Propiedades flexurales y estabilidad de color de materiales restauradores estéticos indirectos / Flexural properties and color stability of indirect esthetic restorative materials

Introducción: Las diferencias en las propiedades mecánicas de los materiales cerámicos y a base de resina plantean la interrogante sobre cuál puede tener un mejor desempeño a largo plazo. Objetivos: Evaluar la resistencia flexural y estabilidad de color de diferentes materiales restauradores estéticos indirectos. Métodos: Los materiales seleccionados fueron Filtek™ Z250 XT (3M ESPE), Ceramage (SHOFU Dental), VITA VM® LC y VITA ENAMIC® (VITA Zahnfabrik), IPS e.max® (Ivoclar-Vivadent) y Zolid FX (Amann Girrbach AG). El ensayo de resistencia flexural (n = 10) fue realizado en una máquina universal de ensayos mecánicos. Las lecturas de color (n = 5) se midieron en un espectrofotómetro VITA Easyshade V®. Resultados: Los materiales totalmente cerámicos mostraron un mejor desempeño mecánico (p < 0,001). Los resultados de estabilidad de color muestran que Ceramage, IPS e.max® y Zolid FX, mostraron una diferencia estadísticamente significativa (p ≤ 0,002) con Filtek Z250 XT, VITA VM® LC y VITA ENAMIC®. Conclusiones: Los materiales totalmente cerámicos presentaron una mayor resistencia flexural y estabilidad de color que los materiales de base polimérica. A pesar de ello, los materiales estéticos indirectos con polímeros en su composición, como Ceramage, se presentan como una alternativa válida, ya que además de tener propiedades mecánicas adecuadas, poseen una estabilidad de color semejante a los materiales cerámicos(AU)

Introduction: Differences in the mechanical properties of ceramic and resin-based materials pose the question of which of the two will perform better in the long run. Objectives: Evaluate the flexural resistance and color stability of different indirect esthetic restorative materials. Methods: The materials selected were Filtek™ Z250 XT (3M ESPE), Ceramage (SHOFU Dental), VITA VM® LC and VITA ENAMIC® (VITA Zahnfabrik), IPS e.max® (Ivoclar-Vivadent) and Zolid FX (Amann Girrbach AG). The flexural resistance assay (n = 10) was conducted in a universal mechanical testing machine. Color readings (n = 5) were taken with a VITA Easyshade V® spectrophotometer. Results: All-ceramic materials had better mechanical performance (p < 0.001). Color stability results show that Ceramage, IPS e.max® and Zolid FX displayed a statistically significant difference (p ≤ 0.002) with respect to Filtek Z250 XT, VITA VM® LC and VITA ENAMIC®. Conclusions: All-ceramic materials exhibited greater flexural resistance and color stability than polymer-based materials. However, indirect esthetic materials with polymers in their composition, such as Ceramage, are presented as a valid alternative, due to their appropriate mechanical properties and their color stability, which is similar to that of ceramic materials(AU)

Microfiltración marginal de resinas de relleno masivo y nanohíbrida en molares deciduos / Marginal microleakage of bulk fill and nanohybrid resins in deciduous teeth

Introducción: En la atención odontológica a niños es crucial seleccionar materiales restaurativos con buen rendimiento clínico y corto tiempo de aplicación, especialmente en pacientes con capacidad de atención limitada. Las resinas compuestas, con el mejoramiento de sus propiedades físicas y mecánicas, constituyen hoy uno de los materiales de mayor elección por el odontopediatra. Las resinas de relleno masivo son una alternativa atractiva para las restauraciones en el sector posterior. Objetivo: Comparar el grado de microfiltración marginal de resinas de relleno masivo y nanohíbrida en molares deciduos. Métodos: Estudio experimental, in vitro, en cuarenta molares deciduos; exodonciados por motivos terapéuticos, divididos en dos grupos. Grupo I: resina nanohíbrida con técnica incremental (Tetric® N Ceram - Ivoclar Vivadent) y Grupo II: resina de relleno masivo con técnica monoincremental (Tetric® N Ceram bulk fill - Ivoclar Vivadent). Se realizó un proceso de termociclado manual de 500 ciclos, entre 5 ºC ± 2 ºC y 55 ºC ± 2 ºC. Las muestras fueron sumergidas en azul de metileno al 0,5 por ciento durante 24 horas a 37 ºC. Se analizaron con el microscopio estereoscópico de luz a 40X. Resultados: Todas las muestras presentaron microfiltración. Con el uso de resina nanohíbrida, el 25 presentó microfiltración leve; el 30 por ciento, moderada; y el 45 por ciento, severa. En el grupo de la resina de relleno masivo, el 30 por ciento presentó microfiltración leve; el 35 por ciento, moderada; y el 35 por ciento, severa. No se encontró diferencia significativa entre ambos grupos (p = 0,55). Conclusiones: Ambas resinas, de relleno masivo y nanohíbrida, presentaron similar microfiltración marginal in vitro, en molares deciduos; por lo que la técnica de relleno masivo, por su fácil y rápida aplicación en un solo tiempo, es una buena alternativa en la rehabilitación dental odontopediátrica(AU)

