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).FAPESP (Research Support Foundation of the State of Sao Paulo, Brazil)[2007/08140-5, 2008/07403-5

Freqüência de Candida sp. em biópsias de lesões da mucosa bucal

Candidosis is the most common fungal infection in the oral cavity, and is usually associated with local and systemic predisposing factors. The ocurrence and relevance of Candidal infection in oral lesions such as liquen planus, leukoplakias and carcinomas are still to be understood. The aim of the present study was to define the frequency of infection by Candida sp. on biopsies of oral mucosal lesions and associate its presence with malignant and dysplastic lesions. Histopathology reports issued between 1990 and 2001 inclusive were reviewed. Three sections of each mucosal biopsy were stained using the periodic acid-Schiff (PAS) technique. From the 832 biopsies 27.2% were PAS positive, of which 83.25% were obtained from male patients. There was positive association between fungic infection and mild, moderate and severe epithelial dysplasia, squamous cell carcinoma and hiperqueratosis (p < 0.05). There was no association between fungic infection and inflammatory fibrous hyperplasia, hyperkeratosis, lichen planus and pyogenic granuloma (p < 0.05). The frequency of infection in the tongue was significantly higher (p < 0.05) than in the other sites. Our results do not show a causal relation between Candida sp. and dysplastic lesions and carcinomas, but do confirm the higher presence of that microrganism in those lesions.O objetivo desse trabalho foi determinar a freqüência da infecção por Candida sp. em biópsias de lesões da mucosa bucal, assim como associar a presença de Candida sp. com lesões malignas e lesões com vários graus de displasia. Foram utilizadas 832 biópsias da mucosa bucal, previamente incluídas em parafinas, cujos blocos foram obtidos dos arquivos da Disciplina de Patologia da Faculdade de Odontologia de Araraquara da UNESP, no período entre 1990-2001. Três cortes seqüenciais foram corados pelo ácido periódico de Schiff (PAS). Do total de biópsias 27,2% foram PAS positivas, dessas 83,25% eram provenientes de pacientes do sexo masculino. Houve associação positiva entre infecção com displasia epitelial leve, moderada, severa, carcinoma espinocelular e hiperqueratose (p < 0,05). Não houve associação entre hiperplasia fibrosa inflamatória, líquen plano, granuloma piogênico (p < 0,05) com infecções fúngicas. A língua foi o sítio mais acometido por infecções em relação a outros sítios (p < 0,05). A partir dos dados quantitativos, concluiu-se que houve correlação positiva de infecção por fungos, lesões displásicas e carcinoma, sendo mais freqüente no sexo masculino. Estes dados não permitem inferir se o fungo causa displasia epitelial e carcinoma, mas confirmam a maior presença de Candida nessas lesões

The combined use of Er,Cr:YSGG laser and fluoride to prevent root dentin demineralization

The use of erbium lasers to prevent caries in enamel has shown positive results. However, it is not known if Er,Cr:YSGG laser can also be used to increase acid resistance of root dentine, which is another dental tissue susceptible to the action of cariogenic bacteria. Objective: To analyze the effects of the Er,Cr:YSGG laser (λ=2.78 μm, 20 Hz) irradiation associated with 2% neutral sodium fluoride (NaF) to prevent root dentin demineralization. Material and Methods: One hundred human root dentin samples were divided into 10 groups (G) and treated as follows: G1: no treatment; G2: NaF; G3: laser (4.64 J/cm2) with water cooling (WC=5.4 mL/min); G4: laser (4.64 J/cm2) without WC; G5: laser (8.92 J/cm2) with WC; G6: laser (8.92 J/cm2) without WC; G7: laser (4.64 J/cm2) with WC and NaF; G8: laser (4.64 J/cm2) without WC and NaF; G9: laser (8.92 J/cm2) with WC and NaF; G10: laser (8.92 J/cm2) without WC and NaF. The NaF gel was applied alone or after 4 min of irradiation. After 14 days of acid challenge, the samples were sectioned and the Knoop microhardness (KHN) test was done at different depths (30, 60, 90 and 120 μm) from the outer dentin surface. Data were analyzed by one-way ANOVA and Fisher’s test (α=5%). Results: The results showed that G8 and G10 presented higher KHN than the G1 for the depths of 30 and 60 μm, indicating an increase of the acid resistance of the dentin in up to 35% (p<0.05). Conclusions: The use of Er,Cr:YSGG laser irradiation at 4.64 J/ cm2 and 8.92 J/cm2 without water cooling and associated with 2% NaF can increase the acid resistance of human root dentin

