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Jiang L, Li XY, Lu ZC, Yang S, Chen R, Yu H. Er:YAG laser settings for debonding zirconia restorations: An in vitro study. J Mech Behav Biomed Mater 2024; 151:106331. [PMID: 38176195 DOI: 10.1016/j.jmbbm.2023.106331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 12/13/2023] [Accepted: 12/14/2023] [Indexed: 01/06/2024]
Abstract
This in vitro study aimed to determine the optimal frequency and energy settings for debonding zirconia restorations using an erbium-doped yttrium aluminum garnet (Er:YAG) laser. A total of 200 zirconia specimens (5 mm × 5 mm × 1.5 mm) were fabricated from two types of materials: (1) 3 mol% yttria oxide stabilized tetragonal zirconia polycrystalline (3Y-TZP) and (2) 5 mol% yttria oxide stabilized tetragonal zirconia polycrystalline (5Y-TZP). The zirconia specimens were bonded to dentin using resin cement (RelyX Ultimate, 3 M) and divided into 20 groups based on their laser treatments (n = 5). Er:YAG laser treatment was applied at various frequencies (10 Hz and 20 Hz) and energies (80 mJ, 100 mJ, 120 mJ, 140 mJ, 160 mJ, 180 mJ, 200 mJ, 220 mJ, 240 mJ, and 260 mJ). The time required to debond the specimens and the temperature changes that dentin underwent during the laser treatment were recorded. The surface morphologies of the debonded dentin and zirconia specimens were observed using scanning electron microscopy (SEM). Additional zirconia specimens were fabricated for 4-point flexural strength testing and surface roughness measurements. Statistical analyses were conducted using three-way analysis of variance (ANOVA) and Student-Newman-Keuls (SNK)-q tests (α = 0.05). The debonding time of each specimen varied between 4.8 and 160.4 s, with an average value of 59.2 s. The dentin temperature change for each specimen ranged from 2.3 to 3.6 °C, with an average value of 2.7 °C. The debonding time was significantly influenced by the zirconia material type and laser energy, but it was not affected by the laser frequency. Among the specimens, those made of 3Y-TZP needed significantly more time for debonding than 5Y-TZP. The optimal energies were 220 mJ for 3Y-TZP and 200 mJ for 5Y-TZP. The laser frequency, laser energy, and type of zirconia material had no effect on the dentin temperature change. Additionally, no surface alternations were observed on the dentin or zirconia materials after laser treatment. The surface roughness and flexural strength of the zirconia materials remained unchanged after laser treatment. In summary, Er:YAG laser treatment effectively and safely removes zirconia restorations without impacting their mechanical properties, with a safe temperature change of less than 5.6 °C. The optimum frequency and energy settings for debonding 3Y-TZP and 5Y-TZP restorations were found to be 10/20 Hz and 220 mJ and 10/20 Hz and 200 mJ, respectively.
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Affiliation(s)
- Lei Jiang
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China; Department of Prosthodontics & Research Center of Dental Esthetics and Biomechanics, Fujian Medical University, China
| | - Xue-Yu Li
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China; Department of Prosthodontics & Research Center of Dental Esthetics and Biomechanics, Fujian Medical University, China
| | - Zhi-Cen Lu
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China; Department of Prosthodontics & Research Center of Dental Esthetics and Biomechanics, Fujian Medical University, China
| | - Song Yang
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China; Department of Prosthodontics & Research Center of Dental Esthetics and Biomechanics, Fujian Medical University, China
| | - Run Chen
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China; Department of Prosthodontics & Research Center of Dental Esthetics and Biomechanics, Fujian Medical University, China.
| | - Hao Yu
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China; Department of Prosthodontics & Research Center of Dental Esthetics and Biomechanics, Fujian Medical University, China; Clinic of Conservative and Preventive Dentistry, Center for Dental Medicine, University of Zurich, Switzerland; Department of Applied Prosthodontics Graduate School of Biomedical Sciences, Nagasaki University, Japan
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Liu C, Chen R, Han C, Pi X, Chang S, Jiang H, Long X, Du M. Water jet as a novel technique for enamel drilling ex vivo. PLoS One 2021; 16:e0254787. [PMID: 34297732 PMCID: PMC8301641 DOI: 10.1371/journal.pone.0254787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 07/02/2021] [Indexed: 11/19/2022] Open
Abstract
To investigate the usage of a water jet for enamel drilling ex vivo, 210 individual extracted molars without lesions or fillings were collected. Then, the specimens were drilled by a water jet or a high-speed dental drill. The cavities of 50 teeth were reconstructed digitally by micro-computed tomography (micro-CT) to measure the height and width. The cavities of 10 teeth were longitudinally incised and their surfaces were observed by scanning electronic microscopy (SEM). After the cavities were filled, 50 fillings were vertically incised. The bonding interface between tooth and filling was observed by SEM. 50 teeth with fillings were stained in 0.1% rhodamine B solution, and then the dye penetration between tooth and filling was observed under the stereomicroscope and confocal laser scanning microscopy (CLSM). The bonding strength between enamel and filling of 50 teeth was simulated and predicted with finite element analysis (FEA). At 140-150 MPa and for 2-3 s, cavities were made with a depth of approximately 764 μm in each tooth. SEM showed the cavity surface in the water jet group had a more irregular concave and convex structure than that in the high-speed dental drill group. There was a trend that the microleakage and bonding width was smaller in the water jet group than in the high-speed dental drill group. FEA indicated that the stress on the resin surface was greater than on the enamel surface in the water jet group. Compared with the tooth drilled by a high-speed dental drill, the tooth drilled by a water jet gained better retention of the filling material and suffered less bonding strength on the enamel surface. Water jet drilling is effective for enamel drilling.
