Upconversion of infrared-to-visible light in Pr3+-Yb3+ codoped fluoroindate glass

Bright fluorescence in the visible range has been observed in Pr3+-Yb3+ doped fluoroindate glass under infrared diode laser irradiation. The mechanism which contributes for the upconversion emission is identified and the energy transfer rate between Pr3+-Yb3+ is obtained for different concentrations. © 1998 Elsevier Science B.V. All rights reserved.

Effect of antimicrobial photodynamic therapy on periodontally infected tooth sockets in rats

The aim of the present study was to evaluate the antimicrobial effect of antimicrobial photodynamic therapy (aPDT) in alveolar treatment of areas with induced periodontitis. Thirty male Wistar rats were subjected to ligature-induced periodontal disease (PD) in the first left inferior molars, while the right side molars did not receive ligatures. After 7 days of PD evolution, ligatures were removed from the left side, and the first left and right mandibular molars were extracted. Afterwards, animals were divided into groups according to the following treatments: control (C)-no treatment; mechanical debridement (MD)-mechanical debridement and irrigation with saline solution; and aPDT-mechanical debridement, irrigation with toluidine blue O (TBO), and 1 min of laser irradiation (GaAlAs, 660 nm, 30 mW, 32 J/cm2, 60 s). Ligatures were removed and samples of the alveolar content after extraction and after each treatment were collected for microbial processing by real-time polymerase chain reaction with specific primers for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Treponema denticola. Data were submitted to statistical analysis by multiple comparison tests (McNemar test; p < 0.05). T. denticola was not found in the collected samples. A. actinomycetemcomitans and P. gingivalis were found in ligature samples. Tooth socket samples without periodontitis induction presented lesser microbial charge than samples with induced periodontitis (p < 0.05). aPDT significantly reduced A. actinomycetemcomitans levels on the left side (p < 0.05). It was concluded that aPDT was an effective antimicrobial treatment for tooth sockets in areas affected by induced periodontitis. © 2013 Springer-Verlag London.

Resistência à cárie de esmalte dental irradiado por lasers de Er:YAG e Nd:YAG, avaliada através da morfologia e proporção Ca/P

Pós-graduação em Ciências Odontológicas - FOAR

Efeitos da terapia fotodinâmica na expressão dos genes SAP5, LIP9 e PLB2 em Candida albicans

Pós-graduação em Biopatologia Bucal - ICT

Effect of Dental Surface Treatment with Nd:YAG and Er:YAG Lasers on Bond Strength to Recently Bleached Dentin

The objective of this study was to evaluate the effect of surface treatment with Er:YAG and Nd:YAG lasers on resin composite bond strength to recently bleached dentin. A total of 120 bovine incisors were distributed into two groups: C- without bleaching; and B- bleached with 35% hydrogen peroxide. Each group was divided into three subgroups: N- without laser treatment; Nd- Nd:YAG laser irradiation; and Er- Er:YAG laser irradiation. The adhesive system (Adper Single Bond 2) was applied and composite build-ups were constructed with Filtek Supreme (3M/ESPE). The teeth were sectioned to obtain dentin-resin sticks (1x1mm(2)) and tested by microtensile bond testing. The bond strength values in group B, subgroup N (16.1 +/- 3.5MPa) presented no significant difference compared with group B, subgroup Er (14.7 +/- 6.1MPa). Group C, subgroup N (26.8 +/- 7.4MPa) presented no significant difference compared with group B, subgroup Nd (28.8 +/- 5.6MPa). Group C, subgroup Nd (36.1 +/- 7.9MPa) presented a significant increase in bond strength compared with the other groups. The Er:YAG laser did not influence the bond strength of bleached specimens, and the use of the Nd:YAG laser on bleached specimens was able to reverse the immediate effects of bleaching, obtaining bond strength values similar to those of the control group.

Dentin Bond Strength: Influence of Er:YAG and Nd:YAG Lasers

The aim of this study was to investigate the effects of Er:YAG and Nd:YAG lasers on the shear bond strength of composite resin to dentin. The coronal portion of 56 human molars was divided into three parts, and the dentin thickness was standardized at 2 mm. A 3-mm hole was marked in the center of each tooth with sealing tape paper. The specimens (n = 14) were then divided into four groups: (1) acid etching + Single Bond (SB) (control), (2) acid etching + SB + Nd: YAG laser irradiation (before adhesive curing), (3) thermal etching with the Er: YAG laser + SB, and (4) thermal etching with the Er: YAG laser + SB + Nd: YAG laser irradiation (before adhesive curing). A composite resin cylinder was built into the delimited area for conducting the shear bond strength test on the universal testing machine. The means +/- standard deviations were: group 1, 17.05 +/- 4.15 MPa; group 2, 16.90 +/- 3.36 MPa; group 3, 12.12 +/- 3.85 MPa; and group 4, 12.92 +/- 2.73 MPa. Groups 1 and 2 presented significantly higher values than groups 3 and 4. It was concluded that conventional etching with 37% phosphoric acid yielded significantly higher bond strength values compared to thermal etching with the Er:YAG laser. The Nd:YAG laser did not significantly influence the bond strength.

