Laser therapy最新文献

Background and aims: Dentin hypersensitivity is a frequent oral condition among patients suffering from gingival recession. Recent studies have suggested that photobiomodulation has the potential to reduce inflammation and relieve pain. The present study aims to assess the effectiveness of a new design of photobiomodulation toothbrush with specific irradiation parameters as a homecare device in treating dentin hypersensitivity and to compare its therapeutic effect with that of fluoride varnish.

Materials and methods: Thirty patients with gingival recession and dentin hypersensitivity were selected and randomly assigned to three groups of equal size: fluoride varnish, photobiomodulation, and the combination. Dentin pain and hypersensitivity were measured using visual analog scale (VAS) by two distinct tests: the contact test with a periodontal probe and the air blast test on the areas of gingival recession and denuded root; once at baseline and again one month after the initial application of treatments. Laser irradiation was carried out at the wavelength of 660 nm in CW with an output power of 40 mW for 30 seconds per spot (1.2 J per spot, 6 J/cm² energy density, and 200 mW/cm² power density), perpendicularly to denuded root surfaces in non-contact mode.

Results: A significant reduction in dentin pain and hypersensitivity was observed in all three groups. However, the reduction was significantly greater in the combination group.

Conclusion: At-home treatment of dentin hypersensitivity with photobiomodulation toothbrush is a convenient, safe, and effective method for the management of dentin hypersensitivity.

Background and aims: Dental caries is a global concern and different materials and methods were proposed for its prevention.The aim of this study was evaluation of the effect of different demineralizing agents with and without diode laser radiation on the microhardness of primary molars enamel.

Materials and methods: 48 primary molar teeth were used in this study. The enamel blocks were prepared. Primary microhardness values were also measured. All samples were demineralized, then demineralization was approved by a DIAGNOdent pen. The remineralization was done into the buccal and lingual surfaces of the samples as follows:Group 1: CPP-ACP, Group 2: CPP-ACPF, Group 3: MI varnish, Group 4: NaF varnish. The lingual surfaces received diode laser irradiation. Finally, a secondary microhardness test was performed on all samples. Statistical analyses were done and a P-value less than 0.05 was considered to be statistically significant.

Results: A comparison between the primary and the secondary microhardness values showed significant differences (P = 0.003). The highest secondary microhardness values belonged to the MI varnish +laser group.

Conclusion: Application of the agents, containing the combination of Ca, P, and F, was significantly better than others in increasing the microhardness of the enamel. Although the application of diode laser increased the hardness of the enamel.

Background and aims: Several studies highlighted how the ameloblasts, secretory cells responsible of the tooth enamel formation, are highly sensitive to changes in their environment. Due to enamel maturation, their dysfunctions during a limited period of tooth development may lead to permanent morphological consequences, namely Developmental Enamel Defects (DED). The aim of this study was to show the advantages of Er:YAG laser for DED treatment.

Subjects and methods: The case report presented describes the treatment, by Er:YAG laser, of some DED lesions present in the upper incisors of a young patient. The settings used were: 1W power, 100mJ energy, 10 Hz frequency corresponding to a Fluence of 0.318 J/cm² per pulse or 3, 18 J/cm².

Results: The patient, even in absence of local anesthesia, did not feel any pain or discomfort during and after intervention. Follow-up at 2, 6 and 12 months did not show any problems in an aesthetic point of view as well as regarding hypersensitivity.

Conclusions: The use of Er:YAG laser for the treatment of developmental enamel defects in frontal teeth is a safe, painless and minimally invasive; moreover, it is able to assure a good aesthetic result.

The aim of this study was to test the application in vitro of different laser wavelengths at a low fluence in combination or not with proper photosensitizing dyes on Candida albicans biofilm with or without a synthetic killer decapeptide (KP). Candida albicans SC5314 was grown on Sabouraud dextrose agar plates at 37°C for 24 h. Cells were suspended in RPMI 1640 buffered with MOPS and cultured directly on the flat bottom of 96-wells plates. The previously described killer decapeptide KP was used in this study. Three different combinations of wavelengths and dyes were applied, laser irradiation has been performed at a fluence of 10 J/cm². The effect on C. albicans biofilm was evaluated by the XTT assay. Microscopic observations were realized by fluorescence optic microscopy with calcofluor white and propidium iodide. Compared with control, no inhibition of C. albicans biofilm viability was obtained with application of red, blue and green lasers alone or with any combination of red diode laser, toluidine blue and KP. The combined application of blue diode laser with curcumin and/or KP showed always a very significant inhibition, as curcumin alone and the combination of curcumin and KP did, while combination of blue diode laser and KP gave a less significant inhibition, the same obtained with KP alone. The combined application of green diode laser with erythrosine and/or KP showed always a very significant inhibition, as the combination of erythrosine and KP did, but no difference was observed with respect to the treatment with erythrosine alone. Again, combination of green diode laser and KP gave a significant inhibition, although paradoxically lower than the one obtained with KP alone. Treatment with KP alone, while reducing biofilm viability did not cause C. albicans death in the adopted experimental conditions. On the contrary, combined treatment with blue laser, curcumin and KP, as well as green laser, erythrosine and KP led to death most C. albicans cells. The combination of laser light at a fluence of 10 J/cm² and the appropriate photosensitizing agent, together with the use of KP, proved to exert differential effects on C. albicans biofilm.

