Abstract Objectives This study aimed to assess the effect of proanthocyanidin, palm oil and vitamin E against erosive and erosive+abrasive challenges in vitro after enamel pellicle formation in situ. Methodology Bovine enamel blocks (n=84) were obtained and divided into the following treatment groups: negative control (NC) - deionized water; positive control (PC) - SnCl2/NaF/AmF-containing solution; palm oil (PO); 2% proanthocyanidin (P2); vitamin E (VitE); 2% proanthocyanidin+palm oil (P2PO); and 2% proanthocyanidin+vitamin E (P2VitE). For 5 days, one half of the sample from each group was subjected to erosion and the other half was subjected to erosion+abrasion. The acquired enamel pellicle (AEP) was pre-formed in situ for 30 minutes. The specimens were then treated in vitro with solutions (500 µl, 30s for each group). Subsequently, the blocks were left in the oral cavity for another hour to obtain the modified AEP. The blocks were immersed in 0.5% citric acid (pH=2.5) for 90s, 4×/day. AEP formation and treatment were carried out before the first and third erosive challenges, and after these challenges, abrasive cycles (15s) were performed on half of the samples. Enamel wear was quantified by profilometry and data were analyzed by two-way ANOVA and Tukey’s test (p<0.05). Results All groups showed higher wear when exposed to erosion+abrasion than when exposed to erosion alone (p=0.0001). PO, P2VitE, P2, and P2PO showed enamel wear similar to the PC group, but only PC, PO and P2VitE differed from the NC group. The other groups behaved similarly to NC. Conclusion It was concluded that the combination of proanthocyanidin and vitamin E was effective in reducing wear in the face of in vitro erosive and erosive+abrasive challenges. erosiveabrasive n=84 n84 n 84 (n=84 (NC water (PC SnCl2/NaF/AmFcontaining SnCl2NaFAmFcontaining SnClNaFAmFcontaining SnCl2/NaF/AmF containing SnCl2 NaF AmF SnCl solution (PO) 2 P2 P (P2) VitE (VitE) proanthocyanidinpalm PPO (P2PO) proanthocyanidinvitamin P2VitE. PVitE . (P2VitE) days erosionabrasion abrasion (AEP preformed pre formed 3 minutes 500 (50 µl s group) Subsequently 05 0 0.5 pH=2.5 pH25 pH (pH=2.5 90s 4day day 4 4×/day 15s (15s samples twoway two way Tukeys Tukey p<0.05. p005 p p<0.05 (p<0.05) p=0.0001. p00001 p=0.0001 0001 (p=0.0001) n=8 n8 8 (n=8 AmFcontaining NaFAmFcontaining SnCl2NaFAmF SnClNaFAmF (PO (P2 (VitE (P2PO (P2VitE 50 (5 0. pH=2. pH2 (pH=2. p00 p<0.0 (p<0.05 p0000 p=0.000 000 (p=0.0001 n= (n= NaFAmF (P ( pH=2 (pH=2 p0 p<0. (p<0.0 p000 p=0.00 00 (p=0.000 (n pH= (pH= p<0 (p<0. p=0.0 (p=0.00 (pH p< (p<0 p=0. (p=0.0 (p< p=0 (p=0. (p p= (p=0 (p=

