Photofrin® was first approved in the 1990s as a sensitizer for use in treating cancer via photodynamic therapy (PDT). Since then a wide variety of dye sensitizers have been developed and a few have been approved for PDT treatment of skin and organ cancers and skin diseases such as acne vulgaris. Porphyrinoid derivatives and precursors have been the most successful in producing requisite singlet oxygen, with Photofrin® still remaining the most efficient sensitizer (quantum yield = 0.89) and having broad food and drug administration (FDA) approval for treatment of multiple cancer types. Other porphyrinoid compounds that have received approval from US FDA and regulatory authorities in other countries include benzoporphyrin derivative monoacid ring A (BPD-MA), meta-tetra(hydroxyphenyl)chlorin (m-THPC), N-aspartyl chlorin e6 (NPe6), and precursors to endogenous protoporphyrin IX (PpIX): 1,5-aminolevulinic acid (ALA), methyl aminolevulinate (MAL), hexaminolevulinate (HAL). Although no non-porphyrin sensitizer has been approved for PDT applications, a small number of anthraquinone, phenothiazine, xanthene, cyanine, and curcuminoid sensitizers are under consideration and some are being evaluated in clinical trials. This review focuses on the nature of PDT, dye sensitizers that have been approved for use in PDT, and compounds that have entered or completed clinical trials as PDT sensitizers.

https://www.mdpi.com/1996-1944/6/3/817/pdf

Dye Sensitizers for Photodynamic Therapy.

Recent advances in BMP receptor signaling

Direct comparison of the bond strength results of the different test methods: A critical literature review

OBJECTIVES
Resin-based dental materials are not inert in the oral environment, and may release components, initially due to incomplete polymerization, and later due to degradation. Since there are concerns regarding potential toxicity, more precise knowledge of the actual quantity of released eluates is necessary. However, due to a great variety in analytical methodology employed in different studies and in the presentation of the results, it is still unclear to which quantities of components a patient may be exposed. The objective of this meta-analytical study was to review the literature on the short- and long-term release of components from resin-based dental materials, and to determine how much (order of magnitude) of those components may leach out in the oral cavity.


METHODS
Out of an initial set of 71 studies, 22 were included. In spite of the large statistical incertitude due to the great variety in methodology and lack of complete information (detection limits were seldom mentioned), a meta-analytical mean for the evaluated eluates was calculated. To relate the amount of potentially released material components with the size of restorations, the mean size of standard composite restorations was estimated using a 3D graphical program.


RESULTS
While the release of monomers was analyzed in many studies, that of additives, such as initiators, inhibitors and stabilizers, was seldom investigated. Significantly more components were found to be released in organic than in water-based media. Resin-based dental materials might account for the total burden of orally ingested bisphenol A, but they may release even higher amounts of monomers, such as HEMA, TEGDMA, BisGMA and UDMA. Compared to these monomers, similar or even higher amounts of additives may elute, even though composites generally only contain very small amounts of additives. A positive correlation was found between the total quantity of released eluates and the volume of extraction solution.


SIGNIFICANCE
There is a clear need for more accurate and standardized analytical research to determine the long-term release from resin-based materials. Several guidelines for standardization are proposed.

How much do resin-based dental materials release? A meta-analytical approach (vol 27 pg 723, 2011)

Statistical Methods in Agriculture and Experimental Biology.

http://download.upf.br/editora/revistas/rfo/14-01/32-36.pdf

Influência de colutórios bucais na dureza de resinas compostas Influence of mouthrinses on the hardness of composite resin materials

