Development and Evaluation of a New Orthodontic Ligature: Frictional Force Analysis.

OBJECTIVE: To evaluate and compare the friction of different ligature modes used in orthodontics, and to propose a new ligature model for conventional brackets ("H low-friction orthodontic ligature). MATERIALS AND METHODS: Samples were randomly divided into seven experimental groups: (1) resin H ligature (H3D), designed by the authors of this study and produced in a 3D printer, with conventional bracket; (2) metal H ligature (HFM), with conventional bracket; (3) passive self-ligating bracket (SLP); (4) "8" low-friction unconventional elastic (LT8), with conventional bracket; (5) loose conventional metal ligature (MLS), with conventional bracket; (6) conventional metal ligature fully tightened (MLT), with conventional bracket; (7) conventional elastic ligature (CEL), with conventional bracket-control. All samples were subjected to mechanical static friction testing using the EMIC DL 2000 universal testing machine. STATISTICAL ANALYSIS: To assess the normality requirement, the Shapiro-Wilk test was used, which showed a non-normal distribution for the means of the groups (p < 0.05). Therefore, statistical tests were performed to assess the existence of statistically significant differences between the groups through the Kruskal-Wallis, followed by Dunn's test, pairwise comparison, p < 0.05. RESULTS: The results obtained showed lower friction values for HFM (0.002 kgf), SLP (0.003 kgf), and LT8 (0.004 kgf)-these did not differ statistically from each other. These were followed by H3D (0.020 kgf), MLS (0.049 kgf), CEL (0.12 kgf), and, finally, MLT (0.21 kgf). CONCLUSION: The lowest friction value was found for the metal H ligature, similar to the self-ligating bracket and the "8" low-friction unconventional elastic. The resin H ligature presented intermediate friction values and the highest friction force was found for the MLT group.

Effect of time and dental substrate on the bond strength of a universal adhesive system: in vitro study / Efeito do tempo e do substrato dental na resistência de união de um sistema adesivo universal: estudo in vitro

Introduction: Dentin adhesives provide union between the dental substrate and composite resin, but this union can be influenced by the cleaning agent. Objective: Evaluate the use of ozonated water as a cavity cleaning solution. Material and method: 40 bovine dental crowns were selected, divided into four groups: AD (dentin cleaning with distilled water) and AO (dentin cleaning with ozonized distilled water). Each group was divided into two storage periods (24h and 30 days) kept at 37 °C. The selected universal system adhesive was employed according to the manufacturer's instructions and light cured for 20 seconds. At that time, three cylinders were made (Tygon matrix with an internal diameter of 2 mm and a height of 2 mm) of composite resin in the crowns in the cervical, médium, and incisal regions and light cured for 30 seconds. After storage, the bonding strength was tested by micro-shear, and fracture type analysis was performed. The data were submitted to statistical analysis using the Shapiro-Wilk test with a significance level of 95%, ANOVA, and Turkey. Result: There was a statistically significant difference between the bond strength values, only in the intergroup analysis for the time of 24 hours, between the middle third of the groups (LDAO24 = 2.70 (± 2.39); LDAO30 = 3.82 (± 2.31)). The predominant fracture type for both groups was an adhesive fracture, except in the medium and incisal thirds of the AD, which was a cohesive dentin fracture. Conclusion: The utilization of ozone did not change the bond strength adhesive.

Introdução: Os adesivos dentinários proporcionam união entre o substrato dental e resina composta, porém esta união pode ser influenciada pelo agente de limpeza. Objetivo: Avaliar a influência na resistência de união (RU) de um sistema adesivo universal associado à da água ozonizada como solução de limpeza cavitária. Material e método: Foram selecionadas 40 coroas de dentes anteriores bovinos divididos em 4 grupos: AD (limpeza dentinária com água destilada) e AO (limpeza dentinária com água destilada ozonizada). Cada grupo foi subdividido em outros dois grupos de acordo com o tempo de armazenamento (24h e 30 dias) armazenados a 37ºC. A limpeza dentinária foi realizada por meio de uma seringa de 60mL de cada solução e fricção por 10 segundos. O sistema adesivo universal selecionado foi aplicado de acordo com as instruções do fabricante e fotoativado por 20 segundos. Em seguida, foram confeccionados 3 cilindros (matriz Tygon com um diâmetro interno de 2 mm e 2 mm de altura) de resina composta nas coroas nas regiões cervical, média e incisal e fotoativados por 30 segundos. Após o armazenamento foi realizado o teste de RU por microcisalhamento e análise do tipo de fratura. Os dados coletados foram submetidos a análise estatística através do teste de Shapiro Wilk com nível de significância de 95%, ANOVA e Tukey. Resultado: Houve diferença estatística significativa entre os valores de RU apenas na análise intergrupos para o tempo de 24 horas, entre o terço médio dos grupos (LDAO24 = 2,70 (± 2,39); LDAO30 = 3,82 (± 2,31)). O tipo de fratura predominante para ambos os grupos em todos os tempos foi de fratura adesiva, com exceção ao terço médio e incisal do AD, que foi fratura coesiva de dentina. Conclusão: A utilização do ozônio não alterou a resistência de união adesiva.

