Direct Esthetic Restorations Based on Translucency and Opacity of Composite Resins

Light dynamics is a relevant phenomenon with respect to esthetic restorations, as incorrect analysis of the optical behavior of natural dentition may lead to potential clinical failures. The nature of incident light plays a major role in determining the amount of light transmission or reflection, and how an object is perceived depends on the nature of the light source. Natural teeth demonstrate translucency, opalescence, and fluorescence, all of which must be replicated by restorative materials in order to achieve clinical success. Translucency is the intermediary between complete opacity and complete transparency, making its analysis highly subjective. In nature, the translucency of dental enamel varies from tooth to tooth, and from individual to individual. Therefore, four important factors must be considered when appraising translucency. Presence or absence of color, thickness of the enamel, degree of translucency, and surface texture are essential components when determining translucency. State-of-the-art resin composites provide varying shades and opacities that deliver a more faithful reproduction of the chromaticity and translucency/opacity of enamel and dentin. This enables the attainment of individualized and customized composite restorations. The objective of this article is to provide a review of the phenomena of translucency and opacity in the natural dentition and composite resins, under the scope of optics, and to describe how to implement these concepts in the clinical setting.CLINICAL SIGNIFICANCEChoosing composite resins, based on optical properties alone, in order to mimic the properties of natural tooth structures, does not necessarily provide a satisfactory esthetic outcome. In many instances, failure ensues from incorrect analysis of the optical behaviors of the natural dentition as well as the improper use of restorative materials. Therefore, it is necessary to implement a technique that enables a restorative material to be utilized to its full potential to correctly replicate the natural teeth.(J Esthet Restor Dent 23:73-88, 2011).

Clinical Efficiency of Low-Level Diode Laser in Reducing Dentin Hypersensitivity

Dentin hipersensitivity (DH) is a relatively common clinical condition, especially in periodontal patients after treatment. In this study it was evaluated 28 teeth who presented dentin hypersensitivity. The teeth were subjected to clinical and radiographic exams and were divided into groups following the treatment and the time of examination after application proposed: GI: PO 3% (Potassium Oxalate-group control)/Baseline; GII: PO 3%/3 days after first session; GIII: PO 3%/6 days; GIV: PO 3%/30 days; GV: PO 3%/60 days; GVI: PO 3%/90 days; GVII: Laser (Low-level diode laser with 110 mW/cm(2))/Baseline; GVIII: Laser/7 days after first session; GIX: Laser/14 days; GX: Laser/30 days; GXI: Laser/60 days; and GXII: Laser/90 days. The groups I-VI, the teeth were subjected to 3 applications (GI-GIII) of desensitizing agent at regular intervals of seven days. The Groups VII-XI, each tooth was subjected to three applications (GVII GIX) in three different points (mesial, meddle and distal surfaces) with an interval of 72 h. The time of application in each point was of 33 s and the patients from both groups were followed up to 90 days. The nonparametric test Friedman (alpha = 0.05) was applied and the test of Mann Whitney (alpha = 0.05) was used to compare the time of examination between groups. The application of Laser was effective 6 days after first session and to PO was 30 days. It was observed that both treatments were effective for the reduction of dentin hypersensitivity, however the laser presented better effectiveness.

Atypical dento-alveolar fracture fixed with screws: a technical note

Dento-alveolar process fracture is an important and common event in the dental office practice usually managed under the well-established protocols, but sometimes this kind of lesion is evaluated in the hospital emergency rooms without attention to the dental injuries. In this type of trauma, the time between the injury and the definitive resolution is essential for the treatment success, usually 1 h in cases of dento-alveolar fractures (tooth and alveolar bone). This paper describes the management of a patient with unusual dento-alveolar fracture caused by gunshot and treated using screw fixation.

Ability of Gutta-Percha and Resilon to Fill Simulated Lateral Canals by Using the Obtura II System

Introduction: The aim of this study was to evaluate the ability of Resilon (Resilon Research, LLC, North Branford, CT) and 2 types of gutta-percha to fill simulated lateral canals when using the Obtura II system (Model 823-700; Obtura Spartan, Fenton, MO). Methods: Forty-five human single-rooted teeth were selected and subjected to root canal preparation. After that, simulated lateral canals were made at 2, 5, and 8 mm from the working length (WL). The specimens were divided into 3 groups (n = 15) according to the filling material used: Obtura Flow 150 gutta-percha (Obtura flow), Odous Endo Flow gutta-percha (Odous; Odous de Deus Ind e Corn. Ltda Belo Horizonte, MG, Brazil), and Resilon pellets (Resilon). Root canals were filled using the Obtura II system with the tip inserted to 3 mm from the WL. No sealer was used for root canal obturation. Specimens were subjected to a tooth decalcification and clearing method, and filling of the lateral canals was analyzed by digital radiography and photographs. The measurement of lateral canal filling was done using Image Tool software (UTHSCSA Image Tool for Windows version 3.0, San Antonio, TX). Data were statistically analyzed with the Kruskal-Wallis test at 5% significance. Results: All materials showed an ability to penetrate into the simulated lateral canals, with a minimum percentage of 73% in all thirds of the root canal. Conclusions: It was concluded that gutta-percha and Resilon are solid core materials with a lateral canal filling ability when used with the Obtura II system. (J Endod 2012;38:676-679)