Er,Cr:YSGG and 980nm diode lasers influence dentin surface volume after cariogenic challenge: in vitro study

Abstract This study aimed to evaluate the influence of the Er,Cr:YSGG irradiation and 980-nm diode lasers on the surface roughness (SR) and volume loss (VL) of dentin subjected to cariogenic challenge. Subsequently, 130 specimens of bovine dentin were divided into the following 13 groups: NT: no treatment; FG: fluoride gel; FV: fluoride varnish; Di: 980-nm diode; Di + FG; Di + FV; FG + D; FV + Di; Er: Er,Cr:YSGG; Er + FG; Er + FV; FG + Er and FV + Er. Er,Cr:YSGG laser parameters were as follows: 0.25 W; 5.0 Hz; 4.46 J/cm2 without water and 55% air. Furthermore, the 980-nm diode laser parameters were 2.0 W; 2.0 Hz; 21.41 J/cm2. The samples from each group were subjected to pH cycling. A confocal laser scanning microscope was used to evaluate SR and VL. Difference between the volume of the reference and treated areas + DES/RE was used to determine SR and VL. The mean values of the different groups were subjected to analysis of variance and Tukey’s post-hoc test. The VL values were analyzed using the Kruskal–Wallis and Dunn post-hoc test (p 0.05). Moreover, VL in the FV + Di and FV + Er groups showed a statistically significant difference compared with areas submitted to different types of treatment and cariogenic challenge (p > 0.05). Er,Cr:YSGG and 980-nm diode lasers associated with fluoride varnishes decreased dentin VL in bovine teeth submitted to cariogenic challenge

Freqüência de Candida sp. em biópsias de lesões da mucosa bucal

O objetivo desse trabalho foi determinar a freqüência da infecção por Candida sp. em biópsias de lesões da mucosa bucal, assim como associar a presença de Candida sp. com lesões malignas e lesões com vários graus de displasia. Foram utilizadas 832 biópsias da mucosa bucal, previamente incluídas em parafinas, cujos blocos foram obtidos dos arquivos da Disciplina de Patologia da Faculdade de Odontologia de Araraquara da UNESP, no período entre 1990-2001. Três cortes seqüenciais foram corados pelo ácido periódico de Schiff (PAS). do total de biópsias 27,2% foram PAS positivas, dessas 83,25% eram provenientes de pacientes do sexo masculino. Houve associação positiva entre infecção com displasia epitelial leve, moderada, severa, carcinoma espinocelular e hiperqueratose (p < 0,05). Não houve associação entre hiperplasia fibrosa inflamatória, líquen plano, granuloma piogênico (p < 0,05) com infecções fúngicas. A língua foi o sítio mais acometido por infecções em relação a outros sítios (p < 0,05). A partir dos dados quantitativos, concluiu-se que houve correlação positiva de infecção por fungos, lesões displásicas e carcinoma, sendo mais freqüente no sexo masculino. Estes dados não permitem inferir se o fungo causa displasia epitelial e carcinoma, mas confirmam a maior presença de Candida nessas lesões.Candidosis is the most common fungal infection in the oral cavity, and is usually associated with local and systemic predisposing factors. The ocurrence and relevance of Candidal infection in oral lesions such as liquen planus, leukoplakias and carcinomas are still to be understood. The aim of the present study was to define the frequency of infection by Candida sp. on biopsies of oral mucosal lesions and associate its presence with malignant and dysplastic lesions. Histopathology reports issued between 1990 and 2001 inclusive were reviewed. Three sections of each mucosal biopsy were stained using the periodic acid-Schiff (PAS) technique. From the 832 biopsies 27.2% were PAS positive, of which 83.25% were obtained from male patients. There was positive association between fungic infection and mild, moderate and severe epithelial dysplasia, squamous cell carcinoma and hiperqueratosis (p < 0.05). There was no association between fungic infection and inflammatory fibrous hyperplasia, hyperkeratosis, lichen planus and pyogenic granuloma (p < 0.05). The frequency of infection in the tongue was significantly higher (p < 0.05) than in the other sites. Our results do not show a causal relation between Candida sp. and dysplastic lesions and carcinomas, but do confirm the higher presence of that microrganism in those lesions