Introduction: In children's dental care it is crucial to select restorative materials of proven clinical quality and a short application period, particularly with patients of limited attention capacity. Due to their improved physical and mechanical properties, composite resins are currently one of the materials of choice for children's dental care. Bulk fill resins are an attractive alternative for posterior restorations. Objective: Compare the degree of marginal microleakage of bulk fill and nanohybrid resins in deciduous teeth. Methods: An experimental in vitro study was conducted of 40 deciduous teeth extracted for therapeutic reasons, which were divided into two groups. Group I: nanohybrid resin by incremental technique (Tetric® N Ceram - Ivoclar Vivadent) and Group II: bulk fill resin by monoincremental technique (Tetric® N Ceram bulk fill - Ivoclar Vivadent). A manual 500-cycle thermocycling procedure was performed at 5ºC ± 2ºC to 55ºC ± 2ºC. The samples were soaked in 0.5 percent methylene blue at 37ºC for 24 hours and analyzed under a light stereo microscope at 40X. Results: Microleakage was present in all the samples. In the nanohybrid resin group, microleakage was mild in 25 percent, moderate in 30 percent and severe in 45 percent. In the bulk fill resin group, microleakage was mild in 30 percent, moderate in 35 percent and severe in 35 percent. No significant difference was found between the groups (p = 0.55). Conclusions: Both resins, bulk fill and nanohybrid, presented similar in vitro marginal microleakage in deciduous molars. The bulk fill technique is therefore a good alternative for children's dental rehabilitation, due to its easy and fast application in a single session(AU)

In vitro three-dimensional organotypic culture models of the oral mucosa.

Three-dimensional, organotypic models of the oral mucosa have been developed to study a wide variety of phenomena occurring in the oral cavity. Although a number of models have been developed in academic research labs, only a few models have been commercialized. Models from academic groups offer a broader range of phenotypes while the commercial models are more focused on the oral and gingival mucosa. The commercialized models are manufactured under highly controlled conditions and meet the requirements of quality standards, which leads to high levels of reproducibility. These in vitro models have been used to evaluate the irritancy of oral care products such as toothpastes, mouthwashes, and mucoadhesives. The effects of cigarette smoke on oral cavity tissues have been studied and compared to those of e-cigarettes. Oral tissue models have facilitated investigation of the mechanisms of oral mucositis and oral candidiasis and have been used to examine transbuccal drug delivery rates and the absorption of nanoparticles. Infection studies have investigated the effects of HIV-1 along with the effects of commensal and pathogenic bacteria. More recently, a differentiated oral tissue model has been shown to express the ACE2 receptor, which is known to be important for the receptor-mediated entry of the SARS-CoV-2 coronavirus into human cells and tissues. Hence, oral mucosal models may find application in determining whether viral infection of the oral mucosa is possible and whether such infection has implications vis-a-vis the current COVID-19 pandemic. As is apparent, these models are used in a broad variety of applications and often offer advantages versus animal models in terms of reproducibility, avoiding species extrapolation, and the ethical concerns related to human and animal experimentation. The goals of this paper are to review commercially available models of the human buccal and gingival mucosa and highlight their use to gain a better understanding of a broad range of phenomena affecting tissues in the oral cavity.

Higher Prevalence of Nickel and Palladium Hypersensitivity in Patients with Ulcerative Colitis.

BACKGROUND: The etiology of ulcerative colitis (UC) remains elusive even though many genetic and environmental pathogenic factors have been reported. Aberrant inflammatory responses mediated by specific subsets of T cells have been observed in ulcerative lesions of UC patients. OBJECTIVES: To elucidate the involvement of a delayed-type hypersensitivity reaction in UC, we focused on dental metal hypersensitivity, a T cell-mediated, delayed-type allergic reaction that causes oral contact mucositis and systemic cutaneous inflammation. METHOD: We recruited 65 Japanese UC patients and 22 healthy controls (HC) and used the in vitro lymphocyte stimulation test to quantify their sensitivity to zinc, gold, nickel, and palladium - the metals that have been widely used in dentistry. All subjects were users of metallic dental implants and/or prostheses containing zinc, gold, nickel, and/or palladium as major constituents. RESULTS: Sixty percent of the UC patients were hypersensitive to at least one metal species, whereas 32% of the HC were hypersensitive to only a single metal species. The overall incidence of metal hypersensitivity was significantly higher for UC patients than for HC. Furthermore, a significantly greater proportion of UC patients were hypersensitive to nickel or palladium. The severity of the sensitivity to nickel and palladium was also significantly greater for UC patients than for HC. CONCLUSIONS: This pilot study demonstrates that UC patients have a significantly higher incidence of hypersensitivity to nickel and palladium, suggesting the possible involvement of dental metal hypersensitivity in UC pathogenesis.