Bond strength of an adhesive system irradiated with Nd : YAG laser in dentin treated with Er : YAG laser

The purpose of this in vitro study was to verify through micro tensile bond test the bond strength of an adhesive system irradiated with Nd:YAG laser in dentine previously treated with Er:YAG laser. Twenty caries free extracted human third molars were used. The teeth were divided in four experimental groups (n = 5): (G1) control group; (G2) irradiation of the adhesive system with the Nd:YAG laser; (G3) dentin treatment with Er:YAG laser; (G4) dentin treatment with Er:YAG laser followed by the irradiation of the adhesive system with Nd:YAG laser. The Er:YAG laser fluency parameter for the dentin treatment was of 60 J/cm(2). ne adhesive system was irradiated with the Nd:YAG laser with fluency of 100 J/cm(2). Dental restorations were performed with Adper Single Bond 2/Z250. One tooth from each group was prepared for the evaluation of the adhesive interface under SEM and bond failure tests were also performed and evaluated. The statistical analysis showed statistical significant difference between the groups G1 and G3, G1 and G4, G2 and G3, and G2 and G4; and similarity between the groups G1 and G2, and G3 and G4. The adhesive failures were predominant in all the experimental groups. The SEM analysis showed an adhesive interface with features confirming the results of the mechanical tests. The Nd:YAG laser on the adhesive system did not influence the bond strength in dentin treated or not with the Er:YAG laser.

In Vitro Study of Fracture Load and Fracture Pattern of Ceramic Crowns: A Finite Element and Fractography Analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Root canal treatment of three-rooted maxillary second premolars: Report of four cases

The aim of this report is to contribute to a better understanding of the radiographic, clinical and anatomic findings in maxillary second premolars. This paper reports the endodontic treatment of two cases of three-rooted three-canal maxillary second premolars in different patients, and two sound maxillary second premolars also with three canals and three independent roots in a sibling of one of the patients. Although the presence of maxillary second premolars with one or two canals and one root is much more common, other anatomic conditions can be found. A correct clinical and radiographic diagnosis based on knowledge of root canal anatomy and critical interpretation of radiographs is necessary for a safer and successful endodontic treatment of these teeth.

A Thermal Investigation of Dental Bleaching In Vitro

Objective: Our goal was to investigate the surface temperature variations in the cervical region via infrared thermography, as well as the temperature within the pulp chamber via thermocouples, of mandibular incisors when subjected to dental bleaching using two different 35% hydrogen peroxide gels, red (HP) and green (HPM), when activated by halogen light (HL) and LED light.Background Data: Temperatures increases of more than 5.5 degrees C are considered to be potentially threatening to pulp vitality, while those higher than 10 degrees C can result in periodontal injury.Materials and Methods: Tooth samples were randomly divided into four groups (n = 10 each), according to the bleaching agent and catalyst light source used.Results: Mean values and standard deviations of the temperature increases inside the pulp chamber in the HL groups were 4.4 degrees +/- 2.1 degrees C with HP, and 4.5 degrees +/- 1.2 degrees C with HPM; whereas in the groups using LED light, they were 1.4 degrees +/- 0.3 degrees C for HP, and 1.5 degrees +/- 0.2 degrees C for HPM. For the root surfaces, the maximum temperature increases in the groups irradiated with HL were 6.5 degrees +/- 1.5 degrees C for HP, and 7.5 degrees +/- 1.1 degrees C with HPM; whereas in the groups irradiated with LED light, they were 2.8 degrees +/- 0.7 degrees C with HP, and 3 degrees +/- 0.8 degrees C with HPM. There were no statistically significant differences in pulp and surface temperature increases between the groups using different gels, although the mean temperature increases were significantly higher for the groups irradiated with HL when compared with those irradiated with the LED light (p < 0.05 with Tukey's test).Conclusion: LED light may be safe for periodontal and pulp tissue when using this method, but HL should be used with care.

Reprodutibilidade de uma escala odontológica proposta como indicador de saúde bucal em crianças e adolescentes HIV+/SIDA

O objetivo deste trabalho foi estimar a reprodutibilidade de uma escala odontológica para avaliação da saúde bucal de crianças e adolescentes HIV+. A amostra, com delineamento não probabilístico, constituiu-se de 27 crianças e adolescentes HIV+. A escala foi aplicada, em duas ocasiões, com intervalo de sete dias. Estimou-se a reprodutibilidade intraexaminador pela estatística Kappa. Nas questões relativas à mãe, houve concordância máxima nos itens referentes à importância da saúde bucal, hábito de escovação diária e utilização de escova dental. A procura de atendimento odontológico motivado por estética e para manutenção de hálito puro apresentou concordância boa. Nas questões relativas à criança, observou-se concordância regular nos itens referentes ao fio dental. Com relação à organização do sistema de saúde, chama atenção a dificuldade dos respondentes em relatar o local e o profissional que realizou orientações educativas preventivas. A reprodutibilidade dos domínios percepção, cuidado e promoção foi de 0,48, 0,21 e 0,64, respectivamente. Sugere-se a necessidade de reestruturação das questões componentes dos algoritmos propostos pela escala para as dimensões de percepção e cuidado, a par da necessidade da saúde bucal ser inserida em programas de atendimento a portadores HIV+.

