Laser therapy for dentine hypersensitivity

Effect of low-level laser therapy combined with 5000 parts per million fluoride dentifrice on postbleaching sensitivity: A clinical, randomized, and double-blind study

OBJECTIVE

The aim of this double-blind, randomized, controlled clinical study was to assess the efficacy of low-level laser therapy (LLLT) combined with 5000 ppm fluoride dentifrice on postbleaching sensitivity in teeth exposed to 35% hydrogen peroxide for four weeks.

MATERIALS AND METHODS

Twenty-five volunteers were evaluated using the split-mouth model in which the right and left maxillary/mandibular quadrants were randomized and allocated to one of two groups: GPLACEBO, in which the laser tip was positioned without the emission of light (placebo effect) + 5000 ppm sodium fluoride, or GLASER, which comprised LLLT + 5000 ppm sodium fluoride. For both groups, LLLT and placebo were used before bleaching, whereas fluoride was applied after bleaching. LLLT was applied at two points: on the central cervical and medial regions of the incisors, canines, and premolars in the corresponding hemi-arch. At each point, 60 J/cm² was applied for 16 seconds with an irradiance of 3.75 W/cm² using the therapeutic infrared device. To assess tooth sensitivity, a modified visual analogue scale was used after an evaporative stimulus, and a daily pain questionnaire was also applied.

RESULTS

The Wilcoxon and Friedman tests demonstrated a significant difference in the incidence of sensitivity pain between GPLACEBO and GLASER (P ≤ .05), with different evaluation times.

CONCLUSION

Teeth treated with laser therapy in combination with the topical use of sodium fluoride at each bleaching session demonstrated less sensitivity compared with the application of sodium fluoride only.

CLINICAL SIGNIFICANCE

The use of a low-level laser therapy in combination with topical use of sodium fluoride improves symptoms of dentin sensitivity at each bleaching session.

Effectiveness on oral pain of 808-nm diode laser used prior to composite restoration for symptomatic non-carious cervical lesions unresponsive to desensitizing agents

This study compares sensitivity reduction after dental restoration with and without prior diode laser (DL) irradiation for cervical dentine hypersensitivity (CDH) from non-carious cervical lesions (NCCLs) unresponsive to desensitizing agents. Eighty-eight teeth of 28 subjects (21 females; age 23-64 years), with CDH from NCCL were included in this study. NCCLs of each oral quadrant were randomized in two groups (study group (SG)) to estimate the sensitivity reduction after dental restoration (SG-1) compared with the DL irradiation used prior to restoration placement (SG-2). The subjects were asked to rate the sensitivity experienced during air stimulation using a visual analog scale before (baseline), immediately after, and at 6 and 12 months from restoration. The outcomes showed a significant reduction of discomfort compared to baseline for NCCLs of SG-2 with the decrease of 78.5, 78.9, and 78.1 % immediately and at 6 and 12 months after restoration, respectively; in comparison with the decrease of 70.1, 67, and 65.3 % for NCCLs of SG-1 immediately and at 6 and 12 months after restoration, respectively; and compared to baseline. The DL irradiation prior to dental restoration can further improve the painful symptomatology of CDH from NCCL unresponsive to desensitizing agents.

Laser-assisted treatment of dentinal hypersensitivity: a literature review

The purpose of this literature review was to evaluate the effectiveness of the laser-assisted treatment of dentinal hypersensitivity. A review with inclusion and exclusion criteria was performed from January 2009 to December 2014 with electronic data-bases: MedLine via PubMed, Science Direct and Cochrane Library. Research of paper magazines by hand was not considered. Forty-three articles were selected between literature reviews, in vitro studies, clinical trials, pilot and preliminary studies. The items were divided into laser-used groups for an accurate description, and then the reading of results into various typologies. Laser-assisted treatment reduces dentinal hypersensitivity-related pain, but also a psychosomatic component must be considered, so further studies and more suitable follow-ups are necessary.

Effect of Nd:YAG laser pulse energy on mercury vapor release from the dental amalgam

OBJECTIVE

The aim of this study was to evaluate the effect of different pulse energies of Nd:YAG laser on the amalgam ablation, and its effect on the amount of mercury vapor release from amalgam.

