Microleakage in indirect onlay restorations cemented with three different types of adhesives: an in vitro study

To evaluate the in vitro degree of marginal microleakage in indirect Class II onlay restorations cemented with dual self-adhesive, universal adhesive and dual adhesive.In the present in vitro experimental study, a total of 54 human premolar teeth were prepared and divided into three equal groups (n = 18) for placement of onlay-type restorations cemented with A: Allcem™ dual-cure adhesive cement), B: RelyX™U200 dual-cure self-adhesive cement and C: RelyX™ Ultimate universal adhesive cement. All restorations were subjected to 10,000 thermocycles between 5°C and 55°C and immersed in a 1M silver nitrate solution for 6 hours. The crowns were then sectioned mesiodistally and observed under a stereo microscope to determine the degree of marginal microleakage in the cervical area.The onlay restorations cemented with RelyX Ultimate did not present microleakage in the majority of cases (77.8%). Restorations cemented with RelyX U200 showed predominantly microleakage up to the pulp floor in 83.3% of the total, being this significantly higher microleakage than in restorations cemented with RelyX Ultimate and Allcem Dual (p<0.001 and p<0.001 respectively). There was no significant difference in microleakage between the last two mentioned cements (p=0.255) Allcem dual adhesive cement and RelyX Ultimate universal adhesive showed significantly less microleakage than RelyX U200 dual-curing self-adhesive cement at the cervical level, with predominantly no microleakage and microleakage down to the enamel, respectively. The use of RelyX Ultimate cement in indirect restorations is recommended as it showed better marginal adaptation

"In Vitro Color Stability Evaluation of Three Polished and Unpolished Nanohybrid Resin Composites Immersed in a 0.12% Chlorhexidine-Based Mouthwash at Different Times"

"The use of chlorhexidine-based mouthwashes on resin composites with rough surfaces can cause discoloration which compromises the esthetic of patients. The present study aimed to evaluate the in vitro color stability of Forma (Ultradent Products, Inc., South Jordan), Tetric N-Ceram (Ivoclar Vivadent, Schaan, Liechtenstein) and Filtek Z350XT (3M, ESPE, St. Paul, MN, USA) resin composites, with and without polishing, after being immersed in a 0.12% chlorhexidine (CHX)-based mouthwash at different times. The present in vitro experimental and longitudinal study used 96 nanohybrid resin composite blocks (Forma, Tetric N-Ceram and Filtek Z350XT) 8 mm in diameter and 2 mm thick, evenly distributed. Each resin composite group was divided into two subgroups (n = 16) with and without polishing and then immersed in a 0.12% CHX-based mouthwash for 7, 14, 21 and 28 days. Color measurements were performed with a calibrated digital spectrophotometer. Nonparametric tests were used to compare independent (Mann–Whitney U and Kruskal–Wallis) and related (Friedman) measures. In addition, the Bonferroni post hoc correction was used considering a significance level of p < 0.05. All polished and unpolished resin composites presented color variation < 3.3 when immersed for up to 14 days in 0.12% CHX-based mouthwash. The polished resin composite with the lowest color variation (∆E) values over time was Forma, and the one with the highest values was Tetric N-Ceram. When comparing the color variation (∆E) over time, it was observed that the three resin composites, with and without polishing, presented a significant change (p < 0.001), although these changes in color variation (∆E) were evident from 14 days between each color acquisition (p < 0.05). The unpolished Forma and Filtek Z350XT resin composites showed significantly more color variation than the same polished ones at all times when immersed in a 0.12% CHX-based mouthwash for 30 s daily. In addition, every 14 days, all three resin composites with and without polishing showed a significant color change, while, every 7 days, color stability was maintained. All the resin composites showed clinically acceptable color stability when exposed for up to 14 days to the above-mentioned mouthwash.

Aspectos citopatológicos y quirúrgicos de la lesión intraepitelial de alto grado en el servicio de Ginecología del Hospital Guillermo Almenara Essalud.

TesisEn un estudio transversal de 174 pacientes operadas de cono frio se evaluó las características citopatológicas y quirúrgicas encontrando mayor prevalencia entre los 30 a 44 años (58.4%). La prevalencia de la lesión intraepitelial de alto grado (LIEAG) en el Papanicolaou fue de 75.4%. Los resultados de biopsia dirigida por colposcopia advierten que el 90.9% fue LIEAG. De la histopatología de cono, 73.6% fue LIEAG. El compromiso de bordes del cono cervical fue de 9.2% del exocervix y endocervix cada uno respectivamente y 3.5% de ambos márgenes. El Pap presentó una sensibilidad 84.7%,una especificidad de 19.2%, un valor predictivo positivo de 82.6% y un valor predictivo negativo de 21.7% respecto del cono. La biopsia tuvo una sensibilidad de 96.1%,una especificdad de 9.8%, un valor predictivo positivo de 76.7% y un valor predictivo negativo de 44.4% respecto del cono. La sensibilidad del Pap fue de 81.5%, la especificidad de 22.2%,el valor predictivo positivo de 94.4% y el valor predictivo negativo de 6.9% respecto a la biopsia. La concordancia del resultado histopatológico de la biopsia con el cono fue del 42%, un sobrediagnóstico de 31% y un infradiagnóstico de 27%

Evaluación antibacteriana del peróxido de hidrógeno comparado con hipoclorito de sodio sobre cepillos dentales inoculados con Streptococcus mutans

