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Year : 2018  |  Volume : 12  |  Issue : 2  |  Page : 70-73

Teeth bleaching using diode laser as an adjunct to a bleaching agent

1 Department of Periodontology, Rajarajeswari Dental College and Hospital, Bengaluru, Karnataka, India
2 Department of Periodontology, St Joseph Dental College, Eluru, Andhra Pradesh, India

Date of Web Publication19-Dec-2018

Correspondence Address:
Dr. Shivaprasad Bilichodmath
Department of Periodontology, Rajarajeswari Dental College and Hospital, #14, Ramohalli Cross, Kumbalgodu, Mysore Road, Bengaluru - 560 074, Karnataka
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jdl.jdl_10_18

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The use of hydrogen peroxide (H2O2) for conventional bleaching was introduced way back in 1884. Today bleaching products are often found in the form of gels containing various concentrations of carbamide peroxide and H2O2depending on the application and methods. Laser-assisted tooth bleaching has proven faster and efficient results. This case report emphasizes on the efficacy of diode laser for tooth bleaching. Opalescent® (Potassium nitrate and fluoride) was used as a bleaching gel. Diode laser (810 nm) was used to irradiate the tooth surfaces and microabrasion was carried out. Visible reduction in tooth discoloration was seen after a period of 3 weeks. On the basis of the results obtained, diode laser can be considered as an efficient and reliable treatment modality compared to conventional bleaching.

Keywords: Dental fluorosis, diode laser, tooth bleaching

How to cite this article:
Bilichodmath S, Gundapaneni V, Cecil A, Bilichodmath R. Teeth bleaching using diode laser as an adjunct to a bleaching agent. J Dent Lasers 2018;12:70-3

How to cite this URL:
Bilichodmath S, Gundapaneni V, Cecil A, Bilichodmath R. Teeth bleaching using diode laser as an adjunct to a bleaching agent. J Dent Lasers [serial online] 2018 [cited 2023 Sep 23];12:70-3. Available from:

  Introduction Top

The most commonly encountered tooth discoloration is due to fluorosis which is caused by an excessive intake of fluoride during formation and calcification of enamel. Various treatment modalities are available for tooth discolorations which indirectly improve esthetics. They include polishing, microabrasion, bleaching, and restoration through the direct or indirect composite veneers. Bleaching is a chemical process for whitening materials. In dentistry, bleaching usually refers to products containing some form of hydrogen peroxide (H2O2). The best known commercially available bleaching processes are peroxide, sodium perborate, chlorine, and chloride. Peroxide bleaching requires the least time and is most commonly used. H2O2 diffuses through the organic matrix of the enamel and dentin. It increases the permeability of the tooth structure, increasing the movement of ions through the tooth. H2O2 is a strong oxidizing agent and has the ability to generate strong, highly reactive free radical which will interact with most other organic molecules to achieve stability, generating other radicals. Simple molecules that absorb less and reflect more light are formed, creating a successful whitening action.

In-office bleaching procedures make use of different kind of energy sources such as plasma arc devices, halogen lamps, and light emitting diodes (LEDs) to increase the rate of chemical release of bleaching radicals. Light emitting long wavelengths have lower energy photons with a high thermal character, and these may induce unfavorable thermal effects. Shorter wavelengths such as the argon laser or potassium titanyl phosphate (KTP) laser have higher energy photons with less direct thermal characteristics.

KTP laser, argon, and diode lasers are commonly used for in-office bleaching treatments. Diode laser is a solid active medium laser which is manufactured from semiconductor crystals using some combination of aluminum or indium, gallium, and arsenic. The most common lasers of this group are the gallium-aluminum-arsenide laser (810 nm) and the indium-gallium-arsenide-phosphide laser (980 nm). They are operated in continuous wave and/or pulsed modes. They have a relatively poor absorption capacity in the vicinity of hard structures, soft-tissue surgeries can be safely performed in close proximity to enamel, dentin, and cementum. Diode laser irradiation may jeopardize pulp vitality during root surface instrumentation.

Wernish and Moritz demonstrated the importance of the use of an absorption agent in controlling the temperature increase inside the pulp, and in maintaining an enamel surface without alterations. Depth of penetration is directly proportional to the laser attenuation. Opalascent® (Potassium nitrate and fluoride) is an in-office chemically activated tooth whitening gel that contains potassium nitrate and fluoride, which helps maintain the health of enamel throughout the whitening process.