Auricular acupuncture in TMD - A sham-controlled, randomized, clinical trial.

This study evaluated the effect of auricular acupuncture (AA) on physical (PA) and emotional (EA) aspects of patients with temporomandibular disorders (TMDs) and compared the effect of AA with those of Sham and occlusal splints (OS). In accordance with the CONSORT guidelines, patients with TMDs were evaluated by axes I and II of the RDC-TMD. The patients were allocated among three groups: OS, Sham and AA; and followed for 8 weeks. Both intragroup and intergroup evaluation for quantitative variables were analyzed with ANOVA, one-way, followed by the Tukey test. Qualitative variables were analyzed with the Kruskal-Wallis, and Dunn tests (intergroup evaluation) and for intragroup analyses, the Friedman and Wilcoxon tests were applied. At the end of the experiment, the chi-squared test was applied to compare the three groups with respect to the number of variables that had shown improved scores. The adopted level of significance for all tests was α = 5%. Intragroup analysis showed that, in the Sham group, no improvement in performance was seen in either EA and significant was improvements in 5 variables for 9 for PA, while in the AA group, significant improvements were observed in 2 variables for EA and in 9 for PA. In the OS group at the end of this study, significant improvements were observed in 8 and 8 variables for EA and PA, respectively. The analysis of therapies used revealed that the number of variables exhibiting significantly improved outcomes after treatment was similar between the AA and OS groups, whereas the sham group showed statistically significant differences when compared with the other two groups. In conclusion, this study demonstrated that AA applied at a specific TMJ ear point was able to bring about improvements in patients with TMDs, with outcomes similar to those in patients treated with an OS. CLINICAL TRIAL REGISTRATION: RBR-69ynnw (Brazilian Registry of Clinical Trials).

Influence of Ozonated Water as an Irrigant and Dentin-cleaning Solution on the Bond Strength of Fiberglass Pins.

AIM AND OBJECTIVE: This study aimed to evaluate the effect of ozonated water used as an irrigant and dentin-cleaning solution on the bond strength of fiberglass pins in vitro, comparing it with the commonly used solutions. MATERIAL AND METHODS: Seventy-seven bovine roots were randomly divided into seven groups according to the irrigant and dentin-cleaning solution to be used: HP/HP, 2.5% sodium hypochlorite; DA/DA, distilled water; CHX/CHX, 2% chlorhexidine; OA/OA, 4 ppm ozonated water; HP/DA; HP/CHX; and HP/OA. In each group, the root canals were endodontically prepared by using the corresponding irrigant and stored in DA; after 7 days, they were cleared and cleaned with the corresponding cleaning solution. The fiberglass pins were cemented by using self-adhesive cement. After 7 days, the roots were sectioned (six discs each) and submitted to the push-out test. The type of fracture was analyzed with a 4.5x stereoscopic magnifying glass. The data were analyzed by the analysis of variance and the Tukey test at a 5% significance level. RESULTS: The OA/OA (11.67), HP/HP (11.21), and HP/OA (9.71) groups showed the highest mean push-out bond strength (MPa) in the cervical third. The same trend was maintained in the middle and apical thirds. CONCLUSION: Ozonated water and 2.5% sodium hypochlorite are the most relevant solutions for root dentin treatment. CLINICAL RELEVANCE: Teeth treated with ozonated water, sodium hypochlorite, and a combination of the two showed greater bond strength than those treated with other solutions.

Effect of two desensitizing agents applied previous to in-office bleaching on the degree of whitening and dentin sensitivity: A randomized, controlled, double-blind clinical trial.

