Background and Aims: Recently, the addition of nanoparticles into the restorative materials and tooth preparation by laser for improving the bond strength have been concidered by researchers. The aim ...of this study was to investigate the shear bond strength of the bioactive glass ionomer containing titanium particles and a conventional glass ionomer with two surface treatments by Er-YAG laser and conventional methods. Materials and Methods: In this in-vitro study, 64 sound extracted premolars were collected. For conventional method, the specimens were prepared in such a way that dentin surfaces with a depth of 0.5 millimeter created at distance of 2 mm from the joint of CEJ at the root or crown. In the laser group, after preparing the teeth, the surface area was prepared by Er-YAG laser. Then, in the middle part of the buccal surface, a cylindrical mold with dimensions of 3.5 mm in diameter and 4 mm in height was placed and for each group was filled with its own glass ionomers. The specimens were divided into 8 groups by simple random sampling (n=8): A (laser, conventional glass ionomer, coronal dentin)/ B (laser, glass ionomer containing titanium nanoparticle, coronal dentin)/C (conventional, conventional glass ionomer, coronal dentin)/ D (conventional, glass ionomer containing titanium nanoparticle, coronal dentin)/ E (laser, conventional glass ionomer, root dentin)/ F (laser, glass ionomer containing titanium nanoparticle, root dentin)/ G (conventional, conventional glass ionomer, root dentin)/ H (conventional, glass ionomer containing titanium nanoparticle, coronal dentin). Finally, the shear bong strength by a universal testing machine was measured at a cross-head speed of 1 mm/min. For data analysis, Two-way ANOVA test was used to evaluate the effect of each variable and their interaction on the shear bond strength and Tukey test was used to compare the two groups. Results: There was significant difference only between groups B with C (P=0.002), E (P=0.007), G (P=0.001) and H (P=0.01). The highest bond strength was found for group B (laser, glass ionomer containing titanium nanoparticle, coronal dentin) and the lowest bond strength for group G (conventional, conventional glass ionomer, root dentin). Conclusion: All three factors of Er-YAG laser, glass ionomer containing titanium nanoparticle and coronal dentin had a positive effect on the improvement of the bond strength.
Purpose: The erbium: YAG (Er: YAG) laser is used for decontaminating implant surfaces in the treatment of peri-implantitis. In this study, we quantified lipopolysaccharides (LPS) before and after ...decontaminating the contaminated layer on the implant surface, using an Er: YAG laser. In addition, we report that the peri-implantitis of the patient improved, based on the results of clinical evaluation, bacteriological examination, and cone-beam computed tomography (CBCT). Patient: A 68-year-old woman visited our hospital with the chief complaint of drainage from an implant. Her implant superstructures had been installed eight years ago, and she had no systemic disease except periodontal disease. X-ray examination revealed high resorption of the alveolar bone around the implant, and CBCT images revealed bone resorption; the resorbed bones were half the length of the implant. In addition, bacterial examination of the peri-implant pocket revealed Tannerella forsythensis, Treponema denticola, and Fusobacterium nucleatum. Although the implant showed no mobility, the probing periodontal pocket depth (PPD) of the labial center was 14 mm, and the distopalatal PPD was 10 mm. After the initial periodontal therapy, the PPD was 10-13 mm, and it bled on probing. Therefore, a surgical procedure was performed to treat the peri-implantitis. After administration of anesthesia, a full-thickness flap was raised, and a vertical bone defect with three walls on the apical side and one wall on the crown side was observed. The inflammatory tissue around the bone defect and the implant surface were decontaminated using an Er: YAG laser with water spray. LPS on the implant surface were sampled twice before and after decontamination and quantified using the Limulus amebocyte lysate method. The average of all the values was used as the LPS value, which decreased from 10.3755 to 0.0015 EU/ml. Bio-Gide was applied after insertion of Bio-Oss, and the flap was repositioned and sutured. Results: The PPD of the implant site stabilized at 2-3 mm 10 months after the procedure. A comparison of periodontal disease-related bacterial tests before and 12 months after surgery revealed that the numbers of T. forsythensis, T. denticola, and F. nucleatum decreased after surgery. Newly formed bone was observed in the intrabony defect from the CBCT images. Conclusion: In this case, the contaminated layer on the implant surface was decontaminated by an Er: YAG laser used for the treatment of peri-implantitis, along with reduction of LPS on the implant surface, facilitating long-term bone regeneration.
