Comparative Evaluation of Effect of Nano-hydroxyapatite and 8% Arginine Containing Toothpastes in Managing Dentin Hypersensitivity: Double Blind Randomized Clinical Trial

Published In: Acta Medica (Hradec Králové)
Publication Year: 2017 (online 2018)

Study Design

This double-blind, randomized clinical trial compared the effectiveness of two active toothpastes — one containing nano-hydroxyapatite (nHA) and another with 8% arginine — in relieving dentin hypersensitivity (DH).

Sensitivity relief was assessed objectively using a digital pulp tester that measured the electrical current (amperage) needed to elicit a standardized “pre-pain” response (VAS = 2). Measurements were taken at 5 minutes, 1 week, and 4 weeks after starting treatment.

Funding Sources

The article did not report any funding sources or conflicts of interest.

PICO Framework - what was studied and how?

Population:
Adults with clinically confirmed dentin hypersensitivity who scored above 2 on a visual analog scale (VAS) after both air-blast and tactile tests. One sensitive tooth per participant was included.

Intervention:
Topical application and daily use of a toothpaste containing nano-hydroxyapatite (nHA).

Comparison:
Toothpaste containing 8% arginine, used following the same instructions and schedule.

Outcomes:
Reduction in hypersensitivity measured as the increase in electrical current (amperage) required to elicit a VAS = 2 response. A higher amperage indicates less sensitivity.

In Paragraph Form:
This randomized clinical trial evaluated adults experiencing dentin hypersensitivity to determine whether toothpaste with nano-hydroxyapatite or 8% arginine provided greater relief. Using a digital pulp tester, researchers measured the current needed to cause mild discomfort at baseline and again at 5 minutes, 1 week, and 4 weeks. The study aimed to identify which formulation most effectively reduced hypersensitivity over time.

Inclusion and Exclusion Criteria

Inclusion Criteria:

• Adults with dentin hypersensitivity confirmed by both air-blast and tactile tests.

• VAS score greater than 2.

• One sensitive tooth per participant selected for testing.

• Participants provided informed consent.

Exclusion Criteria:

• Individuals not meeting inclusion criteria (29 excluded).

• Participants who declined to participate (6 excluded).

• The article did not list additional medical or dental exclusion details.

Demographics and Study Design

• Total Participants: 60 (30 per group).

• Randomization: 1:1 block randomization.

• Blinding: Both investigators and participants were blinded to product identity.

• Dropouts: None reported.

Baseline Characteristics:

Home-use Instructions:
Participants applied approximately 1 cm of toothpaste directly to the sensitive area for 1 minute, followed by 2 minutes of brushing, twice daily for 4 weeks. No other oral hygiene products were permitted during the study period.

Primary Outcome Variables and Results

Outcome:
Change in electrical current (amperage) needed to elicit a “pre-pain” VAS = 2 response. A higher amperage indicates lower sensitivity.

Results:
Both toothpastes provided significant and immediate desensitizing effects at 5 minutes, with continued improvement at 1 and 4 weeks (p < 0.001 for all time points within groups).

Between-group differences:
No statistically significant difference was observed between nano-hydroxyapatite and arginine toothpastes at any time point.

Descriptive Mean Amperage Values:

• Arginine group: 6.27 → 8.23 → 9.87 → 11.27

• nHA group: 6.23 → 8.27 → 9.93 → 11.53

Key Statistical Findings:

• Both groups improved significantly over time (p < 0.001).

• No significant inter-group difference at any evaluation point (p > 0.05).

Conclusions

Both nano-hydroxyapatite and 8% arginine toothpastes provided immediate and sustained relief from dentin hypersensitivity after 5 minutes, 1 week, and 4 weeks of use.

There was no statistically significant difference in effectiveness between the two, suggesting that both active ingredients can offer comparable desensitizing benefits for patients experiencing dentin hypersensitivity.

Discussion: Strengths and Limitations

Strengths:

• Randomized, double-blind design minimized bias.

• Use of an objective measurement (digital pulp tester) ensured reproducibility.

• Immediate and follow-up data points provided insight into both short-term and long-term relief.

Limitations:

• Lack of a placebo or control group limited comparison against baseline improvement due to brushing alone.

• Electrical measurement precision could vary with probe positioning; future studies should employ positioning jigs.

• Study assessed only one sensitive tooth per participant, limiting generalization to multiple sites.

Clinical Significance:
Both formulations demonstrated reliable desensitizing effects, providing dental professionals and patients with viable non-fluoride options for managing dentin hypersensitivity.

Citation

Anand S, Rejula F, Sam JVG, Christaline R, Nair MG, Dinakaran S. Comparative Evaluation of Effect of Nano-hydroxyapatite and 8% Arginine Containing Toothpastes in Managing Dentin Hypersensitivity: Double Blind Randomized Clinical Trial. Acta Medica (Hradec Králové). 2017;60(3):114–119.
PubMed: https://pubmed.ncbi.nlm.nih.gov

Simple Chart: Dentin Hypersensitivity Reduction (Higher = Less Sensitivity)