PURPOSE: To evaluate the effect of two desensitizing agents applied before in-office bleaching, on the degree of whitening and dentin sensitivity. METHODS: Participants were randomly assigned to the groups, according to the desensitizing agent used, with n=10 for each one. The bleaching was performed with 35% hydrogen peroxide, divided according to the desensitizing agent used prior to the bleaching procedure: Placebo (PL); Desensibilize KF with potassium nitrate and 0.2% sodium fluoride (PN); and Oxa-Gel with potassium oxalate (PO). The level of color saturation was assessed at the beginning of treatment and after 1 week of its completion by means of comparative method with the aid of a color scale. The degree of sensitivity (DS) was noted by the subjects with the aid of a visual scale throughout the time that the bleaching agent remained in contact with the teeth (5, 10, 15, 20, 25 and 30 minutes) as well as 1, 24 and 48 hours after the end of application. Pain and the degree of color saturation were evaluated using the Shapiro-Wilk test. The DS was assessed by Kruskal-Wallis and Dunn's tests. The color was evaluated by ANOVA and Tukey's HSD. RESULTS: There was no significant difference in the degree of bleaching among the groups. DS was significantly more accentuated in the 48-hour period. The DS was significantly higher for the PL group and significantly lower for the PO group. The desensitizing agents reduced the DS without affecting the effectiveness of the bleaching treatment. CLINICAL SIGNIFICANCE: Both desensitizing agents provided greater control over pain compared to the placebo group. Potassium oxalate showed greater pain control than potassium nitrate. Both desensitizing agents tested did not interfere in the degree of whitening.

In vitro and In vivo evaluation of resin composites fluorescence.

This study aimed at comparatively evaluate, by visual method, the fluorescence intensity in vitro and in vivo of six resins composed of different classifications and viscosities compared to natural enamel. For the in vitro study, seventy specimens were prepared and for the in vivo study, a restoration was performed on the cervical portion of the buccal face of 6 anterior maxillary teeth, which under ultraviolet light were compared to the dental structure. The specimens and restorations were photographed only under the illumination of an ultraviolet lamp. The photographic record was performed, with standardized parameters for all photographs (ISO 100). After visual analysis of the images by three evaluators calibrated in the in vitro study and by ten evaluators calibrated in the in vivo study, numerical values were assigned to resins without fluorescence (zero), medium fluorescence (1) and high fluorescence (2). The evaluations were submitted to the Kruskal-Wallis and Dunn test, which among the limitations of this study and according to the employed methodology, it was found that there was no statistical difference in fluorescence intensity among the composite resins evaluated, since all types of resins achieved fluorescent metamerism with dental enamel.

Effect of Tricalcium Silicate on Direct Pulp Capping: Experimental Study in Rats.

OBJECTIVES: Conduct a histological comparison of the pulp response to different materials, with a focus on the continuity and morphology of the mineralized barrier after direct pulp capping. MATERIALS AND METHODS: One hundred and eight maxillary first molars of 54 Wistar rats were subject to direct pulp capping and divided into three groups according to the materials used: calcium hydroxide (CH), mineral trioxide aggregate (MTA), and Biodentine. All cavities were sealed, and the animals were euthanized at 7, 14, and 21 days. Descriptive histological evaluation of the inflammation and formation of the mineralized barrier was performed. STATISTICAL ANALYSIS: Statistical analyses were performed using the Kruskal-Wallis test, which was complemented by the Dunn test; differences with p < 0.05 were considered statistically significant. RESULTS: The results showed that MTA and Biodentine elicited less intense inflammatory reactions than CH. With respect to the formation and quality of the dentin barrier formed, differences were observed at 21 days between the analyzed groups; the best results being obtained following treatment with MTA and Biodentine. CONCLUSION: MTA and Biodentine induced formation of a more continuous and uniform mineralized barrier with less intense pulp response than CH.

Impact of dietary acids on the surface roughness and morphology of composite resins.

This in vitro study was performed to evaluate the surface roughness (Ra) and morphology by scanning electron microscopy (SEM) of composite resins that had been stored in acidic solutions typical of those present in the diet. Three composite resins (4 Seasons, Z250, and P90) were selected and divided into three groups (n = 7) according to the solutions tested: G1: distilled water; G2, Coca-cola, and G3: orange juice. The Ra test was repeated after immersion periods of 15, 90, and 180 days. The mean Ra values were subjected to LS means analysis and the Tukey-Kramer (P < 0.05). One test specimen of each composite resin was selected for SEM analysis after each period. The Ra data indicated that P90 had the lowest Ra values. 4 Seasons and Z250 had statistically similar roughness values for all the solutions and evaluation periods. With the exception of 180-day immersion in Coca-cola, 4 Seasons showed significantly higher values than Z250. SEM analysis showed that P90 was the composite resin most resistant to the actions of all acid solutions for the periods analyzed. Interaction between components of the solutions and the active components of other dietary items, as well as oral hygiene, may affect the chemical degradation of composite resins.

Bonding Strength of Luting Cement to Zirconia-Based Ceramic Under Different Surface Treatments.

