Tissue reaction to Aroeira (Myracrodruon urundeuva) extracts associated with microorganisms: an in vivo study.

Based on aroeira's (Myracrodruon urundeuva) antimicrobial activity and a future trend to compose intracanal medication, the aim of this study was to assess in vivo inflamatory tissue response to the extracts by edemogenic and histological analysis containing inactivated facultative and anaerobic microorganisms. For edema quantification, eighteen animals were divided into three groups (n = 3, periods: 3 and 6 hours) and 0.2 mL of 1% Evans blue per 100 g of body weight was injected into the penile vein under general anesthesia. After 30 min the animals received a subcutaneous injection in the dorsal region of aqueous or ethanolic extract of aroeira or saline (control) containing inactivated bacteria. Samples were collected, immersed in formamide for 72h, and evaluated by spectrophotometry (630 m). For histological analysis, polyethylene tubes with the extracts were implanted in the dorsal of 30 male rats. Analysis of the fibrous capsule and inflammatory infiltrate were performed after 7 and 30 days. The aqueous extract group induced less edema in both postoperative periods compared to the other groups, but the differences were not significant (p > 0.05). Tissue repair was significantly better after 30 days than after 7 days (p < 0.01). The aqueous solution showed less inflammatory response than the ethanolic solution (p < 0.05), with tendency for better results than control after 7 days. After 30 days, the response to both extracts was similar to control. The aqueous and ethanolic aroeira extracts containing inactivated microorganisms showed a trend for better results than saline, even when associated with microorganisms, and facilitated the tissue repair process.

Tissue reaction to Aroeira (Myracrodruon urundeuva) extracts associated with microorganisms: an in vivo study

Abstract: Based on aroeira's (Myracrodruon urundeuva) antimicrobial activity and a future trend to compose intracanal medication, the aim of this study was to assess in vivo inflamatory tissue response to the extracts by edemogenic and histological analysis containing inactivated facultative and anaerobic microorganisms. For edema quantification, eighteen animals were divided into three groups (n = 3, periods: 3 and 6 hours) and 0.2 mL of 1% Evans blue per 100 g of body weight was injected into the penile vein under general anesthesia. After 30 min the animals received a subcutaneous injection in the dorsal region of aqueous or ethanolic extract of aroeira or saline (control) containing inactivated bacteria. Samples were collected, immersed in formamide for 72h, and evaluated by spectrophotometry (630 m). For histological analysis, polyethylene tubes with the extracts were implanted in the dorsal of 30 male rats. Analysis of the fibrous capsule and inflammatory infiltrate were performed after 7 and 30 days. The aqueous extract group induced less edema in both postoperative periods compared to the other groups, but the differences were not significant (p > 0.05). Tissue repair was significantly better after 30 days than after 7 days (p < 0.01). The aqueous solution showed less inflammatory response than the ethanolic solution (p < 0.05), with tendency for better results than control after 7 days. After 30 days, the response to both extracts was similar to control. The aqueous and ethanolic aroeira extracts containing inactivated microorganisms showed a trend for better results than saline, even when associated with microorganisms, and facilitated the tissue repair process.

Retention and processing methods of nasal prosthesis.

Patients with congenital malformations, traumatic or pathological mutilation and maxillofacial developmental disorders can be restored aesthetically and emotionally by the production and use of facial prostheses. The aim of this study was to review the literature about the retention and processing methods of facial prostheses, and discuss their characteristics. A literature review on Medline (PubMed) database was performed by using the keywords "maxillofacial prosthesis, silicone, esin, pigment, cosmetic, prosthetic nose", based on articles published from 1956 to 2010. Several methods of retention, from adhesives to the placement of implants, and different processing methods such as laser, CAD/CAM and rapid prototyping technologies have been reported. There are advantages and disadvantages of each procedure, and none can be classified as better compared to others.

Effect of thermocycling on hardness, absorption, solubility and colour change of soft liners.