Comportamento biomecânico e sobrevivência de coroas de cerâmica híbrida implanto- suportadas confeccionadas por diferentes técnicas / Biomechanical behavior and survival of implant-supported hybrid ceramic crowns made by different techniques

O presente estudo teve como objetivo investigar a probabilidade de sobrevivência e distribuição de tensão de restaurações de cerâmica infiltrada por polímero sobre implantes. Setenta e cinco coroas suportadas por implantes foram divididas de acordo com a técnica de fabricação, usando uma base de titânio(Tibase): CME - Solução protética de duas peças composta por uma coroa cimentada no pilar híbrido (Tibase + mesoestrutura cerâmica); MC - Solução protética de peça única composta por uma coroa cimentada diretamente sobre o Tibase; e MP - Solução protética de peça única composta por uma coroa cimentada em um Tibase com orifício de acesso para parafuso. Todas as coroas foram fadigadas pelo teste stepwise (intervalo de carga de 50 N a cada 20.000 ciclos até 1200 N e 350.000 ciclos). As coroas falhadas foram inspecionadas sob microscopia eletrônica de varredura e a probabilidade de sobrevivência foi analisada usando os testes Log-Rank e Willcoxon. Uma geometria tridimensional de cada grupo foi modelada e analisada pelo método dos elementos finitos. Resultados de deformação total, tensão de von-Misses, tensão principal máxima e microdeformação foram solicitados sob carga axial de 900 N. Log-Rank (p = 0,17) e Willcoxon (p = 0,11) revelaram uma probabilidade de sobrevivência semelhante entre as técnicas de fabricação sob 300 e 900 N. Independentemente da sobrevivência semelhante entre CME e MC, MP mostrou resistência característica superior e menor variação de dados. Maior concentração de tensão foi observada no perfil de emergência da coroa independente do grupo. A fractografia possibilitou identificar que a direção de propagação de trinca ocorreu da cervical para oclusal. É possível concluir que a sobrevivência de uma restauração implanto-suportada com cerâmica vítrea infiltrada por polímero independe da técnica utilizada para sua confecção; e que a região do perfil de emergência da coroa protética sempre deve ser avaliada nas consultas periódicas devido a grande prodominância de falhas nessa área(AU)

The present study aimed to investigate the survival probability and the stress distribution of a polymer infiltrate ceramic restorations cemented on a chairside titanium­base manufactured using different techniques. Seventy-five implant-supported crowns were divided according to the manufacturing technique using a chairside titanium­base: CME - Two-piece prosthetic solution composed by a crown cemented on the hybrid abutment; MC - One-piece prosthetic solution composed by a crown direct cemented on a titanium base; and MP - One-piece prosthetic solution composed by a crown cemented on a Tibase with screw access hole. All crowns were staircase fatigued (load step of 50 N in each 20,000 cycles until 1200 N and 350,000 cycles). The failed crowns were inspected under scanning electron microscopy. And the survival probability using Log-Rank and Willcoxon tests. One threedimensional geometry from each group were modeled and analyzed using the finite element method. Results in total deformation, von-Misses stress, maximum principal stress and microstrain were requested under 900 N axial load. Log-Rank (p = 0.17) and Willcoxon (p = 0.11) revealed similar survival probability between the techniques at 300 and 900 N. Regardless of the similar survival between CME and MC, MP showed superior characteristic strength and less data variation. Higher stress concentration was observed in the emergence profile of the crown regardless the group design. Fractography analysis allowed to identify that the crack propagation direction occurred from cervical to occlusal. It is possible to conclude that the survival of an implant-supported restoration with polymer infiltrated ceramic network is not influence by the technique used to make it; and that the emergence profile of the prosthetic crown must always be evaluated due to the great incidence of failures in this area(AU)

Effect of the manual manipulation of composite resin with latex gloves / Efecto de la manipulación manual de resina compuesta con guantes de látex

Purpose: This in vitro study aimed to evaluate the influence of the manual manipulation of two composite resins: Filtek™ Z350XT (3M ESPE) and Herculite Précis® (Kerr), with latex gloves contaminated with powder, human saliva and alcohol, on the microhardness values. Material and Methods: Manual manipulation was evaluated using latex gloves with powder, latex gloves without powder, latex gloves without powder with saliva, latex gloves without powder with alcohol, and without hand manipulation or contaminants (control). Each resin was manually manipulated for 10 seconds and photoactivated for 20 seconds with a light intensity of 1000mW/cm2 using a VALO ­Ultradent LED light­ cured unit, and then each sample was evaluated on the microhardness Vickers tester Leitz (Wetzlar). The collected data were analyzed using Kruskal ­Wallis and Mann ­ Whitney post-test (p<0.05). Results. Microhardness values showed a significant difference between the evaluated and control groups, showing lower microhardness values in the group of latex glove with powder for Filtek™ Z350XT and the group of latex glove without powder with saliva for Herculite Précis®. Conclusion. The manual manipulation of composite resins decreases their surface microhardness.

Propósito: Este estudio in vitrotuvo como objetivo evaluar la influencia de la manipulación manual de dos resinas compuestas: Filtek ™ Z350XT (3M ESPE) y Herculite Précis® (Kerr), con guantes de látex contaminados con polvo, saliva humana y alcohol, sobre los valores de microdureza. Material y Métodos: La manipulación manual se evaluó utilizando guantes de látex con polvo, guantes de látex sin polvo, guantes de látex sin polvo con saliva, guantes de látex sin polvo con alcohol, y sin manipulación manual o contaminantes (control). Cada resina fue manipulada manualmente durante 10 segundos y fotoactivada durante 20 segundos con unaintensidad de luz de 1000mW/cm2 usando una unidad de fotocuración LED VALO - Ultradent, y luego cada muestra fue evaluada en el tester de microdureza Vickers Leitz (Wetzlar). Los datos recopilados se analizaron utilizando Kruska ­Wallis y post-test Mann­ Whitney (p<0.05). Resultados: Se observó una diferencia significativa en los valores de microdureza entre los grupos evaluados y el grupo control, con valores más bajos de microdureza en el grupo de guantes de látex con polvo para Filtek™ Z350XT y el grupo de guantes de látex sin polvo con saliva para Herculite Précis®. Conclusión. La manipulación manual de resinas compuestas disminuye su microdureza superficial.

