In vitro effect of human saliva on the output of fluoride from controlled-release devices.
This study was designed to determine the in vitro fluoride output from controlled-release devices in stimulated, whole human saliva, and to assess changes in the salivary calcium concentration following immersion of the devices. Twenty fluoride (F) controlled-release devices of the hydroxyethyl methacrylate (HEMA)/methyl methacrylate (MMA)-type were employed. Each was designed to release 1-2 mg F per day. All devices were placed individually in 10.0 ml of deionized water for 3 days to assess baseline F output. Seven devices with markedly high or low output were discarded. During days 4-13, three of the remaining 13 devices were placed individually in 10.0 ml of stimulated, whole saliva donated by three volunteers. All devices were returned to deionized water during days 14-17. All solutions were replaced daily with fresh solutions, and each test tube was inverted once every 24 hr. The study was conducted at 19-21 degrees C. Fluoride concentration of the deionized water and human saliva was assessed by ion-specific electrode; calcium concentration of the saliva was assessed pre- and postimmersion by flame atomic absorption spectrometry. The fluoride output of the devices placed in saliva decreased to 36% of their baseline rates (P < 0.001). The calcium concentration of the human saliva decreased from a mean preimmersion value of 3.58 mg/100 ml (+/- 0.63 SD) to a postimmersion value of 2.64 (+/- 1.12 SD; P < 0.001). These results suggest an interaction between the fluoride released by the devices and calcium in the saliva.(ABSTRACT TRUNCATED AT 250 WORDS)
Adair
S M
SM
Department of Pediatric Dentistry, Medical College of Georgia, Augusta.
Whitford
G M
GM
Hanes
C M
CM
D001031:Apatites / Q000032:analysis / Q000737:chemistry; D002118:Calcium / Q000032:analysis; D002124:Calcium Fluoride / Q000032:analysis / Q000737:chemistry; D003692:Delayed-Action Preparations; D004058:Diffusion; D004337:Drug Carriers; D005459:Fluorides / Q000032:analysis / Q000737:chemistry*; D006801:Humans; D007101:Immersion; D008689:Methacrylates / Q000737:chemistry; D020366:Methylmethacrylate; D008768:Methylmethacrylates / Q000737:chemistry; D012463:Saliva / Q000737:chemistry / Q000502:physiology*; D012969:Sodium Fluoride / Q000737:chemistry; D013054:Spectrophotometry, Atomic; D013997:Time Factors; D014867:Water
D001031:Apatites; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D008689:Methacrylates; D008768:Methylmethacrylates; D014867:Water; D020366:Methylmethacrylate; C005044:hydroxyethyl methacrylate; D012969:Sodium Fluoride; C025105:fluorapatite; D002124:Calcium Fluoride; D005459:Fluorides; D002118:Calcium