Objectives: The purpose of this study was to determine if Er: YAG laser etching improves the shear bond strength (SBS) of Biodentin™ and GC Fuji IX® to dentine. Materials and Methods: Forty human ...dentine specimens were standardized and embedded in stone. The specimens were randomized into four groups (n = 10). Twenty samples were treated with the Er: YAG laser radiation and 10 of these restored with GC Fuji IX® and 10 with Biodentine™. The remaining 20 specimens acted as controls (no laser treatment); 10 were restored with GC Fuji IX® and 10 with Biodentin™. All samples were then stored in an incubator at 37.5°C and 100% humidity for 7 days. The SBS was determined using a Zwick universal testing machine. A two-way analysis of variance test was used to evaluate the statistical difference in SBS between the groups. An independent sample t-test was used to determine the statistical significance of differences between control and lased groups within the same material. Results: A highly statistically significant difference in SBS was found with the laser treatment (P = 0.0001) and material (i.e., Biodentin™ or Fuji IX® (P = 0.0001). The GC Fuji IX® group recorded the highest mean SBS required to dislodge the material from the laser-treated dentine surface (1.77 ± 0.22 Mega-Pascal MPa). The mean SBS of Biodentin™ to dentine following the laser radiation (1.12 ± 0.16 MPa) was significantly greater compared to the nonlased dentine (0.53 ± 0.09). Pearson Chi-square test indicated a nonsignificant relation between shear strength and mode of failure (P = 0.467). Conclusion: Laser etching of the dentine surfaces yielded a significant increase in the bond strength for both GC Fuji IX® and Biodentin™. The SBS of Biodentin™ to dentine is greater than with conventional glass ionomer (Fuji IX®).
Stapes surgery is performed using both conventional techniques and a variety of laser systems. The Er-Yag laser is a type of pulsation laser deemed by many to be the safest for ear surgery. The aim ...of this study was to assess the long-term effects of using the Er-Yag laser in stapes surgery and its impact on inner ear function. The study was conducted on 95 ears (48 right and 47 left) that had undergone Er-Yag laser-assisted stapedotomy. The follow-up time was at least 3 years. Pure tone audiometry was performed on all patients. The frequency ranged from 125 to 8,000 Hz. Air conduction and bone conduction were both assessed. Moreover, all patients had their stapedius reflex assessed and were given a Rinne test. The results were evaluated according to the Committee on Hearing and Equilibrium guidelines and then statistically analyzed using the Wilcoxon sequence pair test with a
p
value of <0.05. A decrease in the hearing threshold of 0.5, 1, and 3 kHz, for both bone and air conduction was observed for all patients (
p
< 0.0001). The Wilcoxon sequence pair test revealed a statistically significant correlation between the pre- and postoperative treatment mean air-bone gap values (
p
< 0.0001). No facial nerve paralysis was observed. No Er-Yag laser side effects were observed on inner ear function. The patients also had lower hearing thresholds. These observations demonstrate the usefulness of Er-Yag lasers in stapes surgery.
Enamel demineralisation is an initial step of the serious dental problem including dental caries, white spot lesions and dental erosion.
Compare the effect of Er, Cr: YSGG (λ = 2780 nm) and ...nanosecond Nd: YAG (λ = 1064 nm) laser on enamel acid resistance.
Thirty non-carious human premolars, extracted for orthodontic reasons, were used. The experimental groups (n = 10 each group) were: Group I, untreated (control); Group II, Er, Cr: YSGG laser irradiation (0.75 W, 20 Hz, 140 μs, 10 s); Group III, nanosecond pulsed Nd: YAG laser irradiation (0.8 W, 10 Hz, 7 ns, 10 s). Scanning electron microscope and Energy Dispersive X-ray Spectroscopy (EDX) were used to assess acquired enamel resistance to PH cycling.
After subjecting the three experimental groups to PH cycling, scanning electron microscopic examination revealed irregular porous dissoluted enamel surface in group I. However, groups II and III demonstrated partially dissoluted enamel surface. EDX analysis demonstrated the lowest mean percentage decrease in calcium and phosphorus content in group II followed by group III, then the highest mean percentage decrease was observed in untreated group I. One-way ANOVA revealed significant differences (p < 0.0001) between the tested groups.
