Effect of an acute maternal fluoride dose on fetal plasma fluoride levels and enamel fluoride uptake in guinea pigs

We conducted this study to measure maternal plasma, fetal plasma, and fetal enamel fluoride concentrations for four hours following an oral F dose to near-term pregnant guinea pigs. We placed female guinea pigs on de-ionized (Group I) or 3-ppm-F (Group II) drinking water prior to breeding and during gestation. On the 57th day of gestation, we administered a maternal dose of NaF solution (0.6 mg F/kg) by stomach tube. We collected samples of maternal plasma, fetal plasma, and fetal enamel at baseline, at 15 and 30 min, and at one, two, and four h after administration of the dose. We assayed samples for F using a modification of the micro-diffusion and ion-specific electrode method. Group I mean baseline F values were: maternal plasma, 0.016; fetal plasma, 0.002; and fetal enamel, 7.0 ppm. Group II mean values were: 0.055, 0.004, and 19.0 ppm. After the maternal fluoride dose, the mean maternal plasma [F] rose sharply for 30 to 60 min and declined to about 50% of peak values by four h. Fetal plasma [F] changed less in absolute values, but similarly to maternal changes relative to baseline. Fetal enamel mean [F] rose more in Group II than in Group I. Baseline F status had an important effect on F uptake in fetal enamel following an acute maternal fluoride dose.     

Presence of periodontal data in patient records of general practitioners

It has been reported that little diagnostic information concerning periodontal conditions is entered in patient records of general practitioners, but actual rates for such chart entries are unknown. Records of regular patients, seen at least annually, were randomly selected from the offices of 36 general practitioners in two North Carolina counties. In each office 80 records were selected for audit. After adjustment, the final sample consisted of 2488 audited records. Entries noting the presence or absence of 14 diagnostic conditions were identified for the five previous years and for the patient's most recent examination. The presence of a periodontal diagnosis or periodontal treatment plan was noted. The number of radiographic sets exposed in the previous five years and the age of the most recent set were determined for complete series/panoramic films and for bitewings. Across practices, the most frequent notations (20.5% within the past five years) concerned the presence of probing depths and calculus. Gingival bleeding (13%) and plaque (12%) were noted less frequently. A periodontal diagnosis was recorded in only 16.3% of the records. Annualized rates for radiographic sets were 0.09 for complete series/panoramic films and 0.50 for bitewings. These data suggest that, except for radiographs, the majority of patient records do not contain sufficient diagnostic information to describe patients' periodontal health.     

Nicotine effects on PGE2 and IL-1β release by LPS-treated human monocytes

Cigarette smoking is a major risk factor in the development and further progression of periodontitis. However, little is known regarding the pathogenesis of smoking-related periodontal diseases. The purpose of this study was to examine the effects of nicotine, alone and in combination with lipopolysaccharide (LPS), on monocyte secretion of bone-resorbing factors, PGE₂ and IL-1β. Peripheral blood monocytes (PBM) were isolated by counterflow centrifugal elutriation from 15 healthy, non-smoking donors. PBM were incubated for 24 h in RPMI 1640 containing nicotine (0, 50 μg/ml, I μg/ml, 10 μg/ml and 100 μg/ml) with or without 10 μg/ml Porphyromonas gingivalis LPS or Escherichia coli LPS. Culture supernatants were assayed for PGE₂ and IL-1β by ELISA. None of the nicotine preparations resulted in significant PBM secretion of PGE₂ and IL-1β above that of unstimulated cultures. However, PGE₂ release was potentiated 1.7-fold by the combination of P. gingivalis LPS and 10 μg/ml nicotine relative to P. gingivalis LPS alone (p<0.05, one-way ANOVA). Prostaglandin E₃ release also was potentiated 3.5-fold by P. gingivalis LPS and 100 μg/ml nicotine relative to P. gingivalis LPS alone (p<0.00001, one-way ANOVA) and 3.1-fold by E. coli LPS and 100 μg/ml nicotine relative to E. coli LPS alone (p<0.00001, I. one-way ANOVA). IL-1β secretion was lower for either LPS plus 100 μg/ml nicotine relative to LPS alone, although not significantly. These data demonstrate upregulation of LPS-mediated monocyte secretion of PGE₂ by nicotine and suggest a potential role for nicotine in periodontal disease pathogenesis.     