Abstract Proanthocyanidin has been shown to be efficient in inhibiting matrix metalloproteinases. Objective The aim of this in situ study was to evaluate the protective effect of Proanthocyanidin-based mouthrinses either with naturally acidic or with a neutral pH applied on dentin subjected to erosion. Methodology Eight volunteers wore one palatal device in two phases (7 days washout) with 16 samples per group (n=8). The groups under study were: First Phase/ G1 – 10% proanthocyanidin mouthrinse (pH 7.0, Experimental group 1 – Purified Grape Seeds Oligomeric Proanthocyanidins), G2 – 10% proanthocyanidin mouthrinse (pH 3.0, Experimental group 2 – Purified Grape Seeds Oligomeric Proanthocyanidins). Second Phase/ G3 – 0.12% chlorhexidine mouthrinse (pH 7.0, Positive control group), G4 – no previous treatment (Negative control group). Each device was subjected to 3 erosive cycles (5 minutes) per day for 5 days. Treatments with different mouthrinses were applied once after the second erosive challenge (5 minutes). Profilometry was used to quantify dentin loss (µm). Results Data were analyzed by repeated measures of ANOVA followed by Fisher’s test (p<0.05). G1 (1.17±0.69) and G3 (1.22±0.25) showed significantly lower wear values with no statistical difference between them. G2 (2.99±1.15) and G4 (2.29±1.13) presented higher wear values with no significant differences between them. Conclusion The 10% proanthocyanidin mouthrinse (pH 7.0) could be a good strategy to reduce dentin wear progression.

Resumo A literatura acadêmica apresenta conceitos que são explorados pelo seu aspecto formal e informal. Também enfatiza que os relacionamentos interpessoais informais complementam e contribuem de forma sinérgica com os relacionamentos formais que ocorrem nas diversas atividades humanas. Alguns autores estudaram a similaridade entre as partes formal e informal, outros indicaram que se poderia estudar os efeitos conjuntos da interação ou o delineamento dos limites da parte informal pela parte formal ou se ambas apresentariam influências recíprocas. Neste trabalho são comparadas as redes sociais formais e informais de duas turmas distintas de alunos universitários e em momentos diferentes para verificar a existência da interação entre os elementos formais e informais dessas redes. Foi realizado um estudo de campo de caráter exploratório com auxílio da análise de redes sociais por meio do software Ucinet 6.0 e Netdraw. Foram coletadas várias medidas com base na percepção dos alunos e a análise dos dados indicou resultados não condizentes com a literatura, indicando a não ocorrência de relação entre os aspectos formal e informal. Dada a importância dessa interação, cabe aos professores e à instituição de ensino prover meios para que isso ocorra. Os resultados indicam a necessidade de mais estudos científicos a respeito do tema. JEL Code: L14, L84, O17.

Abstract The academic literature presents concepts that are explored by their formal and informal aspects. In addition, it is emphasized that informal interpersonal relationships complement and contribute synergistically with the formal relationships that occur in the various human activities. Some authors have studied the similarity between the formal and informal parts, others have indicated that one could study the joint effects of interaction or the delineation of the boundaries of the informal part by the formal part or if both would have reciprocal influences. In this work we compare the formal and informal social networks of two distinct groups of university students and at different moments to verify the existence of the interaction between the formal and informal elements of these networks. An exploratory field study was carried out with the help of social networks analysis through the software Ucinet 6.0 and Netdraw. Several measures were collected based on the students' perception and the analysis of the data indicated results that were not consistent with the literature, indicating the non-occurrence of a relationship between the formal and informal aspects. Given the importance of this interaction, it is up to the teachers and the educational institution to provide the means for this to occur. The results indicate the need for more scientific studies on the subject.

Abstract Objective The prevalence of dental erosion has been recently increasing, requiring new preventive and therapeutic approaches. Vegetable oils have been studied in preventive dentistry because they come from a natural, edible, low-cost, and worldwide accessible source. This study aimed to evaluate the protective effect of different vegetable oils, applied in two concentrations, on initial enamel erosion. Material and Methods Initially, the acquired pellicle was formed in situ for 2 hours. Subsequently, the enamel blocks were treated in vitro according to the study group (n=12/per group): GP5 and GP100 – 5% and pure palm oil, respectively; GC5 and GC100 – 5% and pure coconut oil; GSa5 and GSa100 – 5% and pure safflower oil; GSu5 and GSu100 – 5% and pure sunflower oil; GO5 and GO100 – 5% and pure olive oil; CON− – Deionized Water (negative control) and CON+ – Commercial Mouthwash (Elmex® Erosion Protection Dental Rinse, GABA/positive control). Then, the enamel blocks were immersed in artificial saliva for 2 minutes and subjected to short-term acid exposure in 0.5% citric acid, pH 2.4, for 30 seconds, to promote enamel surface softening. The response variable was the percentage of surface hardness loss [((SHi - SHf) / SHf )×100]. Data were analyzed by one-way ANOVA and Tukey’s test (p<0.05). Results Enamel blocks of GP100 presented similar hardness loss to GSu100 (p>0.05) and less than the other groups (p<0.05). There was no difference between GP5, GC5, GC100, GSa5, GSu100, GSa100, GSu5, GO5, GO100, CON− and CON+. Conclusion Palm oil seems to be a promising alternative for preventing enamel erosion. However, further studies are necessary to evaluate a long-term erosive cycling.

