Influence of prior 810-nm-diode intracanal laser irradiation on hydrophilic resin-based sealer obturation

Dentin wall structural changes caused by 810-nm-diode laser irradiation can influence the sealing ability of endodontic sealers. The objective of this study was to evaluate the apical leakage of AH Plus and RealSeal resin-based sealers with and without prior diode laser irradiation. Fifty-two single-rooted mandibular premolars were prepared and divided into 4 groups, according to the endodontic sealer used and the use or non-use of laser irradiation. The protocol for laser irradiation was 2.5W, continuous wave in scanning mode, with 4 exposures per tooth. After sample preparation, apical leakage of 50% ammoniacal silver nitrate impregnation was analyzed. When the teeth were not exposed to irradiation, the Real Seal sealer achieved the highest scores, showing the least leakage, with significant differences at the 5% level (Kruskal-Wallis test, p = 0.0004), compared with AH Plus. When the teeth were exposed to the 810-nm-diode laser irradiation, the sealing ability of AH Plus sealer was improved (p = 0282). In the Real Seal groups, the intracanal laser irradiation did not interfere with the leakage index, showing similar results in the GRS and GRSd groups (p = 0.1009).

Effect of different root caries treatments on the sealing ability of conventional glass ionomer cement restorations

In this study we compared the microleakage of conventional glass ionomer cement (GIC) restorations following the use of different methods of root caries removal. In vitro root caries were induced in 75 human root dentin samples that were divided in five groups of 15 each according to the method used for caries removal: in group 1 spherical carbide burs at low speed were used, in group 2 a hand-held excavator was used, and in groups 3 to 5 an Er,Cr:YSGG laser was used at 2.25 W, 40.18 J/cm(2) (group 3), 2.50 W, 44.64 J/cm(2) (group 4) and 2.75 W, 49.11 J/cm(2) (group 5). The air/water cooling during irradiation was set to 55%/65% respectively. All cavities were filled with GIC. Five samples from each group were evaluated by scanning electron microscopy (SEM) and the other ten samples were thermocycled and submitted to a microleakage test. The data obtained were compared by ANOVA followed by Fisher's test (pa parts per thousand currency sign0.05). Group 4 showed the lowest microleakage index (56.65 6.30; p < 0.05). There were no significant differences among the other groups. On SEM images samples of groups 1 and 2 showed a more regular interface than the irradiated samples. Demineralized dentin below the restoration was observed, that was probably affected dentin. Group 4 showed the lowest microleakage values compared to the other experimental groups, so under the conditions of the present study the method that provided the lowest microleakage was the Er,Cr:YSGG laser with a power output of 2.5 W yielding an energy density of 44.64 J/cm(2).

Clinical Performance of Porcelain Laminate Veneers: Outcomes of the Aesthetic Pre-evaluative Temporary (APT) Technique

This article evaluates the long-term clinical performance of porcelain laminate veneers bonded to teeth prepared with the use of an additive mock-up and aesthetic pre-evaluative temporary (APT) technique over a 12-year period. Sixty-six patients were restored with 580 porcelain laminate veneers. The technique, used for diagnosis, esthetic design, tooth preparation, and provisional restoration fabrication, was based on the APT protocol. The influence of several factors on the durability of veneers was analyzed according to pre- and postoperative parameters. With utilization of the APT restoration, over 80% of tooth preparations were confined to the dental enamel. Over 12 years, 42 laminate veneers failed, but when the preparations were limited to the enamel, the failure rate resulting from debonding and microleakage decreased to 0%. Porcelain laminate veneers presented a successful clinical performance in terms of marginal adaptation, discoloration, gingival recession, secondary caries, postoperative sensitivity, and satisfaction with restoration shade at the end of 12 years. The APT technique facilitated diagnosis, communication, and preparation, providing predictability for the restorative treatment. Limiting the preparation depth to the enamel surface significantly increases the performance of porcelain laminate veneers. (Int J Periodontics Restorative Dent 2012;32:625-635.)

The impact of ozone treatment on enamel physical properties

PURPOSE: To assess the effects of the highly reactive molecule of ozone on sound enamel physical properties and its effects on sealing ability. METHODS: The effect of ozone on sealant tag length, microleakage and unfilled area proportion were evaluated on intact and prepared sound molar fissures. Microhardness, contact angle and acid resistance tests were performed on ground sound smooth surfaces. The samples were treated with ozone for 40 seconds (HealOzone). Control samples were treated with air (modified HealOzone) or left untreated. RESULTS: No statistically significant difference was observed between the control and ozone treated samples in all tests. Prepared fissures exhibited no unfilled areas and a statistically significantly lower microleakage compared to intact fissures. Ozone was shown to dehydrate enamel and consequently enhance its microhardness, which was reversible.