Toothbrushing force in relation to plaque removal

Abstract This was a 2-part study. The purpose of the 1st part was to examine the relationship between brushing force and plaque removal efficacy comparing a regular manual toothbrush (M) with an electric toothbrush the Braun Oral-B Plak Control* (B). The study consisted of a single oral prophylaxis followed by 5 experiments which differed solely in respect to toothbrushing force. At baseline (after 24-h plaque accumulation), the amount of dental plaque was evaluated and subsequently, the subject's mouth was brushed by a dental hygienist. Brushing was carried out in a random split-mouth order. Either the 1st and 3rd quadrants or the 2nd and 4th quadrants were brushed with 1 toothbrush and the 2 remaining quadrants with the other. The available time for the brushing procedure was 2 min. After brushing, the amount of remaining dental plaque was assessed. The force used in experiment 1 through 5 was 100, 150, 200, 250, 300 g, respectively. The results show that when brushing force is increased, more plaque is removed with either of the two brushes. Except for the high brushing force (300 g), the electric toothbrush removed more plaque than the manual brush. The purpose of the 2nd part was to evaluate the habitual brushing force which individuals use with various toothbrushes. Besides a manual toothbrush (M), 3 electric toothbrushes were examined, the Rotadent® (R). Interplak® (I) and Braun® (B). 20 subjects were selected on the basis of being ‘good brushers” (plaque score at screening <25%). At baseline, each subject randomly received 1 of the 4 brushes. They were allowed a training period of 3 weeks at the end of which they were asked to abstain from brushing for at least 24 h. The plaque (Turesky modification of the Quigley & Hein) was scored, after which the subjects brushed their teeth (2 min) with the assigned toothbrush equipped with a strain gauge. A computer set–up measured (100 Hz) and calculated the mean brushing force. After brushing, the amount of remaining plaque was assessed. The design of the study was a 4-way cross-over. The results show that with a manual brush, considerably more force is used than with the electric brushes (R=96. 1 = 119. B= 146, M=273). No significant relation between brushing force and plaque removal was demonstrated for any of the brushes.     

The effect of porcelain laminate veneers on gingival health and bacterial plaque characteristics

Abstract. The aim of this study was to evaluate the response of microbial plaque and gingival inflammation to the placement of porcelain laminate veneers on anterior teeth. 9 patients, 7 female and 2 male (mean age of 30 years), with a total of 35 veneers were examined. The volume of gingival crevicular fluid (GCF), level of neutral proteolytic enzyme activity, gingival index (GI), plaque index (PII) and plaque bacteria vitality were measured at baseline and after the placement of veneers. The volume of GCF increased after the placement of veneers ( p =0.03). No statistically significant differences were found in proteolytic enzyme activity or GI ( p >0.05). There were statistically significant reductions in PII ( p =0.000) and plaque bacteria vitality ( p =0.018). Further research is required to assess the long-term influence of porcelain laminate veneers on gingival health and microbial plaque characteristics.     

Molecular basis of salivary proline-rich protein and peptide synthesis: cell-free translations and processing of human and macaque statherin mRNAs and partial amino acid sequence of their signal peptides

Acidic proline-rich phosphoproteins and phosphopeptides are abundant components of parotid and submandibular salivary secretions in man and in the subhuman primate, Macaca fascicularis. The major acidic proline-rich proteins and the proline-rich phosphopeptide, statherin, of man and macaques have been shown to be potent inhibitors of calcium phosphate precipitation and are thought to function in the oral environment by maintaining saliva supersaturated with respect to calcium phosphate salts. Little is known about the biosynthesis of these proline-rich phosphoproteins and peptides, and the aim of the present work was to determine the structural relationship between statherin precursors and native human and macaque statherin. RNA was isolated from human submandibular gland, and poly(A+) mRNA was selected by affinity chromatography on oligo(dT) cellulose and translated in a reticulocyte lysate. Electrophoretic analysis of the translation products revealed that this mRNA directed the synthesis of a large number of polypeptides with Mrs ranging from 5000 to 70,000. Immunoprecipitates, prepared with an antiserum directed against human statherin, contained a single component with a Mr of 7800, approximately 2000 daltons larger than native statherin. Radiosequencing of the in vitro precursor of statherin in immunoprecipitates demonstrated the presence of a 19-residue signal peptide. These results suggest that statherin is derived from a unique structural gene, and does not result from proteolytic processing of a large polyprotein precursor.     

Lingual changes in ageing mice by light- and scanning electron-microscopy

Tongues from young, old and senescent Swiss-Webster white mice were compared. Sections and tissues were taken from the anterior, posterior, and ventral regions. The epithelium became atrophic and hyperkeratotic in the senescent animals. The filiform papillae were blunted, atrophic and disorganized across the entire dorsal surface in the older animals. The ventral aspect in the senescent animals had thinning epithelium, a hyperchromatic germinal layer, and a roughened, disorganized surface.     

Factors affecting dental utilization of elders aged 75 years or older

Data collected from 496 elders aged 75 years or older participating in the Massachusetts Health Care Panel Study were analyzed by means of multiple regression to determine the principal predictors of perceived need for care and of dental users. The relationship between perceived need and use of services also was examined. The significant variables influencing perceived need in elders were poorer self-perceived oral health, having some teeth, and reporting a dental visit within two years. Dental users were best predicted by dentate status, a history of alcohol consumption, and perceived need for care. Although the variables of perceived need and being a user each influenced the other, both were more influenced by a common significant predictor variable, dentate status.