OBJECTIVES: The aim of this study was to evaluate the bonding strength of self-adhesive luting cement to zirconia under different surface treatments. MATERIALS AND METHODS: Thirty-two zirconia samples were randomly divided into eight experimental groups based on the surface treatment employed (Control: no surface treatment; PMM: wear with diamond bur; JAT: blasting with glass beads; PMA: wear with a medium-roughness milling machine; Primer: primer application on the surface without treatment; PMM +Primer: PMM treatment plus primer application; JAT+Primer: JAT treatment plus primer application; and PMA+Primer: PMA treatment plus primer application). Cement cylinders were built on the ceramic surfaces, and the groups were subdivided according to the storage time employed (i.e., 24 hours or 60 days). After storage, the samples were subjected to microshear testing. STATISTICAL ANALYSIS: The Kruskal-Wallis test followed by the Dunn test was employed for comparison between the groups (p < 0.05). RESULTS: The PMM group yielded the optimal results and the mean values increased after both storage times following the primer application. The Control, PMA, and JAT groups gave similar results after 24 hours, while the JAT group gave superior results following primer application over this storage time. After 60 days of storage, all groups gave improved results following chemical treatment with a primer. CONCLUSION: It was concluded that mechanical preparation using the diamond bur followed by primer application significantly improved the bond strength between the ceramic and the luting cement.

Aged Translucent Aesthetic Zirconia: Bond Strength Analysis.

OBJECTIVE: This study evaluates the bond strength of two compositions of aesthetic translucent zirconia (TZ). MATERIALS AND METHODS: For this evaluation, test specimens were prepared from ICE Zirkon TZ and Prettau Anterior zirconia (PAZ) that were stored in distilled water at 37°C for two time periods: T1 (24 h) and T2 (90 days) to simulate aging. Two factors were evaluated for the samples-ceramic and aging time. The samples were subjected to tests of microshear strength and fracture type and were evaluated using scanning electron microscopy. RESULTS: The results were analyzed using the D'Agostino test, analysis of variance, and Tukey's test (p < 0.01). Statistically significant differences were observed for ceramic type and aging time. CONCLUSION: The results showed that PAZ provides significantly superior performance to TZ at the two aging times evaluated.

Effects of low-power laser auriculotherapy on the physical and emotional aspects in patients with temporomandibular disorders: A blind, randomized, controlled clinical trial.

OBJECTIVES: This study evaluated the effects of low-power laser auriculotherapy (LA) on the physical and emotional symptoms of patients with temporomandibular disorders (TMDs), in comparison with occlusal splints (OS). DESIGN: Randomized, blinded, prospective, non-inferiority clinical trial. INTERVENTIONS: The patients received OS (control group) or LA (experimental group). MAIN OUTCOME MEASURES: Following the Consolidated Standards of Reporting Trials (CONSORT) guidelines, patients with TMD were evaluated by using axes I and II of the Research Diagnostic Criteria for RDC-TMD. Both intra- and intergroup quantitative variables were analyzed with ANOVA (p < 0.05), while qualitative variables were analyzed with the Kruskal-Wallis (intergroup evaluations; p < 0.05) or Mann-Whitney tests (intragroup analyses; p < 0.05). RESULTS: OS improved five physical symptoms of TMD (pain in the right temporal muscle, right and left masseter muscles, left joint, and left intraoral region), while LA improved six (jaw functioning; pain in left masseter muscle, right and left joints, and right and left intraoral regions). Similarly, OS improved seven emotional symptoms (degree of depression, degree of non-specific physical symptoms, excluding pain, degree of non-specific physical symptoms including pain, average pain value in the past 6 months, presence of depression, intensity and characteristics of pain, non-specific physical symptoms including pain), while LA improved five (degree of non-specific physical symptoms including pain, presence of depression, intensity and characteristics of pain, non-specific physical symptoms including pain, non-specific physical symptoms excluding pain). CONCLUSION: LA improved the physical and emotional symptoms of TMD, with results similar to OS. CLINICAL RELEVANCE: For the physical and emotional symptoms associated with TMD, LA showed similar outcomes as OS.

Influence of Different Composites and Polishing Techniques on Periodontal Tissues near Noncarious Cervical Lesions: A Controlled, Randomized, Blinded Clinical Trial.

OBJECTIVES: This study evaluated the long-term effect on gingival tissues near noncarious cervical lesions after restoration with different composites in association with two different polishing techniques. MATERIALS AND METHODS: This study was conducted on 60 patients as a randomized, split-mouth, single-blind clinical trial and divided into four groups (n = 15) and restored using different composites (Tetric N-Ceram nanohibride or Z350 XT nanoparticles) and polishing materials (Astropol or Sof-Lex). The periodontal parameters analyzed were Silness-Löe plaque index; Silness-Löe gingival index; probing depth, clinical insertion level; and bleeding on probing. Periodontal analysis was performed before scaling and root planing at 30, 60, 120, and 180 days after restoration. STATISTICAL ANALYSIS: The data submitted to the Friedman's test were employed for comparison between groups (p < 0.05). RESULTS: Statistically significant differences between Z350/Astropol and other groups were observed for visible plaque and probing depth. Gingival index Tetric/Sof-Lex, the time factor did not influence the results. All experiment groups exhibited statistically significant differences in the clinical level of insertion when the follow-up time was considered. Percentage of bleeding on probing, in which there was a difference only with regard to group Tetric/Sof-Lex when the time factor was considered. CONCLUSION: The evaluated composites and polishing techniques did not exhibit differences in performance in the periodontal parameters analyzed at the end of 6 months of evaluation.