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Affiliation(s)
- Chang Liu
- School & Hospital of Stomatology, The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, Wuhan University, Wuhan, Peoples R China
| | - Rourong Chen
- School & Hospital of Stomatology, The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, Wuhan University, Wuhan, Peoples R China
| | - ChengZao Han
- Wuhan Univ, Sch Power & Mech Engn, State Key Lab Water Resources & Hydropower Engn S, Wuhan, Peoples R China
| | - Xiaoqin Pi
- School & Hospital of Stomatology, The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, Wuhan University, Wuhan, Peoples R China
| | - Shuli Chang
- School & Hospital of Stomatology, The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, Wuhan University, Wuhan, Peoples R China
| | - Han Jiang
- School & Hospital of Stomatology, The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, Wuhan University, Wuhan, Peoples R China
| | - Xinping Long
- Wuhan Univ, Sch Power & Mech Engn, State Key Lab Water Resources & Hydropower Engn S, Wuhan, Peoples R China
| | - Minquan Du
- School & Hospital of Stomatology, The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, Wuhan University, Wuhan, Peoples R China
- * E-mail:
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A review of heat transfer in human tooth—Experimental characterization and mathematical modeling. Dent Mater 2010; 26:501-13. [DOI: 10.1016/j.dental.2010.02.009] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 01/04/2010] [Accepted: 02/23/2010] [Indexed: 12/28/2022]
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Firoozmand L, Faria R, Araujo MA, di Nicoló R, Huthala MF. Temperature rise in cavities prepared by high and low torque handpieces and Er:YAG laser. Br Dent J 2008; 205:E1; discussion 28-9. [PMID: 18535534 DOI: 10.1038/sj.bdj.2008.491] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2007] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The aim of this study was to compare intrapulpal temperature increases produced by a high-speed high-torque (speed-increasing) handpiece, a high-speed low-torque handpiece (air-turbine) and an Er:YAG (Erbium: Yttrium-Aluminum-Garnet) laser. SUBJECT AND METHODS Thirty bovine incisors were reduced to a dentine thickness of 2.0 mm. Class V preparations were prepared to a depth of 1.5 mm, measured with a caliper or by a mark on the burs. A thermocouple was placed inside the pulp chamber to determine temperature increases ( degrees C). Analysis was performed on the following groups (n = 10) treated with: G1, low-torque handpiece; G2, high-torque handpiece; and G3, Er:YAG laser (2.94 microm at 250 mJ/4 Hz), all with water cooling. The temperature increases were recorded with a computer linked to the thermocouples. RESULTS The data were submitted to ANOVA and Tukey statistical test. The average temperature rises were: 1.92+/-0.80 degrees C for G1, 1.34+/-0.86 degrees C for G2, and 0.75+/-0.39 degrees C for G3. There were significant statistical differences among the groups (p = 0.095). All the groups tested did not have a change of temperature that exceeds the threshold of 5.5 degrees C. CONCLUSION Temperature response to the low and high torque handpieces seemed to be similar, however the Er:YAG laser generated a lower temperature rise.
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Affiliation(s)
- L Firoozmand
- Faculty of Dentistry UNESP, Restorative Dentistry, Av. Eng. Francisco José Longo, 777 - Jd São Dimas, São José dos Campos 12245-000 SP, Brazil.
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Kojima T, Shimada K, Iwasaki H, Ito K. Inhibitory effects of a super pulsed carbon dioxide laser at low energy density on periodontopathic bacteria and lipopolysaccharidein vitro. J Periodontal Res 2005; 40:469-73. [PMID: 16302925 DOI: 10.1111/j.1600-0765.2005.00826.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE AND BACKGROUND Previous studies have described the effect of irradiation by a carbon dioxide (CO2) laser at high energy density on oral bacteria, and various side-effects have also been observed. However, no published studies have examined the effect of irradiation by a CO2 laser at low energy density on oral bacteria. The purpose of this study was to investigate the effects of super pulsed CO2 laser irradiation on periodontopathic bacteria and lipopolysaccharide (LPS). METHODS Bacterial suspensions of two species of periodontopathic bacteria received laser irradiation at energy densities of 0-12.5 J/cm2. The suspensions were then spread over agar plates and incubated anaerobically. The bactericidal effects were evaluated based on colony formation. Samples of LPS were laser-irradiated at energy densities of 0-12.5 J/cm2. The biological activity was measured, and LPS was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS The irradiation at low energy densities of 7.5 and 12.5 J/cm2 killed more than 99.9 and 99.999% of Porphyromonas gingivalis and more than 99% of Actinobacillus actinomycetemcomitans was sterilized by the irradiation at 7.5 J/cm2. LPS biological activity was significantly decreased by laser irradiation at energy densities of more than 7.5 J/cm2 (p < 0.05), and the components of LPS analyzed by SDS-PAGE was diminished non-specifically. CONCLUSION The results indicate that CO2 laser irradiation at low power is capable of bactericidal effect on periodontopathic bacteria and decreasing LPS activity.
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Affiliation(s)
- Taro Kojima
- Department of Periodontology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
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