OBJECTIVE: The effect of artificial ageing on the hardness, absorption, solubility, and colour of soft denture liners was investigated. MATERIALS AND METHODS: Liner materials based on acrylic resin (Trusoft) or silicone (Dentusil, Ufi Gel P, and Ufi Gel SC) were tested before and after 2000 thermal cycles. A total of 20 specimens of each material were tested. Half of the specimens were used for hardness and colour evaluation, and the remainder for absorption and solubility tests. The hardness evaluation was carried out using a Shore A durometer, while absorption and solubility tests were performed by storing samples in a desiccator and weighing daily until reaching constant mass (W1). After thermocycling, the samples were again weighed (W2) and dried (W3). Colour was measured using a spectrophotometer. Statistical analysis was performed using GraphPad InStat at the p < 0.05 level. RESULTS: Thermocycling significantly affected the hardness of the specimens. The Trusoft material exhibited the highest absorption (1.48 ± 0.48), solubility (1.26 ± 0.28), and colour change (3.92 ± 0.33), significantly different from the other materials. There were no significant differences among the silicones in terms of absorption, solubility, and colour change, except for the colour of Dentusil, which changed (0.83 ± 0.11). CONCLUSION: It can be concluded that silicone liners performed significantly better compared to acrylic resin.

Surface roughness analysis of four restorative materials exposed to 10% and 15% carbamide peroxide.

The aim of this study was to evaluate the effects of carbamide peroxide (CP) on surfaces of different restorative materials. Porcelain, composite resin, glass ionomer, and amalgam were analyzed in this study. Surface roughness (Ra) was measured before and after treatment with 10% and 15% CP. Fifteen percent CP increased Ra values in both the glass ionomer and amalgam subgroups, while 10% CP increased Ra values in the glass ionomer subgroup only. Changes in restorative material surfaces can be more severe when bleaching is completed without a clinician's supervision. Hence, thorough patient examinations must be done before, during, and after bleaching treatment.

Care and cleaning of maxillofacial prostheses.

Both the cleaning and care of the prosthesis are fundamental for maintaining its quality. Therefore, the aim of this study was to show the methods of cleaning and care the patient needs to take as regards the prosthesis and adjacent tissue, starting with correct instruction and training by the professional. It has been verified that among the materials for fabricating maxillofacial prostheses, silicone was considered the major retainer of microorganisms on its surface. Therefore, for cleaning prostheses, the use of water and neutral soap, as well as chlorhexidine, is recommended. As regards care of the adjacent tissues, it is recommended to remove the prosthesis before going to sleep, in addition to washing the prosthesis receptor tissues with water and neutral soap or with a mixture of hydrogen peroxide and water. Whereas for the mucosal surfaces of the ophthalmic cavity, cleaning with filtered and boiled water or physiological solution at least 3 times a day is recommended.

Finger prosthesis: the art of reconstruction.

Hand deformities affect aesthetics function of hand severely compromised and also cause psychological disturbances. This report describes the fabrication of a silicone finger prosthesis for a patient after an accident at work. The finger prosthesis was retained by a vacuum effect on the stump. The silicone material Silastic-MDX 44210 was used to provide function and aesthetics. The finger prosthesis offered psychological, functional and rehabilitative advantages for the patient. Restoring the natural appearance with the prosthesis eliminated the trauma generated by the dysfunction and represented an efficient psychological therapy.

Color stability after accelerated aging of two silicones, pigmented or not, for use in facial prostheses.

One of the greatest challenges faced by buccomaxillofacial prosthetists is to reproduce the patient's exact skin color and provide adequate esthetics. To reach this objective, professionals must use materials with easy characterization and that maintain color over long periods of time. The objective of this study was, thus, to evaluate the color stability of two types of silicones, Silastic 732 and Silastic MDX4-4210. Twenty-four test specimens were made from each type of silicone and were divided into a colorless group and groups intrinsically pigmented with ceramics, cosmetics or iron oxide. The specimens were submitted to an accelerated system of aging for non-metallic materials. Readings were carried out initially and after periods corresponding to 163, 351, 692 and 1,000 hours of aging, using a reflection spectrophotometer analysis, and color alterations were calculated by the CIE L*a*b* system. The data were submitted to variance analysis and Tukey's test at a 5% level of probability. The results demonstrated that, irrespective of the period of time analyzed, all the materials underwent some type of chromatic alteration (DeltaE > 0). The test specimens made with Silastic 732 and MDX4-4210, without pigmentation, presented the lowest color alteration values after 1,000 hours of aging. Of the pigments, ceramic presented the lowest color alteration values and cosmetic powder presented the highest values. Thus, it may be concluded that the materials without the incorporation of pigments presented similar color alteration values, and did not differ statistically. The cosmetic powder used in this study was the pigment that most altered the color of the test specimens.

