scholarly journals An In Vitro Comparison of the Bond Strength of Composite to Superficial and Deep Dentin, Treated With Er:YAG Laser Irradiation or Acid-Etching

2016 ◽  
Vol 7 (3) ◽  
pp. 167-171 ◽  
Author(s):  
Homayoon Alaghehmand ◽  
Fatemeh Nezhad Nasrollah ◽  
Hanieh Nokhbatolfoghahaei ◽  
Reza Fekrazad
2013 ◽  
Vol 83 (6) ◽  
pp. 973-980 ◽  
Author(s):  
Serkan Sağır ◽  
Aslıhan Usumez ◽  
Ebru Ademci ◽  
Serdar Usumez

ABSTRACT Objective: To compare the effect of laser irradiation at two different pulse settings and acid etching on the shear bond strength (SBS) of orthodontic brackets to enamel. Materials and Methods: Thirty-six premolars were allocated to three groups (n  =  12): (1) 37% phosphoric acid etching, (2) erbium-doped yttrium aluminum garnet (Er:YAG) laser etching with medium-short pulse mode (MSP; 100 µs, 120 mj, 10 Hz, 1.2 W), and (3) Er:YAG laser etching with quantum-square pulse mode (QSP; 120 mj, 10 Hz, 1.2 W). Metallic brackets were bonded with Transbond XT. After photopolymerization, the samples were subjected to 5000 thermal cycles and debonded with a universal testing machine, and the SBS values were recorded. Surface morphology was evaluated with profilometric examination, scanning electron microscopy, and atomic force microscopy. The adhesive remnant index (ARI) was evaluated to assess the remaining adhesive. Results: The results of SBS testing were analyzed by one-way analysis of variance and Tukey honestly significant diffference tests. The mean SBS values of QSP and MSP laser groups were 11.80 ± 2.7 MPa and 10.10 ± 4.5 MPa, respectively, and the QSP group demonstrated significantly higher SBS (P < .01) than that of the acid-etched group (6.6 ± 2.4 MPa). No significant difference was observed between the SBS values of the two laser groups (P < .05). The difference between the ARI scores of the laser groups and the acid-etched group was statistically significant (P < .05). Conclusion: Laser etching at MSP and QSP modes present successful alternatives to acid etching; however, long-term clinical studies are required to verify clinical success.


Author(s):  
Katharina Kuhn ◽  
Carmen U. Schmid ◽  
Ralph G. Luthardt ◽  
Heike Rudolph ◽  
Rolf Diebolder

AbstractInadvertent Er:YAG laser irradiation occurs in dentistry and may harm restorative materials in teeth. The aim of this in vitro study was to quantify Er:YAG laser-induced damage to a nanohybrid composite in simulated clinical scenarios for inadvertent direct and indirect (reflection) laser irradiation. The simulation was performed by varying the output energy (OE;direct˃indirect) reaching the specimen and the operating distance (OD;direct˂indirect). Composite specimens were irradiated by an Er:YAG laser. The ablation threshold was determined and clinically relevant parameters were applied (n = 6 for each OE/OD combination) for direct (OE: 570 mJ/OD: 10 mm, OE: 190 mJ/OD: 10 mm) and indirect irradiation (OE: 466 mJ/OD: 15 mm, OE: 57 mJ/OD: 15 mm, OE: 155 mJ/OD: 15 mm, OE: 19 mJ/OD: 15 mm). The extent of damage in the form of craters was evaluated using a laser scanning microscope (LSM) and a conventional light microscope (LM). The ablation threshold was determined to be 2.6 J/cm2. The crater diameter showed the highest value (LM: 1075 ± 18 µm/LSM: 1082 ± 17 µm) for indirect irradiation (reflectant:dental mirror) (OE: 466 mJ/OD: 15 mm). The crater depth showed the highest and comparable value for direct (OE: 570 mJ/OD: 10 mm; LSM: 89 ± 2 µm) and indirect irradiation (OE: 466 mJ/OD: 15 mm; LSM: 90 ± 4 µm). For each OD, the crater diameter, depth, and volume increased with higher laser fluence. However, the OD—and thus the laser spot diameter—also had an enlarging effect. Thus, indirect irradiation (reflectant:dental mirror) with only 47% of the laser fluence of direct irradiation led to a larger diameter and a comparable depth. The three-dimensional extent of the crater was large enough to cause roughening, which may lead to plaque accumulation and encourage caries, gingivitis, and periodontitis under clinical conditions. Clinicians should be aware that reflected irradiation can still create such craters.


2019 ◽  
Vol 10 (4) ◽  
pp. 304-309
Author(s):  
Larissa Costa Santos ◽  
Ravana Angelini Sfalcin ◽  
Eugenio José Garcia ◽  
Fátima Antônia Aparecida Zanin ◽  
Aldo Brugnera Junior ◽  
...  