In vitro evaluation of the antibacterial behavior of a self-etch adhesive associated with chlorhexidine / Avaliação in vitro da ação anti-bacteriana de um adesivo auto-condicionante acrescido de clorexidina

Abstract Introduction Adhesive technology has been developed quickly since its introduction about fifty years ago. Its goal is to produce a close contact within enamel and dentin. Failures in this process could result in microleakage, and allow the infiltration of bacteria, fluids and ions. Recent studies have been shown the use of chlorhexidine associated with adhesive systems can be able to inhibit the bacteria action. Objective The aim of this study was to evaluate the addiction of different percentages of chlorhexidine to a self-etch adhesive. Methodology The solution of digluconatechlorhexidine was increased to the primer of the two pass self etch adhesive to create a 0.5%, 1.0% and 2.0% chlorhexidine primer solution and after they were distributed in four groups (G1, G2, G3 and G4). Saliva samples (N=10) were used to test bacteria activity. Result They were spread in a blood medium with filter paper disks containing the different treatments. After the incubation, the inhibitions halos formation were evaluated. Conclusion This study demonstrated that, in vitro, the addition of different percentages of chlorhexidine digluconate to the self-etch adhesive induced inhibited halos at bacteria of saliva samples, independent from their concentration.

Resumo Introdução A tecnologia adesiva vem se desenvolvendo rapidamente desde que foi introduzida há mais de 50 anos. O principal objetivo da adesão é alcançar um íntimo contato entre a estrutura dental e o material restaurador e fornecer adequada união entre o esmalte e a dentina. Objetivo A proposta deste estudo foi avaliar o efeito antibacteriano de um adesivo auto-condicionante de dois passos associado a diferentes concentrações de solução de digluconato de clorexidina (DCHX). Metodologia A solução de digluconato de clorexidina a 20% foi adicionada ao primer do sistema adesivo nas concentrações de 0,5, 1,0 e 2,0% e distribuídas em quatro grupos (G1, G2, G3 e G4). Para o teste de atividade antibacteriana foram utilizadas amostras de saliva (N=10) semeadas em meio de ágar sangue e discos de papel filtro contendo os diferentes grupos. Após incubação, as amostras foram inspecionadas quanto à formação de halo de inibição dos microrganismos através da utilização do paquímetro digital de precisão (0,0001mm) (Mitutoyou Sul Americana Ltda/ Starret Tools ®). Resultado Halos de inibição foram encontrados ao redor de todos os discos de filtro em que foram aplicados o primer acrescido de clorexidina mais o adesivo, bem como ao redor dos discos do controle positivo. Ao redor dos discos do controle negativo e dos discos com primer e adesivo não modificado não foram observados halos de inibição. Conclusão Este trabalho demonstrou que, in vitro, a adição de diferentes concentrações de digluconato de clorexidina ao sistema adesivo produziu halo de inibição dos microrganismos presentes nas amostras de saliva, independente da concentração utilizada.

The influence of three photoactivation techniques on the sorption and solubility of different composite resins / A influência de três técnicas de fotoativação na sorção e solubilidade de diferentes resinas compostas

Introduction: There is a growing demand for aesthetic restorations and the polymerized composite resins are the most used material in these procedures. In order to achieve greater resistance to solubilization proper polymerization is required. Objective: Evaluate the influence of three photoactivation techniques, on sorption and solubility of three composite resins. Materials and methods: 90 test samples measuring 8 mm diameter and 1 mm thick were made and divided into 9 groups (n=10) of resins -Filtek Z350 XT, Tetric N-Ceram and IPS Empress Direct, each of them was polymerized with LED Bluephase, using the techniques: Conventional, Soft-Start (SS) and Pulse Delay (PD). Afterwards they were placed in desiccator with silica gel at 98.6 F and weighed daily until obtaining a constant mass (m1). Then they were immersed in deionized water for seven days and weighed again (m2). The test sample reconditioning was performed using the m1 procedure, until a constant mass (m3 ) was obtained. The sorption and solubility values were calculated and subjected to ANOVA test (two-way), followed by Tukey post hoc, p<0.05. Result: There were no statistically significant differences in sorption and solubility among the studied resins when photoactivation techniques were compared. For solubility analysis, statistically significant differences were observed among the materials. The results for composite resin Filtek Z350 XT presented higher statistical hybridization values than those of the other evaluated resins. Conclusion: The different forms of photoactivation had no influence on the sorption and solubility of the tested composite resins.