Evaluation of hardness and colour change of soft liners after accelerated ageing.

INTRODUCTION: Soft liners have been developed to offer comfort to denture wearers. However, this comfort is compromised when there is a change in the properties of the material, causing colour change, solubility, absorption and hardening. These characteristics can compromise the longevity of soft liners. AIM: The aim of this in vitro study was to investigate the effect of ageing on both the hardness and colour change of two soft liners following accelerated ageing. METHODS: Two denture liners, one resin based (Trusoft, Bosworth, Illinois, USA) and one silicone based (Ufi Gel P, Voco GMBH, Cuxhaven, Germany), were tested in this study for both hardness (using the Shore A scale) and colour change (using the CIE L*a*b* colour scale), initially and after 1008 hours (6 weeks) of accelerated ageing. Statistical analysis was performed using the unpaired t-test with the Welch correction. RESULTS: These indicated that both materials increased in hardness and underwent colour change after accelerated ageing. The initial hardness of Trusoft was far lower than that of Ufi Gel P (18.2 Shore A units vs 34.8 Shore A units). However, for Trusoft the changes for both hardness (from 18.2 to 52.1 Shore A units) and colour change (16.85 on the CIE L*a*b* colour scale) were greater than those for Ufi Gel P, for which hardness changed from 34.8 to 36.5 Shore A units and the colour change was 5.19 on the CIE L*a*b* colour scale. CONCLUSIONS: Ufi Gel P underwent less hardness and colour change after accelerated ageing than Trusoft. On the other hand, the use of Trusoft may be preferable in cases where initial softness is a major consideration, such as when relining an immediate denture after implant surgery.

Visual evaluation of color stability after accelerated aging of pigmented and nonpigmented silicones to be used in facial prostheses.

OBJECTIVES: The objective of this study was to evaluate by a visual method of comparison the color stability of nonpigmented and pigmented facial silicones after accelerated aging. MATERIALS AND METHODS: Two kinds of silicones were used in this study; one specifically formulated for facial prostheses and the other an acetic silicone for industrial use. Twenty-four trial bodies were made for each silicone. These were divided into colorless and intrinsically pigmented groups: ceramic, make-up, and iron oxide. The groups were submitted to accelerated aging for nonmetallic materials. An initial reading and subsequent readings were made at 163, 351, 692, and 1000 hours using a visual method of comparison. The values were annotated in a spreadsheet by two observers, according to scores elaborated for this study. RESULTS: All groups presented color stability in the visual method. According to the results obtained and analyzed in this study, we can conclude that both silicones, Silastic 732 RTV and Silastic MDX 4-4210, behaved similarly, they can therefore be indicated for use in maxillofacial prosthesis. The time factor of aging influenced negatively, independently of the pigmentation, or lack of it, and of silicones and no group had visually noticeable alterations in any of the accelerated aging time, independently of the addition or not of pigments.

Influence of investment, disinfection, and storage on the microhardness of ocular resins.

PURPOSE: The longevity of an ocular prosthesis is directly related to the resistance to erosion of its material. The purpose of this study was to evaluate the effects of chemical disinfection and the method of investment on the microhardness of ocular prosthesis acrylic resin. MATERIALS AND METHODS: Thirty-two test specimen investments were obtained in two silicones. A segment was cut in each test specimen, and each specimen was fixed in an acrylic disk. The specimens were then polished and submitted to the first microhardness test before immersion in distilled water and incubation for 2 months. During this 2-month period, the specimens were immersed in a water bath at 37 degrees C and were disinfected daily; half were disinfected with neutral soap and the other half were disinfected with 4% chlorhexidine gluconate. After the storage phase and disinfection, a second microhardness test was performed. The surface microhardness values for the acrylic resins were submitted to ANOVA, followed by the Tukey test. RESULTS: The disinfection and the period of storage did not statistically influence the surface microhardness of the acrylic resin, independent of the method of investment of the specimens (Zetalabor or Vipi Sil). The investment of specimens with Zetalabor silicone presented a greater surface hardness, independent of the type of disinfection and the period of storage. CONCLUSIONS: Based on these results, we suggest that the microhardness of the resin evaluated was not influenced by the method of disinfection or the time of storage used and was affected only by the investment material.

