scholarly journals Chemical Changes of Enamel Produced by Sodium Fluoride, Hydroxyapatite, Er:YAG Laser, and Combined Treatments

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Alma Yadira Ceballos-Jiménez ◽  
Laura Emma Rodríguez-Vilchis ◽  
Rosalía Contreras-Bulnes ◽  
Jesús Arenas Alatorre ◽  
Rogelio José Scougall-Vilchis ◽  
...  

Occlusal pits and fissures of permanent molars are considered to have higher risk of developing caries. Enamel demineralization can be prevented by applying remineralizing agents, and their absorption increases with prior irradiation. This work evaluates the chemical changes produced by treating occlusal surfaces with sodium fluoride (NaF), hydroxyapatite-NaF-xylitol (HA-NaF-X), Er:YAG laser irradiation (L), and combinations thereof. Fifty enamel samples were randomly assigned to five groups (n=10): NaF, HA-NaF-X, L, L + NaF, and L + HA-NaF-X. The chemical composition of human enamel was evaluated before (BT) and after (AT) treatment using energy-dispersive X-ray spectroscopy (EDS) and expressed in atomic percentages (at%). For combined treatment groups, the products were applied after laser irradiation. The statistical analyses included a pairedt-test and ANOVA (p≤0.05). After treatment, a significant increase in F at% was observed in the NaF group (2.71 ± 1.41). The irradiated groups showed significant increases in Ca and P at% and the Ca/P ratio. The highest values occurred for L + NaF (30.44 ± 4.28 Ca at%, 11.97 ± 1.45 P at%, and 2.55 ± 0.22 Ca/P ratio). Er:YAG laser irradiation alone or in combined protocols increased the Ca and P content of dental enamel, in vitro.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Konstantin Johannes Scholz ◽  
Marianne Federlin ◽  
Karl-Anton Hiller ◽  
Helga Ebensberger ◽  
Gerlinde Ferstl ◽  
...  

Abstract One mechanism of action for the anticaries effect of topical fluoridation is through precipitation of CaF2. In this in vitro study energy-dispersive x-ray spectroscopy (EDX) is used as a semiquantitative method to detect enamel fluoride-precipitation under the influence of acidic and neutral pH-value and absence or presence of a salivary pellicle. Crowns of 30 human caries-free third molars were quartered into four specimens and the enamel surface ground flat and polished. Two specimens each were stored in human saliva (120 minutes pellicle formation). Teeth were randomly allocated into 6 treatment groups: NaF_a (experimental acidic sodium fluoride; 12500 ppmF−, pH 4.75); NaF_n (experimental neutral sodium fluoride; 12500 ppmF−, pH 7.0); GB_a (acidic gel base; 0 ppmF−, pH 4.75); GB_n (neutral gel base; 0 ppmF−, pH 7.0); AmF-NaF_a (experimental acidic amine/sodium fluoride; 12500 ppmF−, pH 4.75); EG_a (acidic amine/sodium fluoride; Elmex Geleé, CP-GABA GmbH; 12500 ppmF−, pH 4.75). Each gel was applied for 60 seconds to one specimen with and one specimen without pellicle. Two specimens served as controls (no gel, without/with pellicle). Atomic percent (At%) of O, F, Na, Mg, P, Ca was measured by EDX. ∆At% and Ca/P-ratios were calculated. EDX could semi-quantify superficial enamel fluoride-precipitation. Only specimens treated with acidic fluoride gels showed fluoride-precipitation, a salivary pellicle tended to decrease At%F.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Feyza Ulkur ◽  
Elif Sungurtekin Ekçi ◽  
Didem Nalbantgil ◽  
Nuket Sandalli

The aim of thisin vitrowas to evaluate the effects of tricalcium phosphate (TCP) and amorphous calcium phosphate (ACP) containing varnish materials and Er:YAG laser irradiation on enamel demineralization around orthodontic brackets. Forty extracted human premolar teeth were randomly divided into four treatment groups (i.e., 10 in each group): (1) 5% NaF-ACP varnish, (2) 5% NaF-TCP varnish, (3) Er:YAG laser, and (4) control (no treatment). Er:YAG laser was operated at a wavelength of 2.94 μm and the energy output was 80 mJ per pulse; a pulse duration of 200 μsec and and a frequency of 2 Hz were used with water cooling. All samples were then put into pH cycles. Surface microhardness values and representative SEM images were assessed. Surface microhardness values were evaluated using Kruskal-Wallis and Mann-WhitneyUtests. The results revealed that demineralization was significantly lower in the TCP and ACP varnish groups, whereas mean surface microhardness values of the TCP varnish were found higher than the ACP(P<0.05). TCP and ACP varnish materials were found effective for reducing enamel demineralization around orthodontic brackets. Use of Er:YAG laser irradiation as described in this study for inhibition of demineralization was found not satisfactory.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Jennifer Manuela Díaz-Monroy ◽  
Rosalía Contreras-Bulnes ◽  
Oscar Fernando Olea-Mejía ◽  
María Magdalena García-Fabila ◽  
Laura Emma Rodríguez-Vilchis ◽  
...  

