Effect of Chewing a Calcium Supplement Before Fluoride Rinse on Salivary Fluoride

The anticaries effect of fluoride is through the increase in fluoride presence and retention in the oral fluids, reducing dental demineralization and enhancing remineralization. Previous studies showed that a preapplication of calcium (in a rinse) prior to administration of fluoride greatly enhances fluoride concentration in the mouth and the anticaries effect of fluoride. The hypothesis of this study is that the same can be achieved by chewing a calcium supplement prior to a fluoride rinse. The first goal is to determine if chewing these calcium supplements will increase calcium concentration in the oral fluids above baseline levels. Secondly, the calcium supplement with the highest calcium release will be tested before a fluoride rinse to assess the increased retention of fluoride in the oral fluids when compared with the fluoride rinse alone. In both parts, healthy volunteers will participate and saliva will be collected to assess calcium and fluoride concentration.

Participants were given one of 4 different treatments to chew: a negative control group and 3 calcium supplements with different calcium compositions. Participants were randomized to determine the sequence of exposure to the different treatments.

Participants rinsed with an over the counter sodium fluoride rinse for 1 min, after having chewed a candy (negative control), a calcium calcium carbonate or a calcium citrate supplement.

A chewable candy chewed for 30 seconds, immediately followed by a 1 minute rinse with an over the counter sodium fluoride mouthwash, at a concentration of 0.05% (226 parts per millim (ppm) of fluoride).

A calcium carbonate supplement chewed for 30 seconds, immediately followed by a 1 minute rinse with an over the counter sodium fluoride mouthwash, at a concentration of 0.05% (226 parts per millim (ppm) of fluoride).

A calcium citrate supplement chewed for 30 seconds, immediately followed by a 1 minute rinse with an over the counter sodium fluoride mouthwash, at a concentration of 0.05% (226 parts per millim (ppm) of fluoride).

Saliva collected as one spit, immediately before chewing one of the calcium supplements to be tested in Arm 1. Calcium concentration determined using a colorimetric method.

Saliva and remnants of the chewed calcium supplement collected at the end of the chewing period (30 seconds) in Arm 1. Calcium concentration determined using a colorimetric method.

Saliva collected as one spit, 15 seconds after chewing the calcium supplement in Arm 1. Calcium concentration determined using a colorimetric method.

Saliva collected as one spit, 30 seconds after chewing the calcium supplement in Arm 1. Calcium concentration determined using a colorimetric method.

Saliva collected as one spit, 45 seconds after chewing the calcium supplement in Arm 1. Calcium concentration determined using a colorimetric method.

Saliva collected as one spit, 60 seconds after chewing the calcium supplement in Arm 1. Calcium concentration determined using a colorimetric method.

Saliva collected as one spit, 120 seconds after chewing the calcium supplement in Arm 1. Calcium concentration determined using a colorimetric method.

Saliva collected as one spit, 180 seconds after chewing the calcium supplement in Arm 1. Calcium concentration determined using a colorimetric method.

Saliva collected as one spit, 240 seconds after chewing the calcium supplement in Arm 1. Calcium concentration determined using a colorimetric method.

Saliva collected as one spit, 300 seconds after chewing the calcium supplement in Arm 1. Calcium concentration determined using a colorimetric method.

Calcium concentration in saliva collected at baseline (before chewing the supplements), and 15, 30, 45, 60, 120, 180, 240 and 300 seconds after chewing the supplements in Arm 1 expressed as the area under the curve of calcium concentration in saliva as a function of time (milimolar x min).

Saliva will be collected for 2 min, immediately before chewing a calcium supplement and/or rinse with the fluoride mouthrinse in Arm 2. Fluoride concentration will be determined using an ion-specific electrode.

Saliva and remnants of the fluoride mouth rinse collected at the end of the rinsing period (1 minute) in Arm 2. Fluoride concentration determined using an ion-specific electrode.

Saliva will be collected for 2 min, 5 min after chewing a calcium supplement and/or rinse with the fluoride mouthrinse in Arm 2. Fluoride concentration will be determined using an ion-specific electrode.

Saliva collected for 2 min, 15 min after chewing a calcium supplement and/or rinse with the fluoride mouthrinse in Arm 2. Fluoride concentration determined using an ion-specific electrode.

Saliva collected for 2 min, 30 min after chewing a calcium supplement and/or rinse with the fluoride mouthrinse in Arm 2. Fluoride concentration determined using an ion-specific electrode.

Saliva collected for 2 min, 60 min after chewing a calcium supplement and/or rinse with the fluoride mouthrinse in Arm 2. Fluoride concentration determined using an ion-specific electrode.

Saliva collected for 2 min, 120 min after chewing a calcium supplement and/or rinse with the fluoride mouthrinse in Arm 2. Fluoride concentration determined using an ion-specific electrode.

Fluoride concentration in saliva collected at baseline (before treatments), and 0, 5, 15, 30, 60 and 120 minutes after chewing the supplements and/or rinsing the fluoride mouthrinse in Arm 2 expressed as the area under the curve of fluoride concentration in saliva as a function of time (micromolar x min).

Inclusion Criteria: Provision of signed and dated informed consent form Stated willingness to comply with all study procedures and availability for the duration of the study Reported good general health Reported good oral health Having at least 20 teeth in the mouth, being at least 4 (natural or crowned) teeth in all four quadrants of the mouth Having normal salivary flow rate according to direct flow rate determination methods Agreement to adhere to the study protocol Exclusion Criteria: Unable to understand and/or follow study instructions Hyposalivation Active periodontitis, identified by frequent bleeding of the gums Oral pain In need of urgent dental care