OBJETIVO: Confrontar com a literatura os dados relacionados à idade, sexo e indicação dos transplantes penetrantes de córnea efetuados no Hospital São Geraldo da Universidade Federal de Minas Gerais (UFMG), de janeiro de 1999 a dezembro de 2005. MÉTODOS: Realizou-se estudo retrospectivo de 887 ceratopatias penetrantes, com dados obtidos dos arquivos da Central Estadual de Notificação de Minas Gerais, MG Transplantes, e dos prontuários dos pacientes do Departamento de Córnea do Hospital São Geraldo. Os dados analisados foram: idade, sexo e diagnóstico pré-operatório das alterações corneanas. As indicações de transplante do período de janeiro de 1999 a junho de 2002 foram comparadas as de julho de 2002 a dezembro de 2005. RESULTADOS: A média da idade dos pacientes foi de 48,3 anos, variando de 4 meses a 97 anos. As principais indicações de transplante penetrante de córnea foram: lesão ulcerativa (34,95%), ceratocone (16,35%), ceratopatia bolhosa do psedofácico (16,01%), leucoma (14,09%), falência primária (7,89%), rejeição (5,64%), distrofia endotelial de Fuchs (1,92%), outras distrofias (1,47%), causa indeterminada (1,23%) e outras causas (0,45%). CONCLUSÃO: A principal indicação de transplante foi para úlcera de córnea em vias de perfuração ou perfurada, responsável por 310 ceratopatias penetrantes. As indicações eletivas mais frequentes de transplantes foram para ceratocone, ceratopatia bolhosa do psedofácico e leucoma, com o crescimento das indicações para ceratopatia bolhosa do psedofácico no período. Mesmo com um aumento significativo no número de transplantes realizados, estratégias que busquem reduzir a alta incidência de ceratopatias penetrantes emergenciais decorrentes de úlceras corneanas devem ser implantadas.

PURPOSE: To determine and compare with the literature data related on age, sex and the main indications for penetrating keratoplasty at the São Geraldo Hospital of Federal Universidade of Minas Gerais (UFMG), from january 1999 until december 2005. METHODS: A retrospective analysis was performed using data from 887 patients submitted to corneal transplantation from january 1999 until december 2005. These data were obtained from the archives of the Central Notification of State of Minas Gerais, MG-Transplantes database, and from the medical records of the São Geraldo Hospital Corneal Department. The data collected were: age, gender and preoperative diagnosis of corneal diseases. A comparative analysis of the most common indications from january 1999 until june 2002 and from july 2002 until december 2005 was also performed. RESULTS: The mean age of patients was 48.3 years, ranging from 4 months to 97 years. The most common corneal graft indications were ulcerative conditions (34.95%), keratoconus (16.35%), bullous keratopathy (16.01%), leukoma (14.09%), primary graft failure (7.89%), graft rejection (5.64%), Fuchs dystrophy (1.92%), other dystrophies (1.47%), undetermined causes (1.23) and other causes (0.45%). CONCLUSION: The main indication for penetrating keratoplasty was corneal ulcer which was almost perfured or perfured, responding for 310 transplants (34.95%). There was a substantial increase in the frequency of pseudophakic bullous keratopathy on the studied period. Even though, a significant increase in the number of corneal transplants, new strategies must be implanted to decrease the number of PK for ulcerative conditions.