BACKGROUND DATA

Toxic vapor release from amalgam restorations at the laser focus site is possible.

MATERIALS AND METHODS

Forty-five amalgam samples (4 mm in diameter and 5 mm in height) were placed in sealed containers and underwent Nd:YAG laser irradiation with pulse energies of 50, 150, and 250 mJ at a distance of 1 mm from the amalgam surface for 4 sec. Subsequently, 150 mL of air was collected from the inside of the container using an Apex Pump to analyze the amount of mercury vapor in the air samples using a mercury vapor analyzer. Data were analyzed using Kruskal-Wallis and Mann-Whitney U tests (p<0.05).

RESULTS

The amount of mercury vapor release significantly increased with an increase in the pulse energy of Nd:YAG laser (p<0.001). In addition, the amount of mercury vapor release with 250 mJ pulse energy was significantly higher compared with the standard mercury vapor concentration (50 μg/m(3)) (p<0.001). Nd:YAG laser produced cavities on the amalgam surface, which increased in size with an increase in the energy of the laser beam.

CONCLUSIONS

The amount of mercury vapor significantly increased with an increase in the pulse energy of the laser beam, and was significantly higher than the standard mercury vapor concentration with 250 mJ pulse energy.

Dentinal tubules sealing by means of diode lasers (810 and 980 nm): a preliminary in vitro study

OBJECTIVE

The aim of this study was to evaluate the effect on dentinal surfaces of diode lasers (810 and 980 nm) at different parameters.

MATERIALS AND METHODS

Twenty-four caries-free human impacted wisdom teeth were used. The crowns were sectioned transversely in order to expose the dentin. The smear layer was removed by a 1 min application of ethylenediaminetetraacetic acid (EDTA). Each surface was divided into four quadrants irradiated at a different output power setting for each kind of laser: 0.8, 1, 1.6, and 2 W (energy densities: 2547, 3184, 5092, and 6366 J/cm(2), irradiation speed 1 mm/sec; optical fiber diameter: 200 μm; continuous and noncontact mode). Half of the samples were stained with a graphite paste. All specimens were sent for scanning electron microscopic (SEM) analysis. Pulp temperature increases in additional 20 teeth were measured by a thermocouple.

RESULTS

Diode laser irradiations at 0.8 and 1 W led to occlusion or narrowing of dentin tubules without provoking fissures or cracks. The application of graphite paste increased the thermal effects in dentin. Measurements of pulp temperature showed that irradiations at 0.8 and 1 W for a period of 10 sec in continuous mode increased pulp temperature (T ≤2°C).

CONCLUSIONS

Diode lasers (810 and 980 nm) used at 0.8 and 1 W for 10 sec in continuous mode were able to seal the dentin tubules. These parameters can be considered harmless for pulp vitality, and may be effective in the treatment of dentinal hypersensitivity.

The role of fluoride in the preventive management of dentin hypersensitivity and root caries

Objective

The objectives were to bring light on fluoride to control dentin hypersensitivity (DHS) and prevent root caries.

Materials and methods

Search strategy included papers mainly published in PubMed, Medline from October 2000 to October 2011.

Results

Fluoride toothpaste shows a fair effect on sensitive teeth when combined with dentin fluid-obstructing agents such as different metal ions, potassium, and oxalates. Fluoride in solution, gel, and varnish give an instant and long-term relief of dentin and bleaching hypersensitivity. Combined with laser technology, a limited additional positive effect is achieved. Prevention of root caries is favored by toothpaste with 5,000 ppm F and by fluoride rinsing with 0.025–0.1 % F solutions, as the application of fluoride gel or fluoride varnish three to four times a year. Fluoride measures with tablets, chewing gum, toothpick, and flossing may be questioned because of unfavorable cost effectiveness ratio.

Conclusion

Most fluoride preparations in combination with dentin fluid obstruction agents are beneficial to reduce DHS. Prevention of root caries is favorable with higher fluoride concentrations in, e.g., toothpaste.

Clinical relevance

Fluoride is an effective agent to control DHS and to prevent root caries particularly when used in higher concentrations.