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Ghadirian H, Geramy A, Shallal W, Heidari S, Noshiri N, Keshvad MA. The Effect of Remineralizing Agents With/Without CO 2 Laser Irradiation on Structural and Mechanical Properties of Enamel and its Shear Bond Strength to Orthodontic Brackets. J Lasers Med Sci 2020; 11:144-152. [PMID: 32273955 DOI: 10.34172/jlms.2020.25] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Introduction: Remineralizing agents may be used for the treatment of white spot lesions (WSLs) prior to bracket bonding. However, some concerns exist regarding their possible interference with the etching and bonding process, negatively affecting the bond strength. This study aimed to assess the effect of two remineralizing agents with/without CO2 laser irradiation on the mechanical properties and shear bond strength (SBS) of demineralized enamel to the orthodontic bracket. Methods: This study evaluated 60 premolar teeth in 6 groups (n=10) as follows: (I) sound enamel, (II) demineralized enamel, (III) Nupro remineralizing agent (N), (IV) Nupro and CO2 laser (N/L), (V) Teethmate remineralizing agent (T), and (VI) Teethmate and CO2 laser (T/L). The remineralizing agents were applied to the enamel surfaces after their immersion in a demineralizing solution for 5 days. In groups IV and VI, the CO2 laser with a 10.6 μm wavelength, 10 ms pulse duration, a 50 Hz repetition rate, 0.3 mm beam diameter and 0.7 W power was irradiated after applying the remineralizing agents. Brackets were bonded to the enamel surfaces and SBS was measured by a universal testing machine. For the assessment of enamel microhardness, 20 sections of molar teeth were divided into 4 groups (n=5; N, N/L, T, T/L) and their microhardness was measured before demineralization, after demineralization and after remineralization. X-ray diffraction (XRD) analysis, field-emission scanning electron microscopy (FESEM) and energy-dispersive spectrometry (EDS) were carried out to assess the formation of hydroxyapatite. The atomic percentages of the C, O, P, Ca, Na, Si, F and Ca/P ratio were determined by EDS analysis. Results: The SBS significantly decreased in group II (P<0.001). There was no significant difference among the groups I, III, IV, V and VI (P<0.05). This finding was similar to the microhardness results, which showed an increase in microhardness after remineralization (P<0.05), with no difference among the remineralizing agents. The Ca/P ratio was the highest in the Nupro group and the lowest in the demineralized group. Conclusion: Remineralizing agents can significantly improve the microhardness and structural properties of demineralized enamel to a level similar to that of sound enamel with no adverse effect on SBS to orthodontic brackets.
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Affiliation(s)
- Hannaneh Ghadirian
- Department of Orthodontics, School of Dentistry, Tehran University of Medical sciences, Tehran, Iran
| | - Allahyar Geramy
- Department of Orthodontics, School of Dentistry, Tehran University of Medical sciences, Tehran, Iran
| | | | - Soolmaz Heidari
- Department of Operative Dentistry, Dental Caries Prevention Research Center, Qazvin University of Medical Sciences, Qazvin, Iran
| | - Nooshin Noshiri
- Medical Image Processing Laboratory (MIPL), Department of Technology and Engineering, Alzahra University, Tehran, Iran
| | - Mohammad Ali Keshvad
- Department of Orthodontics, School of Dentistry, Tehran University of Medical sciences, Tehran, Iran
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Loiola ABDA, Aires CP, Curylofo-Zotti FA, Rodrigues Junior AL, Souza-Gabriel AE, Corona SAM. The Impact of CO 2 Laser Treatment and Acidulated Phosphate Fluoride on Enamel Demineralization and Biofilm Formation. J Lasers Med Sci 2019; 10:200-206. [PMID: 31749946 DOI: 10.15171/jlms.2019.32] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Introduction: This study evaluated the impact of CO2 laser treatment and acidulated phosphate fluoride (APF) on enamel demineralization and biofilm formation, using in vitro and in situ designs. Methods: Demineralized enamel slabs were distributed among 8 groups: placebo, placebo + continuous CO2 laser, placebo + repeated CO2 laser, placebo + ultrapulsed CO2 laser, 1.23% APF, APF + continuous CO2 laser, APF + repeated CO2 laser and APF + ultrapulsed CO2 laser. In the in vitro study, 15 enamel slabs from each group were subjected to a pH-cycling regimen for 14 days. In the cross over in situ design, 11 volunteers wore palatal appliances with demineralized enamel slabs for 2 periods of 14 days each. Drops of sucrose solution were dripped onto enamel slabs 8×/day. Biofilms formed on slabs were collected and the colony-forming units (CFU) of Streptococcus mutans and Lactobacillus were determined. Results: For both in vitro and in situ studies, there was no significant difference between treatments (P>0.05). However, all treatments increased microhardness of demineralized enamel (P<0.05). After a further in situ cariogenic challenge, with the exception of the placebo, all treatments maintained microhardness values (P<0.05). Microbiological analysis showed no difference in Streptococcus mutans (P>0.05) or Lactobacillus (P>0.05) counts between groups. Conclusion: The results suggest that APF gel combined with the CO2 laser, regardless of the pulse emission mode used, was effective in controlling enamel demineralization, but none of the tested treatments was able to prevent bacterial colonization.