Analysis of nine cases of oral foreign body granuloma related to biomaterials.

Foreign bodies can penetrate the interior of soft and, sometimes, hard, tissues in various ways, including through open wounds, lacerations and traumatic accidents. However over the years, evidence of links between the use of dental materials and lately, significant involvement of aesthetic filler materials as foreign bodies in the oral and perioral region have been reported. Foreign body granulomas (FBGs) may develop from this exogenous material, histopathologically characterized by the presence of chronic inflammation and a high amount of macrophages. This study presents nine FBG cases affecting the oral and perioral regions, and carries out a literature review on the main clinical, histopathological and material characteristics used in dental and dermatological procedures related to the appearance of this type of granuloma.

Allergic reactions in oral and perioral diseases-what do allergy skin test results show?

OBJECTIVE: The aim of this study was to examine potential allergic reactions to different materials in oral and perioral diseases. STUDY DESIGN: The study included 230 consenting subjects in total-180 patients with oral and perioral diseases (30 patients each in the following groups: angioedema, oral lichenoid reactions [OLRs], burning mouth syndrome [BMS], gingivostomatitis, cheilitis, and perioral dermatitis) and 50 healthy controls. Comprehensive diagnostic workups were performed prior to patch testing with standard series allergens and with specific dental materials and skin prick testing (SPT) for food, preservatives and additives, and inhalants. RESULTS: Positive allergy test results were more common in patients with oral diseases than in controls, with significantly greater frequency of contact allergies in the cheilitis group (P = .048). The most common allergens in the majority patients were cobalt chloride (13.3% in BMS vs 10% in controls) and nickel sulfate (10% in gingivostomatitis and 6.7% in cheilitis vs 3.3% in controls), and preservatives (23.3% in angioedema and BMS). CONCLUSIONS: Allergy skin tests are reliable and justified for diagnosing allergies in cases of persistent or recurrent oral diseases. This is the only way to confirm allergies and is the basis for consequent allergen avoidance for the benefit of the patient.

Processamento de vitrocerâmicas a base de dissilicato de lítio com gradiente funcional de porosidade / Processing of glass-ceramic based of lithium disilicate with functional gradient of porosity

O desempenho das cerâmicas odontológicas é um aspecto bastante explorado na literatura, uma vez que o aprimoramento das suas características permite desenvolver materiais com maior longevidade. Trincas, delaminações, lascamentos e fraturas catastróficas são as falhas mais encontradas em restaurações cerâmicas. O objetivo dessa pesquisa foi conhecer o comportamento mecânico de coroas monolíticas gradadas e avaliar a possibilidade de produzir uma vitrocerâmica experimental a base de dissilicato de lítio com gradiente funcional de porosidade. Este trabalho foi dividido em duas partes: a primeira, teórico/computacional e a segunda, a fabricação do produto. 1) Através de software CAD foi modelado um molar inferior com preparo tradicional para coroa total e uma coroa total monolítica com camada de cimento resinoso entreposto. Quatro grupos foram compostos pela variação da composição das coroas totais: Coroa rígida (E=80 GPa), flexível (E=30 GPa), gradação bioinspirada (de 80 até 30 GPa) e gradação inversa (de 30 até 80 GPa). O modelo foi exportado para o software de análise. Os materiais foram considerados isotrópicos, linearmente elásticos e homogêneos, com contatos ideais. Uma força de 300N foi aplicada na face oclusal, a base do modelo foi fixada em todas as direções. A tensão máxima principal, tensão de Von-Mises e deslocamento foram utilizadas para observar o comportamento mecânico. 2) Uma mistura de óxidos foi homogeneizada e submetida à fusão. As fritas obtidas por resfriamento foram moídas e passaram por diferentes tratamentos térmicos, seguido das análises de DSC e DRX. Seis grupos experimentais foram obtidos: DL-E (vitrocerâmica densa a base de dissilicato de lítio simulando esmalte); DL-D (vitrocerâmica densa a base de dissilicato de lítio simulando dentina); DLGrad (vitrocerâmica gradada a base de dissilicato de lítio); YTZP-E (vitrocerâmica densa reforçada por YTZP simulando esmalte); YTZP-D (vitrocerâmica densa reforçada por YTZP simulando dentina); YGrad (vitrocerâmica gradada reforçada por YTZP). Suspensões aquosas contendo 23 e 30%-vol. de pó de vidro foram preparadas e submetidos à técnica de gel casting para formar um gradiente funcional. As vitrocerâmicas com e sem gradiente funcional de porosidade foram caracterizadas pelas técnicas de DRX, FEG, densidade e porosidade aparentes. Também foram realizados ensaios mecânicos de resistência à flexão biaxial e fractografia. Os resultados obtidos foram estatisticamente avaliados por Anova 1 fator e Tukey (p<0,05). As micrografias mostraram formação de gradiente funcional de porosidade apenas nas vitrocerâmicasa base de dissilicato de lítio. Não houve diferença entre as densidades de todos as vitrocerâmicas estudadas, porém YTZP-E, YTZP-D e YTZP-Grad apresentaram porosidade 10% maior do que as vitrocerâmicassem zircônia. Os defeitos críticos na superfície das vitrocerâmicas são semelhantes em todas condições estudadas, porém a aleatoriedade de poros internos das vitrocerâmicas contendo YTZP proporcionaram diminuição da resistência à flexão, com diferença estatisticamente significante em relação às vitrocerâmicas sem YTZP. Entre as vitrocerâmicas densas e gradadas não houve diferença na resistência à flexão. Conclui-se que a adição de zircônia em sistema a base de SiO2-Li2O alterou a temperatura de sinterização, o padrão de porosidade, a resistência flexural e comprometeu a formação do gradiente funcional de porosidade. O comportamento mecânico das vitrocerâmicas à base de dissilicato de lítio densas e gradadas são similares(AU)

