Coated nickel titanium archwires and their uncoated counterparts: In-vitro contemporary comparison of unloading forces.

OBJECTIVE: To compare the unloading forces between aesthetic nickel titanium (NiTi) wires coated with rhodium and epoxy resin, as well as their uncoated equivalents. Additionally, intragroup comparisons between the different deactivation forces were evaluated, and the inner alloy cores were determined. MATERIAL AND METHODS: Forty-four 0.018" NiTi wire segments were equally divided into 4 groups: E- NiTi coated with epoxy resin, C- NiTi uncoated, R- heat-activated NiTi coated with rhodium, and T- heat-activated NiTi uncoated. The unloading values were recorded at 0.5, 1, 2, and 3mm using a 3-point bending test, according to the method in ISO Standard 15.841. Cross-sectional scanning electron microscopy was used to assess the inner alloy core thickness of the wires. RESULTS: The intergroup comparison was successively: at 0.5mm: E (1.21)>C (0.60)=R (0.63)=T (0.58); at 1mm: E (1.30)=C (1.23)>R (0.91)=T (0.80); at 2mm:C (1.93)>E (1.36)=R (1.20) and R (1.20)=T (1.00) and E (1.36)>T (1.00); at 3mm:C (2.44)>R (2.02)>E (1.62)=T (1.68). The intragroup comparisons showed for all groups that the forces were statistically higher at 3mm than the other deactivations (p<0.01). Group E presented a reduced inner alloy core (.0155). CONCLUSION: The unloading forces demonstrated variability between the wires tested and between the different deactivations. Therefore, depending on the type of movement required and the periodontal conditions, orthodontists should pay attention during archwire selection.

Comparison of gingival display in smile attractiveness among restorative dentists, orthodontists, prosthodontists, periodontists, and laypeople.

STATEMENT OF PROBLEM: Multidisciplinary treatment needs a common goal, and dentists should understand the esthetic perception of laypeople and the other specialists involved. Such information is sparse. PURPOSE: The purpose of this cross-sectional study was to compare the influence of gingival display on perceived smile esthetics among restorative dentists, orthodontists, prosthodontists, periodontists, and laypeople. MATERIAL AND METHODS: Photographs of the smiles of 2 volunteers (1 female and 1 male) were manipulated on a computer to produce gingival exposure of 1, 3, and 5 mm and central incisor coverage of 3 and 5 mm. The images were evaluated by using a 100-mm visual analog scale by 155 raters divided into 5 groups (restorative dentists, orthodontists, prosthodontists, periodontists, and laypeople). RESULTS: The dental specialists, mainly orthodontists and periodontists, were more sensitive about alterations in gingival display than the laypeople. For the female smile, higher mean scores were attributed to 1 mm of gingival exposure by all groups of raters. For the male smile, 3 mm of central incisor coverage received higher mean scores, except for the laypeople, who considered gingival display of 1 mm to be more attractive. For both smiles, 5 mm of gingival display was judged to be the least attractive. CONCLUSIONS: Considering the differences in opinion between dental specialists and laypeople and the acceptable variations in gingival display, the preferences of patients should be considered in the diagnosis and treatment decision-making process.

Do laypersons perceive aesthetic differences between coated and uncoated orthodontic archwires?

INTRODUCTION: Aesthetic brackets are routinely combined with metallic wires in fixed orthodontic therapy, mainly due to the disadvantages of the clinical use of aesthetic archwires. The current situation needs to be explored in the literature by considering laypersons' perceptions. OBJECTIVE: The objective of this cross-sectional study was to evaluate laypersons' aesthetic perceptions of metal archwires with and without aesthetic coating. Three age ranges and both sexes were evaluated. METHODS: A volunteer using fixed aesthetic orthodontic appliance was photographed wearing the following archwires: stainless steel, nickel-titanium (NiTi), NiTi coated with epoxy resin and NiTi coated with rhodium. Using a 100-mm visual analog scale, 90 laypersons evaluated the photographs. Sex and age ranges (18-30, 31-45, over 46 years of age) were evaluated. The comparisons between the archwires and between age ranges were made using ANOVA and Tukey's test. Genders were compared using Mann-Whitney test. RESULTS: The results showed that the evaluators considered the archwire coated with epoxy resin to be the most aesthetic (60.64 ± 13.04) and the NiTi wire to be the least aesthetic (30.82 ± 7.79) (p< 0.05). Only the range of 31-45 years of age considered the NiTi archwires less aesthetic, when compared with the other age groups. For the other archwires, no statistically significant difference were found between the age groups. No differences between the sexes were detected. CONCLUSIONS: The results indicated that the aesthetic coated archwires represent an improvement in the visual aspect of ceramic brackets. The epoxy-coated metal wire was considered the most aesthetic option.

