Available online 2 December 2023, 104798

Author links open overlay panel, , , , , ABSTRACTObjective

To investigate the effect of toothbrush head configuration and dentifrice slurry abrasivity on the development of simulated non-carious cervical lesions (NCCLs) in vitro.

Methods

Extracted premolars were randomly allocated into 15 groups (n=16) generated by the association between toothbrush head configuration (flat-trimmed, rippled, cross-angled/multilevel/rubbers added, cross-angled/multilevel/flex head, feathered) and dentifrice slurry abrasivity (low/medium/high). Teeth were mounted on acrylic blocks and had their roots partially covered with acrylic resin, leaving 2-mm root surfaces exposed. Toothbrushing was performed for 35,000 and 65,000 double-strokes. Specimens were analyzed using non-contact profilometry for dental volume loss (mm3) and lesion morphology. Data was analyzed using ANOVA with pairwise comparisons and Kruskal-Wallis tests.

Results

The two-way interaction between toothbrush head configuration and slurry abrasivity was significant (p=0.02). At 35,000 strokes, the flat-trimmed and cross-angled/multilevel/rubbers added toothbrushes caused the highest loss, when associated to the high-abrasive slurry (p<0.05); whereas cross-angled/multilevel/flex head showed the least loss, when associated to the low-abrasive (p<0.05). At 65,000, more dental loss was observed for all toothbrushes when associated to the high-abrasive slurry, with flat-trimmed causing the highest loss (p<0.05). Lower dental loss rates were observed for cross-angled/multilevel/flex head associated to the low-abrasive slurry when compared to the other toothbrushes (p<0.05), except to feathered (p=0.14) and rippled (p=0.08). Flat lesions (mean internal angle ± standard-deviation: 146.2°±16.8) were mainly associated with low-abrasive slurry, while wedge-shaped lesions (85.8°±18.8) were more frequent with medium- and high-abrasive slurries.

Conclusion

The development, progression and morphology of simulated NCCLs were modulated by both toothbrush head configuration and dentifrice abrasivity.

CLINICAL SIGNIFICANCE

Dental professionals should consider both the type of toothbrush and dentifrice abrasivity in the management plan of patients at risk of developing NCCLs.

Section snippetsINTRODUCTION

Non-carious cervical lesions (NCCLs) result from tooth structure loss at the cemento-enamel junction caused by different wear processes unrelated to dental caries [1,2]. Their prevalence in individuals aged 18 years or older is high at 68.5%, with varying degrees of severity [3]. Besides the overall increase on individuals’ longevity, developments in preventive dentistry concepts and the widespread availability of preventive services have contributed to oral health improvements. As result,

Experimental Design

The study followed a randomized complete block design and examined three experimental factors: five toothbrush head configurations (Figure S1), three simulated dentifrice slurry abrasive levels: low, medium, and high, as well as three periods of toothbrushing cycles: (0) baseline before toothbrushing, 35,000, and 65,000 brushing cycles. Each brushing cycle consisted of a back-and-forth brushing stroke. A factorial arrangement of toothbrush head configuration and dentifrice slurries was used to

RESULTS

A significant interaction among the experimental factors (toothbrush type × abrasive level × brushing cycles) was observed (p = 0.05). Brushing cycles had a significant impact on dental volume loss (p < 0.01), with 65,000 brushing cycles causing significantly greater loss than 35,000, for all toothbrush and abrasive slurries combinations. In addition to brushing cycles, dentifrice slurry abrasivity had a significant impact on dental volume loss (p < 0.01).

DISCUSSION

The findings of this study showed that toothbrush head configuration was relevant to dental loss. Overall, the least detrimental combinations were the cross-angled/multilevel/flex head toothbrush with low-abrasive slurry, and the feathered toothbrush with the medium- and high-abrasivity slurries. These results corroborate those of a previous similar study by Turssi et al. (2019) and show the importance of the toothbrush head configuration in NCCL development [11]. Unlike the feathered, with its

CONCLUSION

The findings of this in vitro study showed that the combination between toothbrush head configuration and abrasive level of dentifrice slurry modulated the development of simulated NCCLs. Strategies for the prevention of NCCL development may focus on the use of low abrasive dentifrices in association with specific less abrasive (cross-angled/multilevel/flex head, feathered and rippled) toothbrushes.

FUNDING

Dr. Alzahrani received a scholarship from the Ministry of Higher Education and Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia. This project was supported by the Oral Health Research Institute, Indiana University School of Dentistry.

CRediT authorship contribution statement

Lina Alzahrani: Conceptualization, Data curation, Investigation, Methodology, Writing – original draft. Giovanna C. Denucci: . Frank Lippert: Conceptualization, Investigation, Writing – review & editing. Laila Al Dehailan: Conceptualization, Writing – review & editing. Surya S. Bhamidipalli: . Anderson T. Hara: .

Declaration of Competing Interest

We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome.

ACKNOWLEDGEMENTS

This research was part of Dr. Alzahrani's thesis submitted in partial fulfillment of the MSD degree in Cariology and Operative Dentistry at Indiana University School of Dentistry.

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