Introdução: Há uma crescente demanda por restaurações estéticas, sendo as resinas compostas polimerizadas o material mais utilizados nesses procedimentos. Visando uma maior resistência à solubilização, uma polimerização adequada é necessária. Objetivo: Avaliar a influência de três técnicas de fotoativação na sorção e na solubilidade de três resinas compostas. Material e método: Foram confeccionados 90 corpos-de-prova, com 8 mm de diâmetro e 1 mm de espessura, divididos em 9 grupos (n = 10) de resinas - Filtek Z350 XT, Tetric N-Ceram e IPS Empress Direct, cada uma elas polimerizada com LED Bluephase, utilizando as técnicas: Convencional, Soft-Start (SS) e Pulse Delay (PD). Posteriormente foram colocadas em dessecador com sílica gel a 98,6 F e pesadas diariamente até obtenção de massa constante (m1). Depois foram imersos em água desionizada durante sete dias e pesados ​​novamente (m2). O recondicionamento da amostra de teste foi realizado utilizando o procedimento m1, até que uma massa constante (m3) fosse obtida. Os valores de sorção e solubilidade foram calculados e submetidos ao teste ANOVA (two-way), seguido por Tukey post hoc, p <0,05. Resultado: Não houve diferenças estatisticamente significantes para sorção e solubilidade nas resinas estudadas quanto as técnicas de fotoativação. Para análise de solubilidade, foram observadas diferenças estatisticamente significantes entre os materiais. Os resultados para resina compostaFiltek Z350 XT apresentaram valores de hibridação estatísticos superiores aos das outras resinas compostas avaliadas. Conclusão: As diferentes formas de fotoativação não influenciaram a sorção e solubilidade das resinas compostas testadas.

Restaurações cerâmicas multicamadas e monolíticas: uma revisão de literatura / Multilayered and monolithic ceramic restorations: a literature review

Objetivo: realizar uma revisão de literatura sobre materiais, técnicas de confecção, vantagens, desvantagens e limitações das restaurações cerâmicas multicamadas e monolíticas. Revisão de literatura: embora as cerâmicas odontológicas sejam utilizadas para confecção de restaurações dentárias indiretas, porque têm excelentes propriedades mecânicas e estéticas, são materiais susceptíveis à fratura sob forças oclusais. Para compensar essa fragilidade, restaurações multicamadas são confeccionadas associando um material mais resistente para a infraestrutura e a posterior aplicação de cerâmica para recobrimento estético. Porém, as restaurações multicamadas apresentam como desvantagem o possível lascamento da cerâmica de recobrimento. Essas falhas comprometem a restauração funcional e a estética, exigindo a substituição da peça protética em muitos casos. Sendo assim, devido à evolução de sistemas cerâmicos e técnicas de processamento, surgiram as restaurações cerâmicas monolíticas fabricadas com um único material, a fim de superar tal limitação. Nesse sentido, diferentes materiais e técnicas são apresentados na literatura para a confecção de restaurações cerâmicas monolíticas. Considerações finais: as restaurações multicamadas têm bom resultado estético, porém podem apresentar lascamento da cerâmica de recobrimento. Essa limitação é superada pelo uso de um único material para as restaurações monolíticas, mas o resultado estético pode ser limitado. De um modo geral, a literatura demonstra um bom comportamento clínico para as restaurações cerâmicas multicamadas e monolíticas, quando a técnica de confecção e o sistema cerâmico são bem indicados. (AU)

Objective: the aim of this study was to conduct a literature review about the materials, techniques, advantages, disadvantages and limitations of multilayer and monolitic ceramic restorations. Literature review: although dental ceramics have been used for fabrication of dental restorations due to its good esthetic and mechanical properties, it is a material prone to fracture under oclusal loading. To surpass such fragility, multilayer restorations are fabricated using a resistant framework material associated to esthetic veneering ceramic. However, multilayer restorations present risk to chipping of veneering ceramic. Those failures represent a functional and esthetic problem, leading to restoration replacement. So, the evolution of ceramic systems and techniques generated monolitic restorations using a single material. Several materials and techniques are presented in the literature for fabrication of monolitic ceramic restorations. Final considerations: multilayer restorations present good esthetic result but delamination of veneering ceramic can occur. Such limitation is solved using a single material in monolitic restorations, but esthetic result is limited. In general, literature shows appropriate clinical performance for both multilayer and monolitic ceramic restorations when technique and materials are well indicated. (AU)

Influência da solução de irrigação sobre a resistência adesiva de um cimento resinoso de dupla polimerização / Influence of solution of irrigation on the resistance of and adhesive resin cement double polymerization

