RESEARCH PROPOSAL FOR CLINICAL TRAIL REGISTRY

Title of the project: Comparison of 980nm and 1064-nm diode LASERs in treating dentinal

Hypersensitivity

Faculty of Dental Sciences

Department: Periodontology

Principle Investigator

Dr. Akshatha Raj, Assistant Professor, Dept. of Periodontology

Investigators

Dr. Rohit Prasad, Associate Professor, Dept. of Periodontology

Dr. Bhavya B, Associate Professor, Dept. of Periodontology

Rationale

Dentinal hypersensitivity is defined as, “a short sharp pain arising from exposed dentin in response to stimuli, typically thermal, evaporative, tactile, osmotic, or chemical and which cannot be ascribed to any other dental defect or pathology” (Gilliam DG et.al.,2006). It is a painful response of the tooth to different stimuli such as ‘brushing, acid diets, and thermal changes’ and is one of the frequently encountered symptoms in the dental office (Anirudh B acharya et al,2022). It is described as a multifactorial case of multiple etiologies and risk factors, e.g., tooth wear and gingival recession (West et al,2014). According to Brannstrom’s hydrodynamics theory, when a stimulus is applied to dentine, the fluid inside the tubule will get displaced inwardly and outwardly, causing deformation of the nerve endings at the pulp-dentine interface, and transmitting a painful sensation leading to Dentinal hypersensitivity (Dowell et al,1983). A proper treatment modality should not irritate the tooth pulp and should not cause pain when it is applied and it also should be easy to apply, be cost-effective, act fast, have long-lasting effects and be resistant to the challenges in the oral cavity. In addition, it should not irritate the oral cavity soft tissues and should not stain teeth; however, the majority of the treatment modalities lack these criteria (Grossman et al,1935). Different techniques have been considered for the treatment of dentinal hypersensitivity, the most common of which is the use of local home remedies and methods such as the use of adhesives, varnishes, bonding agents, periodontal grafts, and restorative procedures, which yield variable results (Gbadebo et al,2016). A well-known mechanism for treating the same is obliterating or narrowing the dentinal tubules, by inducing hydroxyapatite crystals using LASER heat (Saluja et al,2016).

Recently, irradiation with low-output LASERs on affected teeth has been proposed due to their significant anti-inflammatory actions (Bjordal et al,2003). Diode LASER works by generating continuous waves without overheating (Morita et al,1993).

Need for the study: Dentinal hypersensitivity is one of the most common chief complaint of patients heard in dental practice affecting up to 57% of patients annually (Walters,2005). The basic principles for the prevention of dentinal hypersensitivity are blocking the dentinal tubules or chemically blocking the pulpal nerve (Dam et al,2022). The laser-assisted treatment of dentinal hypersensitivity is a promising tool to solve immediate and long-term pain. LASERs such as Nd YAG, diode with various wavelength have been used for its management. Recently, 1064nm diode laser has been used to treat dentinal hypersensitivity. To the best of our knowledge, there is a paucity in the studies done to compare the efficacy of 980nm and 1064nm diode LASER in the treatment of dentinal hypersensitivity but, there are no studies conducted to assess both the in-vivo and in-vitro characteristics of two different wavelengths.

Research Question: Is 1064nm diode LASER more efficient than 980nm wavelength for the treatment of dentinal hypersensitivity?

Null Hypothesis: There is no difference between 1064nm and 980nm wavelength LASERs for the treatment of dentinal hypersensitivity.

Clear Research Aim and Objectives:

Aim: To compare and assess the effects of 980 nm and 1064 nm diode LASERs on dentinal hypersensitivity.

Objectives:

1.     To study the invitro characteristics in morphological alterations of the dentin surface and odontoblasts after irradiating with 980nm and 1064nm diode LASERs.

2.     To assess the effects of 980 nm and 1064 nm diode LASERs on patients with dentinal hypersensitivity.

3.     To compare the effects of 980 and 1064 nm diode LASERs on patients with dentinal hypersensitivity.

  Methodology

Methodology for objective 1:

Study design: In vitro study

Study period: 1 week

Resources required: 980 nm and 1064 nm diode LASERs, Scanning Electron Microscope (SEM)

Two extracted human teeth will be selected to prepare dentin discs. Crowns with caries, restorations, or fractures will be discarded. Each dentin disc will be divided into four areas and will be irradiated by 980-nm diode LASER and 1064 nm diode LASER. The morphological alterations of the dentin surfaces and odontoblasts will be examined with scanning electron microscopy (SEM), and the morphological alterations of the dental pulp tissue irradiated by LASER will be observed with an upright microscope.

Methodology for objectives 2 and 3:

Study design: Randomized parallel Trial

Study setting: Department of Periodontology, FDS, RUAS

Study period: 3 months

Sample Size Determination:

Analysis:   A priori: Compute required sample size

The sample size for the present study was estimated using GPower software (latest ver. 3.1.9.7;

Heinrich-Heine-Universi-ta t Du ̈sseldorf, Du ̈sseldorf, Germany). The sample size estimation was

performed at 5% alpha error (α = 0.05), with an effect size of 1.25 [Based on the findings from the previous literature by Narges Naghsh et al, 2021 for the mean difference in the VAS scores b/w 2 groups] with 95% Confidence Interval & the study power at 80%, demonstrated that a minimum of 24 samples will be needed for the present study. Anticipating 20% attrition during the follow-up period, the sample size will be inflated to 30 samples. So, each study group will consist of 15 samples.

