J Interdiscip Dentistry
Home | About JID | Editors | Search | Ahead of print | Current Issue | Archives | Instructions |
Home Print this page Email this page Small font sizeDefault font sizeIncrease font size
Users Online: 135  | Login  | Contact us | Advertise | Subscribe  

Table of Contents
Year : 2015  |  Volume : 5  |  Issue : 2  |  Page : 71-74

Diode laser and fluoride varnish in the management of dentin hypersensitivity

Department of Periodontology, Manipal College of Dental Sciences, Manipal University, Mangalore, Karnataka, India

Date of Web Publication5-Jan-2016

Correspondence Address:
P Rohit Jain
Department of Periodontology, Manipal College of Dental Sciences, Manipal University, Mangalore, Karnataka
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2229-5194.173226

Rights and Permissions

Aims: The aim of this study is to compare the effectiveness of diode laser in combination with commercially available fluoride varnish to the fluoride varnish alone. Settings and Design: Randomized control trial; split mouth. Subjects and Methods: A total of 50 teeth from 14 patients with visual analog scale (VAS) >2 from both sexes were randomly allocated into two groups: 26 teeth in bifluoride group and 24 in laser + bifluoride group. Dentine hypersensitivity is evaluated with the help of VAS at the start of study, at 15 min; 15, 30, and 60 days. Teeth were subjected to vitality testing to rule out any pulpal pathology. Statistical Analysis Used: SPSS version 17.0. Unpaired t test. Results: After 15 min both the treatment modalities were effective. The effectiveness of fluoride varnish in reducing evaporative stimulus (ES) was maintained until 15 days. However, the laser + fluoride varnish was more effective in reducing thermal stimulus (TS) at 15 days. At any given point of time, the effectiveness of laser + fluoride varnish was more than the varnish group. The effectiveness of laser also reduced after 30 days for both ES and TS. Conclusions: The diode laser and fluoride varnish are effective in the treatment of dentin hypersensitivity. The combined effect is more than fluoride varnish alone, but for a short period.

Keywords: Dentin hypersensitivity, diode laser, fluoride varnish

How to cite this article:
Jain P R, Naik G D, Uppor S A, Kamath DG. Diode laser and fluoride varnish in the management of dentin hypersensitivity. J Interdiscip Dentistry 2015;5:71-4

How to cite this URL:
Jain P R, Naik G D, Uppor S A, Kamath DG. Diode laser and fluoride varnish in the management of dentin hypersensitivity. J Interdiscip Dentistry [serial online] 2015 [cited 2023 Mar 30];5:71-4. Available from: https://www.jidonline.com/text.asp?2015/5/2/71/173226

   Introduction Top

Dentine hypersensitivity is one of the most common complaint for which the patients visit a dentist. Is characterized by short, sharp pain arising from exposed dentine in response to stimuli typically thermal, evaporative, tactile, osmotic, or chemical and which cannot be ascribed to any other form of dental defect or pathology.[1] The degree of severity of pain can be quantified by means of a descriptive scale: slight, moderate or intense pain, or a visual analogue scale (VAS): 0-10.[2] The most frequent reasons for exposure of dentine are attrition caused by occlusal disharmony, abrasion gingival recession following either a periodontal disease process or periodontal therapy and trauma from tooth brushing. According to Brannstrom's hydrodynamics theory,[3] the most widely accepted, dentine hypersensitivity results when stimuli applied to dentine displace the fluid inside dentinal tubules inwardly or outwardly. The desensitizing agents are usually divided into two: The therapeutic tubule occlusive agents and those with effect on the depolarization of nerve endings. The use of fluoridating varnishes with sodium fluoride (NaF) (in high concentrations) as the active ingredient has been advocated to increase the time of action of NaF in contact with exposed dentin, thus aiming to enhance its effectiveness in decreasing dentine sensitivity.[4],[5] However, the attempt to provide tubule closure or narrowing is relatively short-lived because the varnish has a gradual therapeutic action (progressive in time) and can be removed during tooth brushing, before its desensitizing effect may be achieved.[5] The advent of lasers has opened another option in the management of dentinal hypersensitivity. Various type of lasers have been used such as neodymium-doped yttrium aluminum garnet (Nd: YAG), erbium-doped yttrium aluminum garnet (Er: YAG), CO2 and diode lasers for treating dentin hypersensitivity. Diode laser has enabled hypersensitivity reduction equal or superior to conventional treatments such as potassium nitrate, stannous fluoride, and NaF.[6] Low level lasers have antiinflammatory effects while middle output power lasers have harmful effects on pulp. Therefore, the aim of this study is to evaluate whether the use of diode laser prolongs the effectiveness of fluoride varnish and whether the combined use has any additional advantage over using fluoride varnish alone.