The performance of dental ceramics is very explorated at literature, once the enhancement of yours features allow the development of materials with higher longevity. Cracks, delamination, chipping and catastrophic fracture are the faillures most finds at ceramics restorations. The aim of this research was knew the mechanical behavior of monolithics graded crows and it was evaluated the possibility to produce a glass ceramic based of lithium disilicate with gradient of porosity. This research was divided into two parts: the first one, theoretical computational and the second, the manufacturing product. 1) Using a CAD software, a lower molar received a full-crown preparation. The monolithic crown was modeled with a resin cement layer of 0.1 mm. Four groups were distributed according to the full crown elastic modulus (E):(a)Bioinspired crown with regressive elastic gradation (from 80 to 30 GPa); (b) Crown with regressive elastic gradation (from 30 to 80 GPa); (c) Rigid crowns and (d) Flexible crown. The model was exported to the analysis software and meshed into 385,240 tetrahedral elements and 696,310 nodes. Materials were considered isotropic, linearly elastic, and homogeneous, with ideal contacts. A 300-N load was applied at the occlusal surface and the base of the model was fixed in all directions. The results were required in Maximum principal stress, Von-Mises Stress and Displacement. 2) A mixture of oxides was homogenized and it was melted at fusion. The glass frits get by cooling were grinded and passed through heat treatment accordin to CSD and RXD. Six groups were obtained: DL-E (glass ceramic dense based of lithium disilicate simulating enamel); DL-D (glass ceramic dense based of lithium disilicate simulating dentin); DL-Grad (glass ceramic graded based of lithium disilicate); YTZP-E (glass ceramic dense reforced by YTZP simulating enamel); YTZP-D (glass ceramic dense reforced by YTZP simulating dentin); YTZP-Grad (glass ceramic graded and reforced by YTZP). Twenty-three and 40% of glass powder were prepared through dispersion water and it was submitted for techinique of gel casting to form functional gradient. The samples with and without functional gradient of porosity were characterized by RXD, FEG, density of all the groups, however YTZP-E, YTZP-D and YTZP-Grad showed porosity 10% greater the groups without zirconia. The critical flaw at surface of the ceramics were similar to the groups, however the random of internal pores at groups with YTZP get the flexural strength lower, with statistical difference with the groups without YTZP. Among the dense and graded groups were not statistical differences at flexural strength. It concluded that add of zirconia at ceramic system based of SiO2-Li2O changed the temperature of sintering, the standard of porosity, flexural strength and compromised the development of functional gradient of porosity. The mechanical behavior of ceramics based at lithium disilicate dense and graded were similar(AU)

Five hundred patients reporting on adverse effects from dental materials: Frequencies, complaints, symptoms, allergies.

OBJECTIVE: Information on patients with real or claimed adverse reactions towards dental materials in large patient cohorts is rare. Therefore, the aim of the present study was to investigate patients reporting on complaints and symptoms to dental materials over a 16-year period. METHODS: Five hundred patients were characterized by one single dental team regarding age and sex distribution, subjective complaints and objective intraoral symptoms, and allergy status relevant to dental materials. RESULTS: Elder patients and females predominated. Subjective complaints were reported by 490 patients, ranging from 1 to 12 complaints per patient. Most often, burning mouth (44%), tooth-/jawache (22%) and dry mouth (20%) were reported. In 54% no objective intraoral symptom was diagnosed. The main objective intraoral symptoms were tongue anomalies (lingua plicata or geographica; 14%), gingivitis adjacent to restorations (12%), redness of the palate or the edentulous ridge (7%), oral lichen planus (6%), grayish discolorations, lichenoid contact lesions, and leukoplakia (<5%). Patch testing of 416 (83%) patients revealed that allergy was diagnosed as contributing to the complaints or symptoms in 70 (14%) patients with metals being the most frequent allergens. Gingivitis adjacent to restorations (3.2%), redness of the palate or edentulous ridge (1.4%) and whitish lichen-like lesions (1.8%) were associated to allergy from dental materials. SIGNIFICANCE: The high number of subjective complaints per patient and their wide variety suggests that most patients seriously suffered. Furthermore, the fact that only 46% of the patients had objective intraoral symptoms demands for an interdisciplinary collaboration to elucidate other than dental causes.