Very few studies are reported regarding the application of diode lasers in bleaching. Our present case is to emphasize on the efficacy of diode lasers in bleaching.

  Case Report Top

A 29-year-old male patient reported to the Department of Periodontology of Rajarajeswari Dental College with the chief complaint of discolored tooth with respect to his upper front tooth region since childhood. On examination, generalized fluorosis was seen. The patient was explained about the various treatment modalities and the procedure to be undertaken and informed consent was obtained.

A thorough oral prophylaxis was done and polishing of the teeth was done using pumice. The patient was advised a minimum of three sittings with a gap of 1 week between each visit. Modified Dean's Fluorosis Index (1942) was recorded at baseline and the end of the first, second, and third visit, respectively. Preoperative photographs were taken at baseline [Figure 1]. The tooth was isolated using cotton rolls. The patient was asked to wear protective eyewear. The gingival barrier was applied along the gingival margins.
Figure 1: Preoperative photograph

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Opalescent® (Potassium nitrate and fluoride) was applied to the teeth using single-tufted brush [Figure 2]. The tooth was irradiated using 810-nm diode laser (Zolar®) with a power setting ranging from 1 to 5 W in contact mode for a time of about 5 s per tooth [Figure 3]. This procedure was repeated three times per visit for three visits with a gap of 1 week between each visit. In case of any discomfort, the patient was asked to report back to the clinic. No incidence of any discomfort or irritation was reported by the patient. At the third visit, microabrasion was carried out with respect to the maxillary right and left central incisors. The postoperative photographs were taken following each visit.
Figure 2: Placement of gingival barrier and application of bleaching agent

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Figure 3: Tooth irradiation with diode laser

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  Results Top

Modified Dean's Fluorosis Index at the baseline was scored as 3 (moderate). Following the first visit, there was slight reduction in the brownish discoloration of the teeth and the score was given as 3 [Figure 4]. At the end of the third visit following microabrasion, there was a visible reduction in the brownish discoloration of the teeth and the modified DFI score was 2 (mild) [Figure 5].
Figure 4: Intraoral photograph at the first visit

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Figure 5: At the end of the third visit following microabrasion – postoperative photograph

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  Discussion Top

Potential adverse effects of conventional tooth bleaching include cervical root resorption, pulp sensitivity, alteration of the enamel surface which involves changes in microhardness, presence of porosities, changes in surface roughness, reduction in fracture toughness, alteration of calcium to phosphate ratio, erosion, and decrease in abrasion resistance.[1]

Power bleaching which originated with Abbot in 1918 and progressed to heat lamps and heated spatulas in 1980's, has been effective but has many side effects including pulpal necrosis caused by the inability to control the highly reactive and caustic 35% H2O2. Their main goal is to efficiently whiten the tooth using controlled temperature elevation of the H2O2 to prevent pulpal necrosis. The objective of power bleaching is to excite the bleaching agents using a very efficient source of light energy. The greater the exposure time of the bleaching agent to the tooth, the greater is the risk of pulpal necrosis. When a light of a specific wavelength is used that approximates the absorption spectrum of the bleaching agent, the chemical reaction proceeds at a faster rate, thereby decreasing exposure time of the bleaching agent to the tooth.[2]

Intrapulpal temperature of >5.5°C will cause irreversible pulpal damage. High-power diode lasers (784–980 nm) should be used in combination with a bleaching gel as they are known to cause rise in pulpal temperature. A temperature increase of 16°C in the pulpal chamber was noted when 830 nm diode laser (30 s, 3 W) was used without the application of gel, while only 8.7°C temperature increase was recorded when gel was used during laser activation.[3] The increase in the pulp chamber temperature with a diode laser used at 1–2 W is below the critical temperature.[4] There is conflicting evidence on the effects of bleaching lights on tooth color change as most of studies comparing effectiveness of in-office bleaching with or without light application were conducted in vitro. The effects on tooth color change were variable and some differences detected digitally were not detectable visually.[5]

Klunboot et al. conducted a study which evaluated the effectiveness of diode laser on tooth enamel surface in the tooth whitening and found out that diode laser at low-power densities was highly efficient in tooth bleaching.[6]

