Effects of Hydroxyapatite-Containing Toothpastes on Some Caries-Related Variables: A Randomised Clinical Trial

Effects of Hydroxyapatite-Containing Toothpastes on Some Caries-Related Variables: A Randomised Clinical Trial

Effects of Hydroxyapatite-Containing Toothpastes on Some Caries-Related Variables: A Randomised Clinical Trial

Published In: International Dental Journal
Publication Year: 2024

Study Design

This was a randomised, triple-blind clinical trial conducted over 24 months, evaluating the effects of hydroxyapatite-containing toothpaste on oral biofilm acidogenicity and cariogenic bacteria in children.

Funding Sources

  • Academic: Department of Surgery, Microsurgery and Medicine Sciences—School of Dentistry, University of Sassari, Italy

  • Industry: Curaspet S.p.A. (Milan, Italy)
    Note: Funders had no role in the study design, data collection, or publication decisions.

PICO Framework – what was studied and how?

Population:
Children aged 4–7 years attending schools in the Sassari region of Italy.

Intervention:
Toothpaste containing fluoride-substituted hydroxyapatite (HAF1000 and HAF1450), enhanced with magnesium, strontium, and carbonate-substituted hydroxyapatite in a chitosan matrix.

Comparison:
Traditional sodium monofluorophosphate fluoridated toothpastes (F1000 and F1450).

Outcomes:

  • Changes in plaque pH following sucrose challenge

  • Shifts in cariogenic bacterial composition

  • Caries development assessed using the ICDAS system

In Paragraph Form:
This study investigated whether fluoride-substituted hydroxyapatite toothpaste could more effectively modulate dental plaque pH and reduce cariogenic bacteria in young children compared to standard fluoridated toothpaste. Outcomes were measured by plaque acidogenicity, microbiological composition, and caries progression.

Inclusion and Exclusion Criteria

Inclusion Criteria:

  • Children aged 4–7 years

  • Enrolled in selected schools in Sassari, Italy

  • Parental/caregiver informed consent provided

Exclusion Criteria:

  • Use of other fluoridated products (e.g., salt, mouthwash, gels) during study

  • Non-adherence to assigned toothpaste for more than 1 week

Demographics and Study Design

Total Sample Size: 610 children
Randomly allocated into four groups:

Group Sample Size
HAF1000 153
F1000 151
HAF1450 152
F1450 154

  • Children brushed 3 times/day: once supervised at school, twice at home.

  • Follow-up exams conducted at 12 and 24 months.

  • COVID-19 delays affected some 24-month follow-ups.

Primary Outcome Variables and Results

Outcome 1: Plaque pH after Sucrose Challenge

Hydroxyapatite groups showed the highest improvement in minimum pH and greatest reduction in acid production.

Group Min Plaque pH (Baseline) Min Plaque pH (2-Year) Max pH Drop (Baseline) Max pH Drop (2-Year)
HAF1000 5.32 ± 0.41 5.72 ± 0.22 1.17 ± 0.42 1.00 ± 0.34
F1000 5.34 ± 0.50 5.49 ± 0.32 1.20 ± 0.46 1.06 ± 0.33
HAF1450 5.35 ± 0.44 5.66 ± 0.36 1.18 ± 0.56 1.05 ± 0.11
F1450 5.36 ± 0.37 5.51 ± 0.38 1.19 ± 0.51 1.01 ± 0.34

Statistical Significance:

  • p < 0.05 for improved minimum pH in HAF vs. F groups

  • p < 0.05 for reduced acid production in HAF groups only

Outcome 2: Bacterial Composition of Plaque (Key Findings)

At 24 months, HAF toothpaste groups had significantly lower levels of cariogenic bacteria compared to fluoride toothpaste groups.

Bacteria HAF1000 (2-Year) F1000 (2-Year) p-value
S. mutans 2.00 ± 0.54 2.10 ± 0.40 0.03
S. sobrinus 1.22 ± 0.57 1.41 ± 0.53 0.03
L. casei 1.50 ± 0.51 1.44 ± 0.74 0.02
L. fermentum 1.84 ± 0.32 1.86 ± 1.25 0.04

Conclusions

  • HAF toothpaste was more effective than fluoridated toothpaste in reducing acid production and levels of cariogenic bacteria.

  • HAF toothpaste contributed to a less acidogenic and less cariogenic oral environment.

  • The findings suggest HAF may be a viable alternative or complement to traditional fluoride toothpastes in preventing caries.

Discussion: Strengths and Limitations

Strengths:

  • Large sample size (n=610)

  • 24-month follow-up

  • Triple-blind design

  • Detailed microbial and pH measurements

Limitations:

  • Some data collection delayed due to COVID-19

  • Twice-daily at-home brushing was not supervised

  • Adherence monitoring relied partly on parental reporting

  • Results may not generalize beyond study population

Citation

Campus G, Cocco F, Wierichs RJ, et al. Effects of hydroxyapatite-containing toothpastes on some caries-related variables: a randomised clinical trial. Int Dent J. 2024;74(2):754–761.
https://pubmed.ncbi.nlm.nih.gov/

Simple Chart: Enamel Biofilm Acidogenicity

Toothpaste Group Minimum pH (2 Years) Max pH Drop (2 Years)
HAF1000 5.72 ± 0.22 1.00 ± 0.34
F1000 5.49 ± 0.32 1.06 ± 0.33
HAF1450 5.66 ± 0.36 1.05 ± 0.11
F1450 5.51 ± 0.38 1.01 ± 0.34
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