Background and aims: Nowadays, studies show the effective laser irradiation role on the adhesion of bonding agents to the dentin. Therefore, the present study was set to find an appropriate protocol for the use of Nd:YAG, Er:YAG, and Diode lasers during the application of two steps self-etch adhesives in direct dental restorations in order to achieve higher microtensile strength.

Materials and methods: A total number of 100 extracted healthy teeth were selected. After removing occlusal enamel and exposing dentin, samples randomly divided into ten groups: Group Control (C), two steps self-etch adhesives was applied in accordance with the manufacturer instructions, without using laser systems; Groups Er-YAG, laser (2940 nm, 10 Hz, 0.4w, 40 mJ) irradiated Before applying Primer (Er-BP subgroup), After applying Primer (Er-AP subgroup), After applying Bonding (Er-AB subgroup); Groups Nd-YAG, laser (1064 nm, 10 Hz, 1.2w, 40 mJ) irradiated Before applying Primer (Nd-BP subgroup), After applying Primer (Nd-AP subgroup), After applying Bonding (Nd-AB subgroup); Groups Diode, laser (940 nm, 10 Hz, 0.7w, 70 mJ) irradiated Before applying Primer (D-BP subgroup), After applying Primer (D-AP subgroup), After applying Bonding (D-AB subgroup). After intervention and composite build up, the samples were stored 24 hours in 37°C distilled water. The microtensile strength was measured using the universal testing machine. The data were analyzed by one-way ANOVA test and post hoc Tukey test. (p < 0.05).

Results: The Means and standard deviations of the groups were as follow: C = 30.09 ± 4.21, Er-BP = 18.83 ± 4.21, Er-AP = 14.43 ± 3.12, Er-AB = 19.67 ± 4.96, Nd-BP = 20.35 ± 5.55, Nd-AP = 39.85 ± 4.13, Nd-AB = 18.16 ± 3.36, D-BP = 26.74 ± 5.05, D-AP = 28.11 ± 5.12, D-AB = 37.28 ± 5.61. The mean microtensile strength achieved in groups: Nd-AP and D-AB were significantly higher than control group (p < 0.05). Groups D-BP and D-AP had no significant difference in comparison with control group while the remaining groups had significantly lower values (P < 0.05).

Conclusions: Nd:YAG laser irradiation after applying the primer, and diode laser irradiation after applying the bonding agent, both can improve the microtensile bond strength in two steps self-etch adhesive systems significantly.

Endoscopic Submucosal Dissection (ESD) has been increasingly accepted as a minimally invasive treatment for the patients with early gastrointestinal cancers. However, reliable ESD technique demands high maneuverability, and the success of the operation is dependent on each operator's skill. We have developed a novel laser endoscopic system for ESD to overcome such technique-related difficulties. Compared to conventional ESD using electrosurgical knives, an ESD method using the CO₂ laser offers the advantages of less risk of perforation and the prevention of extensive thermal damage, because the CO₂ laser is strongly absorbed by water. Furthermore, due to the non-contact technique associated with the CO₂ laser and adequate visualization of the treatment area, the laser system may provide every endoscopist with more precise and safer treatment.

Aim: The aim of this study was to evaluate and compare caries removal by Er,Cr:YSGG Laser and conventional method using Air-rotor handpiece in primary teeth.

Materials and methods: 25 children with at least two class I carious lesions on primary teeth with Diagnodent readings not differing more than ± 10 for both teeth were included in the study. All 50 teeth in the study received treatment by the same operator. Time taken for caries removal was recorded using a timer. Pain assessment was done using Wong Baker Modified Faces Pain Rating Scale and Visual Analog Scale before and after the procedure. After caries removal, caries detection dye was applied to the prepared cavity to check the efficacy of the procedure. In addition, after completion of treatment, each child was asked to indicate which method of caries removal, Er,Cr:YSGG Laser or Air-rotor handpiece, was more comfortable.

Results: The difference between the mean values for post-procedural Wong Baker Faces Pain Rating Scale scores and Visual Analog Scale scores in Group A and Group B were compared, which showed that children experienced less pain during the caries removal procedure with Er,Cr:YSGG Laser than with Air-rotor handpiece. Time taken for caries removal procedure was more in Group A than in Group B. It was seen that in both the groups caries detection dye was completely removed and both the procedures were equally efficacious for caries removal. Children indicated caries removal procedure with Laser to be more comfortable.

Conclusion: Within the parameters and limitations of the present study, it is suggested that Er,Cr:YSGG Laser seems to be an acceptable tool for caries removal in primary teeth. Children found caries removal with Er,Cr:YSGG Laser to be more comfortable even though time taken was more than the conventional method using Air-rotor handpiece.