   Subjects and Methods Top

The research protocol was initially submitted to appreciation of Ethics Committee of Manipal College of Dental Sciences. As the methodology was approved, patients reporting to the outpatient department of Periodontics Department, complaining of cervical dentinal hypersensitivity were examined. To participate in the trial, patients were required to present a minimal of two teeth with dentinal hypersensitivity and a VAS reading of ≥3. Individuals that presented as probable etiological factors for dentine hypersensitivity, para-functional habits, gastric and/or emotional diseases, or frequent ingestion of acidic food. Subjects whose test teeth had evidence of carious lesions, defective restorations, facets of attrition, premature contact, cracked enamel, or any other factor that could be responsible for sensitivity were also excluded from the study. The nature and objectives of the trial, as well as the possible discomfort and risks, were fully explained and all participants signed the appropriate, approved informed consent documents.

Dentine hypersensitivity was assessed by an evaporative stimulus (ES) and thermal stimulus (TS). A cold air-blast from a three-way dental syringe was directed to the exposed area for 5 s under relative isolation at a distance of approximately 2 cm and cold stimuli (ice stick contacting the tooth surface). The subjects placed a mark on a 100 mm long line on the VAS that was labeled from “no pain ” (0) to “intolerable pain ” (10). At each evaluation, two stimuli were elicited. ES was applied before the TS.

Vitality testing

Every tooth included in the study was evaluated for vitality to rule out pulpal pathology. Cold test, heat test, and electric pulp testing were done.

After the baseline pain assessment in each patient, the teeth were randomly assigned to group 1 (only bifluoride 12) or group 2 (bifluoride + laser). The randomization was done by a coin toss method. The treatment was performed by one operator and the pain was assessed by another one to avoid bias.

For teeth treated by NaF varnish (Duraphat), two-three coats were applied on the same day. The varnish was applied with a pellet at cervical region of buccal surfaces. The patients were instructed not to eat for 1 h following varnish application and to reinitiate tooth brushing solely after 12 h, thus enhancing the interaction of fluoride with tooth structure.

The sensitive teeth were irradiated on contact mode with the following parameters: 0.4 W output power and 4 J cm 2 energy density. Laser beam was directed perpendicularly to the tooth surface at three points: Mesiobuccal, buccal, and one distobuccal. Each area was irradiated for 10 s (total of 30 s per tooth).

The effectiveness of both therapies was assessed (by scoring patients' response following the predefined criteria) at three examination periods: immediately after the first application of the desensitizing agent, 15, 30, and 60 days after the first application.

   Results Top

A total of 50 teeth from 14 patients meeting the inclusion criteria were selected for the study. Out of 14 patients, 4 were females and 10 were males.

Although the mechanism of action for fluoride varnish and the laser is different, both the treatment modalities were effective in the management of dentinal hypersensitivity. [Graph 1] shows the efficacy of both groups in dentinal hypersensitivity.

[Graph 2] shows the efficacy of fluoride application in the management of dentinal hypersensitivity. The efficacy gradually decreased from 60% immediately after 15 min to 42% approximately after 30 days and 30% after 60 days. This gradual reduction of efficacy of fluoride varnish may be due to a single application.

[Graph 3] shows the efficacy of combined application of diode laser and fluoride. At any point of observation, the efficacy rate is higher than application of fluoride alone as shown in [Graph 1]. At 15 days, the efficacy of fluoride alone was 54.89% for ES and 54.66% for TS.

[Table 1] shows the comparison of two groups: bifluoride alone and the other is the combination of diode laser and bifluoride. Statistical significance was seen in TS at 15 days, both ES and TS at 30 days and TS at 60 days. The combined therapy was superior to use of fluoride alone.
Table 1: Comparison of the 2 techniques, flouride and flouride with diode Laser

Click here to view

   Discussion Top

A possible elimination of painful symptomatology resulting from the dentine hypersensitivity mechanism, seems to be directly related to the interruption of stimuli transmission to the nerve endings of odontoblast processes by reducing the fluid movement inside the dentinal canalicules, through the narrowing or occlusion of tubules openings.[3] Although low-level lasers and fluoride varnishes present distinct modes of action, in the present study both treatments provided a significant overall relief in dentine hypersensitivity.

