Evaluation of PAP-Based Herbal Teeth Whitening Strips: Efficacy and Enamel Safety Assessment

Abstract

This study evaluated the efficacy and enamel safety of a peroxide-free, PAP-based herbal whitening strip containing papain, bromelain, and Glycyrrhiza glabra extract. Twenty removed human premolars were artificially stained and treated for 14 days. We employed spectrophotometric ?E analysis to see how well the medicine worked and enamel microhardness and surface roughness assessments to see how safe it was. The PAP-herbal system produced clinically significant whitening (?E = 6.5 ± 0.8; p < 0.05), accompanied by a minor reduction in enamel hardness and a moderate increase in surface roughness. These results show that PAP-herbal systems are good and safer than peroxide-based whitening treatments

Keywords

Introduction

 

 

Figure 1 Whitening Efficacy (ΔE Analysis)

 

 

Figure 2 Enamel Microhardness

 

 

Figure 3 Surface Roughness

DISCUSSION

1. Whitening Mechanism Analysis

The significant ΔE increase confirms effective oxidation of chromogenic molecules. Unlike hydrogen peroxide, PAP acts through epoxidation and oxygen transfer reactions rather than aggressive free radical diffusion. Proteolytic enzymes (papain and bromelain) likely contributed to degradation of protein-bound stains on the acquired pellicle layer, enhancing overall whitening efficiency.

The observed cumulative increase in ΔE suggests sustained release and effective contact time provided by strip delivery technology.

2. Enamel Safety Evaluation

Microhardness reduction was minimal (2.2%) and statistically insignificant, suggesting that PAP does not cause meaningful mineral loss. Surface roughness increase was mild and likely due to superficial organic matrix interaction rather than true erosive demineralization. These findings support the hypothesis that PAP-based systems provide whitening efficacy with improved safety profile compared to peroxide-based systems.

3. Clinical Relevance

A whitening system is considered clinically successful when:

• ΔE ≥ 3.3
• No significant microhardness reduction
• No visible enamel erosion

All criteria were satisfied in this study.

4. Scientific and Societal Implications

Scientific

• Supports peroxide-free oxidation chemistry
• Demonstrates enzyme-assisted whitening synergy
• Provides formulation basis for safer cosmetic oral products

Societal

• Addresses growing consumer demand for herbal and peroxide-free systems
• Potential reduction in tooth sensitivity
• Expands over-the-counter cosmetic dental innovation

Limitations

• In vitro conditions do not simulate saliva buffering
• No SEM analysis performed
• Long-term enamel exposure not evaluated

CONCLUSION

PAP-based herbal whitening strips demonstrated clinically significant stain reduction (ΔE = 6.5) with minimal enamel microhardness reduction and mild surface roughness increase. The system appears to be an effective and safer alternative to peroxide-based whitening formulations.

The hypothesis is accepted.

REFERENCES

1. Watts A, Addy M. Tooth discoloration and staining: a review of the literature. Br Dent J. 2001;190(6):309–316.
2. Joiner A. Tooth colour: a review of the literature. J Dent. 2004;32(Suppl 1):3–12.
3. Carey CM. Tooth whitening: what we now know. J Evid Based Dent Pract. 2014;14(Suppl):70–76.
4. Attin T, Hannig C, Wiegand A, Attin R. Effect of bleaching on restorative materials and enamel. Dent Mater. 2004;20(9):852–861.
5. Basting RT, Rodrigues AL Jr, Serra MC. The effect of 10% carbamide peroxide bleaching on enamel microhardness. Oper Dent. 2001;26(6):531–539.
6. Kwon SR, Wertz PW. Review of the mechanism of tooth whitening. J Esthet Restor Dent. 2015;27(5):240–257.
7. Alqahtani MQ. Tooth bleaching procedures and their controversial effects: a literature review. Saudi Dent J. 2014;26(2):33–46.
8. Pithon MM, dos Santos RL, Ruellas AC, et al. Effectiveness of papain gel in the removal of stains. Angle Orthod. 2010;80(4):761–765.
9. Messier C, Epifano F, Genovese S, Grenier D. Licorice and its potential beneficial effects in common oral diseases. Oral Dis. 2012;18(1):32–39.
10. Paravina RD, Ghinea R, Herrera LJ, et al. Color difference thresholds in dentistry. J Esthet Restor Dent. 2015;27(S1):S1–S9.