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Purpose: The aim of this study was to analyze the interaction between the high-power diode laser and the dental root surface. Materials and Methods: Twenty-one single-rooted teeth were divided into 3 experimental groups. Group 1: Root surfaces were treated with scaling and root planing followed by high-power diode laser irradiation in the gated-pulsed mode (wavelength 808 nm, 400 μm optical fiber used parallel to the root surface, 1.5 W for 30 s, 10 Hz, pulse width of 50 μs). Group 2: Root surfaces were treated as in group 1, but irradiated in the continuous-wave mode. Group 3: Control - scaling and root planing using a Gracey curette. The temperature variation, root surface morphology, and proliferation of fibroblasts cultured on the root surfaces were analyzed. Results: There was an increase in temperature within the biological safety limits; it was significantly higher for group 2. Irradiation modified the smear layer, which exhibited rough areas intermingled with smooth areas. Open dentinal tubules were not observed. The fibroblasts proliferated throughout the experimental time (0 to 3 days). The growth curves of all groups were similar. Conclusion: Under the conditions of this study, we concluded that the use of high-power diode laser for root-surface conditioning is thermally safe and causes similar superficial morphological changes independent of the irradiation mode used. Additionally, these lased root surfaces are biocompatible, because cell adhesion and growth were not impaired. [ABSTRACT FROM AUTHOR]

Purpose: Temperature rises in the pulp chamber of more than 5.5°C during cavity preparation are considered harmful to the pulp vitality. This study evaluated the safety and effectiveness of the Er:YAG laser for cavity preparation using two different parameters on human enamel and dentin in vitro. Materials and Methods: Eight extracted human maxillary incisors were used. Thermocouples were inserted into the root canals until they reached the pulp chamber to measure temperature during cavity preparation. For all teeth, the thickness was measured both on the buccal and the lingual surfaces before preparation. Periapical radiographs were taken to confirm these thickness values. Two groups (G1, G2) of 4 teeth each were formed. Class V cavities on buccal and lingual surfaces in enamel and dentin were prepared with an Er:YAG laser with a 1.0-mm-diameter tip under air-water cooling. The parameters were as follows: G1: 10 Hz, 500 mJ; G2: 10 Hz, 850 mJ. The pulses were also measured during each preparation. To compare the two parameters, SEM analysis was conducted to evaluate morphological changes in dentin. Results: This study showed temperature rises of less than 3°C in all cavity preparations in both groups. Conclusion: Our data indicate that the parameters chosen for Class V cavity preparation are safe and also effective for use in human teeth. Furthermore, cavity preparation with the Er:YAG laser with both energy parameters was very fast. [ABSTRACT FROM AUTHOR]

Purpose: The use of high-dose chemotherapy as part of the preparative regimen for stem cell transplantation is associated with mucosal damage. Laser irradiation of the oral mucosa may help to decrease the severity of mucositis. This pilot trial was conducted to evaluate the usefulness of low-energy laser therapy in the control of pain associated with oral mucositis after stem cell transplantation or high-dose chemotherapy. Materials and Methods: Eleven patients with the diagnosis of chronic myelogenous leukemia (n = 4), non-Hodgkin's lymphoma (n = 3), acute myelocytic leukemia (n = 1), and other malignancies (n = 3) were submitted to high-dose chemotherapy for myeloablation. Seven patients received autologous stem cell transplantation, two from allogeneic sources, and two were given high-dose chemotherapy only. The oral cavity of all patients was examined by an oral medicine specialist during the pretransplant and prechemotherapy workup. The patients received irradiation with the mucolaser daily until post-transplant day 5. The entire oral mucosa was treated with a final energy density of 2 J/cm². Mucositis was clinically evaluated according to the WHO scale, and pain was measured by a visual analogue scale (VAS). Results: The laser treatment was well tolerated by the patients. Two patients had mucositis grade I-II, 8 patients had grade III-IV, and 1 patient had none. None of the patients had the maximal pain score. Six patients had grade 0-3 and 5 patients had grade 5-8 by VAS. The majority of patients associated the daily application of laser with prompt pain relief. Conclusion: The use of low-energy laser therapy may play a role in the control of pain associated with oral mucositis. In order to evaluate the efficacy of laser therapy in the prevention of mucositis after stem cell transplantation, a randomized controlled trial was initiated. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate in vitro, by scanning electron microscopy (SEM), the adhesion of blood components on root surfaces irradiated with Er:YAG (2.94 um) and GaAlAs Diode (808 nm) lasers and the effects on the morphology of irradiated root surfaces. Methods: One hundred samples of human teeth were obtained. They were previously planed and scaled with manual instruments and divided into five groups of 20 samples each: G1 (control group) - absence of treatment; G2 - Er:YAG laser (7.6 J/cm[2]); G3 - Er:YAG laser (12.9 J/cm[2]); G4 - Diode laser (90 J/cm[2]) and G5 - Diode laser (108 J/cm[2]). After these treatments, 10 samples of each group received a blood tissue but the remaining 10 did not. After laboratory treatments, the samples were obtained by SEM, the photomicrographs were analysed by the score of adhesion of blood components and the results were statistically analysed (Kruskall-Wallis and Mann-Whitney test). Results: In relation to the adhesion of blood components, the study showed no significant differences between the control group and the groups treated with Er:YAG laser ( p = 0.9633 and 0.6229). Diode laser radiation was less effective than control group and Er:YAG laser radiation ( p < 0.01). Conclusions: None of the proposed treatments increased the adhesion of blood components in a significant way when compared to the control group. Although the Er:YAG laser did not interfere in the adhesion of blood components, it caused more changes on the root surface, whereas the Diode laser inhibited the adhesion. [ABSTRACT FROM AUTHOR]

