# Introduction

aser-assisted bleaching is the best modality available in which laser accelerates release of free radicals within the bleaching gel to decrease time of whitening procedure. 1 In -office laser bleaching has an advantage of dentist control, avoidance of tissue exposure, minimal post bleaching hypersensitivity, reduced treatment time and enhanced patient satisfaction due to immediate results. 2 Laser whitening gels incorporate chromophores or activator specific to a particular wavelength which absorbs the laser light and quicken the bleaching process. 3 


# II.


# Case Discussion

A 15 year-old female patient reported to the Department of Pedodontics and Pediatric Dentistry with the chief complaint of discolored tooth with respect to her right upper front tooth region since childhood. On examination, generalized grade 2 dental fluorosis was seen and Grade 4 Dental flourosis irt 12 and 14. The patient was explained about the various treatment modalities available, the procedures to be undertaken and an informed consent was obtained.

A thorough oral prophylaxis was done 3 weeks prior and polishing of the teeth was done. On the day of treatment removal of surface plaque and stain with pumice prior to administration of whitening agent.

Modified Dean's Fluorosis Index (1942) was recorded at baseline and the end of the first and second visit, respectively. Preoperative photographs were taken at baseline [Figure 1]. The patient was asked to wear protective eyewear. The teeth were isolated using cotton rolls. A separating media was applied and a liquid dam was applied along the gingival margins (Figure 2 a). The liquid dam was cured using standard curing light, holding the handpiece at least 2cm from tooth for 5 to 10 seconds.


# Figure 1

Using an single tufted applicator tip apply 1 mm whitening gel 45% hydrogen peroxide (Figure 2 b) by mixing the two syringes containing activator and base till a uniform lavender colour(almost 20 times) is achieved according to manufacturer's recommenddations (Figure 3). After an even mix was obtained, a thin layer of about 1 mm thickness was applied on dried teeth with the brush tip applicator. Apply a disposable sleeve over the handpiece's arch to disperse laser light over a broad area of teeth (Figure 2 c).

The tooth was irradiated using diode laser (BIOLASE TM ) with a power setting 7W power, continuous wave mode and 200 J energy output in contact mode for a time of about 30 second for each quadrant [Figure 4]. The gel was left on the teeth for an additional 5 minutes to allow the teeth to absorb the laser activated hydrogen peroxide which allows continued whitening after laser exposures. This procedure was repeated twice witin a gap of 1 week. At the end clean rubber dam with explorer and rinse. Apply desensitizer potassium nitrate for 15 to 20 minutes (Figure 2 d). In case of any discomfort the patient was asked to report back to the clinic. Indirect Composite veneering was done on follow up visit. The postoperative photographs were taken (Figure 5c) .The color change evaluation using 3D Vita shade guide was noted.

The patient was advised not to consume products that stain teeth for up to the next 48 hours such as coffee, tobacco, tea, tomato sauce, cold drink etc.   


# Discussion

Initially bleaching was primarily performed with 35%-37% carbamide peroxide or 30%-40% hydrogen peroxide and the use of hydrogen peroxide (H 2 O 2 ) for conventional bleaching was introduced way back in 1884. 4,5,6 Light sources were marketed with the idea that light plays a significant role in tooth bleaching as catalyst for the ionization of Hydrogen peroxide in the bleaching gel and increasing the 7 Anaraki et al showed that the damage caused by bleaching with a 810 nm diode laser was less than the one caused by conventional bleaching without any laser activation. 4,5 Chromophores in the laser-activated gels absorb the narrow wavelength of diode lasers thereby increasing the efficacy of bleaching. 5 Its seen that the rate of the chemical reaction increases double fold with a rise of 10°C. Also the thickness of the bleaching gel layer is an important factor to ensure that the laser light can pass through this layer. The distance between the handpiece or fibre end and the gel is important criteria while considering the energy and impact of bleaching. 3 When Biolase Laserwhite20 TM is used in combination with a bleaching gel containing a chromophore (sulphorhodamine) photodynamic reactions occur (photochemical activation of the gel with limited photothermal activation). This combination of wavelength and specifically dyed bleaching gel also allows for safe bleaching (no damage of the enamel, no heating of the pulp) when the manufacturers instructions are followed. 3 IV.


# Conclusion

Vital bleaching is the cosmetic dental procedures asked by patients to seek a more pleasing smile. Laser bleaching causes profound quicker whitening with little or no surface alterations. The degree of whitening varies from patient to patient depends on type of stain, enamel thickness, tooth structure and age.
2![Figure 2: a): Placement of gingival barrier liquid dam b) Application of bleaching agent c) Applying biolase laser system d)Apply desensitizer](image-2.png "Figure 2 :")
4![Figure 4](image-3.png "Figure 4")
5![Figure 5: a) Preoperative photograph b) Post laser bleaching c) Composite veneering III.](image-4.png "Figure 5 :")
		
		
			

				


* 
	
		Comparison of laser and power bleaching techniques in tooth color change
		
			RFekrazad
		
		
			SAlimazandarani
		
		
			KamKalhori
		
		
			HAssadian
		
		
			SMMirmohammadi
		
	
	
		J Clin Exp Dent
		
			9
			4
			
			2017
		
	




* 
	
		Argon laser: a light source alternative for photopolymerization and inoffice tooth bleaching. General Dent
		
			ACassoni
		
		
			JARodrigues
		
		
			2007
			55
			416
		
	




* 
	
		Nine Shade Change by Laser-Assisted Teeth whitening
		
			MDang
		
		
			OShetty
		
	
	
		Int J Laser Dent
		
			3
			2
			
			2013
		
	




* 
	
		Evaluation of the effects of conventional versus laser bleaching techniques on enamel microroughness
		
			SNAnaraki
		
		
			SShahabi
		
		
			NChiniforush
		
		
			HNokhbatolfoghahaei
		
		
			HAssadian
		
		
			BYousefi
		
	
	
		Lasers Med Sci
		
			30
			
			2015
		
	




* 
	
		Efficacy of diode laser irradiation during dental bleaching in preventing enamel damage caused by bleaching
		
			ZAzarbayjani
		
		
			JafarzadehKashi
		
		
			TSErfan
		
		
			YChiniforush
		
		
			NRakhshan
		
		
			V
		
	
	
		Dent Res J
		
			15
			
			2018
		
	




* 
	
		Effect of home-use and in-office bleaching agents containing hydrogen peroxide associated with amorphous calcium phosphate on enamel microhardness and surface roughness
		
			DRDe Abreu
		
		
			RTSasaki
		
		
			FLAmaral
		
		
			FMFlório
		
		
			RTBasting
		
	
	
		J Esthet Restor Dent
		
			23
			
			2011
		
	




* 
	
		Laser teeth bleaching: evaluation of eventual side effects on enamel and the pulp and the efficiency in vitro and in vivo
		
			RJDe Moor
		
		
			JVerheyen
		
		
			PVerheyen
		
		
			ADiachuk
		
		
			MAMeire
		
		
			DeCoster
		
		
			PJ
		
		
			DeBruyne
		
		
			MKeulemans
		
		
			F
		
	
	
		Scientific World Journal
		
			835405
			2015. 2015