Temperature variation at the external root surface during 980-nm diode laser irradiation in the root canal

Objective: To assess the temperature variation in the cervical, middle and apical thirds of root external wall, caused by 980-nm diode laser irradiation with different parameters. Methods: The roots of 90 canines, had their canals instrumented and were randomly distributed into 3 groups (n = 30) according to the laser potency (1.5 W, 3.0 W and 5.0 W). Each group was subdivided into 3 (n = 10) according to the frequency (CM, 100 Hz and 1000 Hz), and each subgroup divided into 2 (n = S): dried canal or filled with distilled water. The maximum temperature values were collected by 3 thermocouples located at each third of the root external wall and recorded by digital thermometers. Results: The groups irradiated in the continuous mode (CM) presented the highest values (11.82 +/- 5.78), regardless of the canals were dry or not, which were statistically different (p < 0.01) from those obtained with 100 Hz (6.22 +/- 3.64) and 1000 Hz (6.00 +/- 3.36), which presented no statistical difference between them (p > 0.01). The groups irradiated with 5.0 W presented the greatest temperature variation (12.15 +/- 5.14), followed by 3.0 W (7.88 +/- 3.92) and 1.5 W (4.02 +/- 2.16), differing between them (p < 0.01). The cervical third of the root presented the highest temperature rises (9.68 +/- 5.80), followed by the middle (7.66 +/- 4.87) and apical (6.70 +/- 4.23), with statistical difference among them (p < 0.01). After 30 s from the end of irradiation, all the specimens presented temperature variation lower than 10 degrees C. Conclusions: Application of 980-nm diode laser in the root, at 1.5 W in all operating modes, and 3.0 W, in the pulsed mode, for 20 s, can safely be used in endodontic treatment, irrespective of the presence of humidity. (C) 2008 Elsevier Ltd. All rights reserved

Histological and thermometric examination of soft tissue de-epithelialization using digitally controlled Er:YAG laser handpiece: an ex vivo study

Abstract OBJECTIVE: The purpose of this study was histological and thermometric examination of soft tissue de-epithelialization using digitally controlled laser handpiece (DCLH) - X-Runner. BACKGROUND DATA: Commonly used techniques for de-epithelialization include scalpel, abrasion with diamond bur, or a combination of the two. Despite being simple, inexpensive and effective, these techniques are invasive and may produce unwanted side effects. It is important to look for alternative techniques using novel tools, which are minimally invasive and effective. MATERIALS AND METHODS: 114 porcine samples sized 6 × 6 mm were collected from the attached gingiva (AG) of the alveolar process of the mandible using 15C scalpel blade. The samples were irradiated by means of Er:YAG laser (LightWalker, Fotona, Slovenia), using X-Runner and HO2 handpieces at different parameters; 80, 100, and 140 mJ/20 Hz in time of 6 or 16 sec, respectively. The temperature was measured with a K-type thermocouple. For the histopathological analysis of efficiency of epithelium removal and thermal injury, 3 random samples were de-epithelialized with an HO2 handpiece, and 9 random samples with an X-Runner handpiece with different parameters. For the samples irradiated with DCLH, we have used three different settings, which resulted in removing 1 to 3 layers of the soft tissue. The efficiency of epithelium removal and the rise of temperature were analyzed. RESULTS: DCLH has induced significantly lower temperature increase compared with HO2 at each energy to frequency ratio. The histological examination revealed total epithelium removal when HO2 handpiece was used at 100 and 140 mJ/20 Hz and when DCLH was used for two- and threefold lasing at 80, 100, and 140 mJ/20 Hz. CONCLUSIONS: Er:YAG laser with DCLH handpiece may be an efficient tool in epithelium removal without excessive thermal damage

Bond strength of AH Plus and Epiphany sealers on root dentine irradiated with 980 nm diode laser

Aim To evaluate the bond strength of AH Plus and Epiphany sealers to human root canal dentine irradiated with a 980 nm diode laser at different power and frequency parameters, using the push-out test. Methodology Sixty canine roots were sectioned below the cementoenamel junction to provide 4-mm-thick dentine discs that had their root canals prepared with a tapered bur and irrigated with sodium hypochlorite, ethylenediaminetetraacetic acid and distilled water. The specimens were assigned to five groups (n = 12): one control (no laser) and four experimental groups that were submitted to 980 nm diode laser irradiation at different power (1.5 and 3.0 W) and frequency (continuous wave and 100 Hz) parameters. Half of specimens in each group had their canals filled with AH Plus sealer and half with Epiphany. The push-out test was performed and data (MPa) were analysed statistically by ANOVA and Tukey`s test (P < 0.05). The specimens were split longitudinally and examined under SEM to assess the failure modes after sealer displacement. Results The specimens irradiated with the diode laser and filled with AH Plus had significantly higher bond strength values (8.69 +/- 2.44) than those irradiated and filled with Epiphany (3.28 +/- 1.58) and the nonirradiated controls (3.86 +/- 0.60). The specimens filled with Epiphany did not differ significantly to each other or to the control (1.75 +/- 0.69). There was a predominance of adhesive failures at Epiphany-dentine interface (77%) and mixed failures at AH Plus-dentine interface (67%). Conclusions The 980 nm diode laser irradiation of root canal dentine increased the bond strength of AH Plus sealer, but did not affect the adhesion of Epiphany sealer

Association phenothiazine and laser on growth of C. tropicalis fluconazole-resistant

