ABSTRACT
A descoloração ou perda de translucidez dos materiais cerâmicos usados em odontologia ainda hoje é um problema, especialmente pelo comprometimento estético. Com o objetivo de comparar a estabilidade de cor, blocos de dissilicato de lítio (IPS e.max CAD HT) e de silicato de lítio reforçado com zircônia (Vita Suprinity HT) fresados no desenho de um disco com dimensões de 1,5 × 7 × 12 mm3 (n = 120) foram preparados usando 3 procedimentos de acabamento de superfície: glaze, polimento mecânico e coloração externa e glaze. Em seguida, cada grupo foi dividido em 2 subgrupos de armazenamento, chá preto e café (n = 10/grupo). As mensurações de cor foram medidas com espectrofotômetro (VITA Easyshade) no estágio inicial e após 1 semana, 2 semanas, 1 mês, 2 meses de armazenamento. As alterações de cor (ΔE) foram calculadas e analisadas estatisticamente usando ANOVA (α < 0,05). Observamos que, para ambos os materiais cerâmicos, o procedimento de glaze apresentou valores de mudança de cor estatisticamente menores do que os outros grupos (p < 0,05) após o armazenamento em ambas as bebidas. Os grupos de dissilicato de lítio apresentaram valores de alteração de cor estatisticamente menores em relação aos grupos de silicato de lítio reforçados com zircônia. Conclui-se que, o glaze sozinho levou a uma maior estabilidade de cor em relação ao polimento mecânico e coloração externa o dissilicato de lítio apresentou maior estabilidade de cor em comparação com o silicato de lítio reforçada com zircônia.
The discoloration or loss of translucency of ceramic materials used in dentistry is still a problem today, especially due to aesthetic compromise. In order to compare color stability, lithium disilicate (IPS e.max CAD HT) and zirconia-reinforced lithium silicate (Vita Suprinity HT) blocks were milled into a disc design with dimensions of 1.5 × 7 × 12 mm3 (n = 120). The specimens were prepared using 3 surface finishing procedures: glaze, mechanical polishing and external staining and glaze. Then, each group was divided into 2 storage subgroups, black tea and coffee (n = 10/group). Color measurements were measured with a spectrophotometer (VITA Easyshade) at the initial stage and after 1 week, 2 weeks, 1 month, 2 months of storage. Color changes (ΔE) were calculated and statistically analyzed using ANOVA (α < 0.05). We observed that, for both ceramic materials, the glaze procedure presented statistically lower color change values ââthan the other groups (p < 0.05) after storage in both beverages. The lithium disilicate groups showed statistically lower color change values ââthan the zirconia-reinforced lithium silicate groups. It is concluded that, glaze alone led to greater color stability compared to mechanical polishing and external staining, lithium disilicate showed greater color stability compared to zirconia-reinforced lithium silicate.
Subject(s)
Beverages , Ceramics , Computer-Aided Design , Color , Dental Polishing/methods , Lithium , SilicatesABSTRACT
Objetivo: Este trabalho avaliou a presença de inflamação gengival em áreas adjacentes a restaurações cervicais de classe V e sua relação com a lisura de superfície e adaptação à parede gengival das restaurações. Metodologia: Foram selecionados dezessete pacientes com ausência de fatores modificadores que alterassem o quadro da doença periodontal, excluindo os pacientes que estivessem em tratamento periodontal ou que concluíram em um prazo inferior a três meses. Os pacientes foram examinados por dois examinadores cegos. O examinador 1 avaliou a margem gengival vestibular em dente com restauração cervical de classe V e dentes adjacentes mesial e distal através de sondagem manual. O examinador 2 avaliou a restauração quanto à lisura e acabamento superficial, e à presença ou ausência de excesso de material. Resultados: Os resultados não foram estatisticamente significantes (testes Qui-quadrado e Teste de Fisher, P>0,05). Conclusão: Não houve relação significativa entre a presença de excesso de material restaurador e inflamação gengival, ou entre inflamação e qualidade de lisura da restauração.
Purpose: This study evaluated the presence of gingival inflammation related to class V restorations and its association with surface finishing and restoration adaptation. Methods: The sample was composed by 17 dental patients with no modifiers of periodontal disease. Exclusion criteria comprised subjects under current periodontal treatment or those who completed periodontal treatment less than three months before. All subjects were examined by two examiners in a blind design. Examiner 1 inspected the buccal gingival margin of teeth with class V restorations and the mesial and distal adjacent teeth by means of manual probing. Examiner 2 evaluated the restoration in relation to surface finishing and roughness, and presence/absence of filling overextension. Results: The results were not statistically significant (Chi-square test and Fisher test, P>0.05). Conclusions: No significant association was found between presence of filling overextension and gingival inflammation, or between inflammation and quality of restoration surface.