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Affiliation(s)
- Ana Bárbara de Araújo Loiola
- Department of Restorative Dentistry, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto-SP, Brazil, 14040-904
| | - Carolina Patrícia Aires
- Department of Physics and Chemistry, Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo, Ribeirão Preto-SP, Brazil, 14040-904
| | - Fabiana Almeida Curylofo-Zotti
- Department of Restorative Dentistry, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto-SP, Brazil, 14040-904
| | - Antônio Luiz Rodrigues Junior
- Department of Social Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto-SP, Brazil, 14049- 900
| | - Aline Evangelista Souza-Gabriel
- Department of Restorative Dentistry, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto-SP, Brazil, 14040-904
| | - Silmara Aparecida Milori Corona
- Department of Restorative Dentistry, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto-SP, Brazil, 14040-904
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Mahmoudzadeh M, Rezaei-Soufi L, Farhadian N, Jamalian SF, Akbarzadeh M, Momeni M, Basamtabar M. Effect of CO2 Laser and Fluoride Varnish Application on Microhardness of Enamel Surface Around Orthodontic Brackets. J Lasers Med Sci 2017; 9:43-49. [PMID: 29399311 DOI: 10.15171/jlms.2018.10] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Introduction: Orthodontic treatment has many advantages such as esthetic improvement and self-esteem enhancement; yet it has some disadvantages such as increasing the risk of formation of white spot lesions, because it makes oral hygiene more difficult. It is rational to implement procedures to prevent these lesions. The present study was aimed to assess the effect of CO2 laser and fluoride varnish on the surface of the enamel surface microhardness around the orthodontic braces. Methods: Eighty extracted premolar teeth were selected, scaled, polished with nonfluoridated pumic and metal brackets were bonded to them. Then, they were randomly allocated to 5 groups: control (neither fluoride nor laser is used on enamel surfaces), fluoride (4 minutes fluoride varnish treatment of the enamel surfaces), CO2 laser (10.6 µm CO2 laser irradiation of the teeth), laserfluoride (fluoride application after laser irradiation) and fluoride-laser (fluoride was applied and then teeth were irradiated with laser). After surface treatment around brackets on enamel, the samples were stored in 0.1% thymol for less than 5 days and then they were exposed to a 10-day microbiological caries model. Microhardness values of enamel were evaluated with Vickers test. One sample of each group (5 teeth from 80 samples) was prepared for SEM (scanning electron microscopy) and the data from 75 remaining teeth were analyzed with analysis of variance (ANOVA) and chi-square tests (α =0.05). Results: Microhardness mean values from high to low were as follow: fluoride-laser, laser-fluoride, laser, fluoride and control. Microhardness in fluoride-laser group was significantly higher compared with that of the control group. Distribution adhesive remnant index (ARI) scores were significantly different between groups and most of bond failures occurred at the enamel-adhesive interface in groups 2 to 5 and at the adhesive-bracket interface in the control group. Conclusion: Combination of fluoride varnish and CO2 laser irradiation can reduce enamel demineralization around orthodontic brackets.
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Affiliation(s)
- Majid Mahmoudzadeh
- Orthodontics Department, Dental Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Loghman Rezaei-Soufi
- Department of Restorative Dentistry, Dental Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Nasrin Farhadian
- Orthodontics Department, Dental Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | | | - Mahdi Akbarzadeh
- Department of Biostatistics, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammadali Momeni
- Orthodontics Department, Dental Faculty, Shahrekord University of Medical Sciences, Chaleshtar, Shahrekord, Iran
| | - Masome Basamtabar
- Orthodontic Department, Dental Faculty, Kermanshah University of Medical Sciences, Kermanshah, Iran
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Paulos RS, Seino PY, Fukushima KA, Marques MM, de Almeida FCS, Ramalho KM, de Freitas PM, Brugnera A, Moreira MS. Effect of Nd:YAG and CO 2 Laser Irradiation on Prevention of Enamel Demineralization in Orthodontics: In Vitro Study. Photomed Laser Surg 2017; 35:282-286. [PMID: 28157423 DOI: 10.1089/pho.2016.4235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE The aim of this study was to investigate Nd:YAG and CO2 laser effects in the prevention of demineralization in deeper layers of enamel via successive acid challenge cycles. BACKGROUND DATA Lasers are promising in the prevention of enamel demineralization around the orthodontic brackets; however, there are very few studies that evaluate if the effects of treatment could be extended after successive acid challenge cycles due to permanent enamel structural alterations. MATERIALS AND METHODS Human enamel samples were divided into five groups (n = 12): G1-application of 1.23% acidulated fluoride phosphate gel (AFP, control); G2-Nd:YAG laser irradiation (0.6 W, 84.9 J/cm2, 10 Hz, 110 μs, contact mode); G3-Nd:YAG laser irradiation associated with AFP; G4-CO2 laser irradiation (0.5 W, 28.6 J/cm2, 50 Hz, 5 μs, and 10 mm focal distance); and G5-CO2 laser irradiation associated with AFP. The samples were submitted to successive acid challenge cycles. Quantitative light-induced fluorescence and scanning electron microscopy were used to assess enamel demineralization. The data were statistically compared (α = 5%). RESULTS G1: 50.87 ± 4.57; G2: 47.72 ± 2.87; G3: 50.96 ± 4.01; G4: 28.21 ± 2.19; and G5: 30.13 ± 6.38. The CO2 laser groups had significantly lower mineral losses than those observed in all other groups after successive acid challenge cycles. CONCLUSIONS Only the CO2 laser (10.6 μm) irradiation prevents enamel demineralization around the orthodontic brackets even after exposure to successive acid challenges. The CO2 laser at 10.6 μm showed a deeper effect in enamel regarding caries prevention.