Performance of a conventional sealant and a flowable composite on minimally invasive prepared fissures

Three different fissure preparation procedures were tested and compared to the non-invasive approach using a conventional unfilled sealant and a flowable composite. Eighty permanent molars were selected and divided into 4 groups of 20 teeth each. All the teeth were split into 2 halves, and the exposed fissures were photographed under a microscope (35x) before and after being prepared using the following methods: (I) Er:YAG laser (KEY Laser, KaVo) 600 mJ pulse energy, 6 Hz; (II) diamond bur; (III) Er: YAG laser (KEY Laser, KaVo) 200 mJ pulse energy, 4 Hz; (IV) Control group: Powder jet cleaner (Prophyflex, KaVo, Germany). The pre-and postimages were superimposed in order to evaluate the amount of hard tissue removed. Ten teeth in each group were then acid etched and sealed with an unfilled sealant (Delton opaque, Dentsply), while the remaining 10 teeth were acid etched, primed and bonded (Prime ; Bond NT, Dentsply) and sealed with a flowable composite (X-flow, DeTrey, Dentsply). Material penetration and microleakage were evaluated after thermocycling (5000 cycles) and staining with methylene blue 5%. ANOVA and Mann-Whitney tests were applied for statistical analysis. The laser 600 mJ and bur eliminated the greatest amount of hard tissue. The control teeth presented the least microleakage when sealed with Delton or X-flow. A correlation between material penetration and microleakage could not be statistically confirmed. Mechanical preparation prior to fissure sealing did not enhance the final performance of the sealant.

Evaluation of different types of enamel conditioning before application of a fissure sealant

The aim of the study was to compare fissure sealant quality after mechanical conditioning of erbium-doped yttrium aluminium garnet (Er:YAG) laser or air abrasion prior to chemical conditioning of phosphoric acid etching or of a self-etch adhesive. Twenty-five permanent molars were initially divided into three groups: control group (n = 5), phosphoric acid etching; test group 1 (n = 10), air abrasion; and test group 2, (n = 10) Er:YAG laser. After mechanical conditioning, the test group teeth were sectioned buccolingually and the occlusal surface of one half tooth (equal to one sample) was acid etched, while a self-etch adhesive was applied on the other half. The fissure system of each sample was sealed, thermo-cycled and immersed in 5% methylene dye for 24 h. Each sample was sectioned buccolingually, and one slice was analysed microscopically. Using specialized software microleakage, unfilled margin, sealant failure and unfilled area proportions were calculated. A nonparametric ANOVA model was applied to compare the Er:YAG treatment with that of air abrasion and the self-etch adhesive with phosphoric acid (α = 0.05). Test groups were compared to the control group using Wilcoxon rank sum tests (α = 0.05). The control group displayed significantly lower microleakage but higher unfilled area proportions than the Er:YAG laser + self-etch adhesive group and displayed significantly higher unfilled margin and unfilled area proportions than the air-abrasion + self-etch adhesive group. There was no statistically significant difference in the quality of sealants applied in fissures treated with either Er:YAG laser or air abrasion prior to phosphoric acid etching, nor in the quality of sealants applied in fissures treated with either self-etch adhesive or phosphoric acid following Er:YAG or air-abrasion treatment.

Microfiltración en restauraciones coronarias completas libres de metal

En el presente trabajo se estudió la microfiltración de núcleos de alúmina cementados con cemento de resina autoacondicionante y con cemento de ionómero de vidrio convencional. Una vez preparadas las muestras se sumergieron en azul de metileno, para luego ser cortadas longitudinalmente. Los cortes fueron observados en una lupa estereoscópica, estableciéndose su grado de filtración por penetración del colorante. El análisis estadístico demostró que las muestras cementadas con cemento de resina tuvieron menor filtración que las cementadas con ionómero de vidrio.

Conservative endodontic management of teeth associated with extensive periapical pathology: report of two cases

Traditionally, long-term calcium hydroxide dressings have been recommended for the conservative management of large periapical lesions. However, calcium hydroxide therapy has some disadvantages such as variability of treatment time, difficulties with patient follow-up and prolonged treatment periods that increase the risk of root canal contamination via microleakage and crown fractures. This paper reports the healing of large periapical lesions following conservative non-surgical treatment with calcium hydroxide dressings.

Comportamento mecânico e biológico de implante dentário com interface cônica interna

The general aim of this study was to evaluate the conical interface of pilar/implant. The specific aims were to evaluate the influence of hexagonal internal index in the microleakage and mechanical strength of Morse taper implants; the effect of axial loading on the deformation in cervical region of Morse taper implants of different diameters through strain gauge; the effect of axial loading in cervical deformation and sliding of abutment into the implant by tridimensional measurements; the integrity of conical interface before and after dynamic loading by microscopy and microleakage; and the stress distribution in tridimensional finite element models of Morse taper implants assembled with 2 pieces abutment. According to the obtained results, could be concluded that the diameter had influence in the cervical deformation of Morse taper implants; the presence of internal hexagonal index in the end of internal cone of implant didn´t influenced the bacterial microleakage under static loading neither reduced the mechanical strength of implants; one million cycles of vertical and off-center load had no negative influence in Morse taper implant integrity.

