Hardy Limeback

OBJECTIVES: To develop and validate an instrument to measure the functional oral health literacy of adults. METHODS: For the generation of items different dental patient educational materials and text types were selected that had reading levels similar to materials used for the Test of Functional Health Literacy in Adults (TOFHLA) which was the model for our Oral Health Literacy Instrument (OHLI). The OHLI contains reading comprehension and numeracy sections. The reading comprehension section is a 38-item test with words omitted from one passage on dental caries and another on periodontal disease. The numeracy section has 19 items to test comprehension of directions for taking common prescriptions associated with dental treatment, postextraction instructions and dental appointments. We also developed a 17-item oral health knowledge test. The OHLI, the TOFHLA, the oral health knowledge test and a brief questionnaire were administered to a convenience sample of 100 patients. Internal reliability of OHLI was assessed with Cronbach's alpha. Test-retest reliability was examined by intra-class correlation coefficient (ICC). Concurrent validity was tested by comparing OHLI scores across categories of education level and frequency of dental visits. Construct validity was assessed by correlating OHLI scores with TOFHLA scores and with the oral health knowledge scores using Spearman's rho (rho) and multiple linear regression. RESULTS: Participants averaged 39 years (SD = 12.4); 73% were female; 64% had college/university education; 40% visited a dentist every 3-6 months. Total OHLI and TOFHLA weighted mean scores were 87.2 and 91.7, respectively (possible range 0-100). The Cronbach's alpha values were high (>0.7) for OHLI and its components. The ICC values indicated good agreement between the test and retest results for OHLI and the oral health knowledge test. Patients visiting a dentist every 3-6 months had significantly higher levels of oral health literacy than those visiting only when they felt pain. The association between OHLI and education level was not significant. OHLI scores were significantly correlated with the scores on the TOFHLA (rho = 0.613) and the test of oral health knowledge (rho = 0.573). These associations remained significant in multiple regression models. CONCLUSION: Initial testing of OHLI suggested that it is a valid and reliable instrument to evaluate oral health literacy among adults, although additional work is needed to investigate the instrument's predictive validity and sensitivity to change using oral health outcomes with population groups known to be at high risk of low functional oral health literacy.

During tooth formation nearly all of the protein matrix of enamel is removed before final mineralization. To study this process, enamel proteins and proteinases were extracted from pig enamel at different stages of tooth development. In the enamel maturation zones, the major enamel matrix proteins, the amelogenins, were rapidly processed and removed. Possibly associated with this process in vivo are two groups of proteinases which were identified in the enamel extracts by enzymography using amelogenin-substrate and gelatin-substrate polyacrylamide gels and by the degradation in vitro of guanidinium chloride-extracted amelogenins. One group of proteinases with gelatinolytic activity consisted of several neutral metalloendoproteinases having Mr values from 62,000 to 130,000. These proteinases were inactive against amelogenins, casein and albumin, and were present in approximately equal proportions in enamel at all developmental stages. In the other group, two serine proteinases, with apparent non-reduced Mr of 31,000 and 36,000 exhibited amelogeninolytic activity. The substrate preference of the enamel serine proteinases was indicated by their limited degradation of casein and their inability to degrade gelatin and albumin. Contrasting with the distribution of the metalloendoproteinase enzymes, the serine proteinases were found only in the enamel scrapings taken from late-maturing enamel. The amelogenin degradation patterns in vivo, observed in the enamel scrapings, were similar to those produced in assays in vitro using partially purified fractions of enamel proteinases and amelogenin substrate. Together, these data strongly indicate an important role for the serine proteinases, and possibly the gelatinolytic proteinases, in the organized processing of the enamel protein matrix during enamel formation.

A rat osteosarcoma cell clone (ROS 17/2), and osteoblast-enriched populations from rat calvaria cultured in the presence of concanavalin A, have been shown to produce latent collagenase and collagenase inhibitors. The enzymes and inhibitor activities from the ROS 17/2 cells were concentrated by ammonium sulphate precipitation and separated by gel filtration on AcA 54 resin. The size of the latent collagenase (Mr approximately equal to 58000) was reduced on conversion to active enzyme (Mr approximately equal to 48000) by p-aminophenylmercuric acetate. Latent and active forms of gelatinase activity, similar in size to the corresponding forms of collagenase, were also resolved. The collagenase inhibitor activity, which was sensitive to organomercurials, was recovered in two peaks (Mr approximately equal to 68000 and 30000). The active collagenase cleaved interstitial collagens (type I = III greater than II) producing typical 3/4 and 1/4 fragments. This activity was inhibited by the metal ion chelators ethylenediaminetetraacetic acid and o-phenanthroline. Additional specific cleavages of native collagen were also observed which, from the susceptibility of this activity to phenylmethylsulphonyl fluoride, leupeptin and antipain, suggested the presence of a second collagenolytic enzyme. This synthesis of collagenolytic enzymes by these osteoblast-like cells suggests that individual osteoblasts, like fibroblasts, are capable of both synthesizing and degrading their respective organic matrices in vivo.