Color stability after accelerated aging of two silicones, pigmented or not, for use in facial prostheses

One of the greatest challenges faced by buccomaxillofacial prosthetists is to reproduce the patient's exact skin color and provide adequate esthetics. To reach this objective, professionals must use materials with easy characterization and that maintain color over long periods of time. The objective of this study was, thus, to evaluate the color stability of two types of silicones, Silastic 732 and Silastic MDX4-4210. Twenty-four test specimens were made from each type of silicone and were divided into a colorless group and groups intrinsically pigmented with ceramics, cosmetics or iron oxide. The specimens were submitted to an accelerated system of aging for non-metallic materials. Readings were carried out initially and after periods corresponding to 163, 351, 692 and 1,000 hours of aging, using a reflection spectrophotometer analysis, and color alterations were calculated by the CIE L*a*b* system. The data were submitted to variance analysis and Tukey's test at a 5 percent level of probability. The results demonstrated that, irrespective of the period of time analyzed, all the materials underwent some type of chromatic alteration (ÄE > 0). The test specimens made with Silastic 732 and MDX4-4210, without pigmentation, presented the lowest color alteration values after 1,000 hours of aging. Of the pigments, ceramic presented the lowest color alteration values and cosmetic powder presented the highest values. Thus, it may be concluded that the materials without the incorporation of pigments presented similar color alteration values, and did not differ statistically. The cosmetic powder used in this study was the pigment that most altered the color of the test specimens.

Aspectos biomecânicos relacionados à prótese sobreimplante com cantiléver / Related biomechanics aspects in dental prosthesis implant-supported with cantilever

Diversos fatores podem afetar a biomecânica do complexo sistema prótese-implante e tecido ósseo circunjacente das próteses implanto-suportadas com extensão distal. Desta forma, o presente trabalho discute alguns aspectos relacionados com a biomecânica de próteses sobreimplantes com cantiléver, como: o comprimento da extensão distal, comprimento do implante, design da barra metálica e dentição antagonista.

Pigmentação de próteses bucomaxilofaciais / Pigmentation of maxillofacial prostheses

Esta revisão de literatura traz informações a respeito do uso de diversos tipos de pigmentos que podem ser usados em próteses bucomaxilofaciais, assim como sua relação com os materiais empregados na confecção da prótese. Estas informações incluem alguns tipos de pigmentos (óxidos minerais, incorporados a componentes acrílicos, porcelanizados, oleosos, e outros) assim como os materiais que podem ser pigmentados, como silicone e resina acrílica, técnicas e características de cada material e tipo de pigmento. Em busca de melhores resultados não apenas na estética e longevidade das próteses, como também na manutenção das propriedades dos materiais e pigmentos, são estudados os fatores que podem causar a deterioração das mesmas, destacando a exposição à luz ultravioleta e as mudanças de condição ambiental, além da utilização de escalas de cores pré-fabricadas que facilitariam a confecção dessas próteses, permitindo economia de tempo e de material no momento da seleção da cor. Contudo, foi observado que as propriedades físicas e mecânicas do material utilizado podem variar de acordo com a adição dos pigmentos, sendo que a pigmentação extrínseca pode resultar em menor descoloração em relação à pigmentação intrínseca. Além disso, a instabilidade de cor dos materiais podem estar relacionados com vários fatores, tendo destaque a exposição à luz ultravioleta e as mudanças de condição ambiental.

This literature revision brings information regarding the use of several types of pigments that can be used in maxillofacial prostheses, as well as your relationship with the employed materials in the making of the prosthesis. This information include some types of pigments (mineral oxides, incorporate to acrylic components, porcelain, oily, and other) as well as the materials that can be pigmented, as silicon and acrylic resin, techniques and characteristics of each material and pigment type. In search of better results not just in the aesthetics and longevity of the prostheses, as well as in the maintenance of the properties of the materials and pigments, they are studied the factors that can cause to deterioration of the same ones, emphasizing the exhibition to the ultraviolet light and the changes of environmental condition, besides the use of scales of prefabricated colors that would facilitate the making of those prostheses, allowing economy of time and of material in the moment of the selection of the color. However, it was observed that the physical and mechanical properties of the used material can vary in agreement with the addition of the pigments, and the extrinsic pigmentation can result in smaller fading in relation to the intrinsic pigmentation. Besides, the instability of color of the materials can be related with several factors, tends prominence the exhibition to the ultraviolet light and the changes of environmental condition.