Do laypersons perceive aesthetic differences between coated and uncoated orthodontic archwires?

ABSTRACT Introduction: Aesthetic brackets are routinely combined with metallic wires in fixed orthodontic therapy, mainly due to the disadvantages of the clinical use of aesthetic archwires. The current situation needs to be explored in the literature by considering laypersons' perceptions. Objective: The objective of this cross-sectional study was to evaluate laypersons' aesthetic perceptions of metal archwires with and without aesthetic coating. Three age ranges and both sexes were evaluated. Methods: A volunteer using fixed aesthetic orthodontic appliance was photographed wearing the following archwires: stainless steel, nickel-titanium (NiTi), NiTi coated with epoxy resin and NiTi coated with rhodium. Using a 100-mm visual analog scale, 90 laypersons evaluated the photographs. Sex and age ranges (18-30, 31-45, over 46 years of age) were evaluated. The comparisons between the archwires and between age ranges were made using ANOVA and Tukey's test. Genders were compared using Mann-Whitney test. Results: The results showed that the evaluators considered the archwire coated with epoxy resin to be the most aesthetic (60.64 ± 13.04) and the NiTi wire to be the least aesthetic (30.82 ± 7.79) (p< 0.05). Only the range of 31-45 years of age considered the NiTi archwires less aesthetic, when compared with the other age groups. For the other archwires, no statistically significant difference were found between the age groups. No differences between the sexes were detected. Conclusions: The results indicated that the aesthetic coated archwires represent an improvement in the visual aspect of ceramic brackets. The epoxy-coated metal wire was considered the most aesthetic option.

RESUMO Introdução: rotineiramente na terapia ortodôntica fixa, utilizam-se braquetes estéticos combinados com fios metálicos, principalmente devido a algumas desvantagens no uso clínico dos fios estéticos. A percepção estética dos leigos nessa situação precisa ser explorada na literatura. Objetivo: o objetivo deste estudo transversal foi avaliar a percepção estética dos leigos em relação aos fios ortodônticos metálicos recobertos ou não por materiais estéticos. Três faixas etárias, dos dois sexos, foram avaliadas. Métodos: uma paciente usando aparelho ortodôntico fixo estético foi fotografada com os seguintes fios ortodônticos: aço inoxidável, níquel-titânio (NiTi), NiTi recoberto por resina epóxica e NiTi recoberto por ródio. As fotografias foram avaliadas por 90 leigos, utilizando-se uma escala visual analógica de 100-mm. Ambos os sexos e diferentes faixas etárias (18-30, 31-45 e acima de 46 anos) foram avaliados. As comparações entre os fios e entre as faixas etárias foram realizadas aplicando-se os testes ANOVA e Tukey. Os sexos foram comparados utilizando-se o teste de Mann-Whitney. Resultados: os resultados demonstraram que os avaliadores consideraram o fio recoberto por resina epóxica como o mais estético (60,64 ± 13,04) e o fio de NiTi foi classificado como o menos estético (30,82 ± 7,79) (p< 0,05). Apenas a faixa etária de 31-45 anos considerou o fio de NiTi menos estético, quando comparada às outras faixas etárias; para os outros fios, não foi observada diferença estatisticamente significativa entre as faixas etárias. Não foi detectada diferença entre os sexos. Conclusões: os resultados indicaram que os fios estéticos recobertos melhoraram o aspecto visual dos braquetes cerâmicos. O fio metálico recoberto por resina epóxica foi considerado a opção mais estética.

Effect of epigallocatechin-3- gallate solutions on bond durability at the adhesive interface in caries-affected dentin.