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2014-05-12T18:55:12Z No. of bitstreams: 1 Gomes Jr. R.A Association....pdf: 364291 bytes, checksum: 113b6ad435ddf4434415ad459c4cacce (MD5)Made available in DSpace on 2014-05-12T18:55:12Z (GMT). No. of bitstreams: 1 Gomes Jr. R.A Association....pdf: 364291 bytes, checksum: 113b6ad435ddf4434415ad459c4cacce (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório de Biologia Parasitária. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, BrasilCenter of Biophotonic, School of Dentistry. Federal University of Bahia. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, BrasilCenter of Biophotonic, School of Dentistry. Federal University of Bahia. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, Brasil / Department of Biology. Estate University of Feira de Santana. Feira de Santana, BA, BRasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório de Biologia Parasitária. Salvador, BA, BrasilCenter of Biophotonic, School of Dentistry. Federal University of Bahia. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, BrasilCenter of Biophotonic, School of Dentistry. Federal University of Bahia. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, BrasilCenter of Biophotonic, School of Dentistry. Federal University of Bahia. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, Brasil / Brugnera & Zanin Institute. São Paulo, SP, BRasilCenter of Biophotonic, School of Dentistry. Federal University of Bahia. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, Brasil / Brugnera & Zanin Institute. São Paulo, SP, BRasilCenter of Biophotonic, School of Dentistry. Federal University of Bahia. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, Brasil / Brugnera & Zanin Institute. São Paulo, SP, BRasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório de Biologia Parasitária. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, BrasilCandidiasis is caused by Candida species found on the skin, gastrointestinal tract and mucous cavities of the humans and may be acute, chronic, localized or systemic. Alhough C. albicans is the species most often identified as responsible for this type of infection C. Tropicalis has been considered an emerging cause. The effect of the association of phenothiazine - PTZ and laser on fluconazole-resistant C.tropicalis growth was tested. 2.5 x 106 CFU/mL 100mg/mL of phenothiazine with the pre-irradiation time of 10 min were irradiated with laser light (660 nm; 4.8 and 12 J/cm2 (L1 and L2 respectively) 40 mW) followed by incubation in RPMI for 24h. The following conditions were tested: control (control), laser (L1 and L2), phenothiazine (F1 and F2), and PACT (F1L1 and F2L2). Statistically significant diferences were seen between groups (L-F +) and (F + L +) for both conditions of the laser, with a growth inhibition of the yeast around 67 and 51%, respectively, however, when using only the laser there was an increase of 18% in the survival of these cells. PACT´s efficacy on fluconazole-resistant C. tropicalis depended on both the time of pre-irradiation and concentration of the PTZ

In vitro influence of photodynamic antimicrobial chemotherapy on staphylococcus aureus by using phenothiazines derivatives associated with laser/LED Light

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2014-05-09T17:04:24Z No. of bitstreams: 1 De Oliveira In vitro influence....pdf: 315457 bytes, checksum: 703ffce73bb49c9c5043e50c5734ef5a (MD5)Made available in DSpace on 2014-05-09T17:04:24Z (GMT). No. of bitstreams: 1 De Oliveira In vitro influence....pdf: 315457 bytes, checksum: 703ffce73bb49c9c5043e50c5734ef5a (MD5) Previous issue date: 2014Federal University of Bahia. Center of Biophotonic. School of Dentistry. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, BrasilFederal University of Bahia. Center of Biophotonic. School of Dentistry. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, Brasil / Estate University of Feira de Santana. Department of Biology. Feira de Santana, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório de Biologia Parasitéria. Salvador, BA, Brasil / School of Medicine. Universidade Federal da Bahia. Salvador, BA, Brasil / School of Medicine and Public Health. FDC. Salvador, BA, BrasilFederal University of Bahia. Center of Biophotonic. School of Dentistry. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório de Biologia Parasitéria. Salvador, BA, Brasil / School of Medicine. Universidade Federal da Bahia. Salvador, BA, Brasil / School of Medicine and Public Health. FDC. Salvador, BA, BrasilFederal University of Bahia. Center of Biophotonic. School of Dentistry. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, BrasilFederal University of Bahia. Center of Biophotonic. School of Dentistry. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, Brasil / Brugnera & Zanin Institute. São Paulo, SP, BrasilFederal University of Bahia. Center of Biophotonic. School of Dentistry. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, Brasil / Brugnera & Zanin Institute. São Paulo, SP, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório de Biologia Parasitéria. Salvador, BA, BrasilFederal University of Bahia. Center of Biophotonic. School of Dentistry. Salvador, BA, Brasil / National Institute of Optics and Photonics. São Carlos, SP, Brasil / Brugnera & Zanin Institute. São Paulo, SP, BrasilThe aim of this study was to evaluate the effect of photodynamic antimicrobial chemotherapy (PACT) using phenothiazinium dyes - PTZ irradiated with red laser (ʎ660nm) or red-orange LED (ʎ632±2nm) on Staphylococcus aureus in vitro. triplicate tests were performed in 10 groups: control, Laser (L1+P- and L2+P-) bacterial suspensions were irradiated only with laser energy 2.4 and 4.8 J/cm2 respectively, (Led1+P- and Led2+P-) irradiated only with LED energy 2.4 and 4.8 J/cm2 respectively, (L1+P+ and L2+P+) irradiated with laser in the presence of 1μg/ml of photosensitizer, (Led1+P+ and Led2+P+) irradiated with LED in the presence of 1μg/ml of photosensitizer and finally (L-P+) only in the presence of PTZ dye. Bactericidal effect of the PACT was assessed by counting colony-forming units. The results showed no significant difference on regards different energy densities on group PACT for both lights. PACT groups (L2+P+ and Led2+P+) compared to the Control showed significant reduction of CFUs. LED/Laser groups (L2+P- and Led2+P-) compared to control and PTZ groups showed also significant differences as groups LED/Laser (4.8J/cm2) increased the average of CFUs. Although the results of this study have shown a reduction in average number of colonyforming units by the appropriate Laser or LED-dye treatment combination, it this topic requires further investigation