Objetivo: Avaliar a influência de diferentes soluções de irrigação cavitária sobre a resistência de união de um cimento resinoso de dupla polimerização. Material e Método: A partir de incisivos bovinos, foram obtidos 4 grupos (n=15), divididos aleatoriamente de acordo com a solução irrigadora empregada na limpeza cavitária, sendo: G0 - soro fisiológico + condicionamento ácido; G1 ­ EDTA + condicionamento ácido; G2 - Clorexidina 2% + condicionamento ácido + clorexidina 2% e G3 - soro fisiológico + condicionamento ácido + clorexidina 2%. Foram confeccionados cilindros de cimento resinoso para cada coroa, utilizando-se uma matriz de Tygon com diâmetro interno de 1 mm e altura de 2 mm. O teste de resistência adesiva por microcisalhamento foi realizado após 3 meses de armazenamento dos espécimes em soro fisiológico a 37ºC. Os dados foram submetidos ao teste de Kruskall-Wallis, seguido do teste de Dunn (p<0,05). Resultados: Os grupos G0, G1 e G3 não apresentaram diferenças significativas entre si (p>0,05). Os menores valores foram observados no grupo G2 (p<0,05). Conclusões: As soluções irrigadoras EDTA e soro fisiológico utilizadas previamente ao condicionamento ácido da dentina não interferiram, significativamente, na resistência de união, porém, a solução de clorexidina utilizada após o condicionamento ácido influenciou negativamente nos valores de resistência de união.

Objectives: This study aimed to evaluate the influence of different cavity irrigation solutions on the bond strength of a dual-curing resin cement. Methods: From bovine incisors, 4 groups (n=15), were randomly divided according to the irrigating solution for cavity cleaning: G0 ­ saline + acid etching; G1 ­ EDTA + acid etching; G2: Chlorhexidine 2% + acid etching + Chlorhexidine 2%; and G3 ­ Saline + acid etching + Chlorhexidine 2%. Resin cement cylinders were made for each crown, using a Tygon matrix with internal diameter of 1 mm and height of 2 mm. The specimens were stored for 3 months at 37oC, and then subjected to microshear tests. Data were statistically analyzed by Kruskal-Wallis test followed by Dunn (p<0.05). Results: There were no statistically significant differences between G0, G1 and G3 groups (p>0.05). The lowest values were observed in G2 group (p<0.05). Conclusion: The irrigation solutions EDTA and saline used before to the acid etching of dentin did not interfere, significantly, in the bond strength, however, the solution of chlorhexidine used after the acid etching influenced negatively.

Influência de desinfetantes bucais sobre a dureza de superfície de resinas para provisórios / Influence of oral disinfectant on surface hardness of acrylic resins for provisional restorations

As restaurações provisórias têm papel importante para diagnóstico e plano de tratamento em reabilitação com prótese fixa. Quando há necessidade de procedimentos cirúrgicos pré-protéticos, meios adicionais de controle de placa bacteriana devem ser indicados, mas pouco se sabe sobre os efeitos que podem produzir na superfície de restaurações provisórias. Proposição: este estudo teve como objetivo avaliar o efeito de dois enxaguatórios bucais na dureza de duas resinas usadas para confecção de provisórios protéticos. Material e Métodos: resina acrílica autopolimerizável poli(metil metacrilato) Dencrilay Speed e resina bisacrílica Protemp 4; dois enxaguatórios bucais, Periogard (digluconato de clorexidina 0,12%) e Oral-B sem álcool, tendo soro fisiológico como grupo controle. Foram confeccionadas 60 amostras, 30 para cada resina, as quais foram divididas em 6 grupos experimentais (n=10). As amostras foram imersas nas respectivas soluções para bochecho durante 10 minutos por dia, por um período de 30 dias. Após, foram submetidas a ensaios de microdureza utilizando o penetrador tipo Knoop. Resultados: a resina acrílica Dencrilay apresentou os maiores valores de dureza, no entanto apresentou redução na dureza quando imersa no enxaguatório Periogard. A resina bisacrílica Protemp 4 não apresentou diferença nos valores de microdureza de superfície quando imersa nas soluções utilizadas. Conclusão: a resina acrílica apresentou redução na dureza de superfície após imersão em solução de clorexidina 0,12%. Implicações clínicas: a resina bisacrílica, apesar de menor dureza, apresentaria superfície mais estável em meio bucal, mesmo com o uso diário de enxaguatórios bucais

