Effects of Irradiation of Continuous Wave Carbon Dioxide Laser on Caries Resistance of Deciduous Teeth (original) (raw)

Carbon dioxide laser in dental caries prevention

Journal of Dentistry, 2004

Objectives. To describe CO 2 laser characteristics and to review the literature regarding its effects on caries inhibition in enamel and dentin. Another aim of this review is to discuss the effects of CO 2 laser in combination with fluoride.

Inhibition of caries in vital teeth by CO2 laser treatment

Lasers in Dentistry XIV, 2008

In multiple well-controlled laboratory studies enhancing caries resistance of enamel has been successfully reported using short-pulsed 9.6 µm CO 2 laser irradiation. The aim of this study was to prove in a short term clinical pilot trial that the use of the CO 2 laser will significantly inhibit the formation of carious lesions around orthodontic brackets in vivo in comparison to a non-irradiated control area. Twelve subjects scheduled for extraction of premolars for orthodontic treatment reasons with an average age of 14.6 years were recruited for the 4-week study. Orthodontic brackets were placed on those premolars with a conventional composite resin (Transbond XT, 3M Unitek, REF 712-035) and a defined area next to the bracket was irradiated with a CO 2 laser, Pulse System, Inc (PSI) (Model #LPS-500, Los Alamos, New Mexico), wavelength 9.6 µm, pulse duration 20 µs, pulse repetition rate 20 Hz, beam diameter 1,100 µm, average fluence 4.31 +/-0.11 J/cm 2 , 20 laser pulses per spot. Premolars were extracted after four weeks for a quantitative assessment of demineralization by cross sectional microhardness testing. The relative mineral loss ∆Z (vol% x µm) for the laser treated enamel was 402 +/-85 (SE) while the control area showed a significantly higher mineral loss (mean ∆Z 738 +/-131; P=0.04, unpaired t-test). The laser treatment produced a 46% demineralization inhibition around the orthodontic brackets in comparison to the non-laser treated areas. This study showed, for the first time that a pulsed 9.6 µm CO 2 laser works for the prevention of dental caries in the enamel in vital teeth in human mouths.

In vitro CO2 9.3-μm short-pulsed laser caries prevention—effects of a newly developed laser irradiation pattern

Lasers in Medical Science, 2020

Caries prevention with different lasers has been investigated in laboratory studies and clinical pilot trials. Objective of this in vitro study was to assess whether 9.3-μm microsecond short-pulsed CO 2 laser irradiation enhances enamel caries resistance without melting, with and without additional fluoride application. Seven groups of enamel, totaling 105 human enamel samples, were irradiated with 2 different carbon dioxide lasers with 2 different energy application systems (original versus spread beam; 9.3 μm wavelength, pulse repetition rate 43 Hz vs 100 Hz, fluence ranges from 1.4 to 3.9 J/cm 2 , pulse duration 3 μs to 18 μs). The laboratory pH-cycling was performed with or without additional fluoride, followed by cross-sectional microhardness testing. To assess caries inhibition, the mean relative mineral loss delta Z (ΔZ) was determined. To evaluate for melting, scanning electron microscopy (SEM) examinations were performed. For the non-laser control groups with additional fluoride use, the relative mineral loss (ΔZ, vol% × μm) ranged between 512 ± 292 and 809 ± 297 (mean ± SD). ΔZ for the laser-irradiated samples with fluoride use ranged between 186 ± 214 and 374 ± 191, averaging a 58% ± 6% mineral loss reduction (ANOVA, P < 0.01 to P < 0.0001). For the non-laser-treated controls without additional fluoride, the mineral loss increased (ΔZ 914 ± 422 to 1224 ± 736). In contrast, the ΔZ for the laser-treated groups without additional fluoride ranged between 463 ± 190 and 594 ± 272 (P < 0.01 to P < 0.001) indicative of 50% ± 2% average reduction in mineral loss. Enhanced caries resistance was achieved by all applied fluences. Using the spread beam resulted in enhanced resistance without enamel melting as seen by SEM. CO 2 9.3-μm short-pulsed laser irradiation with both laser beam configurations resulted in highly significant reduction in enamel mineral loss. Modifying the beam to a more homogenous profile will allow enamel caries resistance even without apparent enamel melting.

Histologic analysis of the effect on dental pulp of a 9.6-?m CO2 laser

Lasers in Surgery and Medicine, 2002

Background and Objective: Both patients and dentists would like a replacement of the dental drill. During the last decade, lasers have been investigated as a possible replacement. For lasers to be accepted, studies must show that their effect on the dental pulpal tissues is equal to or less noxious than those effects caused by the dental handpiece (drill). Study Design/Materials and Methods: In this study, two laser systems were used; the first was a breadboard CO 2 laser and the second a prototype clinical CO 2 laser system both emitted 60-ms-long pulses of 9.6-mm radiation. On the delivery system of both lasers, a scanner moved the focussed beam in a circular pattern and a water spray system served to cool the ablation site. Both lasers were used to create holes of similar dimensions in canine teeth. The treated teeth were then restored and harvested at either 4 days or 4 weeks. The teeth were decalcified, sectioned, and stained for examination via light microscopy. Results: The histologic examination revealed normal pulpal tissues in the canine teeth treated with both CO 2 lasers. Some histologic sections showed an increase in the predentin layer, 28 days after laser treatment. While many histologic sections showed normal pulpal architecture following handpiece treatment, some sections showed total disruption of the normal pulpal histology. Conclusions: Histologic evaluation revealed that the lasers produced no noticeable damage to the dental pulpal tissue and appear to be a safe method for removing dental hard tissues. From this study, it appears that 9.6 mm CO 2 laser does not cause damage to the dental pulpal tissues in dogs.

Carbon dioxide laser oral safety parameters for teeth

Lasers in Surgery and Medicine, 1990

The carbon dioxide laser is used in the oral cavity for a variety of procedures. Although the procedures may not involve the teeth directly, precaution should be exercised to preserve their integrity. The results of this study indicate that the most limiting parameter for oral use of the CO, laser is damage to the enamel surface, which could be inflicted with as little as 5 W for 0.2 second and a 1 mm beam. Care should be exercised to prevent inadvertent damage to the surface enamel of teeth even at very low energy levels.

Lasers effects on enamel for caries prevention

2006

The aim of this study was to ascertain whether laser irradiation is able to reduce caries incidence. For this purpose, the effects of laser on enamel and on fluoride uptake were discussed. Current literature regarding the preventive effect of laser irradiation on dental hard tissue has been reviewed. An evaluation of the results of the available in vitro and in vivo studies on the efficacy of anticaries and induced changes on enamel by laser irradiation were also performed. Articles were selected using the Medline, Web of Science, Embase, and Cochrane databases, and the results of these studies were described. The most common lasers employed for caries prevention on enamel are Nd:YAG; CO 2 ; Er:YAG; Er,Cr:YSGG; and argon. The percentage of inhibition of dental caries varied from 30 to 97.2%, and the association with fluoride has demonstrated the best results on inhibition of caries development. Laser irradiation under specific conditions can change the crystallographic properties of apatite crystals, increasing the acid resistance of lased enamel. The combined treatment of laser irradiation with fluoride propitiates an expressive fluoride uptake, reducing the progression of carieslike lesions, and this treatment is more effective than laser or fluoride alone. Available data suggest that lasers combined with fluoride is a promising treatment in caries prevention.