The effectiveness of NaF varnish can be attributed to the formation of CaF2 crystals as NaF reacts with the Ca ++ ions. The patency of sensitive dentine interferes with the action of therapeutic tubule occlusive agents and demands a longer treatment, as the number and width of dentinal tubules in hypersensitive-exposed areas have been shown to be higher than in normal dentine.[7] The depressed transmission of nerve impulses is the mechanism of action of diode lasers in hypersensitivity. Moreover, besides the immediate analgesic effect, the laser therapy-if used within the correct parameters-may stimulate the normal physiological cellular functions. The laser would stimulate the production of sclerotic dentin, thus promoting the internal obliteration of dentinal tubules.[8]

Reduction in sensitivity to thermal and tactile stimuli has been widely reported using and He-Ne and GaAlAs lasers.[9],[10] Although low-level lasers and fluoride varnishes present distinct modes of action, in the present study both treatments provided a significant overall relief in dentine hypersensitivity.

In the fluoride varnish group, the immediate efficacy was 58.86%. The combined action of diode laser and fluoride varnish had efficacy of 63.35% of ES and 65.86% of TS. Better results were obtained in the combined group after 15 min. The similar results were obtained by Kumar and Mehta [11] in which the laser + fluoride varnish had 62% efficacy. Lan and Liu [12] evaluated the combined effect of semiconductor diode laser with Duraphat. They concluded that the combined use of laser with topical fluoride application enhanced treatment effectiveness by more than 20%.

The laser and bifluoride group when compared to only bifluoride group had better reduction of TS after 15 days, both ES and TS after 30 days and TS after 60 days. These findings were similar to Corona et al.[10] in which the combined effect of Nd: YAG laser were superior to fluoride alone as fluoride varnish is subjected to removal during tooth brushing.

If fluoride varnish is used alone in the management of dentinal hypersensitivity, the efficacy of it reduces from 15 days to 60 days as it is subjected to removal during tooth brushing. Similar findings were present in a study conducted by Corona et al.[10] in which the efficacy of 5% NaF decreased from 15 days to 30 days. From the conclusion of these studies, the following conclusion can be drawn that is fluoride varnish application has to be repeated at regular intervals.

Histologically, Corona et al.[10] concluded that the combined effect of GaAlAs laser and fluoride varnish lead to 90% tubule closure as compared with individual application. The similar findings can be drawn from our study in which statistical significant differences were found in the combined group at 15 days for TS, ES, and TS at 30 days and TS at 60 days. Ipci et al.[13] concluded that the combined group of CO2 + NaF, Er: YAG + NaF had better effects than laser or fluoride alone.

The crystal size of fluoride varnish is small (about 0-0.05 μm), a single application of NaF would not be effective in narrowing the diameter of tubules.[5] This can be evident from the findings of our study that the immediate efficacy of fluoride varnish was 60% and it reduced to 30% after a follow up period of 60 days. Similar findings were noted by Kara and Orbak.[14]

The immediate low-level laser effect on dentinal hypersensitivity relies mainly upon induced changes in the neural transmission networks within the dental pulp (depressed nerve transmission) rather than alterations in the exposed dentine surface as observed in other treatment modalities.[15] Stimulation of odontoblasts, production of reparatory irregular dentin and obliteration of dentinal tubules provoked by laser are reasons for the prolonged suppression of pain in dentinal hypersensitivity.[16]