Resposta de fibroblastos da gengiva de pacientes jovens e idosos e efeito da laserterapia de baixa potência e de fator de crescimento sobre estas células

Pós-graduação em Reabilitação Oral - FOAR

Evaluation of gene expression SAP5, LIP9, and PLB2 of candida albicans biofilms after photodynamic inactivation

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

Comparison of Different Dentin Pretreatment Protocols on the Bond Strength of Glass Fiber Post Using Self-etching Adhesive

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

Adaptation and penetration of resin-based root canal sealers in root canals irradiated with high-intensity lasers

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

Surface morphology and structural modification induced by femtosecond pulses in hydrogenated amorphous silicon films

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

Dentin bond strength: influence of Er:YAG and Nd:YAG lasers

The aim of this study was to investigate the effects of Er:YAG and Nd:YAG lasers on the shear bond strength of composite resin to dentin. The coronal portion of 56 human molars was divided into three parts, and the dentin thickness was standardized at 2 mm. A 3-mm hole was marked in the center of each tooth with sealing tape paper. The specimens (n = 14) were then divided into four groups: (1) acid etching + Single Bond (SB) (control), (2) acid etching + SB + Nd:YAG laser irradiation (before adhesive curing), (3) thermal etching with the Er:YAG laser + SB, and (4) thermal etching with the Er:YAG laser + SB + Nd:YAG laser irradiation (before adhesive curing). A composite resin cylinder was built into the delimited area for conducting the shear bond strength test on the universal testing machine. The means ± standard deviations were: group 1, 17.05 ± 4.15 MPa; group 2, 16.90 ± 3.36 MPa; group 3, 12.12 ± 3.85 MPa; and group 4, 12.92 ± 2.73 MPa. Groups 1 and 2 presented significantly higher values than groups 3 and 4. It was concluded that conventional etching with 37% phosphoric acid yielded significantly higher bond strength values compared to thermal etching with the Er:YAG laser. The Nd:YAG laser did not significantly influence the bond strength.

Radiographic assessment of potodynamic therapy as an adjunctive treatment on induced periodontitis in immunosupressed rats

OBJECTIVE: The aim of this study was to assess radiographically the effect of photodynamic therapy (PDT) as an adjunctive treatment to scaling and root planing (SRP) on induced periodontitis in dexamethasone-induced immunosuppressed rats. MATERIAL AND METHODS: The animals were divided into 2 groups: ND group (n=60): saline treatment; D group (n=60): dexamethasone treatment. In both ND and D groups, periodontal disease was induced by the placement of a ligature in the left first mandibular molar. After 7 days, ligature was removed and all animals received SRP, being divided according to the following treatments: SRP: saline and PDT: phenothiazinium dye (TBO) plus laser irradiation. Ten animals per treatment were killed at 7, 15 and 30 days. The distance between the cementoenamel junction and the height of the alveolar bone crest in the mesial surface of the mandibular left first molars was determined in millimeters in each radiograph. he radiographic values were analyzed statistically by ANOVA and Tukey's test at a p value <0.05. RESULTS: Intragroup radiographic assessment (ND and D groups) showed that there was statistically signifcant less bone loss in the animals treated with PDT in all experimental periods compared to those submitted to SRP. Intergroup radiographic analysis (ND and D groups) demonstrated that there was greater bone loss in the ND group treated with SRP compared to the D group treated with PDT at 7 and 30 days. CONCLUSION: PDT was an effective adjunctive treatment to SRP on induced periodontitis in dexamethasone-induced immunosuppressed rats.

Treatment of experimental periodontal disease by antimicrobial photodynamic therapy in nicotine-modified rats

Background The aim of this study was to compare antimicrobial photodynamic therapy (aPDT) as an adjunctive treatment to scaling and root planing (SRP) for induced periodontitis in nicotine-modified rats. Material & Methods A total of 240 rats were evenly divided into two groups: C – saline solution treatment; N – nicotine treatment. Periodontal disease was induced in both groups at the first mandibular molar. After 7 days, the ligature was removed. All animals were submitted to SRP and were divided according to the following treatments: SRP – irrigation with saline solution; Toluidine Blue-O (TBO) – irrigation with phenothiazinium dye (100 μg/ml); LLLT – laser irradiation (660 nm; 0.03 W; 4 J); and aPDT – TBO and laser irradiation. Ten animals in each group/treatment were euthanized at 7, 15 and 30 days. The histometric and immunohistochemical values were statistically analysed. Results Intragroup analysis demonstrated that in both groups the aPDT treatment resulted in lower bone loss (BL) when compared to SRP in all experimental periods. Intergroup analysis demonstrated that aPDT treatment resulted in lower BL in Group N than in Group C treated with SRP in all experimental periods. Conclusion Antimicrobial photodynamic therapy was an effective adjunctive treatment to SRP for induced periodontitis in nicotine-modified rats.

Efeitos de lasers de alta potência na superfície de cerâmicas vítreas de dissilicato de lítio e sua resistência de união à dentina humana

Pós-graduação em Odontologia Restauradora - ICT