Mutations in IRF6 cause Van der Woude and popliteal pterygium syndromes

Interferon regulatory factor 6 (IRF6) belongs to a family of nine transcription factors that share a highly conserved helix-turn-helix DNA-binding domain and a less conserved protein-binding domain. Most IRFs regulate the expression of interferon-alpha and -beta after viral infection(1), but the function of IRF6 is unknown. The gene encoding IRF6 is located in the critical region for the Van der Woude syndrome (VWS; OMIM 119300) locus at chromosome 1q32-q41 (refs 2,3). The disorder is an autosomal dominant form of cleft lip and palate with lip pits(4), and is the most common syndromic form of cleft lip or palate. Popliteal pterygium syndrome (PPS; OMIM 119500) is a disorder with a similar orofacial phenotype that also includes skin and genital anomalies(5). Phenotypic overlap(6) and linkage data(7) suggest that these two disorders are allelic. We found a nonsense mutation in IRF6 in the affected twin of a pair of monozygotic twins who were discordant for VWS. Subsequently, we identified mutations in IRF6 in 45 additional unrelated families affected with VWS and distinct mutations in 13 families affected with PPS. Expression analyses showed high levels of Irf6 mRNA along the medial edge of the fusing palate, tooth buds, hair follicles, genitalia and skin. Our observations demonstrate that haploinsufficiency of IRF6 disrupts orofacial development and are consistent with dominant-negative mutations disturbing development of the skin and genitalia.

Horizontal transfers of Mariner transposons between mammals and insects

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

TAXONOMIC POSITION of GUIRATINGIA MENDESI (MEGADESMIDAE) and THE EVOLUTION of PERMIAN ENDEMIC BIVALVE FAUNA of THE PARANA BASIN, BRAZIL

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Description of the Larvae of Tapinoma melanocephalum (Hymenoptera: Formicidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Habits hidden underground: a review on the reproduction of the Amphisbaenia with notes on four neotropical species

We review the information currently available on the reproduction of the Amphisbaenia and provide original data on the reproductive biology of four Neotropical species: Amphisbaena alba; A. mertensi; Cercolophia roberti, and Leposternon infraorbitale. In total, we compiled data for 22 species: 17 Amphisbaenidae, 1 Rhineuridae, 3 Bipedidae, and 1 Trogonophidae. The majority of the species were oviparous with the exceptions of Loveridgea ionidesii, Monopeltis anchietae, M. capensis, and Trogonophis wiegmanni. Viviparity was interpreted as a derived trait that evolved independently for at least 3 times within the Amphisbaenia. In most species, reproduction is synchronized with the hot and rainy season and seems to vary with latitude. Although Amphisbaenia eggs have been found in ant nests, it remains disputable whether this is an obligatory or even a preferable location for egg-laying. Incubation time in A. mertensii lasts 59 days and this is the first report encompassing egg-laying to hatching for any Amphisbaenia species. Nonetheless, a two months incubation period seems to be the common rule for oviparous Amphisbaenia. The general pattern of reproductive output in Amphisbaenia is characterized by a low number of eggs/embryos per clutch whose individual size is comparatively large in relation to adult body size. Eggs are markedly elongated on the long axis and arranged in-line within the abdominal cavity possibly to prevent/diminish biomechanic drawbacks of egg bearing. Hatchlings of A. mertensi possess an egg-tooth implanted at the upper jaw, exhibit positive geotropism, and display defensive behaviors known to be present in adults. Our review shows that our current knowledge of Amphisbaenia reproduction is fragmentary, often based on the examination of small samples, and heavily dependent on the publication of anedoctal observations. Future publications on this subject are encouraged.

Aspects of the reproductive biology of the shortfin mako, Isurus oxyrinchus (Elasmobranchii Lamnidae), in the Southeastern region of Brazil

Quatro úteros provenientes de quatro fêmeas prenhas e dois indivíduos recém-nascidos de anequim, Isurus oxyrinchus, foram coletados na região Sudeste do Brasil durante os meses de setembro a novembro de 1993 e 1994. Todos os embriões estavam bem desenvolvidos, próximos ao estágio de nascimento, apresentando a dentição e órgãos internos bastante desenvolvidos. O comprimento total desses embriões variou entre 64,5 e 72,0 cm, e o maior número de embriões observado no interior de uma única fêmea foi 20. As observações aqui realizadas confirmam a oofagia como forma de nutrição dos embriões dessa espécie e sua periodicidade. A presença de dentes no estômago dos embriões sugere que a substituição dos dentes se inicia na fase uterina.