Hydrolytic and enzymatic degradation by matrix metalloproteinases (MMPs) reduces the durability of composite resin restorations on caries-affected dentin (CAD). The use of MMP inhibitors such as epigallocatechin-3-gallate (EGCG) could increase the longevity of the bond to dentin. This study aimed to evaluate the use of EGCG at different aqueous concentrations on the resin-dentin microtensile bond strength (µTBS), fracture pattern and nanoleakage (NL) in immediate (IM) time interval and after 12-months of water storage (1Y) when using a two-step etch-and-rinse adhesive system on CAD. Dentin surfaces of 40 human molars were submitted to a microbiological caries induction protocol and randomized into 5 groups (n = 8) (0.02% EGCG; 0.2% EGCG; 0.5% EGCG; 2% Chlorhexidine [CHX] and no treatment as Control Group - [NT]). After acid etching, the solutions were applied for 60 s followed by application of dental adhesive (Adper Single Bond 2, 3 M ESPE) to CAD surfaces. Subsequently, a resin composite (4 mm) block was built on the dentin. After 24 h, the teeth were sectioned into beam-shaped specimens (cross-sectional area of 1 mm2 and 8-mm high). Half of the specimens were tested in IM and the other half after 1Y. Two samples per tooth were submitted to SEM for NL evaluation. Data were statistically analyzed by two-way ANOVA and Tukey tests (α = 0.05). The results showed that use of EGCG and CHX did not affect µTBS in IM (p > 0.05). After 1Y, there was a reduction in µTBS for all experimental groups (p < 0.05). Adhesive fractures predominated in IM in all groups, except for 0.05% EGCG and NT. After 1Y, there was an increase in these adhesive fractures in all groups. For NL, all agents applied reduced NL in comparison with CT (p < 0.001). CHX showed lower NL (p < 0.001), followed by 0.02% and 0.5% EGCG. NT showed highest NL for both time intervals (p < 0.001). Thus, although the use of EGCG at different concentrations and CHX reduced the NL, they were unable to reduce degradation of µTBS to CAD over time.

Relationship between facial morphology, anterior open bite and non-nutritive sucking habits during the primary dentition stage

INTRODUCTION: Non-nutritive sucking habits (NNSHs) can cause occlusal alterations, including anterior open bite (AOB). However, not all patients develop this malocclusion. Therefore, the emergence of AOB does not depend on deleterious habits, only. OBJECTIVE: Investigate a potential association between non-nutritive sucking habits (NNSHs), anterior open bite (AOB) and facial morphology (FM). METHODS: 176 children in the primary dentition stage were selected. Intra and extraoral clinical examinations were performed and the children's legal guardians were asked to respond to a questionnaire comprising issues related to non-nutritive sucking habits (NNSHs). RESULTS: A statistically significant relationship was found between non-nutritive sucking habits (NNSHs) and anterior open bite (AOB). However, no association was found between these factors and children's facial morphology (FM). CONCLUSIONS: Non-nutritive sucking habits (NNSHs) during the primary dentition stage play a key role in determining anterior open bite (AOB) malocclusion regardless of patient's morphological facial pattern (FM). .

INTRODUÇÃO: os hábitos de sucção não nutritiva podem causar alterações oclusais, como, por exemplo, a mordida aberta anterior (MAA). No entanto, nem todos os pacientes desenvolvem essa má oclusão. Sendo assim, a instalação da MAA não depende apenas da ocorrência do hábito. OBJETIVO: avaliar a possível associação entre hábito de sucção não nutritiva, mordida aberta anterior e morfologia facial. MÉTODOS: foram selecionadas 176 crianças na fase de dentição decídua completa. Exames clínicos intra- e extrabucais foram realizados, e um questionário, com aspectos relacionados aos hábitos de sucção não nutritiva, foi aplicado aos responsáveis. RESULTADOS: encontrou-se uma relação estatisticamente significativa entre as variáveis hábito de sucção não nutritiva e MAA. Entretanto, não houve associação desses fatores com a morfologia facial da criança. CONCLUSÃO: a presença dos hábitos de sucção não nutritiva tem associação para a determinação da má oclusão de MAA, independentemente do padrão facial morfológico na dentição decídua. .

Harmonização estética do sorriso com laminados cerâmicos / Esthetic harmony of the smile with porcelain laminate veneers

Atualmente, observa-se grande valorização da estética do sorriso, o qual representa significativa influência no comportamento psicossocial do paciente. Dentre os materiais odontológicos utilizados, os laminados cerâmicos apresentam excelentes propriedades ópticas e podem ser empregados com previsibilidade e segurança, sem necessidade de desgastes da estrutura dental. O objetivo deste trabalho é apresentar um caso clínico em que, após a verificação da insatisfação estética dos dentes, relatada pela paciente, foi planejada a confecção de seis laminados cerâmicos. Os laminados cerâmicos confeccionados a partir de vidro ceramizado à base de dissilicato de lítio foram cimentados sobre o esmalte não desgastado, recriando uma nova dimensão aos dentes anteriores. Foi possível concluir que, por meio de uma análise estética minuciosa e a elaboração de um planejamento criterioso, o emprego de laminados cerâmicos garantiu o resultado estético almejado pela paciente e equipe odontológica.