Harmful consequences of specific substances on the oral health.

Numerous substances may have an adverse influence on the oral region by virtue of their potentially harmful effects. Dental practitioners are often the first to see these effects in the head and neck region. Knowledge of the damaging consequences of agents such as alcohol, tobacco, areca nut, medications, alcohol-containing mouthwashes, dental devices and materials can assist the practitioners in clinical decision-making and accurate diagnosis of associated lesions. More importantly, timely diagnosis and prompt reporting of such harmful effects improve the quality of care. Such knowledge may also help in patient's education for the avoidance of associated adverse effects (AEs). Consequently, a thorough acquaintance of AEs will consolidate the distinct role of medical and oral health practitioners in safeguarding the patients' oral and systemic well-being. This article was planned to review the harmful consequences of specific substances on the oral health. Traditionally, the emphasis of review articles has been on reviewing the harmful effects of a single entity on oral health. This review is unique in the sense that it comprehensively and collectively focussed on the harmful effects on the oral health of addictive and illicit substances (alcohol, betel nut), medications, alcohol-containing mouthwashes, medications and dental materials.

Dental patch testing in patients with undifferentiated oral lichen planus.

BACKGROUND/OBJECTIVES: Distinguishing between oral lichen planus (LP) and lichenoid reactions to dental restorations can be impossible on clinical and histopathological grounds. Epicutaneous patch testing is an investigation that may guide patients and physicians in making timely and costly decisions to replace or cover existing dental restorations. This study aimed to assess the role of epicutaneous patch testing with a battery of dental allergens in patients with undifferentiated oral LP. METHODS: A retrospective review of the medical records of patients with biopsy-proven oral LP referred by an oral medicine specialist and who presented for dental epicutaneous patch testing at a dermatology clinic in Perth, Western Australia between 2009 and 2016 was performed. RESULTS: In total, 68 patients were included, of whom 54 (79%) had positive patch tests. Gold 26 (48%), mercury 24 (44%), nickel 22 (41%), copper 19 (35%), potassium dichromate 14 (26%) and methylhydroquinone 13 (24%) were the most common allergens for which patients tested positive. Hypothyroidism and non-steroidal anti-inflammatory drugs were associated with negative patch tests (P = 0.01 and 0.04, respectively). Smoking history, other medications and comorbidities, the location of the dental restorations and unilateral or bilateral disease were not significantly associated with the patch test results. Restorations were removed in 23 patients: 21 of these (91%) had positive epicutaneous patch tests. Of the 20 patients followed up, 19 (95%) experienced some improvement, among whom 11 (58%) had complete remission. CONCLUSION: Epicutaneous patch testing disclosed a high proportion of relevant positives. This guided the clinical decision to change dental restorations, with high rate of clinical improvement.

Influence of dental materials on cells of the equine periodontium.

BACKGROUND: Therapy for equine periodontal disease can include filling of the periodontal pockets and widened interproximal spaces. Recommended dental materials are generally adopted from human dentistry. OBJECTIVES: To evaluate the biocompatibility of dental materials for equine periodontal fillings in vitro. STUDY DESIGN: In vitro experiments. METHODS: Four different dental materials (PeriCare® , Provicol® , Calxyl® and Honigum) were tested on equine periodontal fibroblasts. Possible cytotoxic effects were assessed microscopically and by MTT assay, and the expression of inflammatory marker genes was measured by qRT-PCR. RESULTS: PeriCare® and Provicol® had no effects on the cells, whereas Honigum and Calxyl® were associated with severe cytotoxic effects. MAIN LIMITATIONS: The results of this in vitro study need to be confirmed by clinical studies. CONCLUSIONS: Before adapting dental materials from human dentistry, it is crucial to initially test them in a specific equine model.

Dental Technicians' Pneumoconiosis.

A 40-year-old female dental technician visited our hospital for the investigation of a chest X-ray abnormality. Chest computed tomography demonstrated centrilobular nodules and lung volume reduction, and her serum KL-6 level was elevated. A histological analysis of the specimens obtained on a surgical lung biopsy showed peribronchiolar fibrosis with pigmented macrophages and cholesterol clefts. An energy-dispersive X-ray analysis showed that these lung tissues contained some metals, including indium. The serum indium level was also elevated. We diagnosed this patient with pneumoconiosis caused by exposure to sandblasting certain dental metals. This is the first reported case of pneumoconiosis in a dental technician associated with exposure to indium.

Bacterial Contamination of Endodontic Materials before and after Clinical Storage.