Oclusão em prótese total / Dental occlusion in complete denture

Neste artigo os autores fazem uma revisão através da busca literária para entender melhor sobre as alterações ocorridas em um usuário de prótese total convencional e suas consequências ao sistema estomatognático, levando em consideração o tipo de oclusão e as fraturas que podem ocorrer nas próteses de acordo com a distribuição de estresse

In this article the authors make a review to better understand the alterations that may happen in a patient with conventional complete denture and also the result in the stomatognathic system. Considering different occlusion types and possible fractures the main factor to be evaluated is the stress distribution

Prótesis nasal de uso nocturno: presentacion de un caso / Night use nasal prosthesis: case report

Después de la cirugía oncológica, el paciente portador de tumor facial encuentra un desafío tan difícil como la propia enfermedad. Tal problema tiene que ver con la reducción de autoestima provocada por su nueva imagen corporal. Siendo así, el presente artículo describe una técnica de simple confección que puede solucionar problemas vividos por el paciente portador de prótesis nasal, sujetada mecánicamente por las gafas, pues por la noche el paciente se ve imposibilitado de usar ese aparato, por existir la posibilidad de estropearse. Para estos pacientes, la prótesis nasal de uso nocturno, a pesar de ser un aparato no estético se vuelve extremamente satisfactorio proporcionando así una mejoría significativa en la cualidad de vida de estos pacientes

After an oncological surgery, a patient who has a facial tumor encounters a challenge as hard as his own illness. This problem is related to the reduction of his self-esteem, caused by his new body image. Therefore, the following article describes a simple technique that may solve problems experienced by the patient that wears nasal prosthesis mechanically retained to glasses. During his rest, the patient is unable to normally wear his prosthesis because of the risk of breaking them up. For those patients, the night-wear prosthesis, in spite of not being an esthetical prosthesis, becomes extremely satisfying, thus providing a improvement in his quality of life

O uso da termociclagem na avaliação da absorção, solubilidade, dureza e alteração de cor de reembasadores resilientes / The use of thermocycling on the evaluation of absorption, solubility, hardness and colour change of soft liners

Este estudo teve como objetivo avaliar a absorção, solubilidade, dureza e alteração de cor de reembasadores resilientes após termociclagem. Foram utilizados 4 materiais reembasadores resilientes, sendo 1 à base de resina (Trusoft) e 3 à base de silicone (Dentusil, Ufi Gel P e Ufi Gel SC). Foram confeccionadas 80 amostras no total, sendo que metade delas foi submetida ao teste de absorção e solubilidade e a outra metade, aos testes de dureza Shore A e alteração de cor. Todas as amostras foram submetidas à 2000 ciclos de termociclagem. O Dentusil apresentou os seguintes valores: Shore A (40,50); ΔE (0,83); absorção (0,30); solubilidade (0,01). Já o Trusoft apresentou os seguintes valores: Shore A (18,50); ΔE (3,92); absorção (1,48); solubilidade (1,26). O UfiGel P e SC apresentaram resultados semelhantes e intermediarios para os 3 testes. Portanto conclui-se que todas as propriedades estão intimamente relacionadas e que quanto maior for a dureza inicial do material, menor será a absorção e solubilidade e consequentemente menor será a alteração de cor

The purpose of this study was to investigate absorption, solubility, hardness and colour change of 4 soft liners after thermocycling. A resin base (Trusoft) and three silicone base (Dentusil, Ufi Gel P e Ufi Gel SC) were used on this research. A total of eighty samples were manufactured: forty for absorption and solubility test and forty for both hardness and colour change tests. All samples were subjected to 2000 hours of thermocycling. Dentusil showed the following values: Shore A hardness (40.50), colour change (ΔE=0.83), absorption (0.30) and solubility (0.01). Trusoft, on the other hand, showed the following values: Shore A hardness (18.50), colour change (ΔE=3.92), absorption (1.48) and solubility (1.26). Both UfiGel P and SC showed similar results for all three tests. All properties are linked and as big is the initial hardness, small will be both absorption and solubility and consequently small will be the colour change

O uso da termociclagem na avaliação da absorção, solubilidade, dureza e alteração de cor de reembasadores resilientes / The use of thermocycling on the evaluation of absorption, solubility, hardness and colour change of soft liners