Today, people value the smile esthetics, and this strongly influences the psychosocial behavior of the population. Among the available dental materials, porcelain laminate veneers have excellent optical properties and can be used safely and predictably without significant wear of the dental tissues. The aim of this study was to report a case where the patient complained about the esthetics and it was planned the fabrication of six porcelain laminate veneers. Lithium disilicate glass-ceramic laminate veneers were bonded to enamel without wear, rebuilding the predominance of the anterior teeth. It was concluded that after a thoughtful esthetic analysis and a thorough treatment planning, the desired esthetic result for the patient and dental team can be obtained with the use of laminate veneers.

Influence of microhybrid resin and etching times on bleached enamel for the bonding of ceramic brackets

The aim of this study was to evaluate the shear bond strength (SBS) of polycrystalline ceramic brackets (PCB) bonded after bleaching treatment using different composite resins and enamel etching times. A total of 144 bovine incisors were randomly divided into two study groups (n = 72, each) as follows: G1, enamel bleached with 35% hydrogen peroxide, and G2 (control group), enamel unbleached. After the bleaching treatment, the samples were stored in artificial saliva for 14 days. These groups were further divided into two subgroups (n = 36, each) as follows: GA, brackets bonded with Transbond XT (3M) and GB, brackets bonded with Filtek Z250 (3M). For each resin used, three different etching times with 37% phosphoric acid (15, 30 and 60 seconds) were tested. SBS tests were performed using a universal testing machine (EMIC), and the adhesive remnant index (ARI) score was verified. Significant differences among the three experimental conditions and interactions between the groups were observed. The type of composite resin accounted for 24% of the influence on the bond strength, whereas the etching time and bleaching treatment accounted for 14.5% and 10% of the influence on bond strength, respectively. The ARI revealed that the most common area of adhesion failure was at the composite resin-bracket interface. The type of composite resin, etching time and external bleaching significantly influenced the SBS of PCB on enamel, even after 14 days of saliva storage.

Influence of microhybrid resin and etching times on bleached enamel for the bonding of ceramic brackets.

The aim of this study was to evaluate the shear bond strength (SBS) of polycrystalline ceramic brackets (PCB) bonded after bleaching treatment using different composite resins and enamel etching times. A total of 144 bovine incisors were randomly divided into two study groups (n = 72, each) as follows: G1, enamel bleached with 35% hydrogen peroxide, and G2 (control group), enamel unbleached. After the bleaching treatment, the samples were stored in artificial saliva for 14 days. These groups were further divided into two subgroups (n = 36, each) as follows: GA, brackets bonded with Transbond XT (3M) and GB, brackets bonded with Filtek Z250 (3M). For each resin used, three different etching times with 37% phosphoric acid (15, 30 and 60 seconds) were tested. SBS tests were performed using a universal testing machine (EMIC), and the adhesive remnant index (ARI) score was verified. Significant differences among the three experimental conditions and interactions between the groups were observed. The type of composite resin accounted for 24% of the influence on the bond strength, whereas the etching time and bleaching treatment accounted for 14.5% and 10% of the influence on bond strength, respectively. The ARI revealed that the most common area of adhesion failure was at the composite resin-bracket interface. The type of composite resin, etching time and external bleaching significantly influenced the SBS of PCB on enamel, even after 14 days of saliva storage.

Abordagem atual para obtenção no sucesso do tratamento clareador / Up to date approach to achieve successful tooth whitening

O clareamento dental é um procedimento amplamente realizado pelos profissionais, devido ao crescimento exponencial dos pacientes em busca de dentes cada vez mais claros e harmoniosos. Embora o procedimento de clareamento dental seja relativamente simples, o profissional deve ser capaz de diagnosticar a etiologia do escurecimento e deve conhecer as diferentes técnicas e efeitos adversos do H2O2. Este artigo aborda os conceitos e aplicações do clareamento dental

Tooth whitening is widely performed by professionals due to the exponential increase of patient numbers seeking tooth whitening in order to obtain a harmonious smile. Although the whitening procedure is relatively simple, the professional must be able to diagnose the etiology of discoloration, and recognize the different techniques and side effects of hydrogen peroxide. The aim of this paper is to report the concepts and applications of tooth whitening