Selamento coronário em Endodontia

Introdução: A Endodontia é a especialidade da Medicina Dentária responsável pelo estudo e tratamento da câmara pulpar, de todo o sistema de canais radiculares e dos tecidos periapicais, bem como das doenças que os afetam. O selamento da porção coronária dos dentes alvo de tratamento endodôntico apresenta-se como um critério determinante no sucesso ou insucesso do tratamento. São vários os fatores que podem proporcionar um correto selamento coronário evitando assim a microinfiltração de microorganismos no sistema de canais radiculares. Entre estes fatores destacam-se o tratamento pré-endodôntico, a correta e eficaz instrumentação e desinfeção dos canais radiculares, a aplicação de materiais de selamento imediato, o número de sessões em que é concluído o tratamento e ainda a restauração provisória e definitiva do dente tratado endodonticamente. Objetivos: A elaboração deste trabalho de revisão teve como principais objetivos aprofundar o conhecimento sobre o selamento coronário tendo em conta as consequências deste processo no prognóstico de dentes alvo de tratamento endodôntico, bem como, os meios a utilizar pelo clínico para prevenir a microinfiltração através da porção coronária e os materiais mais indicados para que o selamento seja alcançado. Materiais e Métodos: Foi realizada uma pesquisa bibliográfica de artigos científicos disponíveis nas bases de dados eletrónicas MEDLINE/Pubmed, Science Direct, Scielo e B-on. As palavras-chave utilizadas nesta pesquisa foram: Coronal Seal, Coronal Microleakage, Coronal Leakage, Temporary Restauration, Temporary Filling Materials, Restauration in Endodontics, Post and Core Restauration, Restorative Materials. Esta pesquisa foi realizada entre Março de 2016 e Maio do mesmo ano e dela resultou a seleção de 132 artigos publicados entre 1985 e 2016, primeiramente pela leitura do titulo e do abstract. Após a leitura completa dos artigos excluíram-se 94 por não se terem considerado relevantes para a elaboração desta revisão bibliográfica, obtendo-se um total de 38 artigos utilizados. Foi também realizada uma pesquisa bibliográfica na biblioteca da Universidade Fernando Pessoa, na secção dedicada à Endodontia, da qual resultou a seleção dos manuais que se encontram descritos pormenorizadamente na bibliografia. Conclusão: O Médico Dentista deve estar sensibilizado para as implicações que o selamento coronário tem para o sucesso do tratamento endodôntico, uma vez que este pode afetar o resultado de todo o tratamento.

Cárie secundária e propriedades antibacterianas dos materiais restauradores

Grande parte do tempo clínico do Médico Dentista é, atualmente, gasto a substituir restaurações dentárias realizadas no passado devido a fraturas ou fenómenos de cárie secundária. Pesquisou-se, assim, para a realização desta monografia em diferentes bases de pesquisa acerca dos fenómenos de cárie e cárie secundária. Um dos objetivos desta revisão bibliográfica estudar a microbiologia associada á cárie secundária, a histopatologia da lesão, o diagnóstico e os problemas associados ao diagnóstico. pretende-se, também, nesta monografia devido á sua pertinência investigar o potencial bacteriostático e bactericida dos diversos materiais disponíveis e em que situações esse efeito é potenciado, de modo a auxiliar o clinico na sua decisão no momento de restauração dentária, procurando prevenir ou adiar a necessidade de efetuar uma nova restauração. Para a realização desta monografia foram realizadas pesquisas nos motores de busca PubMed, B-on, Science Direct e Sci-elo. Depois de selecionados os artigos com interesse e com a utilização de seguintes palavras-chave e combinações de palavras sendo que no final foram selecionados 58 Artigos, dentro dos últimos 10 anos na língua portuguesa e na língua inglesa. Apesar da microbiologia e dos fenómenos histopatológicos de desenvolvimento da lesão estarem bem documentados, não existe consenso no que toca ao diagnóstico e tratamento das lesões. Existem diversos métodos de diagnóstico ao alcance da prescrição do Médico Dentista, sendo que, no entanto, nem todos estão indicados para o diagnóstico de lesões de cárie. Face á grande variedade de materiais restauradores e sistemas adesivos existentes no mercado torna-se imperativo que o Médico Dentista tenha os conhecimentos necessários sobre o potencial antibacteriano desses mesmos materiais. Sendo, assim, capaz de concluir mediante a situação apresentada: as vantagens, desvantagens e potencialidades dos diversos materiais á sua disposição na prevenção de lesões de cárie inicial e cárie secundária, aumentando a sobrevivência das peças dentárias. Conclui-se que a cárie secundária não é um fenómeno exclusivo a nenhum tipo de material forrador, ou restaurador não existindo também nenhum material capaz de efetuar com elevadas taxas de sucesso a sua prevenção. Contudo, atualmente, vem-se procurando a utilização de materiais que proporcionem um maior selamento da estrutura dentária, diminuindo a microinfiltração e consequentemente diminuindo os fenómenos de cárie secundária.