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Affiliation(s)
- Renato Siva Paulos
- 1 Master Program in Biodentistry, Ibirapuera University , São Paulo, Brazil
| | | | | | - Marcia Martins Marques
- 2 Department of Restorative Dentistry, School of Dentistry, University of São Paulo , São Paulo, Brazil
| | | | | | | | - Aldo Brugnera
- 4 Department of Biomedicine Engineering, Camilo Castelo Branco University , São Paulo, Brazil
| | - Maria Stella Moreira
- 1 Master Program in Biodentistry, Ibirapuera University , São Paulo, Brazil .,2 Department of Restorative Dentistry, School of Dentistry, University of São Paulo , São Paulo, Brazil .,5 Universidade Nove de Julho , São Paulo, Brazil
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Rocha CT, Turssi CP, Rodrigues-Júnior AL, Corona SAM. Impact of CO2 laser and stannous fluoride on primary tooth erosion. Lasers Med Sci 2016; 31:567-71. [PMID: 26886587 DOI: 10.1007/s10103-016-1903-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 02/02/2016] [Indexed: 12/31/2022]
Abstract
This study evaluated in vitro the effect of input power of CO2 laser, either associated or not to stannous fluoride (SnF2) gel, for the control of intrinsic erosion in primary teeth. One hundred four enamel slabs (3 × 3 × 2 mm) from human primary molars were flattened and polished. Adhesive tapes were placed on their surface leaving a window of 3 × 1 mm. Slabs were then cycled four times in 0.01 M hydrochloric acid (pH 2, 2 min) and in artificial saliva (2 h) for creation of erosive lesions. Specimens were randomly assigned into eight groups (n = 13) according to fluoride application [absent (control) or 0.4% stannous fluoride gel (SnF2)] and input power of CO2 laser [unlased (control), 0.5, 1.0 or 1.5 W]. The CO2 laser irradiation was performed in an ultra-pulse mode (100 μs of pulse duration), 4-mm working distance, for 10 s. Specimens were then submitted to further erosive episodes for 5 days and evaluated for enamel relative permeability. Fluoride did not show any protective effect for any of the laser-treated groups or control (p = 0.185). However, a significant effect was detected for input power of CO2 laser (p = 0.037). Tukey's test showed that there was a significant statistically difference between specimens irradiated with 0.5 and 1.5 W (p = 0.028). The input power of 0.5 W showed lower permeability. Variation of input power CO2 laser can influence enamel permeability, at the power of 1.5 W which promoted greater permeability.
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Affiliation(s)
- Cristiane Tomaz Rocha
- Faculty of Dentistry, Sobral Campus, Federal University of Ceará, Rua Stanislau Frota, s/n, Centro, Sobral, CE, Brazil, 62.010-560.
| | - Cecilia Pedroso Turssi
- Department of Restorative Dentistry, São Leopoldo Mandic Institute and Dental Research Center, Rua Doutor José Rocha Junqueira, 13, Ponte Preta, Campinas, SP, CEP 13045-755, Brazil
| | - Antonio Luiz Rodrigues-Júnior
- Department of Social Medicine, Ribeirão Preto School of Medicine, University of São Paulo, Av. do Café, s/n, Monte Alegre, Ribeirão Preto, SP, CEP:14.040-904, Brazil
| | - Silmara Aparecida Milori Corona
- Department of Restorative Dentistry, Ribeirão Preto School of Dentistry, University of São Paulo, Av. do Café, s/n, Monte Alegre, Ribeirão Preto, SP, CEP:14.040-904, Brazil
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