   References Top

Addy M. Etiology and clinical implications of dentine hypersensitivity. Dent Clin North Am 1990;34:503-14.  Back to cited text no. 1
Holland GR, Narhi MN, Addy M, Gangarosa L, Orchardson R. Guidelines for the design and conduct of clinical trials on dentine hypersensitivity. J Clin Periodontol 1997;24:808-13.  Back to cited text no. 2
Brannstrom MA. A hydrodynamic mechanism in the transmission of pain producing stimuli through the dentine. In: Anderson DJ, editor. Sensory Mechanism in Dentine. Oxford: Pergamon Press; 1962. p. 73-9.  Back to cited text no. 3
Gaffar A. Treating hypersensitivity with fluoride varnish. Compend Contin Educ Dent 1999;20 1 Suppl: 27-33.  Back to cited text no. 4
Lan WH, Liu HC, Lin CP. The combined occluding effect of sodium fluoride varnish and Nd: YAG laser irradiation on human dentinal tubules. J Endod 1999;25:424-6.  Back to cited text no. 5
Ladalardo TC, Pinheiro A, Campos RA, Brugnera Júnior A, Zanin F, Albernaz PL, et al. Laser therapy in the treatment of dentine hypersensitivity. Braz Dent J 2004;15:144-50.  Back to cited text no. 6
Absi EG, Addy M, Adams D. Dentine hypersensitivity. A study of the patency of dentinal tubules in sensitive and non-sensitive cervical dentine. J Clin Periodontol 1987;14:280-4.  Back to cited text no. 7
Gerschman JA, Ruben J, Gebart-Eaglemont J. Low level laser therapy for dentinal tooth hypersensitivity. Aust Dent J 1994;39:353-7.  Back to cited text no. 8
Kimura Y, Wilder-Smith P, Yonaga K, Matsumoto K. Treatment of dentine hypersensitivity by lasers: A review. J Clin Periodontol 2000;27:715-21.  Back to cited text no. 9
Corona SA, Nascimento TN, Catirse AB, Lizarelli RF, Dinelli W, Palma-Dibb RG. Clinical evaluation of low-level laser therapy and fluoride varnish for treating cervical dentinal hypersensitivity. J Oral Rehabil 2003;30:1183-9.  Back to cited text no. 10
Kumar NG, Mehta DS. Short-term assessment of the Nd: YAG laser with and without sodium fluoride varnish in the treatment of dentin hypersensitivity-A clinical and scanning electron microscopy study. J Periodontol 2005;76:1140-7.  Back to cited text no. 11
Lan WH, Liu HC. Sealing of human dentinal tubules by Nd: YAG laser. J Clin Laser Med Surg 1995;13:329.  Back to cited text no. 12
Ipci SD, Cakar G, Kuru B, Yilmaz S. Clinical evaluation of lasers and sodium fluoride gel in the treatment of dentine hypersensitivity. Photomed Laser Surg 2009;27:85-91.  Back to cited text no. 13
Kara C, Orbak R. Comparative evaluation of Nd: YAG laser and fluoride varnish for the treatment of dentinal hypersensitivity. J Endod 2009;35:971-4.  Back to cited text no. 14
Walsh LJ. The current status of low level laser therapy in dentistry. Part 2. Hard tissue applications. Aust Dent J 1997;42:302-6.  Back to cited text no. 15
Sicilia A, Cuesta-Frechoso S, Suárez A, Angulo J, Pordomingo A, De Juan P. Immediate efficacy of diode laser application in the treatment of dentine hypersensitivity in periodontal maintenance patients: A randomized clinical trial. J Clin Periodontol 2009;36:650-60.  Back to cited text no. 16


  [Table 1]

This article has been cited by
1 Comparison of the efficacy of 940-nm diode laser, Gluma, and 5% sodium fluoride varnish in dentinal tubule occlusion
Yasaman Vazirizadeh, Arash Azizi, Shirin Lawaf
Lasers in Dental Science. 2022;
[Pubmed] | [DOI]
2 Evaluation of the efficacy of sodium fluoride varnish, dentine bonding agent and diode laser in the treatment of dentine hypersensitivity: A clinical and scanning electron microscopic study
Himanshu Aeran, Amrinder Singh Tuli, Supriya Elizabeth Paul
International Journal of Oral Health Dentistry. 2022; 8(2): 170
[Pubmed] | [DOI]
3 Comparative evaluation of the efficacy of light amplification by the stimulated emission of radiation, desensitizing agents, and their combined effect on dentinal hypersensitivity in cuspids and bicuspids In Vivo Study
Shazia Siddiqui, Mohsin Khan, Ramesh Chandra, Supratim Tripathi, Jyoti Jain, UrvashiOjha Tiwari
Journal of Conservative Dentistry. 2022; 25(4): 363
[Pubmed] | [DOI]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
   Subjects and Methods
    Article Tables

 Article Access Statistics
    PDF Downloaded657    
    Comments [Add]    
    Cited by others 3    

Recommend this journal