Increased adhesion of peripheral blood neutrophils from patients with localized juvenile periodontitis

Adhesion of peripheral blood neutrophils from 5 patients with localized juvenile periodontitis (LJP) and age- and gender-matched healthy controls was measured using a semi-automated 96-well microtiter plate assay method. Both unstimulated and formyl-methionyl-leucyl-phenylalanine (FMLP, 10–1000 nM)-stimulated neutrophils from LJP patients showed in general higher adhesion than did their controls. After 15–60 min incubation with 100 and 1000 nM FMLP the numbers of adherent cells were significantly (p<0.05), 2.1–2.6-fold higher in LJP patients than in controls. Neutrophils from these LJP patients showed also enhanced respiratory burst activity in response to unopsonized zymosan stimulation. To test whether a decrease in intracellular diacylglycerol (DAG) kinase activity could account for the increased neutrophil adhesion of LJP patients normal neutrophils were treated with R59949 (10 μM), a DAG-kinase inhibitor. Both unstimulated and FMLP-stimulated normal neutrophiis showed significantly (p<0.05) enhanced adhesion after R59949-treatment. Taken together, our data indicate that neutrophils from the 5 LJP patients investigated here exhibit 2 parallel hyperactivities, namely increased adhesion and enhanced production of reactive oxygen species. Furthermore, our present and previous (Hurttia et al, J Periodont Res 1997; 32: 401-407) results suggest that the observed neutrophil functional abnormalities in some LJP patients may be associated with decreased cellular DAG-kinase activity. It is proposed that the hyperadherent and -active neutrophils may promote the development of LJP by causing tissue damage in the periodontium.     

Identification of calprotectin, a calcium binding leukocyte protein, in human dental calculus matrix

Calprotectin is a calcium binding protein produced by leukocytes, macrophages and epithelial cells, and its levels in several tissues increase during infections and in many inflamed areas, suggesting that it may be an indicator of inflammatory activity. Osteopontin is a prominent phosphorylated glycoprotein in bone matrix, having calcium binding capacity. Recently, it has been reported that calprotectin and osteopontin are present in urinary stones (pathological mineralized masses in the body), and that these proteins may be involved in their formation. Dental calculus formed by mineralization of dental plaque is an inflammatory factor which may contribute to periodontal disease. It contains many organic components involved in mineralization. We recently found osteopontin molecules in human dental calculus and suggested that the components of its matrix may be similar to those of urinary stones. In this study, we investigated the presence of calprotectin in human dental calculus by immunohistochemical and immunoblotting analyses using a specific antibody for calprotectin. After fixation and demineralization of dental calculi adhered to tooth roots, sections embedded in paraffin were immunoreacted with the antibody for calprotectin and positive immunostaining for calprotectin was observed. Dental calculus proteins were then extracted with EDTA and separated by electrophoresis on 15% polyacrylamide gels. By immunoblotting analysis, 3 or 4 bands were observed at 11, 14.5, 22–25, 28 or 36.5 kDa and these patterns corresponded to those of calprotectin subunits. When non-immune rabbit serum was used instead of calprotectin-specific antibody as a negative control, no immunoreactivity was observed. These findings indicate that calprotectin is associated not only with antibacterial action but also with calcium binding capacity during dental calculus formation.     

Effectiveness of chlorhexidine and sodium fluoride in reducing dentin hypersensitivity.

This investigation was conducted to evaluate the effect of chlorhexidine, sodium fluoride, and sequential rinses of chlorhexidine (Cx) and sodium fluoride (NaF) on dentin hypersensitivity. Forty-four adult patients with dentin hypersensitivity on three teeth were randomly assigned to receive one of four treatment rinses: (1) placebo; (2) 0.12% Cx; (3) 0.2% NaF; or (4) 0.12% Cx plus 0.2 NaF. Patients' responses to cold stimulation were recorded at baseline, two weeks, and four weeks. Pain response was quantified by applying successively decreasing temperature intervals of water (20 degrees C, 15 degrees C, 10 degrees C, 5 degrees C, and 0 degrees C) to exposed dentin. Plaque Index (Silness and L?e) was recorded at baseline only. Data on dentin sensitivity over time were analyzed using a repeated measures ANOVA. This ANOVA was conducted to generate an error term for calculation of Dunn's multiple mean comparison test. A Spearman rank order test was computed to assess correlation between plaque and hypersensitivity at baseline. Results showed the Cx and NaF rinses alone significantly reduced hypersensitivity (p less than .01) at four weeks compared to baseline. Sequential Cx and NaF rinses significantly decreased sensitivity (p less than .01) at both the two- and four-week intervals compared to baseline. At the four-week interval, the sequential Cx/NaF rinse group showed a significantly greater reduction (p less than .01) in hypersensitivity response when compared to placebo. Cx alone, or NaF alone groups. A moderate, positive correlation (r = 0.55) was demonstrated between plaque and dentin hypersensitivity. This was statistically significant at the (p less than .05) level.     

Effect of dentin adhesives on sealant bond strength.