Temporary restorations have important role for diagnosis and treatment plan in rehabilitation with fixed prosthesis element. When pre-prosthetic surgical procedures are required, additional means of controlling plaque must be indicated, but little is known about the effects it can produce on the surface of provisional prosthetic restorations. Purpose: To evaluate the effect of two mouthrinses on the hardness of two resins used in temporary restorations. Material and Method: Acrylic resin poly(methyl methacrylate) Dencrilay Speed and bisacrylic resin Protemp 4, two mouthrinses, Periogard (chlorhexidine digluconate 0.12 %) and Oral- B without alcohol and saline solution as control group. Sixty samples were prepared, 30 for each resin, which were divided into 6 groups (n = 10). The specimens were immersed in respective solutions for 10 minutes per day, for 30 days. Then, microhardness tests were performed using the Knoop indenter. Data were subjected to analysis of variance and Tukey's test, with a confidence interval of 95%. Results: Dencrilay acrylic resin had the highest values of hardness, however, it showed a reduction in hardness when immersed in the mounthrinse Periogard. The bisacrylic resin Protemp 4 showed no difference in the values of surface microhardness when immersed in the solutions used. Conclusion: The acrylic resin showed a reduction in surface hardness after immersion in 0.12% chlorhexidine solution. Clinical Implications: Bisacrylic resin, although less hard, would have a more stable surface in oral environment, even with the daily use of mouthrinses.

Immediate and 6-month Bond Strengths of Different Adhesives in the Oral Environment.

PURPOSE: To evaluate the microtensile bond strength (µTBS) of three adhesives to dentin after 1 week and 6 months in an oral environment. MATERIALS AND METHODS: Class I cavities were prepared in the third molars of 30 patients and randomized into 3 groups according to the following adhesives: Scotchbond Multi-Purpose (SM), Clearfil Protect Bond (CF), and Scotchbond Universal (UN). These molars were then subdivided into two groups according to the exposure time in the oral environment: one week (1W) and 6 months (6M). After the exposure time, the teeth were extracted, cut into beams, and submitted to the µTBS test. The data were analyzed using the Shapiro-Wilk test and two-way ANOVA followed by Tukey's post-hoc test with a significance level of 5%, and fracture modes were analyzed. RESULTS: The bond strengths in MPa (mean ± SD) were SM-1W: 39.5 ± 7.9; SM-6M: 29.7 ± 1.8; CF-1W: 30.5 ± 1.4; CF-6M: 28.6 ± 4.1; UN-1W: 30.6 ± 3.2; and UN-6M: 26.7 ± 2.0. The SM-1W group exhibited significantly increased µTBS compared with the other groups. After 6 months in the oral environment, a significant reduction of µTBS was only observed for the SM group, whereas similar bond strengths were observed for the other groups. SM-1W exhibited a predominance of mixed fractures, whereas the other groups showed a predominance of adhesive fractures. CONCLUSIONS: The adhesives which were applied in the self-etching mode maintained bond strength after six months in the oral environment. A reduction of µTBS was only observed for the three-step etch-and-rinse adhesive.

Toothbrush Handles Individually Adapted for Use by Elderly Patients to Reduce Biofilm on Complete Dentures: A Pilot Study.

INTRODUCTION: Reduction of biofilm on dentures is important for maintaining denture wearers' health. OBJECTIVE: The aim of this study was to assess the effectiveness of toothbrush handles individually adapted in reducing of biofilm on dentures. MATERIALS AND METHODS: Study participants were 16 residents of the condo for the elderly, denture wearers, functionally independent and without cognitive impairment. Participants were randomly divided into two groups: Group 1 (adapted toothbrush handles) and Group 2 (conventional toothbrush). Biofilm from the inner surface of the basal area of the denture was observed using 5% erythrosine. Images obtained before starting the use of toothbrushes, after 7 and 21 days were sent for computer analysis. RESULTS: The average amount of biofilm on the first day was considered severe in both groups. At the end of the experiment, the average biofilm coverage in Group 1 was 44.7% (13.1% reduction) and in Group 2 it was 48.6% (4.8% reduction). However, the Friedman analysis of variance test showed that the reduction was statistically significant (p< 0.05) only in Group 1, demonstrating the effectiveness of the adapted brushes. CONCLUSION: The findings of this pilot study indicated that for the reduction of biofilm on dentures the adapted toothbrush handles were superior to the conventional type.

The Effect of Resin Composites and Polishing Procedure on Periodontal Tissue Parameters in Patients with Diabetes Mellitus.

The aim of this study was to establish relationship between restorative resin and periodontal tissues of patients with diabetes mellitus. We selected 30 patients, 15 patients with diabetes mellitus with a total of 30 restorations and 15 patients without diabetes mellitus with a total of 49 restorations and the periodontal parameters and restorations parameters were evaluated. The total period was 12 months. The results showed a significant improvement in periodontal parameters assessed (p < 0.05). It may be concluded that over the 12-month period, there was no adverse reaction to periodontal tissue as a result of various polishing regimes of a restorative resin-based composite in patients with diabetes mellitus.