The combined use of Er,Cr:YSGG laser and fluoride to prevent root dentin demineralization

The use of erbium lasers to prevent caries in enamel has shown positive results. However, it is not known if Er,Cr:YSGG laser can also be used to increase acid resistance of root dentine, which is another dental tissue susceptible to the action of cariogenic bacteria. Objective: To analyze the effects of the Er,Cr:YSGG laser (λ=2.78 μm, 20 Hz) irradiation associated with 2% neutral sodium fluoride (NaF) to prevent root dentin demineralization. Material and Methods: One hundred human root dentin samples were divided into 10 groups (G) and treated as follows: G1: no treatment; G2: NaF; G3: laser (4.64 J/cm2) with water cooling (WC=5.4 mL/min); G4: laser (4.64 J/cm2) without WC; G5: laser (8.92 J/cm2) with WC; G6: laser (8.92 J/cm2) without WC; G7: laser (4.64 J/cm2) with WC and NaF; G8: laser (4.64 J/cm2) without WC and NaF; G9: laser (8.92 J/cm2) with WC and NaF; G10: laser (8.92 J/cm2) without WC and NaF. The NaF gel was applied alone or after 4 min of irradiation. After 14 days of acid challenge, the samples were sectioned and the Knoop microhardness (KHN) test was done at different depths (30, 60, 90 and 120 μm) from the outer dentin surface. Data were analyzed by one-way ANOVA and Fisher’s test (α=5%). Results: The results showed that G8 and G10 presented higher KHN than the G1 for the depths of 30 and 60 μm, indicating an increase of the acid resistance of the dentin in up to 35% (

Factors affecting the placement or replacement of direct restorations in a dental school

Context: The knowledge of the reasons for the placement of direct restorations makes possible to trace an epidemiological profile of a specific population and to direct the teaching of dentistry to techniques that are commonly used today and will be continued performed in the future. Purpose: The aim of this study was to verify the reasons for placement and replacement of direct restorations in patients treated in the Dental Clinic of the Uberaba University - Brazil. Materials and Methods: This study evaluated 306 restorative procedures carried out on 60 patients. During the treatment planning, a form that contained information about the patient′s gender, tooth number, the classification of restorations, the reasons for placement and replacement of amalgam and tooth-colored restorations, the material that had to be removed and the new material used to fill the cavities was filled for each patient. Statistical analysis was carried out using Chi-square test (α = 0.05). Results: The data showed that most of the patients were female (66.7%). Of all the restorations placed, 60.45% were 1 st -time placements, while 39.55% were replacements. For 1 st -time restorations, the main reason for placement was primary caries (76.76%), followed by non-carious cervical lesions (15.14%). The amalgam restorations were replaced more frequently (67.77%). The primary reason for replacements was the presence of secondary caries (for both previous amalgam (42.68%) and composite (66.67%) restorations (P < 0.05). The resin composite was the most indicated material for the new restorations (98.04%) (P < 0.05). Conclusions: The main reason for placement of direct restorations was primary caries, while secondary caries was the main reason for replacements. In almost all cases, the material used to fill the cavities was the resin composite

Analysis of colostrum IgA against bacteria involved in neonatal infections

<div><p>ABSTRACT Objective To describe e compare the specificity of IgA antibodies against bacteria extract of Klebsiella pneumoniae , Staphylococcus aureus , Escherichia coli , and Salmonella enteritidis . Methods Colostrum samples were aseptically collected in the first 12 hours after C-section delivery. The specificity of IgA against bacteria extracts was analyzed by the Western blot. Results The findings showed proteins of high molecular weight frequently detectable in the samples. S. aureus was the most frequently found bacterium in the samples (p<0.05). Approximately 93.8, 56.3, 62.5 and 60.4% of samples presented IgA reactive to S. aureus , K. pneumoniae , S. enteritidis, and E. coli, respectively. Roughly 40% of samples showed no IgA reactive to K. pneumoniae, S. enteritidis and E. coli . Conclusion Clinical evidence of the importance of breastfeeding for the immune protection of neonates was consistent with the observed immunological findings, since most samples showed IgA reactive against the species tested. The application and development of immunotherapies during pregnancy, focused on frequently detected antigens, could be an important tool to enhance the presence of IgA in colostrum.</p></div