Objetivo : o objetivo do presente estudo foi comparar a influencia de diferentes protocolos de polimento sobre a rugosidade superficial de uma resina composta nanoparticulada. Metodologia : foram confeccionados 30 corpos de prova (1,5 mm espessura e 6 mm diâmetro), divididos em 3 grupos (n=10), de acordo com o tipo de polimento realizado: 1. Grupo controle; 2. Borrachas abrasivas em 3 granulacoes (grossa, media, fina); 3 Borracha abrasiva de granulacao unica. Todos os grupos receberam acabamento com lixa d’agua, simulando uma ponta diamantada fina, sendo que o grupo controle nao recebeu o polimento com borracha, apos esse acabamento. Apos o polimento dos grupos 2 e 3, a rugosidade superficial de cada corpo de prova, dos tres grupos, foi avaliada em 3 medidas, atraves de rugosimetro, sendo calculada a media aritmetica dos 3 valores picos e vales. A analise estatistica inferencial foi feita por meio da ANOVA a 1-criterio e teste de Tukey, para comparacoes multiplas, com nivel de significância de 5%. Resultados : observaram-se maiores valores de rugosidade no grupo controle (3,31µm), seguido do polimento de 1 passo (1,53µm) e 3 passos (0,48µm). Conclusao : diante disso, observa-se alta rugosidade superficial no acabamento com pontas diamantadas, simulado pelo grupo controle, e sua reducao apos o polimento. Entretanto, apenas o sistema de 3 passos foi capaz de produzir uma lisura superficial clinicamente aceitavel.

/pdf/comparacao-do-efeito-de-diferentes-protocolos-de-polimento-16p7ik0zrz.pdf

Comparação do efeito de diferentes protocolos de polimento na rugosidade superficial de restaurações de resina composta

Resumo Introducao As resinas compostas estao sujeitas a desafios na cavidade oral relacionados aos habitos dos pacientes, que podem comprometer a integridade e longevidade das restauracoes. As consequencias da associacao do consumo de bebidas e o uso de cigarros a profilaxia profissional precisam ser estudadas. Objetivo O objetivo desse estudo foi avaliar como o jateamento com bicarbonato de sodio afeta a mudanca de massa (sorcao e solubilidade) de uma resina composta exposta a fumaca de cigarro, vinho tinto e cafe. Material e metodo Oitenta corpos-de-prova de resina composta (FiltekZ350 XT - 3M/ESPE) foram preparados e distribuidos em 8 grupos (n=10): G1 (jateamento + agua destilada), G2 (jateamento + cafe), G3 (jateamento + vinho tinto), G4 (jateamento + fumaca de cigarro), G5 (agua destilada), G6 (cafe), G7 (vinho tinto) e G8 (fumaca de cigarro). Os corpos-de-prova de resina composta foram pesados em tres tempos diferentes para obter M1 (massa inicial), M2 (massa apos 30 dias de armazenamento nas solucoes testadas e exposicao ao agente) e M3 (apos dessecacao). Os valores de sorcao e solubilidade foram calculados e analisados usando ANOVA 2-fatores e teste Tukey (5%). Resultado Os grupos experimentais tiveram maior sorcao e solubilidade comparado ao grupo controle, independentemente do uso do jateamento. Nao houve diferenca estatistica na sorcao para o fator jateamento. Porem, a solubilidade foi maior nos grupos jateados. Conclusao: O jateamento com bicarbonato de sodio foi capaz de intensificar a solubilidade da resina testada, embora nao tenha aumentado significativamente os valores de sorcao.

Mass change of a sodium bicarbonate air-polished nanocomposite exposed to cigarette smoke, coffee, and red wine

This study evaluated the effect of retentive areas on onlay preparations on the dimensional alterations in condensation and addition silicone materials. A standard model with an onlay preparation was made. Each impression material was used through the double or simultaneous impression technique (n=25), resulting in a hundred impressions of the same model. Impressions were poured with type IV dental stone. Digital images were taken with a light microscope and the distances between the reference points created on the plaster dies were compared with the ones on the standard model. In the occlusal, mesial-medium and mesial-cervical segments, the double impression (DI) with condensation silicone presented similar values compared to the standard model. The values of the addition silicone with DI were similar to the standard model only in the mesial-occlusal segment. In the other segments (distal-cervical, distal-medium and distal-occlusal), all groups were statistically different from the control. It could be concluded that addition and condensation silicone impressions provided plaster dies with significant dimensional alterations in most of the evaluated areas when compared to the standard model. The retentive areas related to the onlay preparation influenced the dimensional stability of the addition and condensation silicone impressions.