Objective: To assess the antibacterial effect of 6% hydrogen peroxide (H2O2) compared with 1% and 2% sodium hypochlorite, on toothbrushes inoculated with Streptococcus mutans ATCC® 25175™. Materials and methods: The study design was an experimental in vitro, cross-sectional prospective and comparative study. Sixty toothbrushes were used, which were divided into four groups of 15 brushes. After conducting a pilot study, the sample number was determined by the means comparison formula and these were selected by simple random sampling. These brushes were inoculated with strains of S. mutans ATCC® 25175™. The disinfectants included H2O2 at 6% and sodium hypochlorite (NaOCl) at 1% and 2%. The Shapiro–Wilk test was used to assess normality and the Mann-Whitney U test was applied for the hypothesis test. Results: The 6% H2O2 showed an average growth of 2 × 109 CFU/mL, which indicates that its effectiveness is greater compared to the 1% NaClO that showed a growth average of 4 × 109 CFU/mL which is less than the 2% NaClO that presented 0 CFU/mL of S. mutans (p = 0.004). Conclusion: Between 6% H2O2 and 1% and 2% NaClO, specifically antibacterial detection, 2% NaClO was concluded as being the most effective.Objetivo: avaliar o efeito antibacteriano do peróxido de hidrogênio 6% em comparação ao hipoclorito de sódio 1% e 2%, em escovas de dente inoculadas com Streptococcus mutans ATCC® 25175™. Materiais e métodos: estudo experimental in vitro, transversal e comparativo. Foram utilizadas 60 escovas de dente, as quais foram divididas em 4 grupos de 15 escovas cada um. O número amostral foi determinado pela fórmula de comparação de médias, após realização de um estudo piloto, sendo selecionado por meio de amostragem aleatória simples. As escovas foram inoculadas com cepas de Streptococcus mutans ATCC® 25175™. Os desinfetantes utilizados foram peróxido de hidrogênio (H202) 6% em comparação ao hipoclorito de sódio (NaClO) 1% e 2%. Aplicou-se a prova de normalidade de Shapiro-Wilk e como teste de hipótese utilizou-se o U de Mann-Whitney. Resultados: o H202 6% apresentou uma média de crescimento de 2.109 UFC/mL, indicando uma efetividade maior em comparação com o NaClO 1% que apresentou uma média de crescimento de 4.109 UFC/mL, que por sua vez foi menos efetivo que o NaClO 2% que apresentou uma contagem de 0 UFC/mL de Streptococcus mutans (p=0,004). Conclusão: o H2O2 6% e o NaClO 1% e 2%, apresentaram efetividade antibacteriana, sendo que o NaClO 2% foi totalmente efetivo.Objetivo: evaluar el efecto antibacteriano del peróxido de hidrógeno (H2O2) al 6 % comparado con hipoclorito de sodio (NaClO) al 1 % y al 2 %, sobre cepillos dentales inoculados con Streptococcus mutans atcc® 25175™. Materiales y métodos: estudio experimental in vitro, transversal y comparativo. Se utilizaron 60 cepillos dentales, divididos en 4 grupos de 15 cepillos cada uno. El número de muestra lo determinó la fórmula de comparación de medias, después de realizar un estudio piloto, y se seleccionaron por muestreo aleatorio simple. Se aplicaron las pruebas de normalidad de Shapiro-Wilk, y para la prueba de hipótesis, la U de Mann-Whitney. Resultados: el H2O2 al 6 % presentó una media de crecimiento de 2 × 109 UFC/mL, lo que indica que su efectividad es mayor comparada con el NaClO al 1 %, que presentó una media de crecimiento de 4 × 109 UFC/mL, y esta es menor al NaClO al 2 %, que tuvo 0 UFC/mL de Streptococcus mutans (p = 0,004). Conclusión: el H2O2 al 6 % y el NaClO al 1 % y al 2 % evidenciaron efectividad antibacteriana, aun cuando fue el NaClO al 2 % el más efectivo

The Microhardness and Surface Roughness Assessment of Bulk-Fill Resin Composites Treated with and without the Application of an Oxygen-Inhibited Layer and a Polishing System: An In Vitro Study

The aim of this study was to assess the microhardness and surface roughness of bulk-fill resin composites treated with and without the application of an oxygen-inhibited layer (OIL) and a polishing system. This in vitro experimental study consisted of 72 resin composite blocks divided into three groups: Tetric N-Ceram Bulk Fill, Opus Bulk Fill APS, and Filtek Bulk Fill. Each resin composite group was further divided into two subgroups: with and without OIL control. Subsequently, surface roughness and microhardness were measured before and after polishing. A t-test was used to compare independent and related measures. For the intergroup comparison of variation before and after polishing, the Kruskal&ndash;Wallis test with Bonferroni post hoc was used considering a significance level of p &lt; 0.05. When comparing surface roughness, significant differences were observed between Opus Bulk Fill resin composite with and without OIL control (p = 0.003) before polishing. The same occurred when comparing Tetric N-Ceram resin composite with and without OIL control (p = 0.039) after polishing. In addition, the surface roughness of Filtek Bulk Fill, Opus Bulk Fill, and Tetric N-Ceram Bulk Fill resin composites, with and without OIL control, decreased significantly after polishing (p &lt; 0.001), while surface microhardness significantly increased (p &lt; 0.05), with the exception of Opus Bulk Fill resin with OIL control (p = 0.413). In conclusion, OIL control and polishing significantly improved the surface roughness and surface microhardness of Filtek Bulk Fill and Tetric N-Ceram Bulk Fill resin composites. However, in the case of Opus Bulk Fill resin composite, only its surface roughness was significantly improved