was cut using diamond bur #1092 attached to a high-speed handpiece under controlled pressure (50-80 g). Each bur (n=12) cut for a total of 72 min, divided into 6 periods of12 min each (12-min, 24-min, 36-min, 48-min, 60-min, and 72-min). The amount of enamel removed was determined by the difference between pre- and post-cut tooth masses. Results:The mean amounts (g) of enamel removed were: HT- 12-min=0.11; 24-min=0.12; 36-min=0.11; 48-min=0.11; 60-min=0.10; 72-min=0.12; BT- 12-min=0.12; 24-min=0.15; 36-min=0.15; 48-min=0.13; 60-min=0.16; 72-min=0.14. Data were analyzed using ANOVA followed by Tukey’s test, and the results showed statistically significant differences between human and bovine teeth (p<0.001) and among the cutting periods (p<0.001).Conclusions: It was concluded that the cutting efficiency of the burs was different between the tested substrates, and that bovine enamel underwent greater mass loss than did human enamel.

Influence of microwave sterilization on the cutting capacity of carbide burs.

OBJECTIVE: This study compared the cutting capacity of carbide burs sterilized with microwaves and traditional sterilization methods. MATERIAL AND METHODS: Sixty burs were divided into 5 groups according to the sterilization methods: dry heat (G1), autoclave (G2), microwave irradiation (G3), glutaraldehyde (G4) or control - no sterilization (G5). The burs were used to cut glass plates in a cutting machine set for twelve 2.5-min periods and, after each period, they were sterilized (except G5) following the protocol established for each group. The cutting capacity of the burs was determined by a weight-loss method. Data were analyzed statistically by Kruskal-Wallis and Dunn's test. RESULTS: The means of the cutting amount performed by each group after the 12 periods were G1 = 0.2167 +/- 0.0627 g; G2 = 0.2077 +/- 0.0231 g; G3 = 0.1980 +/- 0.0326 g; G4 = 0.1203 +/- 0.0459 g; G5 = 0.2642 +/- 0.0359 g. There were statistically significant differences among the groups (p<0.05); only dry heat sterilization was similar to the control. CONCLUSION: Sterilization by dry heat was the method that least affected the cutting capacity of the carbide burs and microwave sterilization was not better than traditional sterilization methods.

Influence of microwave sterilization on the cutting capacity of carbide burs

OBJECTIVE: This study compared the cutting capacity of carbide burs sterilized with microwaves and traditional sterilization methods. MATERIAL AND METHODS: Sixty burs were divided into 5 groups according to the sterilization methods: dry heat (G1), autoclave (G2), microwave irradiation (G3), glutaraldehyde (G4) or control - no sterilization (G5). The burs were used to cut glass plates in a cutting machine set for twelve 2.5-min periods and, after each period, they were sterilized (except G5) following the protocol established for each group. The cutting capacity of the burs was determined by a weight-loss method. Data were analyzed statistically by Kruskal-Wallis and Dunn's test. RESULTS: The means of the cutting amount performed by each group after the 12 periods were G1 = 0.2167 ± 0.0627 g; G2 = 0.2077 ± 0.0231 g; G3 = 0.1980 ± 0.0326 g; G4 = 0.1203 ± 0.0459 g; G5 = 0.2642 ± 0.0359 g. There were statistically significant differences among the groups (p<0.05); only dry heat sterilization was similar to the control. CONCLUSION: Sterilization by dry heat was the method that least affected the cutting capacity of the carbide burs and microwave sterilization was not better than traditional sterilization methods.