Subject(s)
Humans , Male , Female , Adult , Gingivitis , Dental Polishing , Dental Restoration, Permanent/adverse effectsABSTRACT
During endodontic therapy, cleaning of root canals is performed using endodontic files and auxiliary chemical substances, and it is important that the endodontist be familiar with the instruments used in daily practice. This study evaluated, under scanning electron microscopy (SEM), the quality of the surface finishing of unused rotary endodontic instruments. Fifty sizes 20, 25 and 30 rotary files from different commercial brands (ProFile, Protaper, Race, Hero and K3 Endo) were removed directly from their packages and had their final 3 mm examined with a scanning electron microscope at x190 magnification with no previous preparation. The images were evaluated by 3 skillful, calibrated, blinded observers according to the following criteria: cutting edge, debris, grooves, microcavities, tip shape, tip position, scraping and transition angle. Data were recorded in worksheets designed for the study. Irregular edges were observed in 50-100 percent of the files. Except for ProFile, all commercial brands presented surface debris in 100 percent of samples. Only Race files showed no grooves or microcavities. K3 Endo files presented the best tip centralization. Excetp for ProTaper files, all commercial brands presented blunt-cutting edges in 100 percent of samples. All types of files presented surface scraping. K3 Endo files and Protaper had a high percentage of transition angle. Based on the evaluation criteria used in the present study, most samples presented a minimum of 2 alterations and a maximum of 7 alterations per instrument. Under the tested conditions, the quality of the surface finishing of the examined instruments was not as expected, given that no instrument was free of imperfections and most of them presented at least 2 and up to 7 types of surface defects. These results suggest that the manufacturing process and the packaging conditions of rotary endodontic instruments are far from ideal.
Durante a terapia endodôntica, a ação de limpeza é realizada com os instrumentos endodônticos auxiliada por substâncias químicas. Sendo assim, é importante que o endodontista conheça como são os instrumentos. Este trabalho visou avaliar a qualidade do acabamento de superfície de instrumentos endodônticos rotatórios por meio de microscopia eletrônica de varredura. Foram selecionados, 50 instrumentos endodônticos rotatórios nos números de 20, 25 e 30, das marcas Profile, Protaper, Race, Hero e K3 Endo, da forma como são encontradas no mercado e sem nenhum preparo prévio. Os instrumentos tiveram seus 3 milímetros finais fotomicrografados em microscópio eletrônico de varredura com ampliação de x190. As imagens foram avaliadas por três profissionais especialistas, e os resultados anotados em planilhas. A metodologia aplicada permitiu concluir que todos os instrumentos das marcas comerciais avaliadas apresentaram inadequações no acabamento da superfície. Cabe aclarar que, observando os critérios selecionados utilizados para avaliação a maioria das amostras apresentaram o mínimo de duas alterações e o máximo de sete por instrumento avaliado.
Subject(s)
Humans , Root Canal Preparation/instrumentation , Equipment Design , Materials Testing , Microscopy, Electron, Scanning , Rotation , Root Canal Preparation/standards , Surface Properties , Technology, DentalABSTRACT
STATEMENT OF PROBLEMS: Conventional feldspathic porcelain is used extensively as a restorative material and it is subjected to grinding and polishing during fabrication and delivery procedures. There is still considerable controversy concerning the best methods to achieve the strongest porcelain restorations after such adjustments. PURPOSE: The objective of this study was to investigate the effects of (1) overglazing, (2) selfglazing, and (3) fine polishing on the flexural strength and fracture toughness of feldspathic dental porcelain. MATERIAL AND METHOD: Ninety porcelain disks were prepared for flexural strength test and sixty porcelain disks were fabricated for fracture toughness test. Specimens were divided into three groups for each test as follows: 1) overglazed 2) self-glazed 3) polished. The flexural strength of feldspathic porcelains was determined by ring-on-ring biaxial flexural strength test. The fracture toughness values of three experimental groups were obtained by indentation fracture toughness test. RESULTS: The flexural strength of overglazed group was significantly higher than that of selfglazed and polished group (P0.05). The fracture toughness values of overglazed and polished group were significantly higher than that of self-glazed group (P0.05). CONCLUSIONS: This results supported the use of polishing as an alternative to glazing metal ceramic restorations, as it was not detrimental in flexural strength and fracture toughness. But, under the conditions of this study, overglazing was the ideal surface finishing method of feldspathic dental porcelain.