Impact of the Daily Use of a Microcrystal Hydroxyapatite Dentifrice on De Novo Plaque Formation and Clinical/Microbiological Parameters of Periodontal Health. A Randomized Trial

Abstract

Aim: This 12-week prospective, randomized, double-blind, two-center trial evaluated the impact of a microcrystalline zinc hydroxyapatite (mHA) dentifrice on plaque formation rate (PFR) in chronic periodontitis patients. We hypothesized that mHA precipitates cause delayed plaque development when compared to a fluoridated control (AmF/SnF2), and therefore would improve periodontal health.

Material & methods: At baseline and after 4 and 12 weeks, PFR and other clinical and microbiological parameters were recorded. Seventy periodontitis patients received a mHA or AmF/SnF2 dentifrice as daily oral care without hygiene instructions. Four weeks after baseline, participants received full mouth debridement and continued using the dentifrices for another 8 weeks.

Results: Primary outcome PFR did not change statistically significantly from baseline to weeks 4 and 12, neither in mHA (n = 33; 51.7±17.2% vs. 48.5±16.65% vs. 48.4±19.9%) nor in AmF/SnF2-group (n = 34; 52.3±17.5% vs. 52.5±21.3% vs. 46.1±21.8%). Secondary clinical parameters such as plaque control record, gingival index, bleeding on probing, and pocket probing depth improved, but between-group differences were not statistically significant. Microbiological analyses showed similar slight decreases in colony-forming units in both groups.

Conclusion: In patients with mild-to-moderate periodontitis, periodontal therapy and use of a mHA-or AmF/SnF2 dentifrice without instructions induced comparable improvements in periodontal health but did not significantly reduce the PFR.

Trial registration: ClincalTrials.gov NCT02697539.

Conflict of interest statement

Competing Interests: All study affairs have been exclusively funded by Dr. Kurt Wolff GmbH & CO. KG, Johanneswerkstr. 34 – 36, 33611 Bielefeld, Germany. There are no patents, products in development, or marketed products to declare. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors.

Figures

Fig 1. Study design.

Visits 2b, 3b, and 4b were scheduled 24 hours following visit 2a, 3a, and 4a, respectively. PFR: Plaque formation rate; Test: microcrystalline zinc hydroxyapatite (mHA) dentifrice; Control: fluoridated control (AmF/SnF2) dentifrice.

Fig 2. Sample tooth selection.

Selection process: According to the randomization list, sample teeth are selected in a clockwise (CW) or counter clockwise (CC) direction. Example: For clockwise selection, start at the upper right quadrant from the most distal tooth going towards the mesial (CW, mandatory turn 1)

1. Select the most distal tooth in this quadrant that meets the criteria (at least 1 site with at least 1 site with PPDs of ≥ 4 mm); if 1 tooth is selected or none meets the criteria then

2. continue clockwise in the upper left quadrant and now select the most mesial tooth that meets the inclusion criteria, if 1 tooth is selected or none meets the criteria,

3. continue clockwise in the lower left quadrant and select the most distal tooth that meets the inclusion criteria, if 1 tooth is selected or none meets the criteria,

4. continue clockwise in the lower right quadrant and select the most mesial tooth that meets the inclusion criteria, stop if 1 tooth in each quadrant has been selected, if less than 4 teeth have been selected,

5. continue clockwise (optional turn 2), and start in the upper left quadrant going from mesial towards distal,

6. continue clockwise with optional turns 3 and 4 until a total number of 4 sample teeth have been included.

For counter clockwise proceed as indicated in the figure above.

Fig 3. Patient flow chart (mHA: microcrystalline zinc hydroxyapatite dentifrice, AmF/SnF2: aminefluoride/stannous fluoride).