POWER ANALYSIS CURVE

Inclusion criteria:

1.     Teeth with dentinal hypersensitivity

2.     Selected teeth without calculus and plaque

3.     Undergo a scaling procedure before the study (if necessary)

4.     Exhibit sensitivity to the cold test

Exclusion criteria:

1.     Pregnant women

2.     Active Periodontal disease

3.     Crown fractures

4.     Cracks

5.     Caries or restorations

6.     Existing trauma from occlusion

7.     Occlusal interferences

8.     Patients having taken analgesics during the 72 hours period before LASER therapy

9.     Patients having used desensitizing toothpastes during the 3-month period

Resources required: 980 nm and 1064 nm diode LASERs

Methodology for objective 2:

To assess the effects of 980 nm and 1064 nm diode LASERs on patients with dentinal hypersensitivity by measuring VAS scores 15 min, 1 week, 1 month, and 2 months after the intervention in each group.

Methodology for objective 3:

To compare the effects of 980 nm and 1064 nm diode LASERs on patients with dentinal hypersensitivity by evaluating the mean VAS scores at 15 min, 1 week, 1 month, and 2 months after the intervention in both the groups.

Plan for Statistical Analysis of the Study:

Statistical Package for Social Sciences [SPSS] for Windows Version 22.0 Released 2013. Armonk, NY: IBM Corp. will be used to perform statistical analyses.

Descriptive Statistics:

Descriptive analysis of all the explanatory and outcome parameters will be done using mean and standard deviation for quantitative variables, frequency and proportions for categorical variables.

Inferential Statistics:

Independent Student t Test / Mann Whitney Test [Based on Data Distribution] will be used to compare the mean VAS scores between 2 study groups at different time intervals.

Repeated Measures of ANOVA Test followed by Bonferroni’s post hoc test / Friedman’s test followed by Wilcoxon signed Rank post hoc test will be used to compare the mean VAS scores between different time intervals in each group.

The level of significance will be set at P<0.05.

And any other relevant test, if found appropriate during the time of data analysis will be dealt accordingly.

References

1.     Bjordal JM, Couppé C, Chow RT, Tunér J, Ljunggren EA. A systematic review of low level laser therapy with location-specific doses for pain from chronic joint disorders. Australian journal of physiotherapy. 2003 Jan 1;49(2).

2.     Dam, V.V., Trinh, H.A., Dung, D.T. and Hai, T.D., 2022. Advances in the Management of Dentin Hypersensitivity: An Updated Review. The Open Dentistry Journal, 16(1).

3.     Doppalapudi, H., Kancharla, A.K., Nandigam, A.R., Tasneem, M.S., Gummaluri, S.S. and Dey, S., 2023. Comparative evaluation of diode laser alone and in combination with desensitizing toothpaste in occlusion of dentinal tubules-A SEM study. Journal of Oral Biology and Craniofacial Research.

4.     Dowell, P. and Addy, M., 1983. Dentine hypersensitivity‐A review: Aetiology, symptoms and theories of pain production. Journal of clinical periodontology, 10(4).

5.     Femiano, F., Femiano, L., Nucci, L., Grassia, V., Scotti, N. and Femiano, R., 2022. Evaluation of the effectiveness on dentin hypersensitivity of sodium fluoride and a new desensitizing agent, used alone or in combination with a diode laser: A clinical study. Applied Sciences, 12(12).

6.     Gbadebo, S.O., Lawal, F.B. and Arowojolu, M.O., 2016. Dentine hypersensitivity: Real or imagined. Nigerian Journal of Medicine, 25(2).

7.     Grossman, L.I., 1935. A systematic method for the treatment of hypersensitive dentin. The Journal of the American Dental Association (1922), 22(4).

8.     Liu, Y., Gao, J., Gao, Y., Shuaimei, X.U., Zhan, X. and Wu, B., 2013. In vitro study of dentin hypersensitivity treated by 980-nm diode laser. Journal of lasers in medical sciences, 4(3).

9.     Morita, H., Kohno, J., Tanaka, S., Kitano, Y. and Sagami, S., 1993. Clinical application of GaAlAs 830 nm diode laser for atopic dermatitis. Laser therapy, 5(2).

10.  Naghsh, N., Kachuie, M., Kachuie, M. and Birang, R., 2020. Evaluation of the effects of 660-nm and 810-nm low-level diode lasers on the treatment of dentin hypersensitivity. Journal of Lasers in Medical Sciences, 11(2).

11.  Naghsh, N., Kachuie, M., Bijari, M. and Birang, R., 2022. Evaluation of the effects of 980 and 810-nm high-level diode lasers in treating dentin hypersensitivity: A double-blinded randomized clinical trial. Dental Research Journal, 19(1).

12. Pereira, J.C., Segala, A.D. and Gillam, D.G., 2005. Effect of desensitizing agents on the hydraulic conductance of human dentin subjected to different surface pre-treatments-an in vitro study. Dental Materials,