Background. An increase in the acid resistance of dental enamel, as well as morphological and structural changes produced by Er:YAG laser irradiation, has been reported.Purpose. To evaluate the chemical changes associated with acid resistance of enamel treated with Er:YAG laser.Methods. Forty-eight enamel samples were divided into 4 groups (n=12). Group I (control); Groups II, III, and IV were irradiated with Er:YAG at 100 mJ (12.7 J/cm2), 200 mJ (25.5 J/cm2), and 300 mJ (38.2 J/cm2), respectively.Results. There were significant differences in composition of irradiated groups (with the exception of chlorine) and in the amount of calcium released.Conclusions. Chemical changes associated with an increase in acid resistance of enamel treated with Er:YAG laser showed a clear postirradiation pattern characterized by a decrease in C at.% and an increase in O, P, and Ca at.% and no changes in Cl at.%. An increased Ca/P ratio after Er:YAG laser irradiation was associated with the use of higher laser energy densities. Chemical changes produced by acid dissolution showed a similar trend among experimental groups. Stable or increased Ca/P ratio after acid dissolution was observed in the irradiated groups, with reduction of Ca released into the acid solution.


Author(s):  
M. John Hicks

Acid-etching of enamel surfaces has been performed routinely to bond adhesive resin materials to sound dental enamel as a caries-preventive measure. The effect of fluoride pretreatment on acid-etching of enamel has been reported to produce inconsistent and unsatisfactory etching patterns. The failure to obtain an adequate etch has been postulated to be due to fluoride precipitation products deposited on the enamel surface. The purpose of this study was to evaluate the effects of fluoride pretreatment on acid-etching of carieslike lesions of human dental enamel.Caries-like lesions of enamel were created in vitro on human molar and premolar teeth. The teeth were divided into two fluoride treatment groups. The specimens were exposed for 4 minutes to either a 2% Sodium Fluoride (NaF) solution or a 10% Stannous Fluoride (SnF2) solution. The specimens were then washed in deionized-distilled water. Each tooth was sectioned into four test regions. This was carried out to compare the effects of various time exposures (0 to 2 minutes) and differing concentrations (10 to 60% w/w) of phosphoric acid (H3PO4) on etching of caries-like lesions. Standard preparation techniques for SEM were performed on the specimens.


2004 ◽  
Vol 841 ◽  
Author(s):  
Michelle E. Dickinson ◽  
Adrian B. Mann

ABSTRACTSalivary pellicle is an organic biofilm formed by the physisorption of proteins and carbohydrates onto the surface of dental enamel exposed to the oral environment. The pellicle has several key roles in oral physiology including lubrication and reduction of friction between teeth during mastication, as well as chemical protection of the enamel against acidic solutions. However, pellicle proteins are known to react with dietary compounds to cause extrinsic staining on the tooth surface.In this study, nanoindentation and AFM have been used in vitro to examine the acquired salivary pellicle formed in vivo on dental enamel. The mechanical properties, growth, structure and morphology of pellicle grown in vivo on human enamel surfaces have been analysed. In addition, the effects of dietary agents such as polyphenols on the pellicle's morphology and properties have been studied.It was found that initial adsorption of proteins on the enamel surface occurred within 30 seconds of exposure to the oral cavity, with full growth achieved within 2 hours. Differences in the properties of the pellicles such as surface adhesion, and time dependent effects due to polyphenol interaction were measured using nanoindentation. It was seen that the polyphenol interaction has a significant effect on these properties. These results suggest that the stained pellicle is mechanically stiffer, but also less viscous and more fluid like. This could explain why traditional tooth brushing techniques do not efficiently remove this layer.


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.


2014 ◽  
Vol 15 (3) ◽  
pp. 283-287 ◽  
Author(s):  
Mateus Rodrigues Tonetto ◽  
Marcelo Ferrarezi de Andrade ◽  
Shelon Cristina Souza Pinto ◽  
Darlon Martins Lima ◽  
José Roberto Cury Saad ◽  
...  

ABSTRACT Ideally projected to be applied on soft tissues, infrared lasers were improved by restorative dentistry to be used in hard dental tissues cavity preparations — namely enamel and dentin. This paper evidentiates the relevant aspects of infrared Erbium laser's action mechanism and its effects, and characterizes the different effects deriving from the laser's beams emission. The criteria for use and selection of optimal parameters for the correct application of laser systems and influence of supporting factors on the process, such as water amount and its presence in the ablation process, protection exerted by the plasma shielding and structural factors, which are indispensable in dental tissues cavity preparation related to restorative technique, are subordinated to optical modifications caused by the interaction of the energy dissipated by these laser light emission systems in the targeted tissue substrate. Clinical relevance Differences in the action of infrared Erbium laser system in regard to the nature of the ablation process and variations on the morphological aspects observed in the superficial structure of the target tissue irradiated, may be correlated to the structural optical modifications of the substrate produced by an interaction of the energy propagated by laser systems. How to cite this article Lima DM, Tonetto MR, de Mendonça AAM, Elossais AA, Saad JRC, de Andrade MF, Pinto SCS, Bandéca MC. Human Dental Enamel and Dentin Structural Effects after Er:yag Laser Irradiation. J Contemp Dent Pract 2014;15(3):283-287.


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.


1997 ◽  
Vol 41 (9) ◽  
pp. 2006-2008 ◽  
Author(s):  
J R Forney ◽  
S Yang ◽  
M C Healey

The combined effect of the serine protease inhibitor alpha-1-antitrypsin (AAT) and the aminoglycoside paromomycin on Cryptosporidium parvum infection in vitro was investigated. AAT and paromomycin were mixed with C. parvum oocysts as either single or combined treatments and used to inoculate epithelial cell cultures. Single- and combined-treatment groups had significantly lower (P < 0.01) parasite numbers than untreated controls. The mean fractional inhibitory concentration indices suggested significant synergistic activity.


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.


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