Este estudo teve como objetivo avaliar a absorção, solubilidade, dureza e alteração de cor de reembasadores resilientes após termociclagem. Foram utilizados 4 materiais reembasadores resilientes, sendo 1 à base de resina (Trusoft) e 3 à base de silicone (Dentusil, Ufi Gel P e Ufi Gel SC). Foram confeccionadas 80 amostras no total, sendo que metade delas foi submetida ao teste de absorção e solubilidade e a outra metade, aos testes de dureza Shore A e alteração de cor. Todas as amostras foram submetidas à 2000 ciclos de termociclagem. O Dentusil apresentou os seguintes valores: Shore A (40,50); ΔE (0,83); absorção (0,30); solubilidade (0,01). Já o Trusoft apresentou os seguintes valores: Shore A (18,50); ΔE (3,92); absorção (1,48); solubilidade (1,26). O UfiGel P e SC apresentaram resultados semelhantes e intermediarios para os 3 testes. Portanto conclui-se que todas as propriedades estão intimamente relacionadas e que quanto maior for a dureza inicial do material, menor será a absorção e solubilidade e consequentemente menor será a alteração de cor.

The purpose of this study was to investigate absorption, solubility, hardness and colour change of 4 soft liners after thermocycling. A resin base (Trusoft) and three silicone base (Dentusil, Ufi Gel P e Ufi Gel SC) were used on this research. A total of eighty samples were manufactured: forty for absorption and solubility test and forty for both hardness and colour change tests. All samples were subjected to 2000 hours of thermocycling. Dentusil showed the following values: Shore A hardness (40.50), colour change (ΔE=0.83), absorption (0.30) and solubility (0.01). Trusoft, on the other hand, showed the following values: Shore A hardness (18.50), colour change (ΔE=3.92), absorption (1.48) and solubility (1.26). Both UfiGel P and SC showed similar results for all three tests. All properties are linked and as big is the initial hardness, small will be both absorption and solubility and consequently small will be the colour change.

Alteração da cor das próteses maxilofaciais: revisão de literatura / Color changes in maxillofacial prostheses: literature review

Um dos maiores problemas para o protesista maxilofacial está em como controlar a alteração da cor das próteses no decorrer de seu uso. Para isso, pesquisas têm sido feitas, ao longo dos anos, sobre os diversos materiais e sistemas de pigmentação disponíveis no mercado, além de avaliação sobre como esses materiais se comportam ante as exposições ambientais a que são submetidos. Portanto, o presente trabalho teve a finalidade de avaliar, através da revisão de literatura desde 1969 até os dias de hoje, a alteração da cor dos materiais utilizados em próteses maxilofaciais, pigmentados ou não após o envelhecimento. Para isso, os materiais, pigmentos, método de exposição e de avaliação dos corpos-de-prova foram analisados separadamente. Pôdese observar que o silicone Silastic MDX 44210 propiciou os melhores resultados com relação à estabilidade de cor, sendo ainda considerado como um ótimo material de escolha para uso em próteses maxilofaciais. Já os pigmentos intrínsecos resultaram em menor alteração de cor. O envelhecimento ao ar livre apresentou alteração de cor menor que o envelhecimento acelerado. No entanto, é importante esclarecer que, devido à diversidade de materiais e pigmentos disponíveis em cada país e à ausência de padronização internacional, há necessidade de se pesquisar mais sobre as propriedades dos materiais, bem como a alteração de cor.

A Maxilofacial prosthesist problem is how to control the color change of the prostheses during use. Researches have been made, along the years, about several materials and pigmentation systems available in market, besides evaluation about behavior materials in front of the environmental exhibitions that they are submitted. Therefore, the present work had the purpose of evaluating, through the literature revision since 1969 until today, the color change of the materials used in prostheses maxilofaciais pigmented or not after aging. For that, materials, pigments, exhibition and evaluation of the body proofs methods were analyzed separately. It could be observed that Silastic MDX 44210 silicone obtained the best results in color stability, being considered as a great choice material for use in maxillofacial prostheses. The outdoors aging presented smaller color change than accelerated aging. However, it is important to observe that due to the diversity of materials and available pigments in each country and absence of the international standardization, there is a need to research more about the properties of the materials, as well color change.