M Beerens

EFFECTS OF MI PASTE PLUS ® : A 12-MONTHS FOLLOW-UP 5 83 from the data recording files in a locked closet. Data were collected and coded based on participants’ ID number and a sequential number in order of date of study visits. Data analysis was performed blind for group allocation. Participants received neutral-coloured concealed toothpaste tubes marked A or B for home use; • Paste A contained either CPP-ACP + sodium fluoride [0.2 % w/w; 900 p.p.m.; (MI Paste Plus ® 35 ml, Recaldent; GC Benelux Europe, Leuven, Belgium)], or • Paste B contained fluoride-free control paste + calcium (Ultradent 100 ml; Kruidvat NL, Renswoude, The Netherlands). Participants were instructed to use their respective paste once a day at bedtime after tooth brushing. Participants received verbal and written instructions on product use and oral hygiene procedures by a dental hygienist. They were advised how to brush properly using a normal toothpaste (i.e. at least twice a day, either with a hand toothbrush or an electric toothbrush for at least 2 minutes). No additional fluoride was to be applied. Participants were informed to apply at least a pea-size amount to the tooth surfaces in each arch using a clean, dry finger and keep the study product in the mouth for as long as possible. Participants were instructed not to rinse afterwards. Compliance was checked by questions regarding product use asked at each visit. Furthermore, participants were asked to bring their study paste to each visit. Prior to each study visit, they were asked to refrain from tooth brushing from the evening before the visit and from eating and drinking 2 hours prior to the visit. Each visit started with plaque sampling. After plaque sampling, the tooth surfaces were cleaned and polished for adequate viewing of WSL in the QLF and digital oral photographs. The participants’ dentists were informed of their patients’ participation and were asked not to administer additional fluoride during this investigation. They were further asked to contact the study investigator if restorations were made on the buccal surfaces. Subjects were informed that they would receive either the MI Paste Plus ® paste or the control paste with a different form of calcium delivery. The patients and the observer were blinded with respect to the content of tube A or B. Examiners M.W.B., F.B., and MHV were also blinded.