Background: The aim of the present study was to compare the effects of Er:YAG and diode laser treatments of the root surface on intrapulpal temperature after scaling and root planing with hand instruments. Methods: Fifteen extracted single-rooted teeth were scaled and root planed with hand instruments. The teeth were divided into 3 groups of 5 each and irradiated on their buccal and lingual surfaces: group A: Er:YAG laser. 2.94 µm/100 mJ/10 Hz/ 30 seconds; group B: diode laser, 810 nm/1.4 W/0.05 ms/30 seconds; group C: diode laser, 810 nm/1.4 W/0.05 ms/30 seconds. The temperature was monitored by means of a type T thermocouple (copper-constantan) positioned in the pulp chamber to assess pulpal temperature during and before irradiation. Afterwards, the specimens were longitudinally sectioned, and the buccal and lingual surfaces of each root were analyzed by Results; In the Er:YAQ laser group, the thermal analysis revealed an average temperature of -2.2 ± 1.5°C, while in the diode laser groups, temperatures were 1.6 ± 0.8°C at 1.0 W and 3.3 ± 1.0°C at 1.4 W. Electronic micrographs revealed that there were no significant morphological changes, such as charring, melting, or fusion, in any group, although the specimens were found to be more irregular in the Er:YAG laser group. Conclusions; The application of Er:YAG and diode lasers at the utilized parameters did not induce high pulpal temperatures. Root surface irregularities were more pronounced after irradiation with an Er:YAG laser than with a diode laser. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate in vitro, by scanning electron microscopy (SEM), the adhesion of blood components on root surfaces irradiated with Er:YAG (2.94 microm) and GaAlAs Diode (808 nm) lasers and the effects on the morphology of irradiated root surfaces., Methods: One hundred samples of human teeth were obtained. They were previously planed and scaled with manual instruments and divided into five groups of 20 samples each: G1 (control group) - absence of treatment; G2--Er:YAG laser (7.6 J/cm2); G3--Er:YAG laser (12.9 J/cm2); G4--Diode laser (90 J/cm2) and G5--Diode laser (108 J/cm2). After these treatments, 10 samples of each group received a blood tissue but the remaining 10 did not. After laboratory treatments, the samples were obtained by SEM, the photomicrographs were analysed by the score of adhesion of blood components and the results were statistically analysed (Kruskall-Wallis and Mann-Whitney test)., Results: In relation to the adhesion of blood components, the study showed no significant differences between the control group and the groups treated with Er:YAG laser (p = 0.9633 and 0.6229). Diode laser radiation was less effective than control group and Er:YAG laser radiation (p < 0.01)., Conclusions: None of the proposed treatments increased the adhesion of blood components in a significant way when compared to the control group. Although the Er:YAG laser did not interfere in the adhesion of blood components, it caused more changes on the root surface, whereas the Diode laser inhibited the adhesion.

The aim of this investigation was to evaluate the cleaning effect of CO(2) on surface topography and composition of failed dental implant surfaces. Ten failed dental implants were retrieved from nine patients (mean age, 46.33 +/- 5.81 years) as a result of early or late failure. The implants were divided into two parts: one side of the implant was irradiated with a CO(2) laser (test side), while the other side did not receive irradiation (control side). The CO(2) laser was operated at 1.2 W in a continuous wave for 40 seconds (40 J energy). The handpiece of the CO(2) laser was kept at a distance of 30 mm from the implant surface, resulting in a spot area of 0.031415 cm (38.20 W/cm; 1559 J/cm) in scanning mode (cervical-apical). One unused dental implant was used as a negative control for both groups. All implant surfaces were examined by scanning electron microscopy (SEM) and energy-dispersive spectrometer x-ray (EDS) for element analysis. SEM showed that the surface of the test sides consisted of different degrees of organic residues, appearing mainly as dark stains similar to those observed on the control sides. None of the test surfaces presented alterations such as crater-like alterations, lava-like layers, or melting compared with the nonirradiated surfaces. Foreign elements such as carbon, oxygen, sodium, calcium, and aluminum were detected on both sides. These results suggest that CO(2) laser irradiation does not modify the implant surface, although the cleaning effect was not satisfactory.

The purpose of this study was to morphologically evaluate, by means of scanning electron microscopy, the effects of Er:YAG laser on the treatment of root surfaces submitted to scaling and root planing with conventional periodontal instruments. Eighteen root surfaces (n = 18), which had been previously scaled and planed, were assigned to 3 groups (n = 6). The control Group (G1) received no further treatment; Group 2 (G2) was irradiated with Er:YAG laser (2.94 mum), with 47 mJ/10 Hz, in a focused mode with air/water spray during 15 s and with 0.57 J/cm of fluency per pulse; Group 3 (G 3) was irradiated with Er:YAG laser (2.94 mum), with 83 mJ/10 Hz, in a focused mode with air/water spray during 15 s and with 1.03 J/cm2 of fluency per pulse. We concluded that the parameters adopted for Group 3 removed the smear layer from the root surface, exposing the dentinal tubules. Although no fissures, cracks or carbonized areas were observed, an irregular surface was produced by Er:YAG laser irradiation. Thus, the biocompatibility of the irradiated root surface, within the periodontal healing process, must be assessed.