Both Er, Cr: YSSG and nanosecond Nd: YAG laser irradiation were able to improve the acid resistance of enamel. However, enamel surface treated with Er, Cr: YSSG laser showed the lowest mean percentage decrease of calcium and phosphorus (highest acid resistance).
Melasma is one of the most common skin pigmentation disorders, which mostly affects the facial skin and has a considerable psychological impact on the patients. Melasma management has been one of the ...controversial issues in dermatology. We aimed to compare the combined treatment of the Er: YAG (erbium: yttrium-aluminum-garnet) laser plus hydroquinone (HQ) 4% with HQ 4% alone in the treatment of melasma.
Twenty-nine patients were treated with the combined Er: YAG laser and HQ 4% on one side of the face with HQ 4% alone on the other side. Three sessions of the laser rat 4-week intervals. The outcome was calculated using the Melasma Area Severity Index (MASI).
The side that received the combined treatment (laser + HQ 4%) showed a statistically significant reduction in MASI compared to the side treated with HQ 4% alone.
Our study suggests the superiority of the combination of the Er: YAG laser and HQ 4% in the treatment of melasma compared to HQ 4% alone.
Rotundo R, Nieri M, Cairo F, Franceschi D, Mervelt J, Bonaccini D, Esposito M, Pini‐Prato G. Lack of adjunctive benefit of Er:YAG laser in non‐surgical periodontal treatment: a randomized split‐mouth ...clinical trial. J Clin Periodontol 2010; 37: 526–533. doi: 10.1111/j.1600‐051X.2010.01560.x.
Aim: This split‐mouth, randomized, clinical trial aimed to evaluate the efficacy of erbium‐doped:yttrium–aluminium–garnet (Er:YAG) laser application in non‐surgical periodontal treatment.
Materials and Methods: A total of 27 patients underwent four modalities of non‐surgical therapy: supragingival debridement; scaling and root planing (SRP)+Er:YAG laser; Er:YAG laser; and SRP. Each strategy was randomly assigned and performed in one of the four quadrants. Clinical outcomes were evaluated at 3 and 6 months. Subjective benefits of patients have been evaluated by means of questionnaires.
Results: Six months after therapy, Er:YAG laser showed no statistical difference in clinical attachment gain with respect to supragingival scaling 0.15 mm (95% CI −0.16; 0.46), while SRP showed a greater attachment gain than the supragingival scaling 0.37 mm (95% CI 0.05; 0.68). No difference resulted between Er:YAG laser+SRP and SRP alone 0.05 mm (95% CI −0.25; 0.36).
Conclusions: The adjunctive use of Er:YAG laser to conventional SRP did not reveal a more effective result than SRP alone. Furthermore, the sites treated with Er:YAG laser showed similar results of the sites treated with supragingival scaling.
Purpose: The Er: YAG laser shows excellent performance in hard tissue cutting, and is used in clinical dentistry. However, the cutting efficiency is far inferior to high-speed rotation devices, ...resulting in increased treatment time. Our study constructed a prototype tip with a spray-type irrigation system to improve the cutting efficiency. The prototype tip has become commercially available, and is marketed under the name “CS600F”. The present study investigated the cutting volume of human dentin, as well as the tip head wear, wear rate, and output using the CS600F. Methods: Sound human molars were used as samples. A smooth dentin surface was exposed by trimming the tooth with a model trimmer, and then polishing the surface with waterproof abrasive paper up to 2000 grit. The laser was moved evenly across a 4×4 mm area on the sample surface by moving the stage 0.5 mm/s, with 10 cycles of laser irradiation. Irradiation distances were set at 0.5, 1.0, and 2.0 mm. Samples irradiated with the C600F were defined as the control group, and those irradiated with the CS600F were defined as the atomized spray group. Each sample and tip head was observed under a microscope to measure the dentin cutting volume and tip head wear volume, and the tip head wear rate was calculated (n=3). Output power from the tip head after irradiation was measured and compared with the output power from the tip head set before irradiation. Results: Dentin cutting volume and tip head wear rate were significantly higher in the atomized spray group compared with the control group. However, tip head wear and output showed no significant differences between the two groups (p≧0.05). Conclusion: The use of atomized spray irrigation may improve the dentin cutting volume without any change in the extent of tip wear during dentin cutting. There was no change in the tip head output after 10 cycles of irradiation in either the conventional or atomized spray irrigation systems.
PDF