Wetter et al. conducted an in vitro study which compared the bleaching efficiency between LED and diode laser irradiation using two bleaching agents, namely, Opalescence X-tra and HP Whiteness. The authors of the study concluded that bleaching efficiency using diode laser with HP Whiteness agents was comparatively better than LED irradiation and with Opalescence X-tra.[7]

Abdelfattah conducted a study which compared the use of laser and nonlaser systems in tooth bleaching. The authors concluded that laser-assisted tooth bleaching was comparatively better. Among lasers, they evaluated diode and Er:YAG laser and concluded that Er:YAG was comparatively better than diode laser.[8]

Mathews et al. conducted a study which compared the clinical efficacy of in-office bleaching system using a titanium dioxide impregnated bleaching gel in conjunction with an 810-nm diode laser as opposed to a conventional in-office bleaching system. The results showed that there was absolutely no difference in the brightness obtained by both laser bleaching and conventional in-office bleaching.[9]

Lagori et al. conducted an in vitro study to compare the bleaching efficiency of KTP lasers and diode laser on teeth stained with different substances. Three groups of 45 bovine teeth were created and immersed for 1 week in a solution of tea, coffee, or red fruits, respectively. Each group was divided into three subgroups of 15 teeth. One was bleached with a 30% H2O2 gel for 30 min only as control, another 15 teeth group was bleached with the gel plus 810-nm diode laser irradiation and the last group was bleached with the gel plus KTP irradiation. The lasers were applied in three cycles of 30 s each with a power of 1.5 W localized on a 10 mm spot on the teeth. The results showed that diode laser was effective only at bleaching teeth stained with coffee; meanwhile, the KTP laser was efficient at bleaching teeth with coffee, tea, and red fruits stains.[10]

The diode laser provides quick and effective results when used to activate the bleaching gel. An in vitro study concluded that diode laser activation of bleaching agent presented significantly better results as compared to the agent being used alone or when combined with the LED source. An added advantage is the reduced contact time of the bleaching agent with the teeth, and this minimizes the chances of sensitivity or irritation.[7]

  Conclusion Top

From the results of the present case report, we can conclude that diode laser can be considered as an effective treatment option for bleaching when used along with a bleaching agent. The reduced time frame required to achieve the results may lead to high patient compliance and satisfaction. However, further long-term studies have to be conducted to prove the efficacy of laser treatment in bleaching.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Goldberg M, Grootveld M, Lynch E. Undesirable and adverse effects of tooth-whitening products: A review. Clin Oral Investig 2010;14:1-0.  Back to cited text no. 1
Convissar R. Principles and Practice of Laser Dentistry. St. Louis, Missouri: Elsevier Mosby; 2012. p. 150-1.  Back to cited text no. 2
Sulieman M, Addy M, Rees JS. Surface and intra-pulpal temperature rises during tooth bleaching: An in vitro study. Br Dent J 2005;199:37-40.  Back to cited text no. 3
Sulieman M, Rees JS, Addy M. Surface and pulp chamber temperature rises during tooth bleaching using a diode laser: A study in vitro. Br Dent J 2006;200:631-4.  Back to cited text no. 4
Niladari M. Vital tooth bleaching: A case report. Am J Adv Med Sci 2014;2:1-6.  Back to cited text no. 5
Klunboot U, Arayathanitkul K, Chitaree R, Emarat N. Effective of diode laser on teeth enamel in the teeth whitening treatment. Proc of SPIE 2011:8311 83111H:1-8. Doi: 10.1117/12.904472.  Back to cited text no. 6
Wetter NU, Barroso MC, Pelino JE. Dental bleaching efficacy with diode laser and LED irradiation: An in vitro study. Lasers Surg Med 2004;35:254-8.  Back to cited text no. 7
Abdelfattah MM. Different types of laser use in teeth bleaching. J Med Med Sci 2014;5:230-7.  Back to cited text no. 8
Mathews A, Mariam R, Sudeep S. Clinical evaluation of laser bleaching vs. Conventional inoffice bleaching. J Dent Laser 2013;2:54-8.  Back to cited text no. 9
Lagori G, Vescovi P, Merigo E, Meleti M, Fornaini C. The bleaching efficiency of KTP and diode 810 nm lasers on teeth stained with different substances: An in vitro study. Laser Ther 2014;23:21-30.  Back to cited text no. 10


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]

This article has been cited by
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