This study evaluated the effect of four dentin adhesives on sealant shear bond strength. Five groups of 15 human extracted teeth (75 in total) were prepared to receive the following treatments: group 1, sealant only; group 2, sealant plus gluma primer; group 3, sealant plus gluma primer and sealer, group 4, sealant plus C & B Metabond. Each tooth had a bonding site prepared for each material by grinding a flat plane on the enamel with 600 grit. The enamel site was etched for 30 seconds, washed for 20 seconds and dried. Each material was mixed according to the instructions of the manufacturer. The sealant (Concise) was placed in a nylon cylinder, light-cured, stored in distilled water for 24 hours, thermocycled (100 cycles at 5 to 55 degrees C) and shear bond strength determined with a knife-edge blade in an Instron running at a crosshead speed of 0.5 mm/min. The results in MPa were: group 1, 11.8 +/- 4.5; group 2, 12.3 +/- 5.0; group 3, 10.3 +/- 1.9; group 4, 12.5 +/- 8.6; and group 5, 15.8 +/- 5.2. Statistically (ANOVA one way) there was no significant difference in the groups.     

Dose-responsive characteristics of meperidine sedation in preschool children

Using double-blind conditions, 60 uncooperative and fearful preschool children (24-66 months) received intramuscular injections of meperidine 0.25, 0.50, 1.00 mg/lb or placebo prior to restorative dental treatment. Behavior was assessed by the dentist and an independent observer during five specific treatment procedures. Behavioral ratings found meperidine to be an effective sedative, with 0.50 mg/lb and 1.00 mg/lb being significantly more effective than placebo (P less than 0.05, Kruskal-Wallis). Children receiving 1.0 mg/lb of meperidine had significantly more nausea and vomiting than patients receiving lower doses of the drug (P less than 0.05, Chisquare). Physiologic monitoring demonstrated that the highest dose of meperidine was associated with transient drops in arterial oxygen saturation. Meperidine sedation was found to be more effective for older children (37-66 months) and for children initially rated as being only moderately uncooperative and fearful.     

Planning and control of vertical dimension in Le Fort I osteotomies

Depending on the different anatomy of the soft and hard tissues, concavity or convexity of the face, measurements of inferior or superior repositioning of the maxilla may be less predictable when using only the osteotomy site for this calculation. A more reliable method would be to measure the distance from a bone mark in the forehead to the incisor edges. This method has been practiced by our clinic during the past five years. The method is thought to offer a more accurate estimation of the position of the upper anterior teeth in relation to the lip, although one must anticipate a certain degree of postoperative relapse especially concerning inferior repositioning. In order to evaluate the accuracy of our method, a comparison has been made of the calculated vertical repositioning and the surgical results in two groups. In group I (12 individuals) conventional estimation of maxillary repositioning in the osteotomy line was made; in group II (12 individuals) measurements were made from a bone mark on the forehead to the incisor edges. A satisfying correlation was found between calculated and achieved results in both groups. In comparison between calculated and immediate postoperative measurements the results showed no statistically significant difference between the two methods.     

Dental hygiene student. Interest in advanced education

This paper reports the results of a 1985 survey of certificate/associate degree students' interest in advanced education: baccalaureate degree completion and non-degree granting residency programs. Subjects included first- and second-year dental hygiene students enrolled in 12 vocational, community college, state, and research university institutions in a five-state region in the upper Midwest. The data collection instrument consisted of a 12-item mailed questionnaire. One hundred percent program and 78.7% student response rates were achieved. Results indicate that respondents are interested in degree completion and non-degree granting residency programs. Interest varied by age and by type of institution in which respondents were completing their dental hygiene education. While younger respondents were more likely to express interest in advanced education, respondents over the age of 30 were generally interested or undecided. Overall, respondents indicated slightly different areas of interest for degree completion versus residency programs. In general, respondents indicated an interest in pursuing advanced education on a part-time, evening basis, within five years of completion of their basic dental hygiene education. Cost, time, and family commitments were identified by respondents as major barriers to continuing their education.     

Investigation of self-etching dentin primers

In order to simplify the dentin bonding procedures by combining the dentin cleansing and dentin primer steps, we investigated the efficacy of the four acidic monomers--monomethacryloxyethyl succinate (MES), dimethacryloxyethyl phosphate (DMEP), tertiary butylacrylamide sulfonic acid (TBAS), and 4-methacryloxyethyl trimellitic anhydride (4-META), diluted in 35% hydroxyethyl methacrylate (HEMA) solution--by measuring the maximum contraction gap of the visible-light-curing composite (Silux 3M, St. Paul, MN, USA) in the cylindrical dentin cavity mediated by the bonding agent (Clearfil New Bond, Kuraray Co., Osaka, Japan). More than five of the ten specimens which were pre-treated with an aqueous mixture of 35% HEMA and four functional monomers at the concentrations of 0.1 M, 0.2 M, and 0.3 M showed a complete marginal adaptation, and this result was the same as in the control group in which the cavities were cleansed and pre-treated with 0.5 M EDTA and 35% HEMA, respectively. Moreover, the procedures were simpler. Therefore, these four monomers are considered to be effective as self-etching primers.     

Heterotropic brain tissue in the oropharynx. Report of a case

A case of a 7-month-old boy with oropharyngeal heterotropic brain tissue is presented. The lesion, which protruded from the right side of the oropharynx, occupied the oropharyngeal space and pressed the tongue forward and downward. A cranial computed tomograph showed that the mass had some radiolucent areas. Surgical treatment was performed to remove the respiratory and feeding distress. Histologically, the lesions consisted of matured glial cells, ependymal clefts with choroid plexus, and scattered pigmented cells in a part of lining cells of cyst wall.