INTRODUCTION: The aim of this study was to evaluate the bacterial contamination in endodontic consumables (gutta-percha points, rubber dams, paper mixing pads, caulking agents, and endodontic instrument sponges [EISs]) before and after clinical use and storage. METHODS: Materials were randomly sampled in triplicates at 3 time points (t0, at package opening; t1, at 7 days; and t2, at 14 days) during their clinical usage. The gutta-percha points and caulking agent (25 mg) were added to 1 mL phosphate-buffered saline (PBS). The rubber dam, paper mixing pad, and EIS were added to 25 mL PBS. After vortexing, centrifuging, and removing the supernatant, the pellet was resuspended in 1 mL PBS, plated on fastidious anaerobic agar, and incubated aerobically and anaerobically. The grown colonies were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The total bacterial load was calculated in the remaining volume (800 µL) from each sample by quantitative polymerase chain reaction after DNA extraction. RESULTS: All tested materials showed a varied number of contaminated samples at the 3 time points (except EIS at t0) using MALDI-TOF MS. The most isolated genera were Propionibacterium (42%) and Staphylococcus (32%). By using non-culture-based approaches, all tested materials at the 3 time points (except gutta-percha at t0 and the caulking agent at t0, t1, and t2) carried bacterial DNA. CONCLUSIONS: The majority of the tested materials harbored bacteria in their samples before and after clinical storage. Nosocomial infection derived from commonly used consumables could have an impact on the outcome of endodontic treatment.

Contact stomatitis.

Contact stomatitis occurs in up to 10% of the population. Mechanical or chemical irritation, ill-fitting dentures, and dental fillings can induce irritant contact stomatitis. Type I hypersensitivity and type IV hypersensitivity to dental products and foods are frequently responsible for the allergic types of contact stomatitis. We review the causal agents of contact stomatitis, the differential diagnoses, diagnostic testing, and potential treatment.

Genotoxicity Induced by Dental Materials: A Comprehensive Review.

Genotoxicity is the capacity of an agent to produce damage in the DNA molecule. Considering the strong evidence for a relationship between genetic damage and carcinogenesis, evaluation of genotoxicity induced by dental materials is necessary for elucidating the true health risks to patients and professionals. The purpose of this article was to provide a comprehensive review of genotoxicity induced by dental materials. All published data showed some evidence of genotoxicity, especially related to dental bleaching, restorative materials and endodontic compounds. Certainly, such information will be added to that already established for regulatory purposes as a safe way to promote oral healthcare and prevent oral carcinogenesis.

Symptomatic oral lesions may be associated with contact allergy to substances in oral hygiene products.

OBJECTIVE: Dental materials and oral hygiene products may be responsible for oral contact allergic reactions. We aimed to determine the occurrence of allergies in patients with symptomatic oral lichen planus (OLP), oral lichenoid lesions (OLLs) and stomatitis and investigate if patch testing could identify contact allergies to dental materials and oral hygiene products in these patients. METHODS: Forty-nine patients (7 men, 42 women) aged 31 to 77 years (61 ± 10.3 years) with symptomatic OLP, OLL or stomatitis and 29 healthy age- and gender-matched control subjects were included. They underwent an interview, clinical examination, oral mucosal biopsy and epicutan testing to the European baseline series, a toothpaste and dental material series. RESULTS: Nineteen patients had OLP, 19 OLL and 11stomatitis. Oral burning/itching was the most common symptom (83.7%), and 65.3% patients had more than one symptom. Patients visited their dentist more often than the healthy subjects and had statistically higher DMF-T and DMF-S scores. Nineteen patients (38.8%) and 10 healthy control subjects (34.5%) had allergic contact reactions primarily to fragrance ingredients. No differences could be found between OLP, OLL, stomatitis and healthy controls with regard to allergic contact reactions. However, contact allergy to aroma substances differed significantly between the patients and the healthy control subjects (p = 0.02). This type of contact allergy was most common in patients with OLP and OLL (p = 0.01). Avoidance cleared symptoms in all cases. CONCLUSION/CLINICAL RELEVANCE: Allergic reactions to aroma substances in oral hygiene products are common in patients with symptomatic OLP, OLL and stomatitis.

Técnicas para reduzir os efeitos da contração de polimerização das resinas compostas fotoativadas / Techniques for reducing the effects of polymerization shrinkage of composites photoactivated resins

Introdução: uma complicação inerente a todas as resinas compostas é o stress gerado pela contração de polimerização. As resinas compostas da atualidade, após a polimerização, perdem entre 2% a 3% de todo o seu volume. Essa perda pode acarretar em alterações fortemente comprometedoras a nível micro e macroscópico. Objetivo: abordar a importância do uso de técnicas e manobras clínicas, que visam diminuir a contração de polimerização das resinas compostas, reduzindo seus efeitos na cavidade, para que se tenha um procedimento restaurador com elevado índice de sucesso clínico e boa aceitação pelos pacientes. Material e Métodos: foi realizada uma revisão da literatura por meio de uma busca bibliográfica nas seguintes bases de pesquisa online: PUBMED/MEDLINE, LILACS, BBO e SCIENCE DIRECT, através do rastreio de artigos relevantes publicados entre o período de 2000 a 2015. Resultados: comparando as formas de ativação dos compósitos, os compósitos fotopolimerizáveis possuem um menor escoamento e maior stress de contração se comparados a compósitos com ativação química, isso se dá devido à fotoativação que se destaca por ser uma reação rápida quando comparada a outros métodos, não dispondo de tempo para a resina se acomodar na cavidade e ter uma boa interação com o sistema adesivo previamente aplicado, levando a grande parte dos problemas clínicos das restaurações. Conclusão: questionamentos sobre os efeitos da contração de polimerização, ainda não foram completamente elucidados no meio científico, por isso algumas técnicas como a escolha de fotopolimerizadores a LED, manutenção da fase pré gel, manutenção do Fator C e técnica de inserção incremental, podem ser usadas para minimizar os efeitos dessa contração nas restaurações feitas com resina, afim de reduzir insucessos como, sensibilidade pós operatória, infiltração marginal e riscos de agressão pulpar levando a uma maior longevidade dos procedimentos restauradores com materiais resinosos. (AU)

