Investigation of the cleaning performance of commercial orthodontic cleaning tablets regarding biofilm removal on PMMA test specimens : An ex vivo study

Abstract

Purpose: The purpose of this ex vivo study was to compare the cleaning performance of three commercially available orthodontic cleaners on polymethyl methacrylate (PMMA) test specimens covered with biofilm.

Methods: Twenty subjects wore an individually manufactured vacuum-formed maxillary splint with four integrated PMMA test specimens for 7 days. The four test specimens were located on the buccal surfaces of the maxillary molars. After a 7-day wearing period, the PMMA test specimens colonized by biofilm were divided into two halves. One half was placed in 150 ml of tap water or in 150 ml of cleaning solution of the cleaners Retainer Brite® (Dentsply International Raintree Essix, Sarasota, FL, USA), Kukis® Xpress (Reckitt Benckiser, Heidelberg, Germany) or Dontodent (Propack, Heidelberg, Germany) while the other half remained uncleaned. The modified o‑phthaldialdehyde (OPA) method was used to determine the amount of protein on both halves of the test specimens. The difference was tested for significance as a measure of the cleaning effect using a paired sample t‑test.

Results: The cleaning performance of the three orthodontic cleaners was higher than the cleaning performance of tap water (mean 25.9 ± 6.5%). While Retainer Brite® (mean 54.5 ± 7.1%) removed significantly more biofilm than Dontodent (mean 41.5 ± 9.2%, p < 0.001) and Kukis® Xpress (mean 39.9 ± 11.5%, p < 0.001), there was no significant difference in the cleaning performance between Kukis® Xpress and Dontodent (p = 1).

Conclusion: Seven-day-old biofilm is only removed partially by the investigated orthodontic cleaners, so that they are not suitable as the only measure for removing established biofilms.

Keywords: Denture hygiene; Polymethyl methacrylate; Removable orthodontic appliances; Removal of biofilms; o‑phthaldialdehyde (OPA) method.

Fig. 1

Vacuum-formed maxillary splint with four integrated test specimens located on the buccal surface of the molars. The access to the test specimens was covered with wax for better visualisation and replaced with silicone for the trials. The location of the test specimens was numbered with the letters A–D. The allocation of the cleaners to the test specimens rotated according to a predefined protocol Tiefziehschiene für den Oberkiefer mit 4 Prüfkörpern lokalisiert an den bukkalen Flächen der Molaren. Der Zugang zu den Prüfkörpern wurde zur besseren Visualisierung mit Wachs abgedeckt und für die Probandenversuche durch Silikon ersetzt. Die Lokalisation der Prüfkörper wurde mit den Buchstaben A–D nummeriert. Die Zuordnung der Reiniger zum Prüfkörper rotierte nach einem vorher festgelegten Protokoll

Fig. 2

Boxplot diagram showing the reduction of protein in % on the surface of the polymethyl methacrylate (PMMA) test specimens after cleaning compared to the uncleaned control group. Mean values ± standard deviation: Retainer Brite® 54.5 ± 7.1%, Kukis® Xpress 39.9 ± 11.5%, Dontodent 41.5 ± 9.2% and tap water 25.9 ± 6.5%. Median values: Retainer Brite® 54.9%, Kukis® Xpress 38.8%, Dontodent 39.9% and tap water 26.5% Boxplot-Diagramm, das die Proteinreduktion in % auf der Oberfläche der PMMA(Polymethylmethacrylat)-Prüfkörper nach Reinigung im Vergleich zur ungereinigten Kontrollgruppe darstellt. Mittelwerte ± Standardabweichung: Retainer Brite® 54,5 ± 7,1%, Kukis® Xpress 39,9 ± 11,5%, Dontodent 41,5 ± 9,2% und Leitungswasser 25,9 ± 6,5%. Medianwerte: Retainer Brite® 54,9%, Kukis® Xpress 38,8%, Dontodent 39,9% und Leitungswasser 26,5%

Fig. 3

Boxplots illustrating the distribution of the amount of protein in the different cleaning groups before and after cleaning. values 1.5 × IQR (interquartile range) above the third quartile. circles Outliners Boxplots zur Darstellung der Verteilung der Proteinmengen in den verschiedenen Reinigergruppen vor und nach Reinigung. Werte 1,5 × IQR (Interquartilsabstand) über dem dritten Quartil. Kreise Ausreißer