Introduction: Microleakage has been reported to cause dentin hypersensitivity because of the passage of bacteria and their products through the restoration-tooth interface and is one of the main reasons for replacement of restorations. CO2 laser can be used for treatment of dentin hypersensitivity. Thus, this study aimed to evaluate in vitro the microleakage in composite restorations following surface pretreatment with acid etching and CO2 laser. Methods: Twelve human caries-free primary molars were selected. Class II cavities were prepared on occlusal mesial and occlusal distal surfaces. Specimens were randomly divided into four groups (n=6): Group 1 (G1) – 37% phosphoric acid gel etching + Beautiful-Bulk Restorative – Giomer (Shofu Inc); Group 2 (G2) – 37% phosphoric acid gel etching + SDR Bulk-Fill Flow (Dentsply); Group 3 (G3) – CO2 laser irradiation + Beautiful-Bulk Restorative – Giomer (Shofu Inc); Group 4 (G4) – CO2 laser irradiation + SDR Bulk-Fill Flow (Dentsply). Surfaces were restored with bonding agent (Natural Bond DE, DFL). Specimens were cut longitudinally and immersed in 0.5% methylene blue solution for 4 hours. Microleakage scores were assessed under a magnifying glass at x3,5 and qualitatively analyzed by scanning electron microscope (SEM). Data were analyzed using nonparametric Wilcoxon test (P < 0.05). Results: Scores prevailed between 0 and 2, however, no statistically significant difference was found among the groups (P= 0.05). Conclusion: It could be concluded that all composite resins bulk fill did not show significant difference among them regarding microleakage using either CO2 laser or 37% phosphoric acid etching.


2020 ◽  
Vol 10 (10) ◽  
pp. 3431
Author(s):  
Shih-Hao Chang ◽  
Hsiang-I Mei ◽  
Chun-Li Lin

This study established an in vitro model mimicking clinical peri-implant intra-bony defects. We investigated the effect of access limitation and the bactericidal effectiveness of erbium-doped yttrium, aluminum and garnet (Er:YAG) laser irradiation in shallow and deep peri-implant defects at different tooth positions. Reverse engineering, computer-aided design (CAD), and 3D-printing techniques were integrated to establish physical peri-implant intra-bony defect models at mandibular central incisor, first premolar, and first molar positions with shallow (2 mm depth) or deep (6 mm depth) defects and with 1.5 mm and 1.8 mm widths at the bottom and crestal portions of the alveolar process, respectively. Three-dimensional printed suites at the corresponding implant sites replaced experimental implant specimens for the investigation of bacterial adhesion in individuals. Dental implants with diameters of 3, 4 and 5 mm were utilized at the mandibular incisor, premolar, and molar positions, respectively. Bacterial adhesion of Gram (–) Escherichia coli on the exposed implant surfaces prior to sterilization was assessed. Sterilization with shallow and deep intra-bony defects was investigated by measuring the reduction of residual viable bacteria on implants after 60 s of irradiation with an Er:YAG laser. The adhesion rate of Gram (–) Escherichia coli on the investigated implant surfaces ranged from 1% to 3% (1.76 ± 1.25%, 2.19   ±   0.75% and 2.66   ±   1.26% for 3, 4, and 5 mm implants, respectively). With shallow peri-implant bony defects, the Er:YAG laser sterilization rates were 99.6 ± 0.5%, 99.3   ±   0.41% and 93.8 ± 7.65% at mandibular incisor, premolar, and molar positions, respectively. Similarly, sterilization rates in deep peri-implant defects were 99 ± 1.35%, 99.1 ± 0.98% and 97.14 ± 2.57%, respectively. A 3D-printed model with replaceable implant specimens mimicking human peri-implant intra-bony defects was established and tested in vitro. This investigation demonstrated effective sterilization using Er:YAG laser irradiation in both shallow and deep peri-implant intra-bony defects at different positions and diameters of dental implants.


2009 ◽  
Vol 34 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Senem Selvi Kuvvetli ◽  
Nuket Sandalli ◽  
Nursen Topcuoglu ◽  
Guven Kulekci

Objective: In vitro comparison of the antibacterial efficacy of Diode and Er:YAG laser irradiation with that of NaOCl irrigation in contaminated primary molar root canals. Study Design: 96 root canals prepared from 32 extracted primary molar teeth were mechanically enlarged and the teeth were randomly divided into 4 subgroups. The roots were inoculated with an overnight culture of Enterococcus faecalis in tryptic soy broth for 24 hours. The root canals irradiated with diode and Er:YAG laser and irrigated with NaOCl(5.25%) were experimental groups and untreated canals served as positive control group. Bacterial growth was analysed by counting viable E.faecalis on tryptic soy agar plates. Results: The number of bacteria was significantly reduced in experimental groups in comparison with the control group. Diode laser was determined to be more effective in reducing the number of bacteria when compared to Er:YAG laser. NaOCl irrigation was found significantly most effective. Conclusions: Diode laser irradiation and 5.25 % NaOCl application provided a significant antibacterial effect in vitro, in contaminated primary molar root canals.


Sign in / Sign up

Export Citation Format

Share Document