Influence of retentive areas associated to onlay preparations on the dimensional stability of silicone impression materials.

The dentin exposed to erosive challenges is often superficially protected to prevent progression of the lesion. This study investigated the marginal and internal adaptation of composite resin restorations made on surfaces that had first been treated with different methods for controlling erosion. Cavities with margins in dentin were prepared in bovine incisors (n=360) and were divided into three groups according to the method for controlling the erosive challenge: negative control, topical application of fluoride and resin-modified glass ionomer varnish. The specimens were then randomly divided into three sub-groups according to the exposure to simulated gastric acid solution (DES) (5% HCl, pH=2.2) and subsequent remineralization (RE): negative control, 9 and 18 cycles of DES-RE. Finally, teeth were divided into four groups, depending on the bonding agent used for composite resin restoration (n=10): conventional etch-and-rinse adhesive system (2 and 3 steps) and self-etching (1 and 2 steps). Front and internal images of the interface tooth/restoration were recorded in stereoscopic microscope (15x) to quantify the percentage of adhesive failures. Despite the promising results of the resin-modified glass ionomer varnish after 9 cycles; no protective material prevented increased internal defects after 18 erosive cycles. More continuous internal margins were noted with etch-and-rinse acid systems after more intense erosion. The maintenance of internal margins in eroded substrates was positively influenced by the resin-modified glass ionomer varnish and, under the most aggressive challenge, by the use of etch-and-rinse adhesives systems. Keywords: Tooth Erosion. Dentin. Acid Gastric. ResumoA dentina exposta a desafios erosivos e muitas vezes superficialmente protegida para prevenir a progressao da lesao. Este estudo investigou a adaptacao marginal e interna de restauracoes de resina composta realizadas em superficies que foram previamente tratadas com diferentes metodos para controlar a erosao. Cavidades com margens em dentina foram preparadas em dentes incisivos bovinos (n=360) e divididas em tres grupos de acordo com o metodo de controle do desafio erosivo: controle negativo, aplicacao topica de fluor e verniz de ionomero de vidro modificado por resina. Os especimes foram entao divididos aleatoriamente em tres subgrupos de acordo com a exposicao a solucao de acido gastrico simulada (DES) (HCl a 5%, pH = 2,2) e posterior remineralizacao (RE): controle negativo, 9 e 18 ciclos de DES-RE. Por fim, os dentes foram divididos em quatro grupos, de acordo com o agente de uniao utilizado para a restauracao da resina composta (n=10): sistema adesivo convencional (2 e 3 passos) e autocondicionante (1 e 2 passos). Imagens frontais e internas da interface dente/restauracao foram registradas em microscopio estereoscopico (15x) para quantificar a porcentagem de falhas adesivas. Apesar dos resultados promissores do verniz de ionomero de vidro modificado por resina apos 9 ciclos; nenhum material de protecao impediu o aumento de defeitos internos apos 18 ciclos erosivos. Margens internas mais continuas foram observadas com sistemas adesivos convencionais apos erosao mais intensa. A manutencao das margens internas em substratos erodidos foi influenciada positivamente pelo verniz de ionomero de vidro modificado por resina e, sob o desafio mais agressivo, pelo uso de sistemas de adesivos convencionais. Palavras-chave: Erosao Dentaria. Dentina. Acido Gastrico.

/pdf/effect-of-dental-erosion-and-methods-for-its-control-on-the-1ldawgtif8.pdf

Andrea Nóbrega Cavalcanti

Papers

Influência de colutórios bucais na dureza de resinas compostas Influence of mouthrinses on the hardness of composite resin materials

Comparação do efeito de diferentes protocolos de polimento na rugosidade superficial de restaurações de resina composta

Mass change of a sodium bicarbonate air-polished nanocomposite exposed to cigarette smoke, coffee, and red wine

Influence of retentive areas associated to onlay preparations on the dimensional stability of silicone impression materials.

Effect of Dental Erosion and Methods for its Control on the Marginal and Internal Adaptation of Restorations with Different Adhesive Systems