Introduction: a complication inherent in all composite resins is the stress generated by the polymerization contraction. The present composite resins, after polymerization, lose between 2% and 3% of their entire volume. This loss can lead to strongly compromising micro and macroscopic changes. Objective: to address the importance of using technical and clinical maneuvers, which aim to reduce polymerization shrinkage of composite resins, reducing its effects in the cavity, in order to have a restorative procedure with high clinical success rate and good patient acceptance. Material and Methods: a review of the literature through a literature search in the following search online databases was performed: PubMed/MEDLINE, LILACS, BBO and SCIENCE DIRECT, through the screening of relevant articles published between 2000 to 2015. Results: comparing both activation of composites, the dental composites have a lower flow and higher stress of contraction compared to composites with chemical activation, this is the due to photoactivation that stands out for being a quick reaction when compared to other methods, not providing time for the resin to settle in well and have a good interaction with the previously applied adhesive system, leading to much of the clinical problems of restorations. Conclusion: questions about the effects of polymerization shrinkage have not been fully elucidated in the scientific community, so some techniques such as the choice of curing lights to LED, the pre gel phase maintenance, maintenance of Factor C and incremental insertion technique can It is used to minimize the effects of this contraction in restorations made with resin in order to reduce failures as post-operative sensitivity, microleakage and pulp assault risks leading to increased longevity of restorative procedures with resinous materials. (AU)

Análise morfoestrutural de biomateriais para auxílio no processo de identificação humana / Morphostructural analysis of biomaterials for assistance in the human identification process

O objetivo do estudo foi avaliar as alterações de biomateriais restauradores e protéticos submetidos a temperaturas elevadas para o estabelecimento de parâmetros físicos que auxiliem nos casos de identificação humana em corpos carbonizados. A amostra do estudo experimental in vitro foi composta por 40 corpos de prova dividida em quatro grupos: GI (corpos de prova de cimentos de iônomero de vidro químico), GII (amálgamade prata), GIII (resina composta híbrida) e GIV (liga de cobre alumínio). Os corpos de prova foram submetidosa temperaturas de 300°C, 500°C, 700°C e 900°C. Após a incineração, os biomateriais foram submetidos a análises macroscópicas sobre as modificações de estrutura, coloração, forma e estabilidade dimensional e os dados analisados pela Análise de Variância e teste de Dunn (p<0,05). Os dados obtidos demonstraram em relação à radiopacidade uma diferença estatisticamente significante para as médias de densidade radiográfica no GI entre as temperaturas 700°C e 900°C; GIV entre as temperaturas 300°C e 900°C; 500° e 900°C. O GII atingiu seu ponto de fusão à 700ºC com aspecto pulverulento e lojas isoladas de mercúrio a 900°C. O GIII apresentou mudança estrutural nas temperaturas à 700°C e 900°C. No GIV não se constatou modificações relevantes. Assim, pode-se coligir que a resina composta micro hibrida e o amálgama apresentam severas alterações morfoestruturais enquanto o ionômero de vidro e o cobre alumínio não sofrem mudanças significativas em suas características originais. As alterações sofridas pelos materiais fornecem dados relevantes para o auxilio no processo de identificação humana de corpos carbonizados.

The aim of this study was to evaluate the changes of restorative and prosthetic biomaterials subjected to high temperatures for the establishment of physical parameters that assist in cases of charred bodies in human identification. The sample of the experimental in vitro study was composed by 40 specimens divided into 4 groups: GI (specimens of cements of ionomer of chemical glass), GII(silver amalgam), GIII (hybrid composite resin) and GIV (copper alloy aluminum). The specimens were subjected to temperatures of 300°C, 500°C, 700°C and 900°C. After incineration the biomaterials were submitted macroscopic analysis on changes of structure, color, shape and dimensional stability and all data were analyzed by ANOVA and Dunn’s test (p <0.05). Regarding the radiopacity there was statistically significant difference for the mean radiographic density in GI temperatures within 700°C and 900°C; GIV temperatures within 300°C and 900°C, 500°C and 900°C. The GII has reached its melting point at 700ºC with powdery appearance and isolated stores of mercury at 900°C. The GIIIhad structural change at 700°C and 900°C. In GIV it not observed significant changes. Thus, one cangather that the micro hybrid composite resin and amalgam exhibit severe morpho structural changes while the glass ionomer aluminum and copper does not undergo significant changes in their original characteristics. The